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 43 static 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 */ 67 static 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_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, 98 rx_buf->page, rx_buf->page_offset, 99 rx_buf->len); 100 rx_buf->page = NULL; 101 skb->len += rx_buf->len; 102 skb->data_len += rx_buf->len; 103 if (skb_shinfo(skb)->nr_frags == n_frags) 104 break; 105 106 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf); 107 } 108 } else { 109 __free_pages(rx_buf->page, efx->rx_buffer_order); 110 rx_buf->page = NULL; 111 n_frags = 0; 112 } 113 114 skb->truesize += n_frags * efx->rx_buffer_truesize; 115 116 /* Move past the ethernet header */ 117 skb->protocol = eth_type_trans(skb, efx->net_dev); 118 119 skb_mark_napi_id(skb, &channel->napi_str); 120 121 return skb; 122 } 123 124 void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index, 125 unsigned int n_frags, unsigned int len, u16 flags) 126 { 127 struct efx_nic *efx = rx_queue->efx; 128 struct efx_channel *channel = efx_rx_queue_channel(rx_queue); 129 struct efx_rx_buffer *rx_buf; 130 131 rx_queue->rx_packets++; 132 133 rx_buf = efx_rx_buffer(rx_queue, index); 134 rx_buf->flags |= flags; 135 136 /* Validate the number of fragments and completed length */ 137 if (n_frags == 1) { 138 if (!(flags & EFX_RX_PKT_PREFIX_LEN)) 139 efx_rx_packet__check_len(rx_queue, rx_buf, len); 140 } else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) || 141 unlikely(len <= (n_frags - 1) * efx->rx_dma_len) || 142 unlikely(len > n_frags * efx->rx_dma_len) || 143 unlikely(!efx->rx_scatter)) { 144 /* If this isn't an explicit discard request, either 145 * the hardware or the driver is broken. 146 */ 147 WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD)); 148 rx_buf->flags |= EFX_RX_PKT_DISCARD; 149 } 150 151 netif_vdbg(efx, rx_status, efx->net_dev, 152 "RX queue %d received ids %x-%x len %d %s%s\n", 153 efx_rx_queue_index(rx_queue), index, 154 (index + n_frags - 1) & rx_queue->ptr_mask, len, 155 (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "", 156 (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : ""); 157 158 /* Discard packet, if instructed to do so. Process the 159 * previous receive first. 160 */ 161 if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) { 162 efx_rx_flush_packet(channel); 163 efx_discard_rx_packet(channel, rx_buf, n_frags); 164 return; 165 } 166 167 if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN)) 168 rx_buf->len = len; 169 170 /* Release and/or sync the DMA mapping - assumes all RX buffers 171 * consumed in-order per RX queue. 172 */ 173 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len); 174 175 /* Prefetch nice and early so data will (hopefully) be in cache by 176 * the time we look at it. 177 */ 178 prefetch(efx_rx_buf_va(rx_buf)); 179 180 rx_buf->page_offset += efx->rx_prefix_size; 181 rx_buf->len -= efx->rx_prefix_size; 182 183 if (n_frags > 1) { 184 /* Release/sync DMA mapping for additional fragments. 185 * Fix length for last fragment. 186 */ 187 unsigned int tail_frags = n_frags - 1; 188 189 for (;;) { 190 rx_buf = efx_rx_buf_next(rx_queue, rx_buf); 191 if (--tail_frags == 0) 192 break; 193 efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len); 194 } 195 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len; 196 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len); 197 } 198 199 /* All fragments have been DMA-synced, so recycle pages. */ 200 rx_buf = efx_rx_buffer(rx_queue, index); 201 efx_recycle_rx_pages(channel, rx_buf, n_frags); 202 203 /* Pipeline receives so that we give time for packet headers to be 204 * prefetched into cache. 205 */ 206 efx_rx_flush_packet(channel); 207 channel->rx_pkt_n_frags = n_frags; 208 channel->rx_pkt_index = index; 209 } 210 211 static void efx_rx_deliver(struct efx_channel *channel, u8 *eh, 212 struct efx_rx_buffer *rx_buf, 213 unsigned int n_frags) 214 { 215 struct sk_buff *skb; 216 u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS); 217 218 skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len); 219 if (unlikely(skb == NULL)) { 220 struct efx_rx_queue *rx_queue; 221 222 rx_queue = efx_channel_get_rx_queue(channel); 223 efx_free_rx_buffers(rx_queue, rx_buf, n_frags); 224 return; 225 } 226 skb_record_rx_queue(skb, channel->rx_queue.core_index); 227 228 /* Set the SKB flags */ 229 skb_checksum_none_assert(skb); 230 if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) { 231 skb->ip_summed = CHECKSUM_UNNECESSARY; 232 skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL); 233 } 234 235 efx_rx_skb_attach_timestamp(channel, skb); 236 237 if (channel->type->receive_skb) 238 if (channel->type->receive_skb(channel, skb)) 239 return; 240 241 /* Pass the packet up */ 242 if (channel->rx_list != NULL) 243 /* Add to list, will pass up later */ 244 list_add_tail(&skb->list, channel->rx_list); 245 else 246 /* No list, so pass it up now */ 247 netif_receive_skb(skb); 248 } 249 250 /** efx_do_xdp: perform XDP processing on a received packet 251 * 252 * Returns true if packet should still be delivered. 253 */ 254 static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel, 255 struct efx_rx_buffer *rx_buf, u8 **ehp) 256 { 257 u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE]; 258 struct efx_rx_queue *rx_queue; 259 struct bpf_prog *xdp_prog; 260 struct xdp_frame *xdpf; 261 struct xdp_buff xdp; 262 u32 xdp_act; 263 s16 offset; 264 int err; 265 266 rcu_read_lock(); 267 xdp_prog = rcu_dereference(efx->xdp_prog); 268 if (!xdp_prog) { 269 rcu_read_unlock(); 270 return true; 271 } 272 273 rx_queue = efx_channel_get_rx_queue(channel); 274 275 if (unlikely(channel->rx_pkt_n_frags > 1)) { 276 /* We can't do XDP on fragmented packets - drop. */ 277 rcu_read_unlock(); 278 efx_free_rx_buffers(rx_queue, rx_buf, 279 channel->rx_pkt_n_frags); 280 if (net_ratelimit()) 281 netif_err(efx, rx_err, efx->net_dev, 282 "XDP is not possible with multiple receive fragments (%d)\n", 283 channel->rx_pkt_n_frags); 284 channel->n_rx_xdp_bad_drops++; 285 return false; 286 } 287 288 dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, 289 rx_buf->len, DMA_FROM_DEVICE); 290 291 /* Save the rx prefix. */ 292 EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE); 293 memcpy(rx_prefix, *ehp - efx->rx_prefix_size, 294 efx->rx_prefix_size); 295 296 xdp.data = *ehp; 297 xdp.data_hard_start = xdp.data - EFX_XDP_HEADROOM; 298 299 /* No support yet for XDP metadata */ 300 xdp_set_data_meta_invalid(&xdp); 301 xdp.data_end = xdp.data + rx_buf->len; 302 xdp.rxq = &rx_queue->xdp_rxq_info; 303 xdp.frame_sz = efx->rx_page_buf_step; 304 305 xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp); 306 rcu_read_unlock(); 307 308 offset = (u8 *)xdp.data - *ehp; 309 310 switch (xdp_act) { 311 case XDP_PASS: 312 /* Fix up rx prefix. */ 313 if (offset) { 314 *ehp += offset; 315 rx_buf->page_offset += offset; 316 rx_buf->len -= offset; 317 memcpy(*ehp - efx->rx_prefix_size, rx_prefix, 318 efx->rx_prefix_size); 319 } 320 break; 321 322 case XDP_TX: 323 /* Buffer ownership passes to tx on success. */ 324 xdpf = xdp_convert_buff_to_frame(&xdp); 325 err = efx_xdp_tx_buffers(efx, 1, &xdpf, true); 326 if (unlikely(err != 1)) { 327 efx_free_rx_buffers(rx_queue, rx_buf, 1); 328 if (net_ratelimit()) 329 netif_err(efx, rx_err, efx->net_dev, 330 "XDP TX failed (%d)\n", err); 331 channel->n_rx_xdp_bad_drops++; 332 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act); 333 } else { 334 channel->n_rx_xdp_tx++; 335 } 336 break; 337 338 case XDP_REDIRECT: 339 err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog); 340 if (unlikely(err)) { 341 efx_free_rx_buffers(rx_queue, rx_buf, 1); 342 if (net_ratelimit()) 343 netif_err(efx, rx_err, efx->net_dev, 344 "XDP redirect failed (%d)\n", err); 345 channel->n_rx_xdp_bad_drops++; 346 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act); 347 } else { 348 channel->n_rx_xdp_redirect++; 349 } 350 break; 351 352 default: 353 bpf_warn_invalid_xdp_action(xdp_act); 354 efx_free_rx_buffers(rx_queue, rx_buf, 1); 355 channel->n_rx_xdp_bad_drops++; 356 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act); 357 break; 358 359 case XDP_ABORTED: 360 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act); 361 /* Fall through */ 362 case XDP_DROP: 363 efx_free_rx_buffers(rx_queue, rx_buf, 1); 364 channel->n_rx_xdp_drops++; 365 break; 366 } 367 368 return xdp_act == XDP_PASS; 369 } 370 371 /* Handle a received packet. Second half: Touches packet payload. */ 372 void __efx_rx_packet(struct efx_channel *channel) 373 { 374 struct efx_nic *efx = channel->efx; 375 struct efx_rx_buffer *rx_buf = 376 efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index); 377 u8 *eh = efx_rx_buf_va(rx_buf); 378 379 /* Read length from the prefix if necessary. This already 380 * excludes the length of the prefix itself. 381 */ 382 if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN) 383 rx_buf->len = le16_to_cpup((__le16 *) 384 (eh + efx->rx_packet_len_offset)); 385 386 /* If we're in loopback test, then pass the packet directly to the 387 * loopback layer, and free the rx_buf here 388 */ 389 if (unlikely(efx->loopback_selftest)) { 390 struct efx_rx_queue *rx_queue; 391 392 efx_loopback_rx_packet(efx, eh, rx_buf->len); 393 rx_queue = efx_channel_get_rx_queue(channel); 394 efx_free_rx_buffers(rx_queue, rx_buf, 395 channel->rx_pkt_n_frags); 396 goto out; 397 } 398 399 if (!efx_do_xdp(efx, channel, rx_buf, &eh)) 400 goto out; 401 402 if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM))) 403 rx_buf->flags &= ~EFX_RX_PKT_CSUMMED; 404 405 if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb) 406 efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh, 0); 407 else 408 efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags); 409 out: 410 channel->rx_pkt_n_frags = 0; 411 } 412