Commit 1567b85e authored by Ilias Apalodimas's avatar Ilias Apalodimas Committed by David S. Miller
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net: page_pool: don't use page->private to store dma_addr_t 



As pointed out by David Miller the current page_pool implementation
stores dma_addr_t in page->private.
This won't work on 32-bit platforms with 64-bit DMA addresses since the
page->private is an unsigned long and the dma_addr_t a u64.

A previous patch is adding dma_addr_t on struct page to accommodate this.
This patch adapts the page_pool related functions to use the newly added
struct for storing and retrieving DMA addresses from network drivers.

Signed-off-by: default avatarIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c25fff71

net/core/page_pool.c

+9 −4
Original line number Diff line number Diff line
@@ -136,7 +136,9 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, 
	if (!(pool->p.flags & PP_FLAG_DMA_MAP))

		goto skip_dma_map;



	/* Setup DMA mapping: use page->private for DMA-addr

	/* 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(pool->p.dev, page, 0,
@@ -146,7 +148,7 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, 
		put_page(page);

		return NULL;

	}

	set_page_private(page, dma); /* page->private = dma; */

	page->dma_addr = dma;



skip_dma_map:

	/* When page just alloc'ed is should/must have refcnt 1. */
@@ -175,13 +177,16 @@ EXPORT_SYMBOL(page_pool_alloc_pages); 
static void __page_pool_clean_page(struct page_pool *pool,

				   struct page *page)

{

	dma_addr_t dma;



	if (!(pool->p.flags & PP_FLAG_DMA_MAP))

		return;



	dma = page->dma_addr;

	/* DMA unmap */

	dma_unmap_page(pool->p.dev, page_private(page),

	dma_unmap_page(pool->p.dev, dma,

		       PAGE_SIZE << pool->p.order, pool->p.dma_dir);

	set_page_private(page, 0);

	page->dma_addr = 0;

}



/* Return a page to the page allocator, cleaning up our state */

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