Merge tag 'drm-x86-pat-regression-fix' of git://people.freedesktop.org/~airlied/linux

Pull drm x86/pat regression fixes from Dave Airlie:
 "This is a standalone pull request for the fix for a regression
  introduced in -rc1 by a change to vm_insert_mixed to start using the
  PAT range tracking to validate page protections. With this fix in
  place, all the VRAM mappings for GPU drivers ended up at UC instead of
  WC.

  There are probably better ways to fix this long term, but nothing I'd
  considered for -fixes that wouldn't need more settling in time. So
  I've just created a new arch API that the drivers can reserve all
  their VRAM aperture ranges as WC"

* tag 'drm-x86-pat-regression-fix' of git://people.freedesktop.org/~airlied/linux:
  drm/drivers: add support for using the arch wc mapping API.
  x86/io: add interface to reserve io memtype for a resource range. (v1.1)

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index aa074fac0c7f..f3efb1c5dae9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -754,6 +754,10 @@ static const char *amdgpu_vram_names[] = {
 
 int amdgpu_bo_init(struct amdgpu_device *adev)
 {
+	/* reserve PAT memory space to WC for VRAM */
+	arch_io_reserve_memtype_wc(adev->mc.aper_base,
+				   adev->mc.aper_size);
+
 	/* Add an MTRR for the VRAM */
 	adev->mc.vram_mtrr = arch_phys_wc_add(adev->mc.aper_base,
 					      adev->mc.aper_size);
@@ -769,6 +773,7 @@ void amdgpu_bo_fini(struct amdgpu_device *adev)
 {
 	amdgpu_ttm_fini(adev);
 	arch_phys_wc_del(adev->mc.vram_mtrr);
+	arch_io_free_memtype_wc(adev->mc.aper_base, adev->mc.aper_size);
 }
 
 int amdgpu_bo_fbdev_mmap(struct amdgpu_bo *bo,