arch/xtensa/platforms/iss/network.c

   1 /*
   2  *
   3  * arch/xtensa/platforms/iss/network.c
   4  *
   5  * Platform specific initialization.
   6  *
   7  * Authors: Chris Zankel <chris@zankel.net>
   8  * Based on work form the UML team.
   9  *
  10  * Copyright 2005 Tensilica Inc.
  11  *
  12  * This program is free software; you can redistribute  it and/or modify it
  13  * under  the terms of  the GNU General  Public License as published by the
  14  * Free Software Foundation;  either version 2 of the  License, or (at your
  15  * option) any later version.
  16  *
  17  */
  18
  19 #define pr_fmt(fmt) "%s: " fmt, __func__
  20
  21 #include <linux/list.h>
  22 #include <linux/irq.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/slab.h>
  25 #include <linux/timer.h>
  26 #include <linux/if_ether.h>
  27 #include <linux/inetdevice.h>
  28 #include <linux/init.h>
  29 #include <linux/if_tun.h>
  30 #include <linux/etherdevice.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/ioctl.h>
  33 #include <linux/bootmem.h>
  34 #include <linux/ethtool.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/platform_device.h>
  37
  38 #include <platform/simcall.h>
  39
  40 #define DRIVER_NAME "iss-netdev"
  41 #define ETH_MAX_PACKET 1500
  42 #define ETH_HEADER_OTHER 14
  43 #define ISS_NET_TIMER_VALUE (HZ / 10)
  44
  45
  46 static DEFINE_SPINLOCK(opened_lock);
  47 static LIST_HEAD(opened);
  48
  49 static DEFINE_SPINLOCK(devices_lock);
  50 static LIST_HEAD(devices);
  51
  52 /* ------------------------------------------------------------------------- */
  53
  54 /* We currently only support the TUNTAP transport protocol. */
  55
  56 #define TRANSPORT_TUNTAP_NAME "tuntap"
  57 #define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET
  58
  59 struct tuntap_info {
  60         char dev_name[IFNAMSIZ];
  61         int fd;
  62 };
  63
  64 /* ------------------------------------------------------------------------- */
  65
  66
  67 /* This structure contains out private information for the driver. */
  68
  69 struct iss_net_private {
  70         struct list_head device_list;
  71         struct list_head opened_list;
  72
  73         spinlock_t lock;
  74         struct net_device *dev;
  75         struct platform_device pdev;
  76         struct timer_list tl;
  77         struct net_device_stats stats;
  78
  79         struct timer_list timer;
  80         unsigned int timer_val;
  81
  82         int index;
  83         int mtu;
  84
  85         struct {
  86                 union {
  87                         struct tuntap_info tuntap;
  88                 } info;
  89
  90                 int (*open)(struct iss_net_private *lp);
  91                 void (*close)(struct iss_net_private *lp);
  92                 int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
  93                 int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
  94                 unsigned short (*protocol)(struct sk_buff *skb);
  95                 int (*poll)(struct iss_net_private *lp);
  96         } tp;
  97
  98 };
  99
 100 /* ================================ HELPERS ================================ */
 101
 102
 103 static char *split_if_spec(char *str, ...)
 104 {
 105         char **arg, *end;
 106         va_list ap;
 107
 108         va_start(ap, str);
 109         while ((arg = va_arg(ap, char**)) != NULL) {
 110                 if (*str == '\0') {
 111                         va_end(ap);
 112                         return NULL;
 113                 }
 114                 end = strchr(str, ',');
 115                 if (end != str)
 116                         *arg = str;
 117                 if (end == NULL) {
 118                         va_end(ap);
 119                         return NULL;
 120                 }
 121                 *end++ = '\0';
 122                 str = end;
 123         }
 124         va_end(ap);
 125         return str;
 126 }
 127
 128 /* Set Ethernet address of the specified device. */
 129
 130 static void setup_etheraddr(struct net_device *dev, char *str)
 131 {
 132         unsigned char *addr = dev->dev_addr;
 133
 134         if (str == NULL)
 135                 goto random;
 136
 137         if (!mac_pton(str, addr)) {
 138                 pr_err("%s: failed to parse '%s' as an ethernet address\n",
 139                        dev->name, str);
 140                 goto random;
 141         }
 142         if (is_multicast_ether_addr(addr)) {
 143                 pr_err("%s: attempt to assign a multicast ethernet address\n",
 144                        dev->name);
 145                 goto random;
 146         }
 147         if (!is_valid_ether_addr(addr)) {
 148                 pr_err("%s: attempt to assign an invalid ethernet address\n",
 149                        dev->name);
 150                 goto random;
 151         }
 152         if (!is_local_ether_addr(addr))
 153                 pr_warn("%s: assigning a globally valid ethernet address\n",
 154                         dev->name);
 155         return;
 156
 157 random:
 158         pr_info("%s: choosing a random ethernet address\n",
 159                 dev->name);
 160         eth_hw_addr_random(dev);
 161 }
 162
 163 /* ======================= TUNTAP TRANSPORT INTERFACE ====================== */
 164
 165 static int tuntap_open(struct iss_net_private *lp)
 166 {
 167         struct ifreq ifr;
 168         char *dev_name = lp->tp.info.tuntap.dev_name;
 169         int err = -EINVAL;
 170         int fd;
 171
 172         fd = simc_open("/dev/net/tun", 02, 0); /* O_RDWR */
 173         if (fd < 0) {
 174                 pr_err("%s: failed to open /dev/net/tun, returned %d (errno = %d)\n",
 175                        lp->dev->name, fd, errno);
 176                 return fd;
 177         }
 178
 179         memset(&ifr, 0, sizeof(ifr));
 180         ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
 181         strlcpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
 182
 183         err = simc_ioctl(fd, TUNSETIFF, &ifr);
 184         if (err < 0) {
 185                 pr_err("%s: failed to set interface %s, returned %d (errno = %d)\n",
 186                        lp->dev->name, dev_name, err, errno);
 187                 simc_close(fd);
 188                 return err;
 189         }
 190
 191         lp->tp.info.tuntap.fd = fd;
 192         return err;
 193 }
 194
 195 static void tuntap_close(struct iss_net_private *lp)
 196 {
 197         simc_close(lp->tp.info.tuntap.fd);
 198         lp->tp.info.tuntap.fd = -1;
 199 }
 200
 201 static int tuntap_read(struct iss_net_private *lp, struct sk_buff **skb)
 202 {
 203         return simc_read(lp->tp.info.tuntap.fd,
 204                         (*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
 205 }
 206
 207 static int tuntap_write(struct iss_net_private *lp, struct sk_buff **skb)
 208 {
 209         return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
 210 }
 211
 212 unsigned short tuntap_protocol(struct sk_buff *skb)
 213 {
 214         return eth_type_trans(skb, skb->dev);
 215 }
 216
 217 static int tuntap_poll(struct iss_net_private *lp)
 218 {
 219         return simc_poll(lp->tp.info.tuntap.fd);
 220 }
 221
 222 /*
 223  * ethX=tuntap,[mac address],device name
 224  */
 225
 226 static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
 227 {
 228         struct net_device *dev = lp->dev;
 229         char *dev_name = NULL, *mac_str = NULL, *rem = NULL;
 230
 231         /* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */
 232
 233         if (strncmp(init, TRANSPORT_TUNTAP_NAME,
 234                     sizeof(TRANSPORT_TUNTAP_NAME) - 1))
 235                 return 0;
 236
 237         init += sizeof(TRANSPORT_TUNTAP_NAME) - 1;
 238         if (*init == ',') {
 239                 rem = split_if_spec(init + 1, &mac_str, &dev_name);
 240                 if (rem != NULL) {
 241                         pr_err("%s: extra garbage on specification : '%s'\n",
 242                                dev->name, rem);
 243                         return 0;
 244                 }
 245         } else if (*init != '\0') {
 246                 pr_err("%s: invalid argument: %s. Skipping device!\n",
 247                        dev->name, init);
 248                 return 0;
 249         }
 250
 251         if (!dev_name) {
 252                 pr_err("%s: missing tuntap device name\n", dev->name);
 253                 return 0;
 254         }
 255
 256         strlcpy(lp->tp.info.tuntap.dev_name, dev_name,
 257                 sizeof(lp->tp.info.tuntap.dev_name));
 258
 259         setup_etheraddr(dev, mac_str);
 260
 261         lp->mtu = TRANSPORT_TUNTAP_MTU;
 262
 263         lp->tp.info.tuntap.fd = -1;
 264
 265         lp->tp.open = tuntap_open;
 266         lp->tp.close = tuntap_close;
 267         lp->tp.read = tuntap_read;
 268         lp->tp.write = tuntap_write;
 269         lp->tp.protocol = tuntap_protocol;
 270         lp->tp.poll = tuntap_poll;
 271
 272         return 1;
 273 }
 274
 275 /* ================================ ISS NET ================================ */
 276
 277 static int iss_net_rx(struct net_device *dev)
 278 {
 279         struct iss_net_private *lp = netdev_priv(dev);
 280         int pkt_len;
 281         struct sk_buff *skb;
 282
 283         /* Check if there is any new data. */
 284
 285         if (lp->tp.poll(lp) == 0)
 286                 return 0;
 287
 288         /* Try to allocate memory, if it fails, try again next round. */
 289
 290         skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER);
 291         if (skb == NULL) {
 292                 lp->stats.rx_dropped++;
 293                 return 0;
 294         }
 295
 296         skb_reserve(skb, 2);
 297
 298         /* Setup skb */
 299
 300         skb->dev = dev;
 301         skb_reset_mac_header(skb);
 302         pkt_len = lp->tp.read(lp, &skb);
 303         skb_put(skb, pkt_len);
 304
 305         if (pkt_len > 0) {
 306                 skb_trim(skb, pkt_len);
 307                 skb->protocol = lp->tp.protocol(skb);
 308
 309                 lp->stats.rx_bytes += skb->len;
 310                 lp->stats.rx_packets++;
 311                 netif_rx_ni(skb);
 312                 return pkt_len;
 313         }
 314         kfree_skb(skb);
 315         return pkt_len;
 316 }
 317
 318 static int iss_net_poll(void)
 319 {
 320         struct list_head *ele;
 321         int err, ret = 0;
 322
 323         spin_lock(&opened_lock);
 324
 325         list_for_each(ele, &opened) {
 326                 struct iss_net_private *lp;
 327
 328                 lp = list_entry(ele, struct iss_net_private, opened_list);
 329
 330                 if (!netif_running(lp->dev))
 331                         break;
 332
 333                 spin_lock(&lp->lock);
 334
 335                 while ((err = iss_net_rx(lp->dev)) > 0)
 336                         ret++;
 337
 338                 spin_unlock(&lp->lock);
 339
 340                 if (err < 0) {
 341                         pr_err("Device '%s' read returned %d, shutting it down\n",
 342                                lp->dev->name, err);
 343                         dev_close(lp->dev);
 344                 } else {
 345                         /* FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ); */
 346                 }
 347         }
 348
 349         spin_unlock(&opened_lock);
 350         return ret;
 351 }
 352
 353
 354 static void iss_net_timer(struct timer_list *t)
 355 {
 356         struct iss_net_private *lp = from_timer(lp, t, timer);
 357
 358         iss_net_poll();
 359         spin_lock(&lp->lock);
 360         mod_timer(&lp->timer, jiffies + lp->timer_val);
 361         spin_unlock(&lp->lock);
 362 }
 363
 364
 365 static int iss_net_open(struct net_device *dev)
 366 {
 367         struct iss_net_private *lp = netdev_priv(dev);
 368         int err;
 369
 370         spin_lock_bh(&lp->lock);
 371
 372         err = lp->tp.open(lp);
 373         if (err < 0)
 374                 goto out;
 375
 376         netif_start_queue(dev);
 377
 378         /* clear buffer - it can happen that the host side of the interface
 379          * is full when we get here. In this case, new data is never queued,
 380          * SIGIOs never arrive, and the net never works.
 381          */
 382         while ((err = iss_net_rx(dev)) > 0)
 383                 ;
 384
 385         spin_unlock_bh(&lp->lock);
 386         spin_lock_bh(&opened_lock);
 387         list_add(&lp->opened_list, &opened);
 388         spin_unlock_bh(&opened_lock);
 389         spin_lock_bh(&lp->lock);
 390
 391         timer_setup(&lp->timer, iss_net_timer, 0);
 392         lp->timer_val = ISS_NET_TIMER_VALUE;
 393         mod_timer(&lp->timer, jiffies + lp->timer_val);
 394
 395 out:
 396         spin_unlock_bh(&lp->lock);
 397         return err;
 398 }
 399
 400 static int iss_net_close(struct net_device *dev)
 401 {
 402         struct iss_net_private *lp = netdev_priv(dev);
 403         netif_stop_queue(dev);
 404         spin_lock_bh(&lp->lock);
 405
 406         spin_lock(&opened_lock);
 407         list_del(&opened);
 408         spin_unlock(&opened_lock);
 409
 410         del_timer_sync(&lp->timer);
 411
 412         lp->tp.close(lp);
 413
 414         spin_unlock_bh(&lp->lock);
 415         return 0;
 416 }
 417
 418 static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 419 {
 420         struct iss_net_private *lp = netdev_priv(dev);
 421         int len;
 422
 423         netif_stop_queue(dev);
 424         spin_lock_bh(&lp->lock);
 425
 426         len = lp->tp.write(lp, &skb);
 427
 428         if (len == skb->len) {
 429                 lp->stats.tx_packets++;
 430                 lp->stats.tx_bytes += skb->len;
 431                 netif_trans_update(dev);
 432                 netif_start_queue(dev);
 433
 434                 /* this is normally done in the interrupt when tx finishes */
 435                 netif_wake_queue(dev);
 436
 437         } else if (len == 0) {
 438                 netif_start_queue(dev);
 439                 lp->stats.tx_dropped++;
 440
 441         } else {
 442                 netif_start_queue(dev);
 443                 pr_err("%s: %s failed(%d)\n", dev->name, __func__, len);
 444         }
 445
 446         spin_unlock_bh(&lp->lock);
 447
 448         dev_kfree_skb(skb);
 449         return NETDEV_TX_OK;
 450 }
 451
 452
 453 static struct net_device_stats *iss_net_get_stats(struct net_device *dev)
 454 {
 455         struct iss_net_private *lp = netdev_priv(dev);
 456         return &lp->stats;
 457 }
 458
 459 static void iss_net_set_multicast_list(struct net_device *dev)
 460 {
 461 }
 462
 463 static void iss_net_tx_timeout(struct net_device *dev)
 464 {
 465 }
 466
 467 static int iss_net_set_mac(struct net_device *dev, void *addr)
 468 {
 469         struct iss_net_private *lp = netdev_priv(dev);
 470         struct sockaddr *hwaddr = addr;
 471
 472         if (!is_valid_ether_addr(hwaddr->sa_data))
 473                 return -EADDRNOTAVAIL;
 474         spin_lock_bh(&lp->lock);
 475         memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
 476         spin_unlock_bh(&lp->lock);
 477         return 0;
 478 }
 479
 480 static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
 481 {
 482         return -EINVAL;
 483 }
 484
 485 void iss_net_user_timer_expire(struct timer_list *unused)
 486 {
 487 }
 488
 489
 490 static struct platform_driver iss_net_driver = {
 491         .driver = {
 492                 .name  = DRIVER_NAME,
 493         },
 494 };
 495
 496 static int driver_registered;
 497
 498 static const struct net_device_ops iss_netdev_ops = {
 499         .ndo_open               = iss_net_open,
 500         .ndo_stop               = iss_net_close,
 501         .ndo_get_stats          = iss_net_get_stats,
 502         .ndo_start_xmit         = iss_net_start_xmit,
 503         .ndo_validate_addr      = eth_validate_addr,
 504         .ndo_change_mtu         = iss_net_change_mtu,
 505         .ndo_set_mac_address    = iss_net_set_mac,
 506         .ndo_tx_timeout         = iss_net_tx_timeout,
 507         .ndo_set_rx_mode        = iss_net_set_multicast_list,
 508 };
 509
 510 static int iss_net_configure(int index, char *init)
 511 {
 512         struct net_device *dev;
 513         struct iss_net_private *lp;
 514         int err;
 515
 516         dev = alloc_etherdev(sizeof(*lp));
 517         if (dev == NULL) {
 518                 pr_err("eth_configure: failed to allocate device\n");
 519                 return 1;
 520         }
 521
 522         /* Initialize private element. */
 523
 524         lp = netdev_priv(dev);
 525         *lp = (struct iss_net_private) {
 526                 .device_list            = LIST_HEAD_INIT(lp->device_list),
 527                 .opened_list            = LIST_HEAD_INIT(lp->opened_list),
 528                 .dev                    = dev,
 529                 .index                  = index,
 530         };
 531
 532         spin_lock_init(&lp->lock);
 533         /*
 534          * If this name ends up conflicting with an existing registered
 535          * netdevice, that is OK, register_netdev{,ice}() will notice this
 536          * and fail.
 537          */
 538         snprintf(dev->name, sizeof(dev->name), "eth%d", index);
 539
 540         /*
 541          * Try all transport protocols.
 542          * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
 543          */
 544
 545         if (!tuntap_probe(lp, index, init)) {
 546                 pr_err("%s: invalid arguments. Skipping device!\n",
 547                        dev->name);
 548                 goto errout;
 549         }
 550
 551         pr_info("Netdevice %d (%pM)\n", index, dev->dev_addr);
 552
 553         /* sysfs register */
 554
 555         if (!driver_registered) {
 556                 platform_driver_register(&iss_net_driver);
 557                 driver_registered = 1;
 558         }
 559
 560         spin_lock(&devices_lock);
 561         list_add(&lp->device_list, &devices);
 562         spin_unlock(&devices_lock);
 563
 564         lp->pdev.id = index;
 565         lp->pdev.name = DRIVER_NAME;
 566         platform_device_register(&lp->pdev);
 567         SET_NETDEV_DEV(dev, &lp->pdev.dev);
 568
 569         dev->netdev_ops = &iss_netdev_ops;
 570         dev->mtu = lp->mtu;
 571         dev->watchdog_timeo = (HZ >> 1);
 572         dev->irq = -1;
 573
 574         rtnl_lock();
 575         err = register_netdevice(dev);
 576         rtnl_unlock();
 577
 578         if (err) {
 579                 pr_err("%s: error registering net device!\n", dev->name);
 580                 /* XXX: should we call ->remove() here? */
 581                 free_netdev(dev);
 582                 return 1;
 583         }
 584
 585         timer_setup(&lp->tl, iss_net_user_timer_expire, 0);
 586
 587         return 0;
 588
 589 errout:
 590         /* FIXME: unregister; free, etc.. */
 591         return -EIO;
 592 }
 593
 594 /* ------------------------------------------------------------------------- */
 595
 596 /* Filled in during early boot */
 597
 598 struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
 599
 600 struct iss_net_init {
 601         struct list_head list;
 602         char *init;             /* init string */
 603         int index;
 604 };
 605
 606 /*
 607  * Parse the command line and look for 'ethX=...' fields, and register all
 608  * those fields. They will be later initialized in iss_net_init.
 609  */
 610
 611 static int __init iss_net_setup(char *str)
 612 {
 613         struct iss_net_private *device = NULL;
 614         struct iss_net_init *new;
 615         struct list_head *ele;
 616         char *end;
 617         int rc;
 618         unsigned n;
 619
 620         end = strchr(str, '=');
 621         if (!end) {
 622                 pr_err("Expected '=' after device number\n");
 623                 return 1;
 624         }
 625         *end = 0;
 626         rc = kstrtouint(str, 0, &n);
 627         *end = '=';
 628         if (rc < 0) {
 629                 pr_err("Failed to parse '%s'\n", str);
 630                 return 1;
 631         }
 632         str = end;
 633
 634         spin_lock(&devices_lock);
 635
 636         list_for_each(ele, &devices) {
 637                 device = list_entry(ele, struct iss_net_private, device_list);
 638                 if (device->index == n)
 639                         break;
 640         }
 641
 642         spin_unlock(&devices_lock);
 643
 644         if (device && device->index == n) {
 645                 pr_err("Device %u already configured\n", n);
 646                 return 1;
 647         }
 648
 649         new = alloc_bootmem(sizeof(*new));
 650         if (new == NULL) {
 651                 pr_err("Alloc_bootmem failed\n");
 652                 return 1;
 653         }
 654
 655         INIT_LIST_HEAD(&new->list);
 656         new->index = n;
 657         new->init = str + 1;
 658
 659         list_add_tail(&new->list, &eth_cmd_line);
 660         return 1;
 661 }
 662
 663 __setup("eth", iss_net_setup);
 664
 665 /*
 666  * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
 667  */
 668
 669 static int iss_net_init(void)
 670 {
 671         struct list_head *ele, *next;
 672
 673         /* Walk through all Ethernet devices specified in the command line. */
 674
 675         list_for_each_safe(ele, next, &eth_cmd_line) {
 676                 struct iss_net_init *eth;
 677                 eth = list_entry(ele, struct iss_net_init, list);
 678                 iss_net_configure(eth->index, eth->init);
 679         }
 680
 681         return 1;
 682 }
 683 device_initcall(iss_net_init);