drivers/staging/most/aim-network/networking.c

   1 /*
   2  * Networking AIM - Networking Application Interface Module for MostCore
   3  *
   4  * Copyright (C) 2015, Microchip Technology Germany II GmbH & Co. KG
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * This file is licensed under GPLv2.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/slab.h>
  20 #include <linux/init.h>
  21 #include <linux/list.h>
  22 #include <linux/wait.h>
  23 #include <linux/kobject.h>
  24 #include "mostcore.h"
  25 #include "networking.h"
  26
  27
  28 #define MEP_HDR_LEN 8
  29 #define MDP_HDR_LEN 16
  30 #define MAMAC_DATA_LEN (1024 - MDP_HDR_LEN)
  31
  32 #define PMHL 5
  33
  34 #define PMS_TELID_UNSEGM_MAMAC  0x0A
  35 #define PMS_FIFONO_MDP          0x01
  36 #define PMS_FIFONO_MEP          0x04
  37 #define PMS_MSGTYPE_DATA        0x04
  38 #define PMS_DEF_PRIO            0
  39 #define MEP_DEF_RETRY           15
  40
  41 #define PMS_FIFONO_MASK         0x07
  42 #define PMS_FIFONO_SHIFT        3
  43 #define PMS_RETRY_SHIFT         4
  44 #define PMS_TELID_MASK          0x0F
  45 #define PMS_TELID_SHIFT         4
  46
  47 #define HB(value)               ((u8)((u16)(value) >> 8))
  48 #define LB(value)               ((u8)(value))
  49
  50
  51
  52 #define EXTRACT_BIT_SET(bitset_name, value) \
  53         (((value) >> bitset_name##_SHIFT) & bitset_name##_MASK)
  54
  55 #define PMS_IS_MEP(buf, len) \
  56         ((len) > MEP_HDR_LEN && \
  57          EXTRACT_BIT_SET(PMS_FIFONO, (buf)[3]) == PMS_FIFONO_MEP)
  58
  59 #define PMS_IS_MAMAC(buf, len) \
  60         ((len) > MDP_HDR_LEN && \
  61          EXTRACT_BIT_SET(PMS_FIFONO, (buf)[3]) == PMS_FIFONO_MDP && \
  62          EXTRACT_BIT_SET(PMS_TELID, (buf)[14]) == PMS_TELID_UNSEGM_MAMAC)
  63
  64 struct net_dev_channel {
  65         bool linked;
  66         int ch_id;
  67 };
  68
  69 struct net_dev_context {
  70         struct most_interface *iface;
  71         bool channels_opened;
  72         bool is_mamac;
  73         unsigned char link_stat;
  74         struct net_device *dev;
  75         struct net_dev_channel rx;
  76         struct net_dev_channel tx;
  77         struct list_head list;
  78 };
  79
  80 static struct list_head net_devices = LIST_HEAD_INIT(net_devices);
  81 static struct spinlock list_lock;
  82 static struct most_aim aim;
  83
  84
  85 static int skb_to_mamac(const struct sk_buff *skb, struct mbo *mbo)
  86 {
  87         u8 *buff = mbo->virt_address;
  88         const u8 broadcast[] = { 0x03, 0xFF };
  89         const u8 *dest_addr = skb->data + 4;
  90         const u8 *eth_type = skb->data + 12;
  91         unsigned int payload_len = skb->len - ETH_HLEN;
  92         unsigned int mdp_len = payload_len + MDP_HDR_LEN;
  93
  94         if (mbo->buffer_length < mdp_len) {
  95                 pr_err("drop: too small buffer! (%d for %d)\n",
  96                        mbo->buffer_length, mdp_len);
  97                 return -EINVAL;
  98         }
  99
 100         if (skb->len < ETH_HLEN) {
 101                 pr_err("drop: too small packet! (%d)\n", skb->len);
 102                 return -EINVAL;
 103         }
 104
 105         if (dest_addr[0] == 0xFF && dest_addr[1] == 0xFF)
 106                 dest_addr = broadcast;
 107
 108         *buff++ = HB(mdp_len - 2);
 109         *buff++ = LB(mdp_len - 2);
 110
 111         *buff++ = PMHL;
 112         *buff++ = (PMS_FIFONO_MDP << PMS_FIFONO_SHIFT) | PMS_MSGTYPE_DATA;
 113         *buff++ = PMS_DEF_PRIO;
 114         *buff++ = dest_addr[0];
 115         *buff++ = dest_addr[1];
 116         *buff++ = 0x00;
 117
 118         *buff++ = HB(payload_len + 6);
 119         *buff++ = LB(payload_len + 6);
 120
 121         /* end of FPH here */
 122
 123         *buff++ = eth_type[0];
 124         *buff++ = eth_type[1];
 125         *buff++ = 0;
 126         *buff++ = 0;
 127
 128         *buff++ = PMS_TELID_UNSEGM_MAMAC << 4 | HB(payload_len);
 129         *buff++ = LB(payload_len);
 130
 131         memcpy(buff, skb->data + ETH_HLEN, payload_len);
 132         mbo->buffer_length = mdp_len;
 133         return 0;
 134 }
 135
 136 static int skb_to_mep(const struct sk_buff *skb, struct mbo *mbo)
 137 {
 138         u8 *buff = mbo->virt_address;
 139         unsigned int mep_len = skb->len + MEP_HDR_LEN;
 140
 141         if (mbo->buffer_length < mep_len) {
 142                 pr_err("drop: too small buffer! (%d for %d)\n",
 143                        mbo->buffer_length, mep_len);
 144                 return -EINVAL;
 145         }
 146
 147         *buff++ = HB(mep_len - 2);
 148         *buff++ = LB(mep_len - 2);
 149
 150         *buff++ = PMHL;
 151         *buff++ = (PMS_FIFONO_MEP << PMS_FIFONO_SHIFT) | PMS_MSGTYPE_DATA;
 152         *buff++ = (MEP_DEF_RETRY << PMS_RETRY_SHIFT) | PMS_DEF_PRIO;
 153         *buff++ = 0;
 154         *buff++ = 0;
 155         *buff++ = 0;
 156
 157         memcpy(buff, skb->data, skb->len);
 158         mbo->buffer_length = mep_len;
 159         return 0;
 160 }
 161
 162 static int most_nd_set_mac_address(struct net_device *dev, void *p)
 163 {
 164         struct net_dev_context *nd = dev->ml_priv;
 165         int err = eth_mac_addr(dev, p);
 166
 167         if (err)
 168                 return err;
 169
 170         BUG_ON(nd->dev != dev);
 171
 172         nd->is_mamac =
 173                 (dev->dev_addr[0] == 0 && dev->dev_addr[1] == 0 &&
 174                  dev->dev_addr[2] == 0 && dev->dev_addr[3] == 0);
 175
 176         /*
 177          * Set default MTU for the given packet type.
 178          * It is still possible to change MTU using ip tools afterwards.
 179          */
 180         dev->mtu = nd->is_mamac ? MAMAC_DATA_LEN : ETH_DATA_LEN;
 181
 182         return 0;
 183 }
 184
 185 static int most_nd_open(struct net_device *dev)
 186 {
 187         struct net_dev_context *nd = dev->ml_priv;
 188
 189         pr_info("open net device %s\n", dev->name);
 190
 191         BUG_ON(nd->dev != dev);
 192
 193         if (nd->channels_opened)
 194                 return -EFAULT;
 195
 196         BUG_ON(!nd->tx.linked || !nd->rx.linked);
 197
 198         if (most_start_channel(nd->iface, nd->rx.ch_id)) {
 199                 pr_err("most_start_channel() failed\n");
 200                 return -EBUSY;
 201         }
 202
 203         if (most_start_channel(nd->iface, nd->tx.ch_id)) {
 204                 pr_err("most_start_channel() failed\n");
 205                 most_stop_channel(nd->iface, nd->rx.ch_id);
 206                 return -EBUSY;
 207         }
 208
 209         nd->channels_opened = true;
 210
 211         if (nd->is_mamac) {
 212                 nd->link_stat = 1;
 213                 netif_wake_queue(dev);
 214         } else {
 215                 nd->iface->request_netinfo(nd->iface, nd->tx.ch_id);
 216         }
 217
 218         return 0;
 219 }
 220
 221 static int most_nd_stop(struct net_device *dev)
 222 {
 223         struct net_dev_context *nd = dev->ml_priv;
 224
 225         pr_info("stop net device %s\n", dev->name);
 226
 227         BUG_ON(nd->dev != dev);
 228         netif_stop_queue(dev);
 229
 230         if (nd->channels_opened) {
 231                 most_stop_channel(nd->iface, nd->rx.ch_id);
 232                 most_stop_channel(nd->iface, nd->tx.ch_id);
 233                 nd->channels_opened = false;
 234         }
 235
 236         return 0;
 237 }
 238
 239 static netdev_tx_t most_nd_start_xmit(struct sk_buff *skb,
 240                                       struct net_device *dev)
 241 {
 242         struct net_dev_context *nd = dev->ml_priv;
 243         struct mbo *mbo;
 244         int ret;
 245
 246         BUG_ON(nd->dev != dev);
 247
 248         mbo = most_get_mbo(nd->iface, nd->tx.ch_id);
 249
 250         if (!mbo) {
 251                 netif_stop_queue(dev);
 252                 dev->stats.tx_fifo_errors++;
 253                 return NETDEV_TX_BUSY;
 254         }
 255
 256         if (nd->is_mamac)
 257                 ret = skb_to_mamac(skb, mbo);
 258         else
 259                 ret = skb_to_mep(skb, mbo);
 260
 261         if (ret) {
 262                 most_put_mbo(mbo);
 263                 dev->stats.tx_dropped++;
 264                 kfree_skb(skb);
 265                 return NETDEV_TX_OK;
 266         }
 267
 268         most_submit_mbo(mbo);
 269         dev->stats.tx_packets++;
 270         dev->stats.tx_bytes += skb->len;
 271         kfree_skb(skb);
 272         return NETDEV_TX_OK;
 273 }
 274
 275 static const struct net_device_ops most_nd_ops = {
 276         .ndo_open = most_nd_open,
 277         .ndo_stop = most_nd_stop,
 278         .ndo_start_xmit = most_nd_start_xmit,
 279         .ndo_set_mac_address = most_nd_set_mac_address,
 280 };
 281
 282 static void most_nd_setup(struct net_device *dev)
 283 {
 284         pr_info("setup net device %s\n", dev->name);
 285         ether_setup(dev);
 286         dev->netdev_ops = &most_nd_ops;
 287 }
 288
 289 static void most_net_rm_netdev_safe(struct net_dev_context *nd)
 290 {
 291         if (!nd->dev)
 292                 return;
 293
 294         pr_info("remove net device %p\n", nd->dev);
 295
 296         unregister_netdev(nd->dev);
 297         free_netdev(nd->dev);
 298         nd->dev = 0;
 299 }
 300
 301 static struct net_dev_context *get_net_dev_context(
 302         struct most_interface *iface)
 303 {
 304         struct net_dev_context *nd, *tmp;
 305
 306         spin_lock(&list_lock);
 307         list_for_each_entry_safe(nd, tmp, &net_devices, list) {
 308                 if (nd->iface == iface) {
 309                         spin_unlock(&list_lock);
 310                         return nd;
 311                 }
 312         }
 313         spin_unlock(&list_lock);
 314         return NULL;
 315 }
 316
 317 static int aim_probe_channel(struct most_interface *iface, int channel_idx,
 318                              struct most_channel_config *ccfg,
 319                              struct kobject *parent, char *name)
 320 {
 321         struct net_dev_context *nd;
 322         struct net_dev_channel *ch;
 323
 324         if (!iface)
 325                 return -EINVAL;
 326
 327         if (ccfg->data_type != MOST_CH_ASYNC)
 328                 return -EINVAL;
 329
 330         nd = get_net_dev_context(iface);
 331
 332         if (!nd) {
 333                 nd = kzalloc(sizeof(*nd), GFP_KERNEL);
 334                 if (!nd)
 335                         return -ENOMEM;
 336
 337                 nd->iface = iface;
 338
 339                 spin_lock(&list_lock);
 340                 list_add(&nd->list, &net_devices);
 341                 spin_unlock(&list_lock);
 342         }
 343
 344         ch = ccfg->direction == MOST_CH_TX ? &nd->tx : &nd->rx;
 345         if (ch->linked) {
 346                 pr_err("only one channel per instance & direction allowed\n");
 347                 return -EINVAL;
 348         }
 349
 350         if (nd->tx.linked || nd->rx.linked) {
 351                 struct net_device *dev =
 352                         alloc_netdev(0, "meth%d", NET_NAME_UNKNOWN, most_nd_setup);
 353
 354                 if (!dev) {
 355                         pr_err("no memory for net_device\n");
 356                         return -ENOMEM;
 357                 }
 358
 359                 nd->dev = dev;
 360
 361                 dev->ml_priv = nd;
 362                 if (register_netdev(dev)) {
 363                         pr_err("registering net device failed\n");
 364                         free_netdev(dev);
 365                         return -EINVAL;
 366                 }
 367         }
 368
 369         ch->ch_id = channel_idx;
 370         ch->linked = true;
 371
 372         return 0;
 373 }
 374
 375 static int aim_disconnect_channel(struct most_interface *iface,
 376                                   int channel_idx)
 377 {
 378         struct net_dev_context *nd;
 379         struct net_dev_channel *ch;
 380
 381         nd = get_net_dev_context(iface);
 382         if (!nd)
 383                 return -EINVAL;
 384
 385         if (nd->rx.linked && channel_idx == nd->rx.ch_id)
 386                 ch = &nd->rx;
 387         else if (nd->tx.linked && channel_idx == nd->tx.ch_id)
 388                 ch = &nd->tx;
 389         else
 390                 return -EINVAL;
 391
 392         ch->linked = false;
 393
 394         /*
 395          * do not call most_stop_channel() here, because channels are
 396          * going to be closed in ndo_stop() after unregister_netdev()
 397          */
 398         most_net_rm_netdev_safe(nd);
 399
 400         if (!nd->rx.linked && !nd->tx.linked) {
 401                 spin_lock(&list_lock);
 402                 list_del(&nd->list);
 403                 spin_unlock(&list_lock);
 404                 kfree(nd);
 405         }
 406
 407         return 0;
 408 }
 409
 410 static int aim_resume_tx_channel(struct most_interface *iface,
 411                                  int channel_idx)
 412 {
 413         struct net_dev_context *nd;
 414
 415         nd = get_net_dev_context(iface);
 416         if (!nd || !nd->channels_opened || nd->tx.ch_id != channel_idx)
 417                 return 0;
 418
 419         if (!nd->dev)
 420                 return 0;
 421
 422         netif_wake_queue(nd->dev);
 423         return 0;
 424 }
 425
 426 static int aim_rx_data(struct mbo *mbo)
 427 {
 428         const u32 zero = 0;
 429         struct net_dev_context *nd;
 430         char *buf = mbo->virt_address;
 431         uint32_t len = mbo->processed_length;
 432         struct sk_buff *skb;
 433         struct net_device *dev;
 434
 435         nd = get_net_dev_context(mbo->ifp);
 436         if (!nd || !nd->channels_opened || nd->rx.ch_id != mbo->hdm_channel_id)
 437                 return -EIO;
 438
 439         dev = nd->dev;
 440         if (!dev) {
 441                 pr_err_once("drop packet: missing net_device\n");
 442                 return -EIO;
 443         }
 444
 445         if (nd->is_mamac) {
 446                 if (!PMS_IS_MAMAC(buf, len))
 447                         return -EIO;
 448
 449                 skb = dev_alloc_skb(len - MDP_HDR_LEN + 2 * ETH_ALEN + 2);
 450         } else {
 451                 if (!PMS_IS_MEP(buf, len))
 452                         return -EIO;
 453
 454                 skb = dev_alloc_skb(len - MEP_HDR_LEN);
 455         }
 456
 457         if (!skb) {
 458                 dev->stats.rx_dropped++;
 459                 pr_err_once("drop packet: no memory for skb\n");
 460                 goto out;
 461         }
 462
 463         skb->dev = dev;
 464
 465         if (nd->is_mamac) {
 466                 /* dest */
 467                 memcpy(skb_put(skb, ETH_ALEN), dev->dev_addr, ETH_ALEN);
 468
 469                 /* src */
 470                 memcpy(skb_put(skb, 4), &zero, 4);
 471                 memcpy(skb_put(skb, 2), buf + 5, 2);
 472
 473                 /* eth type */
 474                 memcpy(skb_put(skb, 2), buf + 10, 2);
 475
 476                 buf += MDP_HDR_LEN;
 477                 len -= MDP_HDR_LEN;
 478         } else {
 479                 buf += MEP_HDR_LEN;
 480                 len -= MEP_HDR_LEN;
 481         }
 482
 483         memcpy(skb_put(skb, len), buf, len);
 484         skb->protocol = eth_type_trans(skb, dev);
 485         dev->stats.rx_packets++;
 486         dev->stats.rx_bytes += skb->len;
 487         netif_rx(skb);
 488
 489 out:
 490         most_put_mbo(mbo);
 491         return 0;
 492 }
 493
 494 static int __init most_net_init(void)
 495 {
 496         pr_info("most_net_init()\n");
 497         spin_lock_init(&list_lock);
 498         aim.name = "networking";
 499         aim.probe_channel = aim_probe_channel;
 500         aim.disconnect_channel = aim_disconnect_channel;
 501         aim.tx_completion = aim_resume_tx_channel;
 502         aim.rx_completion = aim_rx_data;
 503         return most_register_aim(&aim);
 504 }
 505
 506 static void __exit most_net_exit(void)
 507 {
 508         struct net_dev_context *nd, *tmp;
 509
 510         spin_lock(&list_lock);
 511         list_for_each_entry_safe(nd, tmp, &net_devices, list) {
 512                 list_del(&nd->list);
 513                 spin_unlock(&list_lock);
 514                 /*
 515                  * do not call most_stop_channel() here, because channels are
 516                  * going to be closed in ndo_stop() after unregister_netdev()
 517                  */
 518                 most_net_rm_netdev_safe(nd);
 519                 kfree(nd);
 520                 spin_lock(&list_lock);
 521         }
 522         spin_unlock(&list_lock);
 523
 524         most_deregister_aim(&aim);
 525         pr_info("most_net_exit()\n");
 526 }
 527
 528 /**
 529  * most_deliver_netinfo - callback for HDM to be informed about HW's MAC
 530  * @param iface - most interface instance
 531  * @param link_stat - link status
 532  * @param mac_addr - MAC address
 533  */
 534 void most_deliver_netinfo(struct most_interface *iface,
 535                           unsigned char link_stat, unsigned char *mac_addr)
 536 {
 537         struct net_dev_context *nd;
 538         struct net_device *dev;
 539
 540         pr_info("Received netinfo from %s\n", iface->description);
 541
 542         nd = get_net_dev_context(iface);
 543         if (!nd)
 544                 return;
 545
 546         dev = nd->dev;
 547         if (!dev)
 548                 return;
 549
 550         if (mac_addr)
 551                 memcpy(dev->dev_addr, mac_addr, ETH_ALEN);
 552
 553         if (nd->link_stat != link_stat) {
 554                 nd->link_stat = link_stat;
 555                 if (nd->link_stat)
 556                         netif_wake_queue(dev);
 557                 else
 558                         netif_stop_queue(dev);
 559         }
 560 }
 561 EXPORT_SYMBOL(most_deliver_netinfo);
 562
 563 module_init(most_net_init);
 564 module_exit(most_net_exit);
 565 MODULE_LICENSE("GPL");
 566 MODULE_AUTHOR("Andrey Shvetsov <andrey.shvetsov@k2l.de>");
 567 MODULE_DESCRIPTION("Networking Application Interface Module for MostCore");