sfc: Refactor struct efx_tx_buffer to use a flags field
Add a flags field to struct efx_tx_buffer, replacing the
continuation and map_single booleans.
Since a single descriptor cannot be both a TSO header and the last
descriptor for an skb, unionise efx_tx_buffer::{skb,tsoh} and add
flags for validity of these fields.
Clear all flags in free buffers (whereas previously the continuation
flag would be set).
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 1871343..24c82f3 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -39,25 +39,25 @@
struct device *dma_dev = &tx_queue->efx->pci_dev->dev;
dma_addr_t unmap_addr = (buffer->dma_addr + buffer->len -
buffer->unmap_len);
- if (buffer->unmap_single)
+ if (buffer->flags & EFX_TX_BUF_MAP_SINGLE)
dma_unmap_single(dma_dev, unmap_addr, buffer->unmap_len,
DMA_TO_DEVICE);
else
dma_unmap_page(dma_dev, unmap_addr, buffer->unmap_len,
DMA_TO_DEVICE);
buffer->unmap_len = 0;
- buffer->unmap_single = false;
}
- if (buffer->skb) {
+ if (buffer->flags & EFX_TX_BUF_SKB) {
(*pkts_compl)++;
(*bytes_compl) += buffer->skb->len;
dev_kfree_skb_any((struct sk_buff *) buffer->skb);
- buffer->skb = NULL;
netif_vdbg(tx_queue->efx, tx_done, tx_queue->efx->net_dev,
"TX queue %d transmission id %x complete\n",
tx_queue->queue, tx_queue->read_count);
}
+
+ buffer->flags &= EFX_TX_BUF_TSOH;
}
/**
@@ -89,14 +89,14 @@
static void efx_tsoh_free(struct efx_tx_queue *tx_queue,
struct efx_tx_buffer *buffer)
{
- if (buffer->tsoh) {
+ if (buffer->flags & EFX_TX_BUF_TSOH) {
if (likely(!buffer->tsoh->unmap_len)) {
buffer->tsoh->next = tx_queue->tso_headers_free;
tx_queue->tso_headers_free = buffer->tsoh;
} else {
efx_tsoh_heap_free(tx_queue, buffer->tsoh);
}
- buffer->tsoh = NULL;
+ buffer->flags &= ~EFX_TX_BUF_TSOH;
}
}
@@ -163,7 +163,7 @@
unsigned int len, unmap_len = 0, fill_level, insert_ptr;
dma_addr_t dma_addr, unmap_addr = 0;
unsigned int dma_len;
- bool unmap_single;
+ unsigned short dma_flags;
int q_space, i = 0;
netdev_tx_t rc = NETDEV_TX_OK;
@@ -190,7 +190,7 @@
* since this is more efficient on machines with sparse
* memory.
*/
- unmap_single = true;
+ dma_flags = EFX_TX_BUF_MAP_SINGLE;
dma_addr = dma_map_single(dma_dev, skb->data, len, PCI_DMA_TODEVICE);
/* Process all fragments */
@@ -234,10 +234,8 @@
insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
buffer = &tx_queue->buffer[insert_ptr];
efx_tsoh_free(tx_queue, buffer);
- EFX_BUG_ON_PARANOID(buffer->tsoh);
- EFX_BUG_ON_PARANOID(buffer->skb);
+ EFX_BUG_ON_PARANOID(buffer->flags);
EFX_BUG_ON_PARANOID(buffer->len);
- EFX_BUG_ON_PARANOID(!buffer->continuation);
EFX_BUG_ON_PARANOID(buffer->unmap_len);
dma_len = efx_max_tx_len(efx, dma_addr);
@@ -247,13 +245,14 @@
/* Fill out per descriptor fields */
buffer->len = dma_len;
buffer->dma_addr = dma_addr;
+ buffer->flags = EFX_TX_BUF_CONT;
len -= dma_len;
dma_addr += dma_len;
++tx_queue->insert_count;
} while (len);
/* Transfer ownership of the unmapping to the final buffer */
- buffer->unmap_single = unmap_single;
+ buffer->flags = EFX_TX_BUF_CONT | dma_flags;
buffer->unmap_len = unmap_len;
unmap_len = 0;
@@ -264,14 +263,14 @@
len = skb_frag_size(fragment);
i++;
/* Map for DMA */
- unmap_single = false;
+ dma_flags = 0;
dma_addr = skb_frag_dma_map(dma_dev, fragment, 0, len,
DMA_TO_DEVICE);
}
/* Transfer ownership of the skb to the final buffer */
buffer->skb = skb;
- buffer->continuation = false;
+ buffer->flags = EFX_TX_BUF_SKB | dma_flags;
netdev_tx_sent_queue(tx_queue->core_txq, skb->len);
@@ -302,7 +301,7 @@
/* Free the fragment we were mid-way through pushing */
if (unmap_len) {
- if (unmap_single)
+ if (dma_flags & EFX_TX_BUF_MAP_SINGLE)
dma_unmap_single(dma_dev, unmap_addr, unmap_len,
DMA_TO_DEVICE);
else
@@ -340,7 +339,6 @@
}
efx_dequeue_buffer(tx_queue, buffer, pkts_compl, bytes_compl);
- buffer->continuation = true;
buffer->len = 0;
++tx_queue->read_count;
@@ -484,7 +482,7 @@
{
struct efx_nic *efx = tx_queue->efx;
unsigned int entries;
- int i, rc;
+ int rc;
/* Create the smallest power-of-two aligned ring */
entries = max(roundup_pow_of_two(efx->txq_entries), EFX_MIN_DMAQ_SIZE);
@@ -500,8 +498,6 @@
GFP_KERNEL);
if (!tx_queue->buffer)
return -ENOMEM;
- for (i = 0; i <= tx_queue->ptr_mask; ++i)
- tx_queue->buffer[i].continuation = true;
/* Allocate hardware ring */
rc = efx_nic_probe_tx(tx_queue);
@@ -546,7 +542,6 @@
unsigned int pkts_compl = 0, bytes_compl = 0;
buffer = &tx_queue->buffer[tx_queue->read_count & tx_queue->ptr_mask];
efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl);
- buffer->continuation = true;
buffer->len = 0;
++tx_queue->read_count;
@@ -631,7 +626,7 @@
* @in_len: Remaining length in current SKB fragment
* @unmap_len: Length of SKB fragment
* @unmap_addr: DMA address of SKB fragment
- * @unmap_single: DMA single vs page mapping flag
+ * @dma_flags: TX buffer flags for DMA mapping - %EFX_TX_BUF_MAP_SINGLE or 0
* @protocol: Network protocol (after any VLAN header)
* @header_len: Number of bytes of header
* @full_packet_size: Number of bytes to put in each outgoing segment
@@ -651,7 +646,7 @@
unsigned in_len;
unsigned unmap_len;
dma_addr_t unmap_addr;
- bool unmap_single;
+ unsigned short dma_flags;
__be16 protocol;
unsigned header_len;
@@ -833,9 +828,7 @@
efx_tsoh_free(tx_queue, buffer);
EFX_BUG_ON_PARANOID(buffer->len);
EFX_BUG_ON_PARANOID(buffer->unmap_len);
- EFX_BUG_ON_PARANOID(buffer->skb);
- EFX_BUG_ON_PARANOID(!buffer->continuation);
- EFX_BUG_ON_PARANOID(buffer->tsoh);
+ EFX_BUG_ON_PARANOID(buffer->flags);
buffer->dma_addr = dma_addr;
@@ -845,7 +838,8 @@
if (dma_len >= len)
break;
- buffer->len = dma_len; /* Don't set the other members */
+ buffer->len = dma_len;
+ buffer->flags = EFX_TX_BUF_CONT;
dma_addr += dma_len;
len -= dma_len;
}
@@ -873,12 +867,11 @@
efx_tsoh_free(tx_queue, buffer);
EFX_BUG_ON_PARANOID(buffer->len);
EFX_BUG_ON_PARANOID(buffer->unmap_len);
- EFX_BUG_ON_PARANOID(buffer->skb);
- EFX_BUG_ON_PARANOID(!buffer->continuation);
- EFX_BUG_ON_PARANOID(buffer->tsoh);
+ EFX_BUG_ON_PARANOID(buffer->flags);
buffer->len = len;
buffer->dma_addr = tsoh->dma_addr;
buffer->tsoh = tsoh;
+ buffer->flags = EFX_TX_BUF_TSOH | EFX_TX_BUF_CONT;
++tx_queue->insert_count;
}
@@ -896,11 +889,11 @@
buffer = &tx_queue->buffer[tx_queue->insert_count &
tx_queue->ptr_mask];
efx_tsoh_free(tx_queue, buffer);
- EFX_BUG_ON_PARANOID(buffer->skb);
+ EFX_BUG_ON_PARANOID(buffer->flags & EFX_TX_BUF_SKB);
if (buffer->unmap_len) {
unmap_addr = (buffer->dma_addr + buffer->len -
buffer->unmap_len);
- if (buffer->unmap_single)
+ if (buffer->flags & EFX_TX_BUF_MAP_SINGLE)
dma_unmap_single(&tx_queue->efx->pci_dev->dev,
unmap_addr, buffer->unmap_len,
DMA_TO_DEVICE);
@@ -911,7 +904,7 @@
buffer->unmap_len = 0;
}
buffer->len = 0;
- buffer->continuation = true;
+ buffer->flags = 0;
}
}
@@ -938,7 +931,7 @@
st->out_len = skb->len - st->header_len;
st->unmap_len = 0;
- st->unmap_single = false;
+ st->dma_flags = 0;
}
static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
@@ -947,7 +940,7 @@
st->unmap_addr = skb_frag_dma_map(&efx->pci_dev->dev, frag, 0,
skb_frag_size(frag), DMA_TO_DEVICE);
if (likely(!dma_mapping_error(&efx->pci_dev->dev, st->unmap_addr))) {
- st->unmap_single = false;
+ st->dma_flags = 0;
st->unmap_len = skb_frag_size(frag);
st->in_len = skb_frag_size(frag);
st->dma_addr = st->unmap_addr;
@@ -965,7 +958,7 @@
st->unmap_addr = dma_map_single(&efx->pci_dev->dev, skb->data + hl,
len, DMA_TO_DEVICE);
if (likely(!dma_mapping_error(&efx->pci_dev->dev, st->unmap_addr))) {
- st->unmap_single = true;
+ st->dma_flags = EFX_TX_BUF_MAP_SINGLE;
st->unmap_len = len;
st->in_len = len;
st->dma_addr = st->unmap_addr;
@@ -990,7 +983,7 @@
struct tso_state *st)
{
struct efx_tx_buffer *buffer;
- int n, end_of_packet, rc;
+ int n, rc;
if (st->in_len == 0)
return 0;
@@ -1008,17 +1001,18 @@
rc = efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer);
if (likely(rc == 0)) {
- if (st->out_len == 0)
+ if (st->out_len == 0) {
/* Transfer ownership of the skb */
buffer->skb = skb;
-
- end_of_packet = st->out_len == 0 || st->packet_space == 0;
- buffer->continuation = !end_of_packet;
+ buffer->flags = EFX_TX_BUF_SKB;
+ } else if (st->packet_space != 0) {
+ buffer->flags = EFX_TX_BUF_CONT;
+ }
if (st->in_len == 0) {
/* Transfer ownership of the DMA mapping */
buffer->unmap_len = st->unmap_len;
- buffer->unmap_single = st->unmap_single;
+ buffer->flags |= st->dma_flags;
st->unmap_len = 0;
}
}
@@ -1195,7 +1189,7 @@
unwind:
/* Free the DMA mapping we were in the process of writing out */
if (state.unmap_len) {
- if (state.unmap_single)
+ if (state.dma_flags & EFX_TX_BUF_MAP_SINGLE)
dma_unmap_single(&efx->pci_dev->dev, state.unmap_addr,
state.unmap_len, DMA_TO_DEVICE);
else