drivers/staging/hv/netvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/init.h>
  24 #include <linux/atomic.h>
  25 #include <linux/module.h>
  26 #include <linux/highmem.h>
  27 #include <linux/device.h>
  28 #include <linux/io.h>
  29 #include <linux/delay.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/inetdevice.h>
  32 #include <linux/etherdevice.h>
  33 #include <linux/skbuff.h>
  34 #include <linux/in.h>
  35 #include <linux/slab.h>
  36 #include <net/arp.h>
  37 #include <net/route.h>
  38 #include <net/sock.h>
  39 #include <net/pkt_sched.h>
  40
  41 #include "hyperv_net.h"
  42
  43 struct net_device_context {
  44         /* point back to our device context */
  45         struct hv_device *device_ctx;
  46         atomic_t avail;
  47         struct delayed_work dwork;
  48 };
  49
  50
  51 #define PACKET_PAGES_LOWATER  8
  52 /* Need this many pages to handle worst case fragmented packet */
  53 #define PACKET_PAGES_HIWATER  (MAX_SKB_FRAGS + 2)
  54
  55 static int ring_size = 128;
  56 module_param(ring_size, int, S_IRUGO);
  57 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
  58
  59 /* no-op so the netdev core doesn't return -EINVAL when modifying the the
  60  * multicast address list in SIOCADDMULTI. hv is setup to get all multicast
  61  * when it calls RndisFilterOnOpen() */
  62 static void netvsc_set_multicast_list(struct net_device *net)
  63 {
  64 }
  65
  66 static int netvsc_open(struct net_device *net)
  67 {
  68         struct net_device_context *net_device_ctx = netdev_priv(net);
  69         struct hv_device *device_obj = net_device_ctx->device_ctx;
  70         int ret = 0;
  71
  72         if (netif_carrier_ok(net)) {
  73                 /* Open up the device */
  74                 ret = rndis_filter_open(device_obj);
  75                 if (ret != 0) {
  76                         netdev_err(net, "unable to open device (ret %d).\n",
  77                                    ret);
  78                         return ret;
  79                 }
  80
  81                 netif_start_queue(net);
  82         } else {
  83                 netdev_err(net, "unable to open device...link is down.\n");
  84         }
  85
  86         return ret;
  87 }
  88
  89 static int netvsc_close(struct net_device *net)
  90 {
  91         struct net_device_context *net_device_ctx = netdev_priv(net);
  92         struct hv_device *device_obj = net_device_ctx->device_ctx;
  93         int ret;
  94
  95         netif_stop_queue(net);
  96
  97         ret = rndis_filter_close(device_obj);
  98         if (ret != 0)
  99                 netdev_err(net, "unable to close device (ret %d).\n", ret);
 100
 101         return ret;
 102 }
 103
 104 static void netvsc_xmit_completion(void *context)
 105 {
 106         struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
 107         struct sk_buff *skb = (struct sk_buff *)
 108                 (unsigned long)packet->completion.send.send_completion_tid;
 109
 110         kfree(packet);
 111
 112         if (skb) {
 113                 struct net_device *net = skb->dev;
 114                 struct net_device_context *net_device_ctx = netdev_priv(net);
 115                 unsigned int num_pages = skb_shinfo(skb)->nr_frags + 2;
 116
 117                 dev_kfree_skb_any(skb);
 118
 119                 atomic_add(num_pages, &net_device_ctx->avail);
 120                 if (atomic_read(&net_device_ctx->avail) >=
 121                                 PACKET_PAGES_HIWATER)
 122                         netif_wake_queue(net);
 123         }
 124 }
 125
 126 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 127 {
 128         struct net_device_context *net_device_ctx = netdev_priv(net);
 129         struct hv_netvsc_packet *packet;
 130         int ret;
 131         unsigned int i, num_pages;
 132
 133         /* Add 1 for skb->data and additional one for RNDIS */
 134         num_pages = skb_shinfo(skb)->nr_frags + 1 + 1;
 135         if (num_pages > atomic_read(&net_device_ctx->avail))
 136                 return NETDEV_TX_BUSY;
 137
 138         /* Allocate a netvsc packet based on # of frags. */
 139         packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 140                          (num_pages * sizeof(struct hv_page_buffer)) +
 141                          sizeof(struct rndis_filter_packet), GFP_ATOMIC);
 142         if (!packet) {
 143                 /* out of memory, silently drop packet */
 144                 netdev_err(net, "unable to allocate hv_netvsc_packet\n");
 145
 146                 dev_kfree_skb(skb);
 147                 net->stats.tx_dropped++;
 148                 return NETDEV_TX_OK;
 149         }
 150
 151         packet->extension = (void *)(unsigned long)packet +
 152                                 sizeof(struct hv_netvsc_packet) +
 153                                     (num_pages * sizeof(struct hv_page_buffer));
 154
 155         /* Setup the rndis header */
 156         packet->page_buf_cnt = num_pages;
 157
 158         /* Initialize it from the skb */
 159         packet->total_data_buflen       = skb->len;
 160
 161         /* Start filling in the page buffers starting after RNDIS buffer. */
 162         packet->page_buf[1].pfn = virt_to_phys(skb->data) >> PAGE_SHIFT;
 163         packet->page_buf[1].offset
 164                 = (unsigned long)skb->data & (PAGE_SIZE - 1);
 165         packet->page_buf[1].len = skb_headlen(skb);
 166
 167         /* Additional fragments are after SKB data */
 168         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 169                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
 170
 171                 packet->page_buf[i+2].pfn = page_to_pfn(f->page);
 172                 packet->page_buf[i+2].offset = f->page_offset;
 173                 packet->page_buf[i+2].len = f->size;
 174         }
 175
 176         /* Set the completion routine */
 177         packet->completion.send.send_completion = netvsc_xmit_completion;
 178         packet->completion.send.send_completion_ctx = packet;
 179         packet->completion.send.send_completion_tid = (unsigned long)skb;
 180
 181         ret = rndis_filter_send(net_device_ctx->device_ctx,
 182                                   packet);
 183         if (ret == 0) {
 184                 net->stats.tx_bytes += skb->len;
 185                 net->stats.tx_packets++;
 186
 187                 atomic_sub(num_pages, &net_device_ctx->avail);
 188                 if (atomic_read(&net_device_ctx->avail) < PACKET_PAGES_LOWATER)
 189                         netif_stop_queue(net);
 190         } else {
 191                 /* we are shutting down or bus overloaded, just drop packet */
 192                 net->stats.tx_dropped++;
 193                 netvsc_xmit_completion(packet);
 194         }
 195
 196         return NETDEV_TX_OK;
 197 }
 198
 199 /*
 200  * netvsc_linkstatus_callback - Link up/down notification
 201  */
 202 void netvsc_linkstatus_callback(struct hv_device *device_obj,
 203                                        unsigned int status)
 204 {
 205         struct net_device *net = dev_get_drvdata(&device_obj->device);
 206         struct net_device_context *ndev_ctx;
 207
 208         if (!net) {
 209                 netdev_err(net, "got link status but net device "
 210                                 "not initialized yet\n");
 211                 return;
 212         }
 213
 214         if (status == 1) {
 215                 netif_carrier_on(net);
 216                 netif_wake_queue(net);
 217                 ndev_ctx = netdev_priv(net);
 218                 schedule_delayed_work(&ndev_ctx->dwork, 0);
 219                 schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
 220         } else {
 221                 netif_carrier_off(net);
 222                 netif_stop_queue(net);
 223         }
 224 }
 225
 226 /*
 227  * netvsc_recv_callback -  Callback when we receive a packet from the
 228  * "wire" on the specified device.
 229  */
 230 int netvsc_recv_callback(struct hv_device *device_obj,
 231                                 struct hv_netvsc_packet *packet)
 232 {
 233         struct net_device *net = dev_get_drvdata(&device_obj->device);
 234         struct sk_buff *skb;
 235         void *data;
 236         int i;
 237         unsigned long flags;
 238
 239         if (!net) {
 240                 netdev_err(net, "got receive callback but net device"
 241                         " not initialized yet\n");
 242                 return 0;
 243         }
 244
 245         /* Allocate a skb - TODO direct I/O to pages? */
 246         skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen);
 247         if (unlikely(!skb)) {
 248                 ++net->stats.rx_dropped;
 249                 return 0;
 250         }
 251
 252         /* for kmap_atomic */
 253         local_irq_save(flags);
 254
 255         /*
 256          * Copy to skb. This copy is needed here since the memory pointed by
 257          * hv_netvsc_packet cannot be deallocated
 258          */
 259         for (i = 0; i < packet->page_buf_cnt; i++) {
 260                 data = kmap_atomic(pfn_to_page(packet->page_buf[i].pfn),
 261                                                KM_IRQ1);
 262                 data = (void *)(unsigned long)data +
 263                                 packet->page_buf[i].offset;
 264
 265                 memcpy(skb_put(skb, packet->page_buf[i].len), data,
 266                        packet->page_buf[i].len);
 267
 268                 kunmap_atomic((void *)((unsigned long)data -
 269                                        packet->page_buf[i].offset), KM_IRQ1);
 270         }
 271
 272         local_irq_restore(flags);
 273
 274         skb->protocol = eth_type_trans(skb, net);
 275         skb->ip_summed = CHECKSUM_NONE;
 276
 277         net->stats.rx_packets++;
 278         net->stats.rx_bytes += skb->len;
 279
 280         /*
 281          * Pass the skb back up. Network stack will deallocate the skb when it
 282          * is done.
 283          * TODO - use NAPI?
 284          */
 285         netif_rx(skb);
 286
 287         return 0;
 288 }
 289
 290 static void netvsc_get_drvinfo(struct net_device *net,
 291                                struct ethtool_drvinfo *info)
 292 {
 293         strcpy(info->driver, "hv_netvsc");
 294         strcpy(info->version, HV_DRV_VERSION);
 295         strcpy(info->fw_version, "N/A");
 296 }
 297
 298 static const struct ethtool_ops ethtool_ops = {
 299         .get_drvinfo    = netvsc_get_drvinfo,
 300         .get_link       = ethtool_op_get_link,
 301 };
 302
 303 static const struct net_device_ops device_ops = {
 304         .ndo_open =                     netvsc_open,
 305         .ndo_stop =                     netvsc_close,
 306         .ndo_start_xmit =               netvsc_start_xmit,
 307         .ndo_set_multicast_list =       netvsc_set_multicast_list,
 308         .ndo_change_mtu =               eth_change_mtu,
 309         .ndo_validate_addr =            eth_validate_addr,
 310         .ndo_set_mac_address =          eth_mac_addr,
 311 };
 312
 313 /*
 314  * Send GARP packet to network peers after migrations.
 315  * After Quick Migration, the network is not immediately operational in the
 316  * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
 317  * another netif_notify_peers() into a delayed work, otherwise GARP packet
 318  * will not be sent after quick migration, and cause network disconnection.
 319  */
 320 static void netvsc_send_garp(struct work_struct *w)
 321 {
 322         struct net_device_context *ndev_ctx;
 323         struct net_device *net;
 324
 325         ndev_ctx = container_of(w, struct net_device_context, dwork.work);
 326         net = dev_get_drvdata(&ndev_ctx->device_ctx->device);
 327         netif_notify_peers(net);
 328 }
 329
 330
 331 static int netvsc_probe(struct hv_device *dev)
 332 {
 333         struct net_device *net = NULL;
 334         struct net_device_context *net_device_ctx;
 335         struct netvsc_device_info device_info;
 336         int ret;
 337
 338         net = alloc_etherdev(sizeof(struct net_device_context));
 339         if (!net)
 340                 return -ENOMEM;
 341
 342         /* Set initial state */
 343         netif_carrier_off(net);
 344
 345         net_device_ctx = netdev_priv(net);
 346         net_device_ctx->device_ctx = dev;
 347         atomic_set(&net_device_ctx->avail, ring_size);
 348         dev_set_drvdata(&dev->device, net);
 349         INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_send_garp);
 350
 351         /* Notify the netvsc driver of the new device */
 352         device_info.ring_size = ring_size;
 353         ret = rndis_filter_device_add(dev, &device_info);
 354         if (ret != 0) {
 355                 free_netdev(net);
 356                 dev_set_drvdata(&dev->device, NULL);
 357                 return ret;
 358         }
 359
 360         netif_carrier_on(net);
 361
 362         memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
 363
 364         net->netdev_ops = &device_ops;
 365
 366         /* TODO: Add GSO and Checksum offload */
 367         net->hw_features = NETIF_F_SG;
 368         net->features = NETIF_F_SG;
 369
 370         SET_ETHTOOL_OPS(net, &ethtool_ops);
 371         SET_NETDEV_DEV(net, &dev->device);
 372
 373         ret = register_netdev(net);
 374         if (ret != 0) {
 375                 /* Remove the device and release the resource */
 376                 rndis_filter_device_remove(dev);
 377                 free_netdev(net);
 378         }
 379
 380         return ret;
 381 }
 382
 383 static int netvsc_remove(struct hv_device *dev)
 384 {
 385         struct net_device *net = dev_get_drvdata(&dev->device);
 386         struct net_device_context *ndev_ctx;
 387
 388         if (net == NULL) {
 389                 dev_err(&dev->device, "No net device to remove\n");
 390                 return 0;
 391         }
 392
 393         ndev_ctx = netdev_priv(net);
 394         cancel_delayed_work_sync(&ndev_ctx->dwork);
 395
 396         /* Stop outbound asap */
 397         netif_stop_queue(net);
 398
 399         unregister_netdev(net);
 400
 401         /*
 402          * Call to the vsc driver to let it know that the device is being
 403          * removed
 404          */
 405         rndis_filter_device_remove(dev);
 406
 407         free_netdev(net);
 408         return 0;
 409 }
 410
 411 static const struct hv_vmbus_device_id id_table[] = {
 412         /* Network guid */
 413         { VMBUS_DEVICE(0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46,
 414                        0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E) },
 415         { },
 416 };
 417
 418 MODULE_DEVICE_TABLE(vmbus, id_table);
 419
 420 /* The one and only one */
 421 static struct  hv_driver netvsc_drv = {
 422         .name = "netvsc",
 423         .id_table = id_table,
 424         .probe = netvsc_probe,
 425         .remove = netvsc_remove,
 426 };
 427
 428 static void __exit netvsc_drv_exit(void)
 429 {
 430         vmbus_driver_unregister(&netvsc_drv);
 431 }
 432
 433 static int __init netvsc_drv_init(void)
 434 {
 435         return vmbus_driver_register(&netvsc_drv);
 436 }
 437
 438 MODULE_LICENSE("GPL");
 439 MODULE_VERSION(HV_DRV_VERSION);
 440 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
 441
 442 module_init(netvsc_drv_init);
 443 module_exit(netvsc_drv_exit);