// 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 #include #include #include #include #include #include #include #include #include #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 = segments; skb_list_walk_safe(skb, 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_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; }