drivers/net/can/dev/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
   3  * Copyright (C) 2006 Andrey Volkov, Varma Electronics
   4  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/if_arp.h>
  12 #include <linux/workqueue.h>
  13 #include <linux/can.h>
  14 #include <linux/can/can-ml.h>
  15 #include <linux/can/dev.h>
  16 #include <linux/can/skb.h>
  17 #include <linux/can/netlink.h>
  18 #include <linux/can/led.h>
  19 #include <linux/of.h>
  20 #include <net/rtnetlink.h>
  21
  22 #define MOD_DESC "CAN device driver interface"
  23
  24 MODULE_DESCRIPTION(MOD_DESC);
  25 MODULE_LICENSE("GPL v2");
  26 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  27
  28 /* CAN DLC to real data length conversion helpers */
  29
  30 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
  31                              8, 12, 16, 20, 24, 32, 48, 64};
  32
  33 /* get data length from can_dlc with sanitized can_dlc */
  34 u8 can_dlc2len(u8 can_dlc)
  35 {
  36         return dlc2len[can_dlc & 0x0F];
  37 }
  38 EXPORT_SYMBOL_GPL(can_dlc2len);
  39
  40 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,         /* 0 - 8 */
  41                              9, 9, 9, 9,                        /* 9 - 12 */
  42                              10, 10, 10, 10,                    /* 13 - 16 */
  43                              11, 11, 11, 11,                    /* 17 - 20 */
  44                              12, 12, 12, 12,                    /* 21 - 24 */
  45                              13, 13, 13, 13, 13, 13, 13, 13,    /* 25 - 32 */
  46                              14, 14, 14, 14, 14, 14, 14, 14,    /* 33 - 40 */
  47                              14, 14, 14, 14, 14, 14, 14, 14,    /* 41 - 48 */
  48                              15, 15, 15, 15, 15, 15, 15, 15,    /* 49 - 56 */
  49                              15, 15, 15, 15, 15, 15, 15, 15};   /* 57 - 64 */
  50
  51 /* map the sanitized data length to an appropriate data length code */
  52 u8 can_len2dlc(u8 len)
  53 {
  54         if (unlikely(len > 64))
  55                 return 0xF;
  56
  57         return len2dlc[len];
  58 }
  59 EXPORT_SYMBOL_GPL(can_len2dlc);
  60
  61 #ifdef CONFIG_CAN_CALC_BITTIMING
  62 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
  63
  64 /* Bit-timing calculation derived from:
  65  *
  66  * Code based on LinCAN sources and H8S2638 project
  67  * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
  68  * Copyright 2005      Stanislav Marek
  69  * email: pisa@cmp.felk.cvut.cz
  70  *
  71  * Calculates proper bit-timing parameters for a specified bit-rate
  72  * and sample-point, which can then be used to set the bit-timing
  73  * registers of the CAN controller. You can find more information
  74  * in the header file linux/can/netlink.h.
  75  */
  76 static int
  77 can_update_sample_point(const struct can_bittiming_const *btc,
  78                         unsigned int sample_point_nominal, unsigned int tseg,
  79                         unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
  80                         unsigned int *sample_point_error_ptr)
  81 {
  82         unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
  83         unsigned int sample_point, best_sample_point = 0;
  84         unsigned int tseg1, tseg2;
  85         int i;
  86
  87         for (i = 0; i <= 1; i++) {
  88                 tseg2 = tseg + CAN_SYNC_SEG -
  89                         (sample_point_nominal * (tseg + CAN_SYNC_SEG)) /
  90                         1000 - i;
  91                 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
  92                 tseg1 = tseg - tseg2;
  93                 if (tseg1 > btc->tseg1_max) {
  94                         tseg1 = btc->tseg1_max;
  95                         tseg2 = tseg - tseg1;
  96                 }
  97
  98                 sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) /
  99                         (tseg + CAN_SYNC_SEG);
 100                 sample_point_error = abs(sample_point_nominal - sample_point);
 101
 102                 if (sample_point <= sample_point_nominal &&
 103                     sample_point_error < best_sample_point_error) {
 104                         best_sample_point = sample_point;
 105                         best_sample_point_error = sample_point_error;
 106                         *tseg1_ptr = tseg1;
 107                         *tseg2_ptr = tseg2;
 108                 }
 109         }
 110
 111         if (sample_point_error_ptr)
 112                 *sample_point_error_ptr = best_sample_point_error;
 113
 114         return best_sample_point;
 115 }
 116
 117 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 118                               const struct can_bittiming_const *btc)
 119 {
 120         struct can_priv *priv = netdev_priv(dev);
 121         unsigned int bitrate;                   /* current bitrate */
 122         unsigned int bitrate_error;             /* difference between current and nominal value */
 123         unsigned int best_bitrate_error = UINT_MAX;
 124         unsigned int sample_point_error;        /* difference between current and nominal value */
 125         unsigned int best_sample_point_error = UINT_MAX;
 126         unsigned int sample_point_nominal;      /* nominal sample point */
 127         unsigned int best_tseg = 0;             /* current best value for tseg */
 128         unsigned int best_brp = 0;              /* current best value for brp */
 129         unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
 130         u64 v64;
 131
 132         /* Use CiA recommended sample points */
 133         if (bt->sample_point) {
 134                 sample_point_nominal = bt->sample_point;
 135         } else {
 136                 if (bt->bitrate > 800000)
 137                         sample_point_nominal = 750;
 138                 else if (bt->bitrate > 500000)
 139                         sample_point_nominal = 800;
 140                 else
 141                         sample_point_nominal = 875;
 142         }
 143
 144         /* tseg even = round down, odd = round up */
 145         for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
 146              tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
 147                 tsegall = CAN_SYNC_SEG + tseg / 2;
 148
 149                 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
 150                 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
 151
 152                 /* choose brp step which is possible in system */
 153                 brp = (brp / btc->brp_inc) * btc->brp_inc;
 154                 if (brp < btc->brp_min || brp > btc->brp_max)
 155                         continue;
 156
 157                 bitrate = priv->clock.freq / (brp * tsegall);
 158                 bitrate_error = abs(bt->bitrate - bitrate);
 159
 160                 /* tseg brp biterror */
 161                 if (bitrate_error > best_bitrate_error)
 162                         continue;
 163
 164                 /* reset sample point error if we have a better bitrate */
 165                 if (bitrate_error < best_bitrate_error)
 166                         best_sample_point_error = UINT_MAX;
 167
 168                 can_update_sample_point(btc, sample_point_nominal, tseg / 2,
 169                                         &tseg1, &tseg2, &sample_point_error);
 170                 if (sample_point_error > best_sample_point_error)
 171                         continue;
 172
 173                 best_sample_point_error = sample_point_error;
 174                 best_bitrate_error = bitrate_error;
 175                 best_tseg = tseg / 2;
 176                 best_brp = brp;
 177
 178                 if (bitrate_error == 0 && sample_point_error == 0)
 179                         break;
 180         }
 181
 182         if (best_bitrate_error) {
 183                 /* Error in one-tenth of a percent */
 184                 v64 = (u64)best_bitrate_error * 1000;
 185                 do_div(v64, bt->bitrate);
 186                 bitrate_error = (u32)v64;
 187                 if (bitrate_error > CAN_CALC_MAX_ERROR) {
 188                         netdev_err(dev,
 189                                    "bitrate error %d.%d%% too high\n",
 190                                    bitrate_error / 10, bitrate_error % 10);
 191                         return -EDOM;
 192                 }
 193                 netdev_warn(dev, "bitrate error %d.%d%%\n",
 194                             bitrate_error / 10, bitrate_error % 10);
 195         }
 196
 197         /* real sample point */
 198         bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
 199                                                    best_tseg, &tseg1, &tseg2,
 200                                                    NULL);
 201
 202         v64 = (u64)best_brp * 1000 * 1000 * 1000;
 203         do_div(v64, priv->clock.freq);
 204         bt->tq = (u32)v64;
 205         bt->prop_seg = tseg1 / 2;
 206         bt->phase_seg1 = tseg1 - bt->prop_seg;
 207         bt->phase_seg2 = tseg2;
 208
 209         /* check for sjw user settings */
 210         if (!bt->sjw || !btc->sjw_max) {
 211                 bt->sjw = 1;
 212         } else {
 213                 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
 214                 if (bt->sjw > btc->sjw_max)
 215                         bt->sjw = btc->sjw_max;
 216                 /* bt->sjw must not be higher than tseg2 */
 217                 if (tseg2 < bt->sjw)
 218                         bt->sjw = tseg2;
 219         }
 220
 221         bt->brp = best_brp;
 222
 223         /* real bitrate */
 224         bt->bitrate = priv->clock.freq /
 225                 (bt->brp * (CAN_SYNC_SEG + tseg1 + tseg2));
 226
 227         return 0;
 228 }
 229 #else /* !CONFIG_CAN_CALC_BITTIMING */
 230 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 231                               const struct can_bittiming_const *btc)
 232 {
 233         netdev_err(dev, "bit-timing calculation not available\n");
 234         return -EINVAL;
 235 }
 236 #endif /* CONFIG_CAN_CALC_BITTIMING */
 237
 238 /* Checks the validity of the specified bit-timing parameters prop_seg,
 239  * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
 240  * prescaler value brp. You can find more information in the header
 241  * file linux/can/netlink.h.
 242  */
 243 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
 244                                const struct can_bittiming_const *btc)
 245 {
 246         struct can_priv *priv = netdev_priv(dev);
 247         int tseg1, alltseg;
 248         u64 brp64;
 249
 250         tseg1 = bt->prop_seg + bt->phase_seg1;
 251         if (!bt->sjw)
 252                 bt->sjw = 1;
 253         if (bt->sjw > btc->sjw_max ||
 254             tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
 255             bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
 256                 return -ERANGE;
 257
 258         brp64 = (u64)priv->clock.freq * (u64)bt->tq;
 259         if (btc->brp_inc > 1)
 260                 do_div(brp64, btc->brp_inc);
 261         brp64 += 500000000UL - 1;
 262         do_div(brp64, 1000000000UL); /* the practicable BRP */
 263         if (btc->brp_inc > 1)
 264                 brp64 *= btc->brp_inc;
 265         bt->brp = (u32)brp64;
 266
 267         if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
 268                 return -EINVAL;
 269
 270         alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
 271         bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
 272         bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
 273
 274         return 0;
 275 }
 276
 277 /* Checks the validity of predefined bitrate settings */
 278 static int
 279 can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
 280                      const u32 *bitrate_const,
 281                      const unsigned int bitrate_const_cnt)
 282 {
 283         struct can_priv *priv = netdev_priv(dev);
 284         unsigned int i;
 285
 286         for (i = 0; i < bitrate_const_cnt; i++) {
 287                 if (bt->bitrate == bitrate_const[i])
 288                         break;
 289         }
 290
 291         if (i >= priv->bitrate_const_cnt)
 292                 return -EINVAL;
 293
 294         return 0;
 295 }
 296
 297 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
 298                              const struct can_bittiming_const *btc,
 299                              const u32 *bitrate_const,
 300                              const unsigned int bitrate_const_cnt)
 301 {
 302         int err;
 303
 304         /* Depending on the given can_bittiming parameter structure the CAN
 305          * timing parameters are calculated based on the provided bitrate OR
 306          * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 307          * provided directly which are then checked and fixed up.
 308          */
 309         if (!bt->tq && bt->bitrate && btc)
 310                 err = can_calc_bittiming(dev, bt, btc);
 311         else if (bt->tq && !bt->bitrate && btc)
 312                 err = can_fixup_bittiming(dev, bt, btc);
 313         else if (!bt->tq && bt->bitrate && bitrate_const)
 314                 err = can_validate_bitrate(dev, bt, bitrate_const,
 315                                            bitrate_const_cnt);
 316         else
 317                 err = -EINVAL;
 318
 319         return err;
 320 }
 321
 322 static void can_update_state_error_stats(struct net_device *dev,
 323                                          enum can_state new_state)
 324 {
 325         struct can_priv *priv = netdev_priv(dev);
 326
 327         if (new_state <= priv->state)
 328                 return;
 329
 330         switch (new_state) {
 331         case CAN_STATE_ERROR_WARNING:
 332                 priv->can_stats.error_warning++;
 333                 break;
 334         case CAN_STATE_ERROR_PASSIVE:
 335                 priv->can_stats.error_passive++;
 336                 break;
 337         case CAN_STATE_BUS_OFF:
 338                 priv->can_stats.bus_off++;
 339                 break;
 340         default:
 341                 break;
 342         }
 343 }
 344
 345 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
 346 {
 347         switch (state) {
 348         case CAN_STATE_ERROR_ACTIVE:
 349                 return CAN_ERR_CRTL_ACTIVE;
 350         case CAN_STATE_ERROR_WARNING:
 351                 return CAN_ERR_CRTL_TX_WARNING;
 352         case CAN_STATE_ERROR_PASSIVE:
 353                 return CAN_ERR_CRTL_TX_PASSIVE;
 354         default:
 355                 return 0;
 356         }
 357 }
 358
 359 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
 360 {
 361         switch (state) {
 362         case CAN_STATE_ERROR_ACTIVE:
 363                 return CAN_ERR_CRTL_ACTIVE;
 364         case CAN_STATE_ERROR_WARNING:
 365                 return CAN_ERR_CRTL_RX_WARNING;
 366         case CAN_STATE_ERROR_PASSIVE:
 367                 return CAN_ERR_CRTL_RX_PASSIVE;
 368         default:
 369                 return 0;
 370         }
 371 }
 372
 373 static const char *can_get_state_str(const enum can_state state)
 374 {
 375         switch (state) {
 376         case CAN_STATE_ERROR_ACTIVE:
 377                 return "Error Active";
 378         case CAN_STATE_ERROR_WARNING:
 379                 return "Error Warning";
 380         case CAN_STATE_ERROR_PASSIVE:
 381                 return "Error Passive";
 382         case CAN_STATE_BUS_OFF:
 383                 return "Bus Off";
 384         case CAN_STATE_STOPPED:
 385                 return "Stopped";
 386         case CAN_STATE_SLEEPING:
 387                 return "Sleeping";
 388         default:
 389                 return "<unknown>";
 390         }
 391
 392         return "<unknown>";
 393 }
 394
 395 void can_change_state(struct net_device *dev, struct can_frame *cf,
 396                       enum can_state tx_state, enum can_state rx_state)
 397 {
 398         struct can_priv *priv = netdev_priv(dev);
 399         enum can_state new_state = max(tx_state, rx_state);
 400
 401         if (unlikely(new_state == priv->state)) {
 402                 netdev_warn(dev, "%s: oops, state did not change", __func__);
 403                 return;
 404         }
 405
 406         netdev_dbg(dev, "Controller changed from %s State (%d) into %s State (%d).\n",
 407                    can_get_state_str(priv->state), priv->state,
 408                    can_get_state_str(new_state), new_state);
 409
 410         can_update_state_error_stats(dev, new_state);
 411         priv->state = new_state;
 412
 413         if (!cf)
 414                 return;
 415
 416         if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
 417                 cf->can_id |= CAN_ERR_BUSOFF;
 418                 return;
 419         }
 420
 421         cf->can_id |= CAN_ERR_CRTL;
 422         cf->data[1] |= tx_state >= rx_state ?
 423                        can_tx_state_to_frame(dev, tx_state) : 0;
 424         cf->data[1] |= tx_state <= rx_state ?
 425                        can_rx_state_to_frame(dev, rx_state) : 0;
 426 }
 427 EXPORT_SYMBOL_GPL(can_change_state);
 428
 429 /* Local echo of CAN messages
 430  *
 431  * CAN network devices *should* support a local echo functionality
 432  * (see Documentation/networking/can.rst). To test the handling of CAN
 433  * interfaces that do not support the local echo both driver types are
 434  * implemented. In the case that the driver does not support the echo
 435  * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
 436  * to perform the echo as a fallback solution.
 437  */
 438 static void can_flush_echo_skb(struct net_device *dev)
 439 {
 440         struct can_priv *priv = netdev_priv(dev);
 441         struct net_device_stats *stats = &dev->stats;
 442         int i;
 443
 444         for (i = 0; i < priv->echo_skb_max; i++) {
 445                 if (priv->echo_skb[i]) {
 446                         kfree_skb(priv->echo_skb[i]);
 447                         priv->echo_skb[i] = NULL;
 448                         stats->tx_dropped++;
 449                         stats->tx_aborted_errors++;
 450                 }
 451         }
 452 }
 453
 454 /* Put the skb on the stack to be looped backed locally lateron
 455  *
 456  * The function is typically called in the start_xmit function
 457  * of the device driver. The driver must protect access to
 458  * priv->echo_skb, if necessary.
 459  */
 460 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 461                      unsigned int idx)
 462 {
 463         struct can_priv *priv = netdev_priv(dev);
 464
 465         BUG_ON(idx >= priv->echo_skb_max);
 466
 467         /* check flag whether this packet has to be looped back */
 468         if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
 469             (skb->protocol != htons(ETH_P_CAN) &&
 470              skb->protocol != htons(ETH_P_CANFD))) {
 471                 kfree_skb(skb);
 472                 return 0;
 473         }
 474
 475         if (!priv->echo_skb[idx]) {
 476                 skb = can_create_echo_skb(skb);
 477                 if (!skb)
 478                         return -ENOMEM;
 479
 480                 /* make settings for echo to reduce code in irq context */
 481                 skb->pkt_type = PACKET_BROADCAST;
 482                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 483                 skb->dev = dev;
 484
 485                 /* save this skb for tx interrupt echo handling */
 486                 priv->echo_skb[idx] = skb;
 487         } else {
 488                 /* locking problem with netif_stop_queue() ?? */
 489                 netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx);
 490                 kfree_skb(skb);
 491                 return -EBUSY;
 492         }
 493
 494         return 0;
 495 }
 496 EXPORT_SYMBOL_GPL(can_put_echo_skb);
 497
 498 struct sk_buff *
 499 __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
 500 {
 501         struct can_priv *priv = netdev_priv(dev);
 502
 503         if (idx >= priv->echo_skb_max) {
 504                 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
 505                            __func__, idx, priv->echo_skb_max);
 506                 return NULL;
 507         }
 508
 509         if (priv->echo_skb[idx]) {
 510                 /* Using "struct canfd_frame::len" for the frame
 511                  * length is supported on both CAN and CANFD frames.
 512                  */
 513                 struct sk_buff *skb = priv->echo_skb[idx];
 514                 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 515
 516                 /* get the real payload length for netdev statistics */
 517                 if (cf->can_id & CAN_RTR_FLAG)
 518                         *len_ptr = 0;
 519                 else
 520                         *len_ptr = cf->len;
 521
 522                 priv->echo_skb[idx] = NULL;
 523
 524                 return skb;
 525         }
 526
 527         return NULL;
 528 }
 529
 530 /* Get the skb from the stack and loop it back locally
 531  *
 532  * The function is typically called when the TX done interrupt
 533  * is handled in the device driver. The driver must protect
 534  * access to priv->echo_skb, if necessary.
 535  */
 536 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 537 {
 538         struct sk_buff *skb;
 539         u8 len;
 540
 541         skb = __can_get_echo_skb(dev, idx, &len);
 542         if (!skb)
 543                 return 0;
 544
 545         skb_get(skb);
 546         if (netif_rx(skb) == NET_RX_SUCCESS)
 547                 dev_consume_skb_any(skb);
 548         else
 549                 dev_kfree_skb_any(skb);
 550
 551         return len;
 552 }
 553 EXPORT_SYMBOL_GPL(can_get_echo_skb);
 554
 555 /* Remove the skb from the stack and free it.
 556  *
 557  * The function is typically called when TX failed.
 558  */
 559 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 560 {
 561         struct can_priv *priv = netdev_priv(dev);
 562
 563         BUG_ON(idx >= priv->echo_skb_max);
 564
 565         if (priv->echo_skb[idx]) {
 566                 dev_kfree_skb_any(priv->echo_skb[idx]);
 567                 priv->echo_skb[idx] = NULL;
 568         }
 569 }
 570 EXPORT_SYMBOL_GPL(can_free_echo_skb);
 571
 572 /* CAN device restart for bus-off recovery */
 573 static void can_restart(struct net_device *dev)
 574 {
 575         struct can_priv *priv = netdev_priv(dev);
 576         struct net_device_stats *stats = &dev->stats;
 577         struct sk_buff *skb;
 578         struct can_frame *cf;
 579         int err;
 580
 581         if (netif_carrier_ok(dev))
 582                 netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n");
 583
 584         /* No synchronization needed because the device is bus-off and
 585          * no messages can come in or go out.
 586          */
 587         can_flush_echo_skb(dev);
 588
 589         /* send restart message upstream */
 590         skb = alloc_can_err_skb(dev, &cf);
 591         if (!skb)
 592                 goto restart;
 593
 594         cf->can_id |= CAN_ERR_RESTARTED;
 595
 596         stats->rx_packets++;
 597         stats->rx_bytes += cf->can_dlc;
 598
 599         netif_rx_ni(skb);
 600
 601 restart:
 602         netdev_dbg(dev, "restarted\n");
 603         priv->can_stats.restarts++;
 604
 605         /* Now restart the device */
 606         netif_carrier_on(dev);
 607         err = priv->do_set_mode(dev, CAN_MODE_START);
 608         if (err) {
 609                 netdev_err(dev, "Error %d during restart", err);
 610                 netif_carrier_off(dev);
 611         }
 612 }
 613
 614 static void can_restart_work(struct work_struct *work)
 615 {
 616         struct delayed_work *dwork = to_delayed_work(work);
 617         struct can_priv *priv = container_of(dwork, struct can_priv,
 618                                              restart_work);
 619
 620         can_restart(priv->dev);
 621 }
 622
 623 int can_restart_now(struct net_device *dev)
 624 {
 625         struct can_priv *priv = netdev_priv(dev);
 626
 627         /* A manual restart is only permitted if automatic restart is
 628          * disabled and the device is in the bus-off state
 629          */
 630         if (priv->restart_ms)
 631                 return -EINVAL;
 632         if (priv->state != CAN_STATE_BUS_OFF)
 633                 return -EBUSY;
 634
 635         cancel_delayed_work_sync(&priv->restart_work);
 636         can_restart(dev);
 637
 638         return 0;
 639 }
 640
 641 /* CAN bus-off
 642  *
 643  * This functions should be called when the device goes bus-off to
 644  * tell the netif layer that no more packets can be sent or received.
 645  * If enabled, a timer is started to trigger bus-off recovery.
 646  */
 647 void can_bus_off(struct net_device *dev)
 648 {
 649         struct can_priv *priv = netdev_priv(dev);
 650
 651         if (priv->restart_ms)
 652                 netdev_info(dev, "bus-off, scheduling restart in %d ms\n",
 653                             priv->restart_ms);
 654         else
 655                 netdev_info(dev, "bus-off\n");
 656
 657         netif_carrier_off(dev);
 658
 659         if (priv->restart_ms)
 660                 schedule_delayed_work(&priv->restart_work,
 661                                       msecs_to_jiffies(priv->restart_ms));
 662 }
 663 EXPORT_SYMBOL_GPL(can_bus_off);
 664
 665 static void can_setup(struct net_device *dev)
 666 {
 667         dev->type = ARPHRD_CAN;
 668         dev->mtu = CAN_MTU;
 669         dev->hard_header_len = 0;
 670         dev->addr_len = 0;
 671         dev->tx_queue_len = 10;
 672
 673         /* New-style flags. */
 674         dev->flags = IFF_NOARP;
 675         dev->features = NETIF_F_HW_CSUM;
 676 }
 677
 678 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 679 {
 680         struct sk_buff *skb;
 681
 682         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 683                                sizeof(struct can_frame));
 684         if (unlikely(!skb))
 685                 return NULL;
 686
 687         skb->protocol = htons(ETH_P_CAN);
 688         skb->pkt_type = PACKET_BROADCAST;
 689         skb->ip_summed = CHECKSUM_UNNECESSARY;
 690
 691         skb_reset_mac_header(skb);
 692         skb_reset_network_header(skb);
 693         skb_reset_transport_header(skb);
 694
 695         can_skb_reserve(skb);
 696         can_skb_prv(skb)->ifindex = dev->ifindex;
 697         can_skb_prv(skb)->skbcnt = 0;
 698
 699         *cf = skb_put_zero(skb, sizeof(struct can_frame));
 700
 701         return skb;
 702 }
 703 EXPORT_SYMBOL_GPL(alloc_can_skb);
 704
 705 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 706                                 struct canfd_frame **cfd)
 707 {
 708         struct sk_buff *skb;
 709
 710         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 711                                sizeof(struct canfd_frame));
 712         if (unlikely(!skb))
 713                 return NULL;
 714
 715         skb->protocol = htons(ETH_P_CANFD);
 716         skb->pkt_type = PACKET_BROADCAST;
 717         skb->ip_summed = CHECKSUM_UNNECESSARY;
 718
 719         skb_reset_mac_header(skb);
 720         skb_reset_network_header(skb);
 721         skb_reset_transport_header(skb);
 722
 723         can_skb_reserve(skb);
 724         can_skb_prv(skb)->ifindex = dev->ifindex;
 725         can_skb_prv(skb)->skbcnt = 0;
 726
 727         *cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
 728
 729         return skb;
 730 }
 731 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
 732
 733 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 734 {
 735         struct sk_buff *skb;
 736
 737         skb = alloc_can_skb(dev, cf);
 738         if (unlikely(!skb))
 739                 return NULL;
 740
 741         (*cf)->can_id = CAN_ERR_FLAG;
 742         (*cf)->can_dlc = CAN_ERR_DLC;
 743
 744         return skb;
 745 }
 746 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
 747
 748 /* Allocate and setup space for the CAN network device */
 749 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 750                                     unsigned int txqs, unsigned int rxqs)
 751 {
 752         struct can_ml_priv *can_ml;
 753         struct net_device *dev;
 754         struct can_priv *priv;
 755         int size;
 756
 757         /* We put the driver's priv, the CAN mid layer priv and the
 758          * echo skb into the netdevice's priv. The memory layout for
 759          * the netdev_priv is like this:
 760          *
 761          * +-------------------------+
 762          * | driver's priv           |
 763          * +-------------------------+
 764          * | struct can_ml_priv      |
 765          * +-------------------------+
 766          * | array of struct sk_buff |
 767          * +-------------------------+
 768          */
 769
 770         size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv);
 771
 772         if (echo_skb_max)
 773                 size = ALIGN(size, sizeof(struct sk_buff *)) +
 774                         echo_skb_max * sizeof(struct sk_buff *);
 775
 776         dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
 777                                txqs, rxqs);
 778         if (!dev)
 779                 return NULL;
 780
 781         priv = netdev_priv(dev);
 782         priv->dev = dev;
 783
 784         can_ml = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN);
 785         can_set_ml_priv(dev, can_ml);
 786
 787         if (echo_skb_max) {
 788                 priv->echo_skb_max = echo_skb_max;
 789                 priv->echo_skb = (void *)priv +
 790                         (size - echo_skb_max * sizeof(struct sk_buff *));
 791         }
 792
 793         priv->state = CAN_STATE_STOPPED;
 794
 795         INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
 796
 797         return dev;
 798 }
 799 EXPORT_SYMBOL_GPL(alloc_candev_mqs);
 800
 801 /* Free space of the CAN network device */
 802 void free_candev(struct net_device *dev)
 803 {
 804         free_netdev(dev);
 805 }
 806 EXPORT_SYMBOL_GPL(free_candev);
 807
 808 /* changing MTU and control mode for CAN/CANFD devices */
 809 int can_change_mtu(struct net_device *dev, int new_mtu)
 810 {
 811         struct can_priv *priv = netdev_priv(dev);
 812
 813         /* Do not allow changing the MTU while running */
 814         if (dev->flags & IFF_UP)
 815                 return -EBUSY;
 816
 817         /* allow change of MTU according to the CANFD ability of the device */
 818         switch (new_mtu) {
 819         case CAN_MTU:
 820                 /* 'CANFD-only' controllers can not switch to CAN_MTU */
 821                 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
 822                         return -EINVAL;
 823
 824                 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
 825                 break;
 826
 827         case CANFD_MTU:
 828                 /* check for potential CANFD ability */
 829                 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
 830                     !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
 831                         return -EINVAL;
 832
 833                 priv->ctrlmode |= CAN_CTRLMODE_FD;
 834                 break;
 835
 836         default:
 837                 return -EINVAL;
 838         }
 839
 840         dev->mtu = new_mtu;
 841         return 0;
 842 }
 843 EXPORT_SYMBOL_GPL(can_change_mtu);
 844
 845 /* Common open function when the device gets opened.
 846  *
 847  * This function should be called in the open function of the device
 848  * driver.
 849  */
 850 int open_candev(struct net_device *dev)
 851 {
 852         struct can_priv *priv = netdev_priv(dev);
 853
 854         if (!priv->bittiming.bitrate) {
 855                 netdev_err(dev, "bit-timing not yet defined\n");
 856                 return -EINVAL;
 857         }
 858
 859         /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
 860         if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
 861             (!priv->data_bittiming.bitrate ||
 862              priv->data_bittiming.bitrate < priv->bittiming.bitrate)) {
 863                 netdev_err(dev, "incorrect/missing data bit-timing\n");
 864                 return -EINVAL;
 865         }
 866
 867         /* Switch carrier on if device was stopped while in bus-off state */
 868         if (!netif_carrier_ok(dev))
 869                 netif_carrier_on(dev);
 870
 871         return 0;
 872 }
 873 EXPORT_SYMBOL_GPL(open_candev);
 874
 875 #ifdef CONFIG_OF
 876 /* Common function that can be used to understand the limitation of
 877  * a transceiver when it provides no means to determine these limitations
 878  * at runtime.
 879  */
 880 void of_can_transceiver(struct net_device *dev)
 881 {
 882         struct device_node *dn;
 883         struct can_priv *priv = netdev_priv(dev);
 884         struct device_node *np = dev->dev.parent->of_node;
 885         int ret;
 886
 887         dn = of_get_child_by_name(np, "can-transceiver");
 888         if (!dn)
 889                 return;
 890
 891         ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
 892         of_node_put(dn);
 893         if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
 894                 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
 895 }
 896 EXPORT_SYMBOL_GPL(of_can_transceiver);
 897 #endif
 898
 899 /* Common close function for cleanup before the device gets closed.
 900  *
 901  * This function should be called in the close function of the device
 902  * driver.
 903  */
 904 void close_candev(struct net_device *dev)
 905 {
 906         struct can_priv *priv = netdev_priv(dev);
 907
 908         cancel_delayed_work_sync(&priv->restart_work);
 909         can_flush_echo_skb(dev);
 910 }
 911 EXPORT_SYMBOL_GPL(close_candev);
 912
 913 /* CAN netlink interface */
 914 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 915         [IFLA_CAN_STATE]        = { .type = NLA_U32 },
 916         [IFLA_CAN_CTRLMODE]     = { .len = sizeof(struct can_ctrlmode) },
 917         [IFLA_CAN_RESTART_MS]   = { .type = NLA_U32 },
 918         [IFLA_CAN_RESTART]      = { .type = NLA_U32 },
 919         [IFLA_CAN_BITTIMING]    = { .len = sizeof(struct can_bittiming) },
 920         [IFLA_CAN_BITTIMING_CONST]
 921                                 = { .len = sizeof(struct can_bittiming_const) },
 922         [IFLA_CAN_CLOCK]        = { .len = sizeof(struct can_clock) },
 923         [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 924         [IFLA_CAN_DATA_BITTIMING]
 925                                 = { .len = sizeof(struct can_bittiming) },
 926         [IFLA_CAN_DATA_BITTIMING_CONST]
 927                                 = { .len = sizeof(struct can_bittiming_const) },
 928         [IFLA_CAN_TERMINATION]  = { .type = NLA_U16 },
 929 };
 930
 931 static int can_validate(struct nlattr *tb[], struct nlattr *data[],
 932                         struct netlink_ext_ack *extack)
 933 {
 934         bool is_can_fd = false;
 935
 936         /* Make sure that valid CAN FD configurations always consist of
 937          * - nominal/arbitration bittiming
 938          * - data bittiming
 939          * - control mode with CAN_CTRLMODE_FD set
 940          */
 941
 942         if (!data)
 943                 return 0;
 944
 945         if (data[IFLA_CAN_CTRLMODE]) {
 946                 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 947
 948                 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
 949         }
 950
 951         if (is_can_fd) {
 952                 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
 953                         return -EOPNOTSUPP;
 954         }
 955
 956         if (data[IFLA_CAN_DATA_BITTIMING]) {
 957                 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
 958                         return -EOPNOTSUPP;
 959         }
 960
 961         return 0;
 962 }
 963
 964 static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 965                           struct nlattr *data[],
 966                           struct netlink_ext_ack *extack)
 967 {
 968         struct can_priv *priv = netdev_priv(dev);
 969         int err;
 970
 971         /* We need synchronization with dev->stop() */
 972         ASSERT_RTNL();
 973
 974         if (data[IFLA_CAN_BITTIMING]) {
 975                 struct can_bittiming bt;
 976
 977                 /* Do not allow changing bittiming while running */
 978                 if (dev->flags & IFF_UP)
 979                         return -EBUSY;
 980
 981                 /* Calculate bittiming parameters based on
 982                  * bittiming_const if set, otherwise pass bitrate
 983                  * directly via do_set_bitrate(). Bail out if neither
 984                  * is given.
 985                  */
 986                 if (!priv->bittiming_const && !priv->do_set_bittiming)
 987                         return -EOPNOTSUPP;
 988
 989                 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
 990                 err = can_get_bittiming(dev, &bt,
 991                                         priv->bittiming_const,
 992                                         priv->bitrate_const,
 993                                         priv->bitrate_const_cnt);
 994                 if (err)
 995                         return err;
 996
 997                 if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
 998                         netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
 999                                    priv->bitrate_max);
1000                         return -EINVAL;
1001                 }
1002
1003                 memcpy(&priv->bittiming, &bt, sizeof(bt));
1004
1005                 if (priv->do_set_bittiming) {
1006                         /* Finally, set the bit-timing registers */
1007                         err = priv->do_set_bittiming(dev);
1008                         if (err)
1009                                 return err;
1010                 }
1011         }
1012
1013         if (data[IFLA_CAN_CTRLMODE]) {
1014                 struct can_ctrlmode *cm;
1015                 u32 ctrlstatic;
1016                 u32 maskedflags;
1017
1018                 /* Do not allow changing controller mode while running */
1019                 if (dev->flags & IFF_UP)
1020                         return -EBUSY;
1021                 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
1022                 ctrlstatic = priv->ctrlmode_static;
1023                 maskedflags = cm->flags & cm->mask;
1024
1025                 /* check whether provided bits are allowed to be passed */
1026                 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
1027                         return -EOPNOTSUPP;
1028
1029                 /* do not check for static fd-non-iso if 'fd' is disabled */
1030                 if (!(maskedflags & CAN_CTRLMODE_FD))
1031                         ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
1032
1033                 /* make sure static options are provided by configuration */
1034                 if ((maskedflags & ctrlstatic) != ctrlstatic)
1035                         return -EOPNOTSUPP;
1036
1037                 /* clear bits to be modified and copy the flag values */
1038                 priv->ctrlmode &= ~cm->mask;
1039                 priv->ctrlmode |= maskedflags;
1040
1041                 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
1042                 if (priv->ctrlmode & CAN_CTRLMODE_FD)
1043                         dev->mtu = CANFD_MTU;
1044                 else
1045                         dev->mtu = CAN_MTU;
1046         }
1047
1048         if (data[IFLA_CAN_RESTART_MS]) {
1049                 /* Do not allow changing restart delay while running */
1050                 if (dev->flags & IFF_UP)
1051                         return -EBUSY;
1052                 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
1053         }
1054
1055         if (data[IFLA_CAN_RESTART]) {
1056                 /* Do not allow a restart while not running */
1057                 if (!(dev->flags & IFF_UP))
1058                         return -EINVAL;
1059                 err = can_restart_now(dev);
1060                 if (err)
1061                         return err;
1062         }
1063
1064         if (data[IFLA_CAN_DATA_BITTIMING]) {
1065                 struct can_bittiming dbt;
1066
1067                 /* Do not allow changing bittiming while running */
1068                 if (dev->flags & IFF_UP)
1069                         return -EBUSY;
1070
1071                 /* Calculate bittiming parameters based on
1072                  * data_bittiming_const if set, otherwise pass bitrate
1073                  * directly via do_set_bitrate(). Bail out if neither
1074                  * is given.
1075                  */
1076                 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
1077                         return -EOPNOTSUPP;
1078
1079                 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
1080                        sizeof(dbt));
1081                 err = can_get_bittiming(dev, &dbt,
1082                                         priv->data_bittiming_const,
1083                                         priv->data_bitrate_const,
1084                                         priv->data_bitrate_const_cnt);
1085                 if (err)
1086                         return err;
1087
1088                 if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
1089                         netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
1090                                    priv->bitrate_max);
1091                         return -EINVAL;
1092                 }
1093
1094                 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
1095
1096                 if (priv->do_set_data_bittiming) {
1097                         /* Finally, set the bit-timing registers */
1098                         err = priv->do_set_data_bittiming(dev);
1099                         if (err)
1100                                 return err;
1101                 }
1102         }
1103
1104         if (data[IFLA_CAN_TERMINATION]) {
1105                 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
1106                 const unsigned int num_term = priv->termination_const_cnt;
1107                 unsigned int i;
1108
1109                 if (!priv->do_set_termination)
1110                         return -EOPNOTSUPP;
1111
1112                 /* check whether given value is supported by the interface */
1113                 for (i = 0; i < num_term; i++) {
1114                         if (termval == priv->termination_const[i])
1115                                 break;
1116                 }
1117                 if (i >= num_term)
1118                         return -EINVAL;
1119
1120                 /* Finally, set the termination value */
1121                 err = priv->do_set_termination(dev, termval);
1122                 if (err)
1123                         return err;
1124
1125                 priv->termination = termval;
1126         }
1127
1128         return 0;
1129 }
1130
1131 static size_t can_get_size(const struct net_device *dev)
1132 {
1133         struct can_priv *priv = netdev_priv(dev);
1134         size_t size = 0;
1135
1136         if (priv->bittiming.bitrate)                            /* IFLA_CAN_BITTIMING */
1137                 size += nla_total_size(sizeof(struct can_bittiming));
1138         if (priv->bittiming_const)                              /* IFLA_CAN_BITTIMING_CONST */
1139                 size += nla_total_size(sizeof(struct can_bittiming_const));
1140         size += nla_total_size(sizeof(struct can_clock));       /* IFLA_CAN_CLOCK */
1141         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_STATE */
1142         size += nla_total_size(sizeof(struct can_ctrlmode));    /* IFLA_CAN_CTRLMODE */
1143         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_RESTART_MS */
1144         if (priv->do_get_berr_counter)                          /* IFLA_CAN_BERR_COUNTER */
1145                 size += nla_total_size(sizeof(struct can_berr_counter));
1146         if (priv->data_bittiming.bitrate)                       /* IFLA_CAN_DATA_BITTIMING */
1147                 size += nla_total_size(sizeof(struct can_bittiming));
1148         if (priv->data_bittiming_const)                         /* IFLA_CAN_DATA_BITTIMING_CONST */
1149                 size += nla_total_size(sizeof(struct can_bittiming_const));
1150         if (priv->termination_const) {
1151                 size += nla_total_size(sizeof(priv->termination));              /* IFLA_CAN_TERMINATION */
1152                 size += nla_total_size(sizeof(*priv->termination_const) *       /* IFLA_CAN_TERMINATION_CONST */
1153                                        priv->termination_const_cnt);
1154         }
1155         if (priv->bitrate_const)                                /* IFLA_CAN_BITRATE_CONST */
1156                 size += nla_total_size(sizeof(*priv->bitrate_const) *
1157                                        priv->bitrate_const_cnt);
1158         if (priv->data_bitrate_const)                           /* IFLA_CAN_DATA_BITRATE_CONST */
1159                 size += nla_total_size(sizeof(*priv->data_bitrate_const) *
1160                                        priv->data_bitrate_const_cnt);
1161         size += sizeof(priv->bitrate_max);                      /* IFLA_CAN_BITRATE_MAX */
1162
1163         return size;
1164 }
1165
1166 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1167 {
1168         struct can_priv *priv = netdev_priv(dev);
1169         struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1170         struct can_berr_counter bec = { };
1171         enum can_state state = priv->state;
1172
1173         if (priv->do_get_state)
1174                 priv->do_get_state(dev, &state);
1175
1176         if ((priv->bittiming.bitrate &&
1177              nla_put(skb, IFLA_CAN_BITTIMING,
1178                      sizeof(priv->bittiming), &priv->bittiming)) ||
1179
1180             (priv->bittiming_const &&
1181              nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1182                      sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1183
1184             nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1185             nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1186             nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1187             nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1188
1189             (priv->do_get_berr_counter &&
1190              !priv->do_get_berr_counter(dev, &bec) &&
1191              nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1192
1193             (priv->data_bittiming.bitrate &&
1194              nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1195                      sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1196
1197             (priv->data_bittiming_const &&
1198              nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1199                      sizeof(*priv->data_bittiming_const),
1200                      priv->data_bittiming_const)) ||
1201
1202             (priv->termination_const &&
1203              (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
1204               nla_put(skb, IFLA_CAN_TERMINATION_CONST,
1205                       sizeof(*priv->termination_const) *
1206                       priv->termination_const_cnt,
1207                       priv->termination_const))) ||
1208
1209             (priv->bitrate_const &&
1210              nla_put(skb, IFLA_CAN_BITRATE_CONST,
1211                      sizeof(*priv->bitrate_const) *
1212                      priv->bitrate_const_cnt,
1213                      priv->bitrate_const)) ||
1214
1215             (priv->data_bitrate_const &&
1216              nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
1217                      sizeof(*priv->data_bitrate_const) *
1218                      priv->data_bitrate_const_cnt,
1219                      priv->data_bitrate_const)) ||
1220
1221             (nla_put(skb, IFLA_CAN_BITRATE_MAX,
1222                      sizeof(priv->bitrate_max),
1223                      &priv->bitrate_max))
1224             )
1225
1226                 return -EMSGSIZE;
1227
1228         return 0;
1229 }
1230
1231 static size_t can_get_xstats_size(const struct net_device *dev)
1232 {
1233         return sizeof(struct can_device_stats);
1234 }
1235
1236 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1237 {
1238         struct can_priv *priv = netdev_priv(dev);
1239
1240         if (nla_put(skb, IFLA_INFO_XSTATS,
1241                     sizeof(priv->can_stats), &priv->can_stats))
1242                 goto nla_put_failure;
1243         return 0;
1244
1245 nla_put_failure:
1246         return -EMSGSIZE;
1247 }
1248
1249 static int can_newlink(struct net *src_net, struct net_device *dev,
1250                        struct nlattr *tb[], struct nlattr *data[],
1251                        struct netlink_ext_ack *extack)
1252 {
1253         return -EOPNOTSUPP;
1254 }
1255
1256 static void can_dellink(struct net_device *dev, struct list_head *head)
1257 {
1258 }
1259
1260 static struct rtnl_link_ops can_link_ops __read_mostly = {
1261         .kind           = "can",
1262         .netns_refund   = true,
1263         .maxtype        = IFLA_CAN_MAX,
1264         .policy         = can_policy,
1265         .setup          = can_setup,
1266         .validate       = can_validate,
1267         .newlink        = can_newlink,
1268         .changelink     = can_changelink,
1269         .dellink        = can_dellink,
1270         .get_size       = can_get_size,
1271         .fill_info      = can_fill_info,
1272         .get_xstats_size = can_get_xstats_size,
1273         .fill_xstats    = can_fill_xstats,
1274 };
1275
1276 /* Register the CAN network device */
1277 int register_candev(struct net_device *dev)
1278 {
1279         struct can_priv *priv = netdev_priv(dev);
1280
1281         /* Ensure termination_const, termination_const_cnt and
1282          * do_set_termination consistency. All must be either set or
1283          * unset.
1284          */
1285         if ((!priv->termination_const != !priv->termination_const_cnt) ||
1286             (!priv->termination_const != !priv->do_set_termination))
1287                 return -EINVAL;
1288
1289         if (!priv->bitrate_const != !priv->bitrate_const_cnt)
1290                 return -EINVAL;
1291
1292         if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
1293                 return -EINVAL;
1294
1295         dev->rtnl_link_ops = &can_link_ops;
1296         netif_carrier_off(dev);
1297
1298         return register_netdev(dev);
1299 }
1300 EXPORT_SYMBOL_GPL(register_candev);
1301
1302 /* Unregister the CAN network device */
1303 void unregister_candev(struct net_device *dev)
1304 {
1305         unregister_netdev(dev);
1306 }
1307 EXPORT_SYMBOL_GPL(unregister_candev);
1308
1309 /* Test if a network device is a candev based device
1310  * and return the can_priv* if so.
1311  */
1312 struct can_priv *safe_candev_priv(struct net_device *dev)
1313 {
1314         if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops)
1315                 return NULL;
1316
1317         return netdev_priv(dev);
1318 }
1319 EXPORT_SYMBOL_GPL(safe_candev_priv);
1320
1321 static __init int can_dev_init(void)
1322 {
1323         int err;
1324
1325         can_led_notifier_init();
1326
1327         err = rtnl_link_register(&can_link_ops);
1328         if (!err)
1329                 pr_info(MOD_DESC "\n");
1330
1331         return err;
1332 }
1333 module_init(can_dev_init);
1334
1335 static __exit void can_dev_exit(void)
1336 {
1337         rtnl_link_unregister(&can_link_ops);
1338
1339         can_led_notifier_exit();
1340 }
1341 module_exit(can_dev_exit);
1342
1343 MODULE_ALIAS_RTNL_LINK("can");