ip: fix error queue empty skb handling
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / drivers / net / can / dev.c
CommitLineData
39549eef
WG
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
05780d98 16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
39549eef
WG
17 */
18
19#include <linux/module.h>
20#include <linux/kernel.h>
5a0e3ad6 21#include <linux/slab.h>
39549eef
WG
22#include <linux/netdevice.h>
23#include <linux/if_arp.h>
24#include <linux/can.h>
25#include <linux/can/dev.h>
156c2bb9 26#include <linux/can/skb.h>
39549eef 27#include <linux/can/netlink.h>
a1ef7bd9 28#include <linux/can/led.h>
39549eef
WG
29#include <net/rtnetlink.h>
30
31#define MOD_DESC "CAN device driver interface"
32
33MODULE_DESCRIPTION(MOD_DESC);
34MODULE_LICENSE("GPL v2");
35MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
36
1e0625fa
OH
37/* CAN DLC to real data length conversion helpers */
38
39static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
40 8, 12, 16, 20, 24, 32, 48, 64};
41
42/* get data length from can_dlc with sanitized can_dlc */
43u8 can_dlc2len(u8 can_dlc)
44{
45 return dlc2len[can_dlc & 0x0F];
46}
47EXPORT_SYMBOL_GPL(can_dlc2len);
48
49static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
50 9, 9, 9, 9, /* 9 - 12 */
51 10, 10, 10, 10, /* 13 - 16 */
52 11, 11, 11, 11, /* 17 - 20 */
53 12, 12, 12, 12, /* 21 - 24 */
54 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
55 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
56 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
57 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
58 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
59
60/* map the sanitized data length to an appropriate data length code */
61u8 can_len2dlc(u8 len)
62{
63 if (unlikely(len > 64))
64 return 0xF;
65
66 return len2dlc[len];
67}
68EXPORT_SYMBOL_GPL(can_len2dlc);
69
39549eef
WG
70#ifdef CONFIG_CAN_CALC_BITTIMING
71#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
72
73/*
74 * Bit-timing calculation derived from:
75 *
76 * Code based on LinCAN sources and H8S2638 project
77 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
78 * Copyright 2005 Stanislav Marek
79 * email: pisa@cmp.felk.cvut.cz
80 *
81 * Calculates proper bit-timing parameters for a specified bit-rate
82 * and sample-point, which can then be used to set the bit-timing
83 * registers of the CAN controller. You can find more information
84 * in the header file linux/can/netlink.h.
85 */
86static int can_update_spt(const struct can_bittiming_const *btc,
87 int sampl_pt, int tseg, int *tseg1, int *tseg2)
88{
89 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
90 if (*tseg2 < btc->tseg2_min)
91 *tseg2 = btc->tseg2_min;
92 if (*tseg2 > btc->tseg2_max)
93 *tseg2 = btc->tseg2_max;
94 *tseg1 = tseg - *tseg2;
95 if (*tseg1 > btc->tseg1_max) {
96 *tseg1 = btc->tseg1_max;
97 *tseg2 = tseg - *tseg1;
98 }
99 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
100}
101
08da7da4
OH
102static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
103 const struct can_bittiming_const *btc)
39549eef
WG
104{
105 struct can_priv *priv = netdev_priv(dev);
39549eef
WG
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;
b25a4372 110 long rate;
39549eef
WG
111 u64 v64;
112
67b5909e 113 /* Use CiA recommended sample points */
39549eef
WG
114 if (bt->sample_point) {
115 sampl_pt = bt->sample_point;
116 } else {
117 if (bt->bitrate > 800000)
118 sampl_pt = 750;
119 else if (bt->bitrate > 500000)
120 sampl_pt = 800;
121 else
122 sampl_pt = 875;
123 }
124
125 /* tseg even = round down, odd = round up */
126 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
127 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
128 tsegall = 1 + tseg / 2;
129 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
130 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
131 /* chose brp step which is possible in system */
132 brp = (brp / btc->brp_inc) * btc->brp_inc;
133 if ((brp < btc->brp_min) || (brp > btc->brp_max))
134 continue;
135 rate = priv->clock.freq / (brp * tsegall);
136 error = bt->bitrate - rate;
137 /* tseg brp biterror */
138 if (error < 0)
139 error = -error;
140 if (error > best_error)
141 continue;
142 best_error = error;
143 if (error == 0) {
144 spt = can_update_spt(btc, sampl_pt, tseg / 2,
145 &tseg1, &tseg2);
146 error = sampl_pt - spt;
147 if (error < 0)
148 error = -error;
149 if (error > spt_error)
150 continue;
151 spt_error = error;
152 }
153 best_tseg = tseg / 2;
154 best_brp = brp;
39549eef
WG
155 if (error == 0)
156 break;
157 }
158
159 if (best_error) {
160 /* Error in one-tenth of a percent */
161 error = (best_error * 1000) / bt->bitrate;
162 if (error > CAN_CALC_MAX_ERROR) {
aabdfd6a
WG
163 netdev_err(dev,
164 "bitrate error %ld.%ld%% too high\n",
165 error / 10, error % 10);
39549eef
WG
166 return -EDOM;
167 } else {
aabdfd6a
WG
168 netdev_warn(dev, "bitrate error %ld.%ld%%\n",
169 error / 10, error % 10);
39549eef
WG
170 }
171 }
172
173 /* real sample point */
174 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
175 &tseg1, &tseg2);
176
177 v64 = (u64)best_brp * 1000000000UL;
178 do_div(v64, priv->clock.freq);
179 bt->tq = (u32)v64;
180 bt->prop_seg = tseg1 / 2;
181 bt->phase_seg1 = tseg1 - bt->prop_seg;
182 bt->phase_seg2 = tseg2;
2e114374
OH
183
184 /* check for sjw user settings */
185 if (!bt->sjw || !btc->sjw_max)
186 bt->sjw = 1;
187 else {
188 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
189 if (bt->sjw > btc->sjw_max)
190 bt->sjw = btc->sjw_max;
191 /* bt->sjw must not be higher than tseg2 */
192 if (tseg2 < bt->sjw)
193 bt->sjw = tseg2;
194 }
195
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WG
196 bt->brp = best_brp;
197 /* real bit-rate */
198 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
199
200 return 0;
201}
202#else /* !CONFIG_CAN_CALC_BITTIMING */
08da7da4
OH
203static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
204 const struct can_bittiming_const *btc)
39549eef 205{
aabdfd6a 206 netdev_err(dev, "bit-timing calculation not available\n");
39549eef
WG
207 return -EINVAL;
208}
209#endif /* CONFIG_CAN_CALC_BITTIMING */
210
211/*
212 * Checks the validity of the specified bit-timing parameters prop_seg,
213 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
214 * prescaler value brp. You can find more information in the header
215 * file linux/can/netlink.h.
216 */
08da7da4
OH
217static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
218 const struct can_bittiming_const *btc)
39549eef
WG
219{
220 struct can_priv *priv = netdev_priv(dev);
39549eef
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221 int tseg1, alltseg;
222 u64 brp64;
223
39549eef
WG
224 tseg1 = bt->prop_seg + bt->phase_seg1;
225 if (!bt->sjw)
226 bt->sjw = 1;
227 if (bt->sjw > btc->sjw_max ||
228 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
229 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
230 return -ERANGE;
231
232 brp64 = (u64)priv->clock.freq * (u64)bt->tq;
233 if (btc->brp_inc > 1)
234 do_div(brp64, btc->brp_inc);
235 brp64 += 500000000UL - 1;
236 do_div(brp64, 1000000000UL); /* the practicable BRP */
237 if (btc->brp_inc > 1)
238 brp64 *= btc->brp_inc;
239 bt->brp = (u32)brp64;
240
241 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
242 return -EINVAL;
243
244 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
245 bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
246 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
247
248 return 0;
249}
250
08da7da4
OH
251static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
252 const struct can_bittiming_const *btc)
39549eef 253{
39549eef
WG
254 int err;
255
256 /* Check if the CAN device has bit-timing parameters */
08da7da4 257 if (!btc)
d4824432 258 return -EOPNOTSUPP;
39549eef 259
d5298dff
OH
260 /*
261 * Depending on the given can_bittiming parameter structure the CAN
262 * timing parameters are calculated based on the provided bitrate OR
263 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
264 * provided directly which are then checked and fixed up.
265 */
266 if (!bt->tq && bt->bitrate)
08da7da4 267 err = can_calc_bittiming(dev, bt, btc);
d5298dff 268 else if (bt->tq && !bt->bitrate)
08da7da4 269 err = can_fixup_bittiming(dev, bt, btc);
d5298dff
OH
270 else
271 err = -EINVAL;
39549eef 272
d5298dff 273 return err;
39549eef
WG
274}
275
bac78aab
AY
276static void can_update_state_error_stats(struct net_device *dev,
277 enum can_state new_state)
278{
279 struct can_priv *priv = netdev_priv(dev);
280
281 if (new_state <= priv->state)
282 return;
283
284 switch (new_state) {
285 case CAN_STATE_ERROR_WARNING:
286 priv->can_stats.error_warning++;
287 break;
288 case CAN_STATE_ERROR_PASSIVE:
289 priv->can_stats.error_passive++;
290 break;
291 case CAN_STATE_BUS_OFF:
be38a6f9
AY
292 priv->can_stats.bus_off++;
293 break;
bac78aab
AY
294 default:
295 break;
5b5ba2af 296 }
bac78aab
AY
297}
298
299static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
300{
301 switch (state) {
302 case CAN_STATE_ERROR_ACTIVE:
303 return CAN_ERR_CRTL_ACTIVE;
304 case CAN_STATE_ERROR_WARNING:
305 return CAN_ERR_CRTL_TX_WARNING;
306 case CAN_STATE_ERROR_PASSIVE:
307 return CAN_ERR_CRTL_TX_PASSIVE;
308 default:
309 return 0;
310 }
311}
312
313static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
314{
315 switch (state) {
316 case CAN_STATE_ERROR_ACTIVE:
317 return CAN_ERR_CRTL_ACTIVE;
318 case CAN_STATE_ERROR_WARNING:
319 return CAN_ERR_CRTL_RX_WARNING;
320 case CAN_STATE_ERROR_PASSIVE:
321 return CAN_ERR_CRTL_RX_PASSIVE;
322 default:
323 return 0;
324 }
325}
326
327void can_change_state(struct net_device *dev, struct can_frame *cf,
328 enum can_state tx_state, enum can_state rx_state)
329{
330 struct can_priv *priv = netdev_priv(dev);
331 enum can_state new_state = max(tx_state, rx_state);
332
333 if (unlikely(new_state == priv->state)) {
334 netdev_warn(dev, "%s: oops, state did not change", __func__);
335 return;
336 }
337
338 netdev_dbg(dev, "New error state: %d\n", new_state);
339
340 can_update_state_error_stats(dev, new_state);
341 priv->state = new_state;
342
343 if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
344 cf->can_id |= CAN_ERR_BUSOFF;
345 return;
346 }
347
348 cf->can_id |= CAN_ERR_CRTL;
349 cf->data[1] |= tx_state >= rx_state ?
350 can_tx_state_to_frame(dev, tx_state) : 0;
351 cf->data[1] |= tx_state <= rx_state ?
352 can_rx_state_to_frame(dev, rx_state) : 0;
353}
354EXPORT_SYMBOL_GPL(can_change_state);
355
39549eef
WG
356/*
357 * Local echo of CAN messages
358 *
359 * CAN network devices *should* support a local echo functionality
360 * (see Documentation/networking/can.txt). To test the handling of CAN
361 * interfaces that do not support the local echo both driver types are
362 * implemented. In the case that the driver does not support the echo
363 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
364 * to perform the echo as a fallback solution.
365 */
366static void can_flush_echo_skb(struct net_device *dev)
367{
368 struct can_priv *priv = netdev_priv(dev);
369 struct net_device_stats *stats = &dev->stats;
370 int i;
371
a6e4bc53 372 for (i = 0; i < priv->echo_skb_max; i++) {
39549eef
WG
373 if (priv->echo_skb[i]) {
374 kfree_skb(priv->echo_skb[i]);
375 priv->echo_skb[i] = NULL;
376 stats->tx_dropped++;
377 stats->tx_aborted_errors++;
378 }
379 }
380}
381
382/*
383 * Put the skb on the stack to be looped backed locally lateron
384 *
385 * The function is typically called in the start_xmit function
386 * of the device driver. The driver must protect access to
387 * priv->echo_skb, if necessary.
388 */
a6e4bc53
WG
389void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
390 unsigned int idx)
39549eef
WG
391{
392 struct can_priv *priv = netdev_priv(dev);
393
a6e4bc53
WG
394 BUG_ON(idx >= priv->echo_skb_max);
395
39549eef 396 /* check flag whether this packet has to be looped back */
a94bc9c4
OH
397 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
398 (skb->protocol != htons(ETH_P_CAN) &&
399 skb->protocol != htons(ETH_P_CANFD))) {
39549eef
WG
400 kfree_skb(skb);
401 return;
402 }
403
404 if (!priv->echo_skb[idx]) {
39549eef 405
0ae89beb
OH
406 skb = can_create_echo_skb(skb);
407 if (!skb)
408 return;
39549eef
WG
409
410 /* make settings for echo to reduce code in irq context */
39549eef
WG
411 skb->pkt_type = PACKET_BROADCAST;
412 skb->ip_summed = CHECKSUM_UNNECESSARY;
413 skb->dev = dev;
414
415 /* save this skb for tx interrupt echo handling */
416 priv->echo_skb[idx] = skb;
417 } else {
418 /* locking problem with netif_stop_queue() ?? */
aabdfd6a 419 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
39549eef
WG
420 kfree_skb(skb);
421 }
422}
423EXPORT_SYMBOL_GPL(can_put_echo_skb);
424
425/*
426 * Get the skb from the stack and loop it back locally
427 *
428 * The function is typically called when the TX done interrupt
429 * is handled in the device driver. The driver must protect
430 * access to priv->echo_skb, if necessary.
431 */
cf5046b3 432unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
39549eef
WG
433{
434 struct can_priv *priv = netdev_priv(dev);
435
a6e4bc53
WG
436 BUG_ON(idx >= priv->echo_skb_max);
437
39e3ab6f 438 if (priv->echo_skb[idx]) {
cf5046b3
MKB
439 struct sk_buff *skb = priv->echo_skb[idx];
440 struct can_frame *cf = (struct can_frame *)skb->data;
441 u8 dlc = cf->can_dlc;
442
39549eef
WG
443 netif_rx(priv->echo_skb[idx]);
444 priv->echo_skb[idx] = NULL;
cf5046b3
MKB
445
446 return dlc;
39549eef 447 }
cf5046b3
MKB
448
449 return 0;
39549eef
WG
450}
451EXPORT_SYMBOL_GPL(can_get_echo_skb);
452
39e3ab6f
WG
453/*
454 * Remove the skb from the stack and free it.
455 *
456 * The function is typically called when TX failed.
457 */
a6e4bc53 458void can_free_echo_skb(struct net_device *dev, unsigned int idx)
39e3ab6f
WG
459{
460 struct can_priv *priv = netdev_priv(dev);
461
a6e4bc53
WG
462 BUG_ON(idx >= priv->echo_skb_max);
463
39e3ab6f 464 if (priv->echo_skb[idx]) {
5247a589 465 dev_kfree_skb_any(priv->echo_skb[idx]);
39e3ab6f
WG
466 priv->echo_skb[idx] = NULL;
467 }
468}
469EXPORT_SYMBOL_GPL(can_free_echo_skb);
470
39549eef
WG
471/*
472 * CAN device restart for bus-off recovery
473 */
77fc95a3 474static void can_restart(unsigned long data)
39549eef
WG
475{
476 struct net_device *dev = (struct net_device *)data;
477 struct can_priv *priv = netdev_priv(dev);
478 struct net_device_stats *stats = &dev->stats;
479 struct sk_buff *skb;
480 struct can_frame *cf;
481 int err;
482
483 BUG_ON(netif_carrier_ok(dev));
484
485 /*
486 * No synchronization needed because the device is bus-off and
487 * no messages can come in or go out.
488 */
489 can_flush_echo_skb(dev);
490
491 /* send restart message upstream */
7b6856a0 492 skb = alloc_can_err_skb(dev, &cf);
39549eef
WG
493 if (skb == NULL) {
494 err = -ENOMEM;
b3d0df7c 495 goto restart;
39549eef 496 }
7b6856a0 497 cf->can_id |= CAN_ERR_RESTARTED;
39549eef
WG
498
499 netif_rx(skb);
500
39549eef
WG
501 stats->rx_packets++;
502 stats->rx_bytes += cf->can_dlc;
503
b3d0df7c 504restart:
aabdfd6a 505 netdev_dbg(dev, "restarted\n");
39549eef
WG
506 priv->can_stats.restarts++;
507
508 /* Now restart the device */
509 err = priv->do_set_mode(dev, CAN_MODE_START);
510
39549eef
WG
511 netif_carrier_on(dev);
512 if (err)
aabdfd6a 513 netdev_err(dev, "Error %d during restart", err);
39549eef
WG
514}
515
516int can_restart_now(struct net_device *dev)
517{
518 struct can_priv *priv = netdev_priv(dev);
519
520 /*
521 * A manual restart is only permitted if automatic restart is
522 * disabled and the device is in the bus-off state
523 */
524 if (priv->restart_ms)
525 return -EINVAL;
526 if (priv->state != CAN_STATE_BUS_OFF)
527 return -EBUSY;
528
529 /* Runs as soon as possible in the timer context */
530 mod_timer(&priv->restart_timer, jiffies);
531
532 return 0;
533}
534
535/*
536 * CAN bus-off
537 *
538 * This functions should be called when the device goes bus-off to
539 * tell the netif layer that no more packets can be sent or received.
540 * If enabled, a timer is started to trigger bus-off recovery.
541 */
542void can_bus_off(struct net_device *dev)
543{
544 struct can_priv *priv = netdev_priv(dev);
545
aabdfd6a 546 netdev_dbg(dev, "bus-off\n");
39549eef
WG
547
548 netif_carrier_off(dev);
39549eef
WG
549
550 if (priv->restart_ms)
551 mod_timer(&priv->restart_timer,
552 jiffies + (priv->restart_ms * HZ) / 1000);
553}
554EXPORT_SYMBOL_GPL(can_bus_off);
555
556static void can_setup(struct net_device *dev)
557{
558 dev->type = ARPHRD_CAN;
1e0625fa 559 dev->mtu = CAN_MTU;
39549eef
WG
560 dev->hard_header_len = 0;
561 dev->addr_len = 0;
562 dev->tx_queue_len = 10;
563
564 /* New-style flags. */
565 dev->flags = IFF_NOARP;
34324dc2 566 dev->features = NETIF_F_HW_CSUM;
39549eef
WG
567}
568
7b6856a0
WG
569struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
570{
571 struct sk_buff *skb;
572
156c2bb9
OH
573 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
574 sizeof(struct can_frame));
7b6856a0
WG
575 if (unlikely(!skb))
576 return NULL;
577
578 skb->protocol = htons(ETH_P_CAN);
579 skb->pkt_type = PACKET_BROADCAST;
580 skb->ip_summed = CHECKSUM_UNNECESSARY;
156c2bb9 581
2bf3440d
OH
582 can_skb_reserve(skb);
583 can_skb_prv(skb)->ifindex = dev->ifindex;
156c2bb9 584
7b6856a0
WG
585 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
586 memset(*cf, 0, sizeof(struct can_frame));
587
588 return skb;
589}
590EXPORT_SYMBOL_GPL(alloc_can_skb);
591
cb2518ca
SG
592struct sk_buff *alloc_canfd_skb(struct net_device *dev,
593 struct canfd_frame **cfd)
594{
595 struct sk_buff *skb;
596
597 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
598 sizeof(struct canfd_frame));
599 if (unlikely(!skb))
600 return NULL;
601
602 skb->protocol = htons(ETH_P_CANFD);
603 skb->pkt_type = PACKET_BROADCAST;
604 skb->ip_summed = CHECKSUM_UNNECESSARY;
605
606 can_skb_reserve(skb);
607 can_skb_prv(skb)->ifindex = dev->ifindex;
608
609 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame));
610 memset(*cfd, 0, sizeof(struct canfd_frame));
611
612 return skb;
613}
614EXPORT_SYMBOL_GPL(alloc_canfd_skb);
615
7b6856a0
WG
616struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
617{
618 struct sk_buff *skb;
619
620 skb = alloc_can_skb(dev, cf);
621 if (unlikely(!skb))
622 return NULL;
623
624 (*cf)->can_id = CAN_ERR_FLAG;
625 (*cf)->can_dlc = CAN_ERR_DLC;
626
627 return skb;
628}
629EXPORT_SYMBOL_GPL(alloc_can_err_skb);
630
39549eef
WG
631/*
632 * Allocate and setup space for the CAN network device
633 */
a6e4bc53 634struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
39549eef
WG
635{
636 struct net_device *dev;
637 struct can_priv *priv;
a6e4bc53 638 int size;
39549eef 639
a6e4bc53
WG
640 if (echo_skb_max)
641 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
642 echo_skb_max * sizeof(struct sk_buff *);
643 else
644 size = sizeof_priv;
645
c835a677 646 dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
39549eef
WG
647 if (!dev)
648 return NULL;
649
650 priv = netdev_priv(dev);
651
a6e4bc53
WG
652 if (echo_skb_max) {
653 priv->echo_skb_max = echo_skb_max;
654 priv->echo_skb = (void *)priv +
655 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
656 }
657
39549eef
WG
658 priv->state = CAN_STATE_STOPPED;
659
660 init_timer(&priv->restart_timer);
661
662 return dev;
663}
664EXPORT_SYMBOL_GPL(alloc_candev);
665
666/*
667 * Free space of the CAN network device
668 */
669void free_candev(struct net_device *dev)
670{
671 free_netdev(dev);
672}
673EXPORT_SYMBOL_GPL(free_candev);
674
bc05a894
OH
675/*
676 * changing MTU and control mode for CAN/CANFD devices
677 */
678int can_change_mtu(struct net_device *dev, int new_mtu)
679{
680 struct can_priv *priv = netdev_priv(dev);
681
682 /* Do not allow changing the MTU while running */
683 if (dev->flags & IFF_UP)
684 return -EBUSY;
685
686 /* allow change of MTU according to the CANFD ability of the device */
687 switch (new_mtu) {
688 case CAN_MTU:
689 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
690 break;
691
692 case CANFD_MTU:
693 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD))
694 return -EINVAL;
695
696 priv->ctrlmode |= CAN_CTRLMODE_FD;
697 break;
698
699 default:
700 return -EINVAL;
701 }
702
703 dev->mtu = new_mtu;
704 return 0;
705}
706EXPORT_SYMBOL_GPL(can_change_mtu);
707
39549eef
WG
708/*
709 * Common open function when the device gets opened.
710 *
711 * This function should be called in the open function of the device
712 * driver.
713 */
714int open_candev(struct net_device *dev)
715{
716 struct can_priv *priv = netdev_priv(dev);
717
b30749fd 718 if (!priv->bittiming.bitrate) {
aabdfd6a 719 netdev_err(dev, "bit-timing not yet defined\n");
39549eef
WG
720 return -EINVAL;
721 }
722
dd22586d
OH
723 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
724 if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
725 (!priv->data_bittiming.bitrate ||
726 (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
727 netdev_err(dev, "incorrect/missing data bit-timing\n");
728 return -EINVAL;
729 }
730
1b0d9224
WG
731 /* Switch carrier on if device was stopped while in bus-off state */
732 if (!netif_carrier_ok(dev))
733 netif_carrier_on(dev);
734
39549eef
WG
735 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
736
737 return 0;
738}
128ced8f 739EXPORT_SYMBOL_GPL(open_candev);
39549eef
WG
740
741/*
742 * Common close function for cleanup before the device gets closed.
743 *
744 * This function should be called in the close function of the device
745 * driver.
746 */
747void close_candev(struct net_device *dev)
748{
749 struct can_priv *priv = netdev_priv(dev);
750
ab48b03e 751 del_timer_sync(&priv->restart_timer);
39549eef
WG
752 can_flush_echo_skb(dev);
753}
754EXPORT_SYMBOL_GPL(close_candev);
755
756/*
757 * CAN netlink interface
758 */
759static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
760 [IFLA_CAN_STATE] = { .type = NLA_U32 },
761 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
762 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
763 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
764 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
765 [IFLA_CAN_BITTIMING_CONST]
766 = { .len = sizeof(struct can_bittiming_const) },
767 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
52c793f2 768 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
9859ccd2
OH
769 [IFLA_CAN_DATA_BITTIMING]
770 = { .len = sizeof(struct can_bittiming) },
771 [IFLA_CAN_DATA_BITTIMING_CONST]
772 = { .len = sizeof(struct can_bittiming_const) },
39549eef
WG
773};
774
775static int can_changelink(struct net_device *dev,
776 struct nlattr *tb[], struct nlattr *data[])
777{
778 struct can_priv *priv = netdev_priv(dev);
779 int err;
780
781 /* We need synchronization with dev->stop() */
782 ASSERT_RTNL();
783
39549eef
WG
784 if (data[IFLA_CAN_BITTIMING]) {
785 struct can_bittiming bt;
786
787 /* Do not allow changing bittiming while running */
788 if (dev->flags & IFF_UP)
789 return -EBUSY;
790 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
08da7da4 791 err = can_get_bittiming(dev, &bt, priv->bittiming_const);
39549eef
WG
792 if (err)
793 return err;
794 memcpy(&priv->bittiming, &bt, sizeof(bt));
795
796 if (priv->do_set_bittiming) {
797 /* Finally, set the bit-timing registers */
798 err = priv->do_set_bittiming(dev);
799 if (err)
800 return err;
801 }
802 }
803
49cb5c0e
MKB
804 if (data[IFLA_CAN_CTRLMODE]) {
805 struct can_ctrlmode *cm;
806
807 /* Do not allow changing controller mode while running */
808 if (dev->flags & IFF_UP)
809 return -EBUSY;
810 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
9b1087aa
OH
811
812 /* check whether changed bits are allowed to be modified */
813 if (cm->mask & ~priv->ctrlmode_supported)
49cb5c0e 814 return -EOPNOTSUPP;
9b1087aa
OH
815
816 /* clear bits to be modified and copy the flag values */
49cb5c0e 817 priv->ctrlmode &= ~cm->mask;
9b1087aa 818 priv->ctrlmode |= (cm->flags & cm->mask);
bc05a894
OH
819
820 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
821 if (priv->ctrlmode & CAN_CTRLMODE_FD)
822 dev->mtu = CANFD_MTU;
823 else
824 dev->mtu = CAN_MTU;
49cb5c0e
MKB
825 }
826
39549eef
WG
827 if (data[IFLA_CAN_RESTART_MS]) {
828 /* Do not allow changing restart delay while running */
829 if (dev->flags & IFF_UP)
830 return -EBUSY;
831 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
832 }
833
834 if (data[IFLA_CAN_RESTART]) {
835 /* Do not allow a restart while not running */
836 if (!(dev->flags & IFF_UP))
837 return -EINVAL;
838 err = can_restart_now(dev);
839 if (err)
840 return err;
841 }
842
9859ccd2
OH
843 if (data[IFLA_CAN_DATA_BITTIMING]) {
844 struct can_bittiming dbt;
845
846 /* Do not allow changing bittiming while running */
847 if (dev->flags & IFF_UP)
848 return -EBUSY;
849 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
850 sizeof(dbt));
851 err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const);
852 if (err)
853 return err;
854 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
855
856 if (priv->do_set_data_bittiming) {
857 /* Finally, set the bit-timing registers */
858 err = priv->do_set_data_bittiming(dev);
859 if (err)
860 return err;
861 }
862 }
863
39549eef
WG
864 return 0;
865}
866
53a0ef86
WG
867static size_t can_get_size(const struct net_device *dev)
868{
869 struct can_priv *priv = netdev_priv(dev);
c13c64d8
MKB
870 size_t size = 0;
871
b30749fd
OH
872 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
873 size += nla_total_size(sizeof(struct can_bittiming));
c13c64d8 874 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
fe119a05 875 size += nla_total_size(sizeof(struct can_bittiming_const));
c13c64d8
MKB
876 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
877 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
878 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
879 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
880 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
881 size += nla_total_size(sizeof(struct can_berr_counter));
9859ccd2
OH
882 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
883 size += nla_total_size(sizeof(struct can_bittiming));
884 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
885 size += nla_total_size(sizeof(struct can_bittiming_const));
53a0ef86
WG
886
887 return size;
888}
889
39549eef
WG
890static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
891{
892 struct can_priv *priv = netdev_priv(dev);
893 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
52c793f2 894 struct can_berr_counter bec;
39549eef
WG
895 enum can_state state = priv->state;
896
897 if (priv->do_get_state)
898 priv->do_get_state(dev, &state);
9859ccd2 899
b30749fd
OH
900 if ((priv->bittiming.bitrate &&
901 nla_put(skb, IFLA_CAN_BITTIMING,
902 sizeof(priv->bittiming), &priv->bittiming)) ||
9859ccd2 903
57a59b9e
MKB
904 (priv->bittiming_const &&
905 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
906 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
9859ccd2 907
31e0e328 908 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
57a59b9e
MKB
909 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
910 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
911 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
9859ccd2 912
31e0e328
DM
913 (priv->do_get_berr_counter &&
914 !priv->do_get_berr_counter(dev, &bec) &&
9859ccd2
OH
915 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
916
917 (priv->data_bittiming.bitrate &&
918 nla_put(skb, IFLA_CAN_DATA_BITTIMING,
919 sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
920
921 (priv->data_bittiming_const &&
922 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
923 sizeof(*priv->data_bittiming_const),
924 priv->data_bittiming_const)))
57a59b9e 925 return -EMSGSIZE;
9859ccd2 926
39549eef 927 return 0;
39549eef
WG
928}
929
55369c0a
WG
930static size_t can_get_xstats_size(const struct net_device *dev)
931{
932 return sizeof(struct can_device_stats);
933}
934
39549eef
WG
935static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
936{
937 struct can_priv *priv = netdev_priv(dev);
938
31e0e328
DM
939 if (nla_put(skb, IFLA_INFO_XSTATS,
940 sizeof(priv->can_stats), &priv->can_stats))
941 goto nla_put_failure;
39549eef
WG
942 return 0;
943
944nla_put_failure:
945 return -EMSGSIZE;
946}
947
81adee47 948static int can_newlink(struct net *src_net, struct net_device *dev,
993e6f2f
OH
949 struct nlattr *tb[], struct nlattr *data[])
950{
951 return -EOPNOTSUPP;
952}
953
39549eef
WG
954static struct rtnl_link_ops can_link_ops __read_mostly = {
955 .kind = "can",
956 .maxtype = IFLA_CAN_MAX,
957 .policy = can_policy,
958 .setup = can_setup,
993e6f2f 959 .newlink = can_newlink,
39549eef 960 .changelink = can_changelink,
53a0ef86 961 .get_size = can_get_size,
39549eef 962 .fill_info = can_fill_info,
55369c0a 963 .get_xstats_size = can_get_xstats_size,
39549eef
WG
964 .fill_xstats = can_fill_xstats,
965};
966
967/*
968 * Register the CAN network device
969 */
970int register_candev(struct net_device *dev)
971{
972 dev->rtnl_link_ops = &can_link_ops;
973 return register_netdev(dev);
974}
975EXPORT_SYMBOL_GPL(register_candev);
976
977/*
978 * Unregister the CAN network device
979 */
980void unregister_candev(struct net_device *dev)
981{
982 unregister_netdev(dev);
983}
984EXPORT_SYMBOL_GPL(unregister_candev);
985
bf03a537
KVD
986/*
987 * Test if a network device is a candev based device
988 * and return the can_priv* if so.
989 */
990struct can_priv *safe_candev_priv(struct net_device *dev)
991{
992 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
993 return NULL;
994
995 return netdev_priv(dev);
996}
997EXPORT_SYMBOL_GPL(safe_candev_priv);
998
39549eef
WG
999static __init int can_dev_init(void)
1000{
1001 int err;
1002
a1ef7bd9
KVD
1003 can_led_notifier_init();
1004
39549eef
WG
1005 err = rtnl_link_register(&can_link_ops);
1006 if (!err)
1007 printk(KERN_INFO MOD_DESC "\n");
1008
1009 return err;
1010}
1011module_init(can_dev_init);
1012
1013static __exit void can_dev_exit(void)
1014{
1015 rtnl_link_unregister(&can_link_ops);
a1ef7bd9
KVD
1016
1017 can_led_notifier_exit();
39549eef
WG
1018}
1019module_exit(can_dev_exit);
1020
1021MODULE_ALIAS_RTNL_LINK("can");