1// SPDX-License-Identifier: GPL-2.0-only 2/**************************************************************************** 3 * Driver for Solarflare network controllers and boards 4 * 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 8U 32 33/* Maximum rx prefix used by any architecture. */ 34#define EFX_MAX_RX_PREFIX_SIZE 16 35 36/* Size of buffer allocated for skb header area. */ 37#define EFX_SKB_HEADERS 128u 38 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 error 54 * if the caller indicated it was 55 */ 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, either 142 * 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 the 156 * 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 buffers 168 * 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 by 173 * 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 be 201 * 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 else 243 /* No list, so pass it up now */ 244 netif_receive_skb(skb); 245} 246 247/** efx_do_xdp: perform XDP processing on a received packet 248 * 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 already 369 * 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-length 377 * 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 the 388 * loopback layer, and free the rx_buf here 389 */ 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 else 406 efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags); 407out: 408 channel->rx_pkt_n_frags = 0; 409} 410