diff options
Diffstat (limited to 'drivers/net/ethernet/sfc/rx.c')
| -rw-r--r-- | drivers/net/ethernet/sfc/rx.c | 749 |
1 files changed, 749 insertions, 0 deletions
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c new file mode 100644 index 000000000000..62e43649466e --- /dev/null +++ b/drivers/net/ethernet/sfc/rx.c @@ -0,0 +1,749 @@ +/**************************************************************************** + * Driver for Solarflare Solarstorm network controllers and boards + * Copyright 2005-2006 Fen Systems Ltd. + * Copyright 2005-2011 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/slab.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/prefetch.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 + +/* Maximum size of a buffer sharing a page */ +#define EFX_RX_HALF_PAGE ((PAGE_SIZE >> 1) - sizeof(struct efx_rx_page_state)) + +/* 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 GRO 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 GRO is less + * than the performance hit of using page-based allocation of non-GRO, + * so the watermarks should reflect this. + * + * Per channel we maintain a single variable, updated by each channel: + * + * rx_alloc_level += (gro_performed ? RX_ALLOC_FACTOR_GRO : + * 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_GRO ? + * RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB) + */ +static int rx_alloc_method = RX_ALLOC_METHOD_AUTO; + +#define RX_ALLOC_LEVEL_GRO 0x2000 +#define RX_ALLOC_LEVEL_MAX 0x3000 +#define RX_ALLOC_FACTOR_GRO 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 + +/* Offset of ethernet header within page */ +static inline unsigned int efx_rx_buf_offset(struct efx_nic *efx, + 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->dma_addr & (PAGE_SIZE - 1)) + + efx->type->rx_buffer_hash_size); +} +static inline unsigned int efx_rx_buf_size(struct efx_nic *efx) +{ + return PAGE_SIZE << efx->rx_buffer_order; +} + +static u8 *efx_rx_buf_eh(struct efx_nic *efx, struct efx_rx_buffer *buf) +{ + if (buf->is_page) + return page_address(buf->u.page) + efx_rx_buf_offset(efx, buf); + else + return ((u8 *)buf->u.skb->data + + efx->type->rx_buffer_hash_size); +} + +static inline u32 efx_rx_buf_hash(const u8 *eh) +{ + /* The ethernet header is always directly after any hash. */ +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || NET_IP_ALIGN % 4 == 0 + return __le32_to_cpup((const __le32 *)(eh - 4)); +#else + const u8 *data = eh - 4; + return ((u32)data[0] | + (u32)data[1] << 8 | + (u32)data[2] << 16 | + (u32)data[3] << 24); +#endif +} + +/** + * efx_init_rx_buffers_skb - create EFX_RX_BATCH skb-based RX buffers + * + * @rx_queue: Efx RX queue + * + * This allocates EFX_RX_BATCH skbs, maps them for DMA, and populates a + * struct efx_rx_buffer for each one. Return a negative error code or 0 + * on success. May fail having only inserted fewer than EFX_RX_BATCH + * buffers. + */ +static int efx_init_rx_buffers_skb(struct efx_rx_queue *rx_queue) +{ + struct efx_nic *efx = rx_queue->efx; + struct net_device *net_dev = efx->net_dev; + struct efx_rx_buffer *rx_buf; + struct sk_buff *skb; + int skb_len = efx->rx_buffer_len; + unsigned index, count; + + for (count = 0; count < EFX_RX_BATCH; ++count) { + index = rx_queue->added_count & rx_queue->ptr_mask; + rx_buf = efx_rx_buffer(rx_queue, index); + + rx_buf->u.skb = skb = netdev_alloc_skb(net_dev, skb_len); + if (unlikely(!skb)) + return -ENOMEM; + + /* Adjust the SKB for padding and checksum */ + skb_reserve(skb, NET_IP_ALIGN); + rx_buf->len = skb_len - NET_IP_ALIGN; + rx_buf->is_page = false; + skb->ip_summed = CHECKSUM_UNNECESSARY; + + rx_buf->dma_addr = pci_map_single(efx->pci_dev, + skb->data, rx_buf->len, + PCI_DMA_FROMDEVICE); + if (unlikely(pci_dma_mapping_error(efx->pci_dev, + rx_buf->dma_addr))) { + dev_kfree_skb_any(skb); + rx_buf->u.skb = NULL; + return -EIO; + } + + ++rx_queue->added_count; + ++rx_queue->alloc_skb_count; + } + + return 0; +} + +/** + * efx_init_rx_buffers_page - create EFX_RX_BATCH page-based RX buffers + * + * @rx_queue: Efx RX queue + * + * This allocates memory for EFX_RX_BATCH receive buffers, maps them for DMA, + * and populates struct efx_rx_buffers for each one. Return a negative error + * code or 0 on success. If a single page can be split between two buffers, + * then the page will either be inserted fully, or not at at all. + */ +static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue) +{ + struct efx_nic *efx = rx_queue->efx; + struct efx_rx_buffer *rx_buf; + struct page *page; + void *page_addr; + struct efx_rx_page_state *state; + dma_addr_t dma_addr; + unsigned index, count; + + /* We can split a page between two buffers */ + BUILD_BUG_ON(EFX_RX_BATCH & 1); + + for (count = 0; count < EFX_RX_BATCH; ++count) { + page = alloc_pages(__GFP_COLD | __GFP_COMP | GFP_ATOMIC, + efx->rx_buffer_order); + if (unlikely(page == NULL)) + return -ENOMEM; + dma_addr = pci_map_page(efx->pci_dev, page, 0, + efx_rx_buf_size(efx), + PCI_DMA_FROMDEVICE); + if (unlikely(pci_dma_mapping_error(efx->pci_dev, dma_addr))) { + __free_pages(page, efx->rx_buffer_order); + return -EIO; + } + page_addr = page_address(page); + state = page_addr; + state->refcnt = 0; + state->dma_addr = dma_addr; + + page_addr += sizeof(struct efx_rx_page_state); + dma_addr += sizeof(struct efx_rx_page_state); + + split: + index = rx_queue->added_count & rx_queue->ptr_mask; + rx_buf = efx_rx_buffer(rx_queue, index); + rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN; + rx_buf->u.page = page; + rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN; + rx_buf->is_page = true; + ++rx_queue->added_count; + ++rx_queue->alloc_page_count; + ++state->refcnt; + + if ((~count & 1) && (efx->rx_buffer_len <= EFX_RX_HALF_PAGE)) { + /* Use the second half of the page */ + get_page(page); + dma_addr += (PAGE_SIZE >> 1); + page_addr += (PAGE_SIZE >> 1); + ++count; + goto split; + } + } + + return 0; +} + +static void efx_unmap_rx_buffer(struct efx_nic *efx, + struct efx_rx_buffer *rx_buf) +{ + if (rx_buf->is_page && rx_buf->u.page) { + struct efx_rx_page_state *state; + + state = page_address(rx_buf->u.page); + if (--state->refcnt == 0) { + pci_unmap_page(efx->pci_dev, + state->dma_addr, + efx_rx_buf_size(efx), + PCI_DMA_FROMDEVICE); + } + } else if (!rx_buf->is_page && rx_buf->u.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->is_page && rx_buf->u.page) { + __free_pages(rx_buf->u.page, efx->rx_buffer_order); + rx_buf->u.page = NULL; + } else if (!rx_buf->is_page && rx_buf->u.skb) { + dev_kfree_skb_any(rx_buf->u.skb); + rx_buf->u.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); +} + +/* Attempt to resurrect the other receive buffer that used to share this page, + * which had previously been passed up to the kernel and freed. */ +static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue, + struct efx_rx_buffer *rx_buf) +{ + struct efx_rx_page_state *state = page_address(rx_buf->u.page); + struct efx_rx_buffer *new_buf; + unsigned fill_level, index; + + /* +1 because efx_rx_packet() incremented removed_count. +1 because + * we'd like to insert an additional descriptor whilst leaving + * EFX_RXD_HEAD_ROOM for the non-recycle path */ + fill_level = (rx_queue->added_count - rx_queue->removed_count + 2); + if (unlikely(fill_level > rx_queue->max_fill)) { + /* We could place "state" on a list, and drain the list in + * efx_fast_push_rx_descriptors(). For now, this will do. */ + return; + } + + ++state->refcnt; + get_page(rx_buf->u.page); + + index = rx_queue->added_count & rx_queue->ptr_mask; + new_buf = efx_rx_buffer(rx_queue, index); + new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1); + new_buf->u.page = rx_buf->u.page; + new_buf->len = rx_buf->len; + new_buf->is_page = true; + ++rx_queue->added_count; +} + +/* Recycle the given rx buffer directly back into the rx_queue. There is + * always room to add this buffer, because we've just popped a buffer. */ +static void efx_recycle_rx_buffer(struct efx_channel *channel, + struct efx_rx_buffer *rx_buf) +{ + struct efx_nic *efx = channel->efx; + struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel); + struct efx_rx_buffer *new_buf; + unsigned index; + + if (rx_buf->is_page && efx->rx_buffer_len <= EFX_RX_HALF_PAGE && + page_count(rx_buf->u.page) == 1) + efx_resurrect_rx_buffer(rx_queue, rx_buf); + + index = rx_queue->added_count & rx_queue->ptr_mask; + new_buf = efx_rx_buffer(rx_queue, index); + + memcpy(new_buf, rx_buf, sizeof(*new_buf)); + rx_buf->u.page = NULL; + ++rx_queue->added_count; +} + +/** + * 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 atomic + * memory to do so, a slow fill will be scheduled. + * + * The caller must provide serialisation (none is used here). In practise, + * this means this function must run from the NAPI handler, or be called + * when NAPI is disabled. + */ +void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue) +{ + struct efx_channel *channel = efx_rx_queue_channel(rx_queue); + unsigned fill_level; + int space, rc = 0; + + /* Calculate current fill level, and exit if we don't need to fill */ + fill_level = (rx_queue->added_count - rx_queue->removed_count); + EFX_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries); + if (fill_level >= rx_queue->fast_fill_trigger) + goto out; + + /* Record minimum fill level */ + if (unlikely(fill_level < rx_queue->min_fill)) { + if (fill_level) + rx_queue->min_fill = fill_level; + } + + space = rx_queue->fast_fill_limit - fill_level; + if (space < EFX_RX_BATCH) + goto out; + + netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev, + "RX queue %d fast-filling descriptor ring from" + " level %d to level %d using %s allocation\n", + efx_rx_queue_index(rx_queue), fill_level, + rx_queue->fast_fill_limit, + channel->rx_alloc_push_pages ? "page" : "skb"); + + do { + if (channel->rx_alloc_push_pages) + rc = efx_init_rx_buffers_page(rx_queue); + else + rc = efx_init_rx_buffers_skb(rx_queue); + if (unlikely(rc)) { + /* Ensure that we don't leave the rx queue empty */ + if (rx_queue->added_count == rx_queue->removed_count) + efx_schedule_slow_fill(rx_queue); + goto out; + } + } while ((space -= EFX_RX_BATCH) >= EFX_RX_BATCH); + + netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev, + "RX queue %d fast-filled descriptor ring " + "to level %d\n", efx_rx_queue_index(rx_queue), + rx_queue->added_count - rx_queue->removed_count); + + out: + if (rx_queue->notified_count != rx_queue->added_count) + efx_nic_notify_rx_desc(rx_queue); +} + +void efx_rx_slow_fill(unsigned long context) +{ + struct efx_rx_queue *rx_queue = (struct efx_rx_queue *)context; + struct efx_channel *channel = efx_rx_queue_channel(rx_queue); + + /* Post an event to cause NAPI to run and refill the queue */ + efx_nic_generate_fill_event(channel); + ++rx_queue->slow_fill_count; +} + +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)) { + if (net_ratelimit()) + netif_err(efx, rx_err, efx->net_dev, + " RX queue %d seriously overlength " + "RX event (0x%x > 0x%x+0x%x). Leaking\n", + efx_rx_queue_index(rx_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->is_page; + efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY); + } else { + if (net_ratelimit()) + netif_err(efx, rx_err, efx->net_dev, + " RX queue %d overlength RX event " + "(0x%x > 0x%x)\n", + efx_rx_queue_index(rx_queue), len, max_len); + } + + efx_rx_queue_channel(rx_queue)->n_rx_overlength++; +} + +/* Pass a received packet up through the generic GRO stack + * + * Handles driverlink veto, and passes the fragment up via + * the appropriate GRO method + */ +static void efx_rx_packet_gro(struct efx_channel *channel, + struct efx_rx_buffer *rx_buf, + const u8 *eh, bool checksummed) +{ + struct napi_struct *napi = &channel->napi_str; + gro_result_t gro_result; + + /* Pass the skb/page into the GRO engine */ + if (rx_buf->is_page) { + struct efx_nic *efx = channel->efx; + struct page *page = rx_buf->u.page; + struct sk_buff *skb; + + rx_buf->u.page = NULL; + + skb = napi_get_frags(napi); + if (!skb) { + put_page(page); + return; + } + + if (efx->net_dev->features & NETIF_F_RXHASH) + skb->rxhash = efx_rx_buf_hash(eh); + + skb_shinfo(skb)->frags[0].page = page; + skb_shinfo(skb)->frags[0].page_offset = + efx_rx_buf_offset(efx, 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->u.skb; + + EFX_BUG_ON_PARANOID(!checksummed); + rx_buf->u.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_GRO; + 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_channel *channel = efx_rx_queue_channel(rx_queue); + struct efx_rx_buffer *rx_buf; + bool leak_packet = false; + + rx_buf = efx_rx_buffer(rx_queue, index); + + /* 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); + + netif_vdbg(efx, rx_status, efx->net_dev, + "RX queue %d received id %x at %llx+%x %s%s\n", + efx_rx_queue_index(rx_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)) + channel->n_skbuff_leaks++; + else + efx_recycle_rx_buffer(channel, rx_buf); + + /* Don't hold off the previous receive */ + rx_buf = NULL; + goto out; + } + + /* 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(efx_rx_buf_eh(efx, rx_buf)); + + /* Pipeline receives so that we give time for packet headers to be + * prefetched into cache. + */ + rx_buf->len = len - efx->type->rx_buffer_hash_size; +out: + if (channel->rx_pkt) + __efx_rx_packet(channel, + channel->rx_pkt, channel->rx_pkt_csummed); + channel->rx_pkt = rx_buf; + 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; + u8 *eh = efx_rx_buf_eh(efx, rx_buf); + + /* 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, eh, rx_buf->len); + efx_free_rx_buffer(efx, rx_buf); + return; + } + + if (!rx_buf->is_page) { + skb = rx_buf->u.skb; + + prefetch(skb_shinfo(skb)); + + skb_reserve(skb, efx->type->rx_buffer_hash_size); + skb_put(skb, rx_buf->len); + + if (efx->net_dev->features & NETIF_F_RXHASH) + skb->rxhash = efx_rx_buf_hash(eh); + + /* Move past the ethernet header. rx_buf->data still points + * at the ethernet header */ + skb->protocol = eth_type_trans(skb, efx->net_dev); + + skb_record_rx_queue(skb, channel->channel); + } + + if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM))) + checksummed = false; + + if (likely(checksummed || rx_buf->is_page)) { + efx_rx_packet_gro(channel, rx_buf, eh, checksummed); + return; + } + + /* We now own the SKB */ + skb = rx_buf->u.skb; + rx_buf->u.skb = NULL; + + /* Set the SKB flags */ + skb_checksum_none_assert(skb); + + /* 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 GRO 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_GRO) ? + 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 entries; + int rc; + + /* Create the smallest power-of-two aligned ring */ + entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE); + EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE); + rx_queue->ptr_mask = entries - 1; + + netif_dbg(efx, probe, efx->net_dev, + "creating RX queue %d size %#x mask %#x\n", + efx_rx_queue_index(rx_queue), efx->rxq_entries, + rx_queue->ptr_mask); + + /* Allocate RX buffers */ + rx_queue->buffer = kzalloc(entries * sizeof(*rx_queue->buffer), + 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) +{ + struct efx_nic *efx = rx_queue->efx; + unsigned int max_fill, trigger, limit; + + netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev, + "initialising RX queue %d\n", efx_rx_queue_index(rx_queue)); + + /* Initialise ptr fields */ + rx_queue->added_count = 0; + rx_queue->notified_count = 0; + rx_queue->removed_count = 0; + rx_queue->min_fill = -1U; + + /* Initialise limit fields */ + max_fill = efx->rxq_entries - 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; + + netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev, + "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue)); + + del_timer_sync(&rx_queue->slow_fill); + 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 <= rx_queue->ptr_mask; i++) { + rx_buf = efx_rx_buffer(rx_queue, i); + efx_fini_rx_buffer(rx_queue, rx_buf); + } + } +} + +void efx_remove_rx_queue(struct efx_rx_queue *rx_queue) +{ + netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev, + "destroying RX queue %d\n", efx_rx_queue_index(rx_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 (%)"); + |