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authorBen Hutchings <bhutchings@solarflare.com>2013-01-10 23:51:54 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-28 12:06:01 -0700
commit67d8c1035e0c960a3d41abe532ea868bb3985f22 (patch)
tree9f08673bbb83325b1a7cf771ef20b6906d938cd7
parentbbd3cfb8cbb326f32f1daec0ea6ffbf855a7ecc8 (diff)
sfc: Fix efx_rx_buf_offset() in the presence of swiotlb
[ Upstream commits 06e63c57acbb1df7c35ebe846ae416a8b88dfafa, b590ace09d51cd39744e0f7662c5e4a0d1b5d952 and c73e787a8db9117d59b5180baf83203a42ecadca ] We assume that the mapping between DMA and virtual addresses is done on whole pages, so we can find the page offset of an RX buffer using the lower bits of the DMA address. However, swiotlb maps in units of 2K, breaking this assumption. Add an explicit page_offset field to struct efx_rx_buffer. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> [bwh: Backported to 3.0: adjust context] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/sfc/net_driver.h4
-rw-r--r--drivers/net/sfc/rx.c10
2 files changed, 8 insertions, 6 deletions
diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index 47aff8ec720..2f932c594bf 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -214,6 +214,7 @@ struct efx_tx_queue {
* If both this and page are %NULL, the buffer slot is currently free.
* @page: The associated page buffer, if any.
* If both this and skb are %NULL, the buffer slot is currently free.
+ * @page_offset: Offset within page. Valid iff @flags & %EFX_RX_BUF_PAGE.
* @len: Buffer length, in bytes.
* @is_page: Indicates if @page is valid. If false, @skb is valid.
*/
@@ -223,7 +224,8 @@ struct efx_rx_buffer {
struct sk_buff *skb;
struct page *page;
} u;
- unsigned int len;
+ u16 page_offset;
+ u16 len;
bool is_page;
};
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
index ce6f53fc48a..d429f0aadb0 100644
--- a/drivers/net/sfc/rx.c
+++ b/drivers/net/sfc/rx.c
@@ -94,11 +94,7 @@ static unsigned int rx_refill_limit = 95;
static inline unsigned int efx_rx_buf_offset(struct efx_nic *efx,
struct efx_rx_buffer *buf)
{
- /* Offset is always within one page, so we don't need to consider
- * the page order.
- */
- return (((__force unsigned long) buf->dma_addr & (PAGE_SIZE - 1)) +
- efx->type->rx_buffer_hash_size);
+ return buf->page_offset + efx->type->rx_buffer_hash_size;
}
static inline unsigned int efx_rx_buf_size(struct efx_nic *efx)
{
@@ -193,6 +189,7 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
struct efx_rx_buffer *rx_buf;
struct page *page;
void *page_addr;
+ unsigned int page_offset;
struct efx_rx_page_state *state;
dma_addr_t dma_addr;
unsigned index, count;
@@ -219,12 +216,14 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
page_addr += sizeof(struct efx_rx_page_state);
dma_addr += sizeof(struct efx_rx_page_state);
+ page_offset = sizeof(struct efx_rx_page_state);
split:
index = rx_queue->added_count & rx_queue->ptr_mask;
rx_buf = efx_rx_buffer(rx_queue, index);
rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN;
rx_buf->u.page = page;
+ rx_buf->page_offset = page_offset + EFX_PAGE_IP_ALIGN;
rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
rx_buf->is_page = true;
++rx_queue->added_count;
@@ -236,6 +235,7 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
get_page(page);
dma_addr += (PAGE_SIZE >> 1);
page_addr += (PAGE_SIZE >> 1);
+ page_offset += (PAGE_SIZE >> 1);
++count;
goto split;
}