1. 27 5月, 2015 3 次提交
    • T
      x86/mm/mtrr: Use symbolic define as a retval for disabled MTRRs · 3d3ca416
      Toshi Kani 提交于
      mtrr_type_lookup() returns verbatim 0xFF when MTRRs are
      disabled. This patch defines MTRR_TYPE_INVALID to clarify the
      meaning of this value, and documents its usage.
      
      Document the return values of the kernel virtual address mapping
      helpers pud_set_huge(), pmd_set_huge, pud_clear_huge() and
      pmd_clear_huge().
      
      There is no functional change in this patch.
      Signed-off-by: NToshi Kani <toshi.kani@hp.com>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Elliott@hp.com
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Luis R. Rodriguez <mcgrof@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: dave.hansen@intel.com
      Cc: linux-mm <linux-mm@kvack.org>
      Cc: pebolle@tiscali.nl
      Link: http://lkml.kernel.org/r/1431714237-880-5-git-send-email-toshi.kani@hp.com
      Link: http://lkml.kernel.org/r/1432628901-18044-5-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3d3ca416
    • T
      x86/mm/mtrr: Fix MTRR state checks in mtrr_type_lookup() · 9b3aca62
      Toshi Kani 提交于
      'mtrr_state.enabled' contains the FE (fixed MTRRs enabled)
      and E (MTRRs enabled) flags in MSR_MTRRdefType.  Intel SDM,
      section 11.11.2.1, defines these flags as follows:
      
       - All MTRRs are disabled when the E flag is clear.
         The FE flag has no affect when the E flag is clear.
       - The default type is enabled when the E flag is set.
       - MTRR variable ranges are enabled when the E flag is set.
       - MTRR fixed ranges are enabled when both E and FE flags
         are set.
      
      MTRR state checks in __mtrr_type_lookup() do not match with SDM.
      
      Hence, this patch makes the following changes:
       - The current code detects MTRRs disabled when both E and
         FE flags are clear in mtrr_state.enabled.  Fix to detect
         MTRRs disabled when the E flag is clear.
       - The current code does not check if the FE bit is set in
         mtrr_state.enabled when looking at the fixed entries.
         Fix to check the FE flag.
       - The current code returns the default type when the E flag
         is clear in mtrr_state.enabled. However, the default type
         is UC when the E flag is clear.  Remove the code as this
         case is handled as MTRR disabled with the 1st change.
      
      In addition, this patch defines the E and FE flags in
      mtrr_state.enabled as follows.
       - FE flag: MTRR_STATE_MTRR_FIXED_ENABLED
       - E  flag: MTRR_STATE_MTRR_ENABLED
      
      print_mtrr_state() and x86_get_mtrr_mem_range() are also updated
      accordingly.
      Signed-off-by: NToshi Kani <toshi.kani@hp.com>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Elliott@hp.com
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Luis R. Rodriguez <mcgrof@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: dave.hansen@intel.com
      Cc: linux-mm <linux-mm@kvack.org>
      Cc: pebolle@tiscali.nl
      Link: http://lkml.kernel.org/r/1431714237-880-4-git-send-email-toshi.kani@hp.com
      Link: http://lkml.kernel.org/r/1432628901-18044-4-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9b3aca62
    • T
      x86/mm/mtrr: Fix MTRR lookup to handle an inclusive entry · 7f0431e3
      Toshi Kani 提交于
      When an MTRR entry is inclusive to a requested range, i.e. the
      start and end of the request are not within the MTRR entry range
      but the range contains the MTRR entry entirely:
      
        range_start ... [mtrr_start ... mtrr_end] ... range_end
      
      __mtrr_type_lookup() ignores such a case because both
      start_state and end_state are set to zero.
      
      This bug can cause the following issues:
      
      1) reserve_memtype() tracks an effective memory type in case
         a request type is WB (ex. /dev/mem blindly uses WB). Missing
         to track with its effective type causes a subsequent request
         to map the same range with the effective type to fail.
      
      2) pud_set_huge() and pmd_set_huge() check if a requested range
         has any overlap with MTRRs. Missing to detect an overlap may
         cause a performance penalty or undefined behavior.
      
      This patch fixes the bug by adding a new flag, 'inclusive',
      to detect the inclusive case.  This case is then handled in
      the same way as end_state:1 since the first region is the same.
      With this fix, __mtrr_type_lookup() handles the inclusive case
      properly.
      Signed-off-by: NToshi Kani <toshi.kani@hp.com>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Elliott@hp.com
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Luis R. Rodriguez <mcgrof@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: dave.hansen@intel.com
      Cc: linux-mm <linux-mm@kvack.org>
      Cc: pebolle@tiscali.nl
      Link: http://lkml.kernel.org/r/1431714237-880-3-git-send-email-toshi.kani@hp.com
      Link: http://lkml.kernel.org/r/1432628901-18044-3-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      7f0431e3
  2. 11 5月, 2015 1 次提交
  3. 04 2月, 2015 1 次提交
  4. 25 1月, 2014 1 次提交
  5. 12 9月, 2013 1 次提交
    • D
      mm: vmstats: track TLB flush stats on UP too · 6df46865
      Dave Hansen 提交于
      The previous patch doing vmstats for TLB flushes ("mm: vmstats: tlb flush
      counters") effectively missed UP since arch/x86/mm/tlb.c is only compiled
      for SMP.
      
      UP systems do not do remote TLB flushes, so compile those counters out on
      UP.
      
      arch/x86/kernel/cpu/mtrr/generic.c calls __flush_tlb() directly.  This is
      probably an optimization since both the mtrr code and __flush_tlb() write
      cr4.  It would probably be safe to make that a flush_tlb_all() (and then
      get these statistics), but the mtrr code is ancient and I'm hesitant to
      touch it other than to just stick in the counters.
      
      [akpm@linux-foundation.org: tweak comments]
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6df46865
  6. 26 6月, 2013 2 次提交
    • H
      x86, asm, cleanup: Replace open-coded control register values with symbolic · a3d7b7dd
      H. Peter Anvin 提交于
      Clean up an unnecessary open-coded control register values.
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      Link: http://lkml.kernel.org/n/tip-um7za1nzf6brb17o0h4om6e3@git.kernel.org
      a3d7b7dd
    • Y
      x86: Fix /proc/mtrr with base/size more than 44bits · d5c78673
      Yinghai Lu 提交于
      On one sytem that mtrr range is more then 44bits, in dmesg we have
      [    0.000000] MTRR default type: write-back
      [    0.000000] MTRR fixed ranges enabled:
      [    0.000000]   00000-9FFFF write-back
      [    0.000000]   A0000-BFFFF uncachable
      [    0.000000]   C0000-DFFFF write-through
      [    0.000000]   E0000-FFFFF write-protect
      [    0.000000] MTRR variable ranges enabled:
      [    0.000000]   0 [000080000000-0000FFFFFFFF] mask 3FFF80000000 uncachable
      [    0.000000]   1 [380000000000-38FFFFFFFFFF] mask 3F0000000000 uncachable
      [    0.000000]   2 [000099000000-000099FFFFFF] mask 3FFFFF000000 write-through
      [    0.000000]   3 [00009A000000-00009AFFFFFF] mask 3FFFFF000000 write-through
      [    0.000000]   4 [381FFA000000-381FFBFFFFFF] mask 3FFFFE000000 write-through
      [    0.000000]   5 [381FFC000000-381FFC0FFFFF] mask 3FFFFFF00000 write-through
      [    0.000000]   6 [0000AD000000-0000ADFFFFFF] mask 3FFFFF000000 write-through
      [    0.000000]   7 [0000BD000000-0000BDFFFFFF] mask 3FFFFF000000 write-through
      [    0.000000]   8 disabled
      [    0.000000]   9 disabled
      
      but /proc/mtrr report wrong:
      reg00: base=0x080000000 ( 2048MB), size= 2048MB, count=1: uncachable
      reg01: base=0x80000000000 (8388608MB), size=1048576MB, count=1: uncachable
      reg02: base=0x099000000 ( 2448MB), size=   16MB, count=1: write-through
      reg03: base=0x09a000000 ( 2464MB), size=   16MB, count=1: write-through
      reg04: base=0x81ffa000000 (8519584MB), size=   32MB, count=1: write-through
      reg05: base=0x81ffc000000 (8519616MB), size=    1MB, count=1: write-through
      reg06: base=0x0ad000000 ( 2768MB), size=   16MB, count=1: write-through
      reg07: base=0x0bd000000 ( 3024MB), size=   16MB, count=1: write-through
      reg08: base=0x09b000000 ( 2480MB), size=   16MB, count=1: write-combining
      
      so bit 44 and bit 45 get cut off.
      
      We have problems in arch/x86/kernel/cpu/mtrr/generic.c::generic_get_mtrr().
      1. for base, we miss cast base_lo to 64bit before shifting.
      Fix that by adding u64 casting.
      
      2. for size, it only can handle 44 bits aka 32bits + page_shift
      Fix that with 64bit mask instead of 32bit mask_lo, then range could be
      more than 44bits.
      At the same time, we need to update size_or_mask for old cpus that does
      support cpuid 0x80000008 to get phys_addr. Need to set high 32bits
      to all 1s, otherwise will not get correct size for them.
      
      Also fix mtrr_add_page: it should check base and (base + size - 1)
      instead of base and size, as base and size could be small but
      base + size could bigger enough to be out of boundary. We can
      use boot_cpu_data.x86_phys_bits directly to avoid size_or_mask.
      
      So When are we going to have size more than 44bits? that is 16TiB.
      
      after patch we have right ouput:
      reg00: base=0x080000000 ( 2048MB), size= 2048MB, count=1: uncachable
      reg01: base=0x380000000000 (58720256MB), size=1048576MB, count=1: uncachable
      reg02: base=0x099000000 ( 2448MB), size=   16MB, count=1: write-through
      reg03: base=0x09a000000 ( 2464MB), size=   16MB, count=1: write-through
      reg04: base=0x381ffa000000 (58851232MB), size=   32MB, count=1: write-through
      reg05: base=0x381ffc000000 (58851264MB), size=    1MB, count=1: write-through
      reg06: base=0x0ad000000 ( 2768MB), size=   16MB, count=1: write-through
      reg07: base=0x0bd000000 ( 3024MB), size=   16MB, count=1: write-through
      reg08: base=0x09b000000 ( 2480MB), size=   16MB, count=1: write-combining
      
      -v2: simply checking in mtrr_add_page according to hpa.
      
      [ hpa: This probably wants to go into -stable only after having sat in
        mainline for a bit.  It is not a regression. ]
      Signed-off-by: NYinghai Lu <yinghai@kernel.org>
      Link: http://lkml.kernel.org/r/1371162815-29931-1-git-send-email-yinghai@kernel.org
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      d5c78673
  7. 21 1月, 2013 1 次提交
  8. 10 7月, 2012 1 次提交
  9. 29 3月, 2012 1 次提交
  10. 05 12月, 2011 2 次提交
  11. 18 3月, 2011 1 次提交
  12. 11 9月, 2010 2 次提交
  13. 21 7月, 2010 1 次提交
  14. 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
  15. 17 2月, 2010 1 次提交
  16. 16 2月, 2010 1 次提交
  17. 02 2月, 2010 1 次提交
    • E
      x86, mtrr: Constify struct mtrr_ops · 3b9cfc0a
      Emese Revfy 提交于
      This is part of the ops structure constification
      effort started by Arjan van de Ven et al.
      
      Benefits of this constification:
      
       * prevents modification of data that is shared
         (referenced) by many other structure instances
         at runtime
      
       * detects/prevents accidental (but not intentional)
         modification attempts on archs that enforce
         read-only kernel data at runtime
      
       * potentially better optimized code as the compiler
         can assume that the const data cannot be changed
      
       * the compiler/linker move const data into .rodata
         and therefore exclude them from false sharing
      Signed-off-by: NEmese Revfy <re.emese@gmail.com>
      LKML-Reference: <4B65D712.3080804@gmail.com>
      Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      3b9cfc0a
  18. 04 7月, 2009 1 次提交
    • J
      x86: Clean up mtrr/generic.c · a1a499a3
      Jaswinder Singh Rajput 提交于
      Fix following trivial style problems:
      
        ERROR: trailing whitespace X 4
        WARNING: Use #include <linux/io.h> instead of <asm/io.h>
        WARNING: braces {} are not necessary for single statement blocks X 3
        ERROR: "foo * bar" should be "foo *bar"
        WARNING: line over 80 characters X 6
        ERROR: "foo * bar" should be "foo *bar"
        ERROR: spaces required around that '=' (ctx:VxO)
        ERROR: space required before that '-' (ctx:OxV)
        WARNING: suspect code indent for conditional statements (8, 12)
        ERROR: spaces required around that '=' (ctx:VxV)
        ERROR: do not initialise statics to 0 or NULL
        ERROR: space prohibited after that open parenthesis '(' X 2
        ERROR: space prohibited before that close parenthesis ')' X 2
        ERROR: trailing statements should be on next line
        ERROR: return is not a function, parentheses are not required
      
      Also use pr_debug and pr_warning where possible.
      
      arch/x86/kernel/cpu/mtrr/generic.o:
      
         text	   data	    bss	    dec	    hex	filename
         5652	     77	   4224	   9953	   26e1	generic.o.before
         5652	     77	   4220	   9949	   26dd	generic.o.after
      
      The md5 changed:
         b34d6c045f06daa4ed092b90cc760e8f  generic.o.before.asm
         a490c6251cfd8442fbffecc0e09a573d  generic.o.after.asm
      
      Because mtrr_state moved from data to bss, changing its
      offsets - and also because __LINE__ numbers changed.
      Suggested-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      LKML-Reference: <20090703164225.GA21447@elte.hu>
      [ Further cleanups to make the code more consistent ]
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a1a499a3
  19. 15 5月, 2009 5 次提交
  20. 11 5月, 2009 1 次提交
    • Y
      x86: mtrr: Fix high_width computation when phys-addr is >= 44bit · 917a0153
      Yinghai Lu 提交于
      found one system where cpu address line is 44bits, mtrr printout
      is not right:
      
       [    0.000000] MTRR variable ranges enabled:
       [    0.000000]   0 base 0   00000000 mask FF0 00000000 write-back
       [    0.000000]   1 base 10  00000000 mask FFF 80000000 write-back
       [    0.000000]   2 base 0   80000000 mask FFF 80000000 uncachable
       [    0.000000]   3 base 0   7F800000 mask FFF FF800000 uncachable
      
      Li Zefan and Frederic pointed out the high_width could be -4 some how.
      
      It turns out when phys_addr is 44bit, size_or_mask will be
      ffffffff,00000000 so ffs(size_or_mask) will be 0.
      
      Try to check low 32 bit, to get correct high_width.
      Signed-off-by: NYinghai Lu <yinghai@kerne.org>
      Also-analyzed-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Also-analyzed-by: NLi Zefan <lizf@cn.fujitsu.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Cc: Zhaolei <zhaolei@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Vegard Nossum <vegard.nossum@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      LKML-Reference: <4A026540.8060504@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      917a0153
  21. 04 4月, 2009 1 次提交
    • I
      x86, mtrr: remove debug message · c5c67c7c
      Ingo Molnar 提交于
      The MTRR code grew a new debug message which triggers commonly:
      
      [   40.142276]   get_mtrr: cpu0 reg00 base=0000000000 size=0000080000 write-back
      [   40.142280]   get_mtrr: cpu0 reg01 base=0000080000 size=0000040000 write-back
      [   40.142284]   get_mtrr: cpu0 reg02 base=0000100000 size=0000040000 write-back
      [   40.142311]   get_mtrr: cpu0 reg00 base=0000000000 size=0000080000 write-back
      [   40.142314]   get_mtrr: cpu0 reg01 base=0000080000 size=0000040000 write-back
      [   40.142317]   get_mtrr: cpu0 reg02 base=0000100000 size=0000040000 write-back
      
      Remove this annoyance.
      Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      c5c67c7c
  22. 14 3月, 2009 2 次提交
  23. 13 3月, 2009 2 次提交
    • A
      x86: mtrr: don't modify RdDram/WrDram bits of fixed MTRRs · 3ff42da5
      Andreas Herrmann 提交于
      Impact: bug fix + BIOS workaround
      
      BIOS is expected to clear the SYSCFG[MtrrFixDramModEn] on AMD CPUs
      after fixed MTRRs are configured.
      
      Some BIOSes do not clear SYSCFG[MtrrFixDramModEn] on BP (and on APs).
      
      This can lead to obfuscation in Linux when this bit is not cleared on
      BP but cleared on APs. A consequence of this is that the saved
      fixed-MTRR state (from BP) differs from the fixed-MTRRs of APs --
      because RdDram/WrDram bits are read as zero when
      SYSCFG[MtrrFixDramModEn] is cleared -- and Linux tries to sync
      fixed-MTRR state from BP to AP. This implies that Linux sets
      SYSCFG[MtrrFixDramEn] and activates those bits.
      
      More important is that (some) systems change these bits in SMM when
      ACPI is enabled. Hence it is racy if Linux modifies RdMem/WrMem bits,
      too.
      
      (1) The patch modifies an old fix from Bernhard Kaindl to get
          suspend/resume working on some Acer Laptops. Bernhard's patch
          tried to sync RdMem/WrMem bits of fixed MTRR registers and that
          helped on those old Laptops. (Don't ask me why -- can't test it
          myself). But this old problem was not the motivation for the
          patch. (See http://lkml.org/lkml/2007/4/3/110)
      
      (2) The more important effect is to fix issues on some more current systems.
      
          On those systems Linux panics or just freezes, see
      
          http://bugzilla.kernel.org/show_bug.cgi?id=11541
          (and also duplicates of this bug:
          http://bugzilla.kernel.org/show_bug.cgi?id=11737
          http://bugzilla.kernel.org/show_bug.cgi?id=11714)
      
          The affected systems boot only using acpi=ht, acpi=off or
          when the kernel is built with CONFIG_MTRR=n.
      
          The acpi options prevent full enablement of ACPI.  Obviously when
          ACPI is enabled the BIOS/SMM modfies RdMem/WrMem bits.  When
          CONFIG_MTRR=y Linux also accesses and modifies those bits when it
          needs to sync fixed-MTRRs across cores (Bernhard's fix, see (1)).
          How do you synchronize that? You can't. As a consequence Linux
          shouldn't touch those bits at all (Rationale are AMD's BKDGs which
          recommend to clear the bit that makes RdMem/WrMem accessible).
          This is the purpose of this patch. And (so far) this suffices to
          fix (1) and (2).
      
      I suggest not to touch RdDram/WrDram bits of fixed-MTRRs and
      SYSCFG[MtrrFixDramEn] and to clear SYSCFG[MtrrFixDramModEn] as
      suggested by AMD K8, and AMD family 10h/11h BKDGs.
      BIOS is expected to do this anyway. This should avoid that
      Linux and SMM tread on each other's toes ...
      Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
      Cc: trenn@suse.de
      Cc: Yinghai Lu <yinghai@kernel.org>
      LKML-Reference: <20090312163937.GH20716@alberich.amd.com>
      Cc: <stable@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3ff42da5
    • Y
      x86: more MTRR debug printouts · 8ad97905
      Yinghai Lu 提交于
      Impact: improve MTRR debugging messages
      
      There's still inefficiencies suspected with the MTRR sanitizing
      code, so make sure we get all the info we need from a dmesg.
      
      - Remove unneeded mtrr_show
      
       (It will only printout one time by first cpu, so it is no big deal.)
      
      - Also print out directly from get_mtrr, because it doesn't update mtrr_state.
      Signed-off-by: NYinghai Lu <yinghai@kernel.org>
      LKML-Reference: <49B9BA5A.40108@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      8ad97905
  24. 21 1月, 2009 1 次提交
  25. 31 12月, 2008 2 次提交
  26. 22 9月, 2008 1 次提交
  27. 22 8月, 2008 2 次提交
    • I
      x86: work around MTRR mask setting, v2 · 9754a5b8
      Ingo Molnar 提交于
      improve the debug printout:
      
      - make it actually display something
      - print it only once
      
      would be nice to have a WARN_ONCE() facility, to feed such things to
      kerneloops.org.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9754a5b8
    • Y
      x86: work around MTRR mask setting · 38cc1c3d
      Yinghai Lu 提交于
      Joshua Hoblitt reported that only 3 GB of his 16 GB of RAM is
      usable. Booting with mtrr_show showed us the BIOS-initialized
      MTRR settings - which are all wrong.
      
      So the root cause is that the BIOS has not set the mask correctly:
      
      >               [    0.429971]  MSR00000200: 00000000d0000000
      >               [    0.433305]  MSR00000201: 0000000ff0000800
      > should be ==> [    0.433305]  MSR00000201: 0000003ff0000800
      >
      >               [    0.436638]  MSR00000202: 00000000e0000000
      >               [    0.439971]  MSR00000203: 0000000fe0000800
      > should be ==> [    0.439971]  MSR00000203: 0000003fe0000800
      >
      >               [    0.443304]  MSR00000204: 0000000000000006
      >               [    0.446637]  MSR00000205: 0000000c00000800
      > should be ==> [    0.446637]  MSR00000205: 0000003c00000800
      >
      >               [    0.449970]  MSR00000206: 0000000400000006
      >               [    0.453303]  MSR00000207: 0000000fe0000800
      > should be ==> [    0.453303]  MSR00000207: 0000003fe0000800
      >
      >               [    0.456636]  MSR00000208: 0000000420000006
      >               [    0.459970]  MSR00000209: 0000000ff0000800
      > should be ==> [    0.459970]  MSR00000209: 0000003ff0000800
      
      So detect this borkage and add the prefix 111.
      Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
      Cc: <stable@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      38cc1c3d