diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/cputopology.txt | 41 | ||||
| -rw-r--r-- | Documentation/driver-model/overview.txt | 57 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/configfs/configfs_example.c | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/ocfs2.txt | 1 | ||||
| -rw-r--r-- | Documentation/hwmon/f71805f | 105 | ||||
| -rw-r--r-- | Documentation/hwmon/it87 | 2 | ||||
| -rw-r--r-- | Documentation/hwmon/sysfs-interface | 18 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-sis96x (renamed from Documentation/i2c/busses/i2c-sis69x) | 4 | ||||
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 17 | ||||
| -rw-r--r-- | Documentation/parport-lowlevel.txt | 8 | ||||
| -rw-r--r-- | Documentation/pci-error-recovery.txt | 472 | ||||
| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 8 | ||||
| -rw-r--r-- | Documentation/spi/butterfly | 23 | ||||
| -rw-r--r-- | Documentation/unshare.txt | 295 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.cx88 | 2 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.saa7134 | 6 | ||||
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 12 |
18 files changed, 871 insertions, 211 deletions
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt new file mode 100644 index 00000000000..ff280e2e161 --- /dev/null +++ b/Documentation/cputopology.txt @@ -0,0 +1,41 @@ + +Export cpu topology info by sysfs. Items (attributes) are similar +to /proc/cpuinfo. + +1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: +represent the physical package id of cpu X; +2) /sys/devices/system/cpu/cpuX/topology/core_id: +represent the cpu core id to cpu X; +3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: +represent the thread siblings to cpu X in the same core; +4) /sys/devices/system/cpu/cpuX/topology/core_siblings: +represent the thread siblings to cpu X in the same physical package; + +To implement it in an architecture-neutral way, a new source file, +driver/base/topology.c, is to export the 5 attributes. + +If one architecture wants to support this feature, it just needs to +implement 4 defines, typically in file include/asm-XXX/topology.h. +The 4 defines are: +#define topology_physical_package_id(cpu) +#define topology_core_id(cpu) +#define topology_thread_siblings(cpu) +#define topology_core_siblings(cpu) + +The type of **_id is int. +The type of siblings is cpumask_t. + +To be consistent on all architectures, the 4 attributes should have +deafult values if their values are unavailable. Below is the rule. +1) physical_package_id: If cpu has no physical package id, -1 is the +default value. +2) core_id: If cpu doesn't support multi-core, its core id is 0. +3) thread_siblings: Just include itself, if the cpu doesn't support +HT/multi-thread. +4) core_siblings: Just include itself, if the cpu doesn't support +multi-core and HT/Multi-thread. + +So be careful when declaring the 4 defines in include/asm-XXX/topology.h. + +If an attribute isn't defined on an architecture, it won't be exported. + diff --git a/Documentation/driver-model/overview.txt b/Documentation/driver-model/overview.txt index 44662735cf8..ac4a7a737e4 100644 --- a/Documentation/driver-model/overview.txt +++ b/Documentation/driver-model/overview.txt @@ -1,50 +1,43 @@ The Linux Kernel Device Model -Patrick Mochel <mochel@osdl.org> +Patrick Mochel <mochel@digitalimplant.org> -26 August 2002 +Drafted 26 August 2002 +Updated 31 January 2006 Overview ~~~~~~~~ -This driver model is a unification of all the current, disparate driver models -that are currently in the kernel. It is intended to augment the +The Linux Kernel Driver Model is a unification of all the disparate driver +models that were previously used in the kernel. It is intended to augment the bus-specific drivers for bridges and devices by consolidating a set of data and operations into globally accessible data structures. -Current driver models implement some sort of tree-like structure (sometimes -just a list) for the devices they control. But, there is no linkage between -the different bus types. +Traditional driver models implemented some sort of tree-like structure +(sometimes just a list) for the devices they control. There wasn't any +uniformity across the different bus types. -A common data structure can provide this linkage with little overhead: when a -bus driver discovers a particular device, it can insert it into the global -tree as well as its local tree. In fact, the local tree becomes just a subset -of the global tree. - -Common data fields can also be moved out of the local bus models into the -global model. Some of the manipulations of these fields can also be -consolidated. Most likely, manipulation functions will become a set -of helper functions, which the bus drivers wrap around to include any -bus-specific items. - -The common device and bridge interface currently reflects the goals of the -modern PC: namely the ability to do seamless Plug and Play, power management, -and hot plug. (The model dictated by Intel and Microsoft (read: ACPI) ensures -us that any device in the system may fit any of these criteria.) - -In reality, not every bus will be able to support such operations. But, most -buses will support a majority of those operations, and all future buses will. -In other words, a bus that doesn't support an operation is the exception, -instead of the other way around. +The current driver model provides a comon, uniform data model for describing +a bus and the devices that can appear under the bus. The unified bus +model includes a set of common attributes which all busses carry, and a set +of common callbacks, such as device discovery during bus probing, bus +shutdown, bus power management, etc. +The common device and bridge interface reflects the goals of the modern +computer: namely the ability to do seamless device "plug and play", power +management, and hot plug. In particular, the model dictated by Intel and +Microsoft (namely ACPI) ensures that almost every device on almost any bus +on an x86-compatible system can work within this paradigm. Of course, +not every bus is able to support all such operations, although most +buses support a most of those operations. Downstream Access ~~~~~~~~~~~~~~~~~ Common data fields have been moved out of individual bus layers into a common -data structure. But, these fields must still be accessed by the bus layers, +data structure. These fields must still be accessed by the bus layers, and sometimes by the device-specific drivers. Other bus layers are encouraged to do what has been done for the PCI layer. @@ -53,7 +46,7 @@ struct pci_dev now looks like this: struct pci_dev { ... - struct device device; + struct device dev; }; Note first that it is statically allocated. This means only one allocation on @@ -64,9 +57,9 @@ the two. The PCI bus layer freely accesses the fields of struct device. It knows about the structure of struct pci_dev, and it should know the structure of struct -device. PCI devices that have been converted generally do not touch the fields -of struct device. More precisely, device-specific drivers should not touch -fields of struct device unless there is a strong compelling reason to do so. +device. Individual PCI device drivers that have been converted the the current +driver model generally do not and should not touch the fields of struct device, +unless there is a strong compelling reason to do so. This abstraction is prevention of unnecessary pain during transitional phases. If the name of the field changes or is removed, then every downstream driver diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 4d4897c8ef9..b730d765b52 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -162,3 +162,12 @@ What: pci_module_init(driver) When: January 2007 Why: Is replaced by pci_register_driver(pci_driver). Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de> + +--------------------------- + +What: I2C interface of the it87 driver +When: January 2007 +Why: The ISA interface is faster and should be always available. The I2C + probing is also known to cause trouble in at least one case (see + bug #5889.) +Who: Jean Delvare <khali@linux-fr.org> diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example.c index f3c6e4946f9..3d4713a6c20 100644 --- a/Documentation/filesystems/configfs/configfs_example.c +++ b/Documentation/filesystems/configfs/configfs_example.c @@ -320,6 +320,7 @@ static struct config_item_type simple_children_type = { .ct_item_ops = &simple_children_item_ops, .ct_group_ops = &simple_children_group_ops, .ct_attrs = simple_children_attrs, + .ct_owner = THIS_MODULE, }; static struct configfs_subsystem simple_children_subsys = { @@ -403,6 +404,7 @@ static struct config_item_type group_children_type = { .ct_item_ops = &group_children_item_ops, .ct_group_ops = &group_children_group_ops, .ct_attrs = group_children_attrs, + .ct_owner = THIS_MODULE, }; static struct configfs_subsystem group_children_subsys = { diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt index f2595caf052..4389c684a80 100644 --- a/Documentation/filesystems/ocfs2.txt +++ b/Documentation/filesystems/ocfs2.txt @@ -35,6 +35,7 @@ Features which OCFS2 does not support yet: be cluster coherent. - quotas - cluster aware flock + - cluster aware lockf - Directory change notification (F_NOTIFY) - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease) - POSIX ACLs diff --git a/Documentation/hwmon/f71805f b/Documentation/hwmon/f71805f new file mode 100644 index 00000000000..28c5b7d1eb9 --- /dev/null +++ b/Documentation/hwmon/f71805f @@ -0,0 +1,105 @@ +Kernel driver f71805f +===================== + +Supported chips: + * Fintek F71805F/FG + Prefix: 'f71805f' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Provided by Fintek on request + +Author: Jean Delvare <khali@linux-fr.org> + +Thanks to Denis Kieft from Barracuda Networks for the donation of a +test system (custom Jetway K8M8MS motherboard, with CPU and RAM) and +for providing initial documentation. + +Thanks to Kris Chen from Fintek for answering technical questions and +providing additional documentation. + +Thanks to Chris Lin from Jetway for providing wiring schematics and +anwsering technical questions. + + +Description +----------- + +The Fintek F71805F/FG Super I/O chip includes complete hardware monitoring +capabilities. It can monitor up to 9 voltages (counting its own power +source), 3 fans and 3 temperature sensors. + +This chip also has fan controlling features, using either DC or PWM, in +three different modes (one manual, two automatic). The driver doesn't +support these features yet. + +The driver assumes that no more than one chip is present, which seems +reasonable. + + +Voltage Monitoring +------------------ + +Voltages are sampled by an 8-bit ADC with a LSB of 8 mV. The supported +range is thus from 0 to 2.040 V. Voltage values outside of this range +need external resistors. An exception is in0, which is used to monitor +the chip's own power source (+3.3V), and is divided internally by a +factor 2. + +The two LSB of the voltage limit registers are not used (always 0), so +you can only set the limits in steps of 32 mV (before scaling). + +The wirings and resistor values suggested by Fintek are as follow: + + pin expected + name use R1 R2 divider raw val. + +in0 VCC VCC3.3V int. int. 2.00 1.65 V +in1 VIN1 VTT1.2V 10K - 1.00 1.20 V +in2 VIN2 VRAM 100K 100K 2.00 ~1.25 V (1) +in3 VIN3 VCHIPSET 47K 100K 1.47 2.24 V (2) +in4 VIN4 VCC5V 200K 47K 5.25 0.95 V +in5 VIN5 +12V 200K 20K 11.00 1.05 V +in6 VIN6 VCC1.5V 10K - 1.00 1.50 V +in7 VIN7 VCORE 10K - 1.00 ~1.40 V (1) +in8 VIN8 VSB5V 200K 47K 1.00 0.95 V + +(1) Depends on your hardware setup. +(2) Obviously not correct, swapping R1 and R2 would make more sense. + +These values can be used as hints at best, as motherboard manufacturers +are free to use a completely different setup. As a matter of fact, the +Jetway K8M8MS uses a significantly different setup. You will have to +find out documentation about your own motherboard, and edit sensors.conf +accordingly. + +Each voltage measured has associated low and high limits, each of which +triggers an alarm when crossed. + + +Fan Monitoring +-------------- + +Fan rotation speeds are reported as 12-bit values from a gated clock +signal. Speeds down to 366 RPM can be measured. There is no theoretical +high limit, but values over 6000 RPM seem to cause problem. The effective +resolution is much lower than you would expect, the step between different +register values being 10 rather than 1. + +The chip assumes 2 pulse-per-revolution fans. + +An alarm is triggered if the rotation speed drops below a programmable +limit or is too low to be measured. + + +Temperature Monitoring +---------------------- + +Temperatures are reported in degrees Celsius. Each temperature measured +has a high limit, those crossing triggers an alarm. There is an associated +hysteresis value, below which the temperature has to drop before the +alarm is cleared. + +All temperature channels are external, there is no embedded temperature +sensor. Each channel can be used for connecting either a thermal diode +or a thermistor. The driver reports the currently selected mode, but +doesn't allow changing it. In theory, the BIOS should have configured +everything properly. diff --git a/Documentation/hwmon/it87 b/Documentation/hwmon/it87 index 7f42e441c64..9555be1ed99 100644 --- a/Documentation/hwmon/it87 +++ b/Documentation/hwmon/it87 @@ -9,7 +9,7 @@ Supported chips: http://www.ite.com.tw/ * IT8712F Prefix: 'it8712' - Addresses scanned: I2C 0x28 - 0x2f + Addresses scanned: I2C 0x2d from Super I/O config space (8 I/O ports) Datasheet: Publicly available at the ITE website http://www.ite.com.tw/ diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface index 764cdc5480e..a0d0ab24288 100644 --- a/Documentation/hwmon/sysfs-interface +++ b/Documentation/hwmon/sysfs-interface @@ -179,11 +179,12 @@ temp[1-*]_auto_point[1-*]_temp_hyst **************** temp[1-3]_type Sensor type selection. - Integers 1, 2, 3 or thermistor Beta value (3435) + Integers 1 to 4 or thermistor Beta value (typically 3435) Read/Write. 1: PII/Celeron Diode 2: 3904 transistor 3: thermal diode + 4: thermistor (default/unknown Beta) Not all types are supported by all chips temp[1-4]_max Temperature max value. @@ -261,6 +262,21 @@ alarms Alarm bitmask. of individual bits. Bits are defined in kernel/include/sensors.h. +alarms_in Alarm bitmask relative to in (voltage) channels + Read only + A '1' bit means an alarm, LSB corresponds to in0 and so on + Prefered to 'alarms' for newer chips + +alarms_fan Alarm bitmask relative to fan channels + Read only + A '1' bit means an alarm, LSB corresponds to fan1 and so on + Prefered to 'alarms' for newer chips + +alarms_temp Alarm bitmask relative to temp (temperature) channels + Read only + A '1' bit means an alarm, LSB corresponds to temp1 and so on + Prefered to 'alarms' for newer chips + beep_enable Beep/interrupt enable 0 to disable. 1 to enable. diff --git a/Documentation/i2c/busses/i2c-sis69x b/Documentation/i2c/busses/i2c-sis96x index b88953dfd58..00a009b977e 100644 --- a/Documentation/i2c/busses/i2c-sis69x +++ b/Documentation/i2c/busses/i2c-sis96x @@ -7,7 +7,7 @@ Supported adapters: Any combination of these host bridges: 645, 645DX (aka 646), 648, 650, 651, 655, 735, 745, 746 and these south bridges: - 961, 962, 963(L) + 961, 962, 963(L) Author: Mark M. Hoffman <mhoffman@lightlink.com> @@ -29,7 +29,7 @@ The command "lspci" as root should produce something like these lines: or perhaps this... -00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645 +00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645 00:02.0 ISA bridge: Silicon Integrated Systems [SiS]: Unknown device 0961 00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016 diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 2b7cf19a06a..26364d06ae9 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -427,6 +427,23 @@ icmp_ignore_bogus_error_responses - BOOLEAN will avoid log file clutter. Default: FALSE +icmp_errors_use_inbound_ifaddr - BOOLEAN + + If zero, icmp error messages are sent with the primary address of + the exiting interface. + + If non-zero, the message will be sent with the primary address of + the interface that received the packet that caused the icmp error. + This is the behaviour network many administrators will expect from + a router. And it can make debugging complicated network layouts + much easier. + + Note that if no primary address exists for the interface selected, + then the primary address of the first non-loopback interface that + has one will be used regarldess of this setting. + + Default: 0 + igmp_max_memberships - INTEGER Change the maximum number of multicast groups we can subscribe to. Default: 20 diff --git a/Documentation/parport-lowlevel.txt b/Documentation/parport-lowlevel.txt index 1d40008a192..8f2302415ef 100644 --- a/Documentation/parport-lowlevel.txt +++ b/Documentation/parport-lowlevel.txt @@ -1068,7 +1068,7 @@ SYNOPSIS struct parport_operations { ... - void (*write_status) (struct parport *port, unsigned char s); + void (*write_control) (struct parport *port, unsigned char s); ... }; @@ -1097,9 +1097,9 @@ SYNOPSIS struct parport_operations { ... - void (*frob_control) (struct parport *port, - unsigned char mask, - unsigned char val); + unsigned char (*frob_control) (struct parport *port, + unsigned char mask, + unsigned char val); ... }; diff --git a/Documentation/pci-error-recovery.txt b/Documentation/pci-error-recovery.txt index d089967e494..634d3e5b575 100644 --- a/Documentation/pci-error-recovery.txt +++ b/Documentation/pci-error-recovery.txt @@ -1,246 +1,396 @@ PCI Error Recovery ------------------ - May 31, 2005 - - Current document maintainer: - Linas Vepstas <linas@austin.ibm.com> - - -Some PCI bus controllers are able to detect certain "hard" PCI errors -on the bus, such as parity errors on the data and address busses, as -well as SERR and PERR errors. These chipsets are then able to disable -I/O to/from the affected device, so that, for example, a bad DMA -address doesn't end up corrupting system memory. These same chipsets -are also able to reset the affected PCI device, and return it to -working condition. This document describes a generic API form -performing error recovery. - -The core idea is that after a PCI error has been detected, there must -be a way for the kernel to coordinate with all affected device drivers -so that the pci card can be made operational again, possibly after -performing a full electrical #RST of the PCI card. The API below -provides a generic API for device drivers to be notified of PCI -errors, and to be notified of, and respond to, a reset sequence. - -Preliminary sketch of API, cut-n-pasted-n-modified email from -Ben Herrenschmidt, circa 5 april 2005 + February 2, 2006 + + Current document maintainer: + Linas Vepstas <linas@austin.ibm.com> + + +Many PCI bus controllers are able to detect a variety of hardware +PCI errors on the bus, such as parity errors on the data and address +busses, as well as SERR and PERR errors. Some of the more advanced +chipsets are able to deal with these errors; these include PCI-E chipsets, +and the PCI-host bridges found on IBM Power4 and Power5-based pSeries +boxes. A typical action taken is to disconnect the affected device, +halting all I/O to it. The goal of a disconnection is to avoid system +corruption; for example, to halt system memory corruption due to DMA's +to "wild" addresses. Typically, a reconnection mechanism is also +offered, so that the affected PCI device(s) are reset and put back +into working condition. The reset phase requires coordination +between the affected device drivers and the PCI controller chip. +This document describes a generic API for notifying device drivers +of a bus disconnection, and then performing error recovery. +This API is currently implemented in the 2.6.16 and later kernels. + +Reporting and recovery is performed in several steps. First, when +a PCI hardware error has resulted in a bus disconnect, that event +is reported as soon as possible to all affected device drivers, +including multiple instances of a device driver on multi-function +cards. This allows device drivers to avoid deadlocking in spinloops, +waiting for some i/o-space register to change, when it never will. +It also gives the drivers a chance to defer incoming I/O as +needed. + +Next, recovery is performed in several stages. Most of the complexity +is forced by the need to handle multi-function devices, that is, +devices that have multiple device drivers associated with them. +In the first stage, each driver is allowed to indicate what type +of reset it desires, the choices being a simple re-enabling of I/O +or requesting a hard reset (a full electrical #RST of the PCI card). +If any driver requests a full reset, that is what will be done. + +After a full reset and/or a re-enabling of I/O, all drivers are +again notified, so that they may then perform any device setup/config +that may be required. After these have all completed, a final +"resume normal operations" event is sent out. + +The biggest reason for choosing a kernel-based implementation rather +than a user-space implementation was the need to deal with bus +disconnects of PCI devices attached to storage media, and, in particular, +disconnects from devices holding the root file system. If the root +file system is disconnected, a user-space mechanism would have to go +through a large number of contortions to complete recovery. Almost all +of the current Linux file systems are not tolerant of disconnection +from/reconnection to their underlying block device. By contrast, +bus errors are easy to manage in the device driver. Indeed, most +device drivers already handle very similar recovery procedures; +for example, the SCSI-generic layer already provides significant +mechanisms for dealing with SCSI bus errors and SCSI bus resets. + + +Detailed Design +--------------- +Design and implementation details below, based on a chain of +public email discussions with Ben Herrenschmidt, circa 5 April 2005. The error recovery API support is exposed to the driver in the form of a structure of function pointers pointed to by a new field in struct -pci_driver. The absence of this pointer in pci_driver denotes an -"non-aware" driver, behaviour on these is platform dependant. -Platforms like ppc64 can try to simulate pci hotplug remove/add. - -The definition of "pci_error_token" is not covered here. It is based on -Seto's work on the synchronous error detection. We still need to define -functions for extracting infos out of an opaque error token. This is -separate from this API. +pci_driver. A driver that fails to provide the structure is "non-aware", +and the actual recovery steps taken are platform dependent. The +arch/powerpc implementation will simulate a PCI hotplug remove/add. This structure has the form: - struct pci_error_handlers { - int (*error_detected)(struct pci_dev *dev, pci_error_token error); + int (*error_detected)(struct pci_dev *dev, enum pci_channel_state); int (*mmio_enabled)(struct pci_dev *dev); - int (*resume)(struct pci_dev *dev); int (*link_reset)(struct pci_dev *dev); int (*slot_reset)(struct pci_dev *dev); + void (*resume)(struct pci_dev *dev); }; -A driver doesn't have to implement all of these callbacks. The -only mandatory one is error_detected(). If a callback is not -implemented, the corresponding feature is considered unsupported. -For example, if mmio_enabled() and resume() aren't there, then the -driver is assumed as not doing any direct recovery and requires +The possible channel states are: +enum pci_channel_state { + pci_channel_io_normal, /* I/O channel is in normal state */ + pci_channel_io_frozen, /* I/O to channel is blocked */ + pci_channel_io_perm_failure, /* PCI card is dead */ +}; + +Possible return values are: +enum pci_ers_result { + PCI_ERS_RESULT_NONE, /* no result/none/not supported in device driver */ + PCI_ERS_RESULT_CAN_RECOVER, /* Device driver can recover without slot reset */ + PCI_ERS_RESULT_NEED_RESET, /* Device driver wants slot to be reset. */ + PCI_ERS_RESULT_DISCONNECT, /* Device has completely failed, is unrecoverable */ + PCI_ERS_RESULT_RECOVERED, /* Device driver is fully recovered and operational */ +}; + +A driver does not have to implement all of these callbacks; however, +if it implements any, it must implement error_detected(). If a callback +is not implemented, the corresponding feature is considered unsupported. +For example, if mmio_enabled() and resume() aren't there, then it +is assumed that the driver is not doing any direct recovery and requires a reset. If link_reset() is not implemented, the card is assumed as -not caring about link resets, in which case, if recover is supported, -the core can try recover (but not slot_reset() unless it really did -reset the slot). If slot_reset() is not supported, link_reset() can -be called instead on a slot reset. - -At first, the call will always be : - - 1) error_detected() - - Error detected. This is sent once after an error has been detected. At -this point, the device might not be accessible anymore depending on the -platform (the slot will be isolated on ppc64). The driver may already -have "noticed" the error because of a failing IO, but this is the proper -"synchronisation point", that is, it gives a chance to the driver to -cleanup, waiting for pending stuff (timers, whatever, etc...) to -complete; it can take semaphores, schedule, etc... everything but touch -the device. Within this function and after it returns, the driver +not care about link resets. Typically a driver will want to know about +a slot_reset(). + +The actual steps taken by a platform to recover from a PCI error +event will be platform-dependent, but will follow the general +sequence described below. + +STEP 0: Error Event +------------------- +PCI bus error is detect by the PCI hardware. On powerpc, the slot +is isolated, in that all I/O is blocked: all reads return 0xffffffff, +all writes are ignored. + + +STEP 1: Notification +-------------------- +Platform calls the error_detected() callback on every instance of +every driver affected by the error. + +At this point, the device might not be accessible anymore, depending on +the platform (the slot will be isolated on powerpc). The driver may +already have "noticed" the error because of a failing I/O, but this +is the proper "synchronization point", that is, it gives the driver +a chance to cleanup, waiting for pending stuff (timers, whatever, etc...) +to complete; it can take semaphores, schedule, etc... everything but +touch the device. Within this function and after it returns, the driver shouldn't do any new IOs. Called in task context. This is sort of a "quiesce" point. See note about interrupts at the end of this doc. - Result codes: - - PCIERR_RESULT_CAN_RECOVER: - Driever returns this if it thinks it might be able to recover +All drivers participating in this system must implement this call. +The driver must return one of the following result codes: + - PCI_ERS_RESULT_CAN_RECOVER: + Driver returns this if it thinks it might be able to recover the HW by just banging IOs or if it wants to be given - a chance to extract some diagnostic informations (see - below). - - PCIERR_RESULT_NEED_RESET: - Driver returns this if it thinks it can't recover unless the - slot is reset. - - PCIERR_RESULT_DISCONNECT: - Return this if driver thinks it won't recover at all, - (this will detach the driver ? or just leave it - dangling ? to be decided) - -So at this point, we have called error_detected() for all drivers -on the segment that had the error. On ppc64, the slot is isolated. What -happens now typically depends on the result from the drivers. If all -drivers on the segment/slot return PCIERR_RESULT_CAN_RECOVER, we would -re-enable IOs on the slot (or do nothing special if the platform doesn't -isolate slots) and call 2). If not and we can reset slots, we go to 4), -if neither, we have a dead slot. If it's an hotplug slot, we might -"simulate" reset by triggering HW unplug/replug though. - ->>> Current ppc64 implementation assumes that a device driver will ->>> *not* schedule or semaphore in this routine; the current ppc64 + a chance to extract some diagnostic information (see + mmio_enable, below). + - PCI_ERS_RESULT_NEED_RESET: + Driver returns this if it can't recover without a hard + slot reset. + - PCI_ERS_RESULT_DISCONNECT: + Driver returns this if it doesn't want to recover at all. + +The next step taken will depend on the result codes returned by the +drivers. + +If all drivers on the segment/slot return PCI_ERS_RESULT_CAN_RECOVER, +then the platform should re-enable IOs on the slot (or do nothing in +particular, if the platform doesn't isolate slots), and recovery +proceeds to STEP 2 (MMIO Enable). + +If any driver requested a slot reset (by returning PCI_ERS_RESULT_NEED_RESET), +then recovery proceeds to STEP 4 (Slot Reset). + +If the platform is unable to recover the slot, the next step +is STEP 6 (Permanent Failure). + +>>> The current powerpc implementation assumes that a device driver will +>>> *not* schedule or semaphore in this routine; the current powerpc >>> implementation uses one kernel thread to notify all devices; ->>> thus, of one device sleeps/schedules, all devices are affected. +>>> thus, if one device sleeps/schedules, all devices are affected. >>> Doing better requires complex multi-threaded logic in the error >>> recovery implementation (e.g. waiting for all notification threads >>> to "join" before proceeding with recovery.) This seems excessively >>> complex and not worth implementing. ->>> The current ppc64 implementation doesn't much care if the device ->>> attempts i/o at this point, or not. I/O's will fail, returning +>>> The current powerpc implementation doesn't much care if the device +>>> attempts I/O at this point, or not. I/O's will fail, returning >>> a value of 0xff on read, and writes will be dropped. If the device >>> driver attempts more than 10K I/O's to a frozen adapter, it will >>> assume that the device driver has gone into an infinite loop, and ->>> it will panic the the kernel. +>>> it will panic the the kernel. There doesn't seem to be any other +>>> way of stopping a device driver that insists on spinning on I/O. - 2) mmio_enabled() +STEP 2: MMIO Enabled +------------------- +The platform re-enables MMIO to the device (but typically not the +DMA), and then calls the mmio_enabled() callback on all affected +device drivers. - This is the "early recovery" call. IOs are allowed again, but DMA is +This is the "early recovery" call. IOs are allowed again, but DMA is not (hrm... to be discussed, I prefer not), with some restrictions. This is NOT a callback for the driver to start operations again, only to peek/poke at the device, extract diagnostic information, if any, and eventually do things like trigger a device local reset or some such, -but not restart operations. This is sent if all drivers on a segment -agree that they can try to recover and no automatic link reset was -performed by the HW. If the platform can't just re-enable IOs without -a slot reset or a link reset, it doesn't call this callback and goes -directly to 3) or 4). All IOs should be done _synchronously_ from -within this callback, errors triggered by them will be returned via -the normal pci_check_whatever() api, no new error_detected() callback -will be issued due to an error happening here. However, such an error -might cause IOs to be re-blocked for the whole segment, and thus -invalidate the recovery that other devices on the same segment might -have done, forcing the whole segment into one of the next states, -that is link reset or slot reset. - - Result codes: - - PCIERR_RESULT_RECOVERED +but not restart operations. This is callback is made if all drivers on +a segment agree that they can try to recover and if no automatic link reset +was performed by the HW. If the platform can't just re-enable IOs without +a slot reset or a link reset, it wont call this callback, and instead +will have gone directly to STEP 3 (Link Reset) or STEP 4 (Slot Reset) + +>>> The following is proposed; no platform implements this yet: +>>> Proposal: All I/O's should be done _synchronously_ from within +>>> this callback, errors triggered by them will be returned via +>>> the normal pci_check_whatever() API, no new error_detected() +>>> callback will be issued due to an error happening here. However, +>>> such an error might cause IOs to be re-blocked for the whole +>>> segment, and thus invalidate the recovery that other devices +>>> on the same segment might have done, forcing the whole segment +>>> into one of the next states, that is, link reset or slot reset. + +The driver should return one of the following result codes: + - PCI_ERS_RESULT_RECOVERED Driver returns this if it thinks the device is fully - functionnal and thinks it is ready to start + functional and thinks it is ready to start normal driver operations again. There is no guarantee that the driver will actually be allowed to proceed, as another driver on the same segment might have failed and thus triggered a slot reset on platforms that support it. - - PCIERR_RESULT_NEED_RESET + - PCI_ERS_RESULT_NEED_RESET Driver returns this if it thinks the device is not recoverable in it's current state and it needs a slot reset to proceed. - - PCIERR_RESULT_DISCONNECT + - PCI_ERS_RESULT_DISCONNECT Same as above. Total failure, no recovery even after reset driver dead. (To be defined more precisely) ->>> The current ppc64 implementation does not implement this callback. +The next step taken depends on the results returned by the drivers. +If all drivers returned PCI_ERS_RESULT_RECOVERED, then the platform +proceeds to either STEP3 (Link Reset) or to STEP 5 (Resume Operations). + +If any driver returned PCI_ERS_RESULT_NEED_RESET, then the platform +proceeds to STEP 4 (Slot Reset) - 3) link_reset() +>>> The current powerpc implementation does not implement this callback. - This is called after the link has been reset. This is typically -a PCI Express specific state at this point and is done whenever a -non-fatal error has been detected that can be "solved" by resetting -the link. This call informs the driver of the reset and the driver -should check if the device appears to be in working condition. -This function acts a bit like 2) mmio_enabled(), in that the driver -is not supposed to restart normal driver I/O operations right away. -Instead, it should just "probe" the device to check it's recoverability -status. If all is right, then the core will call resume() once all -drivers have ack'd link_reset(). + +STEP 3: Link Reset +------------------ +The platform resets the link, and then calls the link_reset() callback +on all affected device drivers. This is a PCI-Express specific state +and is done whenever a non-fatal error has been detected that can be +"solved" by resetting the link. This call informs the driver of the +reset and the driver should check to see if the device appears to be +in working condition. + +The driver is not supposed to restart normal driver I/O operations +at this point. It should limit itself to "probing" the device to +check it's recoverability status. If all is right, then the platform +will call resume() once all drivers have ack'd link_reset(). Result codes: - (identical to mmio_enabled) + (identical to STEP 3 (MMIO Enabled) + +The platform then proceeds to either STEP 4 (Slot Reset) or STEP 5 +(Resume Operations). + +>>> The current powerpc implementation does not implement this callback. + + +STEP 4: Slot Reset +------------------ +The platform performs a soft or hard reset of the device, and then +calls the slot_reset() callback. + +A soft reset consists of asserting the adapter #RST line and then +restoring the PCI BAR's and PCI configuration header to a state +that is equivalent to what it would be after a fresh system +power-on followed by power-on BIOS/system firmware initialization. +If the platform supports PCI hotplug, then the reset might be +performed by toggling the slot electrical power off/on. ->>> The current ppc64 implementation does not implement this callback. +It is important for the platform to restore the PCI config space +to the "fresh poweron" state, rather than the "last state". After +a slot reset, the device driver will almost always use its standard +device initialization routines, and an unusual config space setup +may result in hung devices, kernel panics, or silent data corruption. - 4) slot_reset() +This call gives drivers the chance to re-initialize the hardware +(re-download firmware, etc.). At this point, the driver may assume +that he card is in a fresh state and is fully functional. In +particular, interrupt generation should work normally. - This is called after the slot has been soft or hard reset by the -platform. A soft reset consists of asserting the adapter #RST line -and then restoring the PCI BARs and PCI configuration header. If the -platform supports PCI hotplug, then it might instead perform a hard -reset by toggling power on the slot off/on. This call gives drivers -the chance to re-initialize the hardware (re-download firmware, etc.), -but drivers shouldn't restart normal I/O processing operations at -this point. (See note about interrupts; interrupts aren't guaranteed -to be delivered until the resume() callback has been called). If all -device drivers report success on this callback, the patform will call -resume() to complete the error handling and let the driver restart -normal I/O processing. +Drivers should not yet restart normal I/O processing operations +at this point. If all device drivers report success on this +callback, the platform will call resume() to complete the sequence, +and let the driver restart normal I/O processing. A driver can still return a critical failure for this function if it can't get the device operational after reset. If the platform -previously tried a soft reset, it migh now try a hard reset (power +previously tried a soft reset, it might now try a hard reset (power cycle) and then call slot_reset() again. It the device still can't be recovered, there is nothing more that can be done; the platform will typically report a "permanent failure" in such a case. The device will be considered "dead" in this case. - Result codes: - - PCIERR_RESULT_DISCONNECT - Same as above. +Drivers for multi-function cards will need to coordinate among +themselves as to which driver instance will perform any "one-shot" +or global device initialization. For example, the Symbios sym53cxx2 +driver performs device init only from PCI function 0: ->>> The current ppc64 implementation does not try a power-cycle reset ->>> if the driver returned PCIERR_RESULT_DISCONNECT. However, it should. ++ if (PCI_FUNC(pdev->devfn) == 0) ++ sym_reset_scsi_bus(np, 0); - 5) resume() - - This is called if all drivers on the segment have returned -PCIERR_RESULT_RECOVERED from one of the 3 prevous callbacks. -That basically tells the driver to restart activity, tht everything -is back and running. No result code is taken into account here. If -a new error happens, it will restart a new error handling process. + Result codes: + - PCI_ERS_RESULT_DISCONNECT + Same as above. -That's it. I think this covers all the possibilities. The way those -callbacks are called is platform policy. A platform with no slot reset -capability for example may want to just "ignore" drivers that can't +Platform proceeds either to STEP 5 (Resume Operations) or STEP 6 (Permanent +Failure). + +>>> The current powerpc implementation does not currently try a +>>> power-cycle reset if the driver returned PCI_ERS_RESULT_DISCONNECT. +>>> However, it probably should. + + +STEP 5: Resume Operations +------------------------- +The platform will call the resume() callback on all affected device +drivers if all drivers on the segment have returned +PCI_ERS_RESULT_RECOVERED from one of the 3 previous callbacks. +The goal of this callback is to tell the driver to restart activity, +that everything is back and running. This callback does not return +a result code. + +At this point, if a new error happens, the platform will restart +a new error recovery sequence. + +STEP 6: Permanent Failure +------------------------- +A "permanent failure" has occurred, and the platform cannot recover +the device. The platform will call error_detected() with a +pci_channel_state value of pci_channel_io_perm_failure. + +The device driver should, at this point, assume the worst. It should +cancel all pending I/O, refuse all new I/O, returning -EIO to +higher layers. The device driver should then clean up all of its +memory and remove itself from kernel operations, much as it would +during system shutdown. + +The platform will typically notify the system operator of the +permanent failure in some way. If the device is hotplug-capable, +the operator will probably want to remove and replace the device. +Note, however, not all failures are truly "permanent". Some are +caused by over-heating, some by a poorly seated card. Many +PCI error events are caused by software bugs, e.g. DMA's to +wild addresses or bogus split transactions due to programming +errors. See the discussion in powerpc/eeh-pci-error-recovery.txt +for additional detail on real-life experience of the causes of +software errors. + + +Conclusion; General Remarks +--------------------------- +The way those callbacks are called is platform policy. A platform with +no slot reset capability may want to just "ignore" drivers that can't recover (disconnect them) and try to let other cards on the same segment recover. Keep in mind that in most real life cases, though, there will be only one driver per segment. -Now, there is a note about interrupts. If you get an interrupt and your +Now, a note about interrupts. If you get an interrupt and your device is dead or has been isolated, there is a problem :) - -After much thinking, I decided to leave that to the platform. That is, -the recovery API only precies that: +The current policy is to turn this into a platform policy. +That is, the recovery API only requires that: - There is no guarantee that interrupt delivery can proceed from any device on the segment starting from the error detection and until the -restart callback is sent, at which point interrupts are expected to be +resume callback is sent, at which point interrupts are expected to be fully operational. - - There is no guarantee that interrupt delivery is stopped, that is, ad -river that gets an interrupts after detecting an error, or that detects -and error within the interrupt handler such that it prevents proper + - There is no guarantee that interrupt delivery is stopped, that is, +a driver that gets an interrupt after detecting an error, or that detects +an error within the interrupt handler such that it prevents proper ack'ing of the interrupt (and thus removal of the source) should just -return IRQ_NOTHANDLED. It's up to the platform to deal with taht -condition, typically by masking the irq source during the duration of +return IRQ_NOTHANDLED. It's up to the platform to deal with that +condition, typically by masking the IRQ source during the duration of the error handling. It is expected that the platform "knows" which interrupts are routed to error-management capable slots and can deal -with temporarily disabling that irq number during error processing (this +with temporarily disabling that IRQ number during error processing (this isn't terribly complex). That means some IRQ latency for other devices sharing the interrupt, but there is simply no other way. High end platforms aren't supposed to share interrupts between many devices anyway :) - -Revised: 31 May 2005 Linas Vepstas <linas@austin.ibm.com> +>>> Implementation details for the powerpc platform are discussed in +>>> the file Documentation/powerpc/eeh-pci-error-recovery.txt + +>>> As of this writing, there are six device drivers with patches +>>> implementing error recovery. Not all of these patches are in +>>> mainline yet. These may be used as "examples": +>>> +>>> drivers/scsi/ipr.c +>>> drivers/scsi/sym53cxx_2 +>>> drivers/next/e100.c +>>> drivers/net/e1000 +>>> drivers/net/ixgb +>>> drivers/net/s2io.c + +The End +------- diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 1284498e847..54e5f9b1536 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -880,6 +880,10 @@ address which can extend beyond that limit. - device_type : Should be "soc" - ranges : Should be defined as specified in 1) to describe the translation of SOC addresses for memory mapped SOC registers. + - bus-frequency: Contains the bus frequency for the SOC node. + Typically, the value of this field is filled in by the boot + loader. + Recommended properties: @@ -919,6 +923,7 @@ SOC. device_type = "soc"; ranges = <00000000 e0000000 00100000> reg = <e0000000 00003000>; + bus-frequency = <0>; } @@ -1170,6 +1175,8 @@ platforms are moved over to use the flattened-device-tree model. mdio@24520 { reg = <24520 20>; + device_type = "mdio"; + compatible = "gianfar"; ethernet-phy@0 { ...... @@ -1317,6 +1324,7 @@ not necessary as they are usually the same as the root node. device_type = "soc"; ranges = <00000000 e0000000 00100000> reg = <e0000000 00003000>; + bus-frequency = <0>; mdio@24520 { reg = <24520 20>; diff --git a/Documentation/spi/butterfly b/Documentation/spi/butterfly index a2e8c8d90e3..9927af7a629 100644 --- a/Documentation/spi/butterfly +++ b/Documentation/spi/butterfly @@ -12,13 +12,20 @@ You can make this adapter from an old printer cable and solder things directly to the Butterfly. Or (if you have the parts and skills) you can come up with something fancier, providing ciruit protection to the Butterfly and the printer port, or with a better power supply than two -signal pins from the printer port. +signal pins from the printer port. Or for that matter, you can use +similar cables to talk to many AVR boards, even a breadboard. + +This is more powerful than "ISP programming" cables since it lets kernel +SPI protocol drivers interact with the AVR, and could even let the AVR +issue interrupts to them. Later, your protocol driver should work +easily with a "real SPI controller", instead of this bitbanger. The first cable connections will hook Linux up to one SPI bus, with the AVR and a DataFlash chip; and to the AVR reset line. This is all you need to reflash the firmware, and the pins are the standard Atmel "ISP" -connector pins (used also on non-Butterfly AVR boards). +connector pins (used also on non-Butterfly AVR boards). On the parport +side this is like "sp12" programming cables. Signal Butterfly Parport (DB-25) ------ --------- --------------- @@ -40,10 +47,14 @@ by clearing PORTB.[0-3]); (b) configure the mtd_dataflash driver; and SELECT = J400.PB0/nSS = pin 17/C3,nSELECT GND = J400.GND = pin 24/GND -The "USI" controller, using J405, can be used for a second SPI bus. That -would let you talk to the AVR over SPI, running firmware that makes it act -as an SPI slave, while letting either Linux or the AVR use the DataFlash. -There are plenty of spare parport pins to wire this one up, such as: +Or you could flash firmware making the AVR into an SPI slave (keeping the +DataFlash in reset) and tweak the spi_butterfly driver to make it bind to +the driver for your custom SPI-based protocol. + +The "USI" controller, using J405, can also be used for a second SPI bus. +That would let you talk to the AVR using custom SPI-with-USI firmware, +while letting either Linux or the AVR use the DataFlash. There are plenty +of spare parport pins to wire this one up, such as: Signal Butterfly Parport (DB-25) ------ --------- --------------- diff --git a/Documentation/unshare.txt b/Documentation/unshare.txt new file mode 100644 index 00000000000..90a5e9e5bef --- /dev/null +++ b/Documentation/unshare.txt @@ -0,0 +1,295 @@ + +unshare system call: +-------------------- +This document describes the new system call, unshare. The document +provides an overview of the feature, why it is needed, how it can +be used, its interface specification, design, implementation and +how it can be tested. + +Change Log: +----------- +version 0.1 Initial document, Janak Desai (janak@us.ibm.com), Jan 11, 2006 + +Contents: +--------- + 1) Overview + 2) Benefits + 3) Cost + 4) Requirements + 5) Functional Specification + 6) High Level Design + 7) Low Level Design + 8) Test Specification + 9) Future Work + +1) Overview +----------- +Most legacy operating system kernels support an abstraction of threads +as multiple execution contexts within a process. These kernels provide +special resources and mechanisms to maintain these "threads". The Linux +kernel, in a clever and simple manner, does not make distinction +between processes and "threads". The kernel allows processes to share +resources and thus they can achieve legacy "threads" behavior without +requiring additional data structures and mechanisms in the kernel. The +power of implementing threads in this manner comes not only from +its simplicity but also from allowing application programmers to work +outside the confinement of all-or-nothing shared resources of legacy +threads. On Linux, at the time of thread creation using the clone system +call, applications can selectively choose which resources to share +between threads. + +unshare system call adds a primitive to the Linux thread model that +allows threads to selectively 'unshare' any resources that were being +shared at the time of their creation. unshare was conceptualized by +Al Viro in the August of 2000, on the Linux-Kernel mailing list, as part +of the discussion on POSIX threads on Linux. unshare augments the +usefulness of Linux threads for applications that would like to control +shared resources without creating a new process. unshare is a natural +addition to the set of available primitives on Linux that implement +the concept of process/thread as a virtual machine. + +2) Benefits +----------- +unshare would be useful to large application frameworks such as PAM +where creating a new process to control sharing/unsharing of process +resources is not possible. Since namespaces are shared by default +when creating a new process using fork or clone, unshare can benefit +even non-threaded applications if they have a need to disassociate +from default shared namespace. The following lists two use-cases +where unshare can be used. + +2.1 Per-security context namespaces +----------------------------------- +unshare can be used to implement polyinstantiated directories using +the kernel's per-process namespace mechanism. Polyinstantiated directories, +such as per-user and/or per-security context instance of /tmp, /var/tmp or +per-security context instance of a user's home directory, isolate user +processes when working with these directories. Using unshare, a PAM +module can easily setup a private namespace for a user at login. +Polyinstantiated directories are required for Common Criteria certification +with Labeled System Protection Profile, however, with the availability +of shared-tree feature in the Linux kernel, even regular Linux systems +can benefit from setting up private namespaces at login and +polyinstantiating /tmp, /var/tmp and other directories deemed +appropriate by system administrators. + +2.2 unsharing of virtual memory and/or open files +------------------------------------------------- +Consider a client/server application where the server is processing +client requests by creating processes that share resources such as +virtual memory and open files. Without unshare, the server has to +decide what needs to be shared at the time of creating the process +which services the request. unshare allows the server an ability to +disassociate parts of the context during the servicing of the +request. For large and complex middleware application frameworks, this +ability to unshare after the process was created can be very +useful. + +3) Cost +------- +In order to not duplicate code and to handle the fact that unshare +works on an active task (as opposed to clone/fork working on a newly +allocated inactive task) unshare had to make minor reorganizational +changes to copy_* functions utilized by clone/fork system call. +There is a cost associated with altering existing, well tested and +stable code to implement a new feature that may not get exercised +extensively in the beginning. However, with proper design and code +review of the changes and creation of an unshare test for the LTP +the benefits of this new feature can exceed its cost. + +4) Requirements +--------------- +unshare reverses sharing that was done using clone(2) system call, +so unshare should have a similar interface as clone(2). That is, +since flags in clone(int flags, void *stack) specifies what should +be shared, similar flags in unshare(int flags) should specify +what should be unshared. Unfortunately, this may appear to invert +the meaning of the flags from the way they are used in clone(2). +However, there was no easy solution that was less confusing and that +allowed incremental context unsharing in future without an ABI change. + +unshare interface should accommodate possible future addition of +new context flags without requiring a rebuild of old applications. +If and when new context flags are added, unshare design should allow +incremental unsharing of those resources on an as needed basis. + +5) Functional Specification +--------------------------- +NAME + unshare - disassociate parts of the process execution context + +SYNOPSIS + #include <sched.h> + + int unshare(int flags); + +DESCRIPTION + unshare allows a process to disassociate parts of its execution + context that are currently being shared with other processes. Part + of execution context, such as the namespace, is shared by default + when a new process is created using fork(2), while other parts, + such as the virtual memory, open file descriptors, etc, may be + shared by explicit request to share them when creating a process + using clone(2). + + The main use of unshare is to allow a process to control its + shared execution context without creating a new process. + + The flags argument specifies one or bitwise-or'ed of several of + the following constants. + + CLONE_FS + If CLONE_FS is set, file system information of the caller + is disassociated from the shared file system information. + + CLONE_FILES + If CLONE_FILES is set, the file descriptor table of the + caller is disassociated from the shared file descriptor + table. + + CLONE_NEWNS + If CLONE_NEWNS is set, the namespace of the caller is + disassociated from the shared namespace. + + CLONE_VM + If CLONE_VM is set, the virtual memory of the caller is + disassociated from the shared virtual memory. + +RETURN VALUE + On success, zero returned. On failure, -1 is returned and errno is + +ERRORS + EPERM CLONE_NEWNS was specified by a non-root process (process + without CAP_SYS_ADMIN). + + ENOMEM Cannot allocate sufficient memory to copy parts of caller's + context that need to be unshared. + + EINVAL Invalid flag was specified as an argument. + +CONFORMING TO + The unshare() call is Linux-specific and should not be used + in programs intended to be portable. + +SEE ALSO + clone(2), fork(2) + +6) High Level Design +-------------------- +Depending on the flags argument, the unshare system call allocates +appropriate process context structures, populates it with values from +the current shared version, associates newly duplicated structures +with the current task structure and releases corresponding shared +versions. Helper functions of clone (copy_*) could not be used +directly by unshare because of the following two reasons. + 1) clone operates on a newly allocated not-yet-active task + structure, where as unshare operates on the current active + task. Therefore unshare has to take appropriate task_lock() + before associating newly duplicated context structures + 2) unshare has to allocate and duplicate all context structures + that are being unshared, before associating them with the + current task and releasing older shared structures. Failure + do so will create race conditions and/or oops when trying + to backout due to an error. Consider the case of unsharing + both virtual memory and namespace. After successfully unsharing + vm, if the system call encounters an error while allocating + new namespace structure, the error return code will have to + reverse the unsharing of vm. As part of the reversal the + system call will have to go back to older, shared, vm + structure, which may not exist anymore. + +Therefore code from copy_* functions that allocated and duplicated +current context structure was moved into new dup_* functions. Now, +copy_* functions call dup_* functions to allocate and duplicate +appropriate context structures and then associate them with the +task structure that is being constructed. unshare system call on +the other hand performs the following: + 1) Check flags to force missing, but implied, flags + 2) For each context structure, call the corresponding unshare + helper function to allocate and duplicate a new context + structure, if the appropriate bit is set in the flags argument. + 3) If there is no error in allocation and duplication and there + are new context structures then lock the current task structure, + associate new context structures with the current task structure, + and release the lock on the current task structure. + 4) Appropriately release older, shared, context structures. + +7) Low Level Design +------------------- +Implementation of unshare can be grouped in the following 4 different +items: + a) Reorganization of existing copy_* functions + b) unshare system call service function + c) unshare helper functions for each different process context + d) Registration of system call number for different architectures + + 7.1) Reorganization of copy_* functions + Each copy function such as copy_mm, copy_namespace, copy_files, + etc, had roughly two components. The first component allocated + and duplicated the appropriate structure and the second component + linked it to the task structure passed in as an argument to the copy + function. The first component was split into its own function. + These dup_* functions allocated and duplicated the appropriate + context structure. The reorganized copy_* functions invoked + their corresponding dup_* functions and then linked the newly + duplicated structures to the task structure with which the + copy function was called. + + 7.2) unshare system call service function + * Check flags + Force implied flags. If CLONE_THREAD is set force CLONE_VM. + If CLONE_VM is set, force CLONE_SIGHAND. If CLONE_SIGHAND is + set and signals are also being shared, force CLONE_THREAD. If + CLONE_NEWNS is set, force CLONE_FS. + * For each context flag, invoke the corresponding unshare_* + helper routine with flags passed into the system call and a + reference to pointer pointing the new unshared structure + * If any new structures are created by unshare_* helper + functions, take the task_lock() on the current task, + modify appropriate context pointers, and release the + task lock. + * For all newly unshared structures, release the corresponding + older, shared, structures. + + 7.3) unshare_* helper functions + For unshare_* helpers corresponding to CLONE_SYSVSEM, CLONE_SIGHAND, + and CLONE_THREAD, return -EINVAL since they are not implemented yet. + For others, check the flag value to see if the unsharing is + required for that structure. If it is, invoke the corresponding + dup_* function to allocate and duplicate the structure and return + a pointer to it. + + 7.4) Appropriately modify architecture specific code to register the + the new system call. + +8) Test Specification +--------------------- +The test for unshare should test the following: + 1) Valid flags: Test to check that clone flags for signal and + signal handlers, for which unsharing is not implemented + yet, return -EINVAL. + 2) Missing/implied flags: Test to make sure that if unsharing + namespace without specifying unsharing of filesystem, correctly + unshares both namespace and filesystem information. + 3) For each of the four (namespace, filesystem, files and vm) + supported unsharing, verify that the system call correctly + unshares the appropriate structure. Verify that unsharing + them individually as well as in combination with each + other works as expected. + 4) Concurrent execution: Use shared memory segments and futex on + an address in the shm segment to synchronize execution of + about 10 threads. Have a couple of threads execute execve, + a couple _exit and the rest unshare with different combination + of flags. Verify that unsharing is performed as expected and + that there are no oops or hangs. + +9) Future Work +-------------- +The current implementation of unshare does not allow unsharing of +signals and signal handlers. Signals are complex to begin with and +to unshare signals and/or signal handlers of a currently running +process is even more complex. If in the future there is a specific +need to allow unsharing of signals and/or signal handlers, it can +be incrementally added to unshare without affecting legacy +applications using unshare. + diff --git a/Documentation/video4linux/CARDLIST.cx88 b/Documentation/video4linux/CARDLIST.cx88 index 56e194f1a0b..8bea3fbd054 100644 --- a/Documentation/video4linux/CARDLIST.cx88 +++ b/Documentation/video4linux/CARDLIST.cx88 @@ -42,4 +42,4 @@ 41 -> Hauppauge WinTV-HVR1100 DVB-T/Hybrid (Low Profile) [0070:9800,0070:9802] 42 -> digitalnow DNTV Live! DVB-T Pro [1822:0025] 43 -> KWorld/VStream XPert DVB-T with cx22702 [17de:08a1] - 44 -> DViCO FusionHDTV DVB-T Dual Digital [18ac:db50] + 44 -> DViCO FusionHDTV DVB-T Dual Digital [18ac:db50,18ac:db54] diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134 index cb3a59bbeb1..8a352597830 100644 --- a/Documentation/video4linux/CARDLIST.saa7134 +++ b/Documentation/video4linux/CARDLIST.saa7134 @@ -1,7 +1,7 @@ 0 -> UNKNOWN/GENERIC 1 -> Proteus Pro [philips reference design] [1131:2001,1131:2001] 2 -> LifeView FlyVIDEO3000 [5168:0138,4e42:0138] - 3 -> LifeView FlyVIDEO2000 [5168:0138] + 3 -> LifeView/Typhoon FlyVIDEO2000 [5168:0138,4e42:0138] 4 -> EMPRESS [1131:6752] 5 -> SKNet Monster TV [1131:4e85] 6 -> Tevion MD 9717 @@ -53,12 +53,12 @@ 52 -> AverMedia AverTV/305 [1461:2108] 53 -> ASUS TV-FM 7135 [1043:4845] 54 -> LifeView FlyTV Platinum FM [5168:0214,1489:0214] - 55 -> LifeView FlyDVB-T DUO [5168:0502,5168:0306] + 55 -> LifeView FlyDVB-T DUO [5168:0306] 56 -> Avermedia AVerTV 307 [1461:a70a] 57 -> Avermedia AVerTV GO 007 FM [1461:f31f] 58 -> ADS Tech Instant TV (saa7135) [1421:0350,1421:0351,1421:0370,1421:1370] 59 -> Kworld/Tevion V-Stream Xpert TV PVR7134 - 60 -> Typhoon DVB-T Duo Digital/Analog Cardbus [4e42:0502] + 60 -> LifeView/Typhoon FlyDVB-T Duo Cardbus [5168:0502,4e42:0502] 61 -> Philips TOUGH DVB-T reference design [1131:2004] 62 -> Compro VideoMate TV Gold+II 63 -> Kworld Xpert TV PVR7134 diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 9c5fc15d03d..153740f460a 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -40,6 +40,18 @@ APICs no_timer_check Don't check the IO-APIC timer. This can work around problems with incorrect timer initialization on some boards. + apicmaintimer Run time keeping from the local APIC timer instead + of using the PIT/HPET interrupt for this. This is useful + when the PIT/HPET interrupts are unreliable. + + noapicmaintimer Don't do time keeping using the APIC timer. + Useful when this option was auto selected, but doesn't work. + + apicpmtimer + Do APIC timer calibration using the pmtimer. Implies + apicmaintimer. Useful when your PIT timer is totally + broken. + Early Console syntax: earlyprintk=vga |