From: "Alex Maftei (amaftei)" <amaftei@solarflare.com>
Date: Wed, 8 Jan 2020 16:14:00 +0000
Subject: sfc: move common tx code
Patch-mainline: v5.6-rc1
Git-commit: 17d3b21c7ba82cd88855a798b931bb3ac1388cba
References: jsc#SLE-8314
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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/sfc/Makefile | 2
drivers/net/ethernet/sfc/tx.c | 295 ---------------------------------
drivers/net/ethernet/sfc/tx_common.c | 310 +++++++++++++++++++++++++++++++++++
3 files changed, 311 insertions(+), 296 deletions(-)
create mode 100644 drivers/net/ethernet/sfc/tx_common.c
--- a/drivers/net/ethernet/sfc/Makefile
+++ b/drivers/net/ethernet/sfc/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
sfc-y += efx.o efx_common.o efx_channels.o nic.o \
farch.o siena.o ef10.o \
- tx.o rx.o rx_common.o \
+ tx.o tx_common.o rx.o rx_common.o \
selftest.o ethtool.o ptp.o tx_tso.o \
mcdi.o mcdi_port.o \
mcdi_mon.o
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -57,72 +57,6 @@ u8 *efx_tx_get_copy_buffer_limited(struc
return efx_tx_get_copy_buffer(tx_queue, buffer);
}
-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;
-}
-
-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;
-}
-
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 */
@@ -334,107 +268,6 @@ static int efx_enqueue_skb_pio(struct ef
}
#endif /* EFX_USE_PIO */
-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);
-}
-
/* Remove buffers put into a tx_queue for the current packet.
* None of the buffers must have an skb attached.
*/
@@ -877,131 +710,3 @@ void efx_xmit_done(struct efx_tx_queue *
}
}
}
-
-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;
-}
--- /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;
+}