sfc: Move the Solarflare drivers

Moves the Solarflare drivers into drivers/net/ethernet/sfc/ and
make the necessary Kconfig and Makefile changes.

CC: Steve Hodgson <shodgson@solarflare.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 0 insertions, 1212 deletions

diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
deleted file mode 100644
index 84eb99e0f8d2..000000000000
--- a/drivers/net/sfc/tx.c
+++ /dev/null
@@ -1,1212 +0,0 @@
-/****************************************************************************
- * Driver for Solarflare Solarstorm network controllers and boards
- * Copyright 2005-2006 Fen Systems Ltd.
- * Copyright 2005-2010 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 <linux/pci.h>
-#include <linux/tcp.h>
-#include <linux/ip.h>
-#include <linux/in.h>
-#include <linux/ipv6.h>
-#include <linux/slab.h>
-#include <net/ipv6.h>
-#include <linux/if_ether.h>
-#include <linux/highmem.h>
-#include "net_driver.h"
-#include "efx.h"
-#include "nic.h"
-#include "workarounds.h"
-
-/*
- * TX descriptor ring full threshold
- *
- * The tx_queue descriptor ring fill-level must fall below this value
- * before we restart the netif queue
- */
-#define EFX_TXQ_THRESHOLD(_efx) ((_efx)->txq_entries / 2u)
-
-static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue,
-			       struct efx_tx_buffer *buffer)
-{
-	if (buffer->unmap_len) {
-		struct pci_dev *pci_dev = tx_queue->efx->pci_dev;
-		dma_addr_t unmap_addr = (buffer->dma_addr + buffer->len -
-					 buffer->unmap_len);
-		if (buffer->unmap_single)
-			pci_unmap_single(pci_dev, unmap_addr, buffer->unmap_len,
-					 PCI_DMA_TODEVICE);
-		else
-			pci_unmap_page(pci_dev, unmap_addr, buffer->unmap_len,
-				       PCI_DMA_TODEVICE);
-		buffer->unmap_len = 0;
-		buffer->unmap_single = false;
-	}
-
-	if (buffer->skb) {
-		dev_kfree_skb_any((struct sk_buff *) buffer->skb);
-		buffer->skb = NULL;
-		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);
-	}
-}
-
-/**
- * struct efx_tso_header - a DMA mapped buffer for packet headers
- * @next: Linked list of free ones.
- *	The list is protected by the TX queue lock.
- * @dma_unmap_len: Length to unmap for an oversize buffer, or 0.
- * @dma_addr: The DMA address of the header below.
- *
- * This controls the memory used for a TSO header.  Use TSOH_DATA()
- * to find the packet header data.  Use TSOH_SIZE() to calculate the
- * total size required for a given packet header length.  TSO headers
- * in the free list are exactly %TSOH_STD_SIZE bytes in size.
- */
-struct efx_tso_header {
-	union {
-		struct efx_tso_header *next;
-		size_t unmap_len;
-	};
-	dma_addr_t dma_addr;
-};
-
-static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
-			       struct sk_buff *skb);
-static void efx_fini_tso(struct efx_tx_queue *tx_queue);
-static void efx_tsoh_heap_free(struct efx_tx_queue *tx_queue,
-			       struct efx_tso_header *tsoh);
-
-static void efx_tsoh_free(struct efx_tx_queue *tx_queue,
-			  struct efx_tx_buffer *buffer)
-{
-	if (buffer->tsoh) {
-		if (likely(!buffer->tsoh->unmap_len)) {
-			buffer->tsoh->next = tx_queue->tso_headers_free;
-			tx_queue->tso_headers_free = buffer->tsoh;
-		} else {
-			efx_tsoh_heap_free(tx_queue, buffer->tsoh);
-		}
-		buffer->tsoh = NULL;
-	}
-}
-
-
-static inline unsigned
-efx_max_tx_len(struct efx_nic *efx, dma_addr_t dma_addr)
-{
-	/* Depending on the NIC revision, we can use descriptor
-	 * lengths up to 8K or 8K-1.  However, since PCI Express
-	 * devices must split read requests at 4K boundaries, there is
-	 * little benefit from using descriptors that cross those
-	 * boundaries and we keep things simple by not doing so.
-	 */
-	unsigned len = (~dma_addr & 0xfff) + 1;
-
-	/* Work around hardware bug for unaligned buffers. */
-	if (EFX_WORKAROUND_5391(efx) && (dma_addr & 0xf))
-		len = min_t(unsigned, len, 512 - (dma_addr & 0xf));
-
-	return len;
-}
-
-/*
- * 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 or NETDEV_TX_BUSY
- * 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)
-{
-	struct efx_nic *efx = tx_queue->efx;
-	struct pci_dev *pci_dev = efx->pci_dev;
-	struct efx_tx_buffer *buffer;
-	skb_frag_t *fragment;
-	struct page *page;
-	int page_offset;
-	unsigned int len, unmap_len = 0, fill_level, insert_ptr;
-	dma_addr_t dma_addr, unmap_addr = 0;
-	unsigned int dma_len;
-	bool unmap_single;
-	int q_space, i = 0;
-	netdev_tx_t rc = NETDEV_TX_OK;
-
-	EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count);
-
-	if (skb_shinfo(skb)->gso_size)
-		return efx_enqueue_skb_tso(tx_queue, skb);
-
-	/* Get size of the initial fragment */
-	len = skb_headlen(skb);
-
-	/* Pad if necessary */
-	if (EFX_WORKAROUND_15592(efx) && skb->len <= 32) {
-		EFX_BUG_ON_PARANOID(skb->data_len);
-		len = 32 + 1;
-		if (skb_pad(skb, len - skb->len))
-			return NETDEV_TX_OK;
-	}
-
-	fill_level = tx_queue->insert_count - tx_queue->old_read_count;
-	q_space = efx->txq_entries - 1 - fill_level;
-
-	/* Map for DMA.  Use pci_map_single rather than pci_map_page
-	 * since this is more efficient on machines with sparse
-	 * memory.
-	 */
-	unmap_single = true;
-	dma_addr = pci_map_single(pci_dev, skb->data, len, PCI_DMA_TODEVICE);
-
-	/* Process all fragments */
-	while (1) {
-		if (unlikely(pci_dma_mapping_error(pci_dev, dma_addr)))
-			goto pci_err;
-
-		/* Store fields for marking in the per-fragment final
-		 * descriptor */
-		unmap_len = len;
-		unmap_addr = dma_addr;
-
-		/* Add to TX queue, splitting across DMA boundaries */
-		do {
-			if (unlikely(q_space-- <= 0)) {
-				/* It might be that completions have
-				 * happened since the xmit path last
-				 * checked.  Update the xmit path's
-				 * copy of read_count.
-				 */
-				netif_tx_stop_queue(tx_queue->core_txq);
-				/* This memory barrier protects the
-				 * change of queue state from the access
-				 * of read_count. */
-				smp_mb();
-				tx_queue->old_read_count =
-					ACCESS_ONCE(tx_queue->read_count);
-				fill_level = (tx_queue->insert_count
-					      - tx_queue->old_read_count);
-				q_space = efx->txq_entries - 1 - fill_level;
-				if (unlikely(q_space-- <= 0)) {
-					rc = NETDEV_TX_BUSY;
-					goto unwind;
-				}
-				smp_mb();
-				if (likely(!efx->loopback_selftest))
-					netif_tx_start_queue(
-						tx_queue->core_txq);
-			}
-
-			insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
-			buffer = &tx_queue->buffer[insert_ptr];
-			efx_tsoh_free(tx_queue, buffer);
-			EFX_BUG_ON_PARANOID(buffer->tsoh);
-			EFX_BUG_ON_PARANOID(buffer->skb);
-			EFX_BUG_ON_PARANOID(buffer->len);
-			EFX_BUG_ON_PARANOID(!buffer->continuation);
-			EFX_BUG_ON_PARANOID(buffer->unmap_len);
-
-			dma_len = efx_max_tx_len(efx, dma_addr);
-			if (likely(dma_len >= len))
-				dma_len = len;
-
-			/* Fill out per descriptor fields */
-			buffer->len = dma_len;
-			buffer->dma_addr = dma_addr;
-			len -= dma_len;
-			dma_addr += dma_len;
-			++tx_queue->insert_count;
-		} while (len);
-
-		/* Transfer ownership of the unmapping to the final buffer */
-		buffer->unmap_single = unmap_single;
-		buffer->unmap_len = unmap_len;
-		unmap_len = 0;
-
-		/* Get address and size of next fragment */
-		if (i >= skb_shinfo(skb)->nr_frags)
-			break;
-		fragment = &skb_shinfo(skb)->frags[i];
-		len = fragment->size;
-		page = fragment->page;
-		page_offset = fragment->page_offset;
-		i++;
-		/* Map for DMA */
-		unmap_single = false;
-		dma_addr = pci_map_page(pci_dev, page, page_offset, len,
-					PCI_DMA_TODEVICE);
-	}
-
-	/* Transfer ownership of the skb to the final buffer */
-	buffer->skb = skb;
-	buffer->continuation = false;
-
-	/* Pass off to hardware */
-	efx_nic_push_buffers(tx_queue);
-
-	return NETDEV_TX_OK;
-
- pci_err:
-	netif_err(efx, tx_err, efx->net_dev,
-		  " TX queue %d could not map skb with %d bytes %d "
-		  "fragments for DMA\n", tx_queue->queue, skb->len,
-		  skb_shinfo(skb)->nr_frags + 1);
-
-	/* Mark the packet as transmitted, and free the SKB ourselves */
-	dev_kfree_skb_any(skb);
-
- unwind:
-	/* Work backwards until we hit the original insert pointer value */
-	while (tx_queue->insert_count != tx_queue->write_count) {
-		--tx_queue->insert_count;
-		insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
-		buffer = &tx_queue->buffer[insert_ptr];
-		efx_dequeue_buffer(tx_queue, buffer);
-		buffer->len = 0;
-	}
-
-	/* Free the fragment we were mid-way through pushing */
-	if (unmap_len) {
-		if (unmap_single)
-			pci_unmap_single(pci_dev, unmap_addr, unmap_len,
-					 PCI_DMA_TODEVICE);
-		else
-			pci_unmap_page(pci_dev, unmap_addr, unmap_len,
-				       PCI_DMA_TODEVICE);
-	}
-
-	return rc;
-}
-
-/* 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)
-{
-	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 (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);
-		buffer->continuation = true;
-		buffer->len = 0;
-
-		++tx_queue->read_count;
-		read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
-	}
-}
-
-/* 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));
-
-	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, u8 num_tc)
-{
-	struct efx_nic *efx = netdev_priv(net_dev);
-	struct efx_channel *channel;
-	struct efx_tx_queue *tx_queue;
-	unsigned tc;
-	int rc;
-
-	if (efx_nic_rev(efx) < EFX_REV_FALCON_B0 || num_tc > EFX_MAX_TX_TC)
-		return -EINVAL;
-
-	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;
-}
-
-void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index)
-{
-	unsigned fill_level;
-	struct efx_nic *efx = tx_queue->efx;
-
-	EFX_BUG_ON_PARANOID(index > tx_queue->ptr_mask);
-
-	efx_dequeue_buffers(tx_queue, index);
-
-	/* See if we need to restart the netif queue.  This barrier
-	 * separates the update of read_count from the test of the
-	 * queue state. */
-	smp_mb();
-	if (unlikely(netif_tx_queue_stopped(tx_queue->core_txq)) &&
-	    likely(efx->port_enabled) &&
-	    likely(netif_device_present(efx->net_dev))) {
-		fill_level = tx_queue->insert_count - tx_queue->read_count;
-		if (fill_level < EFX_TXQ_THRESHOLD(efx)) {
-			EFX_BUG_ON_PARANOID(!efx_dev_registered(efx));
-			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 = ACCESS_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;
-		}
-	}
-}
-
-int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
-{
-	struct efx_nic *efx = tx_queue->efx;
-	unsigned int entries;
-	int i, rc;
-
-	/* Create the smallest power-of-two aligned ring */
-	entries = max(roundup_pow_of_two(efx->txq_entries), EFX_MIN_DMAQ_SIZE);
-	EFX_BUG_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 = kzalloc(entries * sizeof(*tx_queue->buffer),
-				   GFP_KERNEL);
-	if (!tx_queue->buffer)
-		return -ENOMEM;
-	for (i = 0; i <= tx_queue->ptr_mask; ++i)
-		tx_queue->buffer[i].continuation = true;
-
-	/* Allocate hardware ring */
-	rc = efx_nic_probe_tx(tx_queue);
-	if (rc)
-		goto fail;
-
-	return 0;
-
- fail:
-	kfree(tx_queue->buffer);
-	tx_queue->buffer = NULL;
-	return rc;
-}
-
-void efx_init_tx_queue(struct efx_tx_queue *tx_queue)
-{
-	netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev,
-		  "initialising TX queue %d\n", tx_queue->queue);
-
-	tx_queue->insert_count = 0;
-	tx_queue->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;
-
-	/* Set up TX descriptor ring */
-	efx_nic_init_tx(tx_queue);
-
-	tx_queue->initialised = true;
-}
-
-void efx_release_tx_buffers(struct efx_tx_queue *tx_queue)
-{
-	struct efx_tx_buffer *buffer;
-
-	if (!tx_queue->buffer)
-		return;
-
-	/* Free any buffers left in the ring */
-	while (tx_queue->read_count != tx_queue->write_count) {
-		buffer = &tx_queue->buffer[tx_queue->read_count & tx_queue->ptr_mask];
-		efx_dequeue_buffer(tx_queue, buffer);
-		buffer->continuation = true;
-		buffer->len = 0;
-
-		++tx_queue->read_count;
-	}
-}
-
-void efx_fini_tx_queue(struct efx_tx_queue *tx_queue)
-{
-	if (!tx_queue->initialised)
-		return;
-
-	netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev,
-		  "shutting down TX queue %d\n", tx_queue->queue);
-
-	tx_queue->initialised = false;
-
-	/* Flush TX queue, remove descriptor ring */
-	efx_nic_fini_tx(tx_queue);
-
-	efx_release_tx_buffers(tx_queue);
-
-	/* Free up TSO header cache */
-	efx_fini_tso(tx_queue);
-}
-
-void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
-{
-	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);
-
-	kfree(tx_queue->buffer);
-	tx_queue->buffer = NULL;
-}
-
-
-/* Efx TCP segmentation acceleration.
- *
- * Why?  Because by doing it here in the driver we can go significantly
- * faster than the GSO.
- *
- * Requires TX checksum offload support.
- */
-
-/* Number of bytes inserted at the start of a TSO header buffer,
- * similar to NET_IP_ALIGN.
- */
-#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
-#define TSOH_OFFSET	0
-#else
-#define TSOH_OFFSET	NET_IP_ALIGN
-#endif
-
-#define TSOH_BUFFER(tsoh)	((u8 *)(tsoh + 1) + TSOH_OFFSET)
-
-/* Total size of struct efx_tso_header, buffer and padding */
-#define TSOH_SIZE(hdr_len)					\
-	(sizeof(struct efx_tso_header) + TSOH_OFFSET + hdr_len)
-
-/* Size of blocks on free list.  Larger blocks must be allocated from
- * the heap.
- */
-#define TSOH_STD_SIZE		128
-
-#define PTR_DIFF(p1, p2)  ((u8 *)(p1) - (u8 *)(p2))
-#define ETH_HDR_LEN(skb)  (skb_network_header(skb) - (skb)->data)
-#define SKB_TCP_OFF(skb)  PTR_DIFF(tcp_hdr(skb), (skb)->data)
-#define SKB_IPV4_OFF(skb) PTR_DIFF(ip_hdr(skb), (skb)->data)
-#define SKB_IPV6_OFF(skb) PTR_DIFF(ipv6_hdr(skb), (skb)->data)
-
-/**
- * struct tso_state - TSO state for an SKB
- * @out_len: Remaining length in current segment
- * @seqnum: Current sequence number
- * @ipv4_id: Current IPv4 ID, host endian
- * @packet_space: Remaining space in current packet
- * @dma_addr: DMA address of current position
- * @in_len: Remaining length in current SKB fragment
- * @unmap_len: Length of SKB fragment
- * @unmap_addr: DMA address of SKB fragment
- * @unmap_single: DMA single vs page mapping flag
- * @protocol: Network protocol (after any VLAN header)
- * @header_len: Number of bytes of header
- * @full_packet_size: Number of bytes to put in each outgoing segment
- *
- * The state used during segmentation.  It is put into this data structure
- * just to make it easy to pass into inline functions.
- */
-struct tso_state {
-	/* Output position */
-	unsigned out_len;
-	unsigned seqnum;
-	unsigned ipv4_id;
-	unsigned packet_space;
-
-	/* Input position */
-	dma_addr_t dma_addr;
-	unsigned in_len;
-	unsigned unmap_len;
-	dma_addr_t unmap_addr;
-	bool unmap_single;
-
-	__be16 protocol;
-	unsigned header_len;
-	int full_packet_size;
-};
-
-
-/*
- * Verify that our various assumptions about sk_buffs and the conditions
- * under which TSO will be attempted hold true.  Return the protocol number.
- */
-static __be16 efx_tso_check_protocol(struct sk_buff *skb)
-{
-	__be16 protocol = skb->protocol;
-
-	EFX_BUG_ON_PARANOID(((struct ethhdr *)skb->data)->h_proto !=
-			    protocol);
-	if (protocol == htons(ETH_P_8021Q)) {
-		/* Find the encapsulated protocol; reset network header
-		 * and transport header based on that. */
-		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
-		protocol = veh->h_vlan_encapsulated_proto;
-		skb_set_network_header(skb, sizeof(*veh));
-		if (protocol == htons(ETH_P_IP))
-			skb_set_transport_header(skb, sizeof(*veh) +
-						 4 * ip_hdr(skb)->ihl);
-		else if (protocol == htons(ETH_P_IPV6))
-			skb_set_transport_header(skb, sizeof(*veh) +
-						 sizeof(struct ipv6hdr));
-	}
-
-	if (protocol == htons(ETH_P_IP)) {
-		EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP);
-	} else {
-		EFX_BUG_ON_PARANOID(protocol != htons(ETH_P_IPV6));
-		EFX_BUG_ON_PARANOID(ipv6_hdr(skb)->nexthdr != NEXTHDR_TCP);
-	}
-	EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb), skb->data)
-			     + (tcp_hdr(skb)->doff << 2u)) >
-			    skb_headlen(skb));
-
-	return protocol;
-}
-
-
-/*
- * Allocate a page worth of efx_tso_header structures, and string them
- * into the tx_queue->tso_headers_free linked list. Return 0 or -ENOMEM.
- */
-static int efx_tsoh_block_alloc(struct efx_tx_queue *tx_queue)
-{
-
-	struct pci_dev *pci_dev = tx_queue->efx->pci_dev;
-	struct efx_tso_header *tsoh;
-	dma_addr_t dma_addr;
-	u8 *base_kva, *kva;
-
-	base_kva = pci_alloc_consistent(pci_dev, PAGE_SIZE, &dma_addr);
-	if (base_kva == NULL) {
-		netif_err(tx_queue->efx, tx_err, tx_queue->efx->net_dev,
-			  "Unable to allocate page for TSO headers\n");
-		return -ENOMEM;
-	}
-
-	/* pci_alloc_consistent() allocates pages. */
-	EFX_BUG_ON_PARANOID(dma_addr & (PAGE_SIZE - 1u));
-
-	for (kva = base_kva; kva < base_kva + PAGE_SIZE; kva += TSOH_STD_SIZE) {
-		tsoh = (struct efx_tso_header *)kva;
-		tsoh->dma_addr = dma_addr + (TSOH_BUFFER(tsoh) - base_kva);
-		tsoh->next = tx_queue->tso_headers_free;
-		tx_queue->tso_headers_free = tsoh;
-	}
-
-	return 0;
-}
-
-
-/* Free up a TSO header, and all others in the same page. */
-static void efx_tsoh_block_free(struct efx_tx_queue *tx_queue,
-				struct efx_tso_header *tsoh,
-				struct pci_dev *pci_dev)
-{
-	struct efx_tso_header **p;
-	unsigned long base_kva;
-	dma_addr_t base_dma;
-
-	base_kva = (unsigned long)tsoh & PAGE_MASK;
-	base_dma = tsoh->dma_addr & PAGE_MASK;
-
-	p = &tx_queue->tso_headers_free;
-	while (*p != NULL) {
-		if (((unsigned long)*p & PAGE_MASK) == base_kva)
-			*p = (*p)->next;
-		else
-			p = &(*p)->next;
-	}
-
-	pci_free_consistent(pci_dev, PAGE_SIZE, (void *)base_kva, base_dma);
-}
-
-static struct efx_tso_header *
-efx_tsoh_heap_alloc(struct efx_tx_queue *tx_queue, size_t header_len)
-{
-	struct efx_tso_header *tsoh;
-
-	tsoh = kmalloc(TSOH_SIZE(header_len), GFP_ATOMIC | GFP_DMA);
-	if (unlikely(!tsoh))
-		return NULL;
-
-	tsoh->dma_addr = pci_map_single(tx_queue->efx->pci_dev,
-					TSOH_BUFFER(tsoh), header_len,
-					PCI_DMA_TODEVICE);
-	if (unlikely(pci_dma_mapping_error(tx_queue->efx->pci_dev,
-					   tsoh->dma_addr))) {
-		kfree(tsoh);
-		return NULL;
-	}
-
-	tsoh->unmap_len = header_len;
-	return tsoh;
-}
-
-static void
-efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, struct efx_tso_header *tsoh)
-{
-	pci_unmap_single(tx_queue->efx->pci_dev,
-			 tsoh->dma_addr, tsoh->unmap_len,
-			 PCI_DMA_TODEVICE);
-	kfree(tsoh);
-}
-
-/**
- * efx_tx_queue_insert - push descriptors onto the TX queue
- * @tx_queue:		Efx TX queue
- * @dma_addr:		DMA address of fragment
- * @len:		Length of fragment
- * @final_buffer:	The final buffer inserted into the queue
- *
- * Push descriptors onto the TX queue.  Return 0 on success or 1 if
- * @tx_queue full.
- */
-static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
-			       dma_addr_t dma_addr, unsigned len,
-			       struct efx_tx_buffer **final_buffer)
-{
-	struct efx_tx_buffer *buffer;
-	struct efx_nic *efx = tx_queue->efx;
-	unsigned dma_len, fill_level, insert_ptr;
-	int q_space;
-
-	EFX_BUG_ON_PARANOID(len <= 0);
-
-	fill_level = tx_queue->insert_count - tx_queue->old_read_count;
-	/* -1 as there is no way to represent all descriptors used */
-	q_space = efx->txq_entries - 1 - fill_level;
-
-	while (1) {
-		if (unlikely(q_space-- <= 0)) {
-			/* It might be that completions have happened
-			 * since the xmit path last checked.  Update
-			 * the xmit path's copy of read_count.
-			 */
-			netif_tx_stop_queue(tx_queue->core_txq);
-			/* This memory barrier protects the change of
-			 * queue state from the access of read_count. */
-			smp_mb();
-			tx_queue->old_read_count =
-				ACCESS_ONCE(tx_queue->read_count);
-			fill_level = (tx_queue->insert_count
-				      - tx_queue->old_read_count);
-			q_space = efx->txq_entries - 1 - fill_level;
-			if (unlikely(q_space-- <= 0)) {
-				*final_buffer = NULL;
-				return 1;
-			}
-			smp_mb();
-			netif_tx_start_queue(tx_queue->core_txq);
-		}
-
-		insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
-		buffer = &tx_queue->buffer[insert_ptr];
-		++tx_queue->insert_count;
-
-		EFX_BUG_ON_PARANOID(tx_queue->insert_count -
-				    tx_queue->read_count >=
-				    efx->txq_entries);
-
-		efx_tsoh_free(tx_queue, buffer);
-		EFX_BUG_ON_PARANOID(buffer->len);
-		EFX_BUG_ON_PARANOID(buffer->unmap_len);
-		EFX_BUG_ON_PARANOID(buffer->skb);
-		EFX_BUG_ON_PARANOID(!buffer->continuation);
-		EFX_BUG_ON_PARANOID(buffer->tsoh);
-
-		buffer->dma_addr = dma_addr;
-
-		dma_len = efx_max_tx_len(efx, dma_addr);
-
-		/* If there is enough space to send then do so */
-		if (dma_len >= len)
-			break;
-
-		buffer->len = dma_len; /* Don't set the other members */
-		dma_addr += dma_len;
-		len -= dma_len;
-	}
-
-	EFX_BUG_ON_PARANOID(!len);
-	buffer->len = len;
-	*final_buffer = buffer;
-	return 0;
-}
-
-
-/*
- * Put a TSO header into the TX queue.
- *
- * This is special-cased because we know that it is small enough to fit in
- * a single fragment, and we know it doesn't cross a page boundary.  It
- * also allows us to not worry about end-of-packet etc.
- */
-static void efx_tso_put_header(struct efx_tx_queue *tx_queue,
-			       struct efx_tso_header *tsoh, unsigned len)
-{
-	struct efx_tx_buffer *buffer;
-
-	buffer = &tx_queue->buffer[tx_queue->insert_count & tx_queue->ptr_mask];
-	efx_tsoh_free(tx_queue, buffer);
-	EFX_BUG_ON_PARANOID(buffer->len);
-	EFX_BUG_ON_PARANOID(buffer->unmap_len);
-	EFX_BUG_ON_PARANOID(buffer->skb);
-	EFX_BUG_ON_PARANOID(!buffer->continuation);
-	EFX_BUG_ON_PARANOID(buffer->tsoh);
-	buffer->len = len;
-	buffer->dma_addr = tsoh->dma_addr;
-	buffer->tsoh = tsoh;
-
-	++tx_queue->insert_count;
-}
-
-
-/* Remove descriptors put into a tx_queue. */
-static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
-{
-	struct efx_tx_buffer *buffer;
-	dma_addr_t unmap_addr;
-
-	/* Work backwards until we hit the original insert pointer value */
-	while (tx_queue->insert_count != tx_queue->write_count) {
-		--tx_queue->insert_count;
-		buffer = &tx_queue->buffer[tx_queue->insert_count &
-					   tx_queue->ptr_mask];
-		efx_tsoh_free(tx_queue, buffer);
-		EFX_BUG_ON_PARANOID(buffer->skb);
-		if (buffer->unmap_len) {
-			unmap_addr = (buffer->dma_addr + buffer->len -
-				      buffer->unmap_len);
-			if (buffer->unmap_single)
-				pci_unmap_single(tx_queue->efx->pci_dev,
-						 unmap_addr, buffer->unmap_len,
-						 PCI_DMA_TODEVICE);
-			else
-				pci_unmap_page(tx_queue->efx->pci_dev,
-					       unmap_addr, buffer->unmap_len,
-					       PCI_DMA_TODEVICE);
-			buffer->unmap_len = 0;
-		}
-		buffer->len = 0;
-		buffer->continuation = true;
-	}
-}
-
-
-/* Parse the SKB header and initialise state. */
-static void tso_start(struct tso_state *st, const struct sk_buff *skb)
-{
-	/* All ethernet/IP/TCP headers combined size is TCP header size
-	 * plus offset of TCP header relative to start of packet.
-	 */
-	st->header_len = ((tcp_hdr(skb)->doff << 2u)
-			  + PTR_DIFF(tcp_hdr(skb), skb->data));
-	st->full_packet_size = st->header_len + skb_shinfo(skb)->gso_size;
-
-	if (st->protocol == htons(ETH_P_IP))
-		st->ipv4_id = ntohs(ip_hdr(skb)->id);
-	else
-		st->ipv4_id = 0;
-	st->seqnum = ntohl(tcp_hdr(skb)->seq);
-
-	EFX_BUG_ON_PARANOID(tcp_hdr(skb)->urg);
-	EFX_BUG_ON_PARANOID(tcp_hdr(skb)->syn);
-	EFX_BUG_ON_PARANOID(tcp_hdr(skb)->rst);
-
-	st->packet_space = st->full_packet_size;
-	st->out_len = skb->len - st->header_len;
-	st->unmap_len = 0;
-	st->unmap_single = false;
-}
-
-static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
-			    skb_frag_t *frag)
-{
-	st->unmap_addr = pci_map_page(efx->pci_dev, frag->page,
-				      frag->page_offset, frag->size,
-				      PCI_DMA_TODEVICE);
-	if (likely(!pci_dma_mapping_error(efx->pci_dev, st->unmap_addr))) {
-		st->unmap_single = false;
-		st->unmap_len = frag->size;
-		st->in_len = frag->size;
-		st->dma_addr = st->unmap_addr;
-		return 0;
-	}
-	return -ENOMEM;
-}
-
-static int tso_get_head_fragment(struct tso_state *st, struct efx_nic *efx,
-				 const struct sk_buff *skb)
-{
-	int hl = st->header_len;
-	int len = skb_headlen(skb) - hl;
-
-	st->unmap_addr = pci_map_single(efx->pci_dev, skb->data + hl,
-					len, PCI_DMA_TODEVICE);
-	if (likely(!pci_dma_mapping_error(efx->pci_dev, st->unmap_addr))) {
-		st->unmap_single = true;
-		st->unmap_len = len;
-		st->in_len = len;
-		st->dma_addr = st->unmap_addr;
-		return 0;
-	}
-	return -ENOMEM;
-}
-
-
-/**
- * tso_fill_packet_with_fragment - form descriptors for the current fragment
- * @tx_queue:		Efx TX queue
- * @skb:		Socket buffer
- * @st:			TSO state
- *
- * Form descriptors for the current fragment, until we reach the end
- * of fragment or end-of-packet.  Return 0 on success, 1 if not enough
- * space in @tx_queue.
- */
-static int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue,
-					 const struct sk_buff *skb,
-					 struct tso_state *st)
-{
-	struct efx_tx_buffer *buffer;
-	int n, end_of_packet, rc;
-
-	if (st->in_len == 0)
-		return 0;
-	if (st->packet_space == 0)
-		return 0;
-
-	EFX_BUG_ON_PARANOID(st->in_len <= 0);
-	EFX_BUG_ON_PARANOID(st->packet_space <= 0);
-
-	n = min(st->in_len, st->packet_space);
-
-	st->packet_space -= n;
-	st->out_len -= n;
-	st->in_len -= n;
-
-	rc = efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer);
-	if (likely(rc == 0)) {
-		if (st->out_len == 0)
-			/* Transfer ownership of the skb */
-			buffer->skb = skb;
-
-		end_of_packet = st->out_len == 0 || st->packet_space == 0;
-		buffer->continuation = !end_of_packet;
-
-		if (st->in_len == 0) {
-			/* Transfer ownership of the pci mapping */
-			buffer->unmap_len = st->unmap_len;
-			buffer->unmap_single = st->unmap_single;
-			st->unmap_len = 0;
-		}
-	}
-
-	st->dma_addr += n;
-	return rc;
-}
-
-
-/**
- * tso_start_new_packet - generate a new header and prepare for the new packet
- * @tx_queue:		Efx TX queue
- * @skb:		Socket buffer
- * @st:			TSO state
- *
- * Generate a new header and prepare for the new packet.  Return 0 on
- * success, or -1 if failed to alloc header.
- */
-static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
-				const struct sk_buff *skb,
-				struct tso_state *st)
-{
-	struct efx_tso_header *tsoh;
-	struct tcphdr *tsoh_th;
-	unsigned ip_length;
-	u8 *header;
-
-	/* Allocate a DMA-mapped header buffer. */
-	if (likely(TSOH_SIZE(st->header_len) <= TSOH_STD_SIZE)) {
-		if (tx_queue->tso_headers_free == NULL) {
-			if (efx_tsoh_block_alloc(tx_queue))
-				return -1;
-		}
-		EFX_BUG_ON_PARANOID(!tx_queue->tso_headers_free);
-		tsoh = tx_queue->tso_headers_free;
-		tx_queue->tso_headers_free = tsoh->next;
-		tsoh->unmap_len = 0;
-	} else {
-		tx_queue->tso_long_headers++;
-		tsoh = efx_tsoh_heap_alloc(tx_queue, st->header_len);
-		if (unlikely(!tsoh))
-			return -1;
-	}
-
-	header = TSOH_BUFFER(tsoh);
-	tsoh_th = (struct tcphdr *)(header + SKB_TCP_OFF(skb));
-
-	/* Copy and update the headers. */
-	memcpy(header, skb->data, st->header_len);
-
-	tsoh_th->seq = htonl(st->seqnum);
-	st->seqnum += skb_shinfo(skb)->gso_size;
-	if (st->out_len > skb_shinfo(skb)->gso_size) {
-		/* This packet will not finish the TSO burst. */
-		ip_length = st->full_packet_size - ETH_HDR_LEN(skb);
-		tsoh_th->fin = 0;
-		tsoh_th->psh = 0;
-	} else {
-		/* This packet will be the last in the TSO burst. */
-		ip_length = st->header_len - ETH_HDR_LEN(skb) + st->out_len;
-		tsoh_th->fin = tcp_hdr(skb)->fin;
-		tsoh_th->psh = tcp_hdr(skb)->psh;
-	}
-
-	if (st->protocol == htons(ETH_P_IP)) {
-		struct iphdr *tsoh_iph =
-			(struct iphdr *)(header + SKB_IPV4_OFF(skb));
-
-		tsoh_iph->tot_len = htons(ip_length);
-
-		/* Linux leaves suitable gaps in the IP ID space for us to fill. */
-		tsoh_iph->id = htons(st->ipv4_id);
-		st->ipv4_id++;
-	} else {
-		struct ipv6hdr *tsoh_iph =
-			(struct ipv6hdr *)(header + SKB_IPV6_OFF(skb));
-
-		tsoh_iph->payload_len = htons(ip_length - sizeof(*tsoh_iph));
-	}
-
-	st->packet_space = skb_shinfo(skb)->gso_size;
-	++tx_queue->tso_packets;
-
-	/* Form a descriptor for this header. */
-	efx_tso_put_header(tx_queue, tsoh, st->header_len);
-
-	return 0;
-}
-
-
-/**
- * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer
- * @tx_queue:		Efx TX queue
- * @skb:		Socket buffer
- *
- * Context: You must hold netif_tx_lock() to call this function.
- *
- * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if
- * @skb was not enqueued.  In all cases @skb is consumed.  Return
- * %NETDEV_TX_OK or %NETDEV_TX_BUSY.
- */
-static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
-			       struct sk_buff *skb)
-{
-	struct efx_nic *efx = tx_queue->efx;
-	int frag_i, rc, rc2 = NETDEV_TX_OK;
-	struct tso_state state;
-
-	/* Find the packet protocol and sanity-check it */
-	state.protocol = efx_tso_check_protocol(skb);
-
-	EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count);
-
-	tso_start(&state, skb);
-
-	/* Assume that skb header area contains exactly the headers, and
-	 * all payload is in the frag list.
-	 */
-	if (skb_headlen(skb) == state.header_len) {
-		/* Grab the first payload fragment. */
-		EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1);
-		frag_i = 0;
-		rc = tso_get_fragment(&state, efx,
-				      skb_shinfo(skb)->frags + frag_i);
-		if (rc)
-			goto mem_err;
-	} else {
-		rc = tso_get_head_fragment(&state, efx, skb);
-		if (rc)
-			goto mem_err;
-		frag_i = -1;
-	}
-
-	if (tso_start_new_packet(tx_queue, skb, &state) < 0)
-		goto mem_err;
-
-	while (1) {
-		rc = tso_fill_packet_with_fragment(tx_queue, skb, &state);
-		if (unlikely(rc)) {
-			rc2 = NETDEV_TX_BUSY;
-			goto unwind;
-		}
-
-		/* Move onto the next fragment? */
-		if (state.in_len == 0) {
-			if (++frag_i >= skb_shinfo(skb)->nr_frags)
-				/* End of payload reached. */
-				break;
-			rc = tso_get_fragment(&state, efx,
-					      skb_shinfo(skb)->frags + frag_i);
-			if (rc)
-				goto mem_err;
-		}
-
-		/* Start at new packet? */
-		if (state.packet_space == 0 &&
-		    tso_start_new_packet(tx_queue, skb, &state) < 0)
-			goto mem_err;
-	}
-
-	/* Pass off to hardware */
-	efx_nic_push_buffers(tx_queue);
-
-	tx_queue->tso_bursts++;
-	return NETDEV_TX_OK;
-
- mem_err:
-	netif_err(efx, tx_err, efx->net_dev,
-		  "Out of memory for TSO headers, or PCI mapping error\n");
-	dev_kfree_skb_any(skb);
-
- unwind:
-	/* Free the DMA mapping we were in the process of writing out */
-	if (state.unmap_len) {
-		if (state.unmap_single)
-			pci_unmap_single(efx->pci_dev, state.unmap_addr,
-					 state.unmap_len, PCI_DMA_TODEVICE);
-		else
-			pci_unmap_page(efx->pci_dev, state.unmap_addr,
-				       state.unmap_len, PCI_DMA_TODEVICE);
-	}
-
-	efx_enqueue_unwind(tx_queue);
-	return rc2;
-}
-
-
-/*
- * Free up all TSO datastructures associated with tx_queue. This
- * routine should be called only once the tx_queue is both empty and
- * will no longer be used.
- */
-static void efx_fini_tso(struct efx_tx_queue *tx_queue)
-{
-	unsigned i;
-
-	if (tx_queue->buffer) {
-		for (i = 0; i <= tx_queue->ptr_mask; ++i)
-			efx_tsoh_free(tx_queue, &tx_queue->buffer[i]);
-	}
-
-	while (tx_queue->tso_headers_free != NULL)
-		efx_tsoh_block_free(tx_queue, tx_queue->tso_headers_free,
-				    tx_queue->efx->pci_dev);
-}