From: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Subject: net: page_pool: refactor dma_map into own function page_pool_dma_map In preparation for next patch, move the dma mapping into its own function, as this will make it easier to follow the changes. [ilias.apalodimas: make page_pool_dma_map return boolean] Link: https://lkml.kernel.org/r/20210325114228.27719-9-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@xxxxxxxxxx> Reviewed-by: Alexander Lobakin <alobakin@xxxxx> Cc: Alexander Duyck <alexander.duyck@xxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Chuck Lever <chuck.lever@xxxxxxxxxx> Cc: David Miller <davem@xxxxxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- net/core/page_pool.c | 45 +++++++++++++++++++++++------------------ 1 file changed, 26 insertions(+), 19 deletions(-) --- a/net/core/page_pool.c~net-page_pool-refactor-dma_map-into-own-function-page_pool_dma_map +++ a/net/core/page_pool.c @@ -180,14 +180,37 @@ static void page_pool_dma_sync_for_devic pool->p.dma_dir); } +static bool page_pool_dma_map(struct page_pool *pool, struct page *page) +{ + dma_addr_t dma; + + /* 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) + * This mapping is kept for lifetime of page, until leaving pool. + */ + 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)) + return false; + + page->dma_addr = dma; + + if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) + page_pool_dma_sync_for_device(pool, page, pool->p.max_len); + + return true; +} + /* slow path */ noinline static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, gfp_t _gfp) { + unsigned int pp_flags = pool->p.flags; struct page *page; gfp_t gfp = _gfp; - dma_addr_t dma; /* We could always set __GFP_COMP, and avoid this branch, as * prep_new_page() can handle order-0 with __GFP_COMP. @@ -211,30 +234,14 @@ static struct page *__page_pool_alloc_pa if (!page) return NULL; - if (!(pool->p.flags & PP_FLAG_DMA_MAP)) - goto skip_dma_map; - - /* 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) - * This mapping is kept for lifetime of page, until leaving pool. - */ - 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)) { + if ((pp_flags & PP_FLAG_DMA_MAP) && + unlikely(!page_pool_dma_map(pool, page))) { put_page(page); return NULL; } - page->dma_addr = dma; - if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) - page_pool_dma_sync_for_device(pool, page, pool->p.max_len); - -skip_dma_map: /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; - trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); /* When page just alloc'ed is should/must have refcnt 1. */ _
