1. 23 9月, 2012 1 次提交
    • S
      Use get_online_cpus to avoid races involving CPU hotplug · 429227bb
      Silas Boyd-Wickizer 提交于
      If arch/x86/kernel/cpuid.c is a module, a CPU might offline or online
      between the for_each_online_cpu() loop and the call to
      register_hotcpu_notifier in cpuid_init or the call to
      unregister_hotcpu_notifier in cpuid_exit.  The potential races can
      lead to leaks/duplicates, attempts to destroy non-existant devices, or
      random pointer dereferences.
      
      For example, in cpuid_exit if:
      
              for_each_online_cpu(cpu)
                      cpuid_device_destroy(cpu);
              class_destroy(cpuid_class);
              __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
              <----- CPU onlines
              unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);
      
      the hotcpu notifier will attempt to create a device for the
      cpuid_class, which the module already destroyed.
      
      This fix surrounds for_each_online_cpu and register_hotcpu_notifier or
      unregister_hotcpu_notifier with get_online_cpus+put_online_cpus.
      
      Tested on a VM.
      Signed-off-by: NSilas Boyd-Wickizer <sbw@mit.edu>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      429227bb
  2. 29 3月, 2012 1 次提交
  3. 27 1月, 2012 2 次提交
    • T
      CPU: Introduce ARCH_HAS_CPU_AUTOPROBE and X86 parts · fad12ac8
      Thomas Renninger 提交于
      This patch is based on Andi Kleen's work:
      Implement autoprobing/loading of modules serving CPU
      specific features (x86cpu autoloading).
      
      And Kay Siever's work to get rid of sysdev cpu structures
      and making use of struct device instead.
      
      Before, the cpuid driver had to be loaded to get the x86cpu
      autoloading feature. With this patch autoloading works through
      the /sys/devices/system/cpu object
      
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: Huang Ying <ying.huang@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Acked-by: NAndi Kleen <ak@linux.intel.com>
      Signed-off-by: NThomas Renninger <trenn@suse.de>
      Acked-by: NH. Peter Anvin <hpa@zytor.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      fad12ac8
    • A
      Add driver auto probing for x86 features v4 · 644e9cbb
      Andi Kleen 提交于
      There's a growing number of drivers that support a specific x86 feature
      or CPU.  Currently loading these drivers currently on a generic
      distribution requires various driver specific hacks and it often
      doesn't work.
      
      This patch adds auto probing for drivers based on the x86 cpuid
      information, in particular based on vendor/family/model number
      and also based on CPUID feature bits.
      
      For example a common issue is not loading the SSE 4.2 accelerated
      CRC module: this can significantly lower the performance of BTRFS
      which relies on fast CRC.
      
      Another issue is loading the right CPUFREQ driver for the current CPU.
      Currently distributions often try all all possible driver until
      one sticks, which is not really a good way to do this.
      
      It works with existing udev without any changes. The code
      exports the x86 information as a generic string in sysfs
      that can be matched by udev's pattern matching.
      
      This scheme does not support numeric ranges, so if you want to
      handle e.g. ranges of model numbers they have to be encoded
      in ASCII or simply all models or families listed. Fixing
      that would require changing udev.
      
      Another issue is that udev will happily load all drivers that match,
      there is currently no nice way to stop a specific driver from
      being loaded if it's not needed (e.g. if you don't need fast CRC)
      But there are not that many cpu specific drivers around and they're
      all not that bloated, so this isn't a particularly serious issue.
      
      Originally this patch added the modalias to the normal cpu
      sysdevs. However sysdevs don't have all the infrastructure
      needed for udev, so it couldn't really autoload drivers.
      This patch instead adds the CPU modaliases to the cpuid devices,
      which are real devices with full support for udev. This implies
      that the cpuid driver has to be loaded to use this.
      
      This patch just adds infrastructure, some driver conversions
      in followups.
      
      Thanks to Kay for helping with some sysfs magic.
      
      v2: Constifcation, some updates
      v4: (trenn@suse.de):
          - Use kzalloc instead of kmalloc to terminate modalias buffer
          - Use uppercase hex values to match correctly against hex values containing
            letters
      
      Cc: Dave Jones <davej@redhat.com>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Cc: Jen Axboe <axboe@kernel.dk>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: Huang Ying <ying.huang@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      Signed-off-by: NThomas Renninger <trenn@suse.de>
      Acked-by: NH. Peter Anvin <hpa@zytor.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      644e9cbb
  4. 04 1月, 2012 1 次提交
  5. 18 11月, 2010 1 次提交
  6. 28 5月, 2010 1 次提交
  7. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  8. 27 1月, 2010 1 次提交
  9. 16 12月, 2009 1 次提交
    • H
      x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers · 0b962d47
      H. Peter Anvin 提交于
      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: NRuss 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: NH. Peter Anvin <hpa@zytor.com>
      LKML-Reference: <tip-*@git.kernel.org>
      0b962d47
  10. 09 10月, 2009 1 次提交
  11. 08 10月, 2009 1 次提交
  12. 20 9月, 2009 1 次提交
  13. 16 6月, 2009 1 次提交
  14. 04 1月, 2009 1 次提交
  15. 03 1月, 2009 1 次提交
  16. 17 10月, 2008 1 次提交
  17. 26 8月, 2008 2 次提交
  18. 11 8月, 2008 1 次提交
  19. 22 7月, 2008 1 次提交
  20. 26 6月, 2008 1 次提交
  21. 19 5月, 2008 1 次提交
  22. 20 4月, 2008 1 次提交
    • R
      PM: Remove destroy_suspended_device() · b844eba2
      Rafael J. Wysocki 提交于
      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: NRafael J. Wysocki <rjw@sisk.pl>
      Acked-by: NPavel Machek <pavel@ucw.cz>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      b844eba2
  23. 04 2月, 2008 2 次提交
  24. 02 2月, 2008 1 次提交
    • S
      x86: fix section mismatch warnings when referencing notifiers · c72258c7
      Sam Ravnborg 提交于
      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: NSam Ravnborg <sam@ravnborg.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      c72258c7
  25. 30 1月, 2008 1 次提交
  26. 25 1月, 2008 1 次提交
    • R
      PM: Acquire device locks on suspend · 775b64d2
      Rafael J. Wysocki 提交于
      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: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      775b64d2
  27. 20 10月, 2007 2 次提交
  28. 18 10月, 2007 2 次提交
  29. 14 10月, 2007 1 次提交
    • D
      Delete filenames in comments. · 835c34a1
      Dave Jones 提交于
      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: NDave Jones <davej@redhat.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      835c34a1
  30. 11 10月, 2007 1 次提交
  31. 10 5月, 2007 1 次提交
    • R
      Add suspend-related notifications for CPU hotplug · 8bb78442
      Rafael J. Wysocki 提交于
      Since nonboot CPUs are now disabled after tasks and devices have been
      frozen and the CPU hotplug infrastructure is used for this purpose, we need
      special CPU hotplug notifications that will help the CPU-hotplug-aware
      subsystems distinguish normal CPU hotplug events from CPU hotplug events
      related to a system-wide suspend or resume operation in progress.  This
      patch introduces such notifications and causes them to be used during
      suspend and resume transitions.  It also changes all of the
      CPU-hotplug-aware subsystems to take these notifications into consideration
      (for now they are handled in the same way as the corresponding "normal"
      ones).
      
      [oleg@tv-sign.ru: cleanups]
      Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      Cc: Gautham R Shenoy <ego@in.ibm.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8bb78442
  32. 13 2月, 2007 2 次提交
  33. 09 12月, 2006 1 次提交
  34. 08 12月, 2006 1 次提交