diff options
Diffstat (limited to 'drivers/net/ethernet/sfc/rx.c')
| -rw-r--r-- | drivers/net/ethernet/sfc/rx.c | 803 |
1 files changed, 803 insertions, 0 deletions
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c new file mode 100644 index 00000000..5173eaac --- /dev/null +++ b/drivers/net/ethernet/sfc/rx.c @@ -0,0 +1,803 @@ +/**************************************************************************** + * 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 <linux/moduleparam.h> +#include <linux/iommu.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" + +/* Preferred number of descriptors to fill at once */ +#define EFX_RX_PREFERRED_BATCH 8U + +/* Number of RX buffers to recycle pages for. When creating the RX page recycle + * ring, this number is divided by the number of buffers per page to calculate + * the number of pages to store in the RX page recycle ring. + */ +#define EFX_RECYCLE_RING_SIZE_IOMMU 4096 +#define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH) + +/* Size of buffer allocated for skb header area. */ +#define EFX_SKB_HEADERS 64u + +/* 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; + +/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */ +#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \ + EFX_RX_USR_BUF_SIZE) + +/* + * RX maximum head room required. + * + * This must be at least 1 to prevent overflow, plus one packet-worth + * to allow pipelined receives. + */ +#define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS) + +static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf) +{ + return page_address(buf->page) + buf->page_offset; +} + +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 +} + +static inline struct efx_rx_buffer * +efx_rx_buf_next(struct efx_rx_queue *rx_queue, struct efx_rx_buffer *rx_buf) +{ + if (unlikely(rx_buf == efx_rx_buffer(rx_queue, rx_queue->ptr_mask))) + return efx_rx_buffer(rx_queue, 0); + else + return rx_buf + 1; +} + +static inline void efx_sync_rx_buffer(struct efx_nic *efx, + struct efx_rx_buffer *rx_buf, + unsigned int len) +{ + dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len, + DMA_FROM_DEVICE); +} + +void efx_rx_config_page_split(struct efx_nic *efx) +{ + efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + NET_IP_ALIGN, + EFX_RX_BUF_ALIGNMENT); + efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 : + ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) / + efx->rx_page_buf_step); + efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) / + efx->rx_bufs_per_page; + efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH, + efx->rx_bufs_per_page); +} + +/* Check the RX page recycle ring for a page that can be reused. */ +static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue) +{ + struct efx_nic *efx = rx_queue->efx; + struct page *page; + struct efx_rx_page_state *state; + unsigned index; + + index = rx_queue->page_remove & rx_queue->page_ptr_mask; + page = rx_queue->page_ring[index]; + if (page == NULL) + return NULL; + + rx_queue->page_ring[index] = NULL; + /* page_remove cannot exceed page_add. */ + if (rx_queue->page_remove != rx_queue->page_add) + ++rx_queue->page_remove; + + /* If page_count is 1 then we hold the only reference to this page. */ + if (page_count(page) == 1) { + ++rx_queue->page_recycle_count; + return page; + } else { + state = page_address(page); + dma_unmap_page(&efx->pci_dev->dev, state->dma_addr, + PAGE_SIZE << efx->rx_buffer_order, + DMA_FROM_DEVICE); + put_page(page); + ++rx_queue->page_recycle_failed; + } + + return NULL; +} + +/** + * efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers + * + * @rx_queue: Efx RX queue + * + * This allocates a batch of pages, 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 used for multiple buffers, + * then the page will either be inserted fully, or not at all. + */ +static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue) +{ + struct efx_nic *efx = rx_queue->efx; + struct efx_rx_buffer *rx_buf; + struct page *page; + unsigned int page_offset; + struct efx_rx_page_state *state; + dma_addr_t dma_addr; + unsigned index, count; + + count = 0; + do { + page = efx_reuse_page(rx_queue); + if (page == NULL) { + page = alloc_pages(__GFP_COLD | __GFP_COMP | GFP_ATOMIC, + efx->rx_buffer_order); + if (unlikely(page == NULL)) + return -ENOMEM; + dma_addr = + dma_map_page(&efx->pci_dev->dev, page, 0, + PAGE_SIZE << efx->rx_buffer_order, + DMA_FROM_DEVICE); + if (unlikely(dma_mapping_error(&efx->pci_dev->dev, + dma_addr))) { + __free_pages(page, efx->rx_buffer_order); + return -EIO; + } + state = page_address(page); + state->dma_addr = dma_addr; + } else { + state = page_address(page); + dma_addr = state->dma_addr; + } + + dma_addr += sizeof(struct efx_rx_page_state); + page_offset = sizeof(struct efx_rx_page_state); + + do { + index = rx_queue->added_count & rx_queue->ptr_mask; + rx_buf = efx_rx_buffer(rx_queue, index); + rx_buf->dma_addr = dma_addr + NET_IP_ALIGN; + rx_buf->page = page; + rx_buf->page_offset = page_offset + NET_IP_ALIGN; + rx_buf->len = efx->rx_dma_len; + rx_buf->flags = 0; + ++rx_queue->added_count; + get_page(page); + dma_addr += efx->rx_page_buf_step; + page_offset += efx->rx_page_buf_step; + } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE); + + rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE; + } while (++count < efx->rx_pages_per_batch); + + return 0; +} + +/* Unmap a DMA-mapped page. This function is only called for the final RX + * buffer in a page. + */ +static void efx_unmap_rx_buffer(struct efx_nic *efx, + struct efx_rx_buffer *rx_buf) +{ + struct page *page = rx_buf->page; + + if (page) { + struct efx_rx_page_state *state = page_address(page); + dma_unmap_page(&efx->pci_dev->dev, + state->dma_addr, + PAGE_SIZE << efx->rx_buffer_order, + DMA_FROM_DEVICE); + } +} + +static void efx_free_rx_buffer(struct efx_rx_buffer *rx_buf) +{ + if (rx_buf->page) { + put_page(rx_buf->page); + rx_buf->page = NULL; + } +} + +/* Attempt to recycle the page if there is an RX recycle ring; the page can + * only be added if this is the final RX buffer, to prevent pages being used in + * the descriptor ring and appearing in the recycle ring simultaneously. + */ +static void efx_recycle_rx_page(struct efx_channel *channel, + struct efx_rx_buffer *rx_buf) +{ + struct page *page = rx_buf->page; + struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel); + struct efx_nic *efx = rx_queue->efx; + unsigned index; + + /* Only recycle the page after processing the final buffer. */ + if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE)) + return; + + index = rx_queue->page_add & rx_queue->page_ptr_mask; + if (rx_queue->page_ring[index] == NULL) { + unsigned read_index = rx_queue->page_remove & + rx_queue->page_ptr_mask; + + /* The next slot in the recycle ring is available, but + * increment page_remove if the read pointer currently + * points here. + */ + if (read_index == index) + ++rx_queue->page_remove; + rx_queue->page_ring[index] = page; + ++rx_queue->page_add; + return; + } + ++rx_queue->page_recycle_full; + efx_unmap_rx_buffer(efx, rx_buf); + put_page(rx_buf->page); +} + +static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue, + struct efx_rx_buffer *rx_buf) +{ + /* Release the page reference we hold for the buffer. */ + if (rx_buf->page) + put_page(rx_buf->page); + + /* If this is the last buffer in a page, unmap and free it. */ + if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) { + efx_unmap_rx_buffer(rx_queue->efx, rx_buf); + efx_free_rx_buffer(rx_buf); + } + rx_buf->page = NULL; +} + +/* Recycle the pages that are used by buffers that have just been received. */ +static void efx_recycle_rx_pages(struct efx_channel *channel, + struct efx_rx_buffer *rx_buf, + unsigned int n_frags) +{ + struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel); + + do { + efx_recycle_rx_page(channel, rx_buf); + rx_buf = efx_rx_buf_next(rx_queue, rx_buf); + } while (--n_frags); +} + +static void efx_discard_rx_packet(struct efx_channel *channel, + struct efx_rx_buffer *rx_buf, + unsigned int n_frags) +{ + struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel); + + efx_recycle_rx_pages(channel, rx_buf, n_frags); + + do { + efx_free_rx_buffer(rx_buf); + rx_buf = efx_rx_buf_next(rx_queue, rx_buf); + } while (--n_frags); +} + +/** + * 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->@max_fill. 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_nic *efx = rx_queue->efx; + unsigned int fill_level, batch_size; + 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; + } + + batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page; + space = rx_queue->max_fill - fill_level; + EFX_BUG_ON_PARANOID(space < batch_size); + + 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\n", + efx_rx_queue_index(rx_queue), fill_level, + rx_queue->max_fill); + + + do { + rc = efx_init_rx_buffers(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 -= batch_size) >= batch_size); + + 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; + + /* Post an event to cause NAPI to run and refill the queue */ + efx_nic_generate_fill_event(rx_queue); + ++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) +{ + 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 + */ + rx_buf->flags |= EFX_RX_PKT_DISCARD; + + 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); + 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 GRO. GRO can handle pages + * regardless of checksum state and skbs with a good checksum. + */ +static void +efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf, + unsigned int n_frags, u8 *eh) +{ + struct napi_struct *napi = &channel->napi_str; + gro_result_t gro_result; + struct efx_nic *efx = channel->efx; + struct sk_buff *skb; + + skb = napi_get_frags(napi); + if (unlikely(!skb)) { + while (n_frags--) { + put_page(rx_buf->page); + rx_buf->page = NULL; + rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf); + } + return; + } + + if (efx->net_dev->features & NETIF_F_RXHASH) + skb->rxhash = efx_rx_buf_hash(eh); + skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ? + CHECKSUM_UNNECESSARY : CHECKSUM_NONE); + + for (;;) { + skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, + rx_buf->page, rx_buf->page_offset, + rx_buf->len); + rx_buf->page = NULL; + skb->len += rx_buf->len; + if (skb_shinfo(skb)->nr_frags == n_frags) + break; + + rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf); + } + + skb->data_len = skb->len; + skb->truesize += n_frags * efx->rx_buffer_truesize; + + skb_record_rx_queue(skb, channel->rx_queue.core_index); + + gro_result = napi_gro_frags(napi); + if (gro_result != GRO_DROP) + channel->irq_mod_score += 2; +} + +/* Allocate and construct an SKB around page fragments */ +static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel, + struct efx_rx_buffer *rx_buf, + unsigned int n_frags, + u8 *eh, int hdr_len) +{ + struct efx_nic *efx = channel->efx; + 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)) + return NULL; + + EFX_BUG_ON_PARANOID(rx_buf->len < hdr_len); + + skb_reserve(skb, EFX_PAGE_SKB_ALIGN); + memcpy(__skb_put(skb, hdr_len), eh, hdr_len); + + /* Append the remaining page(s) onto the frag list */ + if (rx_buf->len > hdr_len) { + rx_buf->page_offset += hdr_len; + rx_buf->len -= hdr_len; + + for (;;) { + skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, + rx_buf->page, rx_buf->page_offset, + rx_buf->len); + rx_buf->page = NULL; + skb->len += rx_buf->len; + skb->data_len += rx_buf->len; + if (skb_shinfo(skb)->nr_frags == n_frags) + break; + + rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf); + } + } else { + __free_pages(rx_buf->page, efx->rx_buffer_order); + rx_buf->page = NULL; + n_frags = 0; + } + + skb->truesize += n_frags * efx->rx_buffer_truesize; + + /* 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 n_frags, unsigned int len, u16 flags) +{ + struct efx_nic *efx = rx_queue->efx; + struct efx_channel *channel = efx_rx_queue_channel(rx_queue); + struct efx_rx_buffer *rx_buf; + + rx_buf = efx_rx_buffer(rx_queue, index); + rx_buf->flags |= flags; + + /* Validate the number of fragments and completed length */ + if (n_frags == 1) { + efx_rx_packet__check_len(rx_queue, rx_buf, len); + } else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) || + unlikely(len <= (n_frags - 1) * EFX_RX_USR_BUF_SIZE) || + unlikely(len > n_frags * EFX_RX_USR_BUF_SIZE) || + unlikely(!efx->rx_scatter)) { + /* If this isn't an explicit discard request, either + * the hardware or the driver is broken. + */ + WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD)); + rx_buf->flags |= EFX_RX_PKT_DISCARD; + } + + netif_vdbg(efx, rx_status, efx->net_dev, + "RX queue %d received ids %x-%x len %d %s%s\n", + efx_rx_queue_index(rx_queue), index, + (index + n_frags - 1) & rx_queue->ptr_mask, len, + (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "", + (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : ""); + + /* Discard packet, if instructed to do so. Process the + * previous receive first. + */ + if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) { + efx_rx_flush_packet(channel); + efx_discard_rx_packet(channel, rx_buf, n_frags); + return; + } + + if (n_frags == 1) + rx_buf->len = len; + + /* Release and/or sync the DMA mapping - assumes all RX buffers + * consumed in-order per RX queue. + */ + efx_sync_rx_buffer(efx, rx_buf, rx_buf->len); + + /* Prefetch nice and early so data will (hopefully) be in cache by + * the time we look at it. + */ + prefetch(efx_rx_buf_va(rx_buf)); + + rx_buf->page_offset += efx->type->rx_buffer_hash_size; + rx_buf->len -= efx->type->rx_buffer_hash_size; + + if (n_frags > 1) { + /* Release/sync DMA mapping for additional fragments. + * Fix length for last fragment. + */ + unsigned int tail_frags = n_frags - 1; + + for (;;) { + rx_buf = efx_rx_buf_next(rx_queue, rx_buf); + if (--tail_frags == 0) + break; + efx_sync_rx_buffer(efx, rx_buf, EFX_RX_USR_BUF_SIZE); + } + rx_buf->len = len - (n_frags - 1) * EFX_RX_USR_BUF_SIZE; + efx_sync_rx_buffer(efx, rx_buf, rx_buf->len); + } + + /* All fragments have been DMA-synced, so recycle pages. */ + rx_buf = efx_rx_buffer(rx_queue, index); + efx_recycle_rx_pages(channel, rx_buf, n_frags); + + /* Pipeline receives so that we give time for packet headers to be + * prefetched into cache. + */ + efx_rx_flush_packet(channel); + channel->rx_pkt_n_frags = n_frags; + channel->rx_pkt_index = index; +} + +static void efx_rx_deliver(struct efx_channel *channel, u8 *eh, + struct efx_rx_buffer *rx_buf, + unsigned int n_frags) +{ + struct sk_buff *skb; + u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS); + + skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len); + if (unlikely(skb == NULL)) { + efx_free_rx_buffer(rx_buf); + return; + } + skb_record_rx_queue(skb, channel->rx_queue.core_index); + + /* Set the SKB flags */ + skb_checksum_none_assert(skb); + + if (channel->type->receive_skb) + if (channel->type->receive_skb(channel, skb)) + return; + + /* Pass the packet up */ + netif_receive_skb(skb); +} + +/* Handle a received packet. Second half: Touches packet payload. */ +void __efx_rx_packet(struct efx_channel *channel) +{ + struct efx_nic *efx = channel->efx; + struct efx_rx_buffer *rx_buf = + efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index); + u8 *eh = efx_rx_buf_va(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(rx_buf); + goto out; + } + + if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM))) + rx_buf->flags &= ~EFX_RX_PKT_CSUMMED; + + if (!channel->type->receive_skb) + efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh); + else + efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags); +out: + channel->rx_pkt_n_frags = 0; +} + +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 = kcalloc(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; +} + +static void efx_init_rx_recycle_ring(struct efx_nic *efx, + struct efx_rx_queue *rx_queue) +{ + unsigned int bufs_in_recycle_ring, page_ring_size; + + /* Set the RX recycle ring size */ +#ifdef CONFIG_PPC64 + bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU; +#else + if (efx->pci_dev->dev.iommu_group) + bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU; + else + bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU; +#endif /* CONFIG_PPC64 */ + + page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring / + efx->rx_bufs_per_page); + rx_queue->page_ring = kcalloc(page_ring_size, + sizeof(*rx_queue->page_ring), GFP_KERNEL); + rx_queue->page_ptr_mask = page_ring_size - 1; +} + +void efx_init_rx_queue(struct efx_rx_queue *rx_queue) +{ + struct efx_nic *efx = rx_queue->efx; + unsigned int max_fill, trigger, max_trigger; + + 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; + efx_init_rx_recycle_ring(efx, rx_queue); + + rx_queue->page_remove = 0; + rx_queue->page_add = rx_queue->page_ptr_mask + 1; + rx_queue->page_recycle_count = 0; + rx_queue->page_recycle_failed = 0; + rx_queue->page_recycle_full = 0; + + /* Initialise limit fields */ + max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM; + max_trigger = + max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page; + if (rx_refill_threshold != 0) { + trigger = max_fill * min(rx_refill_threshold, 100U) / 100U; + if (trigger > max_trigger) + trigger = max_trigger; + } else { + trigger = max_trigger; + } + + rx_queue->max_fill = max_fill; + rx_queue->fast_fill_trigger = trigger; + + /* Set up RX descriptor ring */ + rx_queue->enabled = true; + efx_nic_init_rx(rx_queue); +} + +void efx_fini_rx_queue(struct efx_rx_queue *rx_queue) +{ + int i; + struct efx_nic *efx = rx_queue->efx; + 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)); + + /* A flush failure might have left rx_queue->enabled */ + rx_queue->enabled = false; + + del_timer_sync(&rx_queue->slow_fill); + efx_nic_fini_rx(rx_queue); + + /* Release RX buffers from the current read ptr to the write ptr */ + if (rx_queue->buffer) { + for (i = rx_queue->removed_count; i < rx_queue->added_count; + i++) { + unsigned index = i & rx_queue->ptr_mask; + rx_buf = efx_rx_buffer(rx_queue, index); + efx_fini_rx_buffer(rx_queue, rx_buf); + } + } + + /* Unmap and release the pages in the recycle ring. Remove the ring. */ + for (i = 0; i <= rx_queue->page_ptr_mask; i++) { + struct page *page = rx_queue->page_ring[i]; + struct efx_rx_page_state *state; + + if (page == NULL) + continue; + + state = page_address(page); + dma_unmap_page(&efx->pci_dev->dev, state->dma_addr, + PAGE_SIZE << efx->rx_buffer_order, + DMA_FROM_DEVICE); + put_page(page); + } + kfree(rx_queue->page_ring); + rx_queue->page_ring = NULL; +} + +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_refill_threshold, uint, 0444); +MODULE_PARM_DESC(rx_refill_threshold, + "RX descriptor ring refill threshold (%)"); + |