[PATCH AUTOSEL 6.7 17/23] drm/buddy: check range allocation matches alignment

[Sasha Levin]

From: Matthew Auld <matthew.auld at intel.com>

[ Upstream commit 2986314aa811c8a23aeb292edd30315495d54966 ]

Likely not a big deal for real users, but for consistency we should
respect the min_page_size here. Main issue is that bias allocations
turns into normal range allocation if the range and size matches
exactly, and in the next patch we want to add some unit tests for this
part of the api.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam at amd.com>
Cc: Christian König <christian.koenig at amd.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam at amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240219121851.25774-5-matthew.auld@intel.com
Signed-off-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/drm_buddy.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index f3a6ac908f815..5ebdd6f8f36e6 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -771,8 +771,12 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
 		return -EINVAL;
 
 	/* Actual range allocation */
-	if (start + size == end)
+	if (start + size == end) {
+		if (!IS_ALIGNED(start | end, min_block_size))
+			return -EINVAL;
+
 		return __drm_buddy_alloc_range(mm, start, size, NULL, blocks);
+	}
 
 	original_size = size;
 	original_min_size = min_block_size;
-- 
2.43.0