Messages in this thread Patch in this message | | | From | Yunsheng Lin <> | Subject | [PATCH net-next v2 2/2] page_pool: optimize the cpu sync operation when DMA mapping | Date | Fri, 20 Aug 2021 14:56:51 +0800 |
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If the DMA_ATTR_SKIP_CPU_SYNC is not set, cpu syncing is also done in dma_map_page_attrs(), so set the attrs according to pool->p.flags to avoid calling cpu sync function again.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> --- net/core/page_pool.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 1a69784..3df5554 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -191,8 +191,12 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool, static bool page_pool_dma_map(struct page_pool *pool, struct page *page) { + unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; dma_addr_t dma; + if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) + attrs = 0; + /* Setup DMA mapping: use 'struct page' area for storing DMA-addr * since dma_addr_t can be either 32 or 64 bits and does not always fit * into page private data (i.e 32bit cpu with 64bit DMA caps) @@ -200,15 +204,12 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page) */ dma = dma_map_page_attrs(pool->p.dev, page, 0, (PAGE_SIZE << pool->p.order), - pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + pool->p.dma_dir, attrs); if (dma_mapping_error(pool->p.dev, dma)) return false; page_pool_set_dma_addr(page, dma); - if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) - page_pool_dma_sync_for_device(pool, page, pool->p.max_len); - return true; } -- 2.7.4
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