diff options
Diffstat (limited to 'Documentation')
66 files changed, 2781 insertions, 610 deletions
diff --git a/Documentation/ABI/stable/firewire-cdev b/Documentation/ABI/stable/firewire-cdev new file mode 100644 index 00000000000..16d03082736 --- /dev/null +++ b/Documentation/ABI/stable/firewire-cdev @@ -0,0 +1,103 @@ +What: /dev/fw[0-9]+ +Date: May 2007 +KernelVersion: 2.6.22 +Contact: linux1394-devel@lists.sourceforge.net +Description: + The character device files /dev/fw* are the interface between + firewire-core and IEEE 1394 device drivers implemented in + userspace. The ioctl(2)- and read(2)-based ABI is defined and + documented in <linux/firewire-cdev.h>. + + This ABI offers most of the features which firewire-core also + exposes to kernelspace IEEE 1394 drivers. + + Each /dev/fw* is associated with one IEEE 1394 node, which can + be remote or local nodes. Operations on a /dev/fw* file have + different scope: + - The 1394 node which is associated with the file: + - Asynchronous request transmission + - Get the Configuration ROM + - Query node ID + - Query maximum speed of the path between this node + and local node + - The 1394 bus (i.e. "card") to which the node is attached to: + - Isochronous stream transmission and reception + - Asynchronous stream transmission and reception + - Asynchronous broadcast request transmission + - PHY packet transmission and reception + - Allocate, reallocate, deallocate isochronous + resources (channels, bandwidth) at the bus's IRM + - Query node IDs of local node, root node, IRM, bus + manager + - Query cycle time + - Bus reset initiation, bus reset event reception + - All 1394 buses: + - Allocation of IEEE 1212 address ranges on the local + link layers, reception of inbound requests to such + an address range, asynchronous response transmission + to inbound requests + - Addition of descriptors or directories to the local + nodes' Configuration ROM + + Due to the different scope of operations and in order to let + userland implement different access permission models, some + operations are restricted to /dev/fw* files that are associated + with a local node: + - Addition of descriptors or directories to the local + nodes' Configuration ROM + - PHY packet transmission and reception + + A /dev/fw* file remains associated with one particular node + during its entire life time. Bus topology changes, and hence + node ID changes, are tracked by firewire-core. ABI users do not + need to be aware of topology. + + The following file operations are supported: + + open(2) + Currently the only useful flags are O_RDWR. + + ioctl(2) + Initiate various actions. Some take immediate effect, others + are performed asynchronously while or after the ioctl returns. + See the inline documentation in <linux/firewire-cdev.h> for + descriptions of all ioctls. + + poll(2), select(2), epoll_wait(2) etc. + Watch for events to become available to be read. + + read(2) + Receive various events. There are solicited events like + outbound asynchronous transaction completion or isochronous + buffer completion, and unsolicited events such as bus resets, + request reception, or PHY packet reception. Always use a read + buffer which is large enough to receive the largest event that + could ever arrive. See <linux/firewire-cdev.h> for descriptions + of all event types and for which ioctls affect reception of + events. + + mmap(2) + Allocate a DMA buffer for isochronous reception or transmission + and map it into the process address space. The arguments should + be used as follows: addr = NULL, length = the desired buffer + size, i.e. number of packets times size of largest packet, + prot = at least PROT_READ for reception and at least PROT_WRITE + for transmission, flags = MAP_SHARED, fd = the handle to the + /dev/fw*, offset = 0. + + Isochronous reception works in packet-per-buffer fashion except + for multichannel reception which works in buffer-fill mode. + + munmap(2) + Unmap the isochronous I/O buffer from the process address space. + + close(2) + Besides stopping and freeing I/O contexts that were associated + with the file descriptor, back out any changes to the local + nodes' Configuration ROM. Deallocate isochronous channels and + bandwidth at the IRM that were marked for kernel-assisted + re- and deallocation. + +Users: libraw1394 + libdc1394 + tools like jujuutils, fwhack, ... diff --git a/Documentation/ABI/stable/sysfs-bus-firewire b/Documentation/ABI/stable/sysfs-bus-firewire new file mode 100644 index 00000000000..3d484e5dc84 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-bus-firewire @@ -0,0 +1,122 @@ +What: /sys/bus/firewire/devices/fw[0-9]+/ +Date: May 2007 +KernelVersion: 2.6.22 +Contact: linux1394-devel@lists.sourceforge.net +Description: + IEEE 1394 node device attributes. + Read-only. Mutable during the node device's lifetime. + See IEEE 1212 for semantic definitions. + + config_rom + Contents of the Configuration ROM register. + Binary attribute; an array of host-endian u32. + + guid + The node's EUI-64 in the bus information block of + Configuration ROM. + Hexadecimal string representation of an u64. + + +What: /sys/bus/firewire/devices/fw[0-9]+/units +Date: June 2009 +KernelVersion: 2.6.31 +Contact: linux1394-devel@lists.sourceforge.net +Description: + IEEE 1394 node device attribute. + Read-only. Mutable during the node device's lifetime. + See IEEE 1212 for semantic definitions. + + units + Summary of all units present in an IEEE 1394 node. + Contains space-separated tuples of specifier_id and + version of each unit present in the node. Specifier_id + and version are hexadecimal string representations of + u24 of the respective unit directory entries. + Specifier_id and version within each tuple are separated + by a colon. + +Users: udev rules to set ownership and access permissions or ACLs of + /dev/fw[0-9]+ character device files + + +What: /sys/bus/firewire/devices/fw[0-9]+[.][0-9]+/ +Date: May 2007 +KernelVersion: 2.6.22 +Contact: linux1394-devel@lists.sourceforge.net +Description: + IEEE 1394 unit device attributes. + Read-only. Immutable during the unit device's lifetime. + See IEEE 1212 for semantic definitions. + + modalias + Same as MODALIAS in the uevent at device creation. + + rom_index + Offset of the unit directory within the parent device's + (node device's) Configuration ROM, in quadlets. + Decimal string representation. + + +What: /sys/bus/firewire/devices/*/ +Date: May 2007 +KernelVersion: 2.6.22 +Contact: linux1394-devel@lists.sourceforge.net +Description: + Attributes common to IEEE 1394 node devices and unit devices. + Read-only. Mutable during the node device's lifetime. + Immutable during the unit device's lifetime. + See IEEE 1212 for semantic definitions. + + These attributes are only created if the root directory of an + IEEE 1394 node or the unit directory of an IEEE 1394 unit + actually contains according entries. + + hardware_version + Hexadecimal string representation of an u24. + + hardware_version_name + Contents of a respective textual descriptor leaf. + + model + Hexadecimal string representation of an u24. + + model_name + Contents of a respective textual descriptor leaf. + + specifier_id + Hexadecimal string representation of an u24. + Mandatory in unit directories according to IEEE 1212. + + vendor + Hexadecimal string representation of an u24. + Mandatory in the root directory according to IEEE 1212. + + vendor_name + Contents of a respective textual descriptor leaf. + + version + Hexadecimal string representation of an u24. + Mandatory in unit directories according to IEEE 1212. + + +What: /sys/bus/firewire/drivers/sbp2/fw*/host*/target*/*:*:*:*/ieee1394_id + formerly + /sys/bus/ieee1394/drivers/sbp2/fw*/host*/target*/*:*:*:*/ieee1394_id +Date: Feb 2004 +KernelVersion: 2.6.4 +Contact: linux1394-devel@lists.sourceforge.net +Description: + SCSI target port identifier and logical unit identifier of a + logical unit of an SBP-2 target. The identifiers are specified + in SAM-2...SAM-4 annex A. They are persistent and world-wide + unique properties the SBP-2 attached target. + + Read-only attribute, immutable during the target's lifetime. + Format, as exposed by firewire-sbp2 since 2.6.22, May 2007: + Colon-separated hexadecimal string representations of + u64 EUI-64 : u24 directory_ID : u16 LUN + without 0x prefixes, without whitespace. The former sbp2 driver + (removed in 2.6.37 after being superseded by firewire-sbp2) used + a somewhat shorter format which was not as close to SAM. + +Users: udev rules to create /dev/disk/by-id/ symlinks diff --git a/Documentation/ABI/stable/vdso b/Documentation/ABI/stable/vdso new file mode 100644 index 00000000000..8a1cbb59449 --- /dev/null +++ b/Documentation/ABI/stable/vdso @@ -0,0 +1,27 @@ +On some architectures, when the kernel loads any userspace program it +maps an ELF DSO into that program's address space. This DSO is called +the vDSO and it often contains useful and highly-optimized alternatives +to real syscalls. + +These functions are called just like ordinary C function according to +your platform's ABI. Call them from a sensible context. (For example, +if you set CS on x86 to something strange, the vDSO functions are +within their rights to crash.) In addition, if you pass a bad +pointer to a vDSO function, you might get SIGSEGV instead of -EFAULT. + +To find the DSO, parse the auxiliary vector passed to the program's +entry point. The AT_SYSINFO_EHDR entry will point to the vDSO. + +The vDSO uses symbol versioning; whenever you request a symbol from the +vDSO, specify the version you are expecting. + +Programs that dynamically link to glibc will use the vDSO automatically. +Otherwise, you can use the reference parser in Documentation/vDSO/parse_vdso.c. + +Unless otherwise noted, the set of symbols with any given version and the +ABI of those symbols is considered stable. It may vary across architectures, +though. + +(As of this writing, this ABI documentation as been confirmed for x86_64. + The maintainers of the other vDSO-using architectures should confirm + that it is correct for their architecture.)
\ No newline at end of file diff --git a/Documentation/ABI/testing/sysfs-driver-hid-roccat-koneplus b/Documentation/ABI/testing/sysfs-driver-hid-roccat-koneplus index c1b53b8bc2a..65e6e5dd67e 100644 --- a/Documentation/ABI/testing/sysfs-driver-hid-roccat-koneplus +++ b/Documentation/ABI/testing/sysfs-driver-hid-roccat-koneplus @@ -92,6 +92,14 @@ Description: The mouse has a tracking- and a distance-control-unit. These This file is writeonly. Users: http://roccat.sourceforge.net +What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/talk +Date: May 2011 +Contact: Stefan Achatz <erazor_de@users.sourceforge.net> +Description: Used to active some easy* functions of the mouse from outside. + The data has to be 16 bytes long. + This file is writeonly. +Users: http://roccat.sourceforge.net + What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/tcu Date: October 2010 Contact: Stefan Achatz <erazor_de@users.sourceforge.net> diff --git a/Documentation/ABI/testing/sysfs-driver-hid-wiimote b/Documentation/ABI/testing/sysfs-driver-hid-wiimote new file mode 100644 index 00000000000..5d5a16ea57c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-hid-wiimote @@ -0,0 +1,10 @@ +What: /sys/bus/hid/drivers/wiimote/<dev>/led1 +What: /sys/bus/hid/drivers/wiimote/<dev>/led2 +What: /sys/bus/hid/drivers/wiimote/<dev>/led3 +What: /sys/bus/hid/drivers/wiimote/<dev>/led4 +Date: July 2011 +KernelVersion: 3.1 +Contact: David Herrmann <dh.herrmann@googlemail.com> +Description: Make it possible to set/get current led state. Reading from it + returns 0 if led is off and 1 if it is on. Writing 0 to it + disables the led, writing 1 enables it. diff --git a/Documentation/Changes b/Documentation/Changes index 5f4828a034e..b1758088527 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -2,13 +2,7 @@ Intro ===== This document is designed to provide a list of the minimum levels of -software necessary to run the 2.6 kernels, as well as provide brief -instructions regarding any other "Gotchas" users may encounter when -trying life on the Bleeding Edge. If upgrading from a pre-2.4.x -kernel, please consult the Changes file included with 2.4.x kernels for -additional information; most of that information will not be repeated -here. Basically, this document assumes that your system is already -functional and running at least 2.4.x kernels. +software necessary to run the 3.0 kernels. This document is originally based on my "Changes" file for 2.0.x kernels and therefore owes credit to the same people as that file (Jared Mauch, @@ -22,11 +16,10 @@ Upgrade to at *least* these software revisions before thinking you've encountered a bug! If you're unsure what version you're currently running, the suggested command should tell you. -Again, keep in mind that this list assumes you are already -functionally running a Linux 2.4 kernel. Also, not all tools are -necessary on all systems; obviously, if you don't have any ISDN -hardware, for example, you probably needn't concern yourself with -isdn4k-utils. +Again, keep in mind that this list assumes you are already functionally +running a Linux kernel. Also, not all tools are necessary on all +systems; obviously, if you don't have any ISDN hardware, for example, +you probably needn't concern yourself with isdn4k-utils. o Gnu C 3.2 # gcc --version o Gnu make 3.80 # make --version @@ -114,12 +107,12 @@ Ksymoops If the unthinkable happens and your kernel oopses, you may need the ksymoops tool to decode it, but in most cases you don't. -In the 2.6 kernel it is generally preferred to build the kernel with -CONFIG_KALLSYMS so that it produces readable dumps that can be used as-is -(this also produces better output than ksymoops). -If for some reason your kernel is not build with CONFIG_KALLSYMS and -you have no way to rebuild and reproduce the Oops with that option, then -you can still decode that Oops with ksymoops. +It is generally preferred to build the kernel with CONFIG_KALLSYMS so +that it produces readable dumps that can be used as-is (this also +produces better output than ksymoops). If for some reason your kernel +is not build with CONFIG_KALLSYMS and you have no way to rebuild and +reproduce the Oops with that option, then you can still decode that Oops +with ksymoops. Module-Init-Tools ----------------- @@ -261,8 +254,8 @@ needs to be recompiled or (preferably) upgraded. NFS-utils --------- -In 2.4 and earlier kernels, the nfs server needed to know about any -client that expected to be able to access files via NFS. This +In ancient (2.4 and earlier) kernels, the nfs server needed to know +about any client that expected to be able to access files via NFS. This information would be given to the kernel by "mountd" when the client mounted the filesystem, or by "exportfs" at system startup. exportfs would take information about active clients from /var/lib/nfs/rmtab. @@ -272,11 +265,11 @@ which is not always easy, particularly when trying to implement fail-over. Even when the system is working well, rmtab suffers from getting lots of old entries that never get removed. -With 2.6 we have the option of having the kernel tell mountd when it -gets a request from an unknown host, and mountd can give appropriate -export information to the kernel. This removes the dependency on -rmtab and means that the kernel only needs to know about currently -active clients. +With modern kernels we have the option of having the kernel tell mountd +when it gets a request from an unknown host, and mountd can give +appropriate export information to the kernel. This removes the +dependency on rmtab and means that the kernel only needs to know about +currently active clients. To enable this new functionality, you need to: diff --git a/Documentation/DocBook/80211.tmpl b/Documentation/DocBook/80211.tmpl index 8906648f962..445289cd0e6 100644 --- a/Documentation/DocBook/80211.tmpl +++ b/Documentation/DocBook/80211.tmpl @@ -402,8 +402,9 @@ !Finclude/net/mac80211.h set_key_cmd !Finclude/net/mac80211.h ieee80211_key_conf !Finclude/net/mac80211.h ieee80211_key_flags -!Finclude/net/mac80211.h ieee80211_tkip_key_type -!Finclude/net/mac80211.h ieee80211_get_tkip_key +!Finclude/net/mac80211.h ieee80211_get_tkip_p1k +!Finclude/net/mac80211.h ieee80211_get_tkip_p1k_iv +!Finclude/net/mac80211.h ieee80211_get_tkip_p2k !Finclude/net/mac80211.h ieee80211_key_removed </chapter> diff --git a/Documentation/DocBook/kernel-hacking.tmpl b/Documentation/DocBook/kernel-hacking.tmpl index 7b3f4936341..07a9c48de5a 100644 --- a/Documentation/DocBook/kernel-hacking.tmpl +++ b/Documentation/DocBook/kernel-hacking.tmpl @@ -409,7 +409,7 @@ cond_resched(); /* Will sleep */ <para> You should always compile your kernel - <symbol>CONFIG_DEBUG_SPINLOCK_SLEEP</symbol> on, and it will warn + <symbol>CONFIG_DEBUG_ATOMIC_SLEEP</symbol> on, and it will warn you if you break these rules. If you <emphasis>do</emphasis> break the rules, you will eventually lock up your box. </para> diff --git a/Documentation/DocBook/writing-an-alsa-driver.tmpl b/Documentation/DocBook/writing-an-alsa-driver.tmpl index 58ced2346e6..598c22f3b3a 100644 --- a/Documentation/DocBook/writing-an-alsa-driver.tmpl +++ b/Documentation/DocBook/writing-an-alsa-driver.tmpl @@ -1164,7 +1164,7 @@ } chip->port = pci_resource_start(pci, 0); if (request_irq(pci->irq, snd_mychip_interrupt, - IRQF_SHARED, "My Chip", chip)) { + IRQF_SHARED, KBUILD_MODNAME, chip)) { printk(KERN_ERR "cannot grab irq %d\n", pci->irq); snd_mychip_free(chip); return -EBUSY; @@ -1197,7 +1197,7 @@ /* pci_driver definition */ static struct pci_driver driver = { - .name = "My Own Chip", + .name = KBUILD_MODNAME, .id_table = snd_mychip_ids, .probe = snd_mychip_probe, .remove = __devexit_p(snd_mychip_remove), @@ -1340,7 +1340,7 @@ <programlisting> <![CDATA[ if (request_irq(pci->irq, snd_mychip_interrupt, - IRQF_SHARED, "My Chip", chip)) { + IRQF_SHARED, KBUILD_MODNAME, chip)) { printk(KERN_ERR "cannot grab irq %d\n", pci->irq); snd_mychip_free(chip); return -EBUSY; @@ -1616,7 +1616,7 @@ <programlisting> <![CDATA[ static struct pci_driver driver = { - .name = "My Own Chip", + .name = KBUILD_MODNAME, .id_table = snd_mychip_ids, .probe = snd_mychip_probe, .remove = __devexit_p(snd_mychip_remove), @@ -5816,7 +5816,7 @@ struct _snd_pcm_runtime { <programlisting> <![CDATA[ static struct pci_driver driver = { - .name = "My Chip", + .name = KBUILD_MODNAME, .id_table = snd_my_ids, .probe = snd_my_probe, .remove = __devexit_p(snd_my_remove), diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist index da0382daa39..7b13be41c08 100644 --- a/Documentation/SubmitChecklist +++ b/Documentation/SubmitChecklist @@ -53,7 +53,7 @@ kernel patches. 12: Has been tested with CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES, - CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_SPINLOCK_SLEEP all simultaneously + CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_ATOMIC_SLEEP all simultaneously enabled. 13: Has been build- and runtime tested with and without CONFIG_SMP and diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting index 4e686a2ed91..a341d87d276 100644 --- a/Documentation/arm/Booting +++ b/Documentation/arm/Booting @@ -164,3 +164,8 @@ In either case, the following conditions must be met: - The boot loader is expected to call the kernel image by jumping directly to the first instruction of the kernel image. + On CPUs supporting the ARM instruction set, the entry must be + made in ARM state, even for a Thumb-2 kernel. + + On CPUs supporting only the Thumb instruction set such as + Cortex-M class CPUs, the entry must be made in Thumb state. diff --git a/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt new file mode 100644 index 00000000000..441959846e1 --- /dev/null +++ b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt @@ -0,0 +1,42 @@ +ROM-able zImage boot from eSD +----------------------------- + +An ROM-able zImage compiled with ZBOOT_ROM_SDHI may be written to eSD and +SuperH Mobile ARM will to boot directly from the SDHI hardware block. + +This is achieved by the mask ROM loading the first portion of the image into +MERAM and then jumping to it. This portion contains loader code which +copies the entire image to SDRAM and jumps to it. From there the zImage +boot code proceeds as normal, uncompressing the image into its final +location and then jumping to it. + +This code has been tested on an mackerel board using the developer 1A eSD +boot mode which is configured using the following jumper settings. + + 8 7 6 5 4 3 2 1 + x|x|x|x| |x|x| +S4 -+-+-+-+-+-+-+- + | | | |x| | |x on + +The eSD card needs to be present in SDHI slot 1 (CN7). +As such S1 and S33 also need to be configured as per +the notes in arch/arm/mach-shmobile/board-mackerel.c. + +A partial zImage must be written to physical partition #1 (boot) +of the eSD at sector 0 in vrl4 format. A utility vrl4 is supplied to +accomplish this. + +e.g. + vrl4 < zImage | dd of=/dev/sdX bs=512 count=17 + +A full copy of _the same_ zImage should be written to physical partition #1 +(boot) of the eSD at sector 0. This should _not_ be in vrl4 format. + + vrl4 < zImage | dd of=/dev/sdX bs=512 + +Note: The commands above assume that the physical partition has been +switched. No such facility currently exists in the Linux Kernel. + +Physical partitions are described in the eSD specification. At the time of +writing they are not the same as partitions that are typically configured +using fdisk and visible through /proc/partitions diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt index c12bfc1a00c..359587b2367 100644 --- a/Documentation/arm/Samsung-S3C24XX/Overview.txt +++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt @@ -8,10 +8,13 @@ Introduction The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported by the 's3c2410' architecture of ARM Linux. Currently the S3C2410, - S3C2412, S3C2413, S3C2416 S3C2440, S3C2442, S3C2443 and S3C2450 devices + S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443 and S3C2450 devices are supported. - Support for the S3C2400 and S3C24A0 series are in progress. + Support for the S3C2400 and S3C24A0 series was never completed and the + corresponding code has been removed after a while. If someone wishes to + revive this effort, partial support can be retrieved from earlier Linux + versions. The S3C2416 and S3C2450 devices are very similar and S3C2450 support is included under the arch/arm/mach-s3c2416 directory. Note, whilst core diff --git a/Documentation/arm/kernel_user_helpers.txt b/Documentation/arm/kernel_user_helpers.txt new file mode 100644 index 00000000000..a17df9f91d1 --- /dev/null +++ b/Documentation/arm/kernel_user_helpers.txt @@ -0,0 +1,267 @@ +Kernel-provided User Helpers +============================ + +These are segment of kernel provided user code reachable from user space +at a fixed address in kernel memory. This is used to provide user space +with some operations which require kernel help because of unimplemented +native feature and/or instructions in many ARM CPUs. The idea is for this +code to be executed directly in user mode for best efficiency but which is +too intimate with the kernel counter part to be left to user libraries. +In fact this code might even differ from one CPU to another depending on +the available instruction set, or whether it is a SMP systems. In other +words, the kernel reserves the right to change this code as needed without +warning. Only the entry points and their results as documented here are +guaranteed to be stable. + +This is different from (but doesn't preclude) a full blown VDSO +implementation, however a VDSO would prevent some assembly tricks with +constants that allows for efficient branching to those code segments. And +since those code segments only use a few cycles before returning to user +code, the overhead of a VDSO indirect far call would add a measurable +overhead to such minimalistic operations. + +User space is expected to bypass those helpers and implement those things +inline (either in the code emitted directly by the compiler, or part of +the implementation of a library call) when optimizing for a recent enough +processor that has the necessary native support, but only if resulting +binaries are already to be incompatible with earlier ARM processors due to +useage of similar native instructions for other things. In other words +don't make binaries unable to run on earlier processors just for the sake +of not using these kernel helpers if your compiled code is not going to +use new instructions for other purpose. + +New helpers may be added over time, so an older kernel may be missing some +helpers present in a newer kernel. For this reason, programs must check +the value of __kuser_helper_version (see below) before assuming that it is +safe to call any particular helper. This check should ideally be +performed only once at process startup time, and execution aborted early +if the required helpers are not provided by the kernel version that +process is running on. + +kuser_helper_version +-------------------- + +Location: 0xffff0ffc + +Reference declaration: + + extern int32_t __kuser_helper_version; + +Definition: + + This field contains the number of helpers being implemented by the + running kernel. User space may read this to determine the availability + of a particular helper. + +Usage example: + +#define __kuser_helper_version (*(int32_t *)0xffff0ffc) + +void check_kuser_version(void) +{ + if (__kuser_helper_version < 2) { + fprintf(stderr, "can't do atomic operations, kernel too old\n"); + abort(); + } +} + +Notes: + + User space may assume that the value of this field never changes + during the lifetime of any single process. This means that this + field can be read once during the initialisation of a library or + startup phase of a program. + +kuser_get_tls +------------- + +Location: 0xffff0fe0 + +Reference prototype: + + void * __kuser_get_tls(void); + +Input: + + lr = return address + +Output: + + r0 = TLS value + +Clobbered registers: + + none + +Definition: + + Get the TLS value as previously set via the __ARM_NR_set_tls syscall. + +Usage example: + +typedef void * (__kuser_get_tls_t)(void); +#define __kuser_get_tls (*(__kuser_get_tls_t *)0xffff0fe0) + +void foo() +{ + void *tls = __kuser_get_tls(); + printf("TLS = %p\n", tls); +} + +Notes: + + - Valid only if __kuser_helper_version >= 1 (from kernel version 2.6.12). + +kuser_cmpxchg +------------- + +Location: 0xffff0fc0 + +Reference prototype: + + int __kuser_cmpxchg(int32_t oldval, int32_t newval, volatile int32_t *ptr); + +Input: + + r0 = oldval + r1 = newval + r2 = ptr + lr = return address + +Output: + + r0 = success code (zero or non-zero) + C flag = set if r0 == 0, clear if r0 != 0 + +Clobbered registers: + + r3, ip, flags + +Definition: + + Atomically store newval in *ptr only if *ptr is equal to oldval. + Return zero if *ptr was changed or non-zero if no exchange happened. + The C flag is also set if *ptr was changed to allow for assembly + optimization in the calling code. + +Usage example: + +typedef int (__kuser_cmpxchg_t)(int oldval, int newval, volatile int *ptr); +#define __kuser_cmpxchg (*(__kuser_cmpxchg_t *)0xffff0fc0) + +int atomic_add(volatile int *ptr, int val) +{ + int old, new; + + do { + old = *ptr; + new = old + val; + } while(__kuser_cmpxchg(old, new, ptr)); + + return new; +} + +Notes: + + - This routine already includes memory barriers as needed. + + - Valid only if __kuser_helper_version >= 2 (from kernel version 2.6.12). + +kuser_memory_barrier +-------------------- + +Location: 0xffff0fa0 + +Reference prototype: + + void __kuser_memory_barrier(void); + +Input: + + lr = return address + +Output: + + none + +Clobbered registers: + + none + +Definition: + + Apply any needed memory barrier to preserve consistency with data modified + manually and __kuser_cmpxchg usage. + +Usage example: + +typedef void (__kuser_dmb_t)(void); +#define __kuser_dmb (*(__kuser_dmb_t *)0xffff0fa0) + +Notes: + + - Valid only if __kuser_helper_version >= 3 (from kernel version 2.6.15). + +kuser_cmpxchg64 +--------------- + +Location: 0xffff0f60 + +Reference prototype: + + int __kuser_cmpxchg64(const int64_t *oldval, + const int64_t *newval, + volatile int64_t *ptr); + +Input: + + r0 = pointer to oldval + r1 = pointer to newval + r2 = pointer to target value + lr = return address + +Output: + + r0 = success code (zero or non-zero) + C flag = set if r0 == 0, clear if r0 != 0 + +Clobbered registers: + + r3, lr, flags + +Definition: + + Atomically store the 64-bit value pointed by *newval in *ptr only if *ptr + is equal to the 64-bit value pointed by *oldval. Return zero if *ptr was + changed or non-zero if no exchange happened. + + The C flag is also set if *ptr was changed to allow for assembly + optimization in the calling code. + +Usage example: + +typedef int (__kuser_cmpxchg64_t)(const int64_t *oldval, + const int64_t *newval, + volatile int64_t *ptr); +#define __kuser_cmpxchg64 (*(__kuser_cmpxchg64_t *)0xffff0f60) + +int64_t atomic_add64(volatile int64_t *ptr, int64_t val) +{ + int64_t old, new; + + do { + old = *ptr; + new = old + val; + } while(__kuser_cmpxchg64(&old, &new, ptr)); + + return new; +} + +Notes: + + - This routine already includes memory barriers as needed. + + - Due to the length of this sequence, this spans 2 conventional kuser + "slots", therefore 0xffff0f80 is not used as a valid entry point. + + - Valid only if __kuser_helper_version >= 5 (from kernel version 3.1). diff --git a/Documentation/blackfin/bfin-spi-notes.txt b/Documentation/blackfin/bfin-spi-notes.txt index 556fa877f2e..eae6eaf2a09 100644 --- a/Documentation/blackfin/bfin-spi-notes.txt +++ b/Documentation/blackfin/bfin-spi-notes.txt @@ -9,6 +9,8 @@ the entire SPI transfer. - And not just bits_per_word duration. In most cases you can utilize SPI MODE_3 instead of MODE_0 to work-around this behavior. If your SPI slave device in question requires SPI MODE_0 or MODE_2 timing, you can utilize the GPIO controlled SPI Slave Select option instead. +In this case, you should use GPIO based CS for all of your slaves and not just +the ones using mode 0 or 2 in order to guarantee correct CS toggling behavior. You can even use the same pin whose peripheral role is a SSEL, but use it as a GPIO instead. diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index f65274081c8..d8147b336c3 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -45,9 +45,13 @@ device. rq_affinity (RW) ---------------- -If this option is enabled, the block layer will migrate request completions -to the CPU that originally submitted the request. For some workloads -this provides a significant reduction in CPU cycles due to caching effects. +If this option is '1', the block layer will migrate request completions to the +cpu "group" that originally submitted the request. For some workloads this +provides a significant reduction in CPU cycles due to caching effects. + +For storage configurations that need to maximize distribution of completion +processing setting this option to '2' forces the completion to run on the +requesting cpu (bypassing the "group" aggregation logic). scheduler (RW) -------------- diff --git a/Documentation/cgroups/cpuacct.txt b/Documentation/cgroups/cpuacct.txt index 9ad85df4b98..9d73cc0cadb 100644 --- a/Documentation/cgroups/cpuacct.txt +++ b/Documentation/cgroups/cpuacct.txt @@ -23,7 +23,7 @@ New accounting groups can be created under the parent group /sys/fs/cgroup. # cd /sys/fs/cgroup # mkdir g1 -# echo $$ > g1 +# echo $$ > g1/tasks The above steps create a new group g1 and move the current shell process (bash) into it. CPU time consumed by this bash and its children diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt index 5b0d78e55cc..5c51ed406d1 100644 --- a/Documentation/cgroups/cpusets.txt +++ b/Documentation/cgroups/cpusets.txt @@ -180,7 +180,7 @@ files describing that cpuset: - cpuset.sched_load_balance flag: if set, load balance within CPUs on that cpuset - cpuset.sched_relax_domain_level: the searching range when migrating tasks -In addition, the root cpuset only has the following file: +In addition, only the root cpuset has the following file: - cpuset.memory_pressure_enabled flag: compute memory_pressure? New cpusets are created using the mkdir system call or shell diff --git a/Documentation/development-process/4.Coding b/Documentation/development-process/4.Coding index f3f1a469443..83f5f5b365a 100644 --- a/Documentation/development-process/4.Coding +++ b/Documentation/development-process/4.Coding @@ -244,7 +244,7 @@ testing purposes. In particular, you should turn on: - DEBUG_SLAB can find a variety of memory allocation and use errors; it should be used on most development kernels. - - DEBUG_SPINLOCK, DEBUG_SPINLOCK_SLEEP, and DEBUG_MUTEXES will find a + - DEBUG_SPINLOCK, DEBUG_ATOMIC_SLEEP, and DEBUG_MUTEXES will find a number of common locking errors. There are quite a few other debugging options, some of which will be diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt new file mode 100644 index 00000000000..1c044eb320c --- /dev/null +++ b/Documentation/devicetree/bindings/arm/pmu.txt @@ -0,0 +1,21 @@ +* ARM Performance Monitor Units + +ARM cores often have a PMU for counting cpu and cache events like cache misses +and hits. The interface to the PMU is part of the ARM ARM. The ARM PMU +representation in the device tree should be done as under:- + +Required properties: + +- compatible : should be one of + "arm,cortex-a9-pmu" + "arm,cortex-a8-pmu" + "arm,arm1176-pmu" + "arm,arm1136-pmu" +- interrupts : 1 combined interrupt or 1 per core. + +Example: + +pmu { + compatible = "arm,cortex-a9-pmu"; + interrupts = <100 101>; +}; diff --git a/Documentation/devicetree/bindings/arm/primecell.txt b/Documentation/devicetree/bindings/arm/primecell.txt new file mode 100644 index 00000000000..1d5d7a870ec --- /dev/null +++ b/Documentation/devicetree/bindings/arm/primecell.txt @@ -0,0 +1,21 @@ +* ARM Primecell Peripherals + +ARM, Ltd. Primecell peripherals have a standard id register that can be used to +identify the peripheral type, vendor, and revision. This value can be used for +driver matching. + +Required properties: + +- compatible : should be a specific value for peripheral and "arm,primecell" + +Optional properties: + +- arm,primecell-periphid : Value to override the h/w value with + +Example: + +serial@fff36000 { + compatible = "arm,pl011", "arm,primecell"; + arm,primecell-periphid = <0x00341011>; +}; + diff --git a/Documentation/devicetree/bindings/powerpc/fsl/sec.txt b/Documentation/devicetree/bindings/crypto/fsl-sec2.txt index 2b6f2d45c45..38988ef1336 100644 --- a/Documentation/devicetree/bindings/powerpc/fsl/sec.txt +++ b/Documentation/devicetree/bindings/crypto/fsl-sec2.txt @@ -1,4 +1,4 @@ -Freescale SoC SEC Security Engines +Freescale SoC SEC Security Engines versions 2.x-3.x Required properties: diff --git a/Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt b/Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt new file mode 100644 index 00000000000..4363ae4b3c1 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt @@ -0,0 +1,22 @@ +* Freescale i.MX/MXC GPIO controller + +Required properties: +- compatible : Should be "fsl,<soc>-gpio" +- reg : Address and length of the register set for the device +- interrupts : Should be the port interrupt shared by all 32 pins, if + one number. If two numbers, the first one is the interrupt shared + by low 16 pins and the second one is for high 16 pins. +- gpio-controller : Marks the device node as a gpio controller. +- #gpio-cells : Should be two. The first cell is the pin number and + the second cell is used to specify optional parameters (currently + unused). + +Example: + +gpio0: gpio@73f84000 { + compatible = "fsl,imx51-gpio", "fsl,imx31-gpio"; + reg = <0x73f84000 0x4000>; + interrupts = <50 51>; + gpio-controller; + #gpio-cells = <2>; +}; diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index edaa84d288a..4e16ba4feab 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -4,17 +4,45 @@ Specifying GPIO information for devices 1) gpios property ----------------- -Nodes that makes use of GPIOs should define them using `gpios' property, -format of which is: <&gpio-controller1-phandle gpio1-specifier - &gpio-controller2-phandle gpio2-specifier - 0 /* holes are permitted, means no GPIO 3 */ - &gpio-controller4-phandle gpio4-specifier - ...>; +Nodes that makes use of GPIOs should specify them using one or more +properties, each containing a 'gpio-list': -Note that gpio-specifier length is controller dependent. + gpio-list ::= <single-gpio> [gpio-list] + single-gpio ::= <gpio-phandle> <gpio-specifier> + gpio-phandle : phandle to gpio controller node + gpio-specifier : Array of #gpio-cells specifying specific gpio + (controller specific) + +GPIO properties should be named "[<name>-]gpios". Exact +meaning of each gpios property must be documented in the device tree +binding for each device. + +For example, the following could be used to describe gpios pins to use +as chip select lines; with chip selects 0, 1 and 3 populated, and chip +select 2 left empty: + + gpio1: gpio1 { + gpio-controller + #gpio-cells = <2>; + }; + gpio2: gpio2 { + gpio-controller + #gpio-cells = <1>; + }; + [...] + chipsel-gpios = <&gpio1 12 0>, + <&gpio1 13 0>, + <0>, /* holes are permitted, means no GPIO 2 */ + <&gpio2 2>; + +Note that gpio-specifier length is controller dependent. In the +above example, &gpio1 uses 2 cells to specify a gpio, while &gpio2 +only uses one. gpio-specifier may encode: bank, pin position inside the bank, whether pin is open-drain and whether pin is logically inverted. +Exact meaning of each specifier cell is controller specific, and must +be documented in the device tree binding for the device. Example of the node using GPIOs: @@ -28,8 +56,8 @@ and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller. 2) gpio-controller nodes ------------------------ -Every GPIO controller node must have #gpio-cells property defined, -this information will be used to translate gpio-specifiers. +Every GPIO controller node must both an empty "gpio-controller" +property, and have #gpio-cells contain the size of the gpio-specifier. Example of two SOC GPIO banks defined as gpio-controller nodes: diff --git a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt new file mode 100644 index 00000000000..eb4b530d64e --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt @@ -0,0 +1,8 @@ +NVIDIA Tegra 2 GPIO controller + +Required properties: +- compatible : "nvidia,tegra20-gpio" +- #gpio-cells : Should be two. The first cell is the pin number and the + second cell is used to specify optional parameters: + - bit 0 specifies polarity (0 for normal, 1 for inverted) +- gpio-controller : Marks the device node as a GPIO controller. diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt new file mode 100644 index 00000000000..9841057d112 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt @@ -0,0 +1,22 @@ +* Freescale (Enhanced) Configurable Serial Peripheral Interface + (CSPI/eCSPI) for i.MX + +Required properties: +- compatible : Should be "fsl,<soc>-cspi" or "fsl,<soc>-ecspi" +- reg : Offset and length of the register set for the device +- interrupts : Should contain CSPI/eCSPI interrupt +- fsl,spi-num-chipselects : Contains the number of the chipselect +- cs-gpios : Specifies the gpio pins to be used for chipselects. + +Example: + +ecspi@70010000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "fsl,imx51-ecspi"; + reg = <0x70010000 0x4000>; + interrupts = <36>; + fsl,spi-num-chipselects = <2>; + cs-gpios = <&gpio3 24 0>, /* GPIO4_24 */ + <&gpio3 25 0>; /* GPIO4_25 */ +}; diff --git a/Documentation/devicetree/bindings/spi/spi_nvidia.txt b/Documentation/devicetree/bindings/spi/spi_nvidia.txt new file mode 100644 index 00000000000..6b9e5189669 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi_nvidia.txt @@ -0,0 +1,5 @@ +NVIDIA Tegra 2 SPI device + +Required properties: +- compatible : should be "nvidia,tegra20-spi". +- gpios : should specify GPIOs used for chipselect. diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt new file mode 100644 index 00000000000..b8b27b0aca1 --- /dev/null +++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt @@ -0,0 +1,36 @@ +* UART (Universal Asynchronous Receiver/Transmitter) + +Required properties: +- compatible : one of: + - "ns8250" + - "ns16450" + - "ns16550a" + - "ns16550" + - "ns16750" + - "ns16850" + - "nvidia,tegra20-uart" + - "ibm,qpace-nwp-serial" + - "serial" if the port type is unknown. +- reg : offset and length of the register set for the device. +- interrupts : should contain uart interrupt. +- clock-frequency : the input clock frequency for the UART. + +Optional properties: +- current-speed : the current active speed of the UART. +- reg-offset : offset to apply to the mapbase from the start of the registers. +- reg-shift : quantity to shift the register offsets by. +- reg-io-width : the size (in bytes) of the IO accesses that should be + performed on the device. There are some systems that require 32-bit + accesses to the UART (e.g. TI davinci). +- used-by-rtas : set to indicate that the port is in use by the OpenFirmware + RTAS and should not be registered. + +Example: + + uart@80230000 { + compatible = "ns8250"; + reg = <0x80230000 0x100>; + clock-frequency = <3686400>; + interrupts = <10>; + reg-shift = <2>; + }; diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 5d24fa211f0..c8616f74174 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -501,16 +501,6 @@ Who: NeilBrown <neilb@suse.de> ---------------------------- -What: cancel_rearming_delayed_work[queue]() -When: 2.6.39 - -Why: The functions have been superceded by cancel_delayed_work_sync() - quite some time ago. The conversion is trivial and there is no - in-kernel user left. -Who: Tejun Heo <tj@kernel.org> - ----------------------------- - What: Legacy, non-standard chassis intrusion detection interface. When: June 2011 Why: The adm9240, w83792d and w83793 hardware monitoring drivers have @@ -583,3 +573,25 @@ Why: Superseded by the UVCIOC_CTRL_QUERY ioctl. Who: Laurent Pinchart <laurent.pinchart@ideasonboard.com> ---------------------------- + +What: For VIDIOC_S_FREQUENCY the type field must match the device node's type. + If not, return -EINVAL. +When: 3.2 +Why: It makes no sense to switch the tuner to radio mode by calling + VIDIOC_S_FREQUENCY on a video node, or to switch the tuner to tv mode by + calling VIDIOC_S_FREQUENCY on a radio node. This is the first step of a + move to more consistent handling of tv and radio tuners. +Who: Hans Verkuil <hans.verkuil@cisco.com> + +---------------------------- + +What: Opening a radio device node will no longer automatically switch the + tuner mode from tv to radio. +When: 3.3 +Why: Just opening a V4L device should not change the state of the hardware + like that. It's very unexpected and against the V4L spec. Instead, you + switch to radio mode by calling VIDIOC_S_FREQUENCY. This is the second + and last step of the move to consistent handling of tv and radio tuners. +Who: Hans Verkuil <hans.verkuil@cisco.com> + +---------------------------- diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 57d827d6071..7e4699146fe 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -52,7 +52,7 @@ ata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); int (*permission) (struct inode *, int, unsigned int); - int (*check_acl)(struct inode *, int, unsigned int); + int (*get_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -80,7 +80,7 @@ put_link: no truncate: yes (see below) setattr: yes permission: no (may not block if called in rcu-walk mode) -check_acl: no +get_acl: no getattr: no setxattr: yes getxattr: no @@ -412,7 +412,7 @@ prototypes: int (*open) (struct inode *, struct file *); int (*flush) (struct file *); int (*release) (struct inode *, struct file *); - int (*fsync) (struct file *, int datasync); + int (*fsync) (struct file *, loff_t start, loff_t end, int datasync); int (*aio_fsync) (struct kiocb *, int datasync); int (*fasync) (int, struct file *, int); int (*lock) (struct file *, int, struct file_lock *); @@ -438,9 +438,7 @@ prototypes: locking rules: All may block except for ->setlease. - No VFS locks held on entry except for ->fsync and ->setlease. - -->fsync() has i_mutex on inode. + No VFS locks held on entry except for ->setlease. ->setlease has the file_list_lock held and must not sleep. diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt index d5c0cef38a7..873a2ab2e9f 100644 --- a/Documentation/filesystems/nilfs2.txt +++ b/Documentation/filesystems/nilfs2.txt @@ -40,7 +40,6 @@ Features which NILFS2 does not support yet: - POSIX ACLs - quotas - fsck - - resize - defragmentation Mount options diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 6e29954851a..b4a3d765ff9 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -400,10 +400,32 @@ a file off. -- [mandatory] - --- -[mandatory] ->get_sb() is gone. Switch to use of ->mount(). Typically it's just a matter of switching from calling get_sb_... to mount_... and changing the function type. If you were doing it manually, just switch from setting ->mnt_root to some pointer to returning that pointer. On errors return ERR_PTR(...). + +-- +[mandatory] + ->permission() and generic_permission()have lost flags +argument; instead of passing IPERM_FLAG_RCU we add MAY_NOT_BLOCK into mask. + generic_permission() has also lost the check_acl argument; ACL checking +has been taken to VFS and filesystems need to provide a non-NULL ->i_op->get_acl +to read an ACL from disk. + +-- +[mandatory] + If you implement your own ->llseek() you must handle SEEK_HOLE and +SEEK_DATA. You can hanle this by returning -EINVAL, but it would be nicer to +support it in some way. The generic handler assumes that the entire file is +data and there is a virtual hole at the end of the file. So if the provided +offset is less than i_size and SEEK_DATA is specified, return the same offset. +If the above is true for the offset and you are given SEEK_HOLE, return the end +of the file. If the offset is i_size or greater return -ENXIO in either case. + +[mandatory] + If you have your own ->fsync() you must make sure to call +filemap_write_and_wait_range() so that all dirty pages are synced out properly. +You must also keep in mind that ->fsync() is not called with i_mutex held +anymore, so if you require i_mutex locking you must make sure to take it and +release it yourself. diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt index 8e4fab639d9..a0a61d2f389 100644 --- a/Documentation/filesystems/ubifs.txt +++ b/Documentation/filesystems/ubifs.txt @@ -111,34 +111,6 @@ The following is an example of the kernel boot arguments to attach mtd0 to UBI and mount volume "rootfs": ubi.mtd=0 root=ubi0:rootfs rootfstype=ubifs - -Module Parameters for Debugging -=============================== - -When UBIFS has been compiled with debugging enabled, there are 2 module -parameters that are available to control aspects of testing and debugging. - -debug_chks Selects extra checks that UBIFS can do while running: - - Check Flag value - - General checks 1 - Check Tree Node Cache (TNC) 2 - Check indexing tree size 4 - Check orphan area 8 - Check old indexing tree 16 - Check LEB properties (lprops) 32 - Check leaf nodes and inodes 64 - -debug_tsts Selects a mode of testing, as follows: - - Test mode Flag value - - Failure mode for recovery testing 4 - -For example, set debug_chks to 3 to enable general and TNC checks. - - References ========== diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 88b9f5519af..52d8fb81cff 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -229,6 +229,8 @@ struct super_operations { ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); + int (*nr_cached_objects)(struct super_block *); + void (*free_cached_objects)(struct super_block *, int); }; All methods are called without any locks being held, unless otherwise @@ -301,6 +303,26 @@ or bottom half). quota_write: called by the VFS to write to filesystem quota file. + nr_cached_objects: called by the sb cache shrinking function for the + filesystem to return the number of freeable cached objects it contains. + Optional. + + free_cache_objects: called by the sb cache shrinking function for the + filesystem to scan the number of objects indicated to try to free them. + Optional, but any filesystem implementing this method needs to also + implement ->nr_cached_objects for it to be called correctly. + + We can't do anything with any errors that the filesystem might + encountered, hence the void return type. This will never be called if + the VM is trying to reclaim under GFP_NOFS conditions, hence this + method does not need to handle that situation itself. + + Implementations must include conditional reschedule calls inside any + scanning loop that is done. This allows the VFS to determine + appropriate scan batch sizes without having to worry about whether + implementations will cause holdoff problems due to large scan batch + sizes. + Whoever sets up the inode is responsible for filling in the "i_op" field. This is a pointer to a "struct inode_operations" which describes the methods that can be performed on individual inodes. @@ -333,8 +355,8 @@ struct inode_operations { void * (*follow_link) (struct dentry *, struct nameidata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int, unsigned int); - int (*check_acl)(struct inode *, int, unsigned int); + int (*permission) (struct inode *, int); + int (*get_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -423,7 +445,7 @@ otherwise noted. permission: called by the VFS to check for access rights on a POSIX-like filesystem. - May be called in rcu-walk mode (flags & IPERM_FLAG_RCU). If in rcu-walk + May be called in rcu-walk mode (mask & MAY_NOT_BLOCK). If in rcu-walk mode, the filesystem must check the permission without blocking or storing to the inode. @@ -755,7 +777,7 @@ struct file_operations { int (*open) (struct inode *, struct file *); int (*flush) (struct file *); int (*release) (struct inode *, struct file *); - int (*fsync) (struct file *, int datasync); + int (*fsync) (struct file *, loff_t, loff_t, int datasync); int (*aio_fsync) (struct kiocb *, int datasync); int (*fasync) (int, struct file *, int); int (*lock) (struct file *, int, struct file_lock *); diff --git a/Documentation/ja_JP/SubmitChecklist b/Documentation/ja_JP/SubmitChecklist index 2df4576f117..cb5507b1ac8 100644 --- a/Documentation/ja_JP/SubmitChecklist +++ b/Documentation/ja_JP/SubmitChecklist @@ -68,7 +68,7 @@ Linux 銈兗銉嶃儷銉戙儍銉佹姇绋胯呭悜銇戙儊銈с儍銈儶銈广儓 12: CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES, CONFIG_DEBUG_SPINLOCK, - CONFIG_DEBUG_SPINLOCK_SLEEP 銇撱倢銈夊叏銇︺倰鍚屾檪銇湁鍔广伀銇椼仸鍕曚綔纰鸿獚銈 + CONFIG_DEBUG_ATOMIC_SLEEP 銇撱倢銈夊叏銇︺倰鍚屾檪銇湁鍔广伀銇椼仸鍕曚綔纰鸿獚銈 琛屻仯銇︺亸銇犮仌銇勩 13: CONFIG_SMP, CONFIG_PREEMPT 銈掓湁鍔广伀銇椼仧鍫村悎銇ㄧ劇鍔广伀銇椼仧鍫村悎銇浮鏂广仹 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index aa47be71df4..40cc653984e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1159,10 +1159,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. for all guests. Default is 1 (enabled) if in 64bit or 32bit-PAE mode - kvm-intel.bypass_guest_pf= - [KVM,Intel] Disables bypassing of guest page faults - on Intel chips. Default is 1 (enabled) - kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. Default is 1 (enabled) @@ -1737,6 +1733,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page fault handling. + no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. + steal time is computed, but won't influence scheduler + behaviour + nolapic [X86-32,APIC] Do not enable or use the local APIC. nolapic_timer [X86-32,APIC] Do not use the local APIC timer. diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt index 1565eefd6fd..61815483efa 100644 --- a/Documentation/laptops/thinkpad-acpi.txt +++ b/Documentation/laptops/thinkpad-acpi.txt @@ -534,6 +534,8 @@ Events that are never propagated by the driver: 0x2404 System is waking up from hibernation to undock 0x2405 System is waking up from hibernation to eject bay 0x5010 Brightness level changed/control event +0x6000 KEYBOARD: Numlock key pressed +0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED) Events that are propagated by the driver to userspace: @@ -545,6 +547,8 @@ Events that are propagated by the driver to userspace: 0x3006 Bay hotplug request (hint to power up SATA link when the optical drive tray is ejected) 0x4003 Undocked (see 0x2x04), can sleep again +0x4010 Docked into hotplug port replicator (non-ACPI dock) +0x4011 Undocked from hotplug port replicator (non-ACPI dock) 0x500B Tablet pen inserted into its storage bay 0x500C Tablet pen removed from its storage bay 0x6011 ALARM: battery is too hot @@ -552,6 +556,7 @@ Events that are propagated by the driver to userspace: 0x6021 ALARM: a sensor is too hot 0x6022 ALARM: a sensor is extremely hot 0x6030 System thermal table changed +0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED) Battery nearly empty alarms are a last resort attempt to get the operating system to hibernate or shutdown cleanly (0x2313), or shutdown diff --git a/Documentation/mmc/00-INDEX b/Documentation/mmc/00-INDEX index 93dd7a71407..a9ba6720ffd 100644 --- a/Documentation/mmc/00-INDEX +++ b/Documentation/mmc/00-INDEX @@ -4,3 +4,5 @@ mmc-dev-attrs.txt - info on SD and MMC device attributes mmc-dev-parts.txt - info on SD and MMC device partitions +mmc-async-req.txt + - info on mmc asynchronous requests diff --git a/Documentation/mmc/mmc-async-req.txt b/Documentation/mmc/mmc-async-req.txt new file mode 100644 index 00000000000..ae1907b10e4 --- /dev/null +++ b/Documentation/mmc/mmc-async-req.txt @@ -0,0 +1,87 @@ +Rationale +========= + +How significant is the cache maintenance overhead? +It depends. Fast eMMC and multiple cache levels with speculative cache +pre-fetch makes the cache overhead relatively significant. If the DMA +preparations for the next request are done in parallel with the current +transfer, the DMA preparation overhead would not affect the MMC performance. +The intention of non-blocking (asynchronous) MMC requests is to minimize the +time between when an MMC request ends and another MMC request begins. +Using mmc_wait_for_req(), the MMC controller is idle while dma_map_sg and +dma_unmap_sg are processing. Using non-blocking MMC requests makes it +possible to prepare the caches for next job in parallel with an active +MMC request. + +MMC block driver +================ + +The mmc_blk_issue_rw_rq() in the MMC block driver is made non-blocking. +The increase in throughput is proportional to the time it takes to +prepare (major part of preparations are dma_map_sg() and dma_unmap_sg()) +a request and how fast the memory is. The faster the MMC/SD is the +more significant the prepare request time becomes. Roughly the expected +performance gain is 5% for large writes and 10% on large reads on a L2 cache +platform. In power save mode, when clocks run on a lower frequency, the DMA +preparation may cost even more. As long as these slower preparations are run +in parallel with the transfer performance won't be affected. + +Details on measurements from IOZone and mmc_test +================================================ + +https://wiki.linaro.org/WorkingGroups/Kernel/Specs/StoragePerfMMC-async-req + +MMC core API extension +====================== + +There is one new public function mmc_start_req(). +It starts a new MMC command request for a host. The function isn't +truly non-blocking. If there is an ongoing async request it waits +for completion of that request and starts the new one and returns. It +doesn't wait for the new request to complete. If there is no ongoing +request it starts the new request and returns immediately. + +MMC host extensions +=================== + +There are two optional members in the mmc_host_ops -- pre_req() and +post_req() -- that the host driver may implement in order to move work +to before and after the actual mmc_host_ops.request() function is called. +In the DMA case pre_req() may do dma_map_sg() and prepare the DMA +descriptor, and post_req() runs the dma_unmap_sg(). + +Optimize for the first request +============================== + +The first request in a series of requests can't be prepared in parallel +with the previous transfer, since there is no previous request. +The argument is_first_req in pre_req() indicates that there is no previous +request. The host driver may optimize for this scenario to minimize +the performance loss. A way to optimize for this is to split the current +request in two chunks, prepare the first chunk and start the request, +and finally prepare the second chunk and start the transfer. + +Pseudocode to handle is_first_req scenario with minimal prepare overhead: + +if (is_first_req && req->size > threshold) + /* start MMC transfer for the complete transfer size */ + mmc_start_command(MMC_CMD_TRANSFER_FULL_SIZE); + + /* + * Begin to prepare DMA while cmd is being processed by MMC. + * The first chunk of the request should take the same time + * to prepare as the "MMC process command time". + * If prepare time exceeds MMC cmd time + * the transfer is delayed, guesstimate max 4k as first chunk size. + */ + prepare_1st_chunk_for_dma(req); + /* flush pending desc to the DMAC (dmaengine.h) */ + dma_issue_pending(req->dma_desc); + + prepare_2nd_chunk_for_dma(req); + /* + * The second issue_pending should be called before MMC runs out + * of the first chunk. If the MMC runs out of the first data chunk + * before this call, the transfer is delayed. + */ + dma_issue_pending(req->dma_desc); diff --git a/Documentation/networking/ifenslave.c b/Documentation/networking/ifenslave.c index 2bac9618c34..65968fbf1e4 100644 --- a/Documentation/networking/ifenslave.c +++ b/Documentation/networking/ifenslave.c @@ -260,7 +260,7 @@ int main(int argc, char *argv[]) case 'V': opt_V++; exclusive++; break; case '?': - fprintf(stderr, usage_msg); + fprintf(stderr, "%s", usage_msg); res = 2; goto out; } @@ -268,13 +268,13 @@ int main(int argc, char *argv[]) /* options check */ if (exclusive > 1) { - fprintf(stderr, usage_msg); + fprintf(stderr, "%s", usage_msg); res = 2; goto out; } if (opt_v || opt_V) { - printf(version); + printf("%s", version); if (opt_V) { res = 0; goto out; @@ -282,14 +282,14 @@ int main(int argc, char *argv[]) } if (opt_u) { - printf(usage_msg); + printf("%s", usage_msg); res = 0; goto out; } if (opt_h) { - printf(usage_msg); - printf(help_msg); + printf("%s", usage_msg); + printf("%s", help_msg); res = 0; goto out; } @@ -309,7 +309,7 @@ int main(int argc, char *argv[]) goto out; } else { /* Just show usage */ - fprintf(stderr, usage_msg); + fprintf(stderr, "%s", usage_msg); res = 2; goto out; } @@ -320,7 +320,7 @@ int main(int argc, char *argv[]) master_ifname = *spp++; if (master_ifname == NULL) { - fprintf(stderr, usage_msg); + fprintf(stderr, "%s", usage_msg); res = 2; goto out; } @@ -339,7 +339,7 @@ int main(int argc, char *argv[]) if (slave_ifname == NULL) { if (opt_d || opt_c) { - fprintf(stderr, usage_msg); + fprintf(stderr, "%s", usage_msg); res = 2; goto out; } diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index d3d653a5f9b..db2a4067013 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -106,16 +106,6 @@ inet_peer_maxttl - INTEGER when the number of entries in the pool is very small). Measured in seconds. -inet_peer_gc_mintime - INTEGER - Minimum interval between garbage collection passes. This interval is - in effect under high memory pressure on the pool. - Measured in seconds. - -inet_peer_gc_maxtime - INTEGER - Minimum interval between garbage collection passes. This interval is - in effect under low (or absent) memory pressure on the pool. - Measured in seconds. - TCP variables: somaxconn - INTEGER @@ -346,7 +336,7 @@ tcp_orphan_retries - INTEGER when RTO retransmissions remain unacknowledged. See tcp_retries2 for more details. - The default value is 7. + The default value is 8. If your machine is a loaded WEB server, you should think about lowering this value, such sockets may consume significant resources. Cf. tcp_max_orphans. @@ -394,7 +384,7 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max min: Minimal size of receive buffer used by TCP sockets. It is guaranteed to each TCP socket, even under moderate memory pressure. - Default: 8K + Default: 1 page default: initial size of receive buffer used by TCP sockets. This value overrides net.core.rmem_default used by other protocols. @@ -483,7 +473,7 @@ tcp_window_scaling - BOOLEAN tcp_wmem - vector of 3 INTEGERs: min, default, max min: Amount of memory reserved for send buffers for TCP sockets. Each TCP socket has rights to use it due to fact of its birth. - Default: 4K + Default: 1 page default: initial size of send buffer used by TCP sockets. This value overrides net.core.wmem_default used by other protocols. @@ -553,13 +543,13 @@ udp_rmem_min - INTEGER Minimal size of receive buffer used by UDP sockets in moderation. Each UDP socket is able to use the size for receiving data, even if total pages of UDP sockets exceed udp_mem pressure. The unit is byte. - Default: 4096 + Default: 1 page udp_wmem_min - INTEGER Minimal size of send buffer used by UDP sockets in moderation. Each UDP socket is able to use the size for sending data, even if total pages of UDP sockets exceed udp_mem pressure. The unit is byte. - Default: 4096 + Default: 1 page CIPSOv4 Variables: @@ -1465,10 +1455,17 @@ sctp_mem - vector of 3 INTEGERs: min, pressure, max Default is calculated at boot time from amount of available memory. sctp_rmem - vector of 3 INTEGERs: min, default, max - See tcp_rmem for a description. + Only the first value ("min") is used, "default" and "max" are + ignored. + + min: Minimal size of receive buffer used by SCTP socket. + It is guaranteed to each SCTP socket (but not association) even + under moderate memory pressure. + + Default: 1 page sctp_wmem - vector of 3 INTEGERs: min, default, max - See tcp_wmem for a description. + Currently this tunable has no effect. addr_scope_policy - INTEGER Control IPv4 address scoping - draft-stewart-tsvwg-sctp-ipv4-00 diff --git a/Documentation/networking/netdev-features.txt b/Documentation/networking/netdev-features.txt new file mode 100644 index 00000000000..4b1c0dcef84 --- /dev/null +++ b/Documentation/networking/netdev-features.txt @@ -0,0 +1,154 @@ +Netdev features mess and how to get out from it alive +===================================================== + +Author: + Micha艂 Miros艂aw <mirq-linux@rere.qmqm.pl> + + + + Part I: Feature sets +====================== + +Long gone are the days when a network card would just take and give packets +verbatim. Today's devices add multiple features and bugs (read: offloads) +that relieve an OS of various tasks like generating and checking checksums, +splitting packets, classifying them. Those capabilities and their state +are commonly referred to as netdev features in Linux kernel world. + +There are currently three sets of features relevant to the driver, and +one used internally by network core: + + 1. netdev->hw_features set contains features whose state may possibly + be changed (enabled or disabled) for a particular device by user's + request. This set should be initialized in ndo_init callback and not + changed later. + + 2. netdev->features set contains features which are currently enabled + for a device. This should be changed only by network core or in + error paths of ndo_set_features callback. + + 3. netdev->vlan_features set contains features whose state is inherited + by child VLAN devices (limits netdev->features set). This is currently + used for all VLAN devices whether tags are stripped or inserted in + hardware or software. + + 4. netdev->wanted_features set contains feature set requested by user. + This set is filtered by ndo_fix_features callback whenever it or + some device-specific conditions change. This set is internal to + networking core and should not be referenced in drivers. + + + + Part II: Controlling enabled features +======================================= + +When current feature set (netdev->features) is to be changed, new set +is calculated and filtered by calling ndo_fix_features callback +and netdev_fix_features(). If the resulting set differs from current +set, it is passed to ndo_set_features callback and (if the callback +returns success) replaces value stored in netdev->features. +NETDEV_FEAT_CHANGE notification is issued after that whenever current +set might have changed. + +The following events trigger recalculation: + 1. device's registration, after ndo_init returned success + 2. user requested changes in features state + 3. netdev_update_features() is called + +ndo_*_features callbacks are called with rtnl_lock held. Missing callbacks +are treated as always returning success. + +A driver that wants to trigger recalculation must do so by calling +netdev_update_features() while holding rtnl_lock. This should not be done +from ndo_*_features callbacks. netdev->features should not be modified by +driver except by means of ndo_fix_features callback. + + + + Part III: Implementation hints +================================ + + * ndo_fix_features: + +All dependencies between features should be resolved here. The resulting +set can be reduced further by networking core imposed limitations (as coded +in netdev_fix_features()). For this reason it is safer to disable a feature +when its dependencies are not met instead of forcing the dependency on. + +This callback should not modify hardware nor driver state (should be +stateless). It can be called multiple times between successive +ndo_set_features calls. + +Callback must not alter features contained in NETIF_F_SOFT_FEATURES or +NETIF_F_NEVER_CHANGE sets. The exception is NETIF_F_VLAN_CHALLENGED but +care must be taken as the change won't affect already configured VLANs. + + * ndo_set_features: + +Hardware should be reconfigured to match passed feature set. The set +should not be altered unless some error condition happens that can't +be reliably detected in ndo_fix_features. In this case, the callback +should update netdev->features to match resulting hardware state. +Errors returned are not (and cannot be) propagated anywhere except dmesg. +(Note: successful return is zero, >0 means silent error.) + + + + Part IV: Features +=================== + +For current list of features, see include/linux/netdev_features.h. +This section describes semantics of some of them. + + * Transmit checksumming + +For complete description, see comments near the top of include/linux/skbuff.h. + +Note: NETIF_F_HW_CSUM is a superset of NETIF_F_IP_CSUM + NETIF_F_IPV6_CSUM. +It means that device can fill TCP/UDP-like checksum anywhere in the packets +whatever headers there might be. + + * Transmit TCP segmentation offload + +NETIF_F_TSO_ECN means that hardware can properly split packets with CWR bit +set, be it TCPv4 (when NETIF_F_TSO is enabled) or TCPv6 (NETIF_F_TSO6). + + * Transmit DMA from high memory + +On platforms where this is relevant, NETIF_F_HIGHDMA signals that +ndo_start_xmit can handle skbs with frags in high memory. + + * Transmit scatter-gather + +Those features say that ndo_start_xmit can handle fragmented skbs: +NETIF_F_SG --- paged skbs (skb_shinfo()->frags), NETIF_F_FRAGLIST --- +chained skbs (skb->next/prev list). + + * Software features + +Features contained in NETIF_F_SOFT_FEATURES are features of networking +stack. Driver should not change behaviour based on them. + + * LLTX driver (deprecated for hardware drivers) + +NETIF_F_LLTX should be set in drivers that implement their own locking in +transmit path or don't need locking at all (e.g. software tunnels). +In ndo_start_xmit, it is recommended to use a try_lock and return +NETDEV_TX_LOCKED when the spin lock fails. The locking should also properly +protect against other callbacks (the rules you need to find out). + +Don't use it for new drivers. + + * netns-local device + +NETIF_F_NETNS_LOCAL is set for devices that are not allowed to move between +network namespaces (e.g. loopback). + +Don't use it in drivers. + + * VLAN challenged + +NETIF_F_VLAN_CHALLENGED should be set for devices which can't cope with VLAN +headers. Some drivers set this because the cards can't handle the bigger MTU. +[FIXME: Those cases could be fixed in VLAN code by allowing only reduced-MTU +VLANs. This may be not useful, though.] diff --git a/Documentation/networking/nfc.txt b/Documentation/networking/nfc.txt new file mode 100644 index 00000000000..b24c29bdae2 --- /dev/null +++ b/Documentation/networking/nfc.txt @@ -0,0 +1,128 @@ +Linux NFC subsystem +=================== + +The Near Field Communication (NFC) subsystem is required to standardize the +NFC device drivers development and to create an unified userspace interface. + +This document covers the architecture overview, the device driver interface +description and the userspace interface description. + +Architecture overview +--------------------- + +The NFC subsystem is responsible for: + - NFC adapters management; + - Polling for targets; + - Low-level data exchange; + +The subsystem is divided in some parts. The 'core' is responsible for +providing the device driver interface. On the other side, it is also +responsible for providing an interface to control operations and low-level +data exchange. + +The control operations are available to userspace via generic netlink. + +The low-level data exchange interface is provided by the new socket family +PF_NFC. The NFC_SOCKPROTO_RAW performs raw communication with NFC targets. + + + +--------------------------------------+ + | USER SPACE | + +--------------------------------------+ + ^ ^ + | low-level | control + | data exchange | operations + | | + | v + | +-----------+ + | AF_NFC | netlink | + | socket +-----------+ + | raw ^ + | | + v v + +---------+ +-----------+ + | rawsock | <--------> | core | + +---------+ +-----------+ + ^ + | + v + +-----------+ + | driver | + +-----------+ + +Device Driver Interface +----------------------- + +When registering on the NFC subsystem, the device driver must inform the core +of the set of supported NFC protocols and the set of ops callbacks. The ops +callbacks that must be implemented are the following: + +* start_poll - setup the device to poll for targets +* stop_poll - stop on progress polling operation +* activate_target - select and initialize one of the targets found +* deactivate_target - deselect and deinitialize the selected target +* data_exchange - send data and receive the response (transceive operation) + +Userspace interface +-------------------- + +The userspace interface is divided in control operations and low-level data +exchange operation. + +CONTROL OPERATIONS: + +Generic netlink is used to implement the interface to the control operations. +The operations are composed by commands and events, all listed below: + +* NFC_CMD_GET_DEVICE - get specific device info or dump the device list +* NFC_CMD_START_POLL - setup a specific device to polling for targets +* NFC_CMD_STOP_POLL - stop the polling operation in a specific device +* NFC_CMD_GET_TARGET - dump the list of targets found by a specific device + +* NFC_EVENT_DEVICE_ADDED - reports an NFC device addition +* NFC_EVENT_DEVICE_REMOVED - reports an NFC device removal +* NFC_EVENT_TARGETS_FOUND - reports START_POLL results when 1 or more targets +are found + +The user must call START_POLL to poll for NFC targets, passing the desired NFC +protocols through NFC_ATTR_PROTOCOLS attribute. The device remains in polling +state until it finds any target. However, the user can stop the polling +operation by calling STOP_POLL command. In this case, it will be checked if +the requester of STOP_POLL is the same of START_POLL. + +If the polling operation finds one or more targets, the event TARGETS_FOUND is +sent (including the device id). The user must call GET_TARGET to get the list of +all targets found by such device. Each reply message has target attributes with +relevant information such as the supported NFC protocols. + +All polling operations requested through one netlink socket are stopped when +it's closed. + +LOW-LEVEL DATA EXCHANGE: + +The userspace must use PF_NFC sockets to perform any data communication with +targets. All NFC sockets use AF_NFC: + +struct sockaddr_nfc { + sa_family_t sa_family; + __u32 dev_idx; + __u32 target_idx; + __u32 nfc_protocol; +}; + +To establish a connection with one target, the user must create an +NFC_SOCKPROTO_RAW socket and call the 'connect' syscall with the sockaddr_nfc +struct correctly filled. All information comes from NFC_EVENT_TARGETS_FOUND +netlink event. As a target can support more than one NFC protocol, the user +must inform which protocol it wants to use. + +Internally, 'connect' will result in an activate_target call to the driver. +When the socket is closed, the target is deactivated. + +The data format exchanged through the sockets is NFC protocol dependent. For +instance, when communicating with MIFARE tags, the data exchanged are MIFARE +commands and their responses. + +The first received package is the response to the first sent package and so +on. In order to allow valid "empty" responses, every data received has a NULL +header of 1 byte. diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt index 80a7a345490..57a24108b84 100644 --- a/Documentation/networking/stmmac.txt +++ b/Documentation/networking/stmmac.txt @@ -7,7 +7,7 @@ This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers (Synopsys IP blocks); it has been fully tested on STLinux platforms. Currently this network device driver is for all STM embedded MAC/GMAC -(7xxx SoCs). Other platforms start using it i.e. ARM SPEAr. +(i.e. 7xxx/5xxx SoCs) and it's known working on other platforms i.e. ARM SPEAr. DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100 Universal version 4.0 have been used for developing the first code @@ -71,7 +71,7 @@ Several performance tests on STM platforms showed this optimisation allows to sp the CPU while having the maximum throughput. 4.4) WOL -Wake up on Lan feature through Magic Frame is only supported for the GMAC +Wake up on Lan feature through Magic and Unicast frames are supported for the GMAC core. 4.5) DMA descriptors @@ -91,11 +91,15 @@ LRO is not supported. The driver is compatible with PAL to work with PHY and GPHY devices. 4.9) Platform information -Several information came from the platform; please refer to the -driver's Header file in include/linux directory. +Several driver's information can be passed through the platform +These are included in the include/linux/stmmac.h header file +and detailed below as well: -struct plat_stmmacenet_data { + struct plat_stmmacenet_data { int bus_id; + int phy_addr; + int interface; + struct stmmac_mdio_bus_data *mdio_bus_data; int pbl; int clk_csr; int has_gmac; @@ -103,67 +107,135 @@ struct plat_stmmacenet_data { int tx_coe; int bugged_jumbo; int pmt; - void (*fix_mac_speed)(void *priv, unsigned int speed); - void (*bus_setup)(unsigned long ioaddr); -#ifdef CONFIG_STM_DRIVERS - struct stm_pad_config *pad_config; -#endif - void *bsp_priv; -}; + int force_sf_dma_mode; + void (*fix_mac_speed)(void *priv, unsigned int speed); + void (*bus_setup)(void __iomem *ioaddr); + int (*init)(struct platform_device *pdev); + void (*exit)(struct platform_device *pdev); + void *bsp_priv; + }; Where: -- pbl (Programmable Burst Length) is maximum number of - beats to be transferred in one DMA transaction. - GMAC also enables the 4xPBL by default. -- fix_mac_speed and bus_setup are used to configure internal target - registers (on STM platforms); -- has_gmac: GMAC core is on board (get it at run-time in the next step); -- bus_id: bus identifier. -- tx_coe: core is able to perform the tx csum in HW. -- enh_desc: if sets the MAC will use the enhanced descriptor structure. -- clk_csr: CSR Clock range selection. -- bugged_jumbo: some HWs are not able to perform the csum in HW for - over-sized frames due to limited buffer sizes. Setting this - flag the csum will be done in SW on JUMBO frames. - -struct plat_stmmacphy_data { - int bus_id; - int phy_addr; - unsigned int phy_mask; - int interface; - int (*phy_reset)(void *priv); - void *priv; -}; + o bus_id: bus identifier. + o phy_addr: the physical address can be passed from the platform. + If it is set to -1 the driver will automatically + detect it at run-time by probing all the 32 addresses. + o interface: PHY device's interface. + o mdio_bus_data: specific platform fields for the MDIO bus. + o pbl: the Programmable Burst Length is maximum number of beats to + be transferred in one DMA transaction. + GMAC also enables the 4xPBL by default. + o clk_csr: CSR Clock range selection. + o has_gmac: uses the GMAC core. + o enh_desc: if sets the MAC will use the enhanced descriptor structure. + o tx_coe: core is able to perform the tx csum in HW. + o bugged_jumbo: some HWs are not able to perform the csum in HW for + over-sized frames due to limited buffer sizes. + Setting this flag the csum will be done in SW on + JUMBO frames. + o pmt: core has the embedded power module (optional). + o force_sf_dma_mode: force DMA to use the Store and Forward mode + instead of the Threshold. + o fix_mac_speed: this callback is used for modifying some syscfg registers + (on ST SoCs) according to the link speed negotiated by the + physical layer . + o bus_setup: perform HW setup of the bus. For example, on some ST platforms + this field is used to configure the AMBA bridge to generate more + efficient STBus traffic. + o init/exit: callbacks used for calling a custom initialisation; + this is sometime necessary on some platforms (e.g. ST boxes) + where the HW needs to have set some PIO lines or system cfg + registers. + o custom_cfg: this is a custom configuration that can be passed while + initialising the resources. + +The we have: + + struct stmmac_mdio_bus_data { + int bus_id; + int (*phy_reset)(void *priv); + unsigned int phy_mask; + int *irqs; + int probed_phy_irq; + }; Where: -- bus_id: bus identifier; -- phy_addr: physical address used for the attached phy device; - set it to -1 to get it at run-time; -- interface: physical MII interface mode; -- phy_reset: hook to reset HW function. - -SOURCES: -- Kconfig -- Makefile -- stmmac_main.c: main network device driver; -- stmmac_mdio.c: mdio functions; -- stmmac_ethtool.c: ethtool support; -- stmmac_timer.[ch]: timer code used for mitigating the driver dma interrupts - Only tested on ST40 platforms based. -- stmmac.h: private driver structure; -- common.h: common definitions and VFTs; -- descs.h: descriptor structure definitions; -- dwmac1000_core.c: GMAC core functions; -- dwmac1000_dma.c: dma functions for the GMAC chip; -- dwmac1000.h: specific header file for the GMAC; -- dwmac100_core: MAC 100 core and dma code; -- dwmac100_dma.c: dma funtions for the MAC chip; -- dwmac1000.h: specific header file for the MAC; -- dwmac_lib.c: generic DMA functions shared among chips -- enh_desc.c: functions for handling enhanced descriptors -- norm_desc.c: functions for handling normal descriptors - -TODO: -- XGMAC controller is not supported. -- Review the timer optimisation code to use an embedded device that seems to be + o bus_id: bus identifier; + o phy_reset: hook to reset the phy device attached to the bus. + o phy_mask: phy mask passed when register the MDIO bus within the driver. + o irqs: list of IRQs, one per PHY. + o probed_phy_irq: if irqs is NULL, use this for probed PHY. + +Below an example how the structures above are using on ST platforms. + + static struct plat_stmmacenet_data stxYYY_ethernet_platform_data = { + .pbl = 32, + .has_gmac = 0, + .enh_desc = 0, + .fix_mac_speed = stxYYY_ethernet_fix_mac_speed, + | + |-> to write an internal syscfg + | on this platform when the + | link speed changes from 10 to + | 100 and viceversa + .init = &stmmac_claim_resource, + | + |-> On ST SoC this calls own "PAD" + | manager framework to claim + | all the resources necessary + | (GPIO ...). The .custom_cfg field + | is used to pass a custom config. +}; + +Below the usage of the stmmac_mdio_bus_data: on this SoC, in fact, +there are two MAC cores: one MAC is for MDIO Bus/PHY emulation +with fixed_link support. + +static struct stmmac_mdio_bus_data stmmac1_mdio_bus = { + .bus_id = 1, + | + |-> phy device on the bus_id 1 + .phy_reset = phy_reset; + | + |-> function to provide the phy_reset on this board + .phy_mask = 0, +}; + +static struct fixed_phy_status stmmac0_fixed_phy_status = { + .link = 1, + .speed = 100, + .duplex = 1, +}; + +During the board's device_init we can configure the first +MAC for fixed_link by calling: + fixed_phy_add(PHY_POLL, 1, &stmmac0_fixed_phy_status));) +and the second one, with a real PHY device attached to the bus, +by using the stmmac_mdio_bus_data structure (to provide the id, the +reset procedure etc). + +4.10) List of source files: + o Kconfig + o Makefile + o stmmac_main.c: main network device driver; + o stmmac_mdio.c: mdio functions; + o stmmac_ethtool.c: ethtool support; + o stmmac_timer.[ch]: timer code used for mitigating the driver dma interrupts + Only tested on ST40 platforms based. + o stmmac.h: private driver structure; + o common.h: common definitions and VFTs; + o descs.h: descriptor structure definitions; + o dwmac1000_core.c: GMAC core functions; + o dwmac1000_dma.c: dma functions for the GMAC chip; + o dwmac1000.h: specific header file for the GMAC; + o dwmac100_core: MAC 100 core and dma code; + o dwmac100_dma.c: dma funtions for the MAC chip; + o dwmac1000.h: specific header file for the MAC; + o dwmac_lib.c: generic DMA functions shared among chips + o enh_desc.c: functions for handling enhanced descriptors + o norm_desc.c: functions for handling normal descriptors + +5) TODO: + o XGMAC is not supported. + o Review the timer optimisation code to use an embedded device that will be available in new chip generations. diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 64565aac6e4..3384d5996be 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -506,8 +506,8 @@ routines. Nevertheless, different callback pointers are used in case there is a situation where it actually matters. -Device Power Domains --------------------- +Device Power Management Domains +------------------------------- Sometimes devices share reference clocks or other power resources. In those cases it generally is not possible to put devices into low-power states individually. Instead, a set of devices sharing a power resource can be put @@ -516,8 +516,8 @@ power resource. Of course, they also need to be put into the full-power state together, by turning the shared power resource on. A set of devices with this property is often referred to as a power domain. -Support for power domains is provided through the pwr_domain field of struct -device. This field is a pointer to an object of type struct dev_power_domain, +Support for power domains is provided through the pm_domain field of struct +device. This field is a pointer to an object of type struct dev_pm_domain, defined in include/linux/pm.h, providing a set of power management callbacks analogous to the subsystem-level and device driver callbacks that are executed for the given device during all power transitions, instead of the respective @@ -604,7 +604,7 @@ state temporarily, for example so that its system wakeup capability can be disabled. This all depends on the hardware and the design of the subsystem and device driver in question. -During system-wide resume from a sleep state it's best to put devices into the -full-power state, as explained in Documentation/power/runtime_pm.txt. Refer to -that document for more information regarding this particular issue as well as +During system-wide resume from a sleep state it's easiest to put devices into +the full-power state, as explained in Documentation/power/runtime_pm.txt. Refer +to that document for more information regarding this particular issue as well as for information on the device runtime power management framework in general. diff --git a/Documentation/power/opp.txt b/Documentation/power/opp.txt index 5ae70a12c1e..3035d00757a 100644 --- a/Documentation/power/opp.txt +++ b/Documentation/power/opp.txt @@ -321,6 +321,8 @@ opp_init_cpufreq_table - cpufreq framework typically is initialized with addition to CONFIG_PM as power management feature is required to dynamically scale voltage and frequency in a system. +opp_free_cpufreq_table - Free up the table allocated by opp_init_cpufreq_table + 7. Data Structures ================== Typically an SoC contains multiple voltage domains which are variable. Each diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index b24875b1ced..14dd3c6ad97 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -1,39 +1,39 @@ -Run-time Power Management Framework for I/O Devices +Runtime Power Management Framework for I/O Devices (C) 2009-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. (C) 2010 Alan Stern <stern@rowland.harvard.edu> 1. Introduction -Support for run-time power management (run-time PM) of I/O devices is provided +Support for runtime power management (runtime PM) of I/O devices is provided at the power management core (PM core) level by means of: * The power management workqueue pm_wq in which bus types and device drivers can put their PM-related work items. It is strongly recommended that pm_wq be - used for queuing all work items related to run-time PM, because this allows + used for queuing all work items related to runtime PM, because this allows them to be synchronized with system-wide power transitions (suspend to RAM, hibernation and resume from system sleep states). pm_wq is declared in include/linux/pm_runtime.h and defined in kernel/power/main.c. -* A number of run-time PM fields in the 'power' member of 'struct device' (which +* A number of runtime PM fields in the 'power' member of 'struct device' (which is of the type 'struct dev_pm_info', defined in include/linux/pm.h) that can - be used for synchronizing run-time PM operations with one another. + be used for synchronizing runtime PM operations with one another. -* Three device run-time PM callbacks in 'struct dev_pm_ops' (defined in +* Three device runtime PM callbacks in 'struct dev_pm_ops' (defined in include/linux/pm.h). * A set of helper functions defined in drivers/base/power/runtime.c that can be - used for carrying out run-time PM operations in such a way that the + used for carrying out runtime PM operations in such a way that the synchronization between them is taken care of by the PM core. Bus types and device drivers are encouraged to use these functions. -The run-time PM callbacks present in 'struct dev_pm_ops', the device run-time PM +The runtime PM callbacks present in 'struct dev_pm_ops', the device runtime PM fields of 'struct dev_pm_info' and the core helper functions provided for -run-time PM are described below. +runtime PM are described below. -2. Device Run-time PM Callbacks +2. Device Runtime PM Callbacks -There are three device run-time PM callbacks defined in 'struct dev_pm_ops': +There are three device runtime PM callbacks defined in 'struct dev_pm_ops': struct dev_pm_ops { ... @@ -72,11 +72,11 @@ knows what to do to handle the device). not mean that the device has been put into a low power state. It is supposed to mean, however, that the device will not process data and will not communicate with the CPU(s) and RAM until the subsystem-level resume - callback is executed for it. The run-time PM status of a device after + callback is executed for it. The runtime PM status of a device after successful execution of the subsystem-level suspend callback is 'suspended'. * If the subsystem-level suspend callback returns -EBUSY or -EAGAIN, - the device's run-time PM status is 'active', which means that the device + the device's runtime PM status is 'active', which means that the device _must_ be fully operational afterwards. * If the subsystem-level suspend callback returns an error code different @@ -104,7 +104,7 @@ the device). * Once the subsystem-level resume callback has completed successfully, the PM core regards the device as fully operational, which means that the device - _must_ be able to complete I/O operations as needed. The run-time PM status + _must_ be able to complete I/O operations as needed. The runtime PM status of the device is then 'active'. * If the subsystem-level resume callback returns an error code, the PM core @@ -130,7 +130,7 @@ device in that case. The value returned by this callback is ignored by the PM core. The helper functions provided by the PM core, described in Section 4, guarantee -that the following constraints are met with respect to the bus type's run-time +that the following constraints are met with respect to the bus type's runtime PM callbacks: (1) The callbacks are mutually exclusive (e.g. it is forbidden to execute @@ -142,7 +142,7 @@ PM callbacks: (2) ->runtime_idle() and ->runtime_suspend() can only be executed for 'active' devices (i.e. the PM core will only execute ->runtime_idle() or - ->runtime_suspend() for the devices the run-time PM status of which is + ->runtime_suspend() for the devices the runtime PM status of which is 'active'). (3) ->runtime_idle() and ->runtime_suspend() can only be executed for a device @@ -151,7 +151,7 @@ PM callbacks: flag of which is set. (4) ->runtime_resume() can only be executed for 'suspended' devices (i.e. the - PM core will only execute ->runtime_resume() for the devices the run-time + PM core will only execute ->runtime_resume() for the devices the runtime PM status of which is 'suspended'). Additionally, the helper functions provided by the PM core obey the following @@ -171,9 +171,9 @@ rules: scheduled requests to execute the other callbacks for the same device, except for scheduled autosuspends. -3. Run-time PM Device Fields +3. Runtime PM Device Fields -The following device run-time PM fields are present in 'struct dev_pm_info', as +The following device runtime PM fields are present in 'struct dev_pm_info', as defined in include/linux/pm.h: struct timer_list suspend_timer; @@ -205,7 +205,7 @@ defined in include/linux/pm.h: unsigned int disable_depth; - used for disabling the helper funcions (they work normally if this is - equal to zero); the initial value of it is 1 (i.e. run-time PM is + equal to zero); the initial value of it is 1 (i.e. runtime PM is initially disabled for all devices) unsigned int runtime_error; @@ -229,10 +229,10 @@ defined in include/linux/pm.h: suspend to complete; means "start a resume as soon as you've suspended" unsigned int run_wake; - - set if the device is capable of generating run-time wake-up events + - set if the device is capable of generating runtime wake-up events enum rpm_status runtime_status; - - the run-time PM status of the device; this field's initial value is + - the runtime PM status of the device; this field's initial value is RPM_SUSPENDED, which means that each device is initially regarded by the PM core as 'suspended', regardless of its real hardware status @@ -243,7 +243,7 @@ defined in include/linux/pm.h: and pm_runtime_forbid() helper functions unsigned int no_callbacks; - - indicates that the device does not use the run-time PM callbacks (see + - indicates that the device does not use the runtime PM callbacks (see Section 8); it may be modified only by the pm_runtime_no_callbacks() helper function @@ -270,16 +270,16 @@ defined in include/linux/pm.h: All of the above fields are members of the 'power' member of 'struct device'. -4. Run-time PM Device Helper Functions +4. Runtime PM Device Helper Functions -The following run-time PM helper functions are defined in +The following runtime PM helper functions are defined in drivers/base/power/runtime.c and include/linux/pm_runtime.h: void pm_runtime_init(struct device *dev); - - initialize the device run-time PM fields in 'struct dev_pm_info' + - initialize the device runtime PM fields in 'struct dev_pm_info' void pm_runtime_remove(struct device *dev); - - make sure that the run-time PM of the device will be disabled after + - make sure that the runtime PM of the device will be disabled after removing the device from device hierarchy int pm_runtime_idle(struct device *dev); @@ -289,9 +289,10 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: int pm_runtime_suspend(struct device *dev); - execute the subsystem-level suspend callback for the device; returns 0 on - success, 1 if the device's run-time PM status was already 'suspended', or + success, 1 if the device's runtime PM status was already 'suspended', or error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt - to suspend the device again in future + to suspend the device again in future and -EACCES means that + 'power.disable_depth' is different from 0 int pm_runtime_autosuspend(struct device *dev); - same as pm_runtime_suspend() except that the autosuspend delay is taken @@ -301,10 +302,11 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: int pm_runtime_resume(struct device *dev); - execute the subsystem-level resume callback for the device; returns 0 on - success, 1 if the device's run-time PM status was already 'active' or + success, 1 if the device's runtime PM status was already 'active' or error code on failure, where -EAGAIN means it may be safe to attempt to resume the device again in future, but 'power.runtime_error' should be - checked additionally + checked additionally, and -EACCES means that 'power.disable_depth' is + different from 0 int pm_request_idle(struct device *dev); - submit a request to execute the subsystem-level idle callback for the @@ -321,7 +323,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: device in future, where 'delay' is the time to wait before queuing up a suspend work item in pm_wq, in milliseconds (if 'delay' is zero, the work item is queued up immediately); returns 0 on success, 1 if the device's PM - run-time status was already 'suspended', or error code if the request + runtime status was already 'suspended', or error code if the request hasn't been scheduled (or queued up if 'delay' is 0); if the execution of ->runtime_suspend() is already scheduled and not yet expired, the new value of 'delay' will be used as the time to wait @@ -329,7 +331,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: int pm_request_resume(struct device *dev); - submit a request to execute the subsystem-level resume callback for the device (the request is represented by a work item in pm_wq); returns 0 on - success, 1 if the device's run-time PM status was already 'active', or + success, 1 if the device's runtime PM status was already 'active', or error code if the request hasn't been queued up void pm_runtime_get_noresume(struct device *dev); @@ -367,22 +369,32 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: pm_runtime_autosuspend(dev) and return its result void pm_runtime_enable(struct device *dev); - - enable the run-time PM helper functions to run the device bus type's - run-time PM callbacks described in Section 2 + - decrement the device's 'power.disable_depth' field; if that field is equal + to zero, the runtime PM helper functions can execute subsystem-level + callbacks described in Section 2 for the device int pm_runtime_disable(struct device *dev); - - prevent the run-time PM helper functions from running subsystem-level - run-time PM callbacks for the device, make sure that all of the pending - run-time PM operations on the device are either completed or canceled; + - increment the device's 'power.disable_depth' field (if the value of that + field was previously zero, this prevents subsystem-level runtime PM + callbacks from being run for the device), make sure that all of the pending + runtime PM operations on the device are either completed or canceled; returns 1 if there was a resume request pending and it was necessary to execute the subsystem-level resume callback for the device to satisfy that request, otherwise 0 is returned + int pm_runtime_barrier(struct device *dev); + - check if there's a resume request pending for the device and resume it + (synchronously) in that case, cancel any other pending runtime PM requests + regarding it and wait for all runtime PM operations on it in progress to + complete; returns 1 if there was a resume request pending and it was + necessary to execute the subsystem-level resume callback for the device to + satisfy that request, otherwise 0 is returned + void pm_suspend_ignore_children(struct device *dev, bool enable); - set/unset the power.ignore_children flag of the device int pm_runtime_set_active(struct device *dev); - - clear the device's 'power.runtime_error' flag, set the device's run-time + - clear the device's 'power.runtime_error' flag, set the device's runtime PM status to 'active' and update its parent's counter of 'active' children as appropriate (it is only valid to use this function if 'power.runtime_error' is set or 'power.disable_depth' is greater than @@ -390,7 +402,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: which is not active and the 'power.ignore_children' flag of which is unset void pm_runtime_set_suspended(struct device *dev); - - clear the device's 'power.runtime_error' flag, set the device's run-time + - clear the device's 'power.runtime_error' flag, set the device's runtime PM status to 'suspended' and update its parent's counter of 'active' children as appropriate (it is only valid to use this function if 'power.runtime_error' is set or 'power.disable_depth' is greater than @@ -400,6 +412,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: - return true if the device's runtime PM status is 'suspended' and its 'power.disable_depth' field is equal to zero, or false otherwise + bool pm_runtime_status_suspended(struct device *dev); + - return true if the device's runtime PM status is 'suspended' + void pm_runtime_allow(struct device *dev); - set the power.runtime_auto flag for the device and decrease its usage counter (used by the /sys/devices/.../power/control interface to @@ -411,7 +426,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: effectively prevent the device from being power managed at run time) void pm_runtime_no_callbacks(struct device *dev); - - set the power.no_callbacks flag for the device and remove the run-time + - set the power.no_callbacks flag for the device and remove the runtime PM attributes from /sys/devices/.../power (or prevent them from being added when the device is registered) @@ -431,7 +446,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: void pm_runtime_set_autosuspend_delay(struct device *dev, int delay); - set the power.autosuspend_delay value to 'delay' (expressed in - milliseconds); if 'delay' is negative then run-time suspends are + milliseconds); if 'delay' is negative then runtime suspends are prevented unsigned long pm_runtime_autosuspend_expiration(struct device *dev); @@ -470,35 +485,35 @@ pm_runtime_resume() pm_runtime_get_sync() pm_runtime_put_sync_suspend() -5. Run-time PM Initialization, Device Probing and Removal +5. Runtime PM Initialization, Device Probing and Removal -Initially, the run-time PM is disabled for all devices, which means that the -majority of the run-time PM helper funtions described in Section 4 will return +Initially, the runtime PM is disabled for all devices, which means that the +majority of the runtime PM helper funtions described in Section 4 will return -EAGAIN until pm_runtime_enable() is called for the device. -In addition to that, the initial run-time PM status of all devices is +In addition to that, the initial runtime PM status of all devices is 'suspended', but it need not reflect the actual physical state of the device. Thus, if the device is initially active (i.e. it is able to process I/O), its -run-time PM status must be changed to 'active', with the help of +runtime PM status must be changed to 'active', with the help of pm_runtime_set_active(), before pm_runtime_enable() is called for the device. -However, if the device has a parent and the parent's run-time PM is enabled, +However, if the device has a parent and the parent's runtime PM is enabled, calling pm_runtime_set_active() for the device will affect the parent, unless the parent's 'power.ignore_children' flag is set. Namely, in that case the parent won't be able to suspend at run time, using the PM core's helper functions, as long as the child's status is 'active', even if the child's -run-time PM is still disabled (i.e. pm_runtime_enable() hasn't been called for +runtime PM is still disabled (i.e. pm_runtime_enable() hasn't been called for the child yet or pm_runtime_disable() has been called for it). For this reason, once pm_runtime_set_active() has been called for the device, pm_runtime_enable() -should be called for it too as soon as reasonably possible or its run-time PM +should be called for it too as soon as reasonably possible or its runtime PM status should be changed back to 'suspended' with the help of pm_runtime_set_suspended(). -If the default initial run-time PM status of the device (i.e. 'suspended') +If the default initial runtime PM status of the device (i.e. 'suspended') reflects the actual state of the device, its bus type's or its driver's ->probe() callback will likely need to wake it up using one of the PM core's helper functions described in Section 4. In that case, pm_runtime_resume() -should be used. Of course, for this purpose the device's run-time PM has to be +should be used. Of course, for this purpose the device's runtime PM has to be enabled earlier by calling pm_runtime_enable(). If the device bus type's or driver's ->probe() callback runs @@ -529,33 +544,33 @@ The user space can effectively disallow the driver of the device to power manage it at run time by changing the value of its /sys/devices/.../power/control attribute to "on", which causes pm_runtime_forbid() to be called. In principle, this mechanism may also be used by the driver to effectively turn off the -run-time power management of the device until the user space turns it on. -Namely, during the initialization the driver can make sure that the run-time PM +runtime power management of the device until the user space turns it on. +Namely, during the initialization the driver can make sure that the runtime PM status of the device is 'active' and call pm_runtime_forbid(). It should be noted, however, that if the user space has already intentionally changed the value of /sys/devices/.../power/control to "auto" to allow the driver to power manage the device at run time, the driver may confuse it by using pm_runtime_forbid() this way. -6. Run-time PM and System Sleep +6. Runtime PM and System Sleep -Run-time PM and system sleep (i.e., system suspend and hibernation, also known +Runtime PM and system sleep (i.e., system suspend and hibernation, also known as suspend-to-RAM and suspend-to-disk) interact with each other in a couple of ways. If a device is active when a system sleep starts, everything is straightforward. But what should happen if the device is already suspended? -The device may have different wake-up settings for run-time PM and system sleep. -For example, remote wake-up may be enabled for run-time suspend but disallowed +The device may have different wake-up settings for runtime PM and system sleep. +For example, remote wake-up may be enabled for runtime suspend but disallowed for system sleep (device_may_wakeup(dev) returns 'false'). When this happens, the subsystem-level system suspend callback is responsible for changing the device's wake-up setting (it may leave that to the device driver's system suspend routine). It may be necessary to resume the device and suspend it again in order to do so. The same is true if the driver uses different power levels -or other settings for run-time suspend and system sleep. +or other settings for runtime suspend and system sleep. -During system resume, devices generally should be brought back to full power, -even if they were suspended before the system sleep began. There are several -reasons for this, including: +During system resume, the simplest approach is to bring all devices back to full +power, even if they had been suspended before the system suspend began. There +are several reasons for this, including: * The device might need to switch power levels, wake-up settings, etc. @@ -570,18 +585,50 @@ reasons for this, including: * The device might need to be reset. * Even though the device was suspended, if its usage counter was > 0 then most - likely it would need a run-time resume in the near future anyway. - - * Always going back to full power is simplest. + likely it would need a runtime resume in the near future anyway. -If the device was suspended before the sleep began, then its run-time PM status -will have to be updated to reflect the actual post-system sleep status. The way -to do this is: +If the device had been suspended before the system suspend began and it's +brought back to full power during resume, then its runtime PM status will have +to be updated to reflect the actual post-system sleep status. The way to do +this is: pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); +The PM core always increments the runtime usage counter before calling the +->suspend() callback and decrements it after calling the ->resume() callback. +Hence disabling runtime PM temporarily like this will not cause any runtime +suspend attempts to be permanently lost. If the usage count goes to zero +following the return of the ->resume() callback, the ->runtime_idle() callback +will be invoked as usual. + +On some systems, however, system sleep is not entered through a global firmware +or hardware operation. Instead, all hardware components are put into low-power +states directly by the kernel in a coordinated way. Then, the system sleep +state effectively follows from the states the hardware components end up in +and the system is woken up from that state by a hardware interrupt or a similar +mechanism entirely under the kernel's control. As a result, the kernel never +gives control away and the states of all devices during resume are precisely +known to it. If that is the case and none of the situations listed above takes +place (in particular, if the system is not waking up from hibernation), it may +be more efficient to leave the devices that had been suspended before the system +suspend began in the suspended state. + +The PM core does its best to reduce the probability of race conditions between +the runtime PM and system suspend/resume (and hibernation) callbacks by carrying +out the following operations: + + * During system suspend it calls pm_runtime_get_noresume() and + pm_runtime_barrier() for every device right before executing the + subsystem-level .suspend() callback for it. In addition to that it calls + pm_runtime_disable() for every device right after executing the + subsystem-level .suspend() callback for it. + + * During system resume it calls pm_runtime_enable() and pm_runtime_put_sync() + for every device right before and right after executing the subsystem-level + .resume() callback for it, respectively. + 7. Generic subsystem callbacks Subsystems may wish to conserve code space by using the set of generic power @@ -606,40 +653,68 @@ driver/base/power/generic_ops.c: callback provided by its driver and return its result, or return 0 if not defined + int pm_generic_suspend_noirq(struct device *dev); + - if pm_runtime_suspended(dev) returns "false", invoke the ->suspend_noirq() + callback provided by the device's driver and return its result, or return + 0 if not defined + int pm_generic_resume(struct device *dev); - invoke the ->resume() callback provided by the driver of this device and, if successful, change the device's runtime PM status to 'active' + int pm_generic_resume_noirq(struct device *dev); + - invoke the ->resume_noirq() callback provided by the driver of this device + int pm_generic_freeze(struct device *dev); - if the device has not been suspended at run time, invoke the ->freeze() callback provided by its driver and return its result, or return 0 if not defined + int pm_generic_freeze_noirq(struct device *dev); + - if pm_runtime_suspended(dev) returns "false", invoke the ->freeze_noirq() + callback provided by the device's driver and return its result, or return + 0 if not defined + int pm_generic_thaw(struct device *dev); - if the device has not been suspended at run time, invoke the ->thaw() callback provided by its driver and return its result, or return 0 if not defined + int pm_generic_thaw_noirq(struct device *dev); + - if pm_runtime_suspended(dev) returns "false", invoke the ->thaw_noirq() + callback provided by the device's driver and return its result, or return + 0 if not defined + int pm_generic_poweroff(struct device *dev); - if the device has not been suspended at run time, invoke the ->poweroff() callback provided by its driver and return its result, or return 0 if not defined + int pm_generic_poweroff_noirq(struct device *dev); + - if pm_runtime_suspended(dev) returns "false", run the ->poweroff_noirq() + callback provided by the device's driver and return its result, or return + 0 if not defined + int pm_generic_restore(struct device *dev); - invoke the ->restore() callback provided by the driver of this device and, if successful, change the device's runtime PM status to 'active' + int pm_generic_restore_noirq(struct device *dev); + - invoke the ->restore_noirq() callback provided by the device's driver + These functions can be assigned to the ->runtime_idle(), ->runtime_suspend(), -->runtime_resume(), ->suspend(), ->resume(), ->freeze(), ->thaw(), ->poweroff(), -or ->restore() callback pointers in the subsystem-level dev_pm_ops structures. +->runtime_resume(), ->suspend(), ->suspend_noirq(), ->resume(), +->resume_noirq(), ->freeze(), ->freeze_noirq(), ->thaw(), ->thaw_noirq(), +->poweroff(), ->poweroff_noirq(), ->restore(), ->restore_noirq() callback +pointers in the subsystem-level dev_pm_ops structures. If a subsystem wishes to use all of them at the same time, it can simply assign the GENERIC_SUBSYS_PM_OPS macro, defined in include/linux/pm.h, to its dev_pm_ops structure pointer. Device drivers that wish to use the same function as a system suspend, freeze, -poweroff and run-time suspend callback, and similarly for system resume, thaw, -restore, and run-time resume, can achieve this with the help of the +poweroff and runtime suspend callback, and similarly for system resume, thaw, +restore, and runtime resume, can achieve this with the help of the UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its last argument to NULL). @@ -649,7 +724,7 @@ Some "devices" are only logical sub-devices of their parent and cannot be power-managed on their own. (The prototype example is a USB interface. Entire USB devices can go into low-power mode or send wake-up requests, but neither is possible for individual interfaces.) The drivers for these devices have no -need of run-time PM callbacks; if the callbacks did exist, ->runtime_suspend() +need of runtime PM callbacks; if the callbacks did exist, ->runtime_suspend() and ->runtime_resume() would always return 0 without doing anything else and ->runtime_idle() would always call pm_runtime_suspend(). @@ -657,7 +732,7 @@ Subsystems can tell the PM core about these devices by calling pm_runtime_no_callbacks(). This should be done after the device structure is initialized and before it is registered (although after device registration is also okay). The routine will set the device's power.no_callbacks flag and -prevent the non-debugging run-time PM sysfs attributes from being created. +prevent the non-debugging runtime PM sysfs attributes from being created. When power.no_callbacks is set, the PM core will not invoke the ->runtime_idle(), ->runtime_suspend(), or ->runtime_resume() callbacks. @@ -665,7 +740,7 @@ Instead it will assume that suspends and resumes always succeed and that idle devices should be suspended. As a consequence, the PM core will never directly inform the device's subsystem -or driver about run-time power changes. Instead, the driver for the device's +or driver about runtime power changes. Instead, the driver for the device's parent must take responsibility for telling the device's driver when the parent's power state changes. @@ -676,13 +751,13 @@ A device should be put in a low-power state only when there's some reason to think it will remain in that state for a substantial time. A common heuristic says that a device which hasn't been used for a while is liable to remain unused; following this advice, drivers should not allow devices to be suspended -at run-time until they have been inactive for some minimum period. Even when +at runtime until they have been inactive for some minimum period. Even when the heuristic ends up being non-optimal, it will still prevent devices from "bouncing" too rapidly between low-power and full-power states. The term "autosuspend" is an historical remnant. It doesn't mean that the device is automatically suspended (the subsystem or driver still has to call -the appropriate PM routines); rather it means that run-time suspends will +the appropriate PM routines); rather it means that runtime suspends will automatically be delayed until the desired period of inactivity has elapsed. Inactivity is determined based on the power.last_busy field. Drivers should diff --git a/Documentation/rbtree.txt b/Documentation/rbtree.txt index 19f8278c385..8d32d85a523 100644 --- a/Documentation/rbtree.txt +++ b/Documentation/rbtree.txt @@ -196,15 +196,20 @@ Support for Augmented rbtrees Augmented rbtree is an rbtree with "some" additional data stored in each node. This data can be used to augment some new functionality to rbtree. Augmented rbtree is an optional feature built on top of basic rbtree -infrastructure. rbtree user who wants this feature will have an augment -callback function in rb_root initialized. - -This callback function will be called from rbtree core routines whenever -a node has a change in one or both of its children. It is the responsibility -of the callback function to recalculate the additional data that is in the -rb node using new children information. Note that if this new additional -data affects the parent node's additional data, then callback function has -to handle it and do the recursive updates. +infrastructure. An rbtree user who wants this feature will have to call the +augmentation functions with the user provided augmentation callback +when inserting and erasing nodes. + +On insertion, the user must call rb_augment_insert() once the new node is in +place. This will cause the augmentation function callback to be called for +each node between the new node and the root which has been affected by the +insertion. + +When erasing a node, the user must call rb_augment_erase_begin() first to +retrieve the deepest node on the rebalance path. Then, after erasing the +original node, the user must call rb_augment_erase_end() with the deepest +node found earlier. This will cause the augmentation function to be called +for each affected node between the deepest node and the root. Interval tree is an example of augmented rb tree. Reference - diff --git a/Documentation/s390/TAPE b/Documentation/s390/TAPE deleted file mode 100644 index c639aa5603f..00000000000 --- a/Documentation/s390/TAPE +++ /dev/null @@ -1,122 +0,0 @@ -Channel attached Tape device driver - ------------------------------WARNING----------------------------------------- -This driver is considered to be EXPERIMENTAL. Do NOT use it in -production environments. Feel free to test it and report problems back to us. ------------------------------------------------------------------------------ - -The LINUX for zSeries tape device driver manages channel attached tape drives -which are compatible to IBM 3480 or IBM 3490 magnetic tape subsystems. This -includes various models of these devices (for example the 3490E). - - -Tape driver features - -The device driver supports a maximum of 128 tape devices. -No official LINUX device major number is assigned to the zSeries tape device -driver. It allocates major numbers dynamically and reports them on system -startup. -Typically it will get major number 254 for both the character device front-end -and the block device front-end. - -The tape device driver needs no kernel parameters. All supported devices -present are detected on driver initialization at system startup or module load. -The devices detected are ordered by their subchannel numbers. The device with -the lowest subchannel number becomes device 0, the next one will be device 1 -and so on. - - -Tape character device front-end - -The usual way to read or write to the tape device is through the character -device front-end. The zSeries tape device driver provides two character devices -for each physical device -- the first of these will rewind automatically when -it is closed, the second will not rewind automatically. - -The character device nodes are named /dev/rtibm0 (rewinding) and /dev/ntibm0 -(non-rewinding) for the first device, /dev/rtibm1 and /dev/ntibm1 for the -second, and so on. - -The character device front-end can be used as any other LINUX tape device. You -can write to it and read from it using LINUX facilities such as GNU tar. The -tool mt can be used to perform control operations, such as rewinding the tape -or skipping a file. - -Most LINUX tape software should work with either tape character device. - - -Tape block device front-end - -The tape device may also be accessed as a block device in read-only mode. -This could be used for software installation in the same way as it is used with -other operation systems on the zSeries platform (and most LINUX -distributions are shipped on compact disk using ISO9660 filesystems). - -One block device node is provided for each physical device. These are named -/dev/btibm0 for the first device, /dev/btibm1 for the second and so on. -You should only use the ISO9660 filesystem on LINUX for zSeries tapes because -the physical tape devices cannot perform fast seeks and the ISO9660 system is -optimized for this situation. - - -Tape block device example - -In this example a tape with an ISO9660 filesystem is created using the first -tape device. ISO9660 filesystem support must be built into your system kernel -for this. -The mt command is used to issue tape commands and the mkisofs command to -create an ISO9660 filesystem: - -- create a LINUX directory (somedir) with the contents of the filesystem - mkdir somedir - cp contents somedir - -- insert a tape - -- ensure the tape is at the beginning - mt -f /dev/ntibm0 rewind - -- set the blocksize of the character driver. The blocksize 2048 bytes - is commonly used on ISO9660 CD-Roms - mt -f /dev/ntibm0 setblk 2048 - -- write the filesystem to the character device driver - mkisofs -o /dev/ntibm0 somedir - -- rewind the tape again - mt -f /dev/ntibm0 rewind - -- Now you can mount your new filesystem as a block device: - mount -t iso9660 -o ro,block=2048 /dev/btibm0 /mnt - -TODO List - - - Driver has to be stabilized still - -BUGS - -This driver is considered BETA, which means some weaknesses may still -be in it. -If an error occurs which cannot be handled by the code you will get a -sense-data dump.In that case please do the following: - -1. set the tape driver debug level to maximum: - echo 6 >/proc/s390dbf/tape/level - -2. re-perform the actions which produced the bug. (Hopefully the bug will - reappear.) - -3. get a snapshot from the debug-feature: - cat /proc/s390dbf/tape/hex_ascii >somefile - -4. Now put the snapshot together with a detailed description of the situation - that led to the bug: - - Which tool did you use? - - Which hardware do you have? - - Was your tape unit online? - - Is it a shared tape unit? - -5. Send an email with your bug report to: - mailto:Linux390@de.ibm.com - - diff --git a/Documentation/sound/alsa/HD-Audio-Controls.txt b/Documentation/sound/alsa/HD-Audio-Controls.txt new file mode 100644 index 00000000000..1482035243e --- /dev/null +++ b/Documentation/sound/alsa/HD-Audio-Controls.txt @@ -0,0 +1,100 @@ +This file explains the codec-specific mixer controls. + +Realtek codecs +-------------- + +* Channel Mode + This is an enum control to change the surround-channel setup, + appears only when the surround channels are available. + It gives the number of channels to be used, "2ch", "4ch", "6ch", + and "8ch". According to the configuration, this also controls the + jack-retasking of multi-I/O jacks. + +* Auto-Mute Mode + This is an enum control to change the auto-mute behavior of the + headphone and line-out jacks. If built-in speakers and headphone + and/or line-out jacks are available on a machine, this controls + appears. + When there are only either headphones or line-out jacks, it gives + "Disabled" and "Enabled" state. When enabled, the speaker is muted + automatically when a jack is plugged. + + When both headphone and line-out jacks are present, it gives + "Disabled", "Speaker Only" and "Line-Out+Speaker". When + speaker-only is chosen, plugging into a headphone or a line-out jack + mutes the speakers, but not line-outs. When line-out+speaker is + selected, plugging to a headphone jack mutes both speakers and + line-outs. + + +IDT/Sigmatel codecs +------------------- + +* Analog Loopback + This control enables/disables the analog-loopback circuit. This + appears only when "loopback" is set to true in a codec hint + (see HD-Audio.txt). Note that on some codecs the analog-loopback + and the normal PCM playback are exclusive, i.e. when this is on, you + won't hear any PCM stream. + +* Swap Center/LFE + Swaps the center and LFE channel order. Normally, the left + corresponds to the center and the right to the LFE. When this is + ON, the left to the LFE and the right to the center. + +* Headphone as Line Out + When this control is ON, treat the headphone jacks as line-out + jacks. That is, the headphone won't auto-mute the other line-outs, + and no HP-amp is set to the pins. + +* Mic Jack Mode, Line Jack Mode, etc + These enum controls the direction and the bias of the input jack + pins. Depending on the jack type, it can set as "Mic In" and "Line + In", for determining the input bias, or it can be set to "Line Out" + when the pin is a multi-I/O jack for surround channels. + + +VIA codecs +---------- + +* Smart 5.1 + An enum control to re-task the multi-I/O jacks for surround outputs. + When it's ON, the corresponding input jacks (usually a line-in and a + mic-in) are switched as the surround and the CLFE output jacks. + +* Independent HP + When this enum control is enabled, the headphone output is routed + from an individual stream (the third PCM such as hw:0,2) instead of + the primary stream. In the case the headphone DAC is shared with a + side or a CLFE-channel DAC, the DAC is switched to the headphone + automatically. + +* Loopback Mixing + An enum control to determine whether the analog-loopback route is + enabled or not. When it's enabled, the analog-loopback is mixed to + the front-channel. Also, the same route is used for the headphone + and speaker outputs. As a side-effect, when this mode is set, the + individual volume controls will be no longer available for + headphones and speakers because there is only one DAC connected to a + mixer widget. + +* Dynamic Power-Control + This control determines whether the dynamic power-control per jack + detection is enabled or not. When enabled, the widgets power state + (D0/D3) are changed dynamically depending on the jack plugging + state for saving power consumptions. However, if your system + doesn't provide a proper jack-detection, this won't work; in such a + case, turn this control OFF. + +* Jack Detect + This control is provided only for VT1708 codec which gives no proper + unsolicited event per jack plug. When this is on, the driver polls + the jack detection so that the headphone auto-mute can work, while + turning this off would reduce the power consumption. + + +Conexant codecs +--------------- + +* Auto-Mute Mode + See Reatek codecs. diff --git a/Documentation/spi/ep93xx_spi b/Documentation/spi/ep93xx_spi index 6325f5b4863..d8eb01c15db 100644 --- a/Documentation/spi/ep93xx_spi +++ b/Documentation/spi/ep93xx_spi @@ -88,6 +88,16 @@ static void __init ts72xx_init_machine(void) ARRAY_SIZE(ts72xx_spi_devices)); } +The driver can use DMA for the transfers also. In this case ts72xx_spi_info +becomes: + +static struct ep93xx_spi_info ts72xx_spi_info = { + .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices), + .use_dma = true; +}; + +Note that CONFIG_EP93XX_DMA should be enabled as well. + Thanks to ========= Martin Guy, H. Hartley Sweeten and others who helped me during development of diff --git a/Documentation/spi/pxa2xx b/Documentation/spi/pxa2xx index 493dada5737..00511e08db7 100644 --- a/Documentation/spi/pxa2xx +++ b/Documentation/spi/pxa2xx @@ -22,15 +22,11 @@ Typically a SPI master is defined in the arch/.../mach-*/board-*.c as a found in include/linux/spi/pxa2xx_spi.h: struct pxa2xx_spi_master { - enum pxa_ssp_type ssp_type; u32 clock_enable; u16 num_chipselect; u8 enable_dma; }; -The "pxa2xx_spi_master.ssp_type" field must have a value between 1 and 3 and -informs the driver which features a particular SSP supports. - The "pxa2xx_spi_master.clock_enable" field is used to enable/disable the corresponding SSP peripheral block in the "Clock Enable Register (CKEN"). See the "PXA2xx Developer Manual" section "Clocks and Power Management". @@ -61,7 +57,6 @@ static struct resource pxa_spi_nssp_resources[] = { }; static struct pxa2xx_spi_master pxa_nssp_master_info = { - .ssp_type = PXA25x_NSSP, /* Type of SSP */ .clock_enable = CKEN_NSSP, /* NSSP Peripheral clock */ .num_chipselect = 1, /* Matches the number of chips attached to NSSP */ .enable_dma = 1, /* Enables NSSP DMA */ diff --git a/Documentation/spinlocks.txt b/Documentation/spinlocks.txt index 2e3c64b1a6a..9dbe885ecd8 100644 --- a/Documentation/spinlocks.txt +++ b/Documentation/spinlocks.txt @@ -13,18 +13,8 @@ static DEFINE_SPINLOCK(xxx_lock); The above is always safe. It will disable interrupts _locally_, but the spinlock itself will guarantee the global lock, so it will guarantee that there is only one thread-of-control within the region(s) protected by that -lock. This works well even under UP. The above sequence under UP -essentially is just the same as doing - - unsigned long flags; - - save_flags(flags); cli(); - ... critical section ... - restore_flags(flags); - -so the code does _not_ need to worry about UP vs SMP issues: the spinlocks -work correctly under both (and spinlocks are actually more efficient on -architectures that allow doing the "save_flags + cli" in one operation). +lock. This works well even under UP also, so the code does _not_ need to +worry about UP vs SMP issues: the spinlocks work correctly under both. NOTE! Implications of spin_locks for memory are further described in: @@ -36,27 +26,7 @@ The above is usually pretty simple (you usually need and want only one spinlock for most things - using more than one spinlock can make things a lot more complex and even slower and is usually worth it only for sequences that you _know_ need to be split up: avoid it at all cost if you -aren't sure). HOWEVER, it _does_ mean that if you have some code that does - - cli(); - .. critical section .. - sti(); - -and another sequence that does - - spin_lock_irqsave(flags); - .. critical section .. - spin_unlock_irqrestore(flags); - -then they are NOT mutually exclusive, and the critical regions can happen -at the same time on two different CPU's. That's fine per se, but the -critical regions had better be critical for different things (ie they -can't stomp on each other). - -The above is a problem mainly if you end up mixing code - for example the -routines in ll_rw_block() tend to use cli/sti to protect the atomicity of -their actions, and if a driver uses spinlocks instead then you should -think about issues like the above. +aren't sure). This is really the only really hard part about spinlocks: once you start using spinlocks they tend to expand to areas you might not have noticed @@ -120,11 +90,10 @@ Lesson 3: spinlocks revisited. The single spin-lock primitives above are by no means the only ones. They are the most safe ones, and the ones that work under all circumstances, -but partly _because_ they are safe they are also fairly slow. They are -much faster than a generic global cli/sti pair, but slower than they'd -need to be, because they do have to disable interrupts (which is just a -single instruction on a x86, but it's an expensive one - and on other -architectures it can be worse). +but partly _because_ they are safe they are also fairly slow. They are slower +than they'd need to be, because they do have to disable interrupts +(which is just a single instruction on a x86, but it's an expensive one - +and on other architectures it can be worse). If you have a case where you have to protect a data structure across several CPU's and you want to use spinlocks you can potentially use diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 5e7cb39ad19..1c7fb0a94e2 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -17,23 +17,21 @@ before actually making adjustments. Currently, these files might (depending on your configuration) show up in /proc/sys/kernel: -- acpi_video_flags + - acct +- acpi_video_flags +- auto_msgmni - bootloader_type [ X86 only ] - bootloader_version [ X86 only ] - callhome [ S390 only ] -- auto_msgmni - core_pattern - core_pipe_limit - core_uses_pid - ctrl-alt-del -- dentry-state - dmesg_restrict - domainname - hostname - hotplug -- java-appletviewer [ binfmt_java, obsolete ] -- java-interpreter [ binfmt_java, obsolete ] - kptr_restrict - kstack_depth_to_print [ X86 only ] - l2cr [ PPC only ] @@ -48,10 +46,14 @@ show up in /proc/sys/kernel: - overflowgid - overflowuid - panic +- panic_on_oops +- panic_on_unrecovered_nmi - pid_max - powersave-nap [ PPC only ] -- panic_on_unrecovered_nmi - printk +- printk_delay +- printk_ratelimit +- printk_ratelimit_burst - randomize_va_space - real-root-dev ==> Documentation/initrd.txt - reboot-cmd [ SPARC only ] @@ -62,6 +64,7 @@ show up in /proc/sys/kernel: - shmall - shmmax [ sysv ipc ] - shmmni +- softlockup_thresh - stop-a [ SPARC only ] - sysrq ==> Documentation/sysrq.txt - tainted @@ -71,15 +74,6 @@ show up in /proc/sys/kernel: ============================================================== -acpi_video_flags: - -flags - -See Doc*/kernel/power/video.txt, it allows mode of video boot to be -set during run time. - -============================================================== - acct: highwater lowwater frequency @@ -97,6 +91,25 @@ valid for 30 seconds. ============================================================== +acpi_video_flags: + +flags + +See Doc*/kernel/power/video.txt, it allows mode of video boot to be +set during run time. + +============================================================== + +auto_msgmni: + +Enables/Disables automatic recomputing of msgmni upon memory add/remove +or upon ipc namespace creation/removal (see the msgmni description +above). Echoing "1" into this file enables msgmni automatic recomputing. +Echoing "0" turns it off. auto_msgmni default value is 1. + + +============================================================== + bootloader_type: x86 bootloader identification @@ -172,22 +185,24 @@ core_pattern is used to specify a core dumpfile pattern name. core_pipe_limit: -This sysctl is only applicable when core_pattern is configured to pipe core -files to a user space helper (when the first character of core_pattern is a '|', -see above). When collecting cores via a pipe to an application, it is -occasionally useful for the collecting application to gather data about the -crashing process from its /proc/pid directory. In order to do this safely, the -kernel must wait for the collecting process to exit, so as not to remove the -crashing processes proc files prematurely. This in turn creates the possibility -that a misbehaving userspace collecting process can block the reaping of a -crashed process simply by never exiting. This sysctl defends against that. It -defines how many concurrent crashing processes may be piped to user space -applications in parallel. If this value is exceeded, then those crashing -processes above that value are noted via the kernel log and their cores are -skipped. 0 is a special value, indicating that unlimited processes may be -captured in parallel, but that no waiting will take place (i.e. the collecting -process is not guaranteed access to /proc/<crashing pid>/). This value defaults -to 0. +This sysctl is only applicable when core_pattern is configured to pipe +core files to a user space helper (when the first character of +core_pattern is a '|', see above). When collecting cores via a pipe +to an application, it is occasionally useful for the collecting +application to gather data about the crashing process from its +/proc/pid directory. In order to do this safely, the kernel must wait +for the collecting process to exit, so as not to remove the crashing +processes proc files prematurely. This in turn creates the +possibility that a misbehaving userspace collecting process can block +the reaping of a crashed process simply by never exiting. This sysctl +defends against that. It defines how many concurrent crashing +processes may be piped to user space applications in parallel. If +this value is exceeded, then those crashing processes above that value +are noted via the kernel log and their cores are skipped. 0 is a +special value, indicating that unlimited processes may be captured in +parallel, but that no waiting will take place (i.e. the collecting +process is not guaranteed access to /proc/<crashing pid>/). This +value defaults to 0. ============================================================== @@ -218,14 +233,14 @@ to decide what to do with it. dmesg_restrict: -This toggle indicates whether unprivileged users are prevented from using -dmesg(8) to view messages from the kernel's log buffer. When -dmesg_restrict is set to (0) there are no restrictions. When +This toggle indicates whether unprivileged users are prevented +from using dmesg(8) to view messages from the kernel's log buffer. +When dmesg_restrict is set to (0) there are no restrictions. When dmesg_restrict is set set to (1), users must have CAP_SYSLOG to use dmesg(8). -The kernel config option CONFIG_SECURITY_DMESG_RESTRICT sets the default -value of dmesg_restrict. +The kernel config option CONFIG_SECURITY_DMESG_RESTRICT sets the +default value of dmesg_restrict. ============================================================== @@ -256,13 +271,6 @@ Default value is "/sbin/hotplug". ============================================================== -l2cr: (PPC only) - -This flag controls the L2 cache of G3 processor boards. If -0, the cache is disabled. Enabled if nonzero. - -============================================================== - kptr_restrict: This toggle indicates whether restrictions are placed on @@ -283,6 +291,13 @@ kernel stack. ============================================================== +l2cr: (PPC only) + +This flag controls the L2 cache of G3 processor boards. If +0, the cache is disabled. Enabled if nonzero. + +============================================================== + modules_disabled: A toggle value indicating if modules are allowed to be loaded @@ -293,6 +308,21 @@ to false. ============================================================== +nmi_watchdog: + +Enables/Disables the NMI watchdog on x86 systems. When the value is +non-zero the NMI watchdog is enabled and will continuously test all +online cpus to determine whether or not they are still functioning +properly. Currently, passing "nmi_watchdog=" parameter at boot time is +required for this function to work. + +If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel +parameter), the NMI watchdog shares registers with oprofile. By +disabling the NMI watchdog, oprofile may have more registers to +utilize. + +============================================================== + osrelease, ostype & version: # cat osrelease @@ -312,10 +342,10 @@ The only way to tune these values is to rebuild the kernel :-) overflowgid & overflowuid: -if your architecture did not always support 32-bit UIDs (i.e. arm, i386, -m68k, sh, and sparc32), a fixed UID and GID will be returned to -applications that use the old 16-bit UID/GID system calls, if the actual -UID or GID would exceed 65535. +if your architecture did not always support 32-bit UIDs (i.e. arm, +i386, m68k, sh, and sparc32), a fixed UID and GID will be returned to +applications that use the old 16-bit UID/GID system calls, if the +actual UID or GID would exceed 65535. These sysctls allow you to change the value of the fixed UID and GID. The default is 65534. @@ -324,9 +354,22 @@ The default is 65534. panic: -The value in this file represents the number of seconds the -kernel waits before rebooting on a panic. When you use the -software watchdog, the recommended setting is 60. +The value in this file represents the number of seconds the kernel +waits before rebooting on a panic. When you use the software watchdog, +the recommended setting is 60. + +============================================================== + +panic_on_unrecovered_nmi: + +The default Linux behaviour on an NMI of either memory or unknown is +to continue operation. For many environments such as scientific +computing it is preferable that the box is taken out and the error +dealt with than an uncorrected parity/ECC error get propagated. + +A small number of systems do generate NMI's for bizarre random reasons +such as power management so the default is off. That sysctl works like +the existing panic controls already in that directory. ============================================================== @@ -376,6 +419,14 @@ the different loglevels. ============================================================== +printk_delay: + +Delay each printk message in printk_delay milliseconds + +Value from 0 - 10000 is allowed. + +============================================================== + printk_ratelimit: Some warning messages are rate limited. printk_ratelimit specifies @@ -395,15 +446,7 @@ send before ratelimiting kicks in. ============================================================== -printk_delay: - -Delay each printk message in printk_delay milliseconds - -Value from 0 - 10000 is allowed. - -============================================================== - -randomize-va-space: +randomize_va_space: This option can be used to select the type of process address space randomization that is used in the system, for architectures @@ -466,11 +509,11 @@ are doing anyway :) ============================================================== -shmmax: +shmmax: This value can be used to query and set the run time limit on the maximum shared memory segment size that can be created. -Shared memory segments up to 1Gb are now supported in the +Shared memory segments up to 1Gb are now supported in the kernel. This value defaults to SHMMAX. ============================================================== @@ -484,7 +527,7 @@ tunable to zero will disable the softlockup detection altogether. ============================================================== -tainted: +tainted: Non-zero if the kernel has been tainted. Numeric values, which can be ORed together: @@ -509,49 +552,11 @@ can be ORed together: ============================================================== -auto_msgmni: - -Enables/Disables automatic recomputing of msgmni upon memory add/remove or -upon ipc namespace creation/removal (see the msgmni description above). -Echoing "1" into this file enables msgmni automatic recomputing. -Echoing "0" turns it off. -auto_msgmni default value is 1. - -============================================================== - -nmi_watchdog: - -Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero -the NMI watchdog is enabled and will continuously test all online cpus to -determine whether or not they are still functioning properly. Currently, -passing "nmi_watchdog=" parameter at boot time is required for this function -to work. - -If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the -NMI watchdog shares registers with oprofile. By disabling the NMI watchdog, -oprofile may have more registers to utilize. - -============================================================== - unknown_nmi_panic: -The value in this file affects behavior of handling NMI. When the value is -non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel -debugging information is displayed on console. - -NMI switch that most IA32 servers have fires unknown NMI up, for example. -If a system hangs up, try pressing the NMI switch. - -============================================================== - -panic_on_unrecovered_nmi: - -The default Linux behaviour on an NMI of either memory or unknown is to continue -operation. For many environments such as scientific computing it is preferable -that the box is taken out and the error dealt with than an uncorrected -parity/ECC error get propogated. - -A small number of systems do generate NMI's for bizarre random reasons such as -power management so the default is off. That sysctl works like the existing -panic controls already in that directory. +The value in this file affects behavior of handling NMI. When the +value is non-zero, unknown NMI is trapped and then panic occurs. At +that time, kernel debugging information is displayed on console. +NMI switch that most IA32 servers have fires unknown NMI up, for +example. If a system hangs up, try pressing the NMI switch. diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index c83bd6b4e6e..d0d0bb9e3e2 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -22,14 +22,15 @@ current_tracer. Instead of that, add probe points via Synopsis of kprobe_events ------------------------- - p[:[GRP/]EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS] : Set a probe - r[:[GRP/]EVENT] SYMBOL[+0] [FETCHARGS] : Set a return probe + p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe + r[:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe -:[GRP/]EVENT : Clear a probe GRP : Group name. If omitted, use "kprobes" for it. EVENT : Event name. If omitted, the event name is generated - based on SYMBOL+offs or MEMADDR. - SYMBOL[+offs] : Symbol+offset where the probe is inserted. + based on SYM+offs or MEMADDR. + MOD : Module name which has given SYM. + SYM[+offs] : Symbol+offset where the probe is inserted. MEMADDR : Address where the probe is inserted. FETCHARGS : Arguments. Each probe can have up to 128 args. diff --git a/Documentation/vDSO/parse_vdso.c b/Documentation/vDSO/parse_vdso.c new file mode 100644 index 00000000000..85870208edc --- /dev/null +++ b/Documentation/vDSO/parse_vdso.c @@ -0,0 +1,256 @@ +/* + * parse_vdso.c: Linux reference vDSO parser + * Written by Andrew Lutomirski, 2011. + * + * This code is meant to be linked in to various programs that run on Linux. + * As such, it is available with as few restrictions as possible. This file + * is licensed under the Creative Commons Zero License, version 1.0, + * available at http://creativecommons.org/publicdomain/zero/1.0/legalcode + * + * The vDSO is a regular ELF DSO that the kernel maps into user space when + * it starts a program. It works equally well in statically and dynamically + * linked binaries. + * + * This code is tested on x86_64. In principle it should work on any 64-bit + * architecture that has a vDSO. + */ + +#include <stdbool.h> +#include <stdint.h> +#include <string.h> +#include <elf.h> + +/* + * To use this vDSO parser, first call one of the vdso_init_* functions. + * If you've already parsed auxv, then pass the value of AT_SYSINFO_EHDR + * to vdso_init_from_sysinfo_ehdr. Otherwise pass auxv to vdso_init_from_auxv. + * Then call vdso_sym for each symbol you want. For example, to look up + * gettimeofday on x86_64, use: + * + * <some pointer> = vdso_sym("LINUX_2.6", "gettimeofday"); + * or + * <some pointer> = vdso_sym("LINUX_2.6", "__vdso_gettimeofday"); + * + * vdso_sym will return 0 if the symbol doesn't exist or if the init function + * failed or was not called. vdso_sym is a little slow, so its return value + * should be cached. + * + * vdso_sym is threadsafe; the init functions are not. + * + * These are the prototypes: + */ +extern void vdso_init_from_auxv(void *auxv); +extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); +extern void *vdso_sym(const char *version, const char *name); + + +/* And here's the code. */ + +#ifndef __x86_64__ +# error Not yet ported to non-x86_64 architectures +#endif + +static struct vdso_info +{ + bool valid; + + /* Load information */ + uintptr_t load_addr; + uintptr_t load_offset; /* load_addr - recorded vaddr */ + + /* Symbol table */ + Elf64_Sym *symtab; + const char *symstrings; + Elf64_Word *bucket, *chain; + Elf64_Word nbucket, nchain; + + /* Version table */ + Elf64_Versym *versym; + Elf64_Verdef *verdef; +} vdso_info; + +/* Straight from the ELF specification. */ +static unsigned long elf_hash(const unsigned char *name) +{ + unsigned long h = 0, g; + while (*name) + { + h = (h << 4) + *name++; + if (g = h & 0xf0000000) + h ^= g >> 24; + h &= ~g; + } + return h; +} + +void vdso_init_from_sysinfo_ehdr(uintptr_t base) +{ + size_t i; + bool found_vaddr = false; + + vdso_info.valid = false; + + vdso_info.load_addr = base; + + Elf64_Ehdr *hdr = (Elf64_Ehdr*)base; + Elf64_Phdr *pt = (Elf64_Phdr*)(vdso_info.load_addr + hdr->e_phoff); + Elf64_Dyn *dyn = 0; + + /* + * We need two things from the segment table: the load offset + * and the dynamic table. + */ + for (i = 0; i < hdr->e_phnum; i++) + { + if (pt[i].p_type == PT_LOAD && !found_vaddr) { + found_vaddr = true; + vdso_info.load_offset = base + + (uintptr_t)pt[i].p_offset + - (uintptr_t)pt[i].p_vaddr; + } else if (pt[i].p_type == PT_DYNAMIC) { + dyn = (Elf64_Dyn*)(base + pt[i].p_offset); + } + } + + if (!found_vaddr || !dyn) + return; /* Failed */ + + /* + * Fish out the useful bits of the dynamic table. + */ + Elf64_Word *hash = 0; + vdso_info.symstrings = 0; + vdso_info.symtab = 0; + vdso_info.versym = 0; + vdso_info.verdef = 0; + for (i = 0; dyn[i].d_tag != DT_NULL; i++) { + switch (dyn[i].d_tag) { + case DT_STRTAB: + vdso_info.symstrings = (const char *) + ((uintptr_t)dyn[i].d_un.d_ptr + + vdso_info.load_offset); + break; + case DT_SYMTAB: + vdso_info.symtab = (Elf64_Sym *) + ((uintptr_t)dyn[i].d_un.d_ptr + + vdso_info.load_offset); + break; + case DT_HASH: + hash = (Elf64_Word *) + ((uintptr_t)dyn[i].d_un.d_ptr + + vdso_info.load_offset); + break; + case DT_VERSYM: + vdso_info.versym = (Elf64_Versym *) + ((uintptr_t)dyn[i].d_un.d_ptr + + vdso_info.load_offset); + break; + case DT_VERDEF: + vdso_info.verdef = (Elf64_Verdef *) + ((uintptr_t)dyn[i].d_un.d_ptr + + vdso_info.load_offset); + break; + } + } + if (!vdso_info.symstrings || !vdso_info.symtab || !hash) + return; /* Failed */ + + if (!vdso_info.verdef) + vdso_info.versym = 0; + + /* Parse the hash table header. */ + vdso_info.nbucket = hash[0]; + vdso_info.nchain = hash[1]; + vdso_info.bucket = &hash[2]; + vdso_info.chain = &hash[vdso_info.nbucket + 2]; + + /* That's all we need. */ + vdso_info.valid = true; +} + +static bool vdso_match_version(Elf64_Versym ver, + const char *name, Elf64_Word hash) +{ + /* + * This is a helper function to check if the version indexed by + * ver matches name (which hashes to hash). + * + * The version definition table is a mess, and I don't know how + * to do this in better than linear time without allocating memory + * to build an index. I also don't know why the table has + * variable size entries in the first place. + * + * For added fun, I can't find a comprehensible specification of how + * to parse all the weird flags in the table. + * + * So I just parse the whole table every time. + */ + + /* First step: find the version definition */ + ver &= 0x7fff; /* Apparently bit 15 means "hidden" */ + Elf64_Verdef *def = vdso_info.verdef; + while(true) { + if ((def->vd_flags & VER_FLG_BASE) == 0 + && (def->vd_ndx & 0x7fff) == ver) + break; + + if (def->vd_next == 0) + return false; /* No definition. */ + + def = (Elf64_Verdef *)((char *)def + def->vd_next); + } + + /* Now figure out whether it matches. */ + Elf64_Verdaux *aux = (Elf64_Verdaux*)((char *)def + def->vd_aux); + return def->vd_hash == hash + && !strcmp(name, vdso_info.symstrings + aux->vda_name); +} + +void *vdso_sym(const char *version, const char *name) +{ + unsigned long ver_hash; + if (!vdso_info.valid) + return 0; + + ver_hash = elf_hash(version); + Elf64_Word chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket]; + + for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) { + Elf64_Sym *sym = &vdso_info.symtab[chain]; + + /* Check for a defined global or weak function w/ right name. */ + if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC) + continue; + if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL && + ELF64_ST_BIND(sym->st_info) != STB_WEAK) + continue; + if (sym->st_shndx == SHN_UNDEF) + continue; + if (strcmp(name, vdso_info.symstrings + sym->st_name)) + continue; + + /* Check symbol version. */ + if (vdso_info.versym + && !vdso_match_version(vdso_info.versym[chain], + version, ver_hash)) + continue; + + return (void *)(vdso_info.load_offset + sym->st_value); + } + + return 0; +} + +void vdso_init_from_auxv(void *auxv) +{ + Elf64_auxv_t *elf_auxv = auxv; + for (int i = 0; elf_auxv[i].a_type != AT_NULL; i++) + { + if (elf_auxv[i].a_type == AT_SYSINFO_EHDR) { + vdso_init_from_sysinfo_ehdr(elf_auxv[i].a_un.a_val); + return; + } + } + + vdso_info.valid = false; +} diff --git a/Documentation/vDSO/vdso_test.c b/Documentation/vDSO/vdso_test.c new file mode 100644 index 00000000000..fff633432df --- /dev/null +++ b/Documentation/vDSO/vdso_test.c @@ -0,0 +1,111 @@ +/* + * vdso_test.c: Sample code to test parse_vdso.c on x86_64 + * Copyright (c) 2011 Andy Lutomirski + * Subject to the GNU General Public License, version 2 + * + * You can amuse yourself by compiling with: + * gcc -std=gnu99 -nostdlib + * -Os -fno-asynchronous-unwind-tables -flto + * vdso_test.c parse_vdso.c -o vdso_test + * to generate a small binary with no dependencies at all. + */ + +#include <sys/syscall.h> +#include <sys/time.h> +#include <unistd.h> +#include <stdint.h> + +extern void *vdso_sym(const char *version, const char *name); +extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); +extern void vdso_init_from_auxv(void *auxv); + +/* We need a libc functions... */ +int strcmp(const char *a, const char *b) +{ + /* This implementation is buggy: it never returns -1. */ + while (*a || *b) { + if (*a != *b) + return 1; + if (*a == 0 || *b == 0) + return 1; + a++; + b++; + } + + return 0; +} + +/* ...and two syscalls. This is x86_64-specific. */ +static inline long linux_write(int fd, const void *data, size_t len) +{ + + long ret; + asm volatile ("syscall" : "=a" (ret) : "a" (__NR_write), + "D" (fd), "S" (data), "d" (len) : + "cc", "memory", "rcx", + "r8", "r9", "r10", "r11" ); + return ret; +} + +static inline void linux_exit(int code) +{ + asm volatile ("syscall" : : "a" (__NR_exit), "D" (code)); +} + +void to_base10(char *lastdig, uint64_t n) +{ + while (n) { + *lastdig = (n % 10) + '0'; + n /= 10; + lastdig--; + } +} + +__attribute__((externally_visible)) void c_main(void **stack) +{ + /* Parse the stack */ + long argc = (long)*stack; + stack += argc + 2; + + /* Now we're pointing at the environment. Skip it. */ + while(*stack) + stack++; + stack++; + + /* Now we're pointing at auxv. Initialize the vDSO parser. */ + vdso_init_from_auxv((void *)stack); + + /* Find gettimeofday. */ + typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz); + gtod_t gtod = (gtod_t)vdso_sym("LINUX_2.6", "__vdso_gettimeofday"); + + if (!gtod) + linux_exit(1); + + struct timeval tv; + long ret = gtod(&tv, 0); + + if (ret == 0) { + char buf[] = "The time is .000000\n"; + to_base10(buf + 31, tv.tv_sec); + to_base10(buf + 38, tv.tv_usec); + linux_write(1, buf, sizeof(buf) - 1); + } else { + linux_exit(ret); + } + + linux_exit(0); +} + +/* + * This is the real entry point. It passes the initial stack into + * the C entry point. + */ +asm ( + ".text\n" + ".global _start\n" + ".type _start,@function\n" + "_start:\n\t" + "mov %rsp,%rdi\n\t" + "jmp c_main" + ); diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 42542eb802c..b0e4b9cd6a6 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -180,6 +180,19 @@ KVM_CHECK_EXTENSION ioctl() to determine the value for max_vcpus at run-time. If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4 cpus max. +On powerpc using book3s_hv mode, the vcpus are mapped onto virtual +threads in one or more virtual CPU cores. (This is because the +hardware requires all the hardware threads in a CPU core to be in the +same partition.) The KVM_CAP_PPC_SMT capability indicates the number +of vcpus per virtual core (vcore). The vcore id is obtained by +dividing the vcpu id by the number of vcpus per vcore. The vcpus in a +given vcore will always be in the same physical core as each other +(though that might be a different physical core from time to time). +Userspace can control the threading (SMT) mode of the guest by its +allocation of vcpu ids. For example, if userspace wants +single-threaded guest vcpus, it should make all vcpu ids be a multiple +of the number of vcpus per vcore. + 4.8 KVM_GET_DIRTY_LOG (vm ioctl) Capability: basic @@ -1143,15 +1156,10 @@ Assigns an IRQ to a passed-through device. struct kvm_assigned_irq { __u32 assigned_dev_id; - __u32 host_irq; + __u32 host_irq; /* ignored (legacy field) */ __u32 guest_irq; __u32 flags; union { - struct { - __u32 addr_lo; - __u32 addr_hi; - __u32 data; - } guest_msi; __u32 reserved[12]; }; }; @@ -1239,8 +1247,10 @@ Type: vm ioctl Parameters: struct kvm_assigned_msix_nr (in) Returns: 0 on success, -1 on error -Set the number of MSI-X interrupts for an assigned device. This service can -only be called once in the lifetime of an assigned device. +Set the number of MSI-X interrupts for an assigned device. The number is +reset again by terminating the MSI-X assignment of the device via +KVM_DEASSIGN_DEV_IRQ. Calling this service more than once at any earlier +point will fail. struct kvm_assigned_msix_nr { __u32 assigned_dev_id; @@ -1291,6 +1301,135 @@ Returns the tsc frequency of the guest. The unit of the return value is KHz. If the host has unstable tsc this ioctl returns -EIO instead as an error. +4.56 KVM_GET_LAPIC + +Capability: KVM_CAP_IRQCHIP +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_lapic_state (out) +Returns: 0 on success, -1 on error + +#define KVM_APIC_REG_SIZE 0x400 +struct kvm_lapic_state { + char regs[KVM_APIC_REG_SIZE]; +}; + +Reads the Local APIC registers and copies them into the input argument. The +data format and layout are the same as documented in the architecture manual. + +4.57 KVM_SET_LAPIC + +Capability: KVM_CAP_IRQCHIP +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_lapic_state (in) +Returns: 0 on success, -1 on error + +#define KVM_APIC_REG_SIZE 0x400 +struct kvm_lapic_state { + char regs[KVM_APIC_REG_SIZE]; +}; + +Copies the input argument into the the Local APIC registers. The data format +and layout are the same as documented in the architecture manual. + +4.58 KVM_IOEVENTFD + +Capability: KVM_CAP_IOEVENTFD +Architectures: all +Type: vm ioctl +Parameters: struct kvm_ioeventfd (in) +Returns: 0 on success, !0 on error + +This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address +within the guest. A guest write in the registered address will signal the +provided event instead of triggering an exit. + +struct kvm_ioeventfd { + __u64 datamatch; + __u64 addr; /* legal pio/mmio address */ + __u32 len; /* 1, 2, 4, or 8 bytes */ + __s32 fd; + __u32 flags; + __u8 pad[36]; +}; + +The following flags are defined: + +#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) +#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) +#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) + +If datamatch flag is set, the event will be signaled only if the written value +to the registered address is equal to datamatch in struct kvm_ioeventfd. + +4.62 KVM_CREATE_SPAPR_TCE + +Capability: KVM_CAP_SPAPR_TCE +Architectures: powerpc +Type: vm ioctl +Parameters: struct kvm_create_spapr_tce (in) +Returns: file descriptor for manipulating the created TCE table + +This creates a virtual TCE (translation control entry) table, which +is an IOMMU for PAPR-style virtual I/O. It is used to translate +logical addresses used in virtual I/O into guest physical addresses, +and provides a scatter/gather capability for PAPR virtual I/O. + +/* for KVM_CAP_SPAPR_TCE */ +struct kvm_create_spapr_tce { + __u64 liobn; + __u32 window_size; +}; + +The liobn field gives the logical IO bus number for which to create a +TCE table. The window_size field specifies the size of the DMA window +which this TCE table will translate - the table will contain one 64 +bit TCE entry for every 4kiB of the DMA window. + +When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE +table has been created using this ioctl(), the kernel will handle it +in real mode, updating the TCE table. H_PUT_TCE calls for other +liobns will cause a vm exit and must be handled by userspace. + +The return value is a file descriptor which can be passed to mmap(2) +to map the created TCE table into userspace. This lets userspace read +the entries written by kernel-handled H_PUT_TCE calls, and also lets +userspace update the TCE table directly which is useful in some +circumstances. + +4.63 KVM_ALLOCATE_RMA + +Capability: KVM_CAP_PPC_RMA +Architectures: powerpc +Type: vm ioctl +Parameters: struct kvm_allocate_rma (out) +Returns: file descriptor for mapping the allocated RMA + +This allocates a Real Mode Area (RMA) from the pool allocated at boot +time by the kernel. An RMA is a physically-contiguous, aligned region +of memory used on older POWER processors to provide the memory which +will be accessed by real-mode (MMU off) accesses in a KVM guest. +POWER processors support a set of sizes for the RMA that usually +includes 64MB, 128MB, 256MB and some larger powers of two. + +/* for KVM_ALLOCATE_RMA */ +struct kvm_allocate_rma { + __u64 rma_size; +}; + +The return value is a file descriptor which can be passed to mmap(2) +to map the allocated RMA into userspace. The mapped area can then be +passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the +RMA for a virtual machine. The size of the RMA in bytes (which is +fixed at host kernel boot time) is returned in the rma_size field of +the argument structure. + +The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl +is supported; 2 if the processor requires all virtual machines to have +an RMA, or 1 if the processor can use an RMA but doesn't require it, +because it supports the Virtual RMA (VRMA) facility. + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by @@ -1473,6 +1612,23 @@ Userspace can now handle the hypercall and when it's done modify the gprs as necessary. Upon guest entry all guest GPRs will then be replaced by the values in this struct. + /* KVM_EXIT_PAPR_HCALL */ + struct { + __u64 nr; + __u64 ret; + __u64 args[9]; + } papr_hcall; + +This is used on 64-bit PowerPC when emulating a pSeries partition, +e.g. with the 'pseries' machine type in qemu. It occurs when the +guest does a hypercall using the 'sc 1' instruction. The 'nr' field +contains the hypercall number (from the guest R3), and 'args' contains +the arguments (from the guest R4 - R12). Userspace should put the +return code in 'ret' and any extra returned values in args[]. +The possible hypercalls are defined in the Power Architecture Platform +Requirements (PAPR) document available from www.power.org (free +developer registration required to access it). + /* Fix the size of the union. */ char padding[256]; }; diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index f46aa58389c..5dc972c09b5 100644 --- a/Documentation/virtual/kvm/mmu.txt +++ b/Documentation/virtual/kvm/mmu.txt @@ -165,6 +165,10 @@ Shadow pages contain the following information: Contains the value of efer.nxe for which the page is valid. role.cr0_wp: Contains the value of cr0.wp for which the page is valid. + role.smep_andnot_wp: + Contains the value of cr4.smep && !cr0.wp for which the page is valid + (pages for which this is true are different from other pages; see the + treatment of cr0.wp=0 below). gfn: Either the guest page table containing the translations shadowed by this page, or the base page frame for linear translations. See role.direct. @@ -317,6 +321,20 @@ on fault type: (user write faults generate a #PF) +In the first case there is an additional complication if CR4.SMEP is +enabled: since we've turned the page into a kernel page, the kernel may now +execute it. We handle this by also setting spte.nx. If we get a user +fetch or read fault, we'll change spte.u=1 and spte.nx=gpte.nx back. + +To prevent an spte that was converted into a kernel page with cr0.wp=0 +from being written by the kernel after cr0.wp has changed to 1, we make +the value of cr0.wp part of the page role. This means that an spte created +with one value of cr0.wp cannot be used when cr0.wp has a different value - +it will simply be missed by the shadow page lookup code. A similar issue +exists when an spte created with cr0.wp=0 and cr4.smep=0 is used after +changing cr4.smep to 1. To avoid this, the value of !cr0.wp && cr4.smep +is also made a part of the page role. + Large pages =========== diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt index d079aed27e0..50317809113 100644 --- a/Documentation/virtual/kvm/msr.txt +++ b/Documentation/virtual/kvm/msr.txt @@ -185,3 +185,37 @@ MSR_KVM_ASYNC_PF_EN: 0x4b564d02 Currently type 2 APF will be always delivered on the same vcpu as type 1 was, but guest should not rely on that. + +MSR_KVM_STEAL_TIME: 0x4b564d03 + + data: 64-byte alignment physical address of a memory area which must be + in guest RAM, plus an enable bit in bit 0. This memory is expected to + hold a copy of the following structure: + + struct kvm_steal_time { + __u64 steal; + __u32 version; + __u32 flags; + __u32 pad[12]; + } + + whose data will be filled in by the hypervisor periodically. Only one + write, or registration, is needed for each VCPU. The interval between + updates of this structure is arbitrary and implementation-dependent. + The hypervisor may update this structure at any time it sees fit until + anything with bit0 == 0 is written to it. Guest is required to make sure + this structure is initialized to zero. + + Fields have the following meanings: + + version: a sequence counter. In other words, guest has to check + this field before and after grabbing time information and make + sure they are both equal and even. An odd version indicates an + in-progress update. + + flags: At this point, always zero. May be used to indicate + changes in this structure in the future. + + steal: the amount of time in which this vCPU did not run, in + nanoseconds. Time during which the vcpu is idle, will not be + reported as steal time. diff --git a/Documentation/virtual/kvm/nested-vmx.txt b/Documentation/virtual/kvm/nested-vmx.txt new file mode 100644 index 00000000000..8ed937de116 --- /dev/null +++ b/Documentation/virtual/kvm/nested-vmx.txt @@ -0,0 +1,251 @@ +Nested VMX +========== + +Overview +--------- + +On Intel processors, KVM uses Intel's VMX (Virtual-Machine eXtensions) +to easily and efficiently run guest operating systems. Normally, these guests +*cannot* themselves be hypervisors running their own guests, because in VMX, +guests cannot use VMX instructions. + +The "Nested VMX" feature adds this missing capability - of running guest +hypervisors (which use VMX) with their own nested guests. It does so by +allowing a guest to use VMX instructions, and correctly and efficiently +emulating them using the single level of VMX available in the hardware. + +We describe in much greater detail the theory behind the nested VMX feature, +its implementation and its performance characteristics, in the OSDI 2010 paper +"The Turtles Project: Design and Implementation of Nested Virtualization", +available at: + + http://www.usenix.org/events/osdi10/tech/full_papers/Ben-Yehuda.pdf + + +Terminology +----------- + +Single-level virtualization has two levels - the host (KVM) and the guests. +In nested virtualization, we have three levels: The host (KVM), which we call +L0, the guest hypervisor, which we call L1, and its nested guest, which we +call L2. + + +Known limitations +----------------- + +The current code supports running Linux guests under KVM guests. +Only 64-bit guest hypervisors are supported. + +Additional patches for running Windows under guest KVM, and Linux under +guest VMware server, and support for nested EPT, are currently running in +the lab, and will be sent as follow-on patchsets. + + +Running nested VMX +------------------ + +The nested VMX feature is disabled by default. It can be enabled by giving +the "nested=1" option to the kvm-intel module. + +No modifications are required to user space (qemu). However, qemu's default +emulated CPU type (qemu64) does not list the "VMX" CPU feature, so it must be +explicitly enabled, by giving qemu one of the following options: + + -cpu host (emulated CPU has all features of the real CPU) + + -cpu qemu64,+vmx (add just the vmx feature to a named CPU type) + + +ABIs +---- + +Nested VMX aims to present a standard and (eventually) fully-functional VMX +implementation for the a guest hypervisor to use. As such, the official +specification of the ABI that it provides is Intel's VMX specification, +namely volume 3B of their "Intel 64 and IA-32 Architectures Software +Developer's Manual". Not all of VMX's features are currently fully supported, +but the goal is to eventually support them all, starting with the VMX features +which are used in practice by popular hypervisors (KVM and others). + +As a VMX implementation, nested VMX presents a VMCS structure to L1. +As mandated by the spec, other than the two fields revision_id and abort, +this structure is *opaque* to its user, who is not supposed to know or care +about its internal structure. Rather, the structure is accessed through the +VMREAD and VMWRITE instructions. +Still, for debugging purposes, KVM developers might be interested to know the +internals of this structure; This is struct vmcs12 from arch/x86/kvm/vmx.c. + +The name "vmcs12" refers to the VMCS that L1 builds for L2. In the code we +also have "vmcs01", the VMCS that L0 built for L1, and "vmcs02" is the VMCS +which L0 builds to actually run L2 - how this is done is explained in the +aforementioned paper. + +For convenience, we repeat the content of struct vmcs12 here. If the internals +of this structure changes, this can break live migration across KVM versions. +VMCS12_REVISION (from vmx.c) should be changed if struct vmcs12 or its inner +struct shadow_vmcs is ever changed. + + typedef u64 natural_width; + struct __packed vmcs12 { + /* According to the Intel spec, a VMCS region must start with + * these two user-visible fields */ + u32 revision_id; + u32 abort; + + u32 launch_state; /* set to 0 by VMCLEAR, to 1 by VMLAUNCH */ + u32 padding[7]; /* room for future expansion */ + + u64 io_bitmap_a; + u64 io_bitmap_b; + u64 msr_bitmap; + u64 vm_exit_msr_store_addr; + u64 vm_exit_msr_load_addr; + u64 vm_entry_msr_load_addr; + u64 tsc_offset; + u64 virtual_apic_page_addr; + u64 apic_access_addr; + u64 ept_pointer; + u64 guest_physical_address; + u64 vmcs_link_pointer; + u64 guest_ia32_debugctl; + u64 guest_ia32_pat; + u64 guest_ia32_efer; + u64 guest_pdptr0; + u64 guest_pdptr1; + u64 guest_pdptr2; + u64 guest_pdptr3; + u64 host_ia32_pat; + u64 host_ia32_efer; + u64 padding64[8]; /* room for future expansion */ + natural_width cr0_guest_host_mask; + natural_width cr4_guest_host_mask; + natural_width cr0_read_shadow; + natural_width cr4_read_shadow; + natural_width cr3_target_value0; + natural_width cr3_target_value1; + natural_width cr3_target_value2; + natural_width cr3_target_value3; + natural_width exit_qualification; + natural_width guest_linear_address; + natural_width guest_cr0; + natural_width guest_cr3; + natural_width guest_cr4; + natural_width guest_es_base; + natural_width guest_cs_base; + natural_width guest_ss_base; + natural_width guest_ds_base; + natural_width guest_fs_base; + natural_width guest_gs_base; + natural_width guest_ldtr_base; + natural_width guest_tr_base; + natural_width guest_gdtr_base; + natural_width guest_idtr_base; + natural_width guest_dr7; + natural_width guest_rsp; + natural_width guest_rip; + natural_width guest_rflags; + natural_width guest_pending_dbg_exceptions; + natural_width guest_sysenter_esp; + natural_width guest_sysenter_eip; + natural_width host_cr0; + natural_width host_cr3; + natural_width host_cr4; + natural_width host_fs_base; + natural_width host_gs_base; + natural_width host_tr_base; + natural_width host_gdtr_base; + natural_width host_idtr_base; + natural_width host_ia32_sysenter_esp; + natural_width host_ia32_sysenter_eip; + natural_width host_rsp; + natural_width host_rip; + natural_width paddingl[8]; /* room for future expansion */ + u32 pin_based_vm_exec_control; + u32 cpu_based_vm_exec_control; + u32 exception_bitmap; + u32 page_fault_error_code_mask; + u32 page_fault_error_code_match; + u32 cr3_target_count; + u32 vm_exit_controls; + u32 vm_exit_msr_store_count; + u32 vm_exit_msr_load_count; + u32 vm_entry_controls; + u32 vm_entry_msr_load_count; + u32 vm_entry_intr_info_field; + u32 vm_entry_exception_error_code; + u32 vm_entry_instruction_len; + u32 tpr_threshold; + u32 secondary_vm_exec_control; + u32 vm_instruction_error; + u32 vm_exit_reason; + u32 vm_exit_intr_info; + u32 vm_exit_intr_error_code; + u32 idt_vectoring_info_field; + u32 idt_vectoring_error_code; + u32 vm_exit_instruction_len; + u32 vmx_instruction_info; + u32 guest_es_limit; + u32 guest_cs_limit; + u32 guest_ss_limit; + u32 guest_ds_limit; + u32 guest_fs_limit; + u32 guest_gs_limit; + u32 guest_ldtr_limit; + u32 guest_tr_limit; + u32 guest_gdtr_limit; + u32 guest_idtr_limit; + u32 guest_es_ar_bytes; + u32 guest_cs_ar_bytes; + u32 guest_ss_ar_bytes; + u32 guest_ds_ar_bytes; + u32 guest_fs_ar_bytes; + u32 guest_gs_ar_bytes; + u32 guest_ldtr_ar_bytes; + u32 guest_tr_ar_bytes; + u32 guest_interruptibility_info; + u32 guest_activity_state; + u32 guest_sysenter_cs; + u32 host_ia32_sysenter_cs; + u32 padding32[8]; /* room for future expansion */ + u16 virtual_processor_id; + u16 guest_es_selector; + u16 guest_cs_selector; + u16 guest_ss_selector; + u16 guest_ds_selector; + u16 guest_fs_selector; + u16 guest_gs_selector; + u16 guest_ldtr_selector; + u16 guest_tr_selector; + u16 host_es_selector; + u16 host_cs_selector; + u16 host_ss_selector; + u16 host_ds_selector; + u16 host_fs_selector; + u16 host_gs_selector; + u16 host_tr_selector; + }; + + +Authors +------- + +These patches were written by: + Abel Gordon, abelg <at> il.ibm.com + Nadav Har'El, nyh <at> il.ibm.com + Orit Wasserman, oritw <at> il.ibm.com + Ben-Ami Yassor, benami <at> il.ibm.com + Muli Ben-Yehuda, muli <at> il.ibm.com + +With contributions by: + Anthony Liguori, aliguori <at> us.ibm.com + Mike Day, mdday <at> us.ibm.com + Michael Factor, factor <at> il.ibm.com + Zvi Dubitzky, dubi <at> il.ibm.com + +And valuable reviews by: + Avi Kivity, avi <at> redhat.com + Gleb Natapov, gleb <at> redhat.com + Marcelo Tosatti, mtosatti <at> redhat.com + Kevin Tian, kevin.tian <at> intel.com + and others. diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt index 3ab969c5904..2b7ce190cde 100644 --- a/Documentation/virtual/kvm/ppc-pv.txt +++ b/Documentation/virtual/kvm/ppc-pv.txt @@ -68,9 +68,11 @@ page that contains parts of supervisor visible register state. The guest can map this shared page using the KVM hypercall KVM_HC_PPC_MAP_MAGIC_PAGE. With this hypercall issued the guest always gets the magic page mapped at the -desired location in effective and physical address space. For now, we always -map the page to -4096. This way we can access it using absolute load and store -functions. The following instruction reads the first field of the magic page: +desired location. The first parameter indicates the effective address when the +MMU is enabled. The second parameter indicates the address in real mode, if +applicable to the target. For now, we always map the page to -4096. This way we +can access it using absolute load and store functions. The following +instruction reads the first field of the magic page: ld rX, -4096(0) diff --git a/Documentation/virtual/lguest/lguest.c b/Documentation/virtual/lguest/lguest.c index cd9d6af61d0..043bd7df313 100644 --- a/Documentation/virtual/lguest/lguest.c +++ b/Documentation/virtual/lguest/lguest.c @@ -51,7 +51,7 @@ #include <asm/bootparam.h> #include "../../../include/linux/lguest_launcher.h" /*L:110 - * We can ignore the 42 include files we need for this program, but I do want + * We can ignore the 43 include files we need for this program, but I do want * to draw attention to the use of kernel-style types. * * As Linus said, "C is a Spartan language, and so should your naming be." I @@ -65,7 +65,6 @@ typedef uint16_t u16; typedef uint8_t u8; /*:*/ -#define PAGE_PRESENT 0x7 /* Present, RW, Execute */ #define BRIDGE_PFX "bridge:" #ifndef SIOCBRADDIF #define SIOCBRADDIF 0x89a2 /* add interface to bridge */ @@ -861,8 +860,10 @@ static void console_output(struct virtqueue *vq) /* writev can return a partial write, so we loop here. */ while (!iov_empty(iov, out)) { int len = writev(STDOUT_FILENO, iov, out); - if (len <= 0) - err(1, "Write to stdout gave %i", len); + if (len <= 0) { + warn("Write to stdout gave %i (%d)", len, errno); + break; + } iov_consume(iov, out, len); } @@ -898,7 +899,7 @@ static void net_output(struct virtqueue *vq) * same format: what a coincidence! */ if (writev(net_info->tunfd, iov, out) < 0) - errx(1, "Write to tun failed?"); + warnx("Write to tun failed (%d)?", errno); /* * Done with that one; wait_for_vq_desc() will send the interrupt if @@ -955,7 +956,7 @@ static void net_input(struct virtqueue *vq) */ len = readv(net_info->tunfd, iov, in); if (len <= 0) - err(1, "Failed to read from tun."); + warn("Failed to read from tun (%d).", errno); /* * Mark that packet buffer as used, but don't interrupt here. We want @@ -1093,9 +1094,10 @@ static void update_device_status(struct device *dev) warnx("Device %s configuration FAILED", dev->name); if (dev->running) reset_device(dev); - } else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) { - if (!dev->running) - start_device(dev); + } else { + if (dev->running) + err(1, "Device %s features finalized twice", dev->name); + start_device(dev); } } @@ -1120,25 +1122,11 @@ static void handle_output(unsigned long addr) return; } - /* - * Devices *can* be used before status is set to DRIVER_OK. - * The original plan was that they would never do this: they - * would always finish setting up their status bits before - * actually touching the virtqueues. In practice, we allowed - * them to, and they do (eg. the disk probes for partition - * tables as part of initialization). - * - * If we see this, we start the device: once it's running, we - * expect the device to catch all the notifications. - */ + /* Devices should not be used before features are finalized. */ for (vq = i->vq; vq; vq = vq->next) { if (addr != vq->config.pfn*getpagesize()) continue; - if (i->running) - errx(1, "Notification on running %s", i->name); - /* This just calls create_thread() for each virtqueue */ - start_device(i); - return; + errx(1, "Notification on %s before setup!", i->name); } } @@ -1370,7 +1358,7 @@ static void setup_console(void) * --sharenet=<name> option which opens or creates a named pipe. This can be * used to send packets to another guest in a 1:1 manner. * - * More sopisticated is to use one of the tools developed for project like UML + * More sophisticated is to use one of the tools developed for project like UML * to do networking. * * Faster is to do virtio bonding in kernel. Doing this 1:1 would be @@ -1380,7 +1368,7 @@ static void setup_console(void) * multiple inter-guest channels behind one interface, although it would * require some manner of hotplugging new virtio channels. * - * Finally, we could implement a virtio network switch in the kernel. + * Finally, we could use a virtio network switch in the kernel, ie. vhost. :*/ static u32 str2ip(const char *ipaddr) @@ -2017,10 +2005,7 @@ int main(int argc, char *argv[]) /* Tell the entry path not to try to reload segment registers. */ boot->hdr.loadflags |= KEEP_SEGMENTS; - /* - * We tell the kernel to initialize the Guest: this returns the open - * /dev/lguest file descriptor. - */ + /* We tell the kernel to initialize the Guest. */ tell_kernel(start); /* Ensure that we terminate if a device-servicing child dies. */ diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt index 9b7221a86df..7c3a8801b7c 100644 --- a/Documentation/x86/boot.txt +++ b/Documentation/x86/boot.txt @@ -674,7 +674,7 @@ Protocol: 2.10+ Field name: init_size Type: read -Offset/size: 0x25c/4 +Offset/size: 0x260/4 This field indicates the amount of linear contiguous memory starting at the kernel runtime start address that the kernel needs before it diff --git a/Documentation/x86/entry_64.txt b/Documentation/x86/entry_64.txt new file mode 100644 index 00000000000..7869f14d055 --- /dev/null +++ b/Documentation/x86/entry_64.txt @@ -0,0 +1,98 @@ +This file documents some of the kernel entries in +arch/x86/kernel/entry_64.S. A lot of this explanation is adapted from +an email from Ingo Molnar: + +http://lkml.kernel.org/r/<20110529191055.GC9835%40elte.hu> + +The x86 architecture has quite a few different ways to jump into +kernel code. Most of these entry points are registered in +arch/x86/kernel/traps.c and implemented in arch/x86/kernel/entry_64.S +and arch/x86/ia32/ia32entry.S. + +The IDT vector assignments are listed in arch/x86/include/irq_vectors.h. + +Some of these entries are: + + - system_call: syscall instruction from 64-bit code. + + - ia32_syscall: int 0x80 from 32-bit or 64-bit code; compat syscall + either way. + + - ia32_syscall, ia32_sysenter: syscall and sysenter from 32-bit + code + + - interrupt: An array of entries. Every IDT vector that doesn't + explicitly point somewhere else gets set to the corresponding + value in interrupts. These point to a whole array of + magically-generated functions that make their way to do_IRQ with + the interrupt number as a parameter. + + - emulate_vsyscall: int 0xcc, a special non-ABI entry used by + vsyscall emulation. + + - APIC interrupts: Various special-purpose interrupts for things + like TLB shootdown. + + - Architecturally-defined exceptions like divide_error. + +There are a few complexities here. The different x86-64 entries +have different calling conventions. The syscall and sysenter +instructions have their own peculiar calling conventions. Some of +the IDT entries push an error code onto the stack; others don't. +IDT entries using the IST alternative stack mechanism need their own +magic to get the stack frames right. (You can find some +documentation in the AMD APM, Volume 2, Chapter 8 and the Intel SDM, +Volume 3, Chapter 6.) + +Dealing with the swapgs instruction is especially tricky. Swapgs +toggles whether gs is the kernel gs or the user gs. The swapgs +instruction is rather fragile: it must nest perfectly and only in +single depth, it should only be used if entering from user mode to +kernel mode and then when returning to user-space, and precisely +so. If we mess that up even slightly, we crash. + +So when we have a secondary entry, already in kernel mode, we *must +not* use SWAPGS blindly - nor must we forget doing a SWAPGS when it's +not switched/swapped yet. + +Now, there's a secondary complication: there's a cheap way to test +which mode the CPU is in and an expensive way. + +The cheap way is to pick this info off the entry frame on the kernel +stack, from the CS of the ptregs area of the kernel stack: + + xorl %ebx,%ebx + testl $3,CS+8(%rsp) + je error_kernelspace + SWAPGS + +The expensive (paranoid) way is to read back the MSR_GS_BASE value +(which is what SWAPGS modifies): + + movl $1,%ebx + movl $MSR_GS_BASE,%ecx + rdmsr + testl %edx,%edx + js 1f /* negative -> in kernel */ + SWAPGS + xorl %ebx,%ebx +1: ret + +and the whole paranoid non-paranoid macro complexity is about whether +to suffer that RDMSR cost. + +If we are at an interrupt or user-trap/gate-alike boundary then we can +use the faster check: the stack will be a reliable indicator of +whether SWAPGS was already done: if we see that we are a secondary +entry interrupting kernel mode execution, then we know that the GS +base has already been switched. If it says that we interrupted +user-space execution then we must do the SWAPGS. + +But if we are in an NMI/MCE/DEBUG/whatever super-atomic entry context, +which might have triggered right after a normal entry wrote CS to the +stack but before we executed SWAPGS, then the only safe way to check +for GS is the slower method: the RDMSR. + +So we try only to mark those entry methods 'paranoid' that absolutely +need the more expensive check for the GS base - and we generate all +'normal' entry points with the regular (faster) entry macros. diff --git a/Documentation/zh_CN/SubmitChecklist b/Documentation/zh_CN/SubmitChecklist index 951415bbab0..4c741d6bc04 100644 --- a/Documentation/zh_CN/SubmitChecklist +++ b/Documentation/zh_CN/SubmitChecklist @@ -67,7 +67,7 @@ Linux内核提交清单 12：已经通过CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES, - CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_SPINLOCK_SLEEP测试，并且同时都 + CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_ATOMIC_SLEEP测试，并且同时都 使能。 13：已经都构建并且使用或者不使用 CONFIG_SMP 和 CONFIG_PREEMPT测试执行时间。 |