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authorKevin Hao <haokexin@gmail.com>2021-02-04 13:56:35 +0300
committerJakub Kicinski <kuba@kernel.org>2021-02-06 22:57:28 +0300
commitb358e2122b9d7aa99f681d4edfafd999845d16ff (patch)
tree2bb2a9ee6ed3e4766ba90da3da0b8c521fbfe94d /include
parenta455fcd7c77046d576dcfe41c1361928dd8b5eaf (diff)
downloadlinux-b358e2122b9d7aa99f681d4edfafd999845d16ff.tar.xz
mm: page_frag: Introduce page_frag_alloc_align()
In the current implementation of page_frag_alloc(), it doesn't have any align guarantee for the returned buffer address. But for some hardwares they do require the DMA buffer to be aligned correctly, so we would have to use some workarounds like below if the buffers allocated by the page_frag_alloc() are used by these hardwares for DMA. buf = page_frag_alloc(really_needed_size + align); buf = PTR_ALIGN(buf, align); These codes seems ugly and would waste a lot of memories if the buffers are used in a network driver for the TX/RX. So introduce page_frag_alloc_align() to make sure that an aligned buffer address is returned. Signed-off-by: Kevin Hao <haokexin@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/gfp.h12
1 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 6e479e9c48ce..80544d5c08e7 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -583,8 +583,16 @@ extern void free_pages(unsigned long addr, unsigned int order);
struct page_frag_cache;
extern void __page_frag_cache_drain(struct page *page, unsigned int count);
-extern void *page_frag_alloc(struct page_frag_cache *nc,
- unsigned int fragsz, gfp_t gfp_mask);
+extern void *page_frag_alloc_align(struct page_frag_cache *nc,
+ unsigned int fragsz, gfp_t gfp_mask,
+ unsigned int align_mask);
+
+static inline void *page_frag_alloc(struct page_frag_cache *nc,
+ unsigned int fragsz, gfp_t gfp_mask)
+{
+ return page_frag_alloc_align(nc, fragsz, gfp_mask, ~0u);
+}
+
extern void page_frag_free(void *addr);
#define __free_page(page) __free_pages((page), 0)