Commit dfa59717 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Linus Torvalds
Browse files

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@techsingularity.net


Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Reviewed-by: default avatarIlias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: default avatarAlexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f6e70aab

net/core/page_pool.c

+26 −19
Original line number Diff line number Diff line
@@ -180,14 +180,37 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool, 
					 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_pages_slow(struct page_pool *pool, 
	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. */