Commit Graph

28 Commits

Author SHA1 Message Date
Russ Anderson da482474b8 x86, msr/cpuid: Pass the number of minors when unregistering MSR and CPUID drivers.
Pass the number of minors when unregistering MSR and CPUID drivers.

Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Dean Nelson <dnelson@redhat.com>
LKML-Reference: <20100127023722.GA22305@sgi.com>
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-01-26 23:52:38 -08:00
H. Peter Anvin 0b962d473a x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers
register_chrdev() hardcodes registering 256 minors, presumably to
avoid breaking old drivers.  However, we need to register enough
minors so that we have all possible CPUs.

checkpatch warns on this patch, but the patch is correct: NR_CPUS here
is a static *upper bound* on the *maximum CPU index* (not *number of
CPUs!*) and that is what we want.

Reported-and-tested-by: Russ Anderson <rja@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <tip-*@git.kernel.org>
2009-12-15 15:13:07 -08:00
H. Peter Anvin 494c2ebfb2 x86, msr: Remove incorrect, duplicated code in the MSR driver
The MSR driver would compute the values for cpu and c at declaration,
and then again in the body of the function.  This isn't merely
redundant, but unsafe, since cpu might not refer to a valid CPU at
that point.

Remove the unnecessary and dangerous references in the declarations.
This code now matches the equivalent code in the CPUID driver.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-14 10:05:05 -08:00
Linus Torvalds 83be7d764d Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, msr, cpumask: Use struct cpumask rather than the deprecated cpumask_t
  x86, cpuid: Simplify the code in cpuid_open
  x86, cpuid: Remove the bkl from cpuid_open()
  x86, msr: Remove the bkl from msr_open()
  x86: AMD Geode LX optimizations
  x86, msr: Unify rdmsr_on_cpus/wrmsr_on_cpus
2009-12-05 15:32:35 -08:00
Frederic Weisbecker d6c304055b x86, msr: Remove the bkl from msr_open()
Remove the big kernel lock from msr_open() as it doesn't protect
anything there.

The only racy event that can happen here is a concurrent cpu shutdown.

So let's look at what could be racy during/after the above event:

- The cpu_online() check is racy, but the bkl doesn't help about
  that anyway it disables preemption but we may be chcking another
  cpu than the current one.
  Also the cpu can still become offlined between open and read calls.

- The cpu_data(cpu) returns a safe pointer too. It won't be released on
  cpu offlining. But some fields can be changed from
  arch/x86/kernel/smpboot.c:remove_siblinginfo() :

	- phys_proc_id
	- cpu_core_id

  Those are not read from msr_open(). What we are checking is the
  x86_capability that is left untouched on offlining.

So this removal looks safe.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sven-Thorsten Dietrich <sdietrich@suse.de>
LKML-Reference: <1254944602-7382-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-10-07 13:47:19 -07:00
Kay Sievers e454cea20b Driver-Core: extend devnode callbacks to provide permissions
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 12:50:38 -07:00
H. Peter Anvin ff55df53df x86, msr: Export the register-setting MSR functions via /dev/*/msr
Make it possible to access the all-register-setting/getting MSR
functions via the MSR driver.  This is implemented as an ioctl() on
the standard MSR device node.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <petkovbb@gmail.com>
2009-08-31 16:16:04 -07:00
H. Peter Anvin 0cc0213e73 x86, msr: Have the _safe MSR functions return -EIO, not -EFAULT
For some reason, the _safe MSR functions returned -EFAULT, not -EIO.
However, the only user which cares about the return code as anything
other than a boolean is the MSR driver, which wants -EIO.  Change it
to -EIO across the board.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-08-31 15:15:23 -07:00
Kay Sievers 07e9bb8eeb Driver Core: x86: add nodename for cpuid and msr drivers.
This adds support to the x86 cpuid and msr drivers to report the proper
device name to userspace for their devices.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:30:25 -07:00
Jaswinder Singh Rajput 448dd2fa3e x86: msr.c fix style problems
Impact: cleanup

Fix:

 WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>

 total: 0 errors, 1 warnings

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 11:22:50 +01:00
Mike Travis 9628937d5b x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids
Impact: Reduce future system panics due to cpumask operations using NR_CPUS

Insure that code does not look at bits >= nr_cpu_ids as when cpumasks are
allocated based on nr_cpu_ids, these extra bits will not be defined.

Also some other minor updates:

   * change in to use cpu accessor function set_cpu_present() instead of
     directly accessing cpu_present_map w/cpu_clear() [arch/x86/kernel/reboot.c]

   * use cpumask_of() instead of &cpumask_of_cpu() [arch/x86/kernel/reboot.c]

   * optimize some cpu_mask_to_apicid_and functions.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-03 19:00:55 +01:00
Greg Kroah-Hartman a9b12619f7 device create: misc: convert device_create_drvdata to device_create
Now that device_create() has been audited, rename things back to the
original call to be sane.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16 09:24:43 -07:00
H. Peter Anvin 85f1cb6015 x86: msr: correct return value on partial operations
Return the correct return value when the MSR driver partially
completes a request (we should return the number of bytes actually
read or written, instead of the error code.)

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-25 17:46:12 -07:00
H. Peter Anvin c6f31932d0 x86: msr: propagate errors from smp_call_function_single()
Propagate error (-ENXIO) from smp_call_function_single().  These
errors can happen when a CPU is unplugged while the MSR driver is
open.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-25 17:45:48 -07:00
Darrick J. Wong 967060d00d x86, msr: fix NULL pointer deref due to msr_open on nonexistent CPUs
msr_open tests for someone trying to open a device for a nonexistent CPU.
However, the function always returns 0, not ret like it should, hence
userspace can BUG the kernel trivially.  This bug was introduced by the
cdev lock_kernel pushdown patch last May.

The BUG can be reproduced with these commands:

# mknod fubar c 202 8 <-- pick a number less than NR_CPUS that is not
                          the number of an online CPU
# cat fubar

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 13:38:30 +02:00
Greg Kroah-Hartman 3bfd49c8ab device create: x86: convert device_create to device_create_drvdata
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:54:46 -07:00
Jonathan Corbet 5119e92efc x86: cdev lock_kernel() pushdown
Push the cdev lock_kernel() call down into the x86 msr and cpuid drivers.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-05-18 15:43:40 -06:00
Rafael J. Wysocki b844eba292 PM: Remove destroy_suspended_device()
After 2.6.24 there was a plan to make the PM core acquire all device
semaphores during a suspend/hibernation to protect itself from
concurrent operations involving device objects.  That proved to be
too heavy-handed and we found a better way to achieve the goal, but
before it happened, we had introduced the functions
device_pm_schedule_removal() and destroy_suspended_device() to allow
drivers to "safely" destroy a suspended device and we had adapted some
drivers to use them.  Now that these functions are no longer necessary,
it seems reasonable to remove them and modify their users to use the
normal device unregistration instead.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-19 19:10:28 -07:00
Paolo Ciarrocchi 94a9fa4142 x86: coding style fixes to arch/x86/kernel/msr.c
Before:
   total: 2 errors, 0 warnings, 231 lines checked
After:
   total: 0 errors, 0 warnings, 231 lines checked

No code changed:

arch/x86/kernel/msr.o:

   text	   data	    bss	    dec	    hex	filename
   1199	     12	      4	   1215	    4bf	msr.o.before
   1199	     12	      4	   1215	    4bf	msr.o.after

md5:
   604be0d07d829bc52a9346babd084bdc  msr.o.before.asm
   604be0d07d829bc52a9346babd084bdc  msr.o.after.asm

Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 17:40:50 +02:00
H. Peter Anvin 2b06ac8671 x86: cpuid, msr: use inode mutex instead of big kernel lock
Instead of grabbing the BKL on seek, use the inode mutex in the style
of generic_file_llseek().

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04 16:47:59 +01:00
Sam Ravnborg c72258c7c9 x86: fix section mismatch warnings when referencing notifiers
Fix the following warnings:
WARNING: arch/x86/kernel/built-in.o(.exit.text+0xf8): Section mismatch in reference from the function msr_exit() to the variable .cpuinit.data:msr_class_cpu_notifier
WARNING: arch/x86/kernel/built-in.o(.exit.text+0x158): Section mismatch in reference from the function cpuid_exit() to the variable .cpuinit.data:cpuid_class_cpu_notifier
WARNING: arch/x86/kernel/built-in.o(.exit.text+0x171): Section mismatch in reference from the function microcode_exit() to the variable .cpuinit.data:mc_cpu_notifier

In all three cases there were a function annotated __exit
that referenced a variable annotated __cpuinitdata.

The fix was to replace the annotation of the notifier
with __refdata to tell modpost that the reference to
a _cpuinit function in the notifier are OK.
The unregister call that references the notifier
variable will simple delete the function pointer
so there is no problem ignoring the reference.

Note: This looks like another case where __cpuinit
has been used as replacement for proper use
of CONFIG_HOTPLUG_CPU to decide what code are used for
HOTPLUG_CPU.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-01 17:49:42 +01:00
Rafael J. Wysocki 775b64d2b6 PM: Acquire device locks on suspend
This patch reorganizes the way suspend and resume notifications are
sent to drivers.  The major changes are that now the PM core acquires
every device semaphore before calling the methods, and calls to
device_add() during suspends will fail, while calls to device_del()
during suspends will block.

It also provides a way to safely remove a suspended device with the
help of the PM core, by using the device_pm_schedule_removal() callback
introduced specifically for this purpose, and updates two drivers (msr
and cpuid) that need to use it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:04 -08:00
Mike Travis 92cb7612ae x86: convert cpuinfo_x86 array to a per_cpu array
cpu_data is currently an array defined using NR_CPUS.  This means that
we overallocate since we will rarely really use maximum configured cpus.
When NR_CPU count is raised to 4096 the size of cpu_data becomes
3,145,728 bytes.

These changes were adopted from the sparc64 (and ia64) code.  An
additional field was added to cpuinfo_x86 to be a non-ambiguous cpu
index.  This corresponds to the index into a cpumask_t as well as the
per_cpu index.  It's used in various places like show_cpuinfo().

cpu_data is defined to be the boot_cpu_data structure for the NON-SMP
case.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-19 20:35:04 +02:00
Satyam Sharma 38048983e1 x86 msr driver: Misc cpuinit annotations
msr_class_cpu_callback() can be marked __cpuinit, being the notifier callback
for a __cpuinitdata notifier_block.  So can be marked msr_device_create() too,
called only from the newly-__cpuinit msr_class_cpu_callback() or from
__init-marked msr_init().

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:28 -07:00
Akinobu Mita 881a841f4a cpu hotplug: msr: fix cpu hotplug error handling
Do msr_device_create() in CPU_UP_PREPARE instead of CPU_ONLINE.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Andi Kleen <ak@suse.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:21 -07:00
Satyam Sharma 761c4bf821 i386: Misc cpuinit annotations
msr_class_cpu_callback() can be marked __cpuinit, being the notifier
callback for a __cpuinitdata notifier_block. So can be marked
msr_device_create() too, called only from the newly-__cpuinit
msr_class_cpu_callback() or from __init-marked msr_init().

[ tglx: arch/x86 adaptation ]

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 20:16:00 +02:00
Dave Jones 835c34a168 Delete filenames in comments.
Since the x86 merge, lots of files that referenced their own filenames
are no longer correct.  Rather than keep them up to date, just delete
them, as they add no real value.

Additionally:
- fix up comment formatting in scx200_32.c
- Remove a credit from myself in setup_64.c from a time when we had no SCM
- remove longwinded history from tsc_32.c which can be figured out from
  git.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-13 10:01:23 -07:00
Thomas Gleixner 9a163ed8e0 i386: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:17:01 +02:00