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Get rid of asmlinkage and remove some old cruft from asm/linkage.h.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Implement get_wchan - the algorithm is similar to x86. It starts with the
stack pointer of the process in question and looks above that for addresses
that are kernel text. The second one which isn't in the scheduler is the one
that's returned. The first one is ignored because that will be UML's own
context switching routine.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch removes some code which ran at every boot, but does not seem to do
anything anymore. Please test. It works for me but mistakes can happen.
Signed-off-by: Karol Swietlicki <magotari@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is very old code, it hasn't changed since 2001 and it is not used
anywhere. Noticed by Clemens Koller.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add some new card definitions and fix a typo (from Eugen Paiuc).
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make it possible to unregister a led classdev object in a safe way during a
suspend/resume cycle.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make it possible to unregister a Hardware Random Number Generator
device object in a safe way during a suspend/resume cycle.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Michael Buesch <mb@bu3sch.de>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make it possible to unregister a misc device object in a safe way during a
suspend/resume cycle.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Replace latency.c use with pm_qos_params use.
Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The following patch is a generalization of the latency.c implementation done
by Arjan last year. It provides infrastructure for more than one parameter,
and exposes a user mode interface for processes to register pm_qos
expectations of processes.
This interface provides a kernel and user mode interface for registering
performance expectations by drivers, subsystems and user space applications on
one of the parameters.
Currently we have {cpu_dma_latency, network_latency, network_throughput} as
the initial set of pm_qos parameters.
The infrastructure exposes multiple misc device nodes one per implemented
parameter. The set of parameters implement is defined by pm_qos_power_init()
and pm_qos_params.h. This is done because having the available parameters
being runtime configurable or changeable from a driver was seen as too easy to
abuse.
For each parameter a list of performance requirements is maintained along with
an aggregated target value. The aggregated target value is updated with
changes to the requirement list or elements of the list. Typically the
aggregated target value is simply the max or min of the requirement values
held in the parameter list elements.
>From kernel mode the use of this interface is simple:
pm_qos_add_requirement(param_id, name, target_value):
Will insert a named element in the list for that identified PM_QOS
parameter with the target value. Upon change to this list the new target is
recomputed and any registered notifiers are called only if the target value
is now different.
pm_qos_update_requirement(param_id, name, new_target_value):
Will search the list identified by the param_id for the named list element
and then update its target value, calling the notification tree if the
aggregated target is changed. with that name is already registered.
pm_qos_remove_requirement(param_id, name):
Will search the identified list for the named element and remove it, after
removal it will update the aggregate target and call the notification tree
if the target was changed as a result of removing the named requirement.
>From user mode:
Only processes can register a pm_qos requirement. To provide for
automatic cleanup for process the interface requires the process to register
its parameter requirements in the following way:
To register the default pm_qos target for the specific parameter, the
process must open one of /dev/[cpu_dma_latency, network_latency,
network_throughput]
As long as the device node is held open that process has a registered
requirement on the parameter. The name of the requirement is
"process_<PID>" derived from the current->pid from within the open system
call.
To change the requested target value the process needs to write a s32
value to the open device node. This translates to a
pm_qos_update_requirement call.
To remove the user mode request for a target value simply close the device
node.
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix build again]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Adam Belay <abelay@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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kernel_shutdown_prepare() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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mm/vmalloc.c: In function 'unmap_kernel_range':
mm/vmalloc.c:75: warning: unused variable 'start'
Macros are so horrid.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alpha doesn't use socketcall and doesn't provide __NR_socketcall.
Signed-off-by: Samuel Thibault <samuel.thibault@citrix.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Prevents stuff like
drivers/crypto/hifn_795x.c:2443: warning: format '%d' expects type 'int', but argument 4 has type 'long int'
drivers/crypto/hifn_795x.c:2443: warning: format '%d' expects type 'int', but argument 4 has type 'long int'
(at least).
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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remove dead config symbols from m68knommu code
Signed-off-by: Jiri Olsa <olsajiri@gmail.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Remove dead config symbol from FRV code.
Signed-off-by: Jiri Olsa <olsajiri@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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To be consistent with other architectures, these two DMA macros should
be defined in scatterlist.h as opposed to dma-mapping.h
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Smack is the Simplified Mandatory Access Control Kernel.
Smack implements mandatory access control (MAC) using labels
attached to tasks and data containers, including files, SVIPC,
and other tasks. Smack is a kernel based scheme that requires
an absolute minimum of application support and a very small
amount of configuration data.
Smack uses extended attributes and
provides a set of general mount options, borrowing technics used
elsewhere. Smack uses netlabel for CIPSO labeling. Smack provides
a pseudo-filesystem smackfs that is used for manipulation of
system Smack attributes.
The patch, patches for ls and sshd, a README, a startup script,
and x86 binaries for ls and sshd are also available on
http://www.schaufler-ca.com
Development has been done using Fedora Core 7 in a virtual machine
environment and on an old Sony laptop.
Smack provides mandatory access controls based on the label attached
to a task and the label attached to the object it is attempting to
access. Smack labels are deliberately short (1-23 characters) text
strings. Single character labels using special characters are reserved
for system use. The only operation applied to Smack labels is equality
comparison. No wildcards or expressions, regular or otherwise, are
used. Smack labels are composed of printable characters and may not
include "/".
A file always gets the Smack label of the task that created it.
Smack defines and uses these labels:
"*" - pronounced "star"
"_" - pronounced "floor"
"^" - pronounced "hat"
"?" - pronounced "huh"
The access rules enforced by Smack are, in order:
1. Any access requested by a task labeled "*" is denied.
2. A read or execute access requested by a task labeled "^"
is permitted.
3. A read or execute access requested on an object labeled "_"
is permitted.
4. Any access requested on an object labeled "*" is permitted.
5. Any access requested by a task on an object with the same
label is permitted.
6. Any access requested that is explicitly defined in the loaded
rule set is permitted.
7. Any other access is denied.
Rules may be explicitly defined by writing subject,object,access
triples to /smack/load.
Smack rule sets can be easily defined that describe Bell&LaPadula
sensitivity, Biba integrity, and a variety of interesting
configurations. Smack rule sets can be modified on the fly to
accommodate changes in the operating environment or even the time
of day.
Some practical use cases:
Hierarchical levels. The less common of the two usual uses
for MLS systems is to define hierarchical levels, often
unclassified, confidential, secret, and so on. To set up smack
to support this, these rules could be defined:
C Unclass rx
S C rx
S Unclass rx
TS S rx
TS C rx
TS Unclass rx
A TS process can read S, C, and Unclass data, but cannot write it.
An S process can read C and Unclass. Note that specifying that
TS can read S and S can read C does not imply TS can read C, it
has to be explicitly stated.
Non-hierarchical categories. This is the more common of the
usual uses for an MLS system. Since the default rule is that a
subject cannot access an object with a different label no
access rules are required to implement compartmentalization.
A case that the Bell & LaPadula policy does not allow is demonstrated
with this Smack access rule:
A case that Bell&LaPadula does not allow that Smack does:
ESPN ABC r
ABC ESPN r
On my portable video device I have two applications, one that
shows ABC programming and the other ESPN programming. ESPN wants
to show me sport stories that show up as news, and ABC will
only provide minimal information about a sports story if ESPN
is covering it. Each side can look at the other's info, neither
can change the other. Neither can see what FOX is up to, which
is just as well all things considered.
Another case that I especially like:
SatData Guard w
Guard Publish w
A program running with the Guard label opens a UDP socket and
accepts messages sent by a program running with a SatData label.
The Guard program inspects the message to ensure it is wholesome
and if it is sends it to a program running with the Publish label.
This program then puts the information passed in an appropriate
place. Note that the Guard program cannot write to a Publish
file system object because file system semanitic require read as
well as write.
The four cases (categories, levels, mutual read, guardbox) here
are all quite real, and problems I've been asked to solve over
the years. The first two are easy to do with traditonal MLS systems
while the last two you can't without invoking privilege, at least
for a while.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Joshua Brindle <method@manicmethod.com>
Cc: Paul Moore <paul.moore@hp.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: James Morris <jmorris@namei.org>
Cc: "Ahmed S. Darwish" <darwish.07@gmail.com>
Cc: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add a new set of configuration functions to the NetLabel/LSM API so that
LSMs can perform their own configuration of the NetLabel subsystem without
relying on assistance from userspace.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The capability bounding set is a set beyond which capabilities cannot grow.
Currently cap_bset is per-system. It can be manipulated through sysctl,
but only init can add capabilities. Root can remove capabilities. By
default it includes all caps except CAP_SETPCAP.
This patch makes the bounding set per-process when file capabilities are
enabled. It is inherited at fork from parent. Noone can add elements,
CAP_SETPCAP is required to remove them.
One example use of this is to start a safer container. For instance, until
device namespaces or per-container device whitelists are introduced, it is
best to take CAP_MKNOD away from a container.
The bounding set will not affect pP and pE immediately. It will only
affect pP' and pE' after subsequent exec()s. It also does not affect pI,
and exec() does not constrain pI'. So to really start a shell with no way
of regain CAP_MKNOD, you would do
prctl(PR_CAPBSET_DROP, CAP_MKNOD);
cap_t cap = cap_get_proc();
cap_value_t caparray[1];
caparray[0] = CAP_MKNOD;
cap_set_flag(cap, CAP_INHERITABLE, 1, caparray, CAP_DROP);
cap_set_proc(cap);
cap_free(cap);
The following test program will get and set the bounding
set (but not pI). For instance
./bset get
(lists capabilities in bset)
./bset drop cap_net_raw
(starts shell with new bset)
(use capset, setuid binary, or binary with
file capabilities to try to increase caps)
************************************************************
cap_bound.c
************************************************************
#include <sys/prctl.h>
#include <linux/capability.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef PR_CAPBSET_READ
#define PR_CAPBSET_READ 23
#endif
#ifndef PR_CAPBSET_DROP
#define PR_CAPBSET_DROP 24
#endif
int usage(char *me)
{
printf("Usage: %s get\n", me);
printf(" %s drop <capability>\n", me);
return 1;
}
#define numcaps 32
char *captable[numcaps] = {
"cap_chown",
"cap_dac_override",
"cap_dac_read_search",
"cap_fowner",
"cap_fsetid",
"cap_kill",
"cap_setgid",
"cap_setuid",
"cap_setpcap",
"cap_linux_immutable",
"cap_net_bind_service",
"cap_net_broadcast",
"cap_net_admin",
"cap_net_raw",
"cap_ipc_lock",
"cap_ipc_owner",
"cap_sys_module",
"cap_sys_rawio",
"cap_sys_chroot",
"cap_sys_ptrace",
"cap_sys_pacct",
"cap_sys_admin",
"cap_sys_boot",
"cap_sys_nice",
"cap_sys_resource",
"cap_sys_time",
"cap_sys_tty_config",
"cap_mknod",
"cap_lease",
"cap_audit_write",
"cap_audit_control",
"cap_setfcap"
};
int getbcap(void)
{
int comma=0;
unsigned long i;
int ret;
printf("i know of %d capabilities\n", numcaps);
printf("capability bounding set:");
for (i=0; i<numcaps; i++) {
ret = prctl(PR_CAPBSET_READ, i);
if (ret < 0)
perror("prctl");
else if (ret==1)
printf("%s%s", (comma++) ? ", " : " ", captable[i]);
}
printf("\n");
return 0;
}
int capdrop(char *str)
{
unsigned long i;
int found=0;
for (i=0; i<numcaps; i++) {
if (strcmp(captable[i], str) == 0) {
found=1;
break;
}
}
if (!found)
return 1;
if (prctl(PR_CAPBSET_DROP, i)) {
perror("prctl");
return 1;
}
return 0;
}
int main(int argc, char *argv[])
{
if (argc<2)
return usage(argv[0]);
if (strcmp(argv[1], "get")==0)
return getbcap();
if (strcmp(argv[1], "drop")!=0 || argc<3)
return usage(argv[0]);
if (capdrop(argv[2])) {
printf("unknown capability\n");
return 1;
}
return execl("/bin/bash", "/bin/bash", NULL);
}
************************************************************
[serue@us.ibm.com: fix typo]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>a
Signed-off-by: "Serge E. Hallyn" <serue@us.ibm.com>
Tested-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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KaiGai Kohei observed that this line in the linux header is not needed.
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Cc: KaiGai Kohei <kaigai@kaigai.gr.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The patch supports legacy (32-bit) capability userspace, and where possible
translates 32-bit capabilities to/from userspace and the VFS to 64-bit
kernel space capabilities. If a capability set cannot be compressed into
32-bits for consumption by user space, the system call fails, with -ERANGE.
FWIW libcap-2.00 supports this change (and earlier capability formats)
http://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/
[akpm@linux-foundation.org: coding-syle fixes]
[akpm@linux-foundation.org: use get_task_comm()]
[ezk@cs.sunysb.edu: build fix]
[akpm@linux-foundation.org: do not initialise statics to 0 or NULL]
[akpm@linux-foundation.org: unused var]
[serue@us.ibm.com: export __cap_ symbols]
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: James Morris <jmorris@namei.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revert b68680e4731abbd78863063aaa0dca2a6d8cc723 to make way for the next
patch: "Add 64-bit capability support to the kernel".
We want to keep the vfs_cap_data.data[] structure, using two 'data's for
64-bit caps (and later three for 96-bit caps), whereas
b68680e4731abbd78863063aaa0dca2a6d8cc723 had gotten rid of the 'data' struct
made its members inline.
The 64-bit caps patch keeps the stack abuse fix at get_file_caps(), which was
the more important part of that patch.
[akpm@linux-foundation.org: coding-style fixes]
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: James Morris <jmorris@namei.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Andrew Morgan <morgan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch modifies the interface to inode_getsecurity to have the function
return a buffer containing the security blob and its length via parameters
instead of relying on the calling function to give it an appropriately sized
buffer.
Security blobs obtained with this function should be freed using the
release_secctx LSM hook. This alleviates the problem of the caller having to
guess a length and preallocate a buffer for this function allowing it to be
used elsewhere for Labeled NFS.
The patch also removed the unused err parameter. The conversion is similar to
the one performed by Al Viro for the security_getprocattr hook.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
After making dirty a 100M file, the normal behavior is to start the
writeback for all data after 30s delays. But sometimes the following
happens instead:
- after 30s: ~4M
- after 5s: ~4M
- after 5s: all remaining 92M
Some analyze shows that the internal io dispatch queues goes like this:
s_io s_more_io
-------------------------
1) 100M,1K 0
2) 1K 96M
3) 0 96M
1) initial state with a 100M file and a 1K file
2) 4M written, nr_to_write <= 0, so write more
3) 1K written, nr_to_write > 0, no more writes(BUG)
nr_to_write > 0 in (3) fools the upper layer to think that data have all
been written out. The big dirty file is actually still sitting in
s_more_io. We cannot simply splice s_more_io back to s_io as soon as s_io
becomes empty, and let the loop in generic_sync_sb_inodes() continue: this
may starve newly expired inodes in s_dirty. It is also not an option to
draw inodes from both s_more_io and s_dirty, an let the loop go on: this
might lead to live locks, and might also starve other superblocks in sync
time(well kupdate may still starve some superblocks, that's another bug).
We have to return when a full scan of s_io completes. So nr_to_write > 0
does not necessarily mean that "all data are written". This patch
introduces a flag writeback_control.more_io to indicate that more io should
be done. With it the big dirty file no longer has to wait for the next
kupdate invokation 5s later.
In sync_sb_inodes() we only set more_io on super_blocks we actually
visited. This avoids the interaction between two pdflush deamons.
Also in __sync_single_inode() we don't blindly keep requeuing the io if the
filesystem cannot progress. Failing to do so may lead to 100% iowait.
Tested-by: Mike Snitzer <snitzer@gmail.com>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
After running SetPageUptodate, preceeding stores to the page contents to
actually bring it uptodate may not be ordered with the store to set the
page uptodate.
Therefore, another CPU which checks PageUptodate is true, then reads the
page contents can get stale data.
Fix this by having an smp_wmb before SetPageUptodate, and smp_rmb after
PageUptodate.
Many places that test PageUptodate, do so with the page locked, and this
would be enough to ensure memory ordering in those places if
SetPageUptodate were only called while the page is locked. Unfortunately
that is not always the case for some filesystems, but it could be an idea
for the future.
Also bring the handling of anonymous page uptodateness in line with that of
file backed page management, by marking anon pages as uptodate when they
_are_ uptodate, rather than when our implementation requires that they be
marked as such. Doing allows us to get rid of the smp_wmb's in the page
copying functions, which were especially added for anonymous pages for an
analogous memory ordering problem. Both file and anonymous pages are
handled with the same barriers.
FAQ:
Q. Why not do this in flush_dcache_page?
A. Firstly, flush_dcache_page handles only one side (the smb side) of the
ordering protocol; we'd still need smp_rmb somewhere. Secondly, hiding away
memory barriers in a completely unrelated function is nasty; at least in the
PageUptodate macros, they are located together with (half) the operations
involved in the ordering. Thirdly, the smp_wmb is only required when first
bringing the page uptodate, wheras flush_dcache_page should be called each time
it is written to through the kernel mapping. It is logically the wrong place to
put it.
Q. Why does this increase my text size / reduce my performance / etc.
A. Because it is adding the necessary instructions to eliminate the data-race.
Q. Can it be improved?
A. Yes, eg. if you were to create a rule that all SetPageUptodate operations
run under the page lock, we could avoid the smp_rmb places where PageUptodate
is queried under the page lock. Requires audit of all filesystems and at least
some would need reworking. That's great you're interested, I'm eagerly awaiting
your patches.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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Add vm.highmem_is_dirtyable toggle
A 32 bit machine with HIGHMEM64 enabled running DCC has an MMAPed file of
approximately 2Gb size which contains a hash format that is written
randomly by the dbclean process. On 2.6.16 this process took a few
minutes. With lowmem only accounting of dirty ratios, this takes about 12
hours of 100% disk IO, all random writes.
Include a toggle in /proc/sys/vm/highmem_is_dirtyable which can be set to 1 to
add the highmem back to the total available memory count.
[akpm@linux-foundation.org: Fix the CONFIG_DETECT_SOFTLOCKUP=y build]
Signed-off-by: Bron Gondwana <brong@fastmail.fm>
Cc: Ethan Solomita <solo@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We have repeatedly discussed if the cold pages still have a point. There is
one way to join the two lists: Use a single list and put the cold pages at the
end and the hot pages at the beginning. That way a single list can serve for
both types of allocations.
The discussion of the RFC for this and Mel's measurements indicate that
there may not be too much of a point left to having separate lists for
hot and cold pages (see http://marc.info/?t=119492914200001&r=1&w=2).
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Martin Bligh <mbligh@mbligh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
(with Martin Schwidefsky <schwidefsky@de.ibm.com>)
The pgd/pud/pmd/pte page table allocation functions get a mm_struct pointer as
first argument. The free functions do not get the mm_struct argument. This
is 1) asymmetrical and 2) to do mm related page table allocations the mm
argument is needed on the free function as well.
[kamalesh@linux.vnet.ibm.com: i386 fix]
[akpm@linux-foundation.org: coding-syle fixes]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
- Add comments explaing how drain_pages() works.
- Eliminate useless functions
- Rename drain_all_local_pages to drain_all_pages(). It does drain
all pages not only those of the local processor.
- Eliminate useless interrupt off / on sequences. drain_pages()
disables interrupts on its own. The execution thread is
pinned to processor by the caller. So there is no need to
disable interrupts.
- Put drain_all_pages() declaration in gfp.h and remove the
declarations from suspend.h and from mm/memory_hotplug.c
- Make software suspend call drain_all_pages(). The draining
of processor local pages is may not the right approach if
software suspend wants to support SMP. If they call drain_all_pages
then we can make drain_pages() static.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Daniel Walker <dwalker@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This puts all the clear_refs code where it belongs and probably lets things
compile on MMU-less systems as well.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Introduce a general page table walker
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Move is_swap_pte helper function to swapops.h for use by pagemap code
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The following replaces the earlier patches sent. It should address
David Rientjes's comments, and has been compile tested on all the
architectures that it touches, save for parisc.
For the /proc/<pid>/pagemap code[1], we need to able to query how
much virtual address space a particular task has. The trick is
that we do it through /proc and can't use TASK_SIZE since it
references "current" on some arches. The process opening the
/proc file might be a 32-bit process opening a 64-bit process's
pagemap file.
x86_64 already has a TASK_SIZE_OF() macro:
#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_IA32)) ? IA32_PAGE_OFFSET : TASK_SIZE64)
I'd like to have that for other architectures. So, add it
for all the architectures that actually use "current" in
their TASK_SIZE. For the others, just add a quick #define
in sched.h to use plain old TASK_SIZE.
1. http://www.linuxworld.com/news/2007/042407-kernel.html
- MIPS portion from Ralf Baechle <ralf@linux-mips.org>
[akpm@linux-foundation.org: fix mips build]
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
move_to_swap_cache and move_from_swap_cache functions (which swizzle a page
between tmpfs page cache and swap cache, to avoid page copying) are only used
by shmem.c; and our subsequent fix for unionfs needs different treatments in
the two instances of move_from_swap_cache. Move them from swap_state.c into
their callsites shmem_writepage, shmem_unuse_inode and shmem_getpage, making
add_to_swap_cache externally visible.
shmem.c likes to say set_page_dirty where swap_state.c liked to say
SetPageDirty: respect that diversity, which __set_page_dirty_no_writeback
makes moot (and implies we should lose that "shift page from clean_pages to
dirty_pages list" comment: it's on neither).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Building in a filesystem on a loop device on a tmpfs file can hang when
swapping, the loop thread caught in that infamous throttle_vm_writeout.
In theory this is a long standing problem, which I've either never seen in
practice, or long ago suppressed the recollection, after discounting my load
and my tmpfs size as unrealistically high. But now, with the new aops, it has
become easy to hang on one machine.
Loop used to grab_cache_page before the old prepare_write to tmpfs, which
seems to have been enough to free up some memory for any swapin needed; but
the new write_begin lets tmpfs find or allocate the page (much nicer, since
grab_cache_page missed tmpfs pages in swapcache).
When allocating a fresh page, tmpfs respects loop's mapping_gfp_mask, which
has __GFP_IO|__GFP_FS stripped off, and throttle_vm_writeout is designed to
break out when __GFP_IO or GFP_FS is unset; but when tmfps swaps in,
read_swap_cache_async allocates with GFP_HIGHUSER_MOVABLE regardless of the
mapping_gfp_mask - hence the hang.
So, pass gfp_mask down the line from shmem_getpage to shmem_swapin to
swapin_readahead to read_swap_cache_async to add_to_swap_cache.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
swapin_readahead has never sat well in mm/memory.c: move it to mm/swap_state.c
beside its kindred read_swap_cache_async. Why were its args in a different
order? rearrange them. And since it was always followed by a
read_swap_cache_async of the target page, fold that in and return struct
page*. Then CONFIG_SWAP=n no longer needs valid_swaphandles and
read_swap_cache_async stubs.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Both slab defrag and the large blocksize patches need to ability to take
refcounts on compound pages. May be useful in other places as well.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Checking if an address is a vmalloc address is done in a couple of places.
Define a common version in mm.h and replace the other checks.
Again the include structures suck. The definition of VMALLOC_START and
VMALLOC_END is not available in vmalloc.h since highmem.c cannot be included
there.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
pgtable.h does not include highmem.h but uses various constants from
highmem.h. We cannot include highmem.h because highmem.h will in turn include
many other include files that also depend on pgtable.h
So move the definitions from highmem.h into pgtable.h.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Make vmalloc functions work the same way as kfree() and friends that
take a const void * argument.
[akpm@linux-foundation.org: fix consts, coding-style]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We already have page table manipulation for vmalloc in vmalloc.c. Move the
vmalloc_to_page() function there as well.
Move the definitions for vmalloc related functions in mm.h to a newly created
section. A better place would be vmalloc.h but mm.h is basic and may depend
on these functions. An alternative would be to include vmalloc.h in mm.h
(like done for vmstat.h).
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Simplify page cache zeroing of segments of pages through 3 functions
zero_user_segments(page, start1, end1, start2, end2)
Zeros two segments of the page. It takes the position where to
start and end the zeroing which avoids length calculations and
makes code clearer.
zero_user_segment(page, start, end)
Same for a single segment.
zero_user(page, start, length)
Length variant for the case where we know the length.
We remove the zero_user_page macro. Issues:
1. Its a macro. Inline functions are preferable.
2. The KM_USER0 macro is only defined for HIGHMEM.
Having to treat this special case everywhere makes the
code needlessly complex. The parameter for zeroing is always
KM_USER0 except in one single case that we open code.
Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.
Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.
Also extract the flushing of the caches to be outside of the kmap.
[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Teach AVR32 to use the "GPIO Library" when exposing its GPIOs, so that signals
on external chips (like GPIO expanders) can easily be used.
This mostly reorganizes some existing logic, with two minor changes in
behavior:
- The PSR registers are used instead of the previous "gpio_mask" values,
matching AT91 behavior and removing some duplication between that role
and that of "pinmux_mask".
- NR_IRQs grew to acommodate a bank of external GPIOs. Eventually this
number should probably become a board-specific config option.
There's a debugfs dump of status for the built-in GPIOs, showing which pins
have deglitching, pullups, or open drain drive enabled, as well as the ID
string used when requesting each IRQ.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This adds a new-style I2C driver with basic support for the sixteen bit
PCA9539 GPIO expanders. These chips have multiple registers, push-pull output
drivers, and (not supported in this patch) pin change interrupts.
Board-specific code must provide "pca9539_platform_data" with each chip's
"i2c_board_info". That provides the GPIO numbers to be used by that chip, and
callbacks for board-specific setup/teardown logic.
Derived from drivers/i2c/chips/pca9539.c (which has no current known users).
This is faster and simpler; it uses 16-bit register access, and cache the
OUTPUT and DIRECTION registers for fast access
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Basic driver for 8-bit SPI based MCP23S08 GPIO expander, without support for
IRQs or the shared chipselect mechanism.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is a new-style I2C driver for most common 8 and 16 bit I2C based
"quasi-bidirectional" GPIO expanders: pcf8574 or pcf8575, and several
compatible models (mostly faster, supporting I2C at up to 1 MHz).
The driver exposes the GPIO signals using the platform-neutral GPIO
programming interface, so they are easily accessed by other kernel code. The
lack of such a flexible kernel API has been a big factor in the proliferation
of board-specific drivers for these chips... stuff that rarely makes it
upstream since it's so ugly. This driver will let such boards use standard
calls.
Since it's a new-style driver, these devices must be configured as part of
board-specific init. That eliminates the need for error-prone manual
configuration of module parameters, and makes compatibility with legacy
drivers (pcf8574.c, pc8575.c) for these chips easier (there's a clear
either/or disjunction).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This adds gpiolib support for the PXA architecture:
- move all GPIO API functions from generic.c into gpio.c
- convert the gpio_get/set_value macros into inline functions
This makes it easier to hook up GPIOs provided by external chips like
ASICs and CPLDs.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Minor ARM fixup from David Brownell folded into this ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Provide new implementation infrastructure that platforms may choose to use
when implementing the GPIO programming interface. Platforms can update their
GPIO support to use this. In many cases the incremental cost to access a
non-inlined GPIO should be less than a dozen instructions, with the memory
cost being about a page (total) of extra data and code. The upside is:
* Providing two features which were "want to have (but OK to defer)" when
GPIO interfaces were first discussed in November 2006:
- A "struct gpio_chip" to plug in GPIOs that aren't directly supported
by SOC platforms, but come from FPGAs or other multifunction devices
using conventional device registers (like UCB-1x00 or SM501 GPIOs,
and southbridges in PCs with more open specs than usual).
- Full support for message-based GPIO expanders, where registers are
accessed through sleeping I/O calls. Previous support for these
"cansleep" calls was just stubs. (One example: the widely used
pcf8574 I2C chips, with 8 GPIOs each.)
* Including a non-stub implementation of the gpio_{request,free}() calls,
making those calls much more useful. The diagnostic labels are also
recorded given DEBUG_FS, so /sys/kernel/debug/gpio can show a snapshot
of all GPIOs known to this infrastructure.
The driver programming interfaces introduced in 2.6.21 do not change at all;
this infrastructure is entirely below those covers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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