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| author | Matthew Auld | 2018-05-11 11:51:40 +0200 |
|---|---|---|
| committer | Chris Wilson | 2018-05-13 11:29:18 +0200 |
| commit | f79401b477bc22914e4c37ea39c611117bd10b19 (patch) | |
| tree | 87d02c0acaae33cf28065bd63fc9a5d82d48cf4e /drivers/gpu/drm/i915/i915_gem_gtt.c | |
| parent | drm/i915/oa: Check that OA is disabled before unpinning (diff) | |
| download | kernel-qcow2-linux-f79401b477bc22914e4c37ea39c611117bd10b19.tar.gz kernel-qcow2-linux-f79401b477bc22914e4c37ea39c611117bd10b19.tar.xz kernel-qcow2-linux-f79401b477bc22914e4c37ea39c611117bd10b19.zip | |
drm/i915/selftests: scrub 64K
We write all 4K page entries, even when using 64K pages. In order to
verify that the HW isn't cheating by using the 4K PTE instead of the 64K
PTE, we want to remove all the surplus entries. If the HW skipped the
64K PTE, it will read/write into the scratch page instead - which we
detect as missing results during selftests.
v2: much improved commentary (Chris)
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Changbin Du <changbin.du@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180511095140.25590-1-matthew.auld@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_gtt.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_gtt.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index c01d6dbe269a..996ab2ad6c45 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1162,6 +1162,27 @@ static void gen8_ppgtt_insert_huge_entries(struct i915_vma *vma, vaddr[idx.pde] |= GEN8_PDE_IPS_64K; kunmap_atomic(vaddr); page_size = I915_GTT_PAGE_SIZE_64K; + + /* + * We write all 4K page entries, even when using 64K + * pages. In order to verify that the HW isn't cheating + * by using the 4K PTE instead of the 64K PTE, we want + * to remove all the surplus entries. If the HW skipped + * the 64K PTE, it will read/write into the scratch page + * instead - which we detect as missing results during + * selftests. + */ + if (I915_SELFTEST_ONLY(vma->vm->scrub_64K)) { + u16 i; + + encode = pte_encode | vma->vm->scratch_page.daddr; + vaddr = kmap_atomic_px(pd->page_table[idx.pde]); + + for (i = 1; i < index; i += 16) + memset64(vaddr + i, encode, 15); + + kunmap_atomic(vaddr); + } } vma->page_sizes.gtt |= page_size; |