1. 14 Jan, 2009 6 commits
  2. 13 Jan, 2009 4 commits
    • venkatesh.pallipadi@intel.com's avatar
      x86 PAT: remove CPA WARN_ON for zero pte · 58dab916
      venkatesh.pallipadi@intel.com authored
      Impact: reduce scope of debug check - avoid warnings
      
      The logic to find whether identity map exists or not using
      high_memory or max_low_pfn_mapped/max_pfn_mapped are not complete
      as the memory withing the range may not be mapped if there is a
      unusable hole in e820.
      
      Specifically, on my test system I started seeing these warnings with
      tools like hwinfo, acpidump trying to map ACPI region.
      
      [   27.400018] ------------[ cut here ]------------
      [   27.400344] WARNING: at /home/venkip/src/linus/linux-2.6/arch/x86/mm/pageattr.c:560 __change_page_attr_set_clr+0xf3/0x8b8()
      [   27.400821] Hardware name: X7DB8
      [   27.401070] CPA: called for zero pte. vaddr = ffff8800cff6a000 cpa->vaddr = ffff8800cff6a000
      [   27.401569] Modules linked in:
      [   27.401882] Pid: 4913, comm: dmidecode Not tainted 2.6.28-05716-gfe0bdec6
      
       #586
      [   27.402141] Call Trace:
      [   27.402488]  [<ffffffff80237c21>] warn_slowpath+0xd3/0x10f
      [   27.402749]  [<ffffffff80274ade>] ? find_get_page+0xb3/0xc9
      [   27.403028]  [<ffffffff80274a2b>] ? find_get_page+0x0/0xc9
      [   27.403333]  [<ffffffff80226425>] __change_page_attr_set_clr+0xf3/0x8b8
      [   27.403628]  [<ffffffff8028ec99>] ? __purge_vmap_area_lazy+0x192/0x1a1
      [   27.403883]  [<ffffffff8028eb52>] ? __purge_vmap_area_lazy+0x4b/0x1a1
      [   27.404172]  [<ffffffff80290268>] ? vm_unmap_aliases+0x1ab/0x1bb
      [   27.404512]  [<ffffffff80290105>] ? vm_unmap_aliases+0x48/0x1bb
      [   27.404766]  [<ffffffff80226d28>] change_page_attr_set_clr+0x13e/0x2e6
      [   27.405026]  [<ffffffff80698fa7>] ? _spin_unlock+0x26/0x2a
      [   27.405292]  [<ffffffff80227e6a>] ? reserve_memtype+0x19b/0x4e3
      [   27.405590]  [<ffffffff80226ffd>] _set_memory_wb+0x22/0x24
      [   27.405844]  [<ffffffff80225d28>] ioremap_change_attr+0x26/0x28
      [   27.406097]  [<ffffffff80228355>] reserve_pfn_range+0x1a3/0x235
      [   27.406427]  [<ffffffff80228430>] track_pfn_vma_new+0x49/0xb3
      [   27.406686]  [<ffffffff80286c46>] remap_pfn_range+0x94/0x32c
      [   27.406940]  [<ffffffff8022878d>] ? phys_mem_access_prot_allowed+0xb5/0x1a8
      [   27.407209]  [<ffffffff803e9bf4>] mmap_mem+0x75/0x9d
      [   27.407523]  [<ffffffff8028b3b4>] mmap_region+0x2cf/0x53e
      [   27.407776]  [<ffffffff8028b8cc>] do_mmap_pgoff+0x2a9/0x30d
      [   27.408034]  [<ffffffff8020f4a4>] sys_mmap+0x92/0xce
      [   27.408339]  [<ffffffff8020b65b>] system_call_fastpath+0x16/0x1b
      [   27.408614] ---[ end trace 4b16ad70c09a602d ]---
      [   27.408871] dmidecode:4913 reserve_pfn_range ioremap_change_attr failed write-back for cff6a000-cff6b000
      
      This is wih track_pfn_vma_new trying to keep identity map in sync.
      The address cff6a000 is the ACPI region according to e820.
      
      [    0.000000] BIOS-provided physical RAM map:
      [    0.000000]  BIOS-e820: 0000000000000000 - 000000000009c000 (usable)
      [    0.000000]  BIOS-e820: 000000000009c000 - 00000000000a0000 (reserved)
      [    0.000000]  BIOS-e820: 00000000000cc000 - 00000000000d0000 (reserved)
      [    0.000000]  BIOS-e820: 00000000000e4000 - 0000000000100000 (reserved)
      [    0.000000]  BIOS-e820: 0000000000100000 - 00000000cff60000 (usable)
      [    0.000000]  BIOS-e820: 00000000cff60000 - 00000000cff69000 (ACPI data)
      [    0.000000]  BIOS-e820: 00000000cff69000 - 00000000cff80000 (ACPI NVS)
      [    0.000000]  BIOS-e820: 00000000cff80000 - 00000000d0000000 (reserved)
      [    0.000000]  BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
      [    0.000000]  BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
      [    0.000000]  BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
      [    0.000000]  BIOS-e820: 00000000ff000000 - 0000000100000000 (reserved)
      [    0.000000]  BIOS-e820: 0000000100000000 - 0000000230000000 (usable)
      
      And is not mapped as per init_memory_mapping.
      
      [    0.000000] init_memory_mapping: 0000000000000000-00000000cff60000
      [    0.000000] init_memory_mapping: 0000000100000000-0000000230000000
      
      We can add logic to check for this. But, there can also be other holes in
      identity map when we have 1GB of aligned reserved space in e820.
      
      This patch handles it by removing the WARN_ON and returning a specific
      error value (EFAULT) to indicate that the address does not have any
      identity mapping.
      
      The code that tries to keep identity map in sync can ignore
      this error, with other callers of cpa still getting error here.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      58dab916
    • venkatesh.pallipadi@intel.com's avatar
      x86 PAT: return compatible mapping to remap_pfn_range callers · cdecff68
      venkatesh.pallipadi@intel.com authored
      Impact: avoid warning message, potentially solve 3D performance regression
      
      Change x86 PAT code to return compatible memtype if the exact memtype that
      was requested in remap_pfn_rage and friends is not available due to some
      conflict.
      
      This is done by returning the compatible type in pgprot parameter of
      track_pfn_vma_new(), and the caller uses that memtype for page table.
      
      Note that track_pfn_vma_copy() which is basically called during fork gets the
      prot from existing page table and should not have any conflict. Hence we use
      strict memtype check there and do not allow compatible memtypes.
      
      This patch fixes the bug reported here:
      
        http://marc.info/?l=linux-kernel&m=123108883716357&w=2
      
      
      
      Specifically the error message:
      
        X:5010 map pfn expected mapping type write-back for d0000000-d0101000,
        got write-combining
      
      Should go away.
      Reported-and-bisected-by: default avatarKevin Winchester <kjwinchester@gmail.com>
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      cdecff68
    • venkatesh.pallipadi@intel.com's avatar
      x86 PAT: change track_pfn_vma_new to take pgprot_t pointer param · e4b866ed
      venkatesh.pallipadi@intel.com authored
      
      
      Impact: cleanup
      
      Change the protection parameter for track_pfn_vma_new() into a pgprot_t pointer.
      Subsequent patch changes the x86 PAT handling to return a compatible
      memtype in pgprot_t, if what was requested cannot be allowed due to conflicts.
      No fuctionality change in this patch.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      e4b866ed
    • venkatesh.pallipadi@intel.com's avatar
      x86 PAT: consolidate old memtype new memtype check into a function · afc7d20c
      venkatesh.pallipadi@intel.com authored
      
      
      Impact: cleanup
      
      Move the new memtype old memtype allowed check to header so that is can be
      shared by other users. Subsequent patch uses this in pat.c in remap_pfn_range()
      code path. No functionality change in this patch.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      afc7d20c
  3. 12 Jan, 2009 23 commits
  4. 11 Jan, 2009 7 commits