diff options
Diffstat (limited to 'drivers/net/sfc/rx.c')
| -rw-r--r-- | drivers/net/sfc/rx.c | 875 |
1 files changed, 875 insertions, 0 deletions
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c new file mode 100644 index 00000000000..551299b462a --- /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 (%)"); + |