linux/drivers/net/sfc/rx.c
David S. Miller babcda74e9 drivers/net: Kill now superfluous ->last_rx stores.
The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.

Drivers need not do it any more.

Some cases had to be skipped over because the drivers
were making use of the ->last_rx value themselves.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03 21:11:17 -08:00

880 lines
25 KiB
C

/****************************************************************************
* Driver for Solarflare Solarstorm network controllers and boards
* Copyright 2005-2006 Fen Systems Ltd.
* Copyright 2005-2008 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/socket.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <net/ip.h>
#include <net/checksum.h>
#include "net_driver.h"
#include "rx.h"
#include "efx.h"
#include "falcon.h"
#include "selftest.h"
#include "workarounds.h"
/* Number of RX descriptors pushed at once. */
#define EFX_RX_BATCH 8
/* Size of buffer allocated for skb header area. */
#define EFX_SKB_HEADERS 64u
/*
* rx_alloc_method - RX buffer allocation method
*
* This driver supports two methods for allocating and using RX buffers:
* each RX buffer may be backed by an skb or by an order-n page.
*
* When LRO is in use then the second method has a lower overhead,
* since we don't have to allocate then free skbs on reassembled frames.
*
* Values:
* - RX_ALLOC_METHOD_AUTO = 0
* - RX_ALLOC_METHOD_SKB = 1
* - RX_ALLOC_METHOD_PAGE = 2
*
* The heuristic for %RX_ALLOC_METHOD_AUTO is a simple hysteresis count
* controlled by the parameters below.
*
* - Since pushing and popping descriptors are separated by the rx_queue
* size, so the watermarks should be ~rxd_size.
* - The performance win by using page-based allocation for LRO is less
* than the performance hit of using page-based allocation of non-LRO,
* so the watermarks should reflect this.
*
* Per channel we maintain a single variable, updated by each channel:
*
* rx_alloc_level += (lro_performed ? RX_ALLOC_FACTOR_LRO :
* RX_ALLOC_FACTOR_SKB)
* Per NAPI poll interval, we constrain rx_alloc_level to 0..MAX (which
* limits the hysteresis), and update the allocation strategy:
*
* rx_alloc_method = (rx_alloc_level > RX_ALLOC_LEVEL_LRO ?
* RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB)
*/
static int rx_alloc_method = RX_ALLOC_METHOD_PAGE;
#define RX_ALLOC_LEVEL_LRO 0x2000
#define RX_ALLOC_LEVEL_MAX 0x3000
#define RX_ALLOC_FACTOR_LRO 1
#define RX_ALLOC_FACTOR_SKB (-2)
/* This is the percentage fill level below which new RX descriptors
* will be added to the RX descriptor ring.
*/
static unsigned int rx_refill_threshold = 90;
/* This is the percentage fill level to which an RX queue will be refilled
* when the "RX refill threshold" is reached.
*/
static unsigned int rx_refill_limit = 95;
/*
* RX maximum head room required.
*
* This must be at least 1 to prevent overflow and at least 2 to allow
* pipelined receives.
*/
#define EFX_RXD_HEAD_ROOM 2
static inline unsigned int efx_rx_buf_offset(struct efx_rx_buffer *buf)
{
/* Offset is always within one page, so we don't need to consider
* the page order.
*/
return (__force unsigned long) buf->data & (PAGE_SIZE - 1);
}
static inline unsigned int efx_rx_buf_size(struct efx_nic *efx)
{
return PAGE_SIZE << efx->rx_buffer_order;
}
/**************************************************************************
*
* Linux generic LRO handling
*
**************************************************************************
*/
static int efx_lro_get_skb_hdr(struct sk_buff *skb, void **ip_hdr,
void **tcpudp_hdr, u64 *hdr_flags, void *priv)
{
struct efx_channel *channel = priv;
struct iphdr *iph;
struct tcphdr *th;
iph = (struct iphdr *)skb->data;
if (skb->protocol != htons(ETH_P_IP) || iph->protocol != IPPROTO_TCP)
goto fail;
th = (struct tcphdr *)(skb->data + iph->ihl * 4);
*tcpudp_hdr = th;
*ip_hdr = iph;
*hdr_flags = LRO_IPV4 | LRO_TCP;
channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;
return 0;
fail:
channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
return -1;
}
static int efx_get_frag_hdr(struct skb_frag_struct *frag, void **mac_hdr,
void **ip_hdr, void **tcpudp_hdr, u64 *hdr_flags,
void *priv)
{
struct efx_channel *channel = priv;
struct ethhdr *eh;
struct iphdr *iph;
/* We support EtherII and VLAN encapsulated IPv4 */
eh = page_address(frag->page) + frag->page_offset;
*mac_hdr = eh;
if (eh->h_proto == htons(ETH_P_IP)) {
iph = (struct iphdr *)(eh + 1);
} else {
struct vlan_ethhdr *veh = (struct vlan_ethhdr *)eh;
if (veh->h_vlan_encapsulated_proto != htons(ETH_P_IP))
goto fail;
iph = (struct iphdr *)(veh + 1);
}
*ip_hdr = iph;
/* We can only do LRO over TCP */
if (iph->protocol != IPPROTO_TCP)
goto fail;
*hdr_flags = LRO_IPV4 | LRO_TCP;
*tcpudp_hdr = (struct tcphdr *)((u8 *) iph + iph->ihl * 4);
channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;
return 0;
fail:
channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
return -1;
}
int efx_lro_init(struct net_lro_mgr *lro_mgr, struct efx_nic *efx)
{
size_t s = sizeof(struct net_lro_desc) * EFX_MAX_LRO_DESCRIPTORS;
struct net_lro_desc *lro_arr;
/* Allocate the LRO descriptors structure */
lro_arr = kzalloc(s, GFP_KERNEL);
if (lro_arr == NULL)
return -ENOMEM;
lro_mgr->lro_arr = lro_arr;
lro_mgr->max_desc = EFX_MAX_LRO_DESCRIPTORS;
lro_mgr->max_aggr = EFX_MAX_LRO_AGGR;
lro_mgr->frag_align_pad = EFX_PAGE_SKB_ALIGN;
lro_mgr->get_skb_header = efx_lro_get_skb_hdr;
lro_mgr->get_frag_header = efx_get_frag_hdr;
lro_mgr->dev = efx->net_dev;
lro_mgr->features = LRO_F_NAPI;
/* We can pass packets up with the checksum intact */
lro_mgr->ip_summed = CHECKSUM_UNNECESSARY;
lro_mgr->ip_summed_aggr = CHECKSUM_UNNECESSARY;
return 0;
}
void efx_lro_fini(struct net_lro_mgr *lro_mgr)
{
kfree(lro_mgr->lro_arr);
lro_mgr->lro_arr = NULL;
}
/**
* efx_init_rx_buffer_skb - create new RX buffer using skb-based allocation
*
* @rx_queue: Efx RX queue
* @rx_buf: RX buffer structure to populate
*
* This allocates memory for a new receive buffer, maps it for DMA,
* and populates a struct efx_rx_buffer with the relevant
* information. Return a negative error code or 0 on success.
*/
static int efx_init_rx_buffer_skb(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf)
{
struct efx_nic *efx = rx_queue->efx;
struct net_device *net_dev = efx->net_dev;
int skb_len = efx->rx_buffer_len;
rx_buf->skb = netdev_alloc_skb(net_dev, skb_len);
if (unlikely(!rx_buf->skb))
return -ENOMEM;
/* Adjust the SKB for padding and checksum */
skb_reserve(rx_buf->skb, NET_IP_ALIGN);
rx_buf->len = skb_len - NET_IP_ALIGN;
rx_buf->data = (char *)rx_buf->skb->data;
rx_buf->skb->ip_summed = CHECKSUM_UNNECESSARY;
rx_buf->dma_addr = pci_map_single(efx->pci_dev,
rx_buf->data, rx_buf->len,
PCI_DMA_FROMDEVICE);
if (unlikely(pci_dma_mapping_error(efx->pci_dev, rx_buf->dma_addr))) {
dev_kfree_skb_any(rx_buf->skb);
rx_buf->skb = NULL;
return -EIO;
}
return 0;
}
/**
* efx_init_rx_buffer_page - create new RX buffer using page-based allocation
*
* @rx_queue: Efx RX queue
* @rx_buf: RX buffer structure to populate
*
* This allocates memory for a new receive buffer, maps it for DMA,
* and populates a struct efx_rx_buffer with the relevant
* information. Return a negative error code or 0 on success.
*/
static int efx_init_rx_buffer_page(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf)
{
struct efx_nic *efx = rx_queue->efx;
int bytes, space, offset;
bytes = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
/* If there is space left in the previously allocated page,
* then use it. Otherwise allocate a new one */
rx_buf->page = rx_queue->buf_page;
if (rx_buf->page == NULL) {
dma_addr_t dma_addr;
rx_buf->page = alloc_pages(__GFP_COLD | __GFP_COMP | GFP_ATOMIC,
efx->rx_buffer_order);
if (unlikely(rx_buf->page == NULL))
return -ENOMEM;
dma_addr = pci_map_page(efx->pci_dev, rx_buf->page,
0, efx_rx_buf_size(efx),
PCI_DMA_FROMDEVICE);
if (unlikely(pci_dma_mapping_error(efx->pci_dev, dma_addr))) {
__free_pages(rx_buf->page, efx->rx_buffer_order);
rx_buf->page = NULL;
return -EIO;
}
rx_queue->buf_page = rx_buf->page;
rx_queue->buf_dma_addr = dma_addr;
rx_queue->buf_data = (page_address(rx_buf->page) +
EFX_PAGE_IP_ALIGN);
}
rx_buf->len = bytes;
rx_buf->data = rx_queue->buf_data;
offset = efx_rx_buf_offset(rx_buf);
rx_buf->dma_addr = rx_queue->buf_dma_addr + offset;
/* Try to pack multiple buffers per page */
if (efx->rx_buffer_order == 0) {
/* The next buffer starts on the next 512 byte boundary */
rx_queue->buf_data += ((bytes + 0x1ff) & ~0x1ff);
offset += ((bytes + 0x1ff) & ~0x1ff);
space = efx_rx_buf_size(efx) - offset;
if (space >= bytes) {
/* Refs dropped on kernel releasing each skb */
get_page(rx_queue->buf_page);
goto out;
}
}
/* This is the final RX buffer for this page, so mark it for
* unmapping */
rx_queue->buf_page = NULL;
rx_buf->unmap_addr = rx_queue->buf_dma_addr;
out:
return 0;
}
/* This allocates memory for a new receive buffer, maps it for DMA,
* and populates a struct efx_rx_buffer with the relevant
* information.
*/
static int efx_init_rx_buffer(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *new_rx_buf)
{
int rc = 0;
if (rx_queue->channel->rx_alloc_push_pages) {
new_rx_buf->skb = NULL;
rc = efx_init_rx_buffer_page(rx_queue, new_rx_buf);
rx_queue->alloc_page_count++;
} else {
new_rx_buf->page = NULL;
rc = efx_init_rx_buffer_skb(rx_queue, new_rx_buf);
rx_queue->alloc_skb_count++;
}
if (unlikely(rc < 0))
EFX_LOG_RL(rx_queue->efx, "%s RXQ[%d] =%d\n", __func__,
rx_queue->queue, rc);
return rc;
}
static void efx_unmap_rx_buffer(struct efx_nic *efx,
struct efx_rx_buffer *rx_buf)
{
if (rx_buf->page) {
EFX_BUG_ON_PARANOID(rx_buf->skb);
if (rx_buf->unmap_addr) {
pci_unmap_page(efx->pci_dev, rx_buf->unmap_addr,
efx_rx_buf_size(efx),
PCI_DMA_FROMDEVICE);
rx_buf->unmap_addr = 0;
}
} else if (likely(rx_buf->skb)) {
pci_unmap_single(efx->pci_dev, rx_buf->dma_addr,
rx_buf->len, PCI_DMA_FROMDEVICE);
}
}
static void efx_free_rx_buffer(struct efx_nic *efx,
struct efx_rx_buffer *rx_buf)
{
if (rx_buf->page) {
__free_pages(rx_buf->page, efx->rx_buffer_order);
rx_buf->page = NULL;
} else if (likely(rx_buf->skb)) {
dev_kfree_skb_any(rx_buf->skb);
rx_buf->skb = NULL;
}
}
static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf)
{
efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
efx_free_rx_buffer(rx_queue->efx, rx_buf);
}
/**
* efx_fast_push_rx_descriptors - push new RX descriptors quickly
* @rx_queue: RX descriptor queue
* @retry: Recheck the fill level
* This will aim to fill the RX descriptor queue up to
* @rx_queue->@fast_fill_limit. If there is insufficient atomic
* memory to do so, the caller should retry.
*/
static int __efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue,
int retry)
{
struct efx_rx_buffer *rx_buf;
unsigned fill_level, index;
int i, space, rc = 0;
/* Calculate current fill level. Do this outside the lock,
* because most of the time we'll end up not wanting to do the
* fill anyway.
*/
fill_level = (rx_queue->added_count - rx_queue->removed_count);
EFX_BUG_ON_PARANOID(fill_level >
rx_queue->efx->type->rxd_ring_mask + 1);
/* Don't fill if we don't need to */
if (fill_level >= rx_queue->fast_fill_trigger)
return 0;
/* Record minimum fill level */
if (unlikely(fill_level < rx_queue->min_fill)) {
if (fill_level)
rx_queue->min_fill = fill_level;
}
/* Acquire RX add lock. If this lock is contended, then a fast
* fill must already be in progress (e.g. in the refill
* tasklet), so we don't need to do anything
*/
if (!spin_trylock_bh(&rx_queue->add_lock))
return -1;
retry:
/* Recalculate current fill level now that we have the lock */
fill_level = (rx_queue->added_count - rx_queue->removed_count);
EFX_BUG_ON_PARANOID(fill_level >
rx_queue->efx->type->rxd_ring_mask + 1);
space = rx_queue->fast_fill_limit - fill_level;
if (space < EFX_RX_BATCH)
goto out_unlock;
EFX_TRACE(rx_queue->efx, "RX queue %d fast-filling descriptor ring from"
" level %d to level %d using %s allocation\n",
rx_queue->queue, fill_level, rx_queue->fast_fill_limit,
rx_queue->channel->rx_alloc_push_pages ? "page" : "skb");
do {
for (i = 0; i < EFX_RX_BATCH; ++i) {
index = (rx_queue->added_count &
rx_queue->efx->type->rxd_ring_mask);
rx_buf = efx_rx_buffer(rx_queue, index);
rc = efx_init_rx_buffer(rx_queue, rx_buf);
if (unlikely(rc))
goto out;
++rx_queue->added_count;
}
} while ((space -= EFX_RX_BATCH) >= EFX_RX_BATCH);
EFX_TRACE(rx_queue->efx, "RX queue %d fast-filled descriptor ring "
"to level %d\n", rx_queue->queue,
rx_queue->added_count - rx_queue->removed_count);
out:
/* Send write pointer to card. */
falcon_notify_rx_desc(rx_queue);
/* If the fast fill is running inside from the refill tasklet, then
* for SMP systems it may be running on a different CPU to
* RX event processing, which means that the fill level may now be
* out of date. */
if (unlikely(retry && (rc == 0)))
goto retry;
out_unlock:
spin_unlock_bh(&rx_queue->add_lock);
return rc;
}
/**
* efx_fast_push_rx_descriptors - push new RX descriptors quickly
* @rx_queue: RX descriptor queue
*
* This will aim to fill the RX descriptor queue up to
* @rx_queue->@fast_fill_limit. If there is insufficient memory to do so,
* it will schedule a work item to immediately continue the fast fill
*/
void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue)
{
int rc;
rc = __efx_fast_push_rx_descriptors(rx_queue, 0);
if (unlikely(rc)) {
/* Schedule the work item to run immediately. The hope is
* that work is immediately pending to free some memory
* (e.g. an RX event or TX completion)
*/
efx_schedule_slow_fill(rx_queue, 0);
}
}
void efx_rx_work(struct work_struct *data)
{
struct efx_rx_queue *rx_queue;
int rc;
rx_queue = container_of(data, struct efx_rx_queue, work.work);
if (unlikely(!rx_queue->channel->enabled))
return;
EFX_TRACE(rx_queue->efx, "RX queue %d worker thread executing on CPU "
"%d\n", rx_queue->queue, raw_smp_processor_id());
++rx_queue->slow_fill_count;
/* Push new RX descriptors, allowing at least 1 jiffy for
* the kernel to free some more memory. */
rc = __efx_fast_push_rx_descriptors(rx_queue, 1);
if (rc)
efx_schedule_slow_fill(rx_queue, 1);
}
static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf,
int len, bool *discard,
bool *leak_packet)
{
struct efx_nic *efx = rx_queue->efx;
unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
if (likely(len <= max_len))
return;
/* The packet must be discarded, but this is only a fatal error
* if the caller indicated it was
*/
*discard = true;
if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
EFX_ERR_RL(efx, " RX queue %d seriously overlength "
"RX event (0x%x > 0x%x+0x%x). Leaking\n",
rx_queue->queue, len, max_len,
efx->type->rx_buffer_padding);
/* If this buffer was skb-allocated, then the meta
* data at the end of the skb will be trashed. So
* we have no choice but to leak the fragment.
*/
*leak_packet = (rx_buf->skb != NULL);
efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
} else {
EFX_ERR_RL(efx, " RX queue %d overlength RX event "
"(0x%x > 0x%x)\n", rx_queue->queue, len, max_len);
}
rx_queue->channel->n_rx_overlength++;
}
/* Pass a received packet up through the generic LRO stack
*
* Handles driverlink veto, and passes the fragment up via
* the appropriate LRO method
*/
static void efx_rx_packet_lro(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf)
{
struct net_lro_mgr *lro_mgr = &channel->lro_mgr;
void *priv = channel;
/* Pass the skb/page into the LRO engine */
if (rx_buf->page) {
struct skb_frag_struct frags;
frags.page = rx_buf->page;
frags.page_offset = efx_rx_buf_offset(rx_buf);
frags.size = rx_buf->len;
lro_receive_frags(lro_mgr, &frags, rx_buf->len,
rx_buf->len, priv, 0);
EFX_BUG_ON_PARANOID(rx_buf->skb);
rx_buf->page = NULL;
} else {
EFX_BUG_ON_PARANOID(!rx_buf->skb);
lro_receive_skb(lro_mgr, rx_buf->skb, priv);
rx_buf->skb = NULL;
}
}
/* Allocate and construct an SKB around a struct page.*/
static struct sk_buff *efx_rx_mk_skb(struct efx_rx_buffer *rx_buf,
struct efx_nic *efx,
int hdr_len)
{
struct sk_buff *skb;
/* Allocate an SKB to store the headers */
skb = netdev_alloc_skb(efx->net_dev, hdr_len + EFX_PAGE_SKB_ALIGN);
if (unlikely(skb == NULL)) {
EFX_ERR_RL(efx, "RX out of memory for skb\n");
return NULL;
}
EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags);
EFX_BUG_ON_PARANOID(rx_buf->len < hdr_len);
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb_reserve(skb, EFX_PAGE_SKB_ALIGN);
skb->len = rx_buf->len;
skb->truesize = rx_buf->len + sizeof(struct sk_buff);
memcpy(skb->data, rx_buf->data, hdr_len);
skb->tail += hdr_len;
/* Append the remaining page onto the frag list */
if (unlikely(rx_buf->len > hdr_len)) {
struct skb_frag_struct *frag = skb_shinfo(skb)->frags;
frag->page = rx_buf->page;
frag->page_offset = efx_rx_buf_offset(rx_buf) + hdr_len;
frag->size = skb->len - hdr_len;
skb_shinfo(skb)->nr_frags = 1;
skb->data_len = frag->size;
} else {
__free_pages(rx_buf->page, efx->rx_buffer_order);
skb->data_len = 0;
}
/* Ownership has transferred from the rx_buf to skb */
rx_buf->page = NULL;
/* Move past the ethernet header */
skb->protocol = eth_type_trans(skb, efx->net_dev);
return skb;
}
void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
unsigned int len, bool checksummed, bool discard)
{
struct efx_nic *efx = rx_queue->efx;
struct efx_rx_buffer *rx_buf;
bool leak_packet = false;
rx_buf = efx_rx_buffer(rx_queue, index);
EFX_BUG_ON_PARANOID(!rx_buf->data);
EFX_BUG_ON_PARANOID(rx_buf->skb && rx_buf->page);
EFX_BUG_ON_PARANOID(!(rx_buf->skb || rx_buf->page));
/* This allows the refill path to post another buffer.
* EFX_RXD_HEAD_ROOM ensures that the slot we are using
* isn't overwritten yet.
*/
rx_queue->removed_count++;
/* Validate the length encoded in the event vs the descriptor pushed */
efx_rx_packet__check_len(rx_queue, rx_buf, len,
&discard, &leak_packet);
EFX_TRACE(efx, "RX queue %d received id %x at %llx+%x %s%s\n",
rx_queue->queue, index,
(unsigned long long)rx_buf->dma_addr, len,
(checksummed ? " [SUMMED]" : ""),
(discard ? " [DISCARD]" : ""));
/* Discard packet, if instructed to do so */
if (unlikely(discard)) {
if (unlikely(leak_packet))
rx_queue->channel->n_skbuff_leaks++;
else
/* We haven't called efx_unmap_rx_buffer yet,
* so fini the entire rx_buffer here */
efx_fini_rx_buffer(rx_queue, rx_buf);
return;
}
/* Release card resources - assumes all RX buffers consumed in-order
* per RX queue
*/
efx_unmap_rx_buffer(efx, rx_buf);
/* Prefetch nice and early so data will (hopefully) be in cache by
* the time we look at it.
*/
prefetch(rx_buf->data);
/* Pipeline receives so that we give time for packet headers to be
* prefetched into cache.
*/
rx_buf->len = len;
if (rx_queue->channel->rx_pkt)
__efx_rx_packet(rx_queue->channel,
rx_queue->channel->rx_pkt,
rx_queue->channel->rx_pkt_csummed);
rx_queue->channel->rx_pkt = rx_buf;
rx_queue->channel->rx_pkt_csummed = checksummed;
}
/* Handle a received packet. Second half: Touches packet payload. */
void __efx_rx_packet(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf, bool checksummed)
{
struct efx_nic *efx = channel->efx;
struct sk_buff *skb;
bool lro = !!(efx->net_dev->features & NETIF_F_LRO);
/* If we're in loopback test, then pass the packet directly to the
* loopback layer, and free the rx_buf here
*/
if (unlikely(efx->loopback_selftest)) {
efx_loopback_rx_packet(efx, rx_buf->data, rx_buf->len);
efx_free_rx_buffer(efx, rx_buf);
goto done;
}
if (rx_buf->skb) {
prefetch(skb_shinfo(rx_buf->skb));
skb_put(rx_buf->skb, rx_buf->len);
/* Move past the ethernet header. rx_buf->data still points
* at the ethernet header */
rx_buf->skb->protocol = eth_type_trans(rx_buf->skb,
efx->net_dev);
}
/* Both our generic-LRO and SFC-SSR support skb and page based
* allocation, but neither support switching from one to the
* other on the fly. If we spot that the allocation mode has
* changed, then flush the LRO state.
*/
if (unlikely(channel->rx_alloc_pop_pages != (rx_buf->page != NULL))) {
efx_flush_lro(channel);
channel->rx_alloc_pop_pages = (rx_buf->page != NULL);
}
if (likely(checksummed && lro)) {
efx_rx_packet_lro(channel, rx_buf);
goto done;
}
/* Form an skb if required */
if (rx_buf->page) {
int hdr_len = min(rx_buf->len, EFX_SKB_HEADERS);
skb = efx_rx_mk_skb(rx_buf, efx, hdr_len);
if (unlikely(skb == NULL)) {
efx_free_rx_buffer(efx, rx_buf);
goto done;
}
} else {
/* We now own the SKB */
skb = rx_buf->skb;
rx_buf->skb = NULL;
}
EFX_BUG_ON_PARANOID(rx_buf->page);
EFX_BUG_ON_PARANOID(rx_buf->skb);
EFX_BUG_ON_PARANOID(!skb);
/* Set the SKB flags */
if (unlikely(!checksummed || !efx->rx_checksum_enabled))
skb->ip_summed = CHECKSUM_NONE;
/* Pass the packet up */
netif_receive_skb(skb);
/* Update allocation strategy method */
channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
done:
;
}
void efx_rx_strategy(struct efx_channel *channel)
{
enum efx_rx_alloc_method method = rx_alloc_method;
/* Only makes sense to use page based allocation if LRO is enabled */
if (!(channel->efx->net_dev->features & NETIF_F_LRO)) {
method = RX_ALLOC_METHOD_SKB;
} else if (method == RX_ALLOC_METHOD_AUTO) {
/* Constrain the rx_alloc_level */
if (channel->rx_alloc_level < 0)
channel->rx_alloc_level = 0;
else if (channel->rx_alloc_level > RX_ALLOC_LEVEL_MAX)
channel->rx_alloc_level = RX_ALLOC_LEVEL_MAX;
/* Decide on the allocation method */
method = ((channel->rx_alloc_level > RX_ALLOC_LEVEL_LRO) ?
RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB);
}
/* Push the option */
channel->rx_alloc_push_pages = (method == RX_ALLOC_METHOD_PAGE);
}
int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
{
struct efx_nic *efx = rx_queue->efx;
unsigned int rxq_size;
int rc;
EFX_LOG(efx, "creating RX queue %d\n", rx_queue->queue);
/* Allocate RX buffers */
rxq_size = (efx->type->rxd_ring_mask + 1) * sizeof(*rx_queue->buffer);
rx_queue->buffer = kzalloc(rxq_size, GFP_KERNEL);
if (!rx_queue->buffer)
return -ENOMEM;
rc = falcon_probe_rx(rx_queue);
if (rc) {
kfree(rx_queue->buffer);
rx_queue->buffer = NULL;
}
return rc;
}
void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
{
struct efx_nic *efx = rx_queue->efx;
unsigned int max_fill, trigger, limit;
EFX_LOG(rx_queue->efx, "initialising RX queue %d\n", rx_queue->queue);
/* Initialise ptr fields */
rx_queue->added_count = 0;
rx_queue->notified_count = 0;
rx_queue->removed_count = 0;
rx_queue->min_fill = -1U;
rx_queue->min_overfill = -1U;
/* Initialise limit fields */
max_fill = efx->type->rxd_ring_mask + 1 - EFX_RXD_HEAD_ROOM;
trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
limit = max_fill * min(rx_refill_limit, 100U) / 100U;
rx_queue->max_fill = max_fill;
rx_queue->fast_fill_trigger = trigger;
rx_queue->fast_fill_limit = limit;
/* Set up RX descriptor ring */
falcon_init_rx(rx_queue);
}
void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
{
int i;
struct efx_rx_buffer *rx_buf;
EFX_LOG(rx_queue->efx, "shutting down RX queue %d\n", rx_queue->queue);
falcon_fini_rx(rx_queue);
/* Release RX buffers NB start at index 0 not current HW ptr */
if (rx_queue->buffer) {
for (i = 0; i <= rx_queue->efx->type->rxd_ring_mask; i++) {
rx_buf = efx_rx_buffer(rx_queue, i);
efx_fini_rx_buffer(rx_queue, rx_buf);
}
}
/* For a page that is part-way through splitting into RX buffers */
if (rx_queue->buf_page != NULL) {
pci_unmap_page(rx_queue->efx->pci_dev, rx_queue->buf_dma_addr,
efx_rx_buf_size(rx_queue->efx),
PCI_DMA_FROMDEVICE);
__free_pages(rx_queue->buf_page,
rx_queue->efx->rx_buffer_order);
rx_queue->buf_page = NULL;
}
}
void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
{
EFX_LOG(rx_queue->efx, "destroying RX queue %d\n", rx_queue->queue);
falcon_remove_rx(rx_queue);
kfree(rx_queue->buffer);
rx_queue->buffer = NULL;
}
void efx_flush_lro(struct efx_channel *channel)
{
lro_flush_all(&channel->lro_mgr);
}
module_param(rx_alloc_method, int, 0644);
MODULE_PARM_DESC(rx_alloc_method, "Allocation method used for RX buffers");
module_param(rx_refill_threshold, uint, 0444);
MODULE_PARM_DESC(rx_refill_threshold,
"RX descriptor ring fast/slow fill threshold (%)");