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net: page_pool: don't use page->private to store dma_addr_t

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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: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ilias Apalodimas 2019-02-13 02:55:45 +01:00 committed by David S. Miller
parent c25fff7171
commit 1567b85eb8
1 changed files with 9 additions and 4 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

13
net/core/page_pool.c
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@ -136,7 +136,9 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
if (!(pool->p.flags & PP_FLAG_DMA_MAP)) if (!(pool->p.flags & PP_FLAG_DMA_MAP))
goto skip_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. * This mapping is kept for lifetime of page, until leaving pool.
*/ */
dma = dma_map_page(pool->p.dev, page, 0, 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); put_page(page);
return NULL; return NULL;
} }
set_page_private(page, dma); /* page->private = dma; */ page->dma_addr = dma;
skip_dma_map: skip_dma_map:
/* When page just alloc'ed is should/must have refcnt 1. */ /* 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, static void __page_pool_clean_page(struct page_pool *pool,
struct page *page) struct page *page)
{ {
dma_addr_t dma;
if (!(pool->p.flags & PP_FLAG_DMA_MAP)) if (!(pool->p.flags & PP_FLAG_DMA_MAP))
return; return;
dma = page->dma_addr;
/* DMA unmap */ /* 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); 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 */ /* Return a page to the page allocator, cleaning up our state */