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authorBen Hutchings <bhutchings@solarflare.com>2008-09-01 12:46:40 +0100
committerJeff Garzik <jgarzik@redhat.com>2008-09-03 09:53:44 -0400
commitecbd95c17c221913cc3c5776051b2fa8b3b97316 (patch)
tree1ec0daca41be682886639a8dc3627edbe7571523 /drivers/net/sfc/tx.c
parent5988b63a53e120a9db4439d4512f4c1b17e7170e (diff)
sfc: Use pci_map_single() to map the skb header when doing TSO
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/net/sfc/tx.c')
-rw-r--r--drivers/net/sfc/tx.c152
1 files changed, 83 insertions, 69 deletions
diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
index 0452ea6937a..11127757c05 100644
--- a/drivers/net/sfc/tx.c
+++ b/drivers/net/sfc/tx.c
@@ -287,9 +287,14 @@ static inline int efx_enqueue_skb(struct efx_tx_queue *tx_queue,
}
/* Free the fragment we were mid-way through pushing */
- if (unmap_len)
- pci_unmap_page(pci_dev, unmap_addr, unmap_len,
- PCI_DMA_TODEVICE);
+ if (unmap_len) {
+ if (unmap_single)
+ pci_unmap_single(pci_dev, unmap_addr, unmap_len,
+ PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(pci_dev, unmap_addr, unmap_len,
+ PCI_DMA_TODEVICE);
+ }
return rc;
}
@@ -561,8 +566,7 @@ struct tso_state {
/* DMA address and length of the whole fragment */
unsigned int unmap_len;
dma_addr_t unmap_addr;
- struct page *page;
- unsigned page_off;
+ unsigned int unmap_single;
} ifc;
struct {
@@ -686,18 +690,14 @@ efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, struct efx_tso_header *tsoh)
* @tx_queue: Efx TX queue
* @dma_addr: DMA address of fragment
* @len: Length of fragment
- * @skb: Only non-null for end of last segment
- * @end_of_packet: True if last fragment in a packet
- * @unmap_addr: DMA address of fragment for unmapping
- * @unmap_len: Only set this in last segment of a fragment
+ * @final_buffer: The final buffer inserted into the queue
*
* Push descriptors onto the TX queue. Return 0 on success or 1 if
* @tx_queue full.
*/
static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
dma_addr_t dma_addr, unsigned len,
- const struct sk_buff *skb, int end_of_packet,
- dma_addr_t unmap_addr, unsigned unmap_len)
+ struct efx_tx_buffer **final_buffer)
{
struct efx_tx_buffer *buffer;
struct efx_nic *efx = tx_queue->efx;
@@ -725,8 +725,10 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
fill_level = (tx_queue->insert_count
- tx_queue->old_read_count);
q_space = efx->type->txd_ring_mask - 1 - fill_level;
- if (unlikely(q_space-- <= 0))
+ if (unlikely(q_space-- <= 0)) {
+ *final_buffer = NULL;
return 1;
+ }
smp_mb();
--tx_queue->stopped;
}
@@ -766,10 +768,7 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
EFX_BUG_ON_PARANOID(!len);
buffer->len = len;
- buffer->skb = skb;
- buffer->continuation = !end_of_packet;
- buffer->unmap_addr = unmap_addr;
- buffer->unmap_len = unmap_len;
+ *final_buffer = buffer;
return 0;
}
@@ -817,9 +816,16 @@ static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
buffer->len = 0;
buffer->continuation = 1;
if (buffer->unmap_len) {
- pci_unmap_page(tx_queue->efx->pci_dev,
- buffer->unmap_addr,
- buffer->unmap_len, PCI_DMA_TODEVICE);
+ if (buffer->unmap_single)
+ pci_unmap_single(tx_queue->efx->pci_dev,
+ buffer->unmap_addr,
+ buffer->unmap_len,
+ PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(tx_queue->efx->pci_dev,
+ buffer->unmap_addr,
+ buffer->unmap_len,
+ PCI_DMA_TODEVICE);
buffer->unmap_len = 0;
}
}
@@ -846,31 +852,40 @@ static inline void tso_start(struct tso_state *st, const struct sk_buff *skb)
st->packet_space = st->p.full_packet_size;
st->remaining_len = skb->len - st->p.header_length;
+ st->ifc.unmap_len = 0;
+ st->ifc.unmap_single = 0;
}
-
-/**
- * tso_get_fragment - record fragment details and map for DMA
- * @st: TSO state
- * @efx: Efx NIC
- * @data: Pointer to fragment data
- * @len: Length of fragment
- *
- * Record fragment details and map for DMA. Return 0 on success, or
- * -%ENOMEM if DMA mapping fails.
- */
static inline int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
- int len, struct page *page, int page_off)
+ skb_frag_t *frag)
{
+ st->ifc.unmap_addr = pci_map_page(efx->pci_dev, frag->page,
+ frag->page_offset, frag->size,
+ PCI_DMA_TODEVICE);
+ if (likely(!pci_dma_mapping_error(efx->pci_dev, st->ifc.unmap_addr))) {
+ st->ifc.unmap_single = 0;
+ st->ifc.unmap_len = frag->size;
+ st->ifc.len = frag->size;
+ st->ifc.dma_addr = st->ifc.unmap_addr;
+ return 0;
+ }
+ return -ENOMEM;
+}
+
+static inline int
+tso_get_head_fragment(struct tso_state *st, struct efx_nic *efx,
+ const struct sk_buff *skb)
+{
+ int hl = st->p.header_length;
+ int len = skb_headlen(skb) - hl;
- st->ifc.unmap_addr = pci_map_page(efx->pci_dev, page, page_off,
- len, PCI_DMA_TODEVICE);
+ st->ifc.unmap_addr = pci_map_single(efx->pci_dev, skb->data + hl,
+ len, PCI_DMA_TODEVICE);
if (likely(!pci_dma_mapping_error(efx->pci_dev, st->ifc.unmap_addr))) {
+ st->ifc.unmap_single = 1;
st->ifc.unmap_len = len;
st->ifc.len = len;
st->ifc.dma_addr = st->ifc.unmap_addr;
- st->ifc.page = page;
- st->ifc.page_off = page_off;
return 0;
}
return -ENOMEM;
@@ -891,7 +906,7 @@ static inline int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue,
const struct sk_buff *skb,
struct tso_state *st)
{
-
+ struct efx_tx_buffer *buffer;
int n, end_of_packet, rc;
if (st->ifc.len == 0)
@@ -907,16 +922,25 @@ static inline int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue,
st->packet_space -= n;
st->remaining_len -= n;
st->ifc.len -= n;
- st->ifc.page_off += n;
- end_of_packet = st->remaining_len == 0 || st->packet_space == 0;
- rc = efx_tx_queue_insert(tx_queue, st->ifc.dma_addr, n,
- st->remaining_len ? NULL : skb,
- end_of_packet, st->ifc.unmap_addr,
- st->ifc.len ? 0 : st->ifc.unmap_len);
+ rc = efx_tx_queue_insert(tx_queue, st->ifc.dma_addr, n, &buffer);
+ if (likely(rc == 0)) {
+ if (st->remaining_len == 0)
+ /* Transfer ownership of the skb */
+ buffer->skb = skb;
- st->ifc.dma_addr += n;
+ end_of_packet = st->remaining_len == 0 || st->packet_space == 0;
+ buffer->continuation = !end_of_packet;
+ if (st->ifc.len == 0) {
+ /* Transfer ownership of the pci mapping */
+ buffer->unmap_len = st->ifc.unmap_len;
+ buffer->unmap_single = st->ifc.unmap_single;
+ st->ifc.unmap_len = 0;
+ }
+ }
+
+ st->ifc.dma_addr += n;
return rc;
}
@@ -1008,9 +1032,9 @@ static inline int tso_start_new_packet(struct efx_tx_queue *tx_queue,
static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
const struct sk_buff *skb)
{
+ struct efx_nic *efx = tx_queue->efx;
int frag_i, rc, rc2 = NETDEV_TX_OK;
struct tso_state state;
- skb_frag_t *f;
/* Verify TSO is safe - these checks should never fail. */
efx_tso_check_safe(skb);
@@ -1026,25 +1050,12 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
/* Grab the first payload fragment. */
EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1);
frag_i = 0;
- f = &skb_shinfo(skb)->frags[frag_i];
- rc = tso_get_fragment(&state, tx_queue->efx,
- f->size, f->page, f->page_offset);
+ rc = tso_get_fragment(&state, efx,
+ skb_shinfo(skb)->frags + frag_i);
if (rc)
goto mem_err;
} else {
- /* It may look like this code fragment assumes that the
- * skb->data portion does not cross a page boundary, but
- * that is not the case. It is guaranteed to be direct
- * mapped memory, and therefore is physically contiguous,
- * and so DMA will work fine. kmap_atomic() on this region
- * will just return the direct mapping, so that will work
- * too.
- */
- int page_off = (unsigned long)skb->data & (PAGE_SIZE - 1);
- int hl = state.p.header_length;
- rc = tso_get_fragment(&state, tx_queue->efx,
- skb_headlen(skb) - hl,
- virt_to_page(skb->data), page_off + hl);
+ rc = tso_get_head_fragment(&state, efx, skb);
if (rc)
goto mem_err;
frag_i = -1;
@@ -1063,9 +1074,8 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
if (++frag_i >= skb_shinfo(skb)->nr_frags)
/* End of payload reached. */
break;
- f = &skb_shinfo(skb)->frags[frag_i];
- rc = tso_get_fragment(&state, tx_queue->efx,
- f->size, f->page, f->page_offset);
+ rc = tso_get_fragment(&state, efx,
+ skb_shinfo(skb)->frags + frag_i);
if (rc)
goto mem_err;
}
@@ -1083,8 +1093,7 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
return NETDEV_TX_OK;
mem_err:
- EFX_ERR(tx_queue->efx, "Out of memory for TSO headers, or PCI mapping"
- " error\n");
+ EFX_ERR(efx, "Out of memory for TSO headers, or PCI mapping error\n");
dev_kfree_skb_any((struct sk_buff *)skb);
goto unwind;
@@ -1093,13 +1102,18 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
/* Stop the queue if it wasn't stopped before. */
if (tx_queue->stopped == 1)
- efx_stop_queue(tx_queue->efx);
+ efx_stop_queue(efx);
unwind:
/* Free the DMA mapping we were in the process of writing out */
- if (state.ifc.unmap_len)
- pci_unmap_page(tx_queue->efx->pci_dev, state.ifc.unmap_addr,
- state.ifc.unmap_len, PCI_DMA_TODEVICE);
+ if (state.ifc.unmap_len) {
+ if (state.ifc.unmap_single)
+ pci_unmap_single(efx->pci_dev, state.ifc.unmap_addr,
+ state.ifc.unmap_len, PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(efx->pci_dev, state.ifc.unmap_addr,
+ state.ifc.unmap_len, PCI_DMA_TODEVICE);
+ }
efx_enqueue_unwind(tx_queue);
return rc2;