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Message-ID: <20080312012322.GD24160@solarflare.com>
Date: Wed, 12 Mar 2008 01:23:23 +0000
From: Ben Hutchings <bhutchings@...arflare.com>
To: netdev@...r.kernel.org
Cc: linux-net-drivers@...arflare.com, Jeff Garzik <jgarzik@...ox.com>,
David Miller <davem@...emloft.net>
Subject: [PATCH 2/8] New driver "sfc" for Solarstorm SFC4000 controller (try #8)
Signed-off-by: Ben Hutchings <bhutchings@...arflare.com>
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
new file mode 100644
index 0000000..cf74b5f
--- /dev/null
+++ b/drivers/net/sfc/rx.c
@@ -0,0 +1,875 @@
+/****************************************************************************
+ * 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 "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
+
+/* Macros for zero-order pages (potentially) containing multiple RX buffers */
+#define RX_DATA_OFFSET(_data) \
+ (((unsigned long) (_data)) & (PAGE_SIZE-1))
+#define RX_BUF_OFFSET(_rx_buf) \
+ RX_DATA_OFFSET((_rx_buf)->data)
+
+#define RX_PAGE_SIZE(_efx) \
+ (PAGE_SIZE * (1u << (_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 = (struct efx_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 = (struct efx_channel *)priv;
+ struct ethhdr *eh;
+ struct iphdr *iph;
+
+ /* We support EtherII and VLAN encapsulated IPv4 */
+ eh = (struct ethhdr *)(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 inline 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(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 inline 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, RX_PAGE_SIZE(efx),
+ PCI_DMA_FROMDEVICE);
+
+ if (unlikely(pci_dma_mapping_error(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 = ((char *) page_address(rx_buf->page) +
+ EFX_PAGE_IP_ALIGN);
+ }
+
+ offset = RX_DATA_OFFSET(rx_queue->buf_data);
+ rx_buf->len = bytes;
+ rx_buf->dma_addr = rx_queue->buf_dma_addr + offset;
+ rx_buf->data = rx_queue->buf_data;
+
+ /* 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 = RX_PAGE_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 inline 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 inline 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,
+ RX_PAGE_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 inline 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 inline 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 inline void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
+ struct efx_rx_buffer *rx_buf,
+ int len, int *discard,
+ int *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 = 1;
+
+ 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 inline 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 = 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 inline 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 = 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, int checksummed, int discard)
+{
+ struct efx_nic *efx = rx_queue->efx;
+ struct efx_rx_buffer *rx_buf;
+ int leak_packet = 0;
+
+ 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, int checksummed)
+{
+ struct efx_nic *efx = channel->efx;
+ struct sk_buff *skb;
+ int lro = efx->net_dev->features & NETIF_F_LRO;
+
+ 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;
+
+ /* fall-thru */
+done:
+ efx->net_dev->last_rx = jiffies;
+}
+
+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) {
+ rc = -ENOMEM;
+ goto fail1;
+ }
+
+ rc = falcon_probe_rx(rx_queue);
+ if (rc)
+ goto fail2;
+
+ return 0;
+
+ fail2:
+ kfree(rx_queue->buffer);
+ rx_queue->buffer = NULL;
+ fail1:
+ rx_queue->used = 0;
+
+ return rc;
+}
+
+int 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 */
+ return 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,
+ RX_PAGE_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;
+ rx_queue->used = 0;
+}
+
+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 (%)");
+
diff --git a/drivers/net/sfc/rx.h b/drivers/net/sfc/rx.h
new file mode 100644
index 0000000..f35e377
--- /dev/null
+++ b/drivers/net/sfc/rx.h
@@ -0,0 +1,29 @@
+/****************************************************************************
+ * Driver for Solarflare Solarstorm network controllers and boards
+ * Copyright 2006 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.
+ */
+
+#ifndef EFX_RX_H
+#define EFX_RX_H
+
+#include "net_driver.h"
+
+int efx_probe_rx_queue(struct efx_rx_queue *rx_queue);
+void efx_remove_rx_queue(struct efx_rx_queue *rx_queue);
+int efx_init_rx_queue(struct efx_rx_queue *rx_queue);
+void efx_fini_rx_queue(struct efx_rx_queue *rx_queue);
+
+int efx_lro_init(struct net_lro_mgr *lro_mgr, struct efx_nic *efx);
+void efx_lro_fini(struct net_lro_mgr *lro_mgr);
+void efx_flush_lro(struct efx_channel *channel);
+void efx_rx_strategy(struct efx_channel *channel);
+void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue);
+void efx_rx_work(struct work_struct *data);
+void __efx_rx_packet(struct efx_channel *channel,
+ struct efx_rx_buffer *rx_buf, int checksummed);
+
+#endif /* EFX_RX_H */
diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
new file mode 100644
index 0000000..7dc70a2
--- /dev/null
+++ b/drivers/net/sfc/tx.c
@@ -0,0 +1,465 @@
+/****************************************************************************
+ * 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/pci.h>
+#include <linux/tcp.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/highmem.h>
+#include "net_driver.h"
+#include "tx.h"
+#include "efx.h"
+#include "falcon.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_NETDEV_TX_THRESHOLD(_tx_queue) \
+ (_tx_queue->efx->type->txd_ring_mask / 2u)
+
+/* We want to be able to nest calls to netif_stop_queue(), since each
+ * channel can have an individual stop on the queue.
+ */
+void efx_stop_queue(struct efx_nic *efx)
+{
+ spin_lock_bh(&efx->netif_stop_lock);
+ EFX_TRACE(efx, "stop TX queue\n");
+
+ atomic_inc(&efx->netif_stop_count);
+ if (likely(efx->net_dev_registered))
+ netif_stop_queue(efx->net_dev);
+
+ spin_unlock_bh(&efx->netif_stop_lock);
+}
+
+/* Wake netif's TX queue
+ * We want to be able to nest calls to netif_stop_queue(), since each
+ * channel can have an individual stop on the queue.
+ */
+inline void efx_wake_queue(struct efx_nic *efx)
+{
+ local_bh_disable();
+ if (atomic_dec_and_lock(&efx->netif_stop_count,
+ &efx->netif_stop_lock)) {
+ EFX_TRACE(efx, "waking TX queue\n");
+ if (likely(efx->net_dev_registered))
+ netif_wake_queue(efx->net_dev);
+ spin_unlock(&efx->netif_stop_lock);
+ }
+ local_bh_enable();
+}
+
+/*
+ * 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.
+ *
+ * Returns NETDEV_TX_OK or NETDEV_TX_BUSY
+ * You must hold netif_tx_lock() to call this function.
+ */
+static inline int efx_enqueue_skb(struct efx_tx_queue *tx_queue,
+ const 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, misalign;
+ dma_addr_t dma_addr, unmap_addr = 0;
+ unsigned int dma_len;
+ unsigned unmap_single;
+ int q_space, i = 0;
+ int rc = NETDEV_TX_OK;
+
+ EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count);
+
+ /* Get size of the initial fragment */
+ len = skb_headlen(skb);
+
+ fill_level = tx_queue->insert_count - tx_queue->old_read_count;
+ q_space = efx->type->txd_ring_mask - 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 = 1;
+ dma_addr = pci_map_single(pci_dev, skb->data, len, PCI_DMA_TODEVICE);
+
+ /* Process all fragments */
+ while (1) {
+ if (unlikely(pci_dma_mapping_error(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.
+ */
+ ++tx_queue->stopped;
+ /* This memory barrier protects the
+ * change of stopped from the access
+ * of read_count. */
+ smp_mb();
+ tx_queue->old_read_count =
+ *(volatile unsigned *)
+ &tx_queue->read_count;
+ fill_level = (tx_queue->insert_count
+ - tx_queue->old_read_count);
+ q_space = (efx->type->txd_ring_mask - 1 -
+ fill_level);
+ if (unlikely(q_space-- <= 0))
+ goto stop;
+ smp_mb();
+ --tx_queue->stopped;
+ }
+
+ insert_ptr = (tx_queue->insert_count &
+ efx->type->txd_ring_mask);
+ buffer = &tx_queue->buffer[insert_ptr];
+ EFX_BUG_ON_PARANOID(buffer->skb);
+ EFX_BUG_ON_PARANOID(buffer->len);
+ EFX_BUG_ON_PARANOID(buffer->continuation != 1);
+ EFX_BUG_ON_PARANOID(buffer->unmap_len);
+
+ dma_len = (((~dma_addr) & efx->type->tx_dma_mask) + 1);
+ if (likely(dma_len > len))
+ dma_len = len;
+
+ misalign = (unsigned)dma_addr & efx->type->bug5391_mask;
+ if (misalign && dma_len + misalign > 512)
+ dma_len = 512 - misalign;
+
+ /* 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_addr = unmap_addr;
+ 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 = 0;
+ 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 = 0;
+
+ /* Pass off to hardware */
+ falcon_push_buffers(tx_queue);
+
+ return NETDEV_TX_OK;
+
+ pci_err:
+ EFX_ERR_RL(efx, " 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((struct sk_buff *)skb);
+ goto unwind;
+
+ stop:
+ rc = NETDEV_TX_BUSY;
+
+ if (tx_queue->stopped == 1)
+ efx_stop_queue(efx);
+
+ 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 & efx->type->txd_ring_mask;
+ buffer = &tx_queue->buffer[insert_ptr];
+ if (buffer->unmap_len) {
+ if (buffer->unmap_single)
+ pci_unmap_single(pci_dev, buffer->unmap_addr,
+ buffer->unmap_len,
+ PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(pci_dev, buffer->unmap_addr,
+ buffer->unmap_len,
+ PCI_DMA_TODEVICE);
+ }
+ buffer->unmap_len = 0;
+ buffer->len = 0;
+ }
+
+ /* Free the fragment we were mid-way through pushing */
+ if (unmap_len)
+ 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 inline void efx_dequeue_buffers(struct efx_tx_queue *tx_queue,
+ unsigned int index)
+{
+ struct pci_dev *pci_dev = tx_queue->efx->pci_dev;
+ struct efx_tx_buffer *buffer;
+ unsigned int stop_index, read_ptr;
+
+ /* Calculate the stopping point. Doing the check this way
+ * avoids wrongly completing every buffer in the ring if we
+ * get called twice with the same index. (Hardware should
+ * never do this, since it can't complete that many buffers in
+ * one go.)
+ */
+ stop_index = (index + 1) & tx_queue->efx->type->txd_ring_mask;
+ read_ptr = tx_queue->read_count & tx_queue->efx->type->txd_ring_mask;
+
+ while (read_ptr != stop_index) {
+ buffer = &tx_queue->buffer[read_ptr];
+ if (unlikely(buffer->len == 0)) {
+ EFX_ERR(tx_queue->efx, "TX queue %d spurious TX "
+ "completion id %x\n", tx_queue->queue,
+ read_ptr);
+ /* Don't reset */
+ } else {
+ if (buffer->unmap_len) {
+ if (buffer->unmap_single)
+ pci_unmap_single(pci_dev,
+ buffer->unmap_addr,
+ buffer->unmap_len,
+ PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(pci_dev,
+ buffer->unmap_addr,
+ buffer->unmap_len,
+ PCI_DMA_TODEVICE);
+ buffer->unmap_single = 0;
+ buffer->unmap_len = 0;
+ }
+ if (buffer->skb) {
+ dev_kfree_skb_any((struct sk_buff *)
+ buffer->skb);
+ buffer->skb = NULL;
+ EFX_TRACE(tx_queue->efx, "TX queue %d "
+ "transmission id %x complete\n",
+ tx_queue->queue, read_ptr);
+ }
+ buffer->continuation = 1;
+ buffer->len = 0;
+ }
+ ++tx_queue->read_count;
+ read_ptr = (tx_queue->read_count &
+ tx_queue->efx->type->txd_ring_mask);
+ }
+}
+
+/* Initiate a packet transmission on the specified TX queue.
+ * Note that returning anything other than NETDEV_TX_OK will cause the
+ * OS to free the skb.
+ *
+ * This function is split out from efx_hard_start_xmit to allow the
+ * loopback test to direct packets via specific TX queues. It is
+ * therefore a non-static inline, so as not to penalise performance
+ * for non-loopback transmissions.
+ *
+ * Context: netif_tx_lock held
+ */
+inline int efx_xmit(struct efx_nic *efx,
+ struct efx_tx_queue *tx_queue, struct sk_buff *skb)
+{
+ int rc;
+
+ /* Map fragments for DMA and add to TX queue */
+ rc = efx_enqueue_skb(tx_queue, skb);
+ if (unlikely(rc != NETDEV_TX_OK))
+ goto out;
+
+ /* Update last TX timer */
+ efx->net_dev->trans_start = jiffies;
+
+ out:
+ return rc;
+}
+
+/* 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.
+ */
+int efx_hard_start_xmit(struct sk_buff *skb, struct net_device *net_dev)
+{
+ struct efx_nic *efx = net_dev->priv;
+ return efx_xmit(efx, &efx->tx_queue[0], skb);
+}
+
+void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index)
+{
+ unsigned long flags __attribute__ ((unused));
+ unsigned fill_level;
+ struct efx_nic *efx = tx_queue->efx;
+
+ EFX_BUG_ON_PARANOID(index > efx->type->txd_ring_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
+ * stopped. */
+ smp_mb();
+ if (unlikely(tx_queue->stopped)) {
+ fill_level = tx_queue->insert_count - tx_queue->read_count;
+ if (fill_level < EFX_NETDEV_TX_THRESHOLD(tx_queue)) {
+ /* If the port is stopped and the net_dev isn't
+ * registered, then the caller must be performing
+ * flow control manually */
+ if (unlikely(!efx->net_dev_registered))
+ return;
+
+ /* Do this under netif_tx_lock(), to avoid racing
+ * with efx_xmit(). */
+ netif_tx_lock(efx->net_dev);
+ if (tx_queue->stopped) {
+ tx_queue->stopped = 0;
+ efx_wake_queue(efx);
+ }
+ netif_tx_unlock(efx->net_dev);
+ }
+ }
+}
+
+int efx_probe_tx_queue(struct efx_tx_queue *tx_queue)
+{
+ struct efx_nic *efx = tx_queue->efx;
+ unsigned int txq_size;
+ int i, rc;
+
+ EFX_LOG(efx, "creating TX queue %d\n", tx_queue->queue);
+
+ /* Allocate software ring */
+ txq_size = (efx->type->txd_ring_mask + 1) * sizeof(*tx_queue->buffer);
+ tx_queue->buffer = kzalloc(txq_size, GFP_KERNEL);
+ if (!tx_queue->buffer) {
+ rc = -ENOMEM;
+ goto fail1;
+ }
+ for (i = 0; i <= efx->type->txd_ring_mask; ++i)
+ tx_queue->buffer[i].continuation = 1;
+
+ /* Allocate hardware ring */
+ rc = falcon_probe_tx(tx_queue);
+ if (rc)
+ goto fail2;
+
+ return 0;
+
+ fail2:
+ kfree(tx_queue->buffer);
+ tx_queue->buffer = NULL;
+ fail1:
+ tx_queue->used = 0;
+
+ return rc;
+}
+
+int efx_init_tx_queue(struct efx_tx_queue *tx_queue)
+{
+ EFX_LOG(tx_queue->efx, "initialising TX queue %d\n", tx_queue->queue);
+
+ tx_queue->insert_count = 0;
+ tx_queue->write_count = 0;
+ tx_queue->read_count = 0;
+ tx_queue->old_read_count = 0;
+ BUG_ON(tx_queue->stopped);
+
+ /* Set up TX descriptor ring */
+ return falcon_init_tx(tx_queue);
+}
+
+void efx_release_tx_buffers(struct efx_tx_queue *tx_queue)
+{
+ unsigned int last_index, mask;
+ if (tx_queue->buffer) {
+ /* Free any buffers left in the ring */
+ mask = tx_queue->efx->type->txd_ring_mask;
+ last_index = (tx_queue->insert_count - 1) & mask;
+ EFX_LOG(tx_queue->efx, "Will dequeue up to 0x%x from 0x%x\n",
+ last_index, tx_queue->read_count & mask);
+ efx_dequeue_buffers(tx_queue, last_index);
+ }
+}
+
+void efx_fini_tx_queue(struct efx_tx_queue *tx_queue)
+{
+ EFX_LOG(tx_queue->efx, "shutting down TX queue %d\n", tx_queue->queue);
+
+ /* Flush TX queue, remove descriptor ring */
+ falcon_fini_tx(tx_queue);
+
+ efx_release_tx_buffers(tx_queue);
+
+ /* Release queue's stop on port, if any */
+ if (tx_queue->stopped) {
+ tx_queue->stopped = 0;
+ efx_wake_queue(tx_queue->efx);
+ }
+}
+
+void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
+{
+ EFX_LOG(tx_queue->efx, "destroying TX queue %d\n", tx_queue->queue);
+ falcon_remove_tx(tx_queue);
+
+ kfree(tx_queue->buffer);
+ tx_queue->buffer = NULL;
+ tx_queue->used = 0;
+}
+
+
diff --git a/drivers/net/sfc/tx.h b/drivers/net/sfc/tx.h
new file mode 100644
index 0000000..1526a73
--- /dev/null
+++ b/drivers/net/sfc/tx.h
@@ -0,0 +1,24 @@
+/****************************************************************************
+ * Driver for Solarflare Solarstorm network controllers and boards
+ * Copyright 2006 Fen Systems Ltd.
+ * Copyright 2006-2008 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.
+ */
+
+#ifndef EFX_TX_H
+#define EFX_TX_H
+
+#include "net_driver.h"
+
+int efx_probe_tx_queue(struct efx_tx_queue *tx_queue);
+void efx_remove_tx_queue(struct efx_tx_queue *tx_queue);
+int efx_init_tx_queue(struct efx_tx_queue *tx_queue);
+void efx_fini_tx_queue(struct efx_tx_queue *tx_queue);
+
+int efx_hard_start_xmit(struct sk_buff *skb, struct net_device *net_dev);
+void efx_release_tx_buffers(struct efx_tx_queue *tx_queue);
+
+#endif /* EFX_TX_H */
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
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