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path: root/drivers/net/ethernet/sfc/tx.c
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Diffstat (limited to 'drivers/net/ethernet/sfc/tx.c')
-rw-r--r--drivers/net/ethernet/sfc/tx.c621
1 files changed, 245 insertions, 376 deletions
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 18713436b44..ebca75ed78d 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -22,14 +22,6 @@
#include "nic.h"
#include "workarounds.h"
-/*
- * TX descriptor ring full threshold
- *
- * The tx_queue descriptor ring fill-level must fall below this value
- * before we restart the netif queue
- */
-#define EFX_TXQ_THRESHOLD(_efx) ((_efx)->txq_entries / 2u)
-
static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue,
struct efx_tx_buffer *buffer,
unsigned int *pkts_compl,
@@ -39,67 +31,32 @@ static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue,
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);
+ } else if (buffer->flags & EFX_TX_BUF_HEAP) {
+ kfree(buffer->heap_buf);
}
-}
-/**
- * struct efx_tso_header - a DMA mapped buffer for packet headers
- * @next: Linked list of free ones.
- * The list is protected by the TX queue lock.
- * @dma_unmap_len: Length to unmap for an oversize buffer, or 0.
- * @dma_addr: The DMA address of the header below.
- *
- * This controls the memory used for a TSO header. Use TSOH_DATA()
- * to find the packet header data. Use TSOH_SIZE() to calculate the
- * total size required for a given packet header length. TSO headers
- * in the free list are exactly %TSOH_STD_SIZE bytes in size.
- */
-struct efx_tso_header {
- union {
- struct efx_tso_header *next;
- size_t unmap_len;
- };
- dma_addr_t dma_addr;
-};
+ buffer->len = 0;
+ buffer->flags = 0;
+}
static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
struct sk_buff *skb);
-static void efx_fini_tso(struct efx_tx_queue *tx_queue);
-static void efx_tsoh_heap_free(struct efx_tx_queue *tx_queue,
- struct efx_tso_header *tsoh);
-
-static void efx_tsoh_free(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer)
-{
- if (buffer->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;
- }
-}
-
static inline unsigned
efx_max_tx_len(struct efx_nic *efx, dma_addr_t dma_addr)
@@ -138,6 +95,56 @@ unsigned int efx_tx_max_skb_descs(struct efx_nic *efx)
return max_descs;
}
+/* Get partner of a TX queue, seen as part of the same net core queue */
+static struct efx_tx_queue *efx_tx_queue_partner(struct efx_tx_queue *tx_queue)
+{
+ if (tx_queue->queue & EFX_TXQ_TYPE_OFFLOAD)
+ return tx_queue - EFX_TXQ_TYPE_OFFLOAD;
+ else
+ return tx_queue + EFX_TXQ_TYPE_OFFLOAD;
+}
+
+static void efx_tx_maybe_stop_queue(struct efx_tx_queue *txq1)
+{
+ /* We need to consider both queues that the net core sees as one */
+ struct efx_tx_queue *txq2 = efx_tx_queue_partner(txq1);
+ struct efx_nic *efx = txq1->efx;
+ unsigned int fill_level;
+
+ fill_level = max(txq1->insert_count - txq1->old_read_count,
+ txq2->insert_count - txq2->old_read_count);
+ if (likely(fill_level < efx->txq_stop_thresh))
+ return;
+
+ /* We used the stale old_read_count above, which gives us a
+ * pessimistic estimate of the fill level (which may even
+ * validly be >= efx->txq_entries). Now try again using
+ * read_count (more likely to be a cache miss).
+ *
+ * If we read read_count and then conditionally stop the
+ * queue, it is possible for the completion path to race with
+ * us and complete all outstanding descriptors in the middle,
+ * after which there will be no more completions to wake it.
+ * Therefore we stop the queue first, then read read_count
+ * (with a memory barrier to ensure the ordering), then
+ * restart the queue if the fill level turns out to be low
+ * enough.
+ */
+ netif_tx_stop_queue(txq1->core_txq);
+ smp_mb();
+ txq1->old_read_count = ACCESS_ONCE(txq1->read_count);
+ txq2->old_read_count = ACCESS_ONCE(txq2->read_count);
+
+ fill_level = max(txq1->insert_count - txq1->old_read_count,
+ txq2->insert_count - txq2->old_read_count);
+ EFX_BUG_ON_PARANOID(fill_level >= efx->txq_entries);
+ if (likely(fill_level < efx->txq_stop_thresh)) {
+ smp_mb();
+ if (likely(!efx->loopback_selftest))
+ netif_tx_start_queue(txq1->core_txq);
+ }
+}
+
/*
* Add a socket buffer to a TX queue
*
@@ -151,7 +158,7 @@ unsigned int efx_tx_max_skb_descs(struct efx_nic *efx)
* This function is split out from efx_hard_start_xmit to allow the
* loopback test to direct packets via specific TX queues.
*
- * Returns NETDEV_TX_OK or NETDEV_TX_BUSY
+ * Returns NETDEV_TX_OK.
* You must hold netif_tx_lock() to call this function.
*/
netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
@@ -160,12 +167,11 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
struct device *dma_dev = &efx->pci_dev->dev;
struct efx_tx_buffer *buffer;
skb_frag_t *fragment;
- unsigned int len, unmap_len = 0, fill_level, insert_ptr;
+ unsigned int len, unmap_len = 0, insert_ptr;
dma_addr_t dma_addr, unmap_addr = 0;
unsigned int dma_len;
- bool unmap_single;
- int q_space, i = 0;
- netdev_tx_t rc = NETDEV_TX_OK;
+ unsigned short dma_flags;
+ int i = 0;
EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count);
@@ -183,14 +189,11 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
return NETDEV_TX_OK;
}
- fill_level = tx_queue->insert_count - tx_queue->old_read_count;
- q_space = efx->txq_entries - 1 - fill_level;
-
/* Map for DMA. Use dma_map_single rather than dma_map_page
* 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 */
@@ -205,39 +208,10 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
/* Add to TX queue, splitting across DMA boundaries */
do {
- if (unlikely(q_space-- <= 0)) {
- /* It might be that completions have
- * happened since the xmit path last
- * checked. Update the xmit path's
- * copy of read_count.
- */
- netif_tx_stop_queue(tx_queue->core_txq);
- /* This memory barrier protects the
- * change of queue state from the access
- * of read_count. */
- smp_mb();
- tx_queue->old_read_count =
- ACCESS_ONCE(tx_queue->read_count);
- fill_level = (tx_queue->insert_count
- - tx_queue->old_read_count);
- q_space = efx->txq_entries - 1 - fill_level;
- if (unlikely(q_space-- <= 0)) {
- rc = NETDEV_TX_BUSY;
- goto unwind;
- }
- smp_mb();
- if (likely(!efx->loopback_selftest))
- netif_tx_start_queue(
- tx_queue->core_txq);
- }
-
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 +221,14 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
/* 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;
@@ -264,20 +239,22 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
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);
/* Pass off to hardware */
efx_nic_push_buffers(tx_queue);
+ efx_tx_maybe_stop_queue(tx_queue);
+
return NETDEV_TX_OK;
dma_err:
@@ -289,7 +266,6 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
/* Mark the packet as transmitted, and free the SKB ourselves */
dev_kfree_skb_any(skb);
- unwind:
/* Work backwards until we hit the original insert pointer value */
while (tx_queue->insert_count != tx_queue->write_count) {
unsigned int pkts_compl = 0, bytes_compl = 0;
@@ -297,12 +273,11 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
buffer = &tx_queue->buffer[insert_ptr];
efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl);
- buffer->len = 0;
}
/* 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
@@ -310,7 +285,7 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
DMA_TO_DEVICE);
}
- return rc;
+ return NETDEV_TX_OK;
}
/* Remove packets from the TX queue
@@ -340,8 +315,6 @@ static void efx_dequeue_buffers(struct efx_tx_queue *tx_queue,
}
efx_dequeue_buffer(tx_queue, buffer, pkts_compl, bytes_compl);
- buffer->continuation = true;
- buffer->len = 0;
++tx_queue->read_count;
read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
@@ -450,6 +423,7 @@ void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index)
{
unsigned fill_level;
struct efx_nic *efx = tx_queue->efx;
+ struct efx_tx_queue *txq2;
unsigned int pkts_compl = 0, bytes_compl = 0;
EFX_BUG_ON_PARANOID(index > tx_queue->ptr_mask);
@@ -457,15 +431,18 @@ void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index)
efx_dequeue_buffers(tx_queue, index, &pkts_compl, &bytes_compl);
netdev_tx_completed_queue(tx_queue->core_txq, pkts_compl, bytes_compl);
- /* See if we need to restart the netif queue. This barrier
- * separates the update of read_count from the test of the
- * queue state. */
+ /* See if we need to restart the netif queue. This memory
+ * barrier ensures that we write read_count (inside
+ * efx_dequeue_buffers()) before reading the queue status.
+ */
smp_mb();
if (unlikely(netif_tx_queue_stopped(tx_queue->core_txq)) &&
likely(efx->port_enabled) &&
likely(netif_device_present(efx->net_dev))) {
- fill_level = tx_queue->insert_count - tx_queue->read_count;
- if (fill_level < EFX_TXQ_THRESHOLD(efx))
+ txq2 = efx_tx_queue_partner(tx_queue);
+ fill_level = max(tx_queue->insert_count - tx_queue->read_count,
+ txq2->insert_count - txq2->read_count);
+ if (fill_level <= efx->txq_wake_thresh)
netif_tx_wake_queue(tx_queue->core_txq);
}
@@ -480,11 +457,26 @@ void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index)
}
}
+/* Size of page-based TSO header buffers. Larger blocks must be
+ * allocated from the heap.
+ */
+#define TSOH_STD_SIZE 128
+#define TSOH_PER_PAGE (PAGE_SIZE / TSOH_STD_SIZE)
+
+/* At most half the descriptors in the queue at any time will refer to
+ * a TSO header buffer, since they must always be followed by a
+ * payload descriptor referring to an skb.
+ */
+static unsigned int efx_tsoh_page_count(struct efx_tx_queue *tx_queue)
+{
+ return DIV_ROUND_UP(tx_queue->ptr_mask + 1, 2 * TSOH_PER_PAGE);
+}
+
int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
{
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);
@@ -500,17 +492,28 @@ int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
GFP_KERNEL);
if (!tx_queue->buffer)
return -ENOMEM;
- for (i = 0; i <= tx_queue->ptr_mask; ++i)
- tx_queue->buffer[i].continuation = true;
+
+ if (tx_queue->queue & EFX_TXQ_TYPE_OFFLOAD) {
+ tx_queue->tsoh_page =
+ kcalloc(efx_tsoh_page_count(tx_queue),
+ sizeof(tx_queue->tsoh_page[0]), GFP_KERNEL);
+ if (!tx_queue->tsoh_page) {
+ rc = -ENOMEM;
+ goto fail1;
+ }
+ }
/* Allocate hardware ring */
rc = efx_nic_probe_tx(tx_queue);
if (rc)
- goto fail;
+ goto fail2;
return 0;
- fail:
+fail2:
+ kfree(tx_queue->tsoh_page);
+ tx_queue->tsoh_page = NULL;
+fail1:
kfree(tx_queue->buffer);
tx_queue->buffer = NULL;
return rc;
@@ -546,8 +549,6 @@ void efx_release_tx_buffers(struct efx_tx_queue *tx_queue)
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;
}
@@ -568,13 +569,12 @@ void efx_fini_tx_queue(struct efx_tx_queue *tx_queue)
efx_nic_fini_tx(tx_queue);
efx_release_tx_buffers(tx_queue);
-
- /* Free up TSO header cache */
- efx_fini_tso(tx_queue);
}
void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
{
+ int i;
+
if (!tx_queue->buffer)
return;
@@ -582,6 +582,14 @@ void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
"destroying TX queue %d\n", tx_queue->queue);
efx_nic_remove_tx(tx_queue);
+ if (tx_queue->tsoh_page) {
+ for (i = 0; i < efx_tsoh_page_count(tx_queue); i++)
+ efx_nic_free_buffer(tx_queue->efx,
+ &tx_queue->tsoh_page[i]);
+ kfree(tx_queue->tsoh_page);
+ tx_queue->tsoh_page = NULL;
+ }
+
kfree(tx_queue->buffer);
tx_queue->buffer = NULL;
}
@@ -604,22 +612,7 @@ void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
#define TSOH_OFFSET NET_IP_ALIGN
#endif
-#define TSOH_BUFFER(tsoh) ((u8 *)(tsoh + 1) + TSOH_OFFSET)
-
-/* Total size of struct efx_tso_header, buffer and padding */
-#define TSOH_SIZE(hdr_len) \
- (sizeof(struct efx_tso_header) + TSOH_OFFSET + hdr_len)
-
-/* Size of blocks on free list. Larger blocks must be allocated from
- * the heap.
- */
-#define TSOH_STD_SIZE 128
-
#define PTR_DIFF(p1, p2) ((u8 *)(p1) - (u8 *)(p2))
-#define ETH_HDR_LEN(skb) (skb_network_header(skb) - (skb)->data)
-#define SKB_TCP_OFF(skb) PTR_DIFF(tcp_hdr(skb), (skb)->data)
-#define SKB_IPV4_OFF(skb) PTR_DIFF(ip_hdr(skb), (skb)->data)
-#define SKB_IPV6_OFF(skb) PTR_DIFF(ipv6_hdr(skb), (skb)->data)
/**
* struct tso_state - TSO state for an SKB
@@ -631,10 +624,12 @@ void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
* @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)
+ * @ip_off: Offset of IP header
+ * @tcp_off: Offset of TCP header
* @header_len: Number of bytes of header
- * @full_packet_size: Number of bytes to put in each outgoing segment
+ * @ip_base_len: IPv4 tot_len or IPv6 payload_len, before TCP payload
*
* The state used during segmentation. It is put into this data structure
* just to make it easy to pass into inline functions.
@@ -651,11 +646,13 @@ struct tso_state {
unsigned in_len;
unsigned unmap_len;
dma_addr_t unmap_addr;
- bool unmap_single;
+ unsigned short dma_flags;
__be16 protocol;
+ unsigned int ip_off;
+ unsigned int tcp_off;
unsigned header_len;
- int full_packet_size;
+ unsigned int ip_base_len;
};
@@ -687,91 +684,43 @@ static __be16 efx_tso_check_protocol(struct sk_buff *skb)
return protocol;
}
-
-/*
- * Allocate a page worth of efx_tso_header structures, and string them
- * into the tx_queue->tso_headers_free linked list. Return 0 or -ENOMEM.
- */
-static int efx_tsoh_block_alloc(struct efx_tx_queue *tx_queue)
+static u8 *efx_tsoh_get_buffer(struct efx_tx_queue *tx_queue,
+ struct efx_tx_buffer *buffer, unsigned int len)
{
- struct device *dma_dev = &tx_queue->efx->pci_dev->dev;
- struct efx_tso_header *tsoh;
- dma_addr_t dma_addr;
- u8 *base_kva, *kva;
-
- base_kva = dma_alloc_coherent(dma_dev, PAGE_SIZE, &dma_addr, GFP_ATOMIC);
- if (base_kva == NULL) {
- netif_err(tx_queue->efx, tx_err, tx_queue->efx->net_dev,
- "Unable to allocate page for TSO headers\n");
- return -ENOMEM;
- }
-
- /* dma_alloc_coherent() allocates pages. */
- EFX_BUG_ON_PARANOID(dma_addr & (PAGE_SIZE - 1u));
-
- for (kva = base_kva; kva < base_kva + PAGE_SIZE; kva += TSOH_STD_SIZE) {
- tsoh = (struct efx_tso_header *)kva;
- tsoh->dma_addr = dma_addr + (TSOH_BUFFER(tsoh) - base_kva);
- tsoh->next = tx_queue->tso_headers_free;
- tx_queue->tso_headers_free = tsoh;
- }
-
- return 0;
-}
+ u8 *result;
+ EFX_BUG_ON_PARANOID(buffer->len);
+ EFX_BUG_ON_PARANOID(buffer->flags);
+ EFX_BUG_ON_PARANOID(buffer->unmap_len);
-/* Free up a TSO header, and all others in the same page. */
-static void efx_tsoh_block_free(struct efx_tx_queue *tx_queue,
- struct efx_tso_header *tsoh,
- struct device *dma_dev)
-{
- struct efx_tso_header **p;
- unsigned long base_kva;
- dma_addr_t base_dma;
-
- base_kva = (unsigned long)tsoh & PAGE_MASK;
- base_dma = tsoh->dma_addr & PAGE_MASK;
-
- p = &tx_queue->tso_headers_free;
- while (*p != NULL) {
- if (((unsigned long)*p & PAGE_MASK) == base_kva)
- *p = (*p)->next;
- else
- p = &(*p)->next;
- }
-
- dma_free_coherent(dma_dev, PAGE_SIZE, (void *)base_kva, base_dma);
-}
+ if (likely(len <= TSOH_STD_SIZE - TSOH_OFFSET)) {
+ unsigned index =
+ (tx_queue->insert_count & tx_queue->ptr_mask) / 2;
+ struct efx_buffer *page_buf =
+ &tx_queue->tsoh_page[index / TSOH_PER_PAGE];
+ unsigned offset =
+ TSOH_STD_SIZE * (index % TSOH_PER_PAGE) + TSOH_OFFSET;
+
+ if (unlikely(!page_buf->addr) &&
+ efx_nic_alloc_buffer(tx_queue->efx, page_buf, PAGE_SIZE))
+ return NULL;
+
+ result = (u8 *)page_buf->addr + offset;
+ buffer->dma_addr = page_buf->dma_addr + offset;
+ buffer->flags = EFX_TX_BUF_CONT;
+ } else {
+ tx_queue->tso_long_headers++;
-static struct efx_tso_header *
-efx_tsoh_heap_alloc(struct efx_tx_queue *tx_queue, size_t header_len)
-{
- struct efx_tso_header *tsoh;
-
- tsoh = kmalloc(TSOH_SIZE(header_len), GFP_ATOMIC | GFP_DMA);
- if (unlikely(!tsoh))
- return NULL;
-
- tsoh->dma_addr = dma_map_single(&tx_queue->efx->pci_dev->dev,
- TSOH_BUFFER(tsoh), header_len,
- DMA_TO_DEVICE);
- if (unlikely(dma_mapping_error(&tx_queue->efx->pci_dev->dev,
- tsoh->dma_addr))) {
- kfree(tsoh);
- return NULL;
+ buffer->heap_buf = kmalloc(TSOH_OFFSET + len, GFP_ATOMIC);
+ if (unlikely(!buffer->heap_buf))
+ return NULL;
+ result = (u8 *)buffer->heap_buf + TSOH_OFFSET;
+ buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_HEAP;
}
- tsoh->unmap_len = header_len;
- return tsoh;
-}
+ buffer->len = len;
-static void
-efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, struct efx_tso_header *tsoh)
-{
- dma_unmap_single(&tx_queue->efx->pci_dev->dev,
- tsoh->dma_addr, tsoh->unmap_len,
- DMA_TO_DEVICE);
- kfree(tsoh);
+ return result;
}
/**
@@ -781,47 +730,19 @@ efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, struct efx_tso_header *tsoh)
* @len: Length of 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.
+ * Push descriptors onto the TX queue.
*/
-static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
- dma_addr_t dma_addr, unsigned len,
- struct efx_tx_buffer **final_buffer)
+static void efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
+ dma_addr_t dma_addr, unsigned len,
+ struct efx_tx_buffer **final_buffer)
{
struct efx_tx_buffer *buffer;
struct efx_nic *efx = tx_queue->efx;
- unsigned dma_len, fill_level, insert_ptr;
- int q_space;
+ unsigned dma_len, insert_ptr;
EFX_BUG_ON_PARANOID(len <= 0);
- fill_level = tx_queue->insert_count - tx_queue->old_read_count;
- /* -1 as there is no way to represent all descriptors used */
- q_space = efx->txq_entries - 1 - fill_level;
-
while (1) {
- if (unlikely(q_space-- <= 0)) {
- /* It might be that completions have happened
- * since the xmit path last checked. Update
- * the xmit path's copy of read_count.
- */
- netif_tx_stop_queue(tx_queue->core_txq);
- /* This memory barrier protects the change of
- * queue state from the access of read_count. */
- smp_mb();
- tx_queue->old_read_count =
- ACCESS_ONCE(tx_queue->read_count);
- fill_level = (tx_queue->insert_count
- - tx_queue->old_read_count);
- q_space = efx->txq_entries - 1 - fill_level;
- if (unlikely(q_space-- <= 0)) {
- *final_buffer = NULL;
- return 1;
- }
- smp_mb();
- netif_tx_start_queue(tx_queue->core_txq);
- }
-
insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
buffer = &tx_queue->buffer[insert_ptr];
++tx_queue->insert_count;
@@ -830,12 +751,9 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
tx_queue->read_count >=
efx->txq_entries);
- 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 +763,8 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
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;
}
@@ -853,7 +772,6 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
EFX_BUG_ON_PARANOID(!len);
buffer->len = len;
*final_buffer = buffer;
- return 0;
}
@@ -864,54 +782,42 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
* a single fragment, and we know it doesn't cross a page boundary. It
* also allows us to not worry about end-of-packet etc.
*/
-static void efx_tso_put_header(struct efx_tx_queue *tx_queue,
- struct efx_tso_header *tsoh, unsigned len)
+static int efx_tso_put_header(struct efx_tx_queue *tx_queue,
+ struct efx_tx_buffer *buffer, u8 *header)
{
- struct efx_tx_buffer *buffer;
-
- buffer = &tx_queue->buffer[tx_queue->insert_count & tx_queue->ptr_mask];
- 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);
- buffer->len = len;
- buffer->dma_addr = tsoh->dma_addr;
- buffer->tsoh = tsoh;
+ if (unlikely(buffer->flags & EFX_TX_BUF_HEAP)) {
+ buffer->dma_addr = dma_map_single(&tx_queue->efx->pci_dev->dev,
+ header, buffer->len,
+ DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(&tx_queue->efx->pci_dev->dev,
+ buffer->dma_addr))) {
+ kfree(buffer->heap_buf);
+ buffer->len = 0;
+ buffer->flags = 0;
+ return -ENOMEM;
+ }
+ buffer->unmap_len = buffer->len;
+ buffer->flags |= EFX_TX_BUF_MAP_SINGLE;
+ }
++tx_queue->insert_count;
+ return 0;
}
-/* Remove descriptors put into a tx_queue. */
+/* Remove buffers put into a tx_queue. None of the buffers must have
+ * an skb attached.
+ */
static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
{
struct efx_tx_buffer *buffer;
- dma_addr_t unmap_addr;
/* Work backwards until we hit the original insert pointer value */
while (tx_queue->insert_count != tx_queue->write_count) {
--tx_queue->insert_count;
buffer = &tx_queue->buffer[tx_queue->insert_count &
tx_queue->ptr_mask];
- efx_tsoh_free(tx_queue, buffer);
- EFX_BUG_ON_PARANOID(buffer->skb);
- if (buffer->unmap_len) {
- unmap_addr = (buffer->dma_addr + buffer->len -
- buffer->unmap_len);
- if (buffer->unmap_single)
- dma_unmap_single(&tx_queue->efx->pci_dev->dev,
- unmap_addr, buffer->unmap_len,
- DMA_TO_DEVICE);
- else
- dma_unmap_page(&tx_queue->efx->pci_dev->dev,
- unmap_addr, buffer->unmap_len,
- DMA_TO_DEVICE);
- buffer->unmap_len = 0;
- }
- buffer->len = 0;
- buffer->continuation = true;
+ efx_dequeue_buffer(tx_queue, buffer, NULL, NULL);
}
}
@@ -919,17 +825,16 @@ static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
/* Parse the SKB header and initialise state. */
static void tso_start(struct tso_state *st, const struct sk_buff *skb)
{
- /* All ethernet/IP/TCP headers combined size is TCP header size
- * plus offset of TCP header relative to start of packet.
- */
- st->header_len = ((tcp_hdr(skb)->doff << 2u)
- + PTR_DIFF(tcp_hdr(skb), skb->data));
- st->full_packet_size = st->header_len + skb_shinfo(skb)->gso_size;
-
- if (st->protocol == htons(ETH_P_IP))
+ st->ip_off = skb_network_header(skb) - skb->data;
+ st->tcp_off = skb_transport_header(skb) - skb->data;
+ st->header_len = st->tcp_off + (tcp_hdr(skb)->doff << 2u);
+ if (st->protocol == htons(ETH_P_IP)) {
+ st->ip_base_len = st->header_len - st->ip_off;
st->ipv4_id = ntohs(ip_hdr(skb)->id);
- else
+ } else {
+ st->ip_base_len = st->header_len - st->tcp_off;
st->ipv4_id = 0;
+ }
st->seqnum = ntohl(tcp_hdr(skb)->seq);
EFX_BUG_ON_PARANOID(tcp_hdr(skb)->urg);
@@ -938,7 +843,7 @@ static void tso_start(struct tso_state *st, const struct sk_buff *skb)
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 +852,7 @@ static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
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 +870,7 @@ static int tso_get_head_fragment(struct tso_state *st, struct efx_nic *efx,
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;
@@ -982,20 +887,19 @@ static int tso_get_head_fragment(struct tso_state *st, struct efx_nic *efx,
* @st: TSO state
*
* Form descriptors for the current fragment, until we reach the end
- * of fragment or end-of-packet. Return 0 on success, 1 if not enough
- * space in @tx_queue.
+ * of fragment or end-of-packet.
*/
-static int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue,
- const struct sk_buff *skb,
- struct tso_state *st)
+static void 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;
+ int n;
if (st->in_len == 0)
- return 0;
+ return;
if (st->packet_space == 0)
- return 0;
+ return;
EFX_BUG_ON_PARANOID(st->in_len <= 0);
EFX_BUG_ON_PARANOID(st->packet_space <= 0);
@@ -1006,25 +910,24 @@ static int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue,
st->out_len -= n;
st->in_len -= n;
- rc = efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer);
- if (likely(rc == 0)) {
- if (st->out_len == 0)
- /* Transfer ownership of the skb */
- buffer->skb = skb;
+ efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer);
- end_of_packet = st->out_len == 0 || st->packet_space == 0;
- buffer->continuation = !end_of_packet;
+ if (st->out_len == 0) {
+ /* Transfer ownership of the skb */
+ buffer->skb = skb;
+ 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;
- st->unmap_len = 0;
- }
+ if (st->in_len == 0) {
+ /* Transfer ownership of the DMA mapping */
+ buffer->unmap_len = st->unmap_len;
+ buffer->flags |= st->dma_flags;
+ st->unmap_len = 0;
}
st->dma_addr += n;
- return rc;
}
@@ -1035,36 +938,25 @@ static int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue,
* @st: TSO state
*
* Generate a new header and prepare for the new packet. Return 0 on
- * success, or -1 if failed to alloc header.
+ * success, or -%ENOMEM if failed to alloc header.
*/
static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
const struct sk_buff *skb,
struct tso_state *st)
{
- struct efx_tso_header *tsoh;
+ struct efx_tx_buffer *buffer =
+ &tx_queue->buffer[tx_queue->insert_count & tx_queue->ptr_mask];
struct tcphdr *tsoh_th;
unsigned ip_length;
u8 *header;
+ int rc;
- /* Allocate a DMA-mapped header buffer. */
- if (likely(TSOH_SIZE(st->header_len) <= TSOH_STD_SIZE)) {
- if (tx_queue->tso_headers_free == NULL) {
- if (efx_tsoh_block_alloc(tx_queue))
- return -1;
- }
- EFX_BUG_ON_PARANOID(!tx_queue->tso_headers_free);
- tsoh = tx_queue->tso_headers_free;
- tx_queue->tso_headers_free = tsoh->next;
- tsoh->unmap_len = 0;
- } else {
- tx_queue->tso_long_headers++;
- tsoh = efx_tsoh_heap_alloc(tx_queue, st->header_len);
- if (unlikely(!tsoh))
- return -1;
- }
+ /* Allocate and insert a DMA-mapped header buffer. */
+ header = efx_tsoh_get_buffer(tx_queue, buffer, st->header_len);
+ if (!header)
+ return -ENOMEM;
- header = TSOH_BUFFER(tsoh);
- tsoh_th = (struct tcphdr *)(header + SKB_TCP_OFF(skb));
+ tsoh_th = (struct tcphdr *)(header + st->tcp_off);
/* Copy and update the headers. */
memcpy(header, skb->data, st->header_len);
@@ -1073,19 +965,19 @@ static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
st->seqnum += skb_shinfo(skb)->gso_size;
if (st->out_len > skb_shinfo(skb)->gso_size) {
/* This packet will not finish the TSO burst. */
- ip_length = st->full_packet_size - ETH_HDR_LEN(skb);
+ st->packet_space = skb_shinfo(skb)->gso_size;
tsoh_th->fin = 0;
tsoh_th->psh = 0;
} else {
/* This packet will be the last in the TSO burst. */
- ip_length = st->header_len - ETH_HDR_LEN(skb) + st->out_len;
+ st->packet_space = st->out_len;
tsoh_th->fin = tcp_hdr(skb)->fin;
tsoh_th->psh = tcp_hdr(skb)->psh;
}
+ ip_length = st->ip_base_len + st->packet_space;
if (st->protocol == htons(ETH_P_IP)) {
- struct iphdr *tsoh_iph =
- (struct iphdr *)(header + SKB_IPV4_OFF(skb));
+ struct iphdr *tsoh_iph = (struct iphdr *)(header + st->ip_off);
tsoh_iph->tot_len = htons(ip_length);
@@ -1094,16 +986,16 @@ static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
st->ipv4_id++;
} else {
struct ipv6hdr *tsoh_iph =
- (struct ipv6hdr *)(header + SKB_IPV6_OFF(skb));
+ (struct ipv6hdr *)(header + st->ip_off);
- tsoh_iph->payload_len = htons(ip_length - sizeof(*tsoh_iph));
+ tsoh_iph->payload_len = htons(ip_length);
}
- st->packet_space = skb_shinfo(skb)->gso_size;
- ++tx_queue->tso_packets;
+ rc = efx_tso_put_header(tx_queue, buffer, header);
+ if (unlikely(rc))
+ return rc;
- /* Form a descriptor for this header. */
- efx_tso_put_header(tx_queue, tsoh, st->header_len);
+ ++tx_queue->tso_packets;
return 0;
}
@@ -1118,13 +1010,13 @@ static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
*
* Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if
* @skb was not enqueued. In all cases @skb is consumed. Return
- * %NETDEV_TX_OK or %NETDEV_TX_BUSY.
+ * %NETDEV_TX_OK.
*/
static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
struct sk_buff *skb)
{
struct efx_nic *efx = tx_queue->efx;
- int frag_i, rc, rc2 = NETDEV_TX_OK;
+ int frag_i, rc;
struct tso_state state;
/* Find the packet protocol and sanity-check it */
@@ -1156,11 +1048,7 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
goto mem_err;
while (1) {
- rc = tso_fill_packet_with_fragment(tx_queue, skb, &state);
- if (unlikely(rc)) {
- rc2 = NETDEV_TX_BUSY;
- goto unwind;
- }
+ tso_fill_packet_with_fragment(tx_queue, skb, &state);
/* Move onto the next fragment? */
if (state.in_len == 0) {
@@ -1184,6 +1072,8 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
/* Pass off to hardware */
efx_nic_push_buffers(tx_queue);
+ efx_tx_maybe_stop_queue(tx_queue);
+
tx_queue->tso_bursts++;
return NETDEV_TX_OK;
@@ -1192,10 +1082,9 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
"Out of memory for TSO headers, or DMA mapping error\n");
dev_kfree_skb_any(skb);
- 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
@@ -1204,25 +1093,5 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
}
efx_enqueue_unwind(tx_queue);
- return rc2;
-}
-
-
-/*
- * Free up all TSO datastructures associated with tx_queue. This
- * routine should be called only once the tx_queue is both empty and
- * will no longer be used.
- */
-static void efx_fini_tso(struct efx_tx_queue *tx_queue)
-{
- unsigned i;
-
- if (tx_queue->buffer) {
- for (i = 0; i <= tx_queue->ptr_mask; ++i)
- efx_tsoh_free(tx_queue, &tx_queue->buffer[i]);
- }
-
- while (tx_queue->tso_headers_free != NULL)
- efx_tsoh_block_free(tx_queue, tx_queue->tso_headers_free,
- &tx_queue->efx->pci_dev->dev);
+ return NETDEV_TX_OK;
}