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authorAlex Maftei (amaftei) <amaftei@solarflare.com>2020-01-08 16:14:00 +0000
committerDavid S. Miller <davem@davemloft.net>2020-01-08 13:28:03 -0800
commit17d3b21c7ba82cd88855a798b931bb3ac1388cba (patch)
tree3e146ba607277dc4921b5f77225085c7fd1c2ae6 /drivers/net/ethernet/sfc/tx_common.c
parent1751cc365f58ea69714be1c8ba718236354cd719 (diff)
sfc: move common tx code
Once again, a tiny bit of refactoring was required to stitch the code together (i.e. adding headers). The moved code deals with managing tx queues and mappings. Signed-off-by: Alexandru-Mihai Maftei <amaftei@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/sfc/tx_common.c')
-rw-r--r--drivers/net/ethernet/sfc/tx_common.c310
1 files changed, 310 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..e29ade21c4b9
--- /dev/null
+++ b/drivers/net/ethernet/sfc/tx_common.c
@@ -0,0 +1,310 @@
+// 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;
+}
+
+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;
+}