From: Linus Walleij <linusw@kernel.org>
Date: Tue, 10 Mar 2026 08:53:11 +0000 (+0100)
Subject: dma-buf: heaps: Clear CMA pages with clear_pages()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e669d2f601919aedc6cadca673109684aa499326;p=thirdparty%2Fkernel%2Flinux.git

dma-buf: heaps: Clear CMA pages with clear_pages()

As of commit 62a9f5a85b98
"mm: introduce clear_pages() and clear_user_pages()" we can
clear a range of pages with a potentially assembly-optimized
call.

Instead of using a memset, use this helper to clear the whole
range of pages from the CMA allocation.

Reviewed-by: T.J. Mercier <tjmercier@google.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260310-cma-heap-clear-pages-v2-1-ecbbed3d7e6d@kernel.org
---

diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index bd3370b9a3f6d..f0bacf25ed9dd 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -343,7 +343,7 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
 			nr_clear_pages--;
 		}
 	} else {
-		memset(page_address(cma_pages), 0, size);
+		clear_pages(page_address(cma_pages), pagecount);
 	}
 
 	buffer->pages = kmalloc_objs(*buffer->pages, pagecount);