// 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 all queues that the net core sees as one */ struct efx_nic *efx = txq1->efx; struct efx_tx_queue *txq2; unsigned int fill_level; fill_level = efx_channel_tx_old_fill_level(txq1->channel); 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(); efx_for_each_channel_tx_queue(txq2, txq1->channel) txq2->old_read_count = READ_ONCE(txq2->read_count); fill_level = efx_channel_tx_old_fill_level(txq1->channel); 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; } /* Decide whether we can use TX PIO, ie. write packet data directly into * a buffer on the device. This can reduce latency at the expense of * throughput, so we only do this if both hardware and software TX rings * are empty, including all queues for the channel. This also ensures that * only one packet at a time can be using the PIO buffer. If the xmit_more * flag is set then we don't use this - there'll be another packet along * shortly and we want to hold off the doorbell. */ static bool efx_tx_may_pio(struct efx_tx_queue *tx_queue) { struct efx_channel *channel = tx_queue->channel; if (!tx_queue->piobuf) return false; EFX_WARN_ON_ONCE_PARANOID(!channel->efx->type->option_descriptors); efx_for_each_channel_tx_queue(tx_queue, channel) if (!efx_nic_tx_is_empty(tx_queue, tx_queue->packet_write_count)) return false; return true; } #endif /* EFX_USE_PIO */ /* Send any pending traffic for a channel. xmit_more is shared across all * queues for a channel, so we must check all of them. */ static void efx_tx_send_pending(struct efx_channel *channel) { struct efx_tx_queue *q; efx_for_each_channel_tx_queue(q, channel) { if (q->xmit_pending) efx_nic_push_buffers(q); } } /* * 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) { switch (tx_queue->tso_version) { case 1: rc = efx_enqueue_skb_tso(tx_queue, skb, &data_mapped); break; case 2: rc = efx_ef10_tx_tso_desc(tx_queue, skb, &data_mapped); break; case 0: /* No TSO on this queue, SW fallback needed */ default: rc = -EINVAL; break; } 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_tx_may_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); tx_queue->xmit_pending = true; /* Pass off to hardware */ if (__netdev_tx_sent_queue(tx_queue->core_txq, skb_len, xmit_more)) efx_tx_send_pending(tx_queue->channel); 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) efx_tx_send_pending(tx_queue->channel); return NETDEV_TX_OK; } /* 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 = 0; if (unlikely(n && !xdpfs)) return -EINVAL; if (unlikely(!n)) return 0; cpu = raw_smp_processor_id(); if (unlikely(cpu >= efx->xdp_tx_queue_count)) return -EINVAL; tx_queue = efx->xdp_tx_queues[cpu]; if (unlikely(!tx_queue)) return -EINVAL; if (efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_DEDICATED) HARD_TX_LOCK(efx->net_dev, tx_queue->core_txq, cpu); /* If we're borrowing net stack queues we have to handle stop-restart * or we might block the queue and it will be considered as frozen */ if (efx->xdp_txq_queues_mode == EFX_XDP_TX_QUEUES_BORROWED) { if (netif_tx_queue_stopped(tx_queue->core_txq)) goto unlock; efx_tx_maybe_stop_queue(tx_queue); } /* 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); unlock: if (efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_DEDICATED) HARD_TX_UNLOCK(efx->net_dev, tx_queue->core_txq); return i == 0 ? -EIO : i; } /* Initiate a packet transmission. We use one channel per CPU * (sharing when we have more CPUs than channels). * * Context: non-blocking. * Should always return NETDEV_TX_OK and consume 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)); index = skb_get_queue_mapping(skb); type = efx_tx_csum_type_skb(skb); if (index >= efx->n_tx_channels) { index -= efx->n_tx_channels; type |= EFX_TXQ_TYPE_HIGHPRI; } /* PTP "event" packet */ if (unlikely(efx_xmit_with_hwtstamp(skb)) && unlikely(efx_ptp_is_ptp_tx(efx, skb))) { /* There may be existing transmits on the channel that are * waiting for this packet to trigger the doorbell write. * We need to send the packets at this point. */ efx_tx_send_pending(efx_get_tx_channel(efx, index)); return efx_ptp_tx(efx, skb); } tx_queue = efx_get_tx_queue(efx, index, type); if (WARN_ON_ONCE(!tx_queue)) { /* We don't have a TXQ of the right type. * This should never happen, as we don't advertise offload * features unless we can support them. */ 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 (!netdev_xmit_more()) efx_tx_send_pending(tx_queue->channel); return NETDEV_TX_OK; } 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->channel->channel + ((tx_queue->type & 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; unsigned tc, num_tc; if (type != TC_SETUP_QDISC_MQPRIO) return -EOPNOTSUPP; /* Only Siena supported highpri queues */ if (efx_nic_rev(efx) > EFX_REV_SIENA_A0) 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; } net_dev->num_tc = num_tc; return netif_set_real_num_tx_queues(net_dev, max_t(int, num_tc, 1) * efx->n_tx_channels); }