[Intel-gfx] [PATCH] drm/i915/gtt: Allow mixed pages to setup large PTE

[Chris Wilson]

For example, we may want to split a 2MiB large page into multiple 64KiB
PTEs. To do so, we want to allow a vma that only has the 2MiB flag set
to utilise the 64KiB as required, i.e. we want to include all larger
pages as well.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c         |  4 ++--
 drivers/gpu/drm/i915/selftests/huge_pages.c | 17 +++++++++++------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 19b2d991b5d8..9e1756216ada 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1074,7 +1074,7 @@ static void gen8_ppgtt_insert_huge_entries(struct i915_vma *vma,
 		gen8_pte_t *vaddr;
 		u16 index, max;
 
-		if (vma->page_sizes.sg & I915_GTT_PAGE_SIZE_2M &&
+		if (vma->page_sizes.sg & -I915_GTT_PAGE_SIZE_2M &&
 		    IS_ALIGNED(iter->dma, I915_GTT_PAGE_SIZE_2M) &&
 		    rem >= I915_GTT_PAGE_SIZE_2M && !idx.pte) {
 			index = idx.pde;
@@ -1092,7 +1092,7 @@ static void gen8_ppgtt_insert_huge_entries(struct i915_vma *vma,
 			page_size = I915_GTT_PAGE_SIZE;
 
 			if (!index &&
-			    vma->page_sizes.sg & I915_GTT_PAGE_SIZE_64K &&
+			    vma->page_sizes.sg & -I915_GTT_PAGE_SIZE_64K &&
 			    IS_ALIGNED(iter->dma, I915_GTT_PAGE_SIZE_64K) &&
 			    (IS_ALIGNED(rem, I915_GTT_PAGE_SIZE_64K) ||
 			     rem >= (max - index) * I915_GTT_PAGE_SIZE))
diff --git a/drivers/gpu/drm/i915/selftests/huge_pages.c b/drivers/gpu/drm/i915/selftests/huge_pages.c
index 256001b00e32..2d66f380ad9a 100644
--- a/drivers/gpu/drm/i915/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/selftests/huge_pages.c
@@ -508,6 +508,7 @@ static int igt_mock_ppgtt_misaligned_dma(void *arg)
 			goto out_unpin;
 		}
 
+		GEM_BUG_ON(vma->page_sizes.gtt);
 		err = i915_vma_pin(vma, 0, 0, flags);
 		if (err) {
 			i915_vma_close(vma);
@@ -517,8 +518,9 @@ static int igt_mock_ppgtt_misaligned_dma(void *arg)
 
 		err = igt_check_page_sizes(vma);
 
-		if (vma->page_sizes.gtt != page_size) {
-			pr_err("page_sizes.gtt=%u, expected %u\n",
+		if (!(vma->page_sizes.gtt & -page_size)) {
+			pr_err("%s:%d page_sizes.gtt=%u, expected %u\n",
+			       __func__, __LINE__,
 			       vma->page_sizes.gtt, page_size);
 			err = -EINVAL;
 		}
@@ -542,6 +544,7 @@ static int igt_mock_ppgtt_misaligned_dma(void *arg)
 				goto out_unpin;
 			}
 
+			GEM_BUG_ON(vma->page_sizes.gtt);
 			err = i915_vma_pin(vma, 0, 0, flags | offset);
 			if (err) {
 				i915_vma_close(vma);
@@ -550,8 +553,9 @@ static int igt_mock_ppgtt_misaligned_dma(void *arg)
 
 			err = igt_check_page_sizes(vma);
 
-			if (vma->page_sizes.gtt != I915_GTT_PAGE_SIZE_4K) {
-				pr_err("page_sizes.gtt=%u, expected %llu\n",
+			if (!(vma->page_sizes.gtt & -I915_GTT_PAGE_SIZE_4K)) {
+				pr_err("%s:%d page_sizes.gtt=%u, expected %llu\n",
+						__func__, __LINE__,
 				       vma->page_sizes.gtt, I915_GTT_PAGE_SIZE_4K);
 				err = -EINVAL;
 			}
@@ -1471,7 +1475,7 @@ static int igt_ppgtt_pin_update(void *arg)
 		if (err)
 			goto out_unpin;
 
-		if (vma->page_sizes.gtt != page_size) {
+		if (!(vma->page_sizes.gtt & -page_size)) {
 			dma_addr_t addr = i915_gem_object_get_dma_address(obj, 0);
 
 			/*
@@ -1481,7 +1485,8 @@ static int igt_ppgtt_pin_update(void *arg)
 			 * address.
 			 */
 			if (IS_ALIGNED(addr, page_size)) {
-				pr_err("page_sizes.gtt=%u, expected=%u\n",
+				pr_err("%s:%d page_sizes.gtt=%u, expected=%u\n",
+						__func__, __LINE__,
 				       vma->page_sizes.gtt, page_size);
 				err = -EINVAL;
 			} else {
-- 
2.19.1