From: Matthew Auld Date: Mon, 19 Feb 2024 12:18:52 +0000 (+0000) Subject: drm/buddy: fix range bias X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f41900e4a6ef019d64a70394b0e0c3bd048d4ec8;p=linux.git drm/buddy: fix range bias There is a corner case here where start/end is after/before the block range we are currently checking. If so we need to be sure that splitting the block will eventually give use the block size we need. To do that we should adjust the block range to account for the start/end, and only continue with the split if the size/alignment will fit the requested size. Not doing so can result in leaving split blocks unmerged when it eventually fails. Fixes: afea229fe102 ("drm: improve drm_buddy_alloc function") Signed-off-by: Matthew Auld Cc: Arunpravin Paneer Selvam Cc: Christian König Cc: # v5.18+ Reviewed-by: Arunpravin Paneer Selvam Link: https://patchwork.freedesktop.org/patch/msgid/20240219121851.25774-4-matthew.auld@intel.com Signed-off-by: Christian König --- diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index c4222b886db7c..f3a6ac908f815 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -332,6 +332,7 @@ alloc_range_bias(struct drm_buddy *mm, u64 start, u64 end, unsigned int order) { + u64 req_size = mm->chunk_size << order; struct drm_buddy_block *block; struct drm_buddy_block *buddy; LIST_HEAD(dfs); @@ -367,6 +368,15 @@ alloc_range_bias(struct drm_buddy *mm, if (drm_buddy_block_is_allocated(block)) continue; + if (block_start < start || block_end > end) { + u64 adjusted_start = max(block_start, start); + u64 adjusted_end = min(block_end, end); + + if (round_down(adjusted_end + 1, req_size) <= + round_up(adjusted_start, req_size)) + continue; + } + if (contains(start, end, block_start, block_end) && order == drm_buddy_block_order(block)) { /*