blob: b9369483758cd6ebcd263852542175610b4d2789 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/****************************************************************************
* Driver for Solarflare network controllers and boards
* Copyright 2005-2006 Fen Systems Ltd.
* Copyright 2005-2013 Solarflare Communications Inc.
*/
#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"
static inline u8 *ef4_tx_get_copy_buffer(struct ef4_tx_queue *tx_queue,
struct ef4_tx_buffer *buffer)
{
unsigned int index = ef4_tx_queue_get_insert_index(tx_queue);
struct ef4_buffer *page_buf =
&tx_queue->cb_page[index >> (PAGE_SHIFT - EF4_TX_CB_ORDER)];
unsigned int offset =
((index << EF4_TX_CB_ORDER) + NET_IP_ALIGN) & (PAGE_SIZE - 1);
if (unlikely(!page_buf->addr) &&
ef4_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 *ef4_tx_get_copy_buffer_limited(struct ef4_tx_queue *tx_queue,
struct ef4_tx_buffer *buffer, size_t len)
{
if (len > EF4_TX_CB_SIZE)
return NULL;
return ef4_tx_get_copy_buffer(tx_queue, buffer);
}
static void ef4_dequeue_buffer(struct ef4_tx_queue *tx_queue,
struct ef4_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 & EF4_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 & EF4_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 ef4_tx_max_skb_descs(struct ef4_nic *efx)
{
/* This is probably too much since we don't have any TSO support;
* it's a left-over from when we had Software TSO. But it's safer
* to leave it as-is than try to determine a new bound.
*/
/* Header and payload descriptor for each output segment, plus
* one for every input fragment boundary within a segment
*/
unsigned int max_descs = EF4_TSO_MAX_SEGS * 2 + MAX_SKB_FRAGS;
/* Possibly one more per segment for the alignment workaround,
* or for option descriptors
*/
if (EF4_WORKAROUND_5391(efx))
max_descs += EF4_TSO_MAX_SEGS;
/* Possibly more for PCIe page boundaries within input fragments */
if (PAGE_SIZE > EF4_PAGE_SIZE)
max_descs += max_t(unsigned int, MAX_SKB_FRAGS,
DIV_ROUND_UP(GSO_LEGACY_MAX_SIZE,
EF4_PAGE_SIZE));
return max_descs;
}
static void ef4_tx_maybe_stop_queue(struct ef4_tx_queue *txq1)
{
/* We need to consider both queues that the net core sees as one */
struct ef4_tx_queue *txq2 = ef4_tx_queue_partner(txq1);
struct ef4_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 = READ_ONCE(txq1->read_count);
txq2->old_read_count = READ_ONCE(txq2->read_count);
fill_level = max(txq1->insert_count - txq1->old_read_count,
txq2->insert_count - txq2->old_read_count);
EF4_BUG_ON_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 ef4_enqueue_skb_copy(struct ef4_tx_queue *tx_queue,
struct sk_buff *skb)
{
unsigned int min_len = tx_queue->tx_min_size;
unsigned int copy_len = skb->len;
struct ef4_tx_buffer *buffer;
u8 *copy_buffer;
int rc;
EF4_BUG_ON_PARANOID(copy_len > EF4_TX_CB_SIZE);
buffer = ef4_tx_queue_get_insert_buffer(tx_queue);
copy_buffer = ef4_tx_get_copy_buffer(tx_queue, buffer);
if (unlikely(!copy_buffer))
return -ENOMEM;
rc = skb_copy_bits(skb, 0, copy_buffer, copy_len);
EF4_WARN_ON_PARANOID(rc);
if (unlikely(copy_len < min_len)) {
memset(copy_buffer + copy_len, 0, min_len - copy_len);
buffer->len = min_len;
} else {
buffer->len = copy_len;
}
buffer->skb = skb;
buffer->flags = EF4_TX_BUF_SKB;
++tx_queue->insert_count;
return rc;
}
static struct ef4_tx_buffer *ef4_tx_map_chunk(struct ef4_tx_queue *tx_queue,
dma_addr_t dma_addr,
size_t len)
{
const struct ef4_nic_type *nic_type = tx_queue->efx->type;
struct ef4_tx_buffer *buffer;
unsigned int dma_len;
/* Map the fragment taking account of NIC-dependent DMA limits. */
do {
buffer = ef4_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 = EF4_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 ef4_tx_map_data(struct ef4_tx_queue *tx_queue, struct sk_buff *skb)
{
struct ef4_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 = EF4_TX_BUF_MAP_SINGLE;
unmap_len = len;
unmap_addr = dma_addr;
if (unlikely(dma_mapping_error(dma_dev, dma_addr)))
return -EIO;
/* Add descriptors for each fragment. */
do {
struct ef4_tx_buffer *buffer;
skb_frag_t *fragment;
buffer = ef4_tx_map_chunk(tx_queue, dma_addr, len);
/* The final descriptor for a fragment is responsible for
* unmapping the whole fragment.
*/
buffer->flags = EF4_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 = EF4_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 ef4_enqueue_unwind(struct ef4_tx_queue *tx_queue)
{
struct ef4_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 = __ef4_tx_queue_get_insert_buffer(tx_queue);
ef4_dequeue_buffer(tx_queue, buffer, NULL, NULL);
}
}
/*
* 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 ef4_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 ef4_enqueue_skb(struct ef4_tx_queue *tx_queue, struct sk_buff *skb)
{
bool data_mapped = false;
unsigned int skb_len;
skb_len = skb->len;
EF4_WARN_ON_PARANOID(skb_is_gso(skb));
if (skb_len < tx_queue->tx_min_size ||
(skb->data_len && skb_len <= EF4_TX_CB_SIZE)) {
/* Pad short packets or coalesce short fragmented packets. */
if (ef4_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 && (ef4_tx_map_data(tx_queue, skb)))
goto err;
/* Update BQL */
netdev_tx_sent_queue(tx_queue->core_txq, skb_len);
/* Pass off to hardware */
if (!netdev_xmit_more() || netif_xmit_stopped(tx_queue->core_txq)) {
struct ef4_tx_queue *txq2 = ef4_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)
ef4_nic_push_buffers(txq2);
ef4_nic_push_buffers(tx_queue);
} else {
tx_queue->xmit_more_available = netdev_xmit_more();
}
tx_queue->tx_packets++;
ef4_tx_maybe_stop_queue(tx_queue);
return NETDEV_TX_OK;
err:
ef4_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 ef4_dequeue_buffers(struct ef4_tx_queue *tx_queue,
unsigned int index,
unsigned int *pkts_compl,
unsigned int *bytes_compl)
{
struct ef4_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 ef4_tx_buffer *buffer = &tx_queue->buffer[read_ptr];
if (!(buffer->flags & EF4_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);
ef4_schedule_reset(efx, RESET_TYPE_TX_SKIP);
return;
}
ef4_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 ef4_hard_start_xmit(struct sk_buff *skb,
struct net_device *net_dev)
{
struct ef4_nic *efx = netdev_priv(net_dev);
struct ef4_tx_queue *tx_queue;
unsigned index, type;
EF4_WARN_ON_PARANOID(!netif_device_present(net_dev));
index = skb_get_queue_mapping(skb);
type = skb->ip_summed == CHECKSUM_PARTIAL ? EF4_TXQ_TYPE_OFFLOAD : 0;
if (index >= efx->n_tx_channels) {
index -= efx->n_tx_channels;
type |= EF4_TXQ_TYPE_HIGHPRI;
}
tx_queue = ef4_get_tx_queue(efx, index, type);
return ef4_enqueue_skb(tx_queue, skb);
}
void ef4_init_tx_queue_core_txq(struct ef4_tx_queue *tx_queue)
{
struct ef4_nic *efx = tx_queue->efx;
/* Must be inverse of queue lookup in ef4_hard_start_xmit() */
tx_queue->core_txq =
netdev_get_tx_queue(efx->net_dev,
tx_queue->queue / EF4_TXQ_TYPES +
((tx_queue->queue & EF4_TXQ_TYPE_HIGHPRI) ?
efx->n_tx_channels : 0));
}
int ef4_setup_tc(struct net_device *net_dev, enum tc_setup_type type,
void *type_data)
{
struct ef4_nic *efx = netdev_priv(net_dev);
struct tc_mqprio_qopt *mqprio = type_data;
struct ef4_channel *channel;
struct ef4_tx_queue *tx_queue;
unsigned tc, num_tc;
int rc;
if (type != TC_SETUP_QDISC_MQPRIO)
return -EOPNOTSUPP;
num_tc = mqprio->num_tc;
if (ef4_nic_rev(efx) < EF4_REV_FALCON_B0 || num_tc > EF4_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 */
ef4_for_each_channel(channel, efx) {
ef4_for_each_possible_channel_tx_queue(tx_queue,
channel) {
if (!(tx_queue->queue & EF4_TXQ_TYPE_HIGHPRI))
continue;
if (!tx_queue->buffer) {
rc = ef4_probe_tx_queue(tx_queue);
if (rc)
return rc;
}
if (!tx_queue->initialised)
ef4_init_tx_queue(tx_queue);
ef4_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 ef4_fini_channels().
*/
net_dev->num_tc = num_tc;
return 0;
}
void ef4_xmit_done(struct ef4_tx_queue *tx_queue, unsigned int index)
{
unsigned fill_level;
struct ef4_nic *efx = tx_queue->efx;
struct ef4_tx_queue *txq2;
unsigned int pkts_compl = 0, bytes_compl = 0;
EF4_BUG_ON_PARANOID(index > tx_queue->ptr_mask);
ef4_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
* ef4_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 = ef4_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 | EF4_EMPTY_COUNT_VALID;
}
}
}
static unsigned int ef4_tx_cb_page_count(struct ef4_tx_queue *tx_queue)
{
return DIV_ROUND_UP(tx_queue->ptr_mask + 1, PAGE_SIZE >> EF4_TX_CB_ORDER);
}
int ef4_probe_tx_queue(struct ef4_tx_queue *tx_queue)
{
struct ef4_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), EF4_MIN_DMAQ_SIZE);
EF4_BUG_ON_PARANOID(entries > EF4_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(ef4_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 = ef4_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 ef4_init_tx_queue(struct ef4_tx_queue *tx_queue)
{
struct ef4_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->old_write_count = 0;
tx_queue->read_count = 0;
tx_queue->old_read_count = 0;
tx_queue->empty_read_count = 0 | EF4_EMPTY_COUNT_VALID;
tx_queue->xmit_more_available = false;
/* Some older hardware requires Tx writes larger than 32. */
tx_queue->tx_min_size = EF4_WORKAROUND_15592(efx) ? 33 : 0;
/* Set up TX descriptor ring */
ef4_nic_init_tx(tx_queue);
tx_queue->initialised = true;
}
void ef4_fini_tx_queue(struct ef4_tx_queue *tx_queue)
{
struct ef4_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];
ef4_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 ef4_remove_tx_queue(struct ef4_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);
ef4_nic_remove_tx(tx_queue);
if (tx_queue->cb_page) {
for (i = 0; i < ef4_tx_cb_page_count(tx_queue); i++)
ef4_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;
}