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authorBen Hutchings <bhutchings@solarflare.com>2013-01-10 23:51:54 +0000
committerBen Hutchings <bhutchings@solarflare.com>2013-02-26 14:57:16 +0000
commitb590ace09d51cd39744e0f7662c5e4a0d1b5d952 (patch)
treec83ba26d5cc2e970c271f46d64b47e9767bce908
parent3a68f19d7afb80f548d016effbc6ed52643a8085 (diff)
sfc: Fix efx_rx_buf_offset() in the presence of swiotlb
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>
-rw-r--r--drivers/net/ethernet/sfc/net_driver.h4
-rw-r--r--drivers/net/ethernet/sfc/rx.c10
2 files changed, 8 insertions, 6 deletions
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 2d756c1d714..0a90abd2421 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -210,6 +210,7 @@ struct efx_tx_queue {
* Will be %NULL if the buffer slot is currently free.
* @page: The associated page buffer. Valif iff @flags & %EFX_RX_BUF_PAGE.
* Will be %NULL if the buffer slot is currently free.
+ * @page_offset: Offset within page. Valid iff @flags & %EFX_RX_BUF_PAGE.
* @len: Buffer length, in bytes.
* @flags: Flags for buffer and packet state.
*/
@@ -219,7 +220,8 @@ struct efx_rx_buffer {
struct sk_buff *skb;
struct page *page;
} u;
- unsigned int len;
+ u16 page_offset;
+ u16 len;
u16 flags;
};
#define EFX_RX_BUF_PAGE 0x0001
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index a5754916478..879ff5849bb 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -90,11 +90,7 @@ static unsigned int rx_refill_threshold;
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 ((unsigned int) 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)
{
@@ -187,6 +183,7 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
struct efx_nic *efx = rx_queue->efx;
struct efx_rx_buffer *rx_buf;
struct page *page;
+ unsigned int page_offset;
struct efx_rx_page_state *state;
dma_addr_t dma_addr;
unsigned index, count;
@@ -211,12 +208,14 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
state->dma_addr = dma_addr;
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;
rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
rx_buf->flags = EFX_RX_BUF_PAGE;
++rx_queue->added_count;
@@ -227,6 +226,7 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
/* Use the second half of the page */
get_page(page);
dma_addr += (PAGE_SIZE >> 1);
+ page_offset += (PAGE_SIZE >> 1);
++count;
goto split;
}