diff options
Diffstat (limited to 'drivers/net/ethernet/sfc/tx_common.c')
| -rw-r--r-- | drivers/net/ethernet/sfc/tx_common.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/drivers/net/ethernet/sfc/tx_common.c b/drivers/net/ethernet/sfc/tx_common.c new file mode 100644 index 000000000000..b1571e9789d0 --- /dev/null +++ b/drivers/net/ethernet/sfc/tx_common.c @@ -0,0 +1,404 @@ +// SPDX-License-Identifier: GPL-2.0-only +/**************************************************************************** + * Driver for Solarflare network controllers and boards + * Copyright 2018 Solarflare Communications Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation, incorporated herein by reference. + */ + +#include "net_driver.h" +#include "efx.h" +#include "nic.h" +#include "tx_common.h" + +static unsigned int efx_tx_cb_page_count(struct efx_tx_queue *tx_queue) +{ + 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) +{ + struct efx_nic *efx = tx_queue->efx; + unsigned int entries; + int rc; + + /* Create the smallest power-of-two aligned ring */ + entries = max(roundup_pow_of_two(efx->txq_entries), EFX_MIN_DMAQ_SIZE); + EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE); + tx_queue->ptr_mask = entries - 1; + + netif_dbg(efx, probe, efx->net_dev, + "creating TX queue %d size %#x mask %#x\n", + tx_queue->queue, efx->txq_entries, tx_queue->ptr_mask); + + /* Allocate software ring */ + tx_queue->buffer = kcalloc(entries, sizeof(*tx_queue->buffer), + GFP_KERNEL); + if (!tx_queue->buffer) + return -ENOMEM; + + 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 */ + rc = efx_nic_probe_tx(tx_queue); + if (rc) + goto fail2; + + return 0; + +fail2: + kfree(tx_queue->cb_page); + tx_queue->cb_page = NULL; +fail1: + kfree(tx_queue->buffer); + tx_queue->buffer = NULL; + return rc; +} + +void efx_init_tx_queue(struct efx_tx_queue *tx_queue) +{ + 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; + tx_queue->write_count = 0; + tx_queue->packet_write_count = 0; + tx_queue->old_write_count = 0; + tx_queue->read_count = 0; + tx_queue->old_read_count = 0; + tx_queue->empty_read_count = 0 | EFX_EMPTY_COUNT_VALID; + tx_queue->xmit_more_available = false; + tx_queue->timestamping = (efx_ptp_use_mac_tx_timestamps(efx) && + tx_queue->channel == efx_ptp_channel(efx)); + tx_queue->completed_desc_ptr = tx_queue->ptr_mask; + tx_queue->completed_timestamp_major = 0; + tx_queue->completed_timestamp_minor = 0; + + tx_queue->xdp_tx = efx_channel_is_xdp_tx(tx_queue->channel); + + /* Set up default function pointers. These may get replaced by + * efx_nic_init_tx() based off NIC/queue capabilities. + */ + tx_queue->handle_tso = efx_enqueue_skb_tso; + + /* Set up TX descriptor ring */ + efx_nic_init_tx(tx_queue); + + tx_queue->initialised = true; +} + +void efx_fini_tx_queue(struct efx_tx_queue *tx_queue) +{ + struct efx_tx_buffer *buffer; + + netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev, + "shutting down TX queue %d\n", tx_queue->queue); + + if (!tx_queue->buffer) + return; + + /* Free any buffers left in the ring */ + while (tx_queue->read_count != tx_queue->write_count) { + 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); + + ++tx_queue->read_count; + } + tx_queue->xmit_more_available = false; + netdev_tx_reset_queue(tx_queue->core_txq); +} + +void efx_remove_tx_queue(struct efx_tx_queue *tx_queue) +{ + int i; + + if (!tx_queue->buffer) + return; + + netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev, + "destroying TX queue %d\n", tx_queue->queue); + efx_nic_remove_tx(tx_queue); + + 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->cb_page[i]); + kfree(tx_queue->cb_page); + tx_queue->cb_page = NULL; + } + + kfree(tx_queue->buffer); + tx_queue->buffer = NULL; +} + +void efx_dequeue_buffer(struct efx_tx_queue *tx_queue, + struct efx_tx_buffer *buffer, + unsigned int *pkts_compl, + unsigned int *bytes_compl) +{ + if (buffer->unmap_len) { + struct device *dma_dev = &tx_queue->efx->pci_dev->dev; + dma_addr_t unmap_addr = buffer->dma_addr - buffer->dma_offset; + + 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; + } + + if (buffer->flags & EFX_TX_BUF_SKB) { + struct sk_buff *skb = (struct sk_buff *)buffer->skb; + + EFX_WARN_ON_PARANOID(!pkts_compl || !bytes_compl); + (*pkts_compl)++; + (*bytes_compl) += skb->len; + if (tx_queue->timestamping && + (tx_queue->completed_timestamp_major || + tx_queue->completed_timestamp_minor)) { + struct skb_shared_hwtstamps hwtstamp; + + hwtstamp.hwtstamp = + efx_ptp_nic_to_kernel_time(tx_queue); + skb_tstamp_tx(skb, &hwtstamp); + + tx_queue->completed_timestamp_major = 0; + tx_queue->completed_timestamp_minor = 0; + } + dev_consume_skb_any((struct sk_buff *)buffer->skb); + 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_XDP) { + xdp_return_frame_rx_napi(buffer->xdpf); + } + + buffer->len = 0; + buffer->flags = 0; +} + +/* Remove packets from the TX queue + * + * This removes packets from the TX queue, up to and including the + * specified index. + */ +static void efx_dequeue_buffers(struct efx_tx_queue *tx_queue, + unsigned int index, + unsigned int *pkts_compl, + unsigned int *bytes_compl) +{ + struct efx_nic *efx = tx_queue->efx; + unsigned int stop_index, read_ptr; + + stop_index = (index + 1) & tx_queue->ptr_mask; + read_ptr = tx_queue->read_count & tx_queue->ptr_mask; + + while (read_ptr != stop_index) { + struct efx_tx_buffer *buffer = &tx_queue->buffer[read_ptr]; + + if (!(buffer->flags & EFX_TX_BUF_OPTION) && + unlikely(buffer->len == 0)) { + netif_err(efx, tx_err, efx->net_dev, + "TX queue %d spurious TX completion id %x\n", + tx_queue->queue, read_ptr); + efx_schedule_reset(efx, RESET_TYPE_TX_SKIP); + return; + } + + efx_dequeue_buffer(tx_queue, buffer, pkts_compl, bytes_compl); + + ++tx_queue->read_count; + read_ptr = tx_queue->read_count & tx_queue->ptr_mask; + } +} + +void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index) +{ + unsigned int fill_level, pkts_compl = 0, bytes_compl = 0; + struct efx_nic *efx = tx_queue->efx; + struct efx_tx_queue *txq2; + + EFX_WARN_ON_ONCE_PARANOID(index > tx_queue->ptr_mask); + + efx_dequeue_buffers(tx_queue, index, &pkts_compl, &bytes_compl); + tx_queue->pkts_compl += pkts_compl; + tx_queue->bytes_compl += bytes_compl; + + if (pkts_compl > 1) + ++tx_queue->merge_events; + + /* 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))) { + 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); + } + + /* Check whether the hardware queue is now empty */ + if ((int)(tx_queue->read_count - tx_queue->old_write_count) >= 0) { + tx_queue->old_write_count = READ_ONCE(tx_queue->write_count); + if (tx_queue->read_count == tx_queue->old_write_count) { + smp_mb(); + tx_queue->empty_read_count = + tx_queue->read_count | EFX_EMPTY_COUNT_VALID; + } + } +} + +/* Remove buffers put into a tx_queue for the current packet. + * None of the buffers must have an skb attached. + */ +void efx_enqueue_unwind(struct efx_tx_queue *tx_queue, + unsigned int insert_count) +{ + struct efx_tx_buffer *buffer; + unsigned int bytes_compl = 0; + unsigned int pkts_compl = 0; + + /* 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, &pkts_compl, &bytes_compl); + } +} + +struct efx_tx_buffer *efx_tx_map_chunk(struct efx_tx_queue *tx_queue, + dma_addr_t dma_addr, size_t len) +{ + const struct efx_nic_type *nic_type = tx_queue->efx->type; + struct efx_tx_buffer *buffer; + unsigned int dma_len; + + /* 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); + + 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); + + return buffer; +} + +/* Map all data from an SKB for DMA and create descriptors on the queue. */ +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; + + nr_frags = skb_shinfo(skb)->nr_frags; + frag_index = 0; + + /* 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; + + if (unlikely(dma_mapping_error(dma_dev, dma_addr))) + return -EIO; + + 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; + } + } + + /* Add descriptors for each fragment. */ + do { + struct efx_tx_buffer *buffer; + skb_frag_t *fragment; + + buffer = efx_tx_map_chunk(tx_queue, dma_addr, len); + + /* 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; + + 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); + dma_addr = skb_frag_dma_map(dma_dev, fragment, 0, len, + DMA_TO_DEVICE); + dma_flags = 0; + unmap_len = len; + unmap_addr = dma_addr; + + if (unlikely(dma_mapping_error(dma_dev, dma_addr))) + return -EIO; + } while (1); +} + +unsigned int efx_tx_max_skb_descs(struct efx_nic *efx) +{ + /* Header and payload descriptor for each output segment, plus + * one for every input fragment boundary within a segment + */ + unsigned int max_descs = EFX_TSO_MAX_SEGS * 2 + MAX_SKB_FRAGS; + + /* Possibly one more per segment for option descriptors */ + if (efx_nic_rev(efx) >= EFX_REV_HUNT_A0) + max_descs += EFX_TSO_MAX_SEGS; + + /* Possibly more for PCIe page boundaries within input fragments */ + if (PAGE_SIZE > EFX_PAGE_SIZE) + max_descs += max_t(unsigned int, MAX_SKB_FRAGS, + DIV_ROUND_UP(GSO_MAX_SIZE, EFX_PAGE_SIZE)); + + return max_descs; +} |