410 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/****************************************************************************3 * Driver for Solarflare network controllers and boards4 * Copyright 2005-2006 Fen Systems Ltd.5 * Copyright 2005-2013 Solarflare Communications Inc.6 */7 8#include <linux/socket.h>9#include <linux/in.h>10#include <linux/slab.h>11#include <linux/ip.h>12#include <linux/ipv6.h>13#include <linux/tcp.h>14#include <linux/udp.h>15#include <linux/prefetch.h>16#include <linux/moduleparam.h>17#include <linux/iommu.h>18#include <net/ip.h>19#include <net/checksum.h>20#include <net/xdp.h>21#include <linux/bpf_trace.h>22#include "net_driver.h"23#include "efx.h"24#include "rx_common.h"25#include "filter.h"26#include "nic.h"27#include "selftest.h"28#include "workarounds.h"29 30/* Preferred number of descriptors to fill at once */31#define EFX_RX_PREFERRED_BATCH 8U32 33/* Maximum rx prefix used by any architecture. */34#define EFX_MAX_RX_PREFIX_SIZE 1635 36/* Size of buffer allocated for skb header area. */37#define EFX_SKB_HEADERS 128u38 39/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */40#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \41 EFX_RX_USR_BUF_SIZE)42 43static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,44 struct efx_rx_buffer *rx_buf,45 int len)46{47 struct efx_nic *efx = rx_queue->efx;48 unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;49 50 if (likely(len <= max_len))51 return;52 53 /* The packet must be discarded, but this is only a fatal error54 * if the caller indicated it was55 */56 rx_buf->flags |= EFX_RX_PKT_DISCARD;57 58 if (net_ratelimit())59 netif_err(efx, rx_err, efx->net_dev,60 "RX queue %d overlength RX event (%#x > %#x)\n",61 efx_rx_queue_index(rx_queue), len, max_len);62 63 efx_rx_queue_channel(rx_queue)->n_rx_overlength++;64}65 66/* Allocate and construct an SKB around page fragments */67static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,68 struct efx_rx_buffer *rx_buf,69 unsigned int n_frags,70 u8 *eh, int hdr_len)71{72 struct efx_nic *efx = channel->efx;73 struct sk_buff *skb;74 75 /* Allocate an SKB to store the headers */76 skb = netdev_alloc_skb(efx->net_dev,77 efx->rx_ip_align + efx->rx_prefix_size +78 hdr_len);79 if (unlikely(skb == NULL)) {80 atomic_inc(&efx->n_rx_noskb_drops);81 return NULL;82 }83 84 EFX_WARN_ON_ONCE_PARANOID(rx_buf->len < hdr_len);85 86 memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,87 efx->rx_prefix_size + hdr_len);88 skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);89 __skb_put(skb, hdr_len);90 91 /* Append the remaining page(s) onto the frag list */92 if (rx_buf->len > hdr_len) {93 rx_buf->page_offset += hdr_len;94 rx_buf->len -= hdr_len;95 96 for (;;) {97 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,98 rx_buf->page, rx_buf->page_offset,99 rx_buf->len, efx->rx_buffer_truesize);100 rx_buf->page = NULL;101 102 if (skb_shinfo(skb)->nr_frags == n_frags)103 break;104 105 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);106 }107 } else {108 __free_pages(rx_buf->page, efx->rx_buffer_order);109 rx_buf->page = NULL;110 n_frags = 0;111 }112 113 /* Move past the ethernet header */114 skb->protocol = eth_type_trans(skb, efx->net_dev);115 116 skb_mark_napi_id(skb, &channel->napi_str);117 118 return skb;119}120 121void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,122 unsigned int n_frags, unsigned int len, u16 flags)123{124 struct efx_nic *efx = rx_queue->efx;125 struct efx_channel *channel = efx_rx_queue_channel(rx_queue);126 struct efx_rx_buffer *rx_buf;127 128 rx_queue->rx_packets++;129 130 rx_buf = efx_rx_buffer(rx_queue, index);131 rx_buf->flags |= flags;132 133 /* Validate the number of fragments and completed length */134 if (n_frags == 1) {135 if (!(flags & EFX_RX_PKT_PREFIX_LEN))136 efx_rx_packet__check_len(rx_queue, rx_buf, len);137 } else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||138 unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||139 unlikely(len > n_frags * efx->rx_dma_len) ||140 unlikely(!efx->rx_scatter)) {141 /* If this isn't an explicit discard request, either142 * the hardware or the driver is broken.143 */144 WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));145 rx_buf->flags |= EFX_RX_PKT_DISCARD;146 }147 148 netif_vdbg(efx, rx_status, efx->net_dev,149 "RX queue %d received ids %x-%x len %d %s%s\n",150 efx_rx_queue_index(rx_queue), index,151 (index + n_frags - 1) & rx_queue->ptr_mask, len,152 (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",153 (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");154 155 /* Discard packet, if instructed to do so. Process the156 * previous receive first.157 */158 if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {159 efx_rx_flush_packet(channel);160 efx_discard_rx_packet(channel, rx_buf, n_frags);161 return;162 }163 164 if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))165 rx_buf->len = len;166 167 /* Release and/or sync the DMA mapping - assumes all RX buffers168 * consumed in-order per RX queue.169 */170 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);171 172 /* Prefetch nice and early so data will (hopefully) be in cache by173 * the time we look at it.174 */175 prefetch(efx_rx_buf_va(rx_buf));176 177 rx_buf->page_offset += efx->rx_prefix_size;178 rx_buf->len -= efx->rx_prefix_size;179 180 if (n_frags > 1) {181 /* Release/sync DMA mapping for additional fragments.182 * Fix length for last fragment.183 */184 unsigned int tail_frags = n_frags - 1;185 186 for (;;) {187 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);188 if (--tail_frags == 0)189 break;190 efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);191 }192 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;193 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);194 }195 196 /* All fragments have been DMA-synced, so recycle pages. */197 rx_buf = efx_rx_buffer(rx_queue, index);198 efx_recycle_rx_pages(channel, rx_buf, n_frags);199 200 /* Pipeline receives so that we give time for packet headers to be201 * prefetched into cache.202 */203 efx_rx_flush_packet(channel);204 channel->rx_pkt_n_frags = n_frags;205 channel->rx_pkt_index = index;206}207 208static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,209 struct efx_rx_buffer *rx_buf,210 unsigned int n_frags)211{212 struct sk_buff *skb;213 u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);214 215 skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);216 if (unlikely(skb == NULL)) {217 struct efx_rx_queue *rx_queue;218 219 rx_queue = efx_channel_get_rx_queue(channel);220 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);221 return;222 }223 skb_record_rx_queue(skb, channel->rx_queue.core_index);224 225 /* Set the SKB flags */226 skb_checksum_none_assert(skb);227 if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) {228 skb->ip_summed = CHECKSUM_UNNECESSARY;229 skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);230 }231 232 efx_rx_skb_attach_timestamp(channel, skb);233 234 if (channel->type->receive_skb)235 if (channel->type->receive_skb(channel, skb))236 return;237 238 /* Pass the packet up */239 if (channel->rx_list != NULL)240 /* Add to list, will pass up later */241 list_add_tail(&skb->list, channel->rx_list);242 else243 /* No list, so pass it up now */244 netif_receive_skb(skb);245}246 247/** efx_do_xdp: perform XDP processing on a received packet248 *249 * Returns true if packet should still be delivered.250 */251static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,252 struct efx_rx_buffer *rx_buf, u8 **ehp)253{254 u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE];255 struct efx_rx_queue *rx_queue;256 struct bpf_prog *xdp_prog;257 struct xdp_frame *xdpf;258 struct xdp_buff xdp;259 u32 xdp_act;260 s16 offset;261 int err;262 263 xdp_prog = rcu_dereference_bh(efx->xdp_prog);264 if (!xdp_prog)265 return true;266 267 rx_queue = efx_channel_get_rx_queue(channel);268 269 if (unlikely(channel->rx_pkt_n_frags > 1)) {270 /* We can't do XDP on fragmented packets - drop. */271 efx_free_rx_buffers(rx_queue, rx_buf,272 channel->rx_pkt_n_frags);273 if (net_ratelimit())274 netif_err(efx, rx_err, efx->net_dev,275 "XDP is not possible with multiple receive fragments (%d)\n",276 channel->rx_pkt_n_frags);277 channel->n_rx_xdp_bad_drops++;278 return false;279 }280 281 dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr,282 rx_buf->len, DMA_FROM_DEVICE);283 284 /* Save the rx prefix. */285 EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE);286 memcpy(rx_prefix, *ehp - efx->rx_prefix_size,287 efx->rx_prefix_size);288 289 xdp_init_buff(&xdp, efx->rx_page_buf_step, &rx_queue->xdp_rxq_info);290 /* No support yet for XDP metadata */291 xdp_prepare_buff(&xdp, *ehp - EFX_XDP_HEADROOM, EFX_XDP_HEADROOM,292 rx_buf->len, false);293 294 xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);295 296 offset = (u8 *)xdp.data - *ehp;297 298 switch (xdp_act) {299 case XDP_PASS:300 /* Fix up rx prefix. */301 if (offset) {302 *ehp += offset;303 rx_buf->page_offset += offset;304 rx_buf->len -= offset;305 memcpy(*ehp - efx->rx_prefix_size, rx_prefix,306 efx->rx_prefix_size);307 }308 break;309 310 case XDP_TX:311 /* Buffer ownership passes to tx on success. */312 xdpf = xdp_convert_buff_to_frame(&xdp);313 err = efx_xdp_tx_buffers(efx, 1, &xdpf, true);314 if (unlikely(err != 1)) {315 efx_free_rx_buffers(rx_queue, rx_buf, 1);316 if (net_ratelimit())317 netif_err(efx, rx_err, efx->net_dev,318 "XDP TX failed (%d)\n", err);319 channel->n_rx_xdp_bad_drops++;320 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);321 } else {322 channel->n_rx_xdp_tx++;323 }324 break;325 326 case XDP_REDIRECT:327 err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog);328 if (unlikely(err)) {329 efx_free_rx_buffers(rx_queue, rx_buf, 1);330 if (net_ratelimit())331 netif_err(efx, rx_err, efx->net_dev,332 "XDP redirect failed (%d)\n", err);333 channel->n_rx_xdp_bad_drops++;334 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);335 } else {336 channel->n_rx_xdp_redirect++;337 }338 break;339 340 default:341 bpf_warn_invalid_xdp_action(efx->net_dev, xdp_prog, xdp_act);342 efx_free_rx_buffers(rx_queue, rx_buf, 1);343 channel->n_rx_xdp_bad_drops++;344 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);345 break;346 347 case XDP_ABORTED:348 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);349 fallthrough;350 case XDP_DROP:351 efx_free_rx_buffers(rx_queue, rx_buf, 1);352 channel->n_rx_xdp_drops++;353 break;354 }355 356 return xdp_act == XDP_PASS;357}358 359/* Handle a received packet. Second half: Touches packet payload. */360void __efx_rx_packet(struct efx_channel *channel)361{362 struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);363 struct efx_nic *efx = channel->efx;364 struct efx_rx_buffer *rx_buf =365 efx_rx_buffer(rx_queue, channel->rx_pkt_index);366 u8 *eh = efx_rx_buf_va(rx_buf);367 368 /* Read length from the prefix if necessary. This already369 * excludes the length of the prefix itself.370 */371 if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN) {372 rx_buf->len = le16_to_cpup((__le16 *)373 (eh + efx->rx_packet_len_offset));374 /* A known issue may prevent this being filled in;375 * if that happens, just drop the packet.376 * Must do that in the driver since passing a zero-length377 * packet up to the stack may cause a crash.378 */379 if (unlikely(!rx_buf->len)) {380 efx_free_rx_buffers(rx_queue, rx_buf,381 channel->rx_pkt_n_frags);382 channel->n_rx_frm_trunc++;383 goto out;384 }385 }386 387 /* If we're in loopback test, then pass the packet directly to the388 * loopback layer, and free the rx_buf here389 */390 if (unlikely(efx->loopback_selftest)) {391 efx_loopback_rx_packet(efx, eh, rx_buf->len);392 efx_free_rx_buffers(rx_queue, rx_buf,393 channel->rx_pkt_n_frags);394 goto out;395 }396 397 if (!efx_do_xdp(efx, channel, rx_buf, &eh))398 goto out;399 400 if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))401 rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;402 403 if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)404 efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh, 0);405 else406 efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);407out:408 channel->rx_pkt_n_frags = 0;409}410