/drivers/net/ethernet/sfc/tx.c
http://github.com/mirrors/linux · C · 651 lines · 424 code · 110 blank · 117 comment · 72 complexity · 087b5a895405a3e4e5111b77c0584c19 MD5 · raw file
- // SPDX-License-Identifier: GPL-2.0-only
- /****************************************************************************
- * Driver for Solarflare network controllers and boards
- * Copyright 2005-2006 Fen Systems Ltd.
- * Copyright 2005-2013 Solarflare Communications Inc.
- */
- #include <linux/pci.h>
- #include <linux/tcp.h>
- #include <linux/ip.h>
- #include <linux/in.h>
- #include <linux/ipv6.h>
- #include <linux/slab.h>
- #include <net/ipv6.h>
- #include <linux/if_ether.h>
- #include <linux/highmem.h>
- #include <linux/cache.h>
- #include "net_driver.h"
- #include "efx.h"
- #include "io.h"
- #include "nic.h"
- #include "tx.h"
- #include "tx_common.h"
- #include "workarounds.h"
- #include "ef10_regs.h"
- #ifdef EFX_USE_PIO
- #define EFX_PIOBUF_SIZE_DEF ALIGN(256, L1_CACHE_BYTES)
- unsigned int efx_piobuf_size __read_mostly = EFX_PIOBUF_SIZE_DEF;
- #endif /* EFX_USE_PIO */
- static inline u8 *efx_tx_get_copy_buffer(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer)
- {
- 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);
- 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;
- }
- u8 *efx_tx_get_copy_buffer_limited(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer, size_t len)
- {
- if (len > EFX_TX_CB_SIZE)
- return NULL;
- return efx_tx_get_copy_buffer(tx_queue, buffer);
- }
- 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 = READ_ONCE(txq1->read_count);
- txq2->old_read_count = READ_ONCE(txq2->read_count);
- fill_level = max(txq1->insert_count - txq1->old_read_count,
- txq2->insert_count - txq2->old_read_count);
- EFX_WARN_ON_ONCE_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);
- }
- }
- static int efx_enqueue_skb_copy(struct efx_tx_queue *tx_queue,
- struct sk_buff *skb)
- {
- unsigned int copy_len = skb->len;
- struct efx_tx_buffer *buffer;
- u8 *copy_buffer;
- int rc;
- EFX_WARN_ON_ONCE_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);
- 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 {
- int used;
- u8 buf[L1_CACHE_BYTES];
- };
- /* Copy to PIO, respecting that writes to PIO buffers must be dword aligned.
- * Advances piobuf pointer. Leaves additional data in the copy buffer.
- */
- static void efx_memcpy_toio_aligned(struct efx_nic *efx, u8 __iomem **piobuf,
- u8 *data, int len,
- struct efx_short_copy_buffer *copy_buf)
- {
- int block_len = len & ~(sizeof(copy_buf->buf) - 1);
- __iowrite64_copy(*piobuf, data, block_len >> 3);
- *piobuf += block_len;
- len -= block_len;
- if (len) {
- data += block_len;
- BUG_ON(copy_buf->used);
- BUG_ON(len > sizeof(copy_buf->buf));
- memcpy(copy_buf->buf, data, len);
- copy_buf->used = len;
- }
- }
- /* Copy to PIO, respecting dword alignment, popping data from copy buffer first.
- * Advances piobuf pointer. Leaves additional data in the copy buffer.
- */
- static void efx_memcpy_toio_aligned_cb(struct efx_nic *efx, u8 __iomem **piobuf,
- u8 *data, int len,
- struct efx_short_copy_buffer *copy_buf)
- {
- if (copy_buf->used) {
- /* if the copy buffer is partially full, fill it up and write */
- int copy_to_buf =
- min_t(int, sizeof(copy_buf->buf) - copy_buf->used, len);
- memcpy(copy_buf->buf + copy_buf->used, data, copy_to_buf);
- copy_buf->used += copy_to_buf;
- /* if we didn't fill it up then we're done for now */
- if (copy_buf->used < sizeof(copy_buf->buf))
- return;
- __iowrite64_copy(*piobuf, copy_buf->buf,
- sizeof(copy_buf->buf) >> 3);
- *piobuf += sizeof(copy_buf->buf);
- data += copy_to_buf;
- len -= copy_to_buf;
- copy_buf->used = 0;
- }
- efx_memcpy_toio_aligned(efx, piobuf, data, len, copy_buf);
- }
- static void efx_flush_copy_buffer(struct efx_nic *efx, u8 __iomem *piobuf,
- struct efx_short_copy_buffer *copy_buf)
- {
- /* if there's anything in it, write the whole buffer, including junk */
- if (copy_buf->used)
- __iowrite64_copy(piobuf, copy_buf->buf,
- sizeof(copy_buf->buf) >> 3);
- }
- /* Traverse skb structure and copy fragments in to PIO buffer.
- * Advances piobuf pointer.
- */
- static void efx_skb_copy_bits_to_pio(struct efx_nic *efx, struct sk_buff *skb,
- u8 __iomem **piobuf,
- struct efx_short_copy_buffer *copy_buf)
- {
- int i;
- efx_memcpy_toio_aligned(efx, piobuf, skb->data, skb_headlen(skb),
- copy_buf);
- for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) {
- skb_frag_t *f = &skb_shinfo(skb)->frags[i];
- u8 *vaddr;
- vaddr = kmap_atomic(skb_frag_page(f));
- efx_memcpy_toio_aligned_cb(efx, piobuf, vaddr + skb_frag_off(f),
- skb_frag_size(f), copy_buf);
- kunmap_atomic(vaddr);
- }
- EFX_WARN_ON_ONCE_PARANOID(skb_shinfo(skb)->frag_list);
- }
- 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);
- u8 __iomem *piobuf = tx_queue->piobuf;
- /* Copy to PIO buffer. Ensure the writes are padded to the end
- * of a cache line, as this is required for write-combining to be
- * effective on at least x86.
- */
- if (skb_shinfo(skb)->nr_frags) {
- /* The size of the copy buffer will ensure all writes
- * are the size of a cache line.
- */
- struct efx_short_copy_buffer copy_buf;
- copy_buf.used = 0;
- efx_skb_copy_bits_to_pio(tx_queue->efx, skb,
- &piobuf, ©_buf);
- efx_flush_copy_buffer(tx_queue->efx, piobuf, ©_buf);
- } else {
- /* Pad the write to the size of a cache line.
- * 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 >
- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
- __iowrite64_copy(tx_queue->piobuf, skb->data,
- 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,
- ESF_DZ_TX_PIO_CONT, 0,
- ESF_DZ_TX_PIO_BYTE_CNT, skb->len,
- ESF_DZ_TX_PIO_BUF_ADDR,
- tx_queue->piobuf_offset);
- ++tx_queue->insert_count;
- return 0;
- }
- #endif /* EFX_USE_PIO */
- /*
- * Fallback to software TSO.
- *
- * This is used if we are unable to send a GSO packet through hardware TSO.
- * This should only ever happen due to per-queue restrictions - unsupported
- * packets should first be filtered by the feature flags.
- *
- * Returns 0 on success, error code otherwise.
- */
- static int efx_tx_tso_fallback(struct efx_tx_queue *tx_queue,
- struct sk_buff *skb)
- {
- struct sk_buff *segments, *next;
- segments = skb_gso_segment(skb, 0);
- if (IS_ERR(segments))
- return PTR_ERR(segments);
- dev_consume_skb_any(skb);
- skb_list_walk_safe(segments, skb, next) {
- skb_mark_not_on_list(skb);
- efx_enqueue_skb(tx_queue, skb);
- }
- return 0;
- }
- /*
- * 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)
- {
- unsigned int old_insert_count = tx_queue->insert_count;
- bool xmit_more = netdev_xmit_more();
- bool data_mapped = false;
- unsigned int segments;
- unsigned int skb_len;
- int rc;
- 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_WARN_ON_ONCE_PARANOID(!tx_queue->handle_tso);
- rc = tx_queue->handle_tso(tx_queue, skb, &data_mapped);
- if (rc == -EINVAL) {
- rc = efx_tx_tso_fallback(tx_queue, skb);
- tx_queue->tso_fallbacks++;
- if (rc == 0)
- return 0;
- }
- if (rc)
- goto err;
- #ifdef EFX_USE_PIO
- } else if (skb_len <= efx_piobuf_size && !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
- } else if (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;
- }
- /* 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);
- /* Pass off to hardware */
- if (__netdev_tx_sent_queue(tx_queue->core_txq, skb_len, xmit_more)) {
- struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
- /* There could be packets left on the partner queue if
- * xmit_more was 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 = xmit_more;
- }
- if (segments) {
- tx_queue->tso_bursts++;
- tx_queue->tso_packets += segments;
- tx_queue->tx_packets += segments;
- } else {
- tx_queue->tx_packets++;
- }
- return NETDEV_TX_OK;
- err:
- efx_enqueue_unwind(tx_queue, old_insert_count);
- dev_kfree_skb_any(skb);
- /* If we're not expecting another transmit and we had something to push
- * on this queue or a partner queue then we need to push here to get the
- * previous packets out.
- */
- if (!xmit_more) {
- struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
- if (txq2->xmit_more_available)
- efx_nic_push_buffers(txq2);
- efx_nic_push_buffers(tx_queue);
- }
- return NETDEV_TX_OK;
- }
- static void efx_xdp_return_frames(int n, struct xdp_frame **xdpfs)
- {
- int i;
- for (i = 0; i < n; i++)
- xdp_return_frame_rx_napi(xdpfs[i]);
- }
- /* Transmit a packet from an XDP buffer
- *
- * Returns number of packets sent on success, error code otherwise.
- * Runs in NAPI context, either in our poll (for XDP TX) or a different NIC
- * (for XDP redirect).
- */
- int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs,
- bool flush)
- {
- struct efx_tx_buffer *tx_buffer;
- struct efx_tx_queue *tx_queue;
- struct xdp_frame *xdpf;
- dma_addr_t dma_addr;
- unsigned int len;
- int space;
- int cpu;
- int i;
- cpu = raw_smp_processor_id();
- if (!efx->xdp_tx_queue_count ||
- unlikely(cpu >= efx->xdp_tx_queue_count))
- return -EINVAL;
- tx_queue = efx->xdp_tx_queues[cpu];
- if (unlikely(!tx_queue))
- return -EINVAL;
- if (unlikely(n && !xdpfs))
- return -EINVAL;
- if (!n)
- return 0;
- /* Check for available space. We should never need multiple
- * descriptors per frame.
- */
- space = efx->txq_entries +
- tx_queue->read_count - tx_queue->insert_count;
- for (i = 0; i < n; i++) {
- xdpf = xdpfs[i];
- if (i >= space)
- break;
- /* We'll want a descriptor for this tx. */
- prefetchw(__efx_tx_queue_get_insert_buffer(tx_queue));
- len = xdpf->len;
- /* Map for DMA. */
- dma_addr = dma_map_single(&efx->pci_dev->dev,
- xdpf->data, len,
- DMA_TO_DEVICE);
- if (dma_mapping_error(&efx->pci_dev->dev, dma_addr))
- break;
- /* Create descriptor and set up for unmapping DMA. */
- tx_buffer = efx_tx_map_chunk(tx_queue, dma_addr, len);
- tx_buffer->xdpf = xdpf;
- tx_buffer->flags = EFX_TX_BUF_XDP |
- EFX_TX_BUF_MAP_SINGLE;
- tx_buffer->dma_offset = 0;
- tx_buffer->unmap_len = len;
- tx_queue->tx_packets++;
- }
- /* Pass mapped frames to hardware. */
- if (flush && i > 0)
- efx_nic_push_buffers(tx_queue);
- if (i == 0)
- return -EIO;
- efx_xdp_return_frames(n - i, xdpfs + i);
- return i;
- }
- /* Initiate a packet transmission. We use one channel per CPU
- * (sharing when we have more CPUs than channels). On Falcon, the TX
- * completion events will be directed back to the CPU that transmitted
- * the packet, which should be cache-efficient.
- *
- * Context: non-blocking.
- * Note that returning anything other than NETDEV_TX_OK will cause the
- * OS to free the skb.
- */
- netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb,
- struct net_device *net_dev)
- {
- struct efx_nic *efx = netdev_priv(net_dev);
- struct efx_tx_queue *tx_queue;
- unsigned index, type;
- EFX_WARN_ON_PARANOID(!netif_device_present(net_dev));
- /* PTP "event" packet */
- if (unlikely(efx_xmit_with_hwtstamp(skb)) &&
- unlikely(efx_ptp_is_ptp_tx(efx, skb))) {
- return efx_ptp_tx(efx, skb);
- }
- index = skb_get_queue_mapping(skb);
- type = skb->ip_summed == CHECKSUM_PARTIAL ? EFX_TXQ_TYPE_OFFLOAD : 0;
- if (index >= efx->n_tx_channels) {
- index -= efx->n_tx_channels;
- type |= EFX_TXQ_TYPE_HIGHPRI;
- }
- tx_queue = efx_get_tx_queue(efx, index, type);
- return efx_enqueue_skb(tx_queue, skb);
- }
- void efx_xmit_done_single(struct efx_tx_queue *tx_queue)
- {
- unsigned int pkts_compl = 0, bytes_compl = 0;
- unsigned int read_ptr;
- bool finished = false;
- read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
- while (!finished) {
- struct efx_tx_buffer *buffer = &tx_queue->buffer[read_ptr];
- if (!efx_tx_buffer_in_use(buffer)) {
- struct efx_nic *efx = tx_queue->efx;
- netif_err(efx, hw, efx->net_dev,
- "TX queue %d spurious single TX completion\n",
- tx_queue->queue);
- efx_schedule_reset(efx, RESET_TYPE_TX_SKIP);
- return;
- }
- /* Need to check the flag before dequeueing. */
- if (buffer->flags & EFX_TX_BUF_SKB)
- finished = true;
- efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl);
- ++tx_queue->read_count;
- read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
- }
- tx_queue->pkts_compl += pkts_compl;
- tx_queue->bytes_compl += bytes_compl;
- EFX_WARN_ON_PARANOID(pkts_compl != 1);
- efx_xmit_done_check_empty(tx_queue);
- }
- void efx_init_tx_queue_core_txq(struct efx_tx_queue *tx_queue)
- {
- struct efx_nic *efx = tx_queue->efx;
- /* Must be inverse of queue lookup in efx_hard_start_xmit() */
- tx_queue->core_txq =
- netdev_get_tx_queue(efx->net_dev,
- tx_queue->queue / EFX_TXQ_TYPES +
- ((tx_queue->queue & EFX_TXQ_TYPE_HIGHPRI) ?
- efx->n_tx_channels : 0));
- }
- int efx_setup_tc(struct net_device *net_dev, enum tc_setup_type type,
- void *type_data)
- {
- struct efx_nic *efx = netdev_priv(net_dev);
- struct tc_mqprio_qopt *mqprio = type_data;
- struct efx_channel *channel;
- struct efx_tx_queue *tx_queue;
- unsigned tc, num_tc;
- int rc;
- if (type != TC_SETUP_QDISC_MQPRIO)
- return -EOPNOTSUPP;
- num_tc = mqprio->num_tc;
- if (num_tc > EFX_MAX_TX_TC)
- return -EINVAL;
- mqprio->hw = TC_MQPRIO_HW_OFFLOAD_TCS;
- if (num_tc == net_dev->num_tc)
- return 0;
- for (tc = 0; tc < num_tc; tc++) {
- net_dev->tc_to_txq[tc].offset = tc * efx->n_tx_channels;
- net_dev->tc_to_txq[tc].count = efx->n_tx_channels;
- }
- if (num_tc > net_dev->num_tc) {
- /* Initialise high-priority queues as necessary */
- efx_for_each_channel(channel, efx) {
- efx_for_each_possible_channel_tx_queue(tx_queue,
- channel) {
- if (!(tx_queue->queue & EFX_TXQ_TYPE_HIGHPRI))
- continue;
- if (!tx_queue->buffer) {
- rc = efx_probe_tx_queue(tx_queue);
- if (rc)
- return rc;
- }
- if (!tx_queue->initialised)
- efx_init_tx_queue(tx_queue);
- efx_init_tx_queue_core_txq(tx_queue);
- }
- }
- } else {
- /* Reduce number of classes before number of queues */
- net_dev->num_tc = num_tc;
- }
- rc = netif_set_real_num_tx_queues(net_dev,
- max_t(int, num_tc, 1) *
- efx->n_tx_channels);
- if (rc)
- return rc;
- /* Do not destroy high-priority queues when they become
- * unused. We would have to flush them first, and it is
- * fairly difficult to flush a subset of TX queues. Leave
- * it to efx_fini_channels().
- */
- net_dev->num_tc = num_tc;
- return 0;
- }