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page_pool: use DMA_ATTR_SKIP_CPU_SYNC for DMA mappings

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As pointed out by Alexander Duyck, the DMA mapping done in page_pool needs
to use the DMA attribute DMA_ATTR_SKIP_CPU_SYNC.

As the principle behind page_pool keeping the pages mapped is that the
driver takes over the DMA-sync steps.

Reported-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesper Dangaard Brouer 2019-02-13 02:55:50 +01:00 committed by David S. Miller
parent 1567b85eb8
commit 13f16d9d4a
1 changed files with 6 additions and 5 deletions
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11
net/core/page_pool.c
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@ -141,9 +141,9 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
* into page private data (i.e 32bit cpu with 64bit DMA caps)
* This mapping is kept for lifetime of page, until leaving pool.
*/
dma = dma_map_page(pool->p.dev, page, 0,
(PAGE_SIZE << pool->p.order),
pool->p.dma_dir);
dma = dma_map_page_attrs(pool->p.dev, page, 0,
(PAGE_SIZE << pool->p.order),
pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
if (dma_mapping_error(pool->p.dev, dma)) {
put_page(page);
return NULL;
@ -184,8 +184,9 @@ static void __page_pool_clean_page(struct page_pool *pool,
dma = page->dma_addr;
/* DMA unmap */
dma_unmap_page(pool->p.dev, dma,
PAGE_SIZE << pool->p.order, pool->p.dma_dir);
dma_unmap_page_attrs(pool->p.dev, dma,
PAGE_SIZE << pool->p.order, pool->p.dma_dir,
DMA_ATTR_SKIP_CPU_SYNC);
page->dma_addr = 0;
}