This is a note to let you know that I've just added the patch titled
mm/cma: drop incorrect alignment check in cma_init_reserved_mem
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-cma-drop-incorrect-alignment-check-in-cma_init_re.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f3f649041a190cda4c4b0f15f9898ad8f6653c30
Author: Frank van der Linden <fvdl@xxxxxxxxxx>
Date: Thu Apr 4 16:25:14 2024 +0000
mm/cma: drop incorrect alignment check in cma_init_reserved_mem
[ Upstream commit b174f139bdc8aaaf72f5b67ad1bd512c4868a87e ]
cma_init_reserved_mem uses IS_ALIGNED to check if the size represented by
one bit in the cma allocation bitmask is aligned with
CMA_MIN_ALIGNMENT_BYTES (pageblock size).
However, this is too strict, as this will fail if order_per_bit >
pageblock_order, which is a valid configuration.
We could check IS_ALIGNED both ways, but since both numbers are powers of
two, no check is needed at all.
Link: https://lkml.kernel.org/r/20240404162515.527802-1-fvdl@xxxxxxxxxx
Fixes: de9e14eebf33 ("drivers: dma-contiguous: add initialization from device tree")
Signed-off-by: Frank van der Linden <fvdl@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/mm/cma.c b/mm/cma.c
index 5208aee4f45ad..88fbd4f8124d3 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -179,10 +179,6 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
if (!size || !memblock_is_region_reserved(base, size))
return -EINVAL;
- /* alignment should be aligned with order_per_bit */
- if (!IS_ALIGNED(CMA_MIN_ALIGNMENT_PAGES, 1 << order_per_bit))
- return -EINVAL;
-
/* ensure minimal alignment required by mm core */
if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES))
return -EINVAL;
