| 1 | /* A simple network driver using virtio. |
| 2 | * |
| 3 | * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | */ |
| 19 | //#define DEBUG |
| 20 | #include <linux/netdevice.h> |
| 21 | #include <linux/etherdevice.h> |
| 22 | #include <linux/ethtool.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/virtio.h> |
| 25 | #include <linux/virtio_net.h> |
| 26 | #include <linux/scatterlist.h> |
| 27 | |
| 28 | static int napi_weight = 128; |
| 29 | module_param(napi_weight, int, 0444); |
| 30 | |
| 31 | static int csum = 1, gso = 1; |
| 32 | module_param(csum, bool, 0444); |
| 33 | module_param(gso, bool, 0444); |
| 34 | |
| 35 | /* FIXME: MTU in config. */ |
| 36 | #define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN) |
| 37 | #define GOOD_COPY_LEN 128 |
| 38 | |
| 39 | struct virtnet_info |
| 40 | { |
| 41 | struct virtio_device *vdev; |
| 42 | struct virtqueue *rvq, *svq; |
| 43 | struct net_device *dev; |
| 44 | struct napi_struct napi; |
| 45 | |
| 46 | /* The skb we couldn't send because buffers were full. */ |
| 47 | struct sk_buff *last_xmit_skb; |
| 48 | |
| 49 | /* If we need to free in a timer, this is it. */ |
| 50 | struct timer_list xmit_free_timer; |
| 51 | |
| 52 | /* Number of input buffers, and max we've ever had. */ |
| 53 | unsigned int num, max; |
| 54 | |
| 55 | /* For cleaning up after transmission. */ |
| 56 | struct tasklet_struct tasklet; |
| 57 | bool free_in_tasklet; |
| 58 | |
| 59 | /* I like... big packets and I cannot lie! */ |
| 60 | bool big_packets; |
| 61 | |
| 62 | /* Host will merge rx buffers for big packets (shake it! shake it!) */ |
| 63 | bool mergeable_rx_bufs; |
| 64 | |
| 65 | /* Receive & send queues. */ |
| 66 | struct sk_buff_head recv; |
| 67 | struct sk_buff_head send; |
| 68 | |
| 69 | /* Chain pages by the private ptr. */ |
| 70 | struct page *pages; |
| 71 | }; |
| 72 | |
| 73 | static inline void *skb_vnet_hdr(struct sk_buff *skb) |
| 74 | { |
| 75 | return (struct virtio_net_hdr *)skb->cb; |
| 76 | } |
| 77 | |
| 78 | static void give_a_page(struct virtnet_info *vi, struct page *page) |
| 79 | { |
| 80 | page->private = (unsigned long)vi->pages; |
| 81 | vi->pages = page; |
| 82 | } |
| 83 | |
| 84 | static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb) |
| 85 | { |
| 86 | unsigned int i; |
| 87 | |
| 88 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
| 89 | give_a_page(vi, skb_shinfo(skb)->frags[i].page); |
| 90 | skb_shinfo(skb)->nr_frags = 0; |
| 91 | skb->data_len = 0; |
| 92 | } |
| 93 | |
| 94 | static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) |
| 95 | { |
| 96 | struct page *p = vi->pages; |
| 97 | |
| 98 | if (p) |
| 99 | vi->pages = (struct page *)p->private; |
| 100 | else |
| 101 | p = alloc_page(gfp_mask); |
| 102 | return p; |
| 103 | } |
| 104 | |
| 105 | static void skb_xmit_done(struct virtqueue *svq) |
| 106 | { |
| 107 | struct virtnet_info *vi = svq->vdev->priv; |
| 108 | |
| 109 | /* Suppress further interrupts. */ |
| 110 | svq->vq_ops->disable_cb(svq); |
| 111 | |
| 112 | /* We were probably waiting for more output buffers. */ |
| 113 | netif_wake_queue(vi->dev); |
| 114 | |
| 115 | /* Make sure we re-xmit last_xmit_skb: if there are no more packets |
| 116 | * queued, start_xmit won't be called. */ |
| 117 | tasklet_schedule(&vi->tasklet); |
| 118 | } |
| 119 | |
| 120 | static void receive_skb(struct net_device *dev, struct sk_buff *skb, |
| 121 | unsigned len) |
| 122 | { |
| 123 | struct virtnet_info *vi = netdev_priv(dev); |
| 124 | struct virtio_net_hdr *hdr = skb_vnet_hdr(skb); |
| 125 | int err; |
| 126 | int i; |
| 127 | |
| 128 | if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { |
| 129 | pr_debug("%s: short packet %i\n", dev->name, len); |
| 130 | dev->stats.rx_length_errors++; |
| 131 | goto drop; |
| 132 | } |
| 133 | |
| 134 | if (vi->mergeable_rx_bufs) { |
| 135 | struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb); |
| 136 | unsigned int copy; |
| 137 | char *p = page_address(skb_shinfo(skb)->frags[0].page); |
| 138 | |
| 139 | if (len > PAGE_SIZE) |
| 140 | len = PAGE_SIZE; |
| 141 | len -= sizeof(struct virtio_net_hdr_mrg_rxbuf); |
| 142 | |
| 143 | memcpy(hdr, p, sizeof(*mhdr)); |
| 144 | p += sizeof(*mhdr); |
| 145 | |
| 146 | copy = len; |
| 147 | if (copy > skb_tailroom(skb)) |
| 148 | copy = skb_tailroom(skb); |
| 149 | |
| 150 | memcpy(skb_put(skb, copy), p, copy); |
| 151 | |
| 152 | len -= copy; |
| 153 | |
| 154 | if (!len) { |
| 155 | give_a_page(vi, skb_shinfo(skb)->frags[0].page); |
| 156 | skb_shinfo(skb)->nr_frags--; |
| 157 | } else { |
| 158 | skb_shinfo(skb)->frags[0].page_offset += |
| 159 | sizeof(*mhdr) + copy; |
| 160 | skb_shinfo(skb)->frags[0].size = len; |
| 161 | skb->data_len += len; |
| 162 | skb->len += len; |
| 163 | } |
| 164 | |
| 165 | while (--mhdr->num_buffers) { |
| 166 | struct sk_buff *nskb; |
| 167 | |
| 168 | i = skb_shinfo(skb)->nr_frags; |
| 169 | if (i >= MAX_SKB_FRAGS) { |
| 170 | pr_debug("%s: packet too long %d\n", dev->name, |
| 171 | len); |
| 172 | dev->stats.rx_length_errors++; |
| 173 | goto drop; |
| 174 | } |
| 175 | |
| 176 | nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len); |
| 177 | if (!nskb) { |
| 178 | pr_debug("%s: rx error: %d buffers missing\n", |
| 179 | dev->name, mhdr->num_buffers); |
| 180 | dev->stats.rx_length_errors++; |
| 181 | goto drop; |
| 182 | } |
| 183 | |
| 184 | __skb_unlink(nskb, &vi->recv); |
| 185 | vi->num--; |
| 186 | |
| 187 | skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0]; |
| 188 | skb_shinfo(nskb)->nr_frags = 0; |
| 189 | kfree_skb(nskb); |
| 190 | |
| 191 | if (len > PAGE_SIZE) |
| 192 | len = PAGE_SIZE; |
| 193 | |
| 194 | skb_shinfo(skb)->frags[i].size = len; |
| 195 | skb_shinfo(skb)->nr_frags++; |
| 196 | skb->data_len += len; |
| 197 | skb->len += len; |
| 198 | } |
| 199 | } else { |
| 200 | len -= sizeof(struct virtio_net_hdr); |
| 201 | |
| 202 | if (len <= MAX_PACKET_LEN) |
| 203 | trim_pages(vi, skb); |
| 204 | |
| 205 | err = pskb_trim(skb, len); |
| 206 | if (err) { |
| 207 | pr_debug("%s: pskb_trim failed %i %d\n", dev->name, |
| 208 | len, err); |
| 209 | dev->stats.rx_dropped++; |
| 210 | goto drop; |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | skb->truesize += skb->data_len; |
| 215 | dev->stats.rx_bytes += skb->len; |
| 216 | dev->stats.rx_packets++; |
| 217 | |
| 218 | if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { |
| 219 | pr_debug("Needs csum!\n"); |
| 220 | if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset)) |
| 221 | goto frame_err; |
| 222 | } |
| 223 | |
| 224 | skb->protocol = eth_type_trans(skb, dev); |
| 225 | pr_debug("Receiving skb proto 0x%04x len %i type %i\n", |
| 226 | ntohs(skb->protocol), skb->len, skb->pkt_type); |
| 227 | |
| 228 | if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { |
| 229 | pr_debug("GSO!\n"); |
| 230 | switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { |
| 231 | case VIRTIO_NET_HDR_GSO_TCPV4: |
| 232 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; |
| 233 | break; |
| 234 | case VIRTIO_NET_HDR_GSO_UDP: |
| 235 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
| 236 | break; |
| 237 | case VIRTIO_NET_HDR_GSO_TCPV6: |
| 238 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; |
| 239 | break; |
| 240 | default: |
| 241 | if (net_ratelimit()) |
| 242 | printk(KERN_WARNING "%s: bad gso type %u.\n", |
| 243 | dev->name, hdr->gso_type); |
| 244 | goto frame_err; |
| 245 | } |
| 246 | |
| 247 | if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) |
| 248 | skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; |
| 249 | |
| 250 | skb_shinfo(skb)->gso_size = hdr->gso_size; |
| 251 | if (skb_shinfo(skb)->gso_size == 0) { |
| 252 | if (net_ratelimit()) |
| 253 | printk(KERN_WARNING "%s: zero gso size.\n", |
| 254 | dev->name); |
| 255 | goto frame_err; |
| 256 | } |
| 257 | |
| 258 | /* Header must be checked, and gso_segs computed. */ |
| 259 | skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; |
| 260 | skb_shinfo(skb)->gso_segs = 0; |
| 261 | } |
| 262 | |
| 263 | netif_receive_skb(skb); |
| 264 | return; |
| 265 | |
| 266 | frame_err: |
| 267 | dev->stats.rx_frame_errors++; |
| 268 | drop: |
| 269 | dev_kfree_skb(skb); |
| 270 | } |
| 271 | |
| 272 | static void try_fill_recv_maxbufs(struct virtnet_info *vi) |
| 273 | { |
| 274 | struct sk_buff *skb; |
| 275 | struct scatterlist sg[2+MAX_SKB_FRAGS]; |
| 276 | int num, err, i; |
| 277 | |
| 278 | sg_init_table(sg, 2+MAX_SKB_FRAGS); |
| 279 | for (;;) { |
| 280 | struct virtio_net_hdr *hdr; |
| 281 | |
| 282 | skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN); |
| 283 | if (unlikely(!skb)) |
| 284 | break; |
| 285 | |
| 286 | skb_put(skb, MAX_PACKET_LEN); |
| 287 | |
| 288 | hdr = skb_vnet_hdr(skb); |
| 289 | sg_init_one(sg, hdr, sizeof(*hdr)); |
| 290 | |
| 291 | if (vi->big_packets) { |
| 292 | for (i = 0; i < MAX_SKB_FRAGS; i++) { |
| 293 | skb_frag_t *f = &skb_shinfo(skb)->frags[i]; |
| 294 | f->page = get_a_page(vi, GFP_ATOMIC); |
| 295 | if (!f->page) |
| 296 | break; |
| 297 | |
| 298 | f->page_offset = 0; |
| 299 | f->size = PAGE_SIZE; |
| 300 | |
| 301 | skb->data_len += PAGE_SIZE; |
| 302 | skb->len += PAGE_SIZE; |
| 303 | |
| 304 | skb_shinfo(skb)->nr_frags++; |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; |
| 309 | skb_queue_head(&vi->recv, skb); |
| 310 | |
| 311 | err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb); |
| 312 | if (err) { |
| 313 | skb_unlink(skb, &vi->recv); |
| 314 | trim_pages(vi, skb); |
| 315 | kfree_skb(skb); |
| 316 | break; |
| 317 | } |
| 318 | vi->num++; |
| 319 | } |
| 320 | if (unlikely(vi->num > vi->max)) |
| 321 | vi->max = vi->num; |
| 322 | vi->rvq->vq_ops->kick(vi->rvq); |
| 323 | } |
| 324 | |
| 325 | static void try_fill_recv(struct virtnet_info *vi) |
| 326 | { |
| 327 | struct sk_buff *skb; |
| 328 | struct scatterlist sg[1]; |
| 329 | int err; |
| 330 | |
| 331 | if (!vi->mergeable_rx_bufs) { |
| 332 | try_fill_recv_maxbufs(vi); |
| 333 | return; |
| 334 | } |
| 335 | |
| 336 | for (;;) { |
| 337 | skb_frag_t *f; |
| 338 | |
| 339 | skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN); |
| 340 | if (unlikely(!skb)) |
| 341 | break; |
| 342 | |
| 343 | skb_reserve(skb, NET_IP_ALIGN); |
| 344 | |
| 345 | f = &skb_shinfo(skb)->frags[0]; |
| 346 | f->page = get_a_page(vi, GFP_ATOMIC); |
| 347 | if (!f->page) { |
| 348 | kfree_skb(skb); |
| 349 | break; |
| 350 | } |
| 351 | |
| 352 | f->page_offset = 0; |
| 353 | f->size = PAGE_SIZE; |
| 354 | |
| 355 | skb_shinfo(skb)->nr_frags++; |
| 356 | |
| 357 | sg_init_one(sg, page_address(f->page), PAGE_SIZE); |
| 358 | skb_queue_head(&vi->recv, skb); |
| 359 | |
| 360 | err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb); |
| 361 | if (err) { |
| 362 | skb_unlink(skb, &vi->recv); |
| 363 | kfree_skb(skb); |
| 364 | break; |
| 365 | } |
| 366 | vi->num++; |
| 367 | } |
| 368 | if (unlikely(vi->num > vi->max)) |
| 369 | vi->max = vi->num; |
| 370 | vi->rvq->vq_ops->kick(vi->rvq); |
| 371 | } |
| 372 | |
| 373 | static void skb_recv_done(struct virtqueue *rvq) |
| 374 | { |
| 375 | struct virtnet_info *vi = rvq->vdev->priv; |
| 376 | /* Schedule NAPI, Suppress further interrupts if successful. */ |
| 377 | if (netif_rx_schedule_prep(&vi->napi)) { |
| 378 | rvq->vq_ops->disable_cb(rvq); |
| 379 | __netif_rx_schedule(&vi->napi); |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | static int virtnet_poll(struct napi_struct *napi, int budget) |
| 384 | { |
| 385 | struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); |
| 386 | struct sk_buff *skb = NULL; |
| 387 | unsigned int len, received = 0; |
| 388 | |
| 389 | again: |
| 390 | while (received < budget && |
| 391 | (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) { |
| 392 | __skb_unlink(skb, &vi->recv); |
| 393 | receive_skb(vi->dev, skb, len); |
| 394 | vi->num--; |
| 395 | received++; |
| 396 | } |
| 397 | |
| 398 | /* FIXME: If we oom and completely run out of inbufs, we need |
| 399 | * to start a timer trying to fill more. */ |
| 400 | if (vi->num < vi->max / 2) |
| 401 | try_fill_recv(vi); |
| 402 | |
| 403 | /* Out of packets? */ |
| 404 | if (received < budget) { |
| 405 | netif_rx_complete(napi); |
| 406 | if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) |
| 407 | && napi_schedule_prep(napi)) { |
| 408 | vi->rvq->vq_ops->disable_cb(vi->rvq); |
| 409 | __netif_rx_schedule(napi); |
| 410 | goto again; |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | return received; |
| 415 | } |
| 416 | |
| 417 | static void free_old_xmit_skbs(struct virtnet_info *vi) |
| 418 | { |
| 419 | struct sk_buff *skb; |
| 420 | unsigned int len; |
| 421 | |
| 422 | while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) { |
| 423 | pr_debug("Sent skb %p\n", skb); |
| 424 | __skb_unlink(skb, &vi->send); |
| 425 | vi->dev->stats.tx_bytes += skb->len; |
| 426 | vi->dev->stats.tx_packets++; |
| 427 | kfree_skb(skb); |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | /* If the virtio transport doesn't always notify us when all in-flight packets |
| 432 | * are consumed, we fall back to using this function on a timer to free them. */ |
| 433 | static void xmit_free(unsigned long data) |
| 434 | { |
| 435 | struct virtnet_info *vi = (void *)data; |
| 436 | |
| 437 | netif_tx_lock(vi->dev); |
| 438 | |
| 439 | free_old_xmit_skbs(vi); |
| 440 | |
| 441 | if (!skb_queue_empty(&vi->send)) |
| 442 | mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10)); |
| 443 | |
| 444 | netif_tx_unlock(vi->dev); |
| 445 | } |
| 446 | |
| 447 | static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) |
| 448 | { |
| 449 | int num, err; |
| 450 | struct scatterlist sg[2+MAX_SKB_FRAGS]; |
| 451 | struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb); |
| 452 | struct virtio_net_hdr *hdr = skb_vnet_hdr(skb); |
| 453 | const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; |
| 454 | |
| 455 | sg_init_table(sg, 2+MAX_SKB_FRAGS); |
| 456 | |
| 457 | pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); |
| 458 | |
| 459 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| 460 | hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; |
| 461 | hdr->csum_start = skb->csum_start - skb_headroom(skb); |
| 462 | hdr->csum_offset = skb->csum_offset; |
| 463 | } else { |
| 464 | hdr->flags = 0; |
| 465 | hdr->csum_offset = hdr->csum_start = 0; |
| 466 | } |
| 467 | |
| 468 | if (skb_is_gso(skb)) { |
| 469 | hdr->hdr_len = skb_transport_header(skb) - skb->data; |
| 470 | hdr->gso_size = skb_shinfo(skb)->gso_size; |
| 471 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) |
| 472 | hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; |
| 473 | else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) |
| 474 | hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; |
| 475 | else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) |
| 476 | hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP; |
| 477 | else |
| 478 | BUG(); |
| 479 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) |
| 480 | hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; |
| 481 | } else { |
| 482 | hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; |
| 483 | hdr->gso_size = hdr->hdr_len = 0; |
| 484 | } |
| 485 | |
| 486 | mhdr->num_buffers = 0; |
| 487 | |
| 488 | /* Encode metadata header at front. */ |
| 489 | if (vi->mergeable_rx_bufs) |
| 490 | sg_init_one(sg, mhdr, sizeof(*mhdr)); |
| 491 | else |
| 492 | sg_init_one(sg, hdr, sizeof(*hdr)); |
| 493 | |
| 494 | num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; |
| 495 | |
| 496 | err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb); |
| 497 | if (!err && !vi->free_in_tasklet) |
| 498 | mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10)); |
| 499 | |
| 500 | return err; |
| 501 | } |
| 502 | |
| 503 | static void xmit_tasklet(unsigned long data) |
| 504 | { |
| 505 | struct virtnet_info *vi = (void *)data; |
| 506 | |
| 507 | netif_tx_lock_bh(vi->dev); |
| 508 | if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) { |
| 509 | vi->svq->vq_ops->kick(vi->svq); |
| 510 | vi->last_xmit_skb = NULL; |
| 511 | } |
| 512 | if (vi->free_in_tasklet) |
| 513 | free_old_xmit_skbs(vi); |
| 514 | netif_tx_unlock_bh(vi->dev); |
| 515 | } |
| 516 | |
| 517 | static int start_xmit(struct sk_buff *skb, struct net_device *dev) |
| 518 | { |
| 519 | struct virtnet_info *vi = netdev_priv(dev); |
| 520 | |
| 521 | again: |
| 522 | /* Free up any pending old buffers before queueing new ones. */ |
| 523 | free_old_xmit_skbs(vi); |
| 524 | |
| 525 | /* If we has a buffer left over from last time, send it now. */ |
| 526 | if (unlikely(vi->last_xmit_skb) && |
| 527 | xmit_skb(vi, vi->last_xmit_skb) != 0) |
| 528 | goto stop_queue; |
| 529 | |
| 530 | vi->last_xmit_skb = NULL; |
| 531 | |
| 532 | /* Put new one in send queue and do transmit */ |
| 533 | if (likely(skb)) { |
| 534 | __skb_queue_head(&vi->send, skb); |
| 535 | if (xmit_skb(vi, skb) != 0) { |
| 536 | vi->last_xmit_skb = skb; |
| 537 | skb = NULL; |
| 538 | goto stop_queue; |
| 539 | } |
| 540 | } |
| 541 | done: |
| 542 | vi->svq->vq_ops->kick(vi->svq); |
| 543 | return NETDEV_TX_OK; |
| 544 | |
| 545 | stop_queue: |
| 546 | pr_debug("%s: virtio not prepared to send\n", dev->name); |
| 547 | netif_stop_queue(dev); |
| 548 | |
| 549 | /* Activate callback for using skbs: if this returns false it |
| 550 | * means some were used in the meantime. */ |
| 551 | if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { |
| 552 | vi->svq->vq_ops->disable_cb(vi->svq); |
| 553 | netif_start_queue(dev); |
| 554 | goto again; |
| 555 | } |
| 556 | if (skb) { |
| 557 | /* Drop this skb: we only queue one. */ |
| 558 | vi->dev->stats.tx_dropped++; |
| 559 | kfree_skb(skb); |
| 560 | } |
| 561 | goto done; |
| 562 | } |
| 563 | |
| 564 | #ifdef CONFIG_NET_POLL_CONTROLLER |
| 565 | static void virtnet_netpoll(struct net_device *dev) |
| 566 | { |
| 567 | struct virtnet_info *vi = netdev_priv(dev); |
| 568 | |
| 569 | napi_schedule(&vi->napi); |
| 570 | } |
| 571 | #endif |
| 572 | |
| 573 | static int virtnet_open(struct net_device *dev) |
| 574 | { |
| 575 | struct virtnet_info *vi = netdev_priv(dev); |
| 576 | |
| 577 | napi_enable(&vi->napi); |
| 578 | |
| 579 | /* If all buffers were filled by other side before we napi_enabled, we |
| 580 | * won't get another interrupt, so process any outstanding packets |
| 581 | * now. virtnet_poll wants re-enable the queue, so we disable here. |
| 582 | * We synchronize against interrupts via NAPI_STATE_SCHED */ |
| 583 | if (netif_rx_schedule_prep(&vi->napi)) { |
| 584 | vi->rvq->vq_ops->disable_cb(vi->rvq); |
| 585 | __netif_rx_schedule(&vi->napi); |
| 586 | } |
| 587 | return 0; |
| 588 | } |
| 589 | |
| 590 | static int virtnet_close(struct net_device *dev) |
| 591 | { |
| 592 | struct virtnet_info *vi = netdev_priv(dev); |
| 593 | |
| 594 | napi_disable(&vi->napi); |
| 595 | |
| 596 | return 0; |
| 597 | } |
| 598 | |
| 599 | static int virtnet_set_tx_csum(struct net_device *dev, u32 data) |
| 600 | { |
| 601 | struct virtnet_info *vi = netdev_priv(dev); |
| 602 | struct virtio_device *vdev = vi->vdev; |
| 603 | |
| 604 | if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) |
| 605 | return -ENOSYS; |
| 606 | |
| 607 | return ethtool_op_set_tx_hw_csum(dev, data); |
| 608 | } |
| 609 | |
| 610 | static struct ethtool_ops virtnet_ethtool_ops = { |
| 611 | .set_tx_csum = virtnet_set_tx_csum, |
| 612 | .set_sg = ethtool_op_set_sg, |
| 613 | .set_tso = ethtool_op_set_tso, |
| 614 | }; |
| 615 | |
| 616 | #define MIN_MTU 68 |
| 617 | #define MAX_MTU 65535 |
| 618 | |
| 619 | static int virtnet_change_mtu(struct net_device *dev, int new_mtu) |
| 620 | { |
| 621 | if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) |
| 622 | return -EINVAL; |
| 623 | dev->mtu = new_mtu; |
| 624 | return 0; |
| 625 | } |
| 626 | |
| 627 | static const struct net_device_ops virtnet_netdev = { |
| 628 | .ndo_open = virtnet_open, |
| 629 | .ndo_stop = virtnet_close, |
| 630 | .ndo_start_xmit = start_xmit, |
| 631 | .ndo_validate_addr = eth_validate_addr, |
| 632 | .ndo_set_mac_address = eth_mac_addr, |
| 633 | .ndo_change_mtu = virtnet_change_mtu, |
| 634 | #ifdef CONFIG_NET_POLL_CONTROLLER |
| 635 | .ndo_poll_controller = virtnet_netpoll, |
| 636 | #endif |
| 637 | }; |
| 638 | |
| 639 | static int virtnet_probe(struct virtio_device *vdev) |
| 640 | { |
| 641 | int err; |
| 642 | struct net_device *dev; |
| 643 | struct virtnet_info *vi; |
| 644 | |
| 645 | /* Allocate ourselves a network device with room for our info */ |
| 646 | dev = alloc_etherdev(sizeof(struct virtnet_info)); |
| 647 | if (!dev) |
| 648 | return -ENOMEM; |
| 649 | |
| 650 | /* Set up network device as normal. */ |
| 651 | dev->netdev_ops = &virtnet_netdev; |
| 652 | dev->features = NETIF_F_HIGHDMA; |
| 653 | SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); |
| 654 | SET_NETDEV_DEV(dev, &vdev->dev); |
| 655 | |
| 656 | /* Do we support "hardware" checksums? */ |
| 657 | if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { |
| 658 | /* This opens up the world of extra features. */ |
| 659 | dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; |
| 660 | if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { |
| 661 | dev->features |= NETIF_F_TSO | NETIF_F_UFO |
| 662 | | NETIF_F_TSO_ECN | NETIF_F_TSO6; |
| 663 | } |
| 664 | /* Individual feature bits: what can host handle? */ |
| 665 | if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) |
| 666 | dev->features |= NETIF_F_TSO; |
| 667 | if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) |
| 668 | dev->features |= NETIF_F_TSO6; |
| 669 | if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) |
| 670 | dev->features |= NETIF_F_TSO_ECN; |
| 671 | if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) |
| 672 | dev->features |= NETIF_F_UFO; |
| 673 | } |
| 674 | |
| 675 | /* Configuration may specify what MAC to use. Otherwise random. */ |
| 676 | if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { |
| 677 | vdev->config->get(vdev, |
| 678 | offsetof(struct virtio_net_config, mac), |
| 679 | dev->dev_addr, dev->addr_len); |
| 680 | } else |
| 681 | random_ether_addr(dev->dev_addr); |
| 682 | |
| 683 | /* Set up our device-specific information */ |
| 684 | vi = netdev_priv(dev); |
| 685 | netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); |
| 686 | vi->dev = dev; |
| 687 | vi->vdev = vdev; |
| 688 | vdev->priv = vi; |
| 689 | vi->pages = NULL; |
| 690 | |
| 691 | /* If they give us a callback when all buffers are done, we don't need |
| 692 | * the timer. */ |
| 693 | vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY); |
| 694 | |
| 695 | /* If we can receive ANY GSO packets, we must allocate large ones. */ |
| 696 | if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) |
| 697 | || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) |
| 698 | || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) |
| 699 | vi->big_packets = true; |
| 700 | |
| 701 | if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) |
| 702 | vi->mergeable_rx_bufs = true; |
| 703 | |
| 704 | /* We expect two virtqueues, receive then send. */ |
| 705 | vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done); |
| 706 | if (IS_ERR(vi->rvq)) { |
| 707 | err = PTR_ERR(vi->rvq); |
| 708 | goto free; |
| 709 | } |
| 710 | |
| 711 | vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done); |
| 712 | if (IS_ERR(vi->svq)) { |
| 713 | err = PTR_ERR(vi->svq); |
| 714 | goto free_recv; |
| 715 | } |
| 716 | |
| 717 | /* Initialize our empty receive and send queues. */ |
| 718 | skb_queue_head_init(&vi->recv); |
| 719 | skb_queue_head_init(&vi->send); |
| 720 | |
| 721 | tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi); |
| 722 | |
| 723 | if (!vi->free_in_tasklet) |
| 724 | setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi); |
| 725 | |
| 726 | err = register_netdev(dev); |
| 727 | if (err) { |
| 728 | pr_debug("virtio_net: registering device failed\n"); |
| 729 | goto free_send; |
| 730 | } |
| 731 | |
| 732 | /* Last of all, set up some receive buffers. */ |
| 733 | try_fill_recv(vi); |
| 734 | |
| 735 | /* If we didn't even get one input buffer, we're useless. */ |
| 736 | if (vi->num == 0) { |
| 737 | err = -ENOMEM; |
| 738 | goto unregister; |
| 739 | } |
| 740 | |
| 741 | pr_debug("virtnet: registered device %s\n", dev->name); |
| 742 | return 0; |
| 743 | |
| 744 | unregister: |
| 745 | unregister_netdev(dev); |
| 746 | free_send: |
| 747 | vdev->config->del_vq(vi->svq); |
| 748 | free_recv: |
| 749 | vdev->config->del_vq(vi->rvq); |
| 750 | free: |
| 751 | free_netdev(dev); |
| 752 | return err; |
| 753 | } |
| 754 | |
| 755 | static void virtnet_remove(struct virtio_device *vdev) |
| 756 | { |
| 757 | struct virtnet_info *vi = vdev->priv; |
| 758 | struct sk_buff *skb; |
| 759 | |
| 760 | /* Stop all the virtqueues. */ |
| 761 | vdev->config->reset(vdev); |
| 762 | |
| 763 | if (!vi->free_in_tasklet) |
| 764 | del_timer_sync(&vi->xmit_free_timer); |
| 765 | |
| 766 | /* Free our skbs in send and recv queues, if any. */ |
| 767 | while ((skb = __skb_dequeue(&vi->recv)) != NULL) { |
| 768 | kfree_skb(skb); |
| 769 | vi->num--; |
| 770 | } |
| 771 | __skb_queue_purge(&vi->send); |
| 772 | |
| 773 | BUG_ON(vi->num != 0); |
| 774 | |
| 775 | vdev->config->del_vq(vi->svq); |
| 776 | vdev->config->del_vq(vi->rvq); |
| 777 | unregister_netdev(vi->dev); |
| 778 | |
| 779 | while (vi->pages) |
| 780 | __free_pages(get_a_page(vi, GFP_KERNEL), 0); |
| 781 | |
| 782 | free_netdev(vi->dev); |
| 783 | } |
| 784 | |
| 785 | static struct virtio_device_id id_table[] = { |
| 786 | { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, |
| 787 | { 0 }, |
| 788 | }; |
| 789 | |
| 790 | static unsigned int features[] = { |
| 791 | VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, |
| 792 | VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, |
| 793 | VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, |
| 794 | VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, |
| 795 | VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */ |
| 796 | VIRTIO_NET_F_MRG_RXBUF, |
| 797 | VIRTIO_F_NOTIFY_ON_EMPTY, |
| 798 | }; |
| 799 | |
| 800 | static struct virtio_driver virtio_net = { |
| 801 | .feature_table = features, |
| 802 | .feature_table_size = ARRAY_SIZE(features), |
| 803 | .driver.name = KBUILD_MODNAME, |
| 804 | .driver.owner = THIS_MODULE, |
| 805 | .id_table = id_table, |
| 806 | .probe = virtnet_probe, |
| 807 | .remove = __devexit_p(virtnet_remove), |
| 808 | }; |
| 809 | |
| 810 | static int __init init(void) |
| 811 | { |
| 812 | return register_virtio_driver(&virtio_net); |
| 813 | } |
| 814 | |
| 815 | static void __exit fini(void) |
| 816 | { |
| 817 | unregister_virtio_driver(&virtio_net); |
| 818 | } |
| 819 | module_init(init); |
| 820 | module_exit(fini); |
| 821 | |
| 822 | MODULE_DEVICE_TABLE(virtio, id_table); |
| 823 | MODULE_DESCRIPTION("Virtio network driver"); |
| 824 | MODULE_LICENSE("GPL"); |