drm/buddy: fix issue that force_merge cannot free all roots

If buddy manager have more than one roots and each root have sub-block
need to be free. When drm_buddy_fini called, the first loop of
force_merge will merge and free all of the sub block of first root,
which offset is 0x0 and size is biggest(more than have of the mm size).
In subsequent force_merge rounds, if we use 0 as start and use remaining
mm size as end, the block of other roots will be skipped in
__force_merge function. It will cause the other roots can not be freed.

Solution: use roots' offset as the start could fix this issue.

Signed-off-by: Lin.Cao <lincao12@amd.com>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241226070116.309290-1-Arunpravin.PaneerSelvam@amd.com

diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 103c185bb1c8a76ac0fc7a45ce2a5f34c683298a..ca42e6081d27c438709c84a0f6d93fd00c4c328e 100644 (file)
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -324,7 +324,7 @@ EXPORT_SYMBOL(drm_buddy_init);
  */
 void drm_buddy_fini(struct drm_buddy *mm)
 {
-       u64 root_size, size;
+       u64 root_size, size, start;
        unsigned int order;
        int i;
 
@@ -332,7 +332,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
 
        for (i = 0; i < mm->n_roots; ++i) {
                order = ilog2(size) - ilog2(mm->chunk_size);
-               __force_merge(mm, 0, size, order);
+               start = drm_buddy_block_offset(mm->roots[i]);
+               __force_merge(mm, start, start + size, order);
 
                WARN_ON(!drm_buddy_block_is_free(mm->roots[i]));
                drm_block_free(mm, mm->roots[i]);