dev.c revision 1e0625facab2e871472472b7df87d8fbe6caf75a
1/* 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 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the version 2 of the GNU General Public License 8 * as published by the Free Software Foundation 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20#include <linux/module.h> 21#include <linux/kernel.h> 22#include <linux/slab.h> 23#include <linux/netdevice.h> 24#include <linux/if_arp.h> 25#include <linux/can.h> 26#include <linux/can/dev.h> 27#include <linux/can/netlink.h> 28#include <net/rtnetlink.h> 29 30#define MOD_DESC "CAN device driver interface" 31 32MODULE_DESCRIPTION(MOD_DESC); 33MODULE_LICENSE("GPL v2"); 34MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 35 36/* CAN DLC to real data length conversion helpers */ 37 38static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7, 39 8, 12, 16, 20, 24, 32, 48, 64}; 40 41/* get data length from can_dlc with sanitized can_dlc */ 42u8 can_dlc2len(u8 can_dlc) 43{ 44 return dlc2len[can_dlc & 0x0F]; 45} 46EXPORT_SYMBOL_GPL(can_dlc2len); 47 48static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */ 49 9, 9, 9, 9, /* 9 - 12 */ 50 10, 10, 10, 10, /* 13 - 16 */ 51 11, 11, 11, 11, /* 17 - 20 */ 52 12, 12, 12, 12, /* 21 - 24 */ 53 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ 54 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ 55 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ 56 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ 57 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */ 58 59/* map the sanitized data length to an appropriate data length code */ 60u8 can_len2dlc(u8 len) 61{ 62 if (unlikely(len > 64)) 63 return 0xF; 64 65 return len2dlc[len]; 66} 67EXPORT_SYMBOL_GPL(can_len2dlc); 68 69#ifdef CONFIG_CAN_CALC_BITTIMING 70#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ 71 72/* 73 * Bit-timing calculation derived from: 74 * 75 * Code based on LinCAN sources and H8S2638 project 76 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz 77 * Copyright 2005 Stanislav Marek 78 * email: pisa@cmp.felk.cvut.cz 79 * 80 * Calculates proper bit-timing parameters for a specified bit-rate 81 * and sample-point, which can then be used to set the bit-timing 82 * registers of the CAN controller. You can find more information 83 * in the header file linux/can/netlink.h. 84 */ 85static int can_update_spt(const struct can_bittiming_const *btc, 86 int sampl_pt, int tseg, int *tseg1, int *tseg2) 87{ 88 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000; 89 if (*tseg2 < btc->tseg2_min) 90 *tseg2 = btc->tseg2_min; 91 if (*tseg2 > btc->tseg2_max) 92 *tseg2 = btc->tseg2_max; 93 *tseg1 = tseg - *tseg2; 94 if (*tseg1 > btc->tseg1_max) { 95 *tseg1 = btc->tseg1_max; 96 *tseg2 = tseg - *tseg1; 97 } 98 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1); 99} 100 101static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 102{ 103 struct can_priv *priv = netdev_priv(dev); 104 const struct can_bittiming_const *btc = priv->bittiming_const; 105 long rate, best_rate = 0; 106 long best_error = 1000000000, error = 0; 107 int best_tseg = 0, best_brp = 0, brp = 0; 108 int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0; 109 int spt_error = 1000, spt = 0, sampl_pt; 110 u64 v64; 111 112 if (!priv->bittiming_const) 113 return -ENOTSUPP; 114 115 /* Use CIA recommended sample points */ 116 if (bt->sample_point) { 117 sampl_pt = bt->sample_point; 118 } else { 119 if (bt->bitrate > 800000) 120 sampl_pt = 750; 121 else if (bt->bitrate > 500000) 122 sampl_pt = 800; 123 else 124 sampl_pt = 875; 125 } 126 127 /* tseg even = round down, odd = round up */ 128 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; 129 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { 130 tsegall = 1 + tseg / 2; 131 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ 132 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; 133 /* chose brp step which is possible in system */ 134 brp = (brp / btc->brp_inc) * btc->brp_inc; 135 if ((brp < btc->brp_min) || (brp > btc->brp_max)) 136 continue; 137 rate = priv->clock.freq / (brp * tsegall); 138 error = bt->bitrate - rate; 139 /* tseg brp biterror */ 140 if (error < 0) 141 error = -error; 142 if (error > best_error) 143 continue; 144 best_error = error; 145 if (error == 0) { 146 spt = can_update_spt(btc, sampl_pt, tseg / 2, 147 &tseg1, &tseg2); 148 error = sampl_pt - spt; 149 if (error < 0) 150 error = -error; 151 if (error > spt_error) 152 continue; 153 spt_error = error; 154 } 155 best_tseg = tseg / 2; 156 best_brp = brp; 157 best_rate = rate; 158 if (error == 0) 159 break; 160 } 161 162 if (best_error) { 163 /* Error in one-tenth of a percent */ 164 error = (best_error * 1000) / bt->bitrate; 165 if (error > CAN_CALC_MAX_ERROR) { 166 netdev_err(dev, 167 "bitrate error %ld.%ld%% too high\n", 168 error / 10, error % 10); 169 return -EDOM; 170 } else { 171 netdev_warn(dev, "bitrate error %ld.%ld%%\n", 172 error / 10, error % 10); 173 } 174 } 175 176 /* real sample point */ 177 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, 178 &tseg1, &tseg2); 179 180 v64 = (u64)best_brp * 1000000000UL; 181 do_div(v64, priv->clock.freq); 182 bt->tq = (u32)v64; 183 bt->prop_seg = tseg1 / 2; 184 bt->phase_seg1 = tseg1 - bt->prop_seg; 185 bt->phase_seg2 = tseg2; 186 187 /* check for sjw user settings */ 188 if (!bt->sjw || !btc->sjw_max) 189 bt->sjw = 1; 190 else { 191 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ 192 if (bt->sjw > btc->sjw_max) 193 bt->sjw = btc->sjw_max; 194 /* bt->sjw must not be higher than tseg2 */ 195 if (tseg2 < bt->sjw) 196 bt->sjw = tseg2; 197 } 198 199 bt->brp = best_brp; 200 /* real bit-rate */ 201 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); 202 203 return 0; 204} 205#else /* !CONFIG_CAN_CALC_BITTIMING */ 206static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 207{ 208 netdev_err(dev, "bit-timing calculation not available\n"); 209 return -EINVAL; 210} 211#endif /* CONFIG_CAN_CALC_BITTIMING */ 212 213/* 214 * Checks the validity of the specified bit-timing parameters prop_seg, 215 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 216 * prescaler value brp. You can find more information in the header 217 * file linux/can/netlink.h. 218 */ 219static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt) 220{ 221 struct can_priv *priv = netdev_priv(dev); 222 const struct can_bittiming_const *btc = priv->bittiming_const; 223 int tseg1, alltseg; 224 u64 brp64; 225 226 if (!priv->bittiming_const) 227 return -ENOTSUPP; 228 229 tseg1 = bt->prop_seg + bt->phase_seg1; 230 if (!bt->sjw) 231 bt->sjw = 1; 232 if (bt->sjw > btc->sjw_max || 233 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 234 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 235 return -ERANGE; 236 237 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 238 if (btc->brp_inc > 1) 239 do_div(brp64, btc->brp_inc); 240 brp64 += 500000000UL - 1; 241 do_div(brp64, 1000000000UL); /* the practicable BRP */ 242 if (btc->brp_inc > 1) 243 brp64 *= btc->brp_inc; 244 bt->brp = (u32)brp64; 245 246 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 247 return -EINVAL; 248 249 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 250 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 251 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 252 253 return 0; 254} 255 256static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt) 257{ 258 struct can_priv *priv = netdev_priv(dev); 259 int err; 260 261 /* Check if the CAN device has bit-timing parameters */ 262 if (priv->bittiming_const) { 263 264 /* Non-expert mode? Check if the bitrate has been pre-defined */ 265 if (!bt->tq) 266 /* Determine bit-timing parameters */ 267 err = can_calc_bittiming(dev, bt); 268 else 269 /* Check bit-timing params and calculate proper brp */ 270 err = can_fixup_bittiming(dev, bt); 271 if (err) 272 return err; 273 } 274 275 return 0; 276} 277 278/* 279 * Local echo of CAN messages 280 * 281 * CAN network devices *should* support a local echo functionality 282 * (see Documentation/networking/can.txt). To test the handling of CAN 283 * interfaces that do not support the local echo both driver types are 284 * implemented. In the case that the driver does not support the echo 285 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 286 * to perform the echo as a fallback solution. 287 */ 288static void can_flush_echo_skb(struct net_device *dev) 289{ 290 struct can_priv *priv = netdev_priv(dev); 291 struct net_device_stats *stats = &dev->stats; 292 int i; 293 294 for (i = 0; i < priv->echo_skb_max; i++) { 295 if (priv->echo_skb[i]) { 296 kfree_skb(priv->echo_skb[i]); 297 priv->echo_skb[i] = NULL; 298 stats->tx_dropped++; 299 stats->tx_aborted_errors++; 300 } 301 } 302} 303 304/* 305 * Put the skb on the stack to be looped backed locally lateron 306 * 307 * The function is typically called in the start_xmit function 308 * of the device driver. The driver must protect access to 309 * priv->echo_skb, if necessary. 310 */ 311void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 312 unsigned int idx) 313{ 314 struct can_priv *priv = netdev_priv(dev); 315 316 BUG_ON(idx >= priv->echo_skb_max); 317 318 /* check flag whether this packet has to be looped back */ 319 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) { 320 kfree_skb(skb); 321 return; 322 } 323 324 if (!priv->echo_skb[idx]) { 325 struct sock *srcsk = skb->sk; 326 327 if (atomic_read(&skb->users) != 1) { 328 struct sk_buff *old_skb = skb; 329 330 skb = skb_clone(old_skb, GFP_ATOMIC); 331 kfree_skb(old_skb); 332 if (!skb) 333 return; 334 } else 335 skb_orphan(skb); 336 337 skb->sk = srcsk; 338 339 /* make settings for echo to reduce code in irq context */ 340 skb->protocol = htons(ETH_P_CAN); 341 skb->pkt_type = PACKET_BROADCAST; 342 skb->ip_summed = CHECKSUM_UNNECESSARY; 343 skb->dev = dev; 344 345 /* save this skb for tx interrupt echo handling */ 346 priv->echo_skb[idx] = skb; 347 } else { 348 /* locking problem with netif_stop_queue() ?? */ 349 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); 350 kfree_skb(skb); 351 } 352} 353EXPORT_SYMBOL_GPL(can_put_echo_skb); 354 355/* 356 * Get the skb from the stack and loop it back locally 357 * 358 * The function is typically called when the TX done interrupt 359 * is handled in the device driver. The driver must protect 360 * access to priv->echo_skb, if necessary. 361 */ 362unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 363{ 364 struct can_priv *priv = netdev_priv(dev); 365 366 BUG_ON(idx >= priv->echo_skb_max); 367 368 if (priv->echo_skb[idx]) { 369 struct sk_buff *skb = priv->echo_skb[idx]; 370 struct can_frame *cf = (struct can_frame *)skb->data; 371 u8 dlc = cf->can_dlc; 372 373 netif_rx(priv->echo_skb[idx]); 374 priv->echo_skb[idx] = NULL; 375 376 return dlc; 377 } 378 379 return 0; 380} 381EXPORT_SYMBOL_GPL(can_get_echo_skb); 382 383/* 384 * Remove the skb from the stack and free it. 385 * 386 * The function is typically called when TX failed. 387 */ 388void can_free_echo_skb(struct net_device *dev, unsigned int idx) 389{ 390 struct can_priv *priv = netdev_priv(dev); 391 392 BUG_ON(idx >= priv->echo_skb_max); 393 394 if (priv->echo_skb[idx]) { 395 kfree_skb(priv->echo_skb[idx]); 396 priv->echo_skb[idx] = NULL; 397 } 398} 399EXPORT_SYMBOL_GPL(can_free_echo_skb); 400 401/* 402 * CAN device restart for bus-off recovery 403 */ 404void can_restart(unsigned long data) 405{ 406 struct net_device *dev = (struct net_device *)data; 407 struct can_priv *priv = netdev_priv(dev); 408 struct net_device_stats *stats = &dev->stats; 409 struct sk_buff *skb; 410 struct can_frame *cf; 411 int err; 412 413 BUG_ON(netif_carrier_ok(dev)); 414 415 /* 416 * No synchronization needed because the device is bus-off and 417 * no messages can come in or go out. 418 */ 419 can_flush_echo_skb(dev); 420 421 /* send restart message upstream */ 422 skb = alloc_can_err_skb(dev, &cf); 423 if (skb == NULL) { 424 err = -ENOMEM; 425 goto restart; 426 } 427 cf->can_id |= CAN_ERR_RESTARTED; 428 429 netif_rx(skb); 430 431 stats->rx_packets++; 432 stats->rx_bytes += cf->can_dlc; 433 434restart: 435 netdev_dbg(dev, "restarted\n"); 436 priv->can_stats.restarts++; 437 438 /* Now restart the device */ 439 err = priv->do_set_mode(dev, CAN_MODE_START); 440 441 netif_carrier_on(dev); 442 if (err) 443 netdev_err(dev, "Error %d during restart", err); 444} 445 446int can_restart_now(struct net_device *dev) 447{ 448 struct can_priv *priv = netdev_priv(dev); 449 450 /* 451 * A manual restart is only permitted if automatic restart is 452 * disabled and the device is in the bus-off state 453 */ 454 if (priv->restart_ms) 455 return -EINVAL; 456 if (priv->state != CAN_STATE_BUS_OFF) 457 return -EBUSY; 458 459 /* Runs as soon as possible in the timer context */ 460 mod_timer(&priv->restart_timer, jiffies); 461 462 return 0; 463} 464 465/* 466 * CAN bus-off 467 * 468 * This functions should be called when the device goes bus-off to 469 * tell the netif layer that no more packets can be sent or received. 470 * If enabled, a timer is started to trigger bus-off recovery. 471 */ 472void can_bus_off(struct net_device *dev) 473{ 474 struct can_priv *priv = netdev_priv(dev); 475 476 netdev_dbg(dev, "bus-off\n"); 477 478 netif_carrier_off(dev); 479 priv->can_stats.bus_off++; 480 481 if (priv->restart_ms) 482 mod_timer(&priv->restart_timer, 483 jiffies + (priv->restart_ms * HZ) / 1000); 484} 485EXPORT_SYMBOL_GPL(can_bus_off); 486 487static void can_setup(struct net_device *dev) 488{ 489 dev->type = ARPHRD_CAN; 490 dev->mtu = CAN_MTU; 491 dev->hard_header_len = 0; 492 dev->addr_len = 0; 493 dev->tx_queue_len = 10; 494 495 /* New-style flags. */ 496 dev->flags = IFF_NOARP; 497 dev->features = NETIF_F_HW_CSUM; 498} 499 500struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 501{ 502 struct sk_buff *skb; 503 504 skb = netdev_alloc_skb(dev, sizeof(struct can_frame)); 505 if (unlikely(!skb)) 506 return NULL; 507 508 skb->protocol = htons(ETH_P_CAN); 509 skb->pkt_type = PACKET_BROADCAST; 510 skb->ip_summed = CHECKSUM_UNNECESSARY; 511 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 512 memset(*cf, 0, sizeof(struct can_frame)); 513 514 return skb; 515} 516EXPORT_SYMBOL_GPL(alloc_can_skb); 517 518struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 519{ 520 struct sk_buff *skb; 521 522 skb = alloc_can_skb(dev, cf); 523 if (unlikely(!skb)) 524 return NULL; 525 526 (*cf)->can_id = CAN_ERR_FLAG; 527 (*cf)->can_dlc = CAN_ERR_DLC; 528 529 return skb; 530} 531EXPORT_SYMBOL_GPL(alloc_can_err_skb); 532 533/* 534 * Allocate and setup space for the CAN network device 535 */ 536struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 537{ 538 struct net_device *dev; 539 struct can_priv *priv; 540 int size; 541 542 if (echo_skb_max) 543 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 544 echo_skb_max * sizeof(struct sk_buff *); 545 else 546 size = sizeof_priv; 547 548 dev = alloc_netdev(size, "can%d", can_setup); 549 if (!dev) 550 return NULL; 551 552 priv = netdev_priv(dev); 553 554 if (echo_skb_max) { 555 priv->echo_skb_max = echo_skb_max; 556 priv->echo_skb = (void *)priv + 557 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 558 } 559 560 priv->state = CAN_STATE_STOPPED; 561 562 init_timer(&priv->restart_timer); 563 564 return dev; 565} 566EXPORT_SYMBOL_GPL(alloc_candev); 567 568/* 569 * Free space of the CAN network device 570 */ 571void free_candev(struct net_device *dev) 572{ 573 free_netdev(dev); 574} 575EXPORT_SYMBOL_GPL(free_candev); 576 577/* 578 * Common open function when the device gets opened. 579 * 580 * This function should be called in the open function of the device 581 * driver. 582 */ 583int open_candev(struct net_device *dev) 584{ 585 struct can_priv *priv = netdev_priv(dev); 586 587 if (!priv->bittiming.tq && !priv->bittiming.bitrate) { 588 netdev_err(dev, "bit-timing not yet defined\n"); 589 return -EINVAL; 590 } 591 592 /* Switch carrier on if device was stopped while in bus-off state */ 593 if (!netif_carrier_ok(dev)) 594 netif_carrier_on(dev); 595 596 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 597 598 return 0; 599} 600EXPORT_SYMBOL_GPL(open_candev); 601 602/* 603 * Common close function for cleanup before the device gets closed. 604 * 605 * This function should be called in the close function of the device 606 * driver. 607 */ 608void close_candev(struct net_device *dev) 609{ 610 struct can_priv *priv = netdev_priv(dev); 611 612 if (del_timer_sync(&priv->restart_timer)) 613 dev_put(dev); 614 can_flush_echo_skb(dev); 615} 616EXPORT_SYMBOL_GPL(close_candev); 617 618/* 619 * CAN netlink interface 620 */ 621static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 622 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 623 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 624 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 625 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 626 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 627 [IFLA_CAN_BITTIMING_CONST] 628 = { .len = sizeof(struct can_bittiming_const) }, 629 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 630 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 631}; 632 633static int can_changelink(struct net_device *dev, 634 struct nlattr *tb[], struct nlattr *data[]) 635{ 636 struct can_priv *priv = netdev_priv(dev); 637 int err; 638 639 /* We need synchronization with dev->stop() */ 640 ASSERT_RTNL(); 641 642 if (data[IFLA_CAN_CTRLMODE]) { 643 struct can_ctrlmode *cm; 644 645 /* Do not allow changing controller mode while running */ 646 if (dev->flags & IFF_UP) 647 return -EBUSY; 648 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 649 if (cm->flags & ~priv->ctrlmode_supported) 650 return -EOPNOTSUPP; 651 priv->ctrlmode &= ~cm->mask; 652 priv->ctrlmode |= cm->flags; 653 } 654 655 if (data[IFLA_CAN_BITTIMING]) { 656 struct can_bittiming bt; 657 658 /* Do not allow changing bittiming while running */ 659 if (dev->flags & IFF_UP) 660 return -EBUSY; 661 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 662 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq)) 663 return -EINVAL; 664 err = can_get_bittiming(dev, &bt); 665 if (err) 666 return err; 667 memcpy(&priv->bittiming, &bt, sizeof(bt)); 668 669 if (priv->do_set_bittiming) { 670 /* Finally, set the bit-timing registers */ 671 err = priv->do_set_bittiming(dev); 672 if (err) 673 return err; 674 } 675 } 676 677 if (data[IFLA_CAN_RESTART_MS]) { 678 /* Do not allow changing restart delay while running */ 679 if (dev->flags & IFF_UP) 680 return -EBUSY; 681 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 682 } 683 684 if (data[IFLA_CAN_RESTART]) { 685 /* Do not allow a restart while not running */ 686 if (!(dev->flags & IFF_UP)) 687 return -EINVAL; 688 err = can_restart_now(dev); 689 if (err) 690 return err; 691 } 692 693 return 0; 694} 695 696static size_t can_get_size(const struct net_device *dev) 697{ 698 struct can_priv *priv = netdev_priv(dev); 699 size_t size; 700 701 size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 702 size += sizeof(struct can_ctrlmode); /* IFLA_CAN_CTRLMODE */ 703 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 704 size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */ 705 size += sizeof(struct can_clock); /* IFLA_CAN_CLOCK */ 706 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 707 size += sizeof(struct can_berr_counter); 708 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 709 size += sizeof(struct can_bittiming_const); 710 711 return size; 712} 713 714static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 715{ 716 struct can_priv *priv = netdev_priv(dev); 717 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 718 struct can_berr_counter bec; 719 enum can_state state = priv->state; 720 721 if (priv->do_get_state) 722 priv->do_get_state(dev, &state); 723 if (nla_put_u32(skb, IFLA_CAN_STATE, state) || 724 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 725 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 726 nla_put(skb, IFLA_CAN_BITTIMING, 727 sizeof(priv->bittiming), &priv->bittiming) || 728 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) || 729 (priv->do_get_berr_counter && 730 !priv->do_get_berr_counter(dev, &bec) && 731 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || 732 (priv->bittiming_const && 733 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 734 sizeof(*priv->bittiming_const), priv->bittiming_const))) 735 goto nla_put_failure; 736 return 0; 737 738nla_put_failure: 739 return -EMSGSIZE; 740} 741 742static size_t can_get_xstats_size(const struct net_device *dev) 743{ 744 return sizeof(struct can_device_stats); 745} 746 747static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 748{ 749 struct can_priv *priv = netdev_priv(dev); 750 751 if (nla_put(skb, IFLA_INFO_XSTATS, 752 sizeof(priv->can_stats), &priv->can_stats)) 753 goto nla_put_failure; 754 return 0; 755 756nla_put_failure: 757 return -EMSGSIZE; 758} 759 760static int can_newlink(struct net *src_net, struct net_device *dev, 761 struct nlattr *tb[], struct nlattr *data[]) 762{ 763 return -EOPNOTSUPP; 764} 765 766static struct rtnl_link_ops can_link_ops __read_mostly = { 767 .kind = "can", 768 .maxtype = IFLA_CAN_MAX, 769 .policy = can_policy, 770 .setup = can_setup, 771 .newlink = can_newlink, 772 .changelink = can_changelink, 773 .get_size = can_get_size, 774 .fill_info = can_fill_info, 775 .get_xstats_size = can_get_xstats_size, 776 .fill_xstats = can_fill_xstats, 777}; 778 779/* 780 * Register the CAN network device 781 */ 782int register_candev(struct net_device *dev) 783{ 784 dev->rtnl_link_ops = &can_link_ops; 785 return register_netdev(dev); 786} 787EXPORT_SYMBOL_GPL(register_candev); 788 789/* 790 * Unregister the CAN network device 791 */ 792void unregister_candev(struct net_device *dev) 793{ 794 unregister_netdev(dev); 795} 796EXPORT_SYMBOL_GPL(unregister_candev); 797 798static __init int can_dev_init(void) 799{ 800 int err; 801 802 err = rtnl_link_register(&can_link_ops); 803 if (!err) 804 printk(KERN_INFO MOD_DESC "\n"); 805 806 return err; 807} 808module_init(can_dev_init); 809 810static __exit void can_dev_exit(void) 811{ 812 rtnl_link_unregister(&can_link_ops); 813} 814module_exit(can_dev_exit); 815 816MODULE_ALIAS_RTNL_LINK("can"); 817