linux-sg2042/drivers/net/ethernet/sfc/tx.c

884 lines
24 KiB
C

/****************************************************************************
* Driver for Solarflare network controllers and boards
* Copyright 2005-2006 Fen Systems Ltd.
* Copyright 2005-2013 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 <linux/cache.h>
#include "net_driver.h"
#include "efx.h"
#include "io.h"
#include "nic.h"
#include "tx.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_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) {
(*pkts_compl)++;
(*bytes_compl) += buffer->skb->len;
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);
}
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 */
struct efx_tx_queue *txq2 = efx_tx_queue_partner(txq1);
struct efx_nic *efx = txq1->efx;
unsigned int fill_level;
fill_level = max(txq1->insert_count - txq1->old_read_count,
txq2->insert_count - txq2->old_read_count);
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();
txq1->old_read_count = ACCESS_ONCE(txq1->read_count);
txq2->old_read_count = ACCESS_ONCE(txq2->read_count);
fill_level = max(txq1->insert_count - txq1->old_read_count,
txq2->insert_count - txq2->old_read_count);
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 + f->page_offset,
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, &copy_buf);
efx_flush_copy_buffer(tx_queue->efx, piobuf, &copy_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;
}
#endif /* EFX_USE_PIO */
static 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.
*/
static 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. None of the buffers must have
* an skb attached.
*/
static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
{
struct efx_tx_buffer *buffer;
/* Work backwards until we hit the original insert pointer value */
while (tx_queue->insert_count != tx_queue->write_count) {
--tx_queue->insert_count;
buffer = __efx_tx_queue_get_insert_buffer(tx_queue);
efx_dequeue_buffer(tx_queue, buffer, NULL, NULL);
}
}
/*
* Fallback to software TSO.
*
* This is used if we are unable to send a GSO packet through hardware TSO.
* This should only ever happen due to per-queue restrictions - unsupported
* packets should first be filtered by the feature flags.
*
* Returns 0 on success, error code otherwise.
*/
static int efx_tx_tso_fallback(struct efx_tx_queue *tx_queue,
struct sk_buff *skb)
{
struct sk_buff *segments, *next;
segments = skb_gso_segment(skb, 0);
if (IS_ERR(segments))
return PTR_ERR(segments);
dev_kfree_skb_any(skb);
skb = segments;
while (skb) {
next = skb->next;
skb->next = NULL;
if (next)
skb->xmit_more = true;
efx_enqueue_skb(tx_queue, skb);
skb = next;
}
return 0;
}
/*
* 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)
{
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) {
EFX_WARN_ON_ONCE_PARANOID(!tx_queue->handle_tso);
rc = tx_queue->handle_tso(tx_queue, skb, &data_mapped);
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 && !skb->xmit_more &&
efx_nic_may_tx_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;
/* Update BQL */
netdev_tx_sent_queue(tx_queue->core_txq, skb_len);
/* Pass off to hardware */
if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {
struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
/* There could be packets left on the partner queue if those
* SKBs had skb->xmit_more set. If we do not push those they
* could be left for a long time and cause a netdev watchdog.
*/
if (txq2->xmit_more_available)
efx_nic_push_buffers(txq2);
efx_nic_push_buffers(tx_queue);
} else {
tx_queue->xmit_more_available = skb->xmit_more;
}
if (segments) {
tx_queue->tso_bursts++;
tx_queue->tso_packets += segments;
tx_queue->tx_packets += segments;
} else {
tx_queue->tx_packets++;
}
efx_tx_maybe_stop_queue(tx_queue);
return NETDEV_TX_OK;
err:
efx_enqueue_unwind(tx_queue);
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/* 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;
}
}
/* 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));
/* PTP "event" packet */
if (unlikely(efx_xmit_with_hwtstamp(skb)) &&
unlikely(efx_ptp_is_ptp_tx(efx, skb))) {
return efx_ptp_tx(efx, skb);
}
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, enum tc_setup_type type,
void *type_data)
{
struct efx_nic *efx = netdev_priv(net_dev);
struct tc_mqprio_qopt *mqprio = type_data;
struct efx_channel *channel;
struct efx_tx_queue *tx_queue;
unsigned tc, num_tc;
int rc;
if (type != TC_SETUP_MQPRIO)
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;
}
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;
struct efx_tx_queue *txq2;
unsigned int pkts_compl = 0, bytes_compl = 0;
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 = 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;
}
}
}
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;
/* 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;
}