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authorBert Kenward <bkenward@solarflare.com>2016-11-17 10:51:54 +0000
committerDavid S. Miller <davem@davemloft.net>2016-11-18 11:55:38 -0500
commite9117e5099ea29592c2a6180f368951948837a8b (patch)
tree865d0862309b88b06a249b3cc949aee1589ba7ef /drivers/net/ethernet/sfc/tx.c
parentsfc: Update EF10 register definitions (diff)
downloadlinux-dev-e9117e5099ea29592c2a6180f368951948837a8b.tar.xz
linux-dev-e9117e5099ea29592c2a6180f368951948837a8b.zip
sfc: Firmware-Assisted TSO version 2
Add support for FATSOv2 to the driver. FATSOv2 offloads far more of the task of TCP segmentation to the firmware, such that we now just pass a single super-packet to the NIC. This means TSO has a great deal in common with a normal DMA transmit, apart from adding a couple of option descriptors. NIC-specific checks have been moved off the fast path and in to initialisation where possible. This also moves FATSOv1/SWTSO to a new file (tx_tso.c). The end of transmit and some error handling is now outside TSO, since it is common with other code. Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/sfc/tx.c')
-rw-r--r--drivers/net/ethernet/sfc/tx.c1013
1 files changed, 251 insertions, 762 deletions
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 233778911557..3089e888a08d 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -22,6 +22,7 @@
#include "efx.h"
#include "io.h"
#include "nic.h"
+#include "tx.h"
#include "workarounds.h"
#include "ef10_regs.h"
@@ -33,29 +34,30 @@ unsigned int efx_piobuf_size __read_mostly = EFX_PIOBUF_SIZE_DEF;
#endif /* EFX_USE_PIO */
-static inline unsigned int
-efx_tx_queue_get_insert_index(const struct efx_tx_queue *tx_queue)
+static inline u8 *efx_tx_get_copy_buffer(struct efx_tx_queue *tx_queue,
+ struct efx_tx_buffer *buffer)
{
- return tx_queue->insert_count & tx_queue->ptr_mask;
-}
+ unsigned int index = efx_tx_queue_get_insert_index(tx_queue);
+ struct efx_buffer *page_buf =
+ &tx_queue->cb_page[index >> (PAGE_SHIFT - EFX_TX_CB_ORDER)];
+ unsigned int offset =
+ ((index << EFX_TX_CB_ORDER) + NET_IP_ALIGN) & (PAGE_SIZE - 1);
-static inline struct efx_tx_buffer *
-__efx_tx_queue_get_insert_buffer(const struct efx_tx_queue *tx_queue)
-{
- return &tx_queue->buffer[efx_tx_queue_get_insert_index(tx_queue)];
+ if (unlikely(!page_buf->addr) &&
+ efx_nic_alloc_buffer(tx_queue->efx, page_buf, PAGE_SIZE,
+ GFP_ATOMIC))
+ return NULL;
+ buffer->dma_addr = page_buf->dma_addr + offset;
+ buffer->unmap_len = 0;
+ return (u8 *)page_buf->addr + offset;
}
-static inline struct efx_tx_buffer *
-efx_tx_queue_get_insert_buffer(const struct efx_tx_queue *tx_queue)
+u8 *efx_tx_get_copy_buffer_limited(struct efx_tx_queue *tx_queue,
+ struct efx_tx_buffer *buffer, size_t len)
{
- struct efx_tx_buffer *buffer =
- __efx_tx_queue_get_insert_buffer(tx_queue);
-
- EFX_BUG_ON_PARANOID(buffer->len);
- EFX_BUG_ON_PARANOID(buffer->flags);
- EFX_BUG_ON_PARANOID(buffer->unmap_len);
-
- return buffer;
+ if (len > EFX_TX_CB_SIZE)
+ return NULL;
+ return efx_tx_get_copy_buffer(tx_queue, buffer);
}
static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue,
@@ -90,27 +92,6 @@ static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue,
buffer->flags = 0;
}
-static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
- struct sk_buff *skb);
-
-static inline unsigned
-efx_max_tx_len(struct efx_nic *efx, dma_addr_t dma_addr)
-{
- /* Depending on the NIC revision, we can use descriptor
- * lengths up to 8K or 8K-1. However, since PCI Express
- * devices must split read requests at 4K boundaries, there is
- * little benefit from using descriptors that cross those
- * boundaries and we keep things simple by not doing so.
- */
- unsigned len = (~dma_addr & (EFX_PAGE_SIZE - 1)) + 1;
-
- /* Work around hardware bug for unaligned buffers. */
- if (EFX_WORKAROUND_5391(efx) && (dma_addr & 0xf))
- len = min_t(unsigned, len, 512 - (dma_addr & 0xf));
-
- return len;
-}
-
unsigned int efx_tx_max_skb_descs(struct efx_nic *efx)
{
/* Header and payload descriptor for each output segment, plus
@@ -173,6 +154,39 @@ static void efx_tx_maybe_stop_queue(struct efx_tx_queue *txq1)
}
}
+static int efx_enqueue_skb_copy(struct efx_tx_queue *tx_queue,
+ struct sk_buff *skb)
+{
+ unsigned int min_len = tx_queue->tx_min_size;
+ unsigned int copy_len = skb->len;
+ struct efx_tx_buffer *buffer;
+ u8 *copy_buffer;
+ int rc;
+
+ EFX_BUG_ON_PARANOID(copy_len > EFX_TX_CB_SIZE);
+
+ buffer = efx_tx_queue_get_insert_buffer(tx_queue);
+
+ copy_buffer = efx_tx_get_copy_buffer(tx_queue, buffer);
+ if (unlikely(!copy_buffer))
+ return -ENOMEM;
+
+ rc = skb_copy_bits(skb, 0, copy_buffer, copy_len);
+ EFX_WARN_ON_PARANOID(rc);
+ if (unlikely(copy_len < min_len)) {
+ memset(copy_buffer + copy_len, 0, min_len - copy_len);
+ buffer->len = min_len;
+ } else {
+ buffer->len = copy_len;
+ }
+
+ buffer->skb = skb;
+ buffer->flags = EFX_TX_BUF_SKB;
+
+ ++tx_queue->insert_count;
+ return rc;
+}
+
#ifdef EFX_USE_PIO
struct efx_short_copy_buffer {
@@ -267,8 +281,8 @@ static void efx_skb_copy_bits_to_pio(struct efx_nic *efx, struct sk_buff *skb,
EFX_BUG_ON_PARANOID(skb_shinfo(skb)->frag_list);
}
-static struct efx_tx_buffer *
-efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
+static int efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue,
+ struct sk_buff *skb)
{
struct efx_tx_buffer *buffer =
efx_tx_queue_get_insert_buffer(tx_queue);
@@ -292,7 +306,7 @@ efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
efx_flush_copy_buffer(tx_queue->efx, piobuf, &copy_buf);
} else {
/* Pad the write to the size of a cache line.
- * We can do this because we know the skb_shared_info sruct is
+ * We can do this because we know the skb_shared_info struct is
* after the source, and the destination buffer is big enough.
*/
BUILD_BUG_ON(L1_CACHE_BYTES >
@@ -301,6 +315,9 @@ efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
ALIGN(skb->len, L1_CACHE_BYTES) >> 3);
}
+ buffer->skb = skb;
+ buffer->flags = EFX_TX_BUF_SKB | EFX_TX_BUF_OPTION;
+
EFX_POPULATE_QWORD_5(buffer->option,
ESF_DZ_TX_DESC_IS_OPT, 1,
ESF_DZ_TX_OPTION_TYPE, ESE_DZ_TX_OPTION_DESC_PIO,
@@ -308,127 +325,192 @@ efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
ESF_DZ_TX_PIO_BYTE_CNT, skb->len,
ESF_DZ_TX_PIO_BUF_ADDR,
tx_queue->piobuf_offset);
- ++tx_queue->pio_packets;
++tx_queue->insert_count;
- return buffer;
+ return 0;
}
#endif /* EFX_USE_PIO */
-/*
- * Add a socket buffer to a TX queue
- *
- * This maps all fragments of a socket buffer for DMA and adds them to
- * the TX queue. The queue's insert pointer will be incremented by
- * the number of fragments in the socket buffer.
- *
- * If any DMA mapping fails, any mapped fragments will be unmapped,
- * the queue's insert pointer will be restored to its original value.
- *
- * 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.
- * 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)
+static struct efx_tx_buffer *efx_tx_map_chunk(struct efx_tx_queue *tx_queue,
+ dma_addr_t dma_addr,
+ size_t len)
{
- struct efx_nic *efx = tx_queue->efx;
- struct device *dma_dev = &efx->pci_dev->dev;
+ const struct efx_nic_type *nic_type = tx_queue->efx->type;
struct efx_tx_buffer *buffer;
- unsigned int old_insert_count = tx_queue->insert_count;
- skb_frag_t *fragment;
- unsigned int len, unmap_len = 0;
- dma_addr_t dma_addr, unmap_addr = 0;
unsigned int dma_len;
- unsigned short dma_flags;
- int i = 0;
- if (skb_shinfo(skb)->gso_size)
- return efx_enqueue_skb_tso(tx_queue, skb);
+ /* Map the fragment taking account of NIC-dependent DMA limits. */
+ do {
+ buffer = efx_tx_queue_get_insert_buffer(tx_queue);
+ dma_len = nic_type->tx_limit_len(tx_queue, dma_addr, len);
- /* Get size of the initial fragment */
- len = skb_headlen(skb);
+ 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);
- /* Pad if necessary */
- if (EFX_WORKAROUND_15592(efx) && skb->len <= 32) {
- EFX_BUG_ON_PARANOID(skb->data_len);
- len = 32 + 1;
- if (skb_pad(skb, len - skb->len))
- return NETDEV_TX_OK;
- }
+ return buffer;
+}
- /* Consider using PIO for short packets */
-#ifdef EFX_USE_PIO
- if (skb->len <= efx_piobuf_size && !skb->xmit_more &&
- efx_nic_may_tx_pio(tx_queue)) {
- buffer = efx_enqueue_skb_pio(tx_queue, skb);
- dma_flags = EFX_TX_BUF_OPTION;
- goto finish_packet;
- }
-#endif
+/* Map all data from an SKB for DMA and create descriptors on the queue.
+ */
+static int efx_tx_map_data(struct efx_tx_queue *tx_queue, struct sk_buff *skb,
+ unsigned int segment_count)
+{
+ struct efx_nic *efx = tx_queue->efx;
+ struct device *dma_dev = &efx->pci_dev->dev;
+ unsigned int frag_index, nr_frags;
+ dma_addr_t dma_addr, unmap_addr;
+ unsigned short dma_flags;
+ size_t len, unmap_len;
- /* Map for DMA. Use dma_map_single rather than dma_map_page
- * since this is more efficient on machines with sparse
- * memory.
- */
- dma_flags = EFX_TX_BUF_MAP_SINGLE;
- dma_addr = dma_map_single(dma_dev, skb->data, len, PCI_DMA_TODEVICE);
+ nr_frags = skb_shinfo(skb)->nr_frags;
+ frag_index = 0;
- /* Process all fragments */
- while (1) {
- if (unlikely(dma_mapping_error(dma_dev, dma_addr)))
- goto dma_err;
+ /* Map header data. */
+ len = skb_headlen(skb);
+ dma_addr = dma_map_single(dma_dev, skb->data, len, DMA_TO_DEVICE);
+ dma_flags = EFX_TX_BUF_MAP_SINGLE;
+ unmap_len = len;
+ unmap_addr = dma_addr;
- /* Store fields for marking in the per-fragment final
- * descriptor */
- unmap_len = len;
- unmap_addr = dma_addr;
+ if (unlikely(dma_mapping_error(dma_dev, dma_addr)))
+ return -EIO;
- /* Add to TX queue, splitting across DMA boundaries */
- do {
- buffer = efx_tx_queue_get_insert_buffer(tx_queue);
+ if (segment_count) {
+ /* For TSO we need to put the header in to a separate
+ * descriptor. Map this separately if necessary.
+ */
+ size_t header_len = skb_transport_header(skb) - skb->data +
+ (tcp_hdr(skb)->doff << 2u);
+
+ if (header_len != len) {
+ tx_queue->tso_long_headers++;
+ efx_tx_map_chunk(tx_queue, dma_addr, header_len);
+ len -= header_len;
+ dma_addr += header_len;
+ }
+ }
- dma_len = efx_max_tx_len(efx, dma_addr);
- if (likely(dma_len >= len))
- dma_len = len;
+ /* Add descriptors for each fragment. */
+ do {
+ struct efx_tx_buffer *buffer;
+ skb_frag_t *fragment;
- /* 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);
+ buffer = efx_tx_map_chunk(tx_queue, dma_addr, len);
- /* Transfer ownership of the unmapping to the final buffer */
+ /* The final descriptor for a fragment is responsible for
+ * unmapping the whole fragment.
+ */
buffer->flags = EFX_TX_BUF_CONT | dma_flags;
buffer->unmap_len = unmap_len;
buffer->dma_offset = buffer->dma_addr - unmap_addr;
- unmap_len = 0;
- /* Get address and size of next fragment */
- if (i >= skb_shinfo(skb)->nr_frags)
- break;
- fragment = &skb_shinfo(skb)->frags[i];
+ if (frag_index >= nr_frags) {
+ /* Store SKB details with the final buffer for
+ * the completion.
+ */
+ buffer->skb = skb;
+ buffer->flags = EFX_TX_BUF_SKB | dma_flags;
+ return 0;
+ }
+
+ /* Move on to the next fragment. */
+ fragment = &skb_shinfo(skb)->frags[frag_index++];
len = skb_frag_size(fragment);
- i++;
- /* Map for DMA */
+ dma_addr = skb_frag_dma_map(dma_dev, fragment,
+ 0, len, DMA_TO_DEVICE);
dma_flags = 0;
- dma_addr = skb_frag_dma_map(dma_dev, fragment, 0, len,
- DMA_TO_DEVICE);
+ unmap_len = len;
+ unmap_addr = dma_addr;
+
+ if (unlikely(dma_mapping_error(dma_dev, dma_addr)))
+ return -EIO;
+ } while (1);
+}
+
+/* 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;
+
+ /* Work backwards until we hit the original insert pointer value */
+ while (tx_queue->insert_count != tx_queue->write_count) {
+ --tx_queue->insert_count;
+ buffer = __efx_tx_queue_get_insert_buffer(tx_queue);
+ efx_dequeue_buffer(tx_queue, buffer, NULL, NULL);
}
+}
+
+static int efx_tx_tso_sw(struct efx_tx_queue *tx_queue, struct sk_buff *skb,
+ bool *data_mapped)
+{
+ return efx_enqueue_skb_tso(tx_queue, skb, data_mapped);
+}
+
+/*
+ * Add a socket buffer to a TX queue
+ *
+ * This maps all fragments of a socket buffer for DMA and adds them to
+ * the TX queue. The queue's insert pointer will be incremented by
+ * the number of fragments in the socket buffer.
+ *
+ * If any DMA mapping fails, any mapped fragments will be unmapped,
+ * the queue's insert pointer will be restored to its original value.
+ *
+ * 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.
+ * 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)
+{
+ bool data_mapped = false;
+ unsigned int segments;
+ unsigned int skb_len;
- /* Transfer ownership of the skb to the final buffer */
+ skb_len = skb->len;
+ segments = skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 0;
+ if (segments == 1)
+ segments = 0; /* Don't use TSO for a single segment. */
+
+ /* Handle TSO first - it's *possible* (although unlikely) that we might
+ * be passed a packet to segment that's smaller than the copybreak/PIO
+ * size limit.
+ */
+ if (segments) {
+ EFX_BUG_ON_PARANOID(!tx_queue->handle_tso);
+ if (tx_queue->handle_tso(tx_queue, skb, &data_mapped))
+ goto err;
#ifdef EFX_USE_PIO
-finish_packet:
+ } else if (skb_len <= efx_piobuf_size && !skb->xmit_more &&
+ efx_nic_may_tx_pio(tx_queue)) {
+ /* Use PIO for short packets with an empty queue. */
+ if (efx_enqueue_skb_pio(tx_queue, skb))
+ goto err;
+ tx_queue->pio_packets++;
+ data_mapped = true;
#endif
- buffer->skb = skb;
- buffer->flags = EFX_TX_BUF_SKB | dma_flags;
+ } else if (skb_len < tx_queue->tx_min_size ||
+ (skb->data_len && skb_len <= EFX_TX_CB_SIZE)) {
+ /* Pad short packets or coalesce short fragmented packets. */
+ if (efx_enqueue_skb_copy(tx_queue, skb))
+ goto err;
+ tx_queue->cb_packets++;
+ data_mapped = true;
+ }
- netdev_tx_sent_queue(tx_queue->core_txq, skb->len);
+ /* Map for DMA and create descriptors if we haven't done so already. */
+ if (!data_mapped && (efx_tx_map_data(tx_queue, skb, segments)))
+ goto err;
- efx_tx_maybe_stop_queue(tx_queue);
+ /* Update BQL */
+ netdev_tx_sent_queue(tx_queue->core_txq, skb_len);
/* Pass off to hardware */
if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {
@@ -446,37 +528,22 @@ finish_packet:
tx_queue->xmit_more_available = skb->xmit_more;
}
- tx_queue->tx_packets++;
+ if (segments) {
+ tx_queue->tso_bursts++;
+ tx_queue->tso_packets += segments;
+ tx_queue->tx_packets += segments;
+ } else {
+ tx_queue->tx_packets++;
+ }
+
+ efx_tx_maybe_stop_queue(tx_queue);
return NETDEV_TX_OK;
- dma_err:
- netif_err(efx, tx_err, efx->net_dev,
- " TX queue %d could not map skb with %d bytes %d "
- "fragments for DMA\n", tx_queue->queue, skb->len,
- skb_shinfo(skb)->nr_frags + 1);
- /* Mark the packet as transmitted, and free the SKB ourselves */
+err:
+ efx_enqueue_unwind(tx_queue);
dev_kfree_skb_any(skb);
-
- /* Work backwards until we hit the original insert pointer value */
- while (tx_queue->insert_count != old_insert_count) {
- unsigned int pkts_compl = 0, bytes_compl = 0;
- --tx_queue->insert_count;
- buffer = __efx_tx_queue_get_insert_buffer(tx_queue);
- efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl);
- }
-
- /* Free the fragment we were mid-way through pushing */
- if (unmap_len) {
- if (dma_flags & EFX_TX_BUF_MAP_SINGLE)
- dma_unmap_single(dma_dev, unmap_addr, unmap_len,
- DMA_TO_DEVICE);
- else
- dma_unmap_page(dma_dev, unmap_addr, unmap_len,
- DMA_TO_DEVICE);
- }
-
return NETDEV_TX_OK;
}
@@ -667,19 +734,9 @@ 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)
+static unsigned int efx_tx_cb_page_count(struct efx_tx_queue *tx_queue)
{
- return DIV_ROUND_UP(tx_queue->ptr_mask + 1, 2 * TSOH_PER_PAGE);
+ return DIV_ROUND_UP(tx_queue->ptr_mask + 1, PAGE_SIZE >> EFX_TX_CB_ORDER);
}
int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
@@ -703,14 +760,11 @@ int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
if (!tx_queue->buffer)
return -ENOMEM;
- 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;
- }
+ tx_queue->cb_page = kcalloc(efx_tx_cb_page_count(tx_queue),
+ sizeof(tx_queue->cb_page[0]), GFP_KERNEL);
+ if (!tx_queue->cb_page) {
+ rc = -ENOMEM;
+ goto fail1;
}
/* Allocate hardware ring */
@@ -721,8 +775,8 @@ int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
return 0;
fail2:
- kfree(tx_queue->tsoh_page);
- tx_queue->tsoh_page = NULL;
+ kfree(tx_queue->cb_page);
+ tx_queue->cb_page = NULL;
fail1:
kfree(tx_queue->buffer);
tx_queue->buffer = NULL;
@@ -731,7 +785,9 @@ fail1:
void efx_init_tx_queue(struct efx_tx_queue *tx_queue)
{
- netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev,
+ struct efx_nic *efx = tx_queue->efx;
+
+ netif_dbg(efx, drv, efx->net_dev,
"initialising TX queue %d\n", tx_queue->queue);
tx_queue->insert_count = 0;
@@ -742,6 +798,14 @@ void efx_init_tx_queue(struct efx_tx_queue *tx_queue)
tx_queue->empty_read_count = 0 | EFX_EMPTY_COUNT_VALID;
tx_queue->xmit_more_available = false;
+ /* Set up default function pointers. These may get replaced by
+ * efx_nic_init_tx() based off NIC/queue capabilities.
+ */
+ tx_queue->handle_tso = efx_tx_tso_sw;
+
+ /* Some older hardware requires Tx writes larger than 32. */
+ tx_queue->tx_min_size = EFX_WORKAROUND_15592(efx) ? 33 : 0;
+
/* Set up TX descriptor ring */
efx_nic_init_tx(tx_queue);
@@ -781,589 +845,14 @@ 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++)
+ if (tx_queue->cb_page) {
+ for (i = 0; i < efx_tx_cb_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;
+ &tx_queue->cb_page[i]);
+ kfree(tx_queue->cb_page);
+ tx_queue->cb_page = NULL;
}
kfree(tx_queue->buffer);
tx_queue->buffer = NULL;
}
-
-
-/* Efx TCP segmentation acceleration.
- *
- * Why? Because by doing it here in the driver we can go significantly
- * faster than the GSO.
- *
- * Requires TX checksum offload support.
- */
-
-#define PTR_DIFF(p1, p2) ((u8 *)(p1) - (u8 *)(p2))
-
-/**
- * struct tso_state - TSO state for an SKB
- * @out_len: Remaining length in current segment
- * @seqnum: Current sequence number
- * @ipv4_id: Current IPv4 ID, host endian
- * @packet_space: Remaining space in current packet
- * @dma_addr: DMA address of current position
- * @in_len: Remaining length in current SKB fragment
- * @unmap_len: Length of SKB fragment
- * @unmap_addr: DMA address of SKB fragment
- * @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
- * @ip_base_len: IPv4 tot_len or IPv6 payload_len, before TCP payload
- * @header_dma_addr: Header DMA address, when using option descriptors
- * @header_unmap_len: Header DMA mapped length, or 0 if not using option
- * descriptors
- *
- * The state used during segmentation. It is put into this data structure
- * just to make it easy to pass into inline functions.
- */
-struct tso_state {
- /* Output position */
- unsigned out_len;
- unsigned seqnum;
- u16 ipv4_id;
- unsigned packet_space;
-
- /* Input position */
- dma_addr_t dma_addr;
- unsigned in_len;
- unsigned unmap_len;
- dma_addr_t unmap_addr;
- unsigned short dma_flags;
-
- __be16 protocol;
- unsigned int ip_off;
- unsigned int tcp_off;
- unsigned header_len;
- unsigned int ip_base_len;
- dma_addr_t header_dma_addr;
- unsigned int header_unmap_len;
-};
-
-
-/*
- * Verify that our various assumptions about sk_buffs and the conditions
- * under which TSO will be attempted hold true. Return the protocol number.
- */
-static __be16 efx_tso_check_protocol(struct sk_buff *skb)
-{
- __be16 protocol = skb->protocol;
-
- EFX_BUG_ON_PARANOID(((struct ethhdr *)skb->data)->h_proto !=
- protocol);
- if (protocol == htons(ETH_P_8021Q)) {
- struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
- protocol = veh->h_vlan_encapsulated_proto;
- }
-
- if (protocol == htons(ETH_P_IP)) {
- EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP);
- } else {
- EFX_BUG_ON_PARANOID(protocol != htons(ETH_P_IPV6));
- EFX_BUG_ON_PARANOID(ipv6_hdr(skb)->nexthdr != NEXTHDR_TCP);
- }
- EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb), skb->data)
- + (tcp_hdr(skb)->doff << 2u)) >
- skb_headlen(skb));
-
- return protocol;
-}
-
-static u8 *efx_tsoh_get_buffer(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer, unsigned int len)
-{
- u8 *result;
-
- EFX_BUG_ON_PARANOID(buffer->len);
- EFX_BUG_ON_PARANOID(buffer->flags);
- EFX_BUG_ON_PARANOID(buffer->unmap_len);
-
- if (likely(len <= TSOH_STD_SIZE - NET_IP_ALIGN)) {
- 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) + NET_IP_ALIGN;
-
- if (unlikely(!page_buf->addr) &&
- efx_nic_alloc_buffer(tx_queue->efx, page_buf, PAGE_SIZE,
- GFP_ATOMIC))
- 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++;
-
- buffer->heap_buf = kmalloc(NET_IP_ALIGN + len, GFP_ATOMIC);
- if (unlikely(!buffer->heap_buf))
- return NULL;
- result = (u8 *)buffer->heap_buf + NET_IP_ALIGN;
- buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_HEAP;
- }
-
- buffer->len = len;
-
- return result;
-}
-
-/**
- * efx_tx_queue_insert - push descriptors onto the TX queue
- * @tx_queue: Efx TX queue
- * @dma_addr: DMA address of fragment
- * @len: Length of fragment
- * @final_buffer: The final buffer inserted into the queue
- *
- * Push descriptors onto the TX queue.
- */
-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;
-
- EFX_BUG_ON_PARANOID(len <= 0);
-
- while (1) {
- buffer = efx_tx_queue_get_insert_buffer(tx_queue);
- ++tx_queue->insert_count;
-
- EFX_BUG_ON_PARANOID(tx_queue->insert_count -
- tx_queue->read_count >=
- efx->txq_entries);
-
- buffer->dma_addr = dma_addr;
-
- dma_len = efx_max_tx_len(efx, dma_addr);
-
- /* If there is enough space to send then do so */
- if (dma_len >= len)
- break;
-
- buffer->len = dma_len;
- buffer->flags = EFX_TX_BUF_CONT;
- dma_addr += dma_len;
- len -= dma_len;
- }
-
- EFX_BUG_ON_PARANOID(!len);
- buffer->len = len;
- *final_buffer = buffer;
-}
-
-
-/*
- * Put a TSO header into the TX queue.
- *
- * This is special-cased because we know that it is small enough to fit in
- * 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 int efx_tso_put_header(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer, u8 *header)
-{
- 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->dma_offset = 0;
- buffer->flags |= EFX_TX_BUF_MAP_SINGLE;
- }
-
- ++tx_queue->insert_count;
- return 0;
-}
-
-
-/* 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,
- unsigned int insert_count)
-{
- struct efx_tx_buffer *buffer;
-
- /* Work backwards until we hit the original insert pointer value */
- while (tx_queue->insert_count != insert_count) {
- --tx_queue->insert_count;
- buffer = __efx_tx_queue_get_insert_buffer(tx_queue);
- efx_dequeue_buffer(tx_queue, buffer, NULL, NULL);
- }
-}
-
-
-/* Parse the SKB header and initialise state. */
-static int tso_start(struct tso_state *st, struct efx_nic *efx,
- struct efx_tx_queue *tx_queue,
- const struct sk_buff *skb)
-{
- struct device *dma_dev = &efx->pci_dev->dev;
- unsigned int header_len, in_len;
- bool use_opt_desc = false;
- dma_addr_t dma_addr;
-
- if (tx_queue->tso_version == 1)
- use_opt_desc = true;
-
- st->ip_off = skb_network_header(skb) - skb->data;
- st->tcp_off = skb_transport_header(skb) - skb->data;
- header_len = st->tcp_off + (tcp_hdr(skb)->doff << 2u);
- in_len = skb_headlen(skb) - header_len;
- st->header_len = header_len;
- st->in_len = in_len;
- 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 {
- 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);
- EFX_BUG_ON_PARANOID(tcp_hdr(skb)->syn);
- EFX_BUG_ON_PARANOID(tcp_hdr(skb)->rst);
-
- st->out_len = skb->len - header_len;
-
- if (!use_opt_desc) {
- st->header_unmap_len = 0;
-
- if (likely(in_len == 0)) {
- st->dma_flags = 0;
- st->unmap_len = 0;
- return 0;
- }
-
- dma_addr = dma_map_single(dma_dev, skb->data + header_len,
- in_len, DMA_TO_DEVICE);
- st->dma_flags = EFX_TX_BUF_MAP_SINGLE;
- st->dma_addr = dma_addr;
- st->unmap_addr = dma_addr;
- st->unmap_len = in_len;
- } else {
- dma_addr = dma_map_single(dma_dev, skb->data,
- skb_headlen(skb), DMA_TO_DEVICE);
- st->header_dma_addr = dma_addr;
- st->header_unmap_len = skb_headlen(skb);
- st->dma_flags = 0;
- st->dma_addr = dma_addr + header_len;
- st->unmap_len = 0;
- }
-
- return unlikely(dma_mapping_error(dma_dev, dma_addr)) ? -ENOMEM : 0;
-}
-
-static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
- skb_frag_t *frag)
-{
- 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->dma_flags = 0;
- st->unmap_len = skb_frag_size(frag);
- st->in_len = skb_frag_size(frag);
- st->dma_addr = st->unmap_addr;
- return 0;
- }
- return -ENOMEM;
-}
-
-
-/**
- * tso_fill_packet_with_fragment - form descriptors for the current fragment
- * @tx_queue: Efx TX queue
- * @skb: Socket buffer
- * @st: TSO state
- *
- * Form descriptors for the current fragment, until we reach the end
- * of fragment or end-of-packet.
- */
-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;
-
- if (st->in_len == 0)
- return;
- if (st->packet_space == 0)
- return;
-
- EFX_BUG_ON_PARANOID(st->in_len <= 0);
- EFX_BUG_ON_PARANOID(st->packet_space <= 0);
-
- n = min(st->in_len, st->packet_space);
-
- st->packet_space -= n;
- st->out_len -= n;
- st->in_len -= n;
-
- efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer);
-
- 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->dma_offset = buffer->unmap_len - buffer->len;
- buffer->flags |= st->dma_flags;
- st->unmap_len = 0;
- }
-
- st->dma_addr += n;
-}
-
-
-/**
- * tso_start_new_packet - generate a new header and prepare for the new packet
- * @tx_queue: Efx TX queue
- * @skb: Socket buffer
- * @st: TSO state
- *
- * Generate a new header and prepare for the new packet. Return 0 on
- * 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_tx_buffer *buffer =
- efx_tx_queue_get_insert_buffer(tx_queue);
- bool is_last = st->out_len <= skb_shinfo(skb)->gso_size;
- u8 tcp_flags_clear;
-
- if (!is_last) {
- st->packet_space = skb_shinfo(skb)->gso_size;
- tcp_flags_clear = 0x09; /* mask out FIN and PSH */
- } else {
- st->packet_space = st->out_len;
- tcp_flags_clear = 0x00;
- }
-
- if (!st->header_unmap_len) {
- /* Allocate and insert a DMA-mapped header buffer. */
- struct tcphdr *tsoh_th;
- unsigned ip_length;
- u8 *header;
- int rc;
-
- header = efx_tsoh_get_buffer(tx_queue, buffer, st->header_len);
- if (!header)
- return -ENOMEM;
-
- tsoh_th = (struct tcphdr *)(header + st->tcp_off);
-
- /* Copy and update the headers. */
- memcpy(header, skb->data, st->header_len);
-
- tsoh_th->seq = htonl(st->seqnum);
- ((u8 *)tsoh_th)[13] &= ~tcp_flags_clear;
-
- ip_length = st->ip_base_len + st->packet_space;
-
- if (st->protocol == htons(ETH_P_IP)) {
- struct iphdr *tsoh_iph =
- (struct iphdr *)(header + st->ip_off);
-
- tsoh_iph->tot_len = htons(ip_length);
- tsoh_iph->id = htons(st->ipv4_id);
- } else {
- struct ipv6hdr *tsoh_iph =
- (struct ipv6hdr *)(header + st->ip_off);
-
- tsoh_iph->payload_len = htons(ip_length);
- }
-
- rc = efx_tso_put_header(tx_queue, buffer, header);
- if (unlikely(rc))
- return rc;
- } else {
- /* Send the original headers with a TSO option descriptor
- * in front
- */
- u8 tcp_flags = ((u8 *)tcp_hdr(skb))[13] & ~tcp_flags_clear;
-
- buffer->flags = EFX_TX_BUF_OPTION;
- buffer->len = 0;
- buffer->unmap_len = 0;
- EFX_POPULATE_QWORD_5(buffer->option,
- ESF_DZ_TX_DESC_IS_OPT, 1,
- ESF_DZ_TX_OPTION_TYPE,
- ESE_DZ_TX_OPTION_DESC_TSO,
- ESF_DZ_TX_TSO_TCP_FLAGS, tcp_flags,
- ESF_DZ_TX_TSO_IP_ID, st->ipv4_id,
- ESF_DZ_TX_TSO_TCP_SEQNO, st->seqnum);
- ++tx_queue->insert_count;
-
- /* We mapped the headers in tso_start(). Unmap them
- * when the last segment is completed.
- */
- buffer = efx_tx_queue_get_insert_buffer(tx_queue);
- buffer->dma_addr = st->header_dma_addr;
- buffer->len = st->header_len;
- if (is_last) {
- buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_MAP_SINGLE;
- buffer->unmap_len = st->header_unmap_len;
- buffer->dma_offset = 0;
- /* Ensure we only unmap them once in case of a
- * later DMA mapping error and rollback
- */
- st->header_unmap_len = 0;
- } else {
- buffer->flags = EFX_TX_BUF_CONT;
- buffer->unmap_len = 0;
- }
- ++tx_queue->insert_count;
- }
-
- st->seqnum += skb_shinfo(skb)->gso_size;
-
- /* Linux leaves suitable gaps in the IP ID space for us to fill. */
- ++st->ipv4_id;
-
- ++tx_queue->tso_packets;
-
- ++tx_queue->tx_packets;
-
- return 0;
-}
-
-
-/**
- * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer
- * @tx_queue: Efx TX queue
- * @skb: Socket buffer
- *
- * Context: You must hold netif_tx_lock() to call this function.
- *
- * 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.
- */
-static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
- struct sk_buff *skb)
-{
- struct efx_nic *efx = tx_queue->efx;
- unsigned int old_insert_count = tx_queue->insert_count;
- int frag_i, rc;
- struct tso_state state;
-
- /* Find the packet protocol and sanity-check it */
- state.protocol = efx_tso_check_protocol(skb);
-
- rc = tso_start(&state, efx, tx_queue, skb);
- if (rc)
- goto mem_err;
-
- if (likely(state.in_len == 0)) {
- /* Grab the first payload fragment. */
- EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1);
- frag_i = 0;
- rc = tso_get_fragment(&state, efx,
- skb_shinfo(skb)->frags + frag_i);
- if (rc)
- goto mem_err;
- } else {
- /* Payload starts in the header area. */
- frag_i = -1;
- }
-
- if (tso_start_new_packet(tx_queue, skb, &state) < 0)
- goto mem_err;
-
- while (1) {
- tso_fill_packet_with_fragment(tx_queue, skb, &state);
-
- /* Move onto the next fragment? */
- if (state.in_len == 0) {
- if (++frag_i >= skb_shinfo(skb)->nr_frags)
- /* End of payload reached. */
- break;
- rc = tso_get_fragment(&state, efx,
- skb_shinfo(skb)->frags + frag_i);
- if (rc)
- goto mem_err;
- }
-
- /* Start at new packet? */
- if (state.packet_space == 0 &&
- tso_start_new_packet(tx_queue, skb, &state) < 0)
- goto mem_err;
- }
-
- netdev_tx_sent_queue(tx_queue->core_txq, skb->len);
-
- efx_tx_maybe_stop_queue(tx_queue);
-
- /* Pass off to hardware */
- if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {
- struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
-
- /* There could be packets left on the partner queue if those
- * SKBs had skb->xmit_more set. If we do not push those they
- * could be left for a long time and cause a netdev watchdog.
- */
- if (txq2->xmit_more_available)
- efx_nic_push_buffers(txq2);
-
- efx_nic_push_buffers(tx_queue);
- } else {
- tx_queue->xmit_more_available = skb->xmit_more;
- }
-
- tx_queue->tso_bursts++;
- return NETDEV_TX_OK;
-
- mem_err:
- netif_err(efx, tx_err, efx->net_dev,
- "Out of memory for TSO headers, or DMA mapping error\n");
- dev_kfree_skb_any(skb);
-
- /* Free the DMA mapping we were in the process of writing out */
- if (state.unmap_len) {
- 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
- dma_unmap_page(&efx->pci_dev->dev, state.unmap_addr,
- state.unmap_len, DMA_TO_DEVICE);
- }
-
- /* Free the header DMA mapping, if using option descriptors */
- if (state.header_unmap_len)
- dma_unmap_single(&efx->pci_dev->dev, state.header_dma_addr,
- state.header_unmap_len, DMA_TO_DEVICE);
-
- efx_enqueue_unwind(tx_queue, old_insert_count);
- return NETDEV_TX_OK;
-}