[Intel-gfx] [PATCH] drm/i915/selftest: fix 64K alignment in igt_write_huge

[Matthew Auld]

When using softpin it's not enough to just pad the vma size, we also
need to ensure the vma offset is at the start of the pt boundary, if we
plan to utilize 64K pages.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/selftests/huge_pages.c | 28 +++++++++++++--------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/selftests/huge_pages.c b/drivers/gpu/drm/i915/selftests/huge_pages.c
index 256001b00e32..765e69471958 100644
--- a/drivers/gpu/drm/i915/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/selftests/huge_pages.c
@@ -1114,8 +1114,8 @@ static int igt_write_huge(struct i915_gem_context *ctx,
 	struct intel_engine_cs *engine;
 	I915_RND_STATE(prng);
 	IGT_TIMEOUT(end_time);
-	unsigned int max_page_size;
 	unsigned int id;
+	u64 alignment;
 	u64 max;
 	u64 num;
 	u64 size;
@@ -1126,16 +1126,19 @@ static int igt_write_huge(struct i915_gem_context *ctx,
 	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
 
 	size = obj->base.size;
-	if (obj->mm.page_sizes.sg & I915_GTT_PAGE_SIZE_64K)
+	alignment = rounddown_pow_of_two(obj->mm.page_sizes.sg);
+	if (obj->mm.page_sizes.sg & I915_GTT_PAGE_SIZE_64K) {
 		size = round_up(size, I915_GTT_PAGE_SIZE_2M);
+		alignment = max(alignment, I915_GTT_PAGE_SIZE_2M);
+	}
 
-	max_page_size = rounddown_pow_of_two(obj->mm.page_sizes.sg);
-	max = div_u64((vm->total - size), max_page_size);
+	max = div_u64((vm->total - size), alignment);
 
 	n = 0;
 	for_each_engine(engine, i915, id) {
 		if (!intel_engine_can_store_dword(engine)) {
-			pr_info("store-dword-imm not supported on engine=%u\n", id);
+			pr_info("store-dword-imm not supported on engine=%u\n",
+				id);
 			continue;
 		}
 		engines[n++] = engine;
@@ -1160,24 +1163,27 @@ static int igt_write_huge(struct i915_gem_context *ctx,
 	 */
 	i = 0;
 	for_each_prime_number_from(num, 0, max) {
-		u64 offset_low = num * max_page_size;
-		u64 offset_high = (max - num) * max_page_size;
+		u64 offset_low = num * alignment;
+		u64 offset_high = (max - num) * alignment;
 		u32 dword = offset_in_page(num) / 4;
 
 		engine = engines[order[i] % n];
 		i = (i + 1) % (n * I915_NUM_ENGINES);
 
-		err = __igt_write_huge(ctx, engine, obj, size, offset_low, dword, num + 1);
+		err = __igt_write_huge(ctx, engine, obj, size, offset_low,
+				       dword, num + 1);
 		if (err)
 			break;
 
-		err = __igt_write_huge(ctx, engine, obj, size, offset_high, dword, num + 1);
+		err = __igt_write_huge(ctx, engine, obj, size, offset_high,
+				       dword, num + 1);
 		if (err)
 			break;
 
 		if (igt_timeout(end_time,
-				"%s timed out on engine=%u, offset_low=%llx offset_high=%llx, max_page_size=%x\n",
-				__func__, engine->id, offset_low, offset_high, max_page_size))
+				"%s timed out on engine=%u, offset_low=%llx offset_high=%llx, max_page_size=%lx\n",
+				__func__, engine->id, offset_low, offset_high,
+				rounddown_pow_of_two(obj->mm.page_sizes.sg)))
 			break;
 	}
 
-- 
2.17.2