1. 18 Dec, 2008 1 commit
    • venkatesh.pallipadi@intel.com's avatar
      x86: PAT: store vm_pgoff for all linear_over_vma_region mappings - v3 · 3c8bb73a
      venkatesh.pallipadi@intel.com authored
      Impact: Code transformation, new functions added should have no effect.
      
      Drivers use mmap followed by pgprot_* and remap_pfn_range or vm_insert_pfn,
      in order to export reserved memory to userspace. Currently, such mappings are
      not tracked and hence not kept consistent with other mappings (/dev/mem,
      pci resource, ioremap) for the sme memory, that may exist in the system.
      
      The following patchset adds x86 PAT attribute tracking and untracking for
      pfnmap related APIs.
      
      First three patches in the patchset are changing the generic mm code to fit
      in this tracking. Last four patches are x86 specific to make things work
      with x86 PAT code. The patchset aso introduces pgprot_writecombine interface,
      which gives writecombine mapping when enabled, falling back to
      pgprot_noncached otherwise.
      
      This patch:
      
      While working on x86 PAT, we faced some hurdles with trackking
      remap_pfn_range() regions, as we do not have any information to say
      whether that PFNMAP mapping is linear for the entire vma range or
      it is smaller granularity regions within the vma.
      
      A simple solution to this is to use vm_pgoff as an indicator for
      linear mapping over the vma region. Currently, remap_pfn_range
      only sets vm_pgoff for COW mappings. Below patch changes the
      logic and sets the vm_pgoff irrespective of COW. This will still not
      be enough for the case where pfn is zero (vma region mapped to
      physical address zero). But, for all the other cases, we can look at
      pfnmap VMAs and say whether the mappng is for the entire vma region
      or not.
      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 avatarH. Peter Anvin <hpa@zytor.com>
      3c8bb73a
  2. 17 Dec, 2008 27 commits
  3. 16 Dec, 2008 12 commits