[Intel-gfx] [PATCH] drm/i915: round_up the size to the alignment value

[Arunpravin]

handle instances when size is not aligned with the min_page_size.
Unigine Heaven has allocation requests for example required pages
are 161 and alignment request is 128. To allocate the left over
33 pages, continues the iteration to find the order value which
is 5 and 0 and when it compares with min_order = 7, triggers the
BUG_ON((order < min_order). To avoid this problem, round_up the
size to the alignment and enable the is_contiguous variable and
the block trimmed to the original size.

Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam at amd.com>
---
 drivers/gpu/drm/i915/i915_ttm_buddy_manager.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
index 129f668f21ff..318aa731de5b 100644
--- a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
+++ b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
@@ -40,6 +40,7 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
 	struct i915_ttm_buddy_resource *bman_res;
 	struct drm_buddy *mm = &bman->mm;
 	unsigned long n_pages, lpfn;
+	bool is_contiguous = 0;
 	u64 min_page_size;
 	u64 size;
 	int err;
@@ -48,6 +49,9 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
 	if (!lpfn)
 		lpfn = man->size;
 
+	if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
+		is_contiguous = 1;
+
 	bman_res = kzalloc(sizeof(*bman_res), GFP_KERNEL);
 	if (!bman_res)
 		return -ENOMEM;
@@ -71,7 +75,12 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
 
 	GEM_BUG_ON(min_page_size < mm->chunk_size);
 
-	if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
+	if (!is_contiguous && !IS_ALIGNED(size, min_page_size)) {
+		size = round_up(size, min_page_size);
+		is_contiguous = 1;
+	}
+
+	if (is_contiguous) {
 		unsigned long pages;
 
 		size = roundup_pow_of_two(size);
@@ -106,7 +115,7 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
 	if (unlikely(err))
 		goto err_free_blocks;
 
-	if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
+	if (is_contiguous) {
 		u64 original_size = (u64)bman_res->base.num_pages << PAGE_SHIFT;
 
 		mutex_lock(&bman->lock);

base-commit: b37605de46fef48555bf0cf463cccf355c51fac0
-- 
2.25.1