linux/drivers/net/sfc/rx.c

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/****************************************************************************
* Driver for Solarflare Solarstorm network controllers and boards
* Copyright 2005-2006 Fen Systems Ltd.
* Copyright 2005-2009 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 "efx.h"
#include "nic.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_AUTO;
#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;
}
/**
* 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);
dma-mapping: add the device argument to dma_mapping_error() Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:44:49 +00:00
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);
dma-mapping: add the device argument to dma_mapping_error() Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:44:49 +00:00
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 > EFX_RXQ_SIZE);
/* 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 > EFX_RXQ_SIZE);
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 & EFX_RXQ_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. */
efx_nic_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,
bool checksummed)
{
struct napi_struct *napi = &channel->napi_str;
gro_result_t gro_result;
/* Pass the skb/page into the LRO engine */
if (rx_buf->page) {
struct page *page = rx_buf->page;
struct sk_buff *skb;
EFX_BUG_ON_PARANOID(rx_buf->skb);
rx_buf->page = NULL;
skb = napi_get_frags(napi);
if (!skb) {
put_page(page);
return;
}
skb_shinfo(skb)->frags[0].page = page;
skb_shinfo(skb)->frags[0].page_offset =
efx_rx_buf_offset(rx_buf);
skb_shinfo(skb)->frags[0].size = rx_buf->len;
skb_shinfo(skb)->nr_frags = 1;
skb->len = rx_buf->len;
skb->data_len = rx_buf->len;
skb->truesize += rx_buf->len;
skb->ip_summed =
checksummed ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
skb_record_rx_queue(skb, channel->channel);
gro_result = napi_gro_frags(napi);
} else {
struct sk_buff *skb = rx_buf->skb;
EFX_BUG_ON_PARANOID(!skb);
EFX_BUG_ON_PARANOID(!checksummed);
rx_buf->skb = NULL;
gro_result = napi_gro_receive(napi, skb);
}
if (gro_result == GRO_NORMAL) {
channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
} else if (gro_result != GRO_DROP) {
channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;
channel->irq_mod_score += 2;
}
}
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;
/* 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);
return;
}
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);
skb_record_rx_queue(rx_buf->skb, channel->channel);
}
if (likely(checksummed || rx_buf->page)) {
efx_rx_packet_lro(channel, rx_buf, checksummed);
return;
}
/* We now own the SKB */
skb = rx_buf->skb;
rx_buf->skb = NULL;
EFX_BUG_ON_PARANOID(!skb);
/* Set the SKB flags */
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;
}
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_GRO)) {
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_RXQ_SIZE * sizeof(*rx_queue->buffer);
rx_queue->buffer = kzalloc(rxq_size, GFP_KERNEL);
if (!rx_queue->buffer)
return -ENOMEM;
rc = efx_nic_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)
{
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_RXQ_SIZE - 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 */
efx_nic_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);
efx_nic_fini_rx(rx_queue);
/* Release RX buffers NB start at index 0 not current HW ptr */
if (rx_queue->buffer) {
for (i = 0; i <= EFX_RXQ_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);
efx_nic_remove_rx(rx_queue);
kfree(rx_queue->buffer);
rx_queue->buffer = NULL;
}
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 (%)");