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 #include <linux/list.h>
  20 #include <linux/irq.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/slab.h>
  23 #include <linux/timer.h>
  24 #include <linux/if_ether.h>
  25 #include <linux/inetdevice.h>
  26 #include <linux/init.h>
  27 #include <linux/if_tun.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/ioctl.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/ethtool.h>
  33 #include <linux/rtnetlink.h>
  34 #include <linux/platform_device.h>
  35
  36 #include <platform/simcall.h>
  37
  38 #define DRIVER_NAME "iss-netdev"
  39 #define ETH_MAX_PACKET 1500
  40 #define ETH_HEADER_OTHER 14
  41 #define ISS_NET_TIMER_VALUE (HZ / 10)
  42
  43
  44 static DEFINE_SPINLOCK(opened_lock);
  45 static LIST_HEAD(opened);
  46
  47 static DEFINE_SPINLOCK(devices_lock);
  48 static LIST_HEAD(devices);
  49
  50 /* ------------------------------------------------------------------------- */
  51
  52 /* We currently only support the TUNTAP transport protocol. */
  53
  54 #define TRANSPORT_TUNTAP_NAME "tuntap"
  55 #define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET
  56
  57 struct tuntap_info {
  58         char dev_name[IFNAMSIZ];
  59         int fd;
  60 };
  61
  62 /* ------------------------------------------------------------------------- */
  63
  64
  65 /* This structure contains out private information for the driver. */
  66
  67 struct iss_net_private {
  68         struct list_head device_list;
  69         struct list_head opened_list;
  70
  71         spinlock_t lock;
  72         struct net_device *dev;
  73         struct platform_device pdev;
  74         struct timer_list tl;
  75         struct net_device_stats stats;
  76
  77         struct timer_list timer;
  78         unsigned int timer_val;
  79
  80         int index;
  81         int mtu;
  82
  83         struct {
  84                 union {
  85                         struct tuntap_info tuntap;
  86                 } info;
  87
  88                 int (*open)(struct iss_net_private *lp);
  89                 void (*close)(struct iss_net_private *lp);
  90                 int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
  91                 int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
  92                 unsigned short (*protocol)(struct sk_buff *skb);
  93                 int (*poll)(struct iss_net_private *lp);
  94         } tp;
  95
  96 };
  97
  98 /* ================================ HELPERS ================================ */
  99
 100
 101 static char *split_if_spec(char *str, ...)
 102 {
 103         char **arg, *end;
 104         va_list ap;
 105
 106         va_start(ap, str);
 107         while ((arg = va_arg(ap, char**)) != NULL) {
 108                 if (*str == '\0') {
 109                         va_end(ap);
 110                         return NULL;
 111                 }
 112                 end = strchr(str, ',');
 113                 if (end != str)
 114                         *arg = str;
 115                 if (end == NULL) {
 116                         va_end(ap);
 117                         return NULL;
 118                 }
 119                 *end++ = '\0';
 120                 str = end;
 121         }
 122         va_end(ap);
 123         return str;
 124 }
 125
 126 /* Set Ethernet address of the specified device. */
 127
 128 static void setup_etheraddr(struct net_device *dev, char *str)
 129 {
 130         unsigned char *addr = dev->dev_addr;
 131
 132         if (str == NULL)
 133                 goto random;
 134
 135         if (!mac_pton(str, addr)) {
 136                 pr_err("%s: failed to parse '%s' as an ethernet address\n",
 137                        dev->name, str);
 138                 goto random;
 139         }
 140         if (is_multicast_ether_addr(addr)) {
 141                 pr_err("%s: attempt to assign a multicast ethernet address\n",
 142                        dev->name);
 143                 goto random;
 144         }
 145         if (!is_valid_ether_addr(addr)) {
 146                 pr_err("%s: attempt to assign an invalid ethernet address\n",
 147                        dev->name);
 148                 goto random;
 149         }
 150         if (!is_local_ether_addr(addr))
 151                 pr_warn("%s: assigning a globally valid ethernet address\n",
 152                         dev->name);
 153         return;
 154
 155 random:
 156         pr_info("%s: choosing a random ethernet address\n",
 157                 dev->name);
 158         eth_hw_addr_random(dev);
 159 }
 160
 161 /* ======================= TUNTAP TRANSPORT INTERFACE ====================== */
 162
 163 static int tuntap_open(struct iss_net_private *lp)
 164 {
 165         struct ifreq ifr;
 166         char *dev_name = lp->tp.info.tuntap.dev_name;
 167         int err = -EINVAL;
 168         int fd;
 169
 170         fd = simc_open("/dev/net/tun", 02, 0); /* O_RDWR */
 171         if (fd < 0) {
 172                 pr_err("%s: failed to open /dev/net/tun, returned %d (errno = %d)\n",
 173                        lp->dev->name, fd, errno);
 174                 return fd;
 175         }
 176
 177         memset(&ifr, 0, sizeof(ifr));
 178         ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
 179         strlcpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
 180
 181         err = simc_ioctl(fd, TUNSETIFF, &ifr);
 182         if (err < 0) {
 183                 pr_err("%s: failed to set interface %s, returned %d (errno = %d)\n",
 184                        lp->dev->name, dev_name, err, errno);
 185                 simc_close(fd);
 186                 return err;
 187         }
 188
 189         lp->tp.info.tuntap.fd = fd;
 190         return err;
 191 }
 192
 193 static void tuntap_close(struct iss_net_private *lp)
 194 {
 195         simc_close(lp->tp.info.tuntap.fd);
 196         lp->tp.info.tuntap.fd = -1;
 197 }
 198
 199 static int tuntap_read(struct iss_net_private *lp, struct sk_buff **skb)
 200 {
 201         return simc_read(lp->tp.info.tuntap.fd,
 202                         (*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
 203 }
 204
 205 static int tuntap_write(struct iss_net_private *lp, struct sk_buff **skb)
 206 {
 207         return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
 208 }
 209
 210 unsigned short tuntap_protocol(struct sk_buff *skb)
 211 {
 212         return eth_type_trans(skb, skb->dev);
 213 }
 214
 215 static int tuntap_poll(struct iss_net_private *lp)
 216 {
 217         return simc_poll(lp->tp.info.tuntap.fd);
 218 }
 219
 220 /*
 221  * ethX=tuntap,[mac address],device name
 222  */
 223
 224 static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
 225 {
 226         struct net_device *dev = lp->dev;
 227         char *dev_name = NULL, *mac_str = NULL, *rem = NULL;
 228
 229         /* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */
 230
 231         if (strncmp(init, TRANSPORT_TUNTAP_NAME,
 232                     sizeof(TRANSPORT_TUNTAP_NAME) - 1))
 233                 return 0;
 234
 235         init += sizeof(TRANSPORT_TUNTAP_NAME) - 1;
 236         if (*init == ',') {
 237                 rem = split_if_spec(init + 1, &mac_str, &dev_name);
 238                 if (rem != NULL) {
 239                         pr_err("%s: extra garbage on specification : '%s'\n",
 240                                dev->name, rem);
 241                         return 0;
 242                 }
 243         } else if (*init != '\0') {
 244                 pr_err("%s: invalid argument: %s. Skipping device!\n",
 245                        dev->name, init);
 246                 return 0;
 247         }
 248
 249         if (!dev_name) {
 250                 pr_err("%s: missing tuntap device name\n", dev->name);
 251                 return 0;
 252         }
 253
 254         strlcpy(lp->tp.info.tuntap.dev_name, dev_name,
 255                 sizeof(lp->tp.info.tuntap.dev_name));
 256
 257         setup_etheraddr(dev, mac_str);
 258
 259         lp->mtu = TRANSPORT_TUNTAP_MTU;
 260
 261         lp->tp.info.tuntap.fd = -1;
 262
 263         lp->tp.open = tuntap_open;
 264         lp->tp.close = tuntap_close;
 265         lp->tp.read = tuntap_read;
 266         lp->tp.write = tuntap_write;
 267         lp->tp.protocol = tuntap_protocol;
 268         lp->tp.poll = tuntap_poll;
 269
 270         return 1;
 271 }
 272
 273 /* ================================ ISS NET ================================ */
 274
 275 static int iss_net_rx(struct net_device *dev)
 276 {
 277         struct iss_net_private *lp = netdev_priv(dev);
 278         int pkt_len;
 279         struct sk_buff *skb;
 280
 281         /* Check if there is any new data. */
 282
 283         if (lp->tp.poll(lp) == 0)
 284                 return 0;
 285
 286         /* Try to allocate memory, if it fails, try again next round. */
 287
 288         skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER);
 289         if (skb == NULL) {
 290                 lp->stats.rx_dropped++;
 291                 return 0;
 292         }
 293
 294         skb_reserve(skb, 2);
 295
 296         /* Setup skb */
 297
 298         skb->dev = dev;
 299         skb_reset_mac_header(skb);
 300         pkt_len = lp->tp.read(lp, &skb);
 301         skb_put(skb, pkt_len);
 302
 303         if (pkt_len > 0) {
 304                 skb_trim(skb, pkt_len);
 305                 skb->protocol = lp->tp.protocol(skb);
 306
 307                 lp->stats.rx_bytes += skb->len;
 308                 lp->stats.rx_packets++;
 309                 netif_rx_ni(skb);
 310                 return pkt_len;
 311         }
 312         kfree_skb(skb);
 313         return pkt_len;
 314 }
 315
 316 static int iss_net_poll(void)
 317 {
 318         struct list_head *ele;
 319         int err, ret = 0;
 320
 321         spin_lock(&opened_lock);
 322
 323         list_for_each(ele, &opened) {
 324                 struct iss_net_private *lp;
 325
 326                 lp = list_entry(ele, struct iss_net_private, opened_list);
 327
 328                 if (!netif_running(lp->dev))
 329                         break;
 330
 331                 spin_lock(&lp->lock);
 332
 333                 while ((err = iss_net_rx(lp->dev)) > 0)
 334                         ret++;
 335
 336                 spin_unlock(&lp->lock);
 337
 338                 if (err < 0) {
 339                         pr_err("Device '%s' read returned %d, shutting it down\n",
 340                                lp->dev->name, err);
 341                         dev_close(lp->dev);
 342                 } else {
 343                         /* FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ); */
 344                 }
 345         }
 346
 347         spin_unlock(&opened_lock);
 348         return ret;
 349 }
 350
 351
 352 static void iss_net_timer(unsigned long priv)
 353 {
 354         struct iss_net_private *lp = (struct iss_net_private *)priv;
 355
 356         iss_net_poll();
 357         spin_lock(&lp->lock);
 358         mod_timer(&lp->timer, jiffies + lp->timer_val);
 359         spin_unlock(&lp->lock);
 360 }
 361
 362
 363 static int iss_net_open(struct net_device *dev)
 364 {
 365         struct iss_net_private *lp = netdev_priv(dev);
 366         int err;
 367
 368         spin_lock_bh(&lp->lock);
 369
 370         err = lp->tp.open(lp);
 371         if (err < 0)
 372                 goto out;
 373
 374         netif_start_queue(dev);
 375
 376         /* clear buffer - it can happen that the host side of the interface
 377          * is full when we get here. In this case, new data is never queued,
 378          * SIGIOs never arrive, and the net never works.
 379          */
 380         while ((err = iss_net_rx(dev)) > 0)
 381                 ;
 382
 383         spin_unlock_bh(&lp->lock);
 384         spin_lock_bh(&opened_lock);
 385         list_add(&lp->opened_list, &opened);
 386         spin_unlock_bh(&opened_lock);
 387         spin_lock_bh(&lp->lock);
 388
 389         init_timer(&lp->timer);
 390         lp->timer_val = ISS_NET_TIMER_VALUE;
 391         lp->timer.data = (unsigned long) lp;
 392         lp->timer.function = iss_net_timer;
 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(unsigned long _conn)
 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         init_timer(&lp->tl);
 586         lp->tl.function = iss_net_user_timer_expire;
 587
 588         return 0;
 589
 590 errout:
 591         /* FIXME: unregister; free, etc.. */
 592         return -EIO;
 593 }
 594
 595 /* ------------------------------------------------------------------------- */
 596
 597 /* Filled in during early boot */
 598
 599 struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
 600
 601 struct iss_net_init {
 602         struct list_head list;
 603         char *init;             /* init string */
 604         int index;
 605 };
 606
 607 /*
 608  * Parse the command line and look for 'ethX=...' fields, and register all
 609  * those fields. They will be later initialized in iss_net_init.
 610  */
 611
 612 #define ERR KERN_ERR "iss_net_setup: "
 613
 614 static int __init iss_net_setup(char *str)
 615 {
 616         struct iss_net_private *device = NULL;
 617         struct iss_net_init *new;
 618         struct list_head *ele;
 619         char *end;
 620         int rc;
 621         unsigned n;
 622
 623         end = strchr(str, '=');
 624         if (!end) {
 625                 printk(ERR "Expected '=' after device number\n");
 626                 return 1;
 627         }
 628         *end = 0;
 629         rc = kstrtouint(str, 0, &n);
 630         *end = '=';
 631         if (rc < 0) {
 632                 printk(ERR "Failed to parse '%s'\n", str);
 633                 return 1;
 634         }
 635         str = end;
 636
 637         spin_lock(&devices_lock);
 638
 639         list_for_each(ele, &devices) {
 640                 device = list_entry(ele, struct iss_net_private, device_list);
 641                 if (device->index == n)
 642                         break;
 643         }
 644
 645         spin_unlock(&devices_lock);
 646
 647         if (device && device->index == n) {
 648                 printk(ERR "Device %u already configured\n", n);
 649                 return 1;
 650         }
 651
 652         new = alloc_bootmem(sizeof(*new));
 653         if (new == NULL) {
 654                 printk(ERR "Alloc_bootmem failed\n");
 655                 return 1;
 656         }
 657
 658         INIT_LIST_HEAD(&new->list);
 659         new->index = n;
 660         new->init = str + 1;
 661
 662         list_add_tail(&new->list, &eth_cmd_line);
 663         return 1;
 664 }
 665
 666 #undef ERR
 667
 668 __setup("eth", iss_net_setup);
 669
 670 /*
 671  * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
 672  */
 673
 674 static int iss_net_init(void)
 675 {
 676         struct list_head *ele, *next;
 677
 678         /* Walk through all Ethernet devices specified in the command line. */
 679
 680         list_for_each_safe(ele, next, &eth_cmd_line) {
 681                 struct iss_net_init *eth;
 682                 eth = list_entry(ele, struct iss_net_init, list);
 683                 iss_net_configure(eth->index, eth->init);
 684         }
 685
 686         return 1;
 687 }
 688 device_initcall(iss_net_init);