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authorMatthew Auld <matthew.auld@intel.com>2018-05-11 10:51:40 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2018-05-13 10:29:18 +0100
commitf79401b477bc22914e4c37ea39c611117bd10b19 (patch)
tree87d02c0acaae33cf28065bd63fc9a5d82d48cf4e /drivers/gpu
parente896d29a548d04371ce746f7d02a8488ff93d812 (diff)
downloadop-kernel-dev-f79401b477bc22914e4c37ea39c611117bd10b19.zip
op-kernel-dev-f79401b477bc22914e4c37ea39c611117bd10b19.tar.gz
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')
-rw-r--r--drivers/gpu/drm/i915/i915_gem_gtt.c21
-rw-r--r--drivers/gpu/drm/i915/i915_gem_gtt.h1
-rw-r--r--drivers/gpu/drm/i915/selftests/huge_pages.c3
3 files changed, 25 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index c01d6db..996ab2a 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;
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 1db0ded..aec4f73 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -342,6 +342,7 @@ struct i915_address_space {
void (*clear_pages)(struct i915_vma *vma);
I915_SELFTEST_DECLARE(struct fault_attr fault_attr);
+ I915_SELFTEST_DECLARE(bool scrub_64K);
};
#define i915_is_ggtt(V) (!(V)->file)
diff --git a/drivers/gpu/drm/i915/selftests/huge_pages.c b/drivers/gpu/drm/i915/selftests/huge_pages.c
index d7c8ef8..91c7291 100644
--- a/drivers/gpu/drm/i915/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/selftests/huge_pages.c
@@ -1757,6 +1757,9 @@ int i915_gem_huge_page_live_selftests(struct drm_i915_private *dev_priv)
goto out_unlock;
}
+ if (ctx->ppgtt)
+ ctx->ppgtt->base.scrub_64K = true;
+
err = i915_subtests(tests, ctx);
out_unlock:
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