From b174f139bdc8aaaf72f5b67ad1bd512c4868a87e Mon Sep 17 00:00:00 2001 From: Frank van der Linden Date: Thu, 4 Apr 2024 16:25:14 +0000 Subject: [PATCH] mm/cma: drop incorrect alignment check in cma_init_reserved_mem 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@google.com Fixes: de9e14eebf33 ("drivers: dma-contiguous: add initialization from device tree") Signed-off-by: Frank van der Linden Acked-by: David Hildenbrand Cc: Marek Szyprowski Cc: Muchun Song Cc: Roman Gushchin Cc: Signed-off-by: Andrew Morton --- mm/cma.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index 01f5a8f71ddf..3e9724716bad 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -182,10 +182,6 @@ 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;