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perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / drivers / net / ethernet / ti / cpts.c
blobb96b93c686bf15581b89c05d347a2179ae9883cc
1 /*
2 * TI Common Platform Time Sync
3 *
4 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20 #include <linux/err.h>
21 #include <linux/if.h>
22 #include <linux/hrtimer.h>
23 #include <linux/module.h>
24 #include <linux/net_tstamp.h>
25 #include <linux/ptp_classify.h>
26 #include <linux/time.h>
27 #include <linux/uaccess.h>
28 #include <linux/workqueue.h>
29 #include <linux/if_ether.h>
30 #include <linux/if_vlan.h>
31
32 #include "cpts.h"
33
34 #define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */
35
36 struct cpts_skb_cb_data {
37 unsigned long tmo;
38 };
39
40 #define cpts_read32(c, r) readl_relaxed(&c->reg->r)
41 #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r)
42
43 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
44 u16 ts_seqid, u8 ts_msgtype);
45
46 static int event_expired(struct cpts_event *event)
47 {
48 return time_after(jiffies, event->tmo);
49 }
50
51 static int event_type(struct cpts_event *event)
52 {
53 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
54 }
55
56 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
57 {
58 u32 r = cpts_read32(cpts, intstat_raw);
59
60 if (r & TS_PEND_RAW) {
61 *high = cpts_read32(cpts, event_high);
62 *low = cpts_read32(cpts, event_low);
63 cpts_write32(cpts, EVENT_POP, event_pop);
64 return 0;
65 }
66 return -1;
67 }
68
69 static int cpts_purge_events(struct cpts *cpts)
70 {
71 struct list_head *this, *next;
72 struct cpts_event *event;
73 int removed = 0;
74
75 list_for_each_safe(this, next, &cpts->events) {
76 event = list_entry(this, struct cpts_event, list);
77 if (event_expired(event)) {
78 list_del_init(&event->list);
79 list_add(&event->list, &cpts->pool);
80 ++removed;
81 }
82 }
83
84 if (removed)
85 pr_debug("cpts: event pool cleaned up %d\n", removed);
86 return removed ? 0 : -1;
87 }
88
89 static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event)
90 {
91 struct sk_buff *skb, *tmp;
92 u16 seqid;
93 u8 mtype;
94 bool found = false;
95
96 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
97 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
98
99 /* no need to grab txq.lock as access is always done under cpts->lock */
100 skb_queue_walk_safe(&cpts->txq, skb, tmp) {
101 struct skb_shared_hwtstamps ssh;
102 unsigned int class = ptp_classify_raw(skb);
103 struct cpts_skb_cb_data *skb_cb =
104 (struct cpts_skb_cb_data *)skb->cb;
105
106 if (cpts_match(skb, class, seqid, mtype)) {
107 u64 ns = timecounter_cyc2time(&cpts->tc, event->low);
108
109 memset(&ssh, 0, sizeof(ssh));
110 ssh.hwtstamp = ns_to_ktime(ns);
111 skb_tstamp_tx(skb, &ssh);
112 found = true;
113 __skb_unlink(skb, &cpts->txq);
114 dev_consume_skb_any(skb);
115 dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n",
116 mtype, seqid);
117 break;
118 }
119
120 if (time_after(jiffies, skb_cb->tmo)) {
121 /* timeout any expired skbs over 1s */
122 dev_dbg(cpts->dev,
123 "expiring tx timestamp mtype %u seqid %04x\n",
124 mtype, seqid);
125 __skb_unlink(skb, &cpts->txq);
126 dev_consume_skb_any(skb);
127 }
128 }
129
130 return found;
131 }
132
133 /*
134 * Returns zero if matching event type was found.
135 */
136 static int cpts_fifo_read(struct cpts *cpts, int match)
137 {
138 int i, type = -1;
139 u32 hi, lo;
140 struct cpts_event *event;
141
142 for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
143 if (cpts_fifo_pop(cpts, &hi, &lo))
144 break;
145
146 if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) {
147 pr_err("cpts: event pool empty\n");
148 return -1;
149 }
150
151 event = list_first_entry(&cpts->pool, struct cpts_event, list);
152 event->tmo = jiffies + 2;
153 event->high = hi;
154 event->low = lo;
155 type = event_type(event);
156 switch (type) {
157 case CPTS_EV_TX:
158 if (cpts_match_tx_ts(cpts, event)) {
159 /* if the new event matches an existing skb,
160 * then don't queue it
161 */
162 break;
163 }
164 /* fall through */
165 case CPTS_EV_PUSH:
166 case CPTS_EV_RX:
167 list_del_init(&event->list);
168 list_add_tail(&event->list, &cpts->events);
169 break;
170 case CPTS_EV_ROLL:
171 case CPTS_EV_HALF:
172 case CPTS_EV_HW:
173 break;
174 default:
175 pr_err("cpts: unknown event type\n");
176 break;
177 }
178 if (type == match)
179 break;
180 }
181 return type == match ? 0 : -1;
182 }
183
184 static u64 cpts_systim_read(const struct cyclecounter *cc)
185 {
186 u64 val = 0;
187 struct cpts_event *event;
188 struct list_head *this, *next;
189 struct cpts *cpts = container_of(cc, struct cpts, cc);
190
191 cpts_write32(cpts, TS_PUSH, ts_push);
192 if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
193 pr_err("cpts: unable to obtain a time stamp\n");
194
195 list_for_each_safe(this, next, &cpts->events) {
196 event = list_entry(this, struct cpts_event, list);
197 if (event_type(event) == CPTS_EV_PUSH) {
198 list_del_init(&event->list);
199 list_add(&event->list, &cpts->pool);
200 val = event->low;
201 break;
202 }
203 }
204
205 return val;
206 }
207
208 /* PTP clock operations */
209
210 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
211 {
212 u64 adj;
213 u32 diff, mult;
214 int neg_adj = 0;
215 unsigned long flags;
216 struct cpts *cpts = container_of(ptp, struct cpts, info);
217
218 if (ppb < 0) {
219 neg_adj = 1;
220 ppb = -ppb;
221 }
222 mult = cpts->cc_mult;
223 adj = mult;
224 adj *= ppb;
225 diff = div_u64(adj, 1000000000ULL);
226
227 spin_lock_irqsave(&cpts->lock, flags);
228
229 timecounter_read(&cpts->tc);
230
231 cpts->cc.mult = neg_adj ? mult - diff : mult + diff;
232
233 spin_unlock_irqrestore(&cpts->lock, flags);
234
235 return 0;
236 }
237
238 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
239 {
240 unsigned long flags;
241 struct cpts *cpts = container_of(ptp, struct cpts, info);
242
243 spin_lock_irqsave(&cpts->lock, flags);
244 timecounter_adjtime(&cpts->tc, delta);
245 spin_unlock_irqrestore(&cpts->lock, flags);
246
247 return 0;
248 }
249
250 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
251 {
252 u64 ns;
253 unsigned long flags;
254 struct cpts *cpts = container_of(ptp, struct cpts, info);
255
256 spin_lock_irqsave(&cpts->lock, flags);
257 ns = timecounter_read(&cpts->tc);
258 spin_unlock_irqrestore(&cpts->lock, flags);
259
260 *ts = ns_to_timespec64(ns);
261
262 return 0;
263 }
264
265 static int cpts_ptp_settime(struct ptp_clock_info *ptp,
266 const struct timespec64 *ts)
267 {
268 u64 ns;
269 unsigned long flags;
270 struct cpts *cpts = container_of(ptp, struct cpts, info);
271
272 ns = timespec64_to_ns(ts);
273
274 spin_lock_irqsave(&cpts->lock, flags);
275 timecounter_init(&cpts->tc, &cpts->cc, ns);
276 spin_unlock_irqrestore(&cpts->lock, flags);
277
278 return 0;
279 }
280
281 static int cpts_ptp_enable(struct ptp_clock_info *ptp,
282 struct ptp_clock_request *rq, int on)
283 {
284 return -EOPNOTSUPP;
285 }
286
287 static long cpts_overflow_check(struct ptp_clock_info *ptp)
288 {
289 struct cpts *cpts = container_of(ptp, struct cpts, info);
290 unsigned long delay = cpts->ov_check_period;
291 struct timespec64 ts;
292 unsigned long flags;
293
294 spin_lock_irqsave(&cpts->lock, flags);
295 ts = ns_to_timespec64(timecounter_read(&cpts->tc));
296
297 if (!skb_queue_empty(&cpts->txq))
298 delay = CPTS_SKB_TX_WORK_TIMEOUT;
299 spin_unlock_irqrestore(&cpts->lock, flags);
300
301 pr_debug("cpts overflow check at %lld.%09ld\n",
302 (long long)ts.tv_sec, ts.tv_nsec);
303 return (long)delay;
304 }
305
306 static const struct ptp_clock_info cpts_info = {
307 .owner = THIS_MODULE,
308 .name = "CTPS timer",
309 .max_adj = 1000000,
310 .n_ext_ts = 0,
311 .n_pins = 0,
312 .pps = 0,
313 .adjfreq = cpts_ptp_adjfreq,
314 .adjtime = cpts_ptp_adjtime,
315 .gettime64 = cpts_ptp_gettime,
316 .settime64 = cpts_ptp_settime,
317 .enable = cpts_ptp_enable,
318 .do_aux_work = cpts_overflow_check,
319 };
320
321 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
322 u16 ts_seqid, u8 ts_msgtype)
323 {
324 u16 *seqid;
325 unsigned int offset = 0;
326 u8 *msgtype, *data = skb->data;
327
328 if (ptp_class & PTP_CLASS_VLAN)
329 offset += VLAN_HLEN;
330
331 switch (ptp_class & PTP_CLASS_PMASK) {
332 case PTP_CLASS_IPV4:
333 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
334 break;
335 case PTP_CLASS_IPV6:
336 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
337 break;
338 case PTP_CLASS_L2:
339 offset += ETH_HLEN;
340 break;
341 default:
342 return 0;
343 }
344
345 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
346 return 0;
347
348 if (unlikely(ptp_class & PTP_CLASS_V1))
349 msgtype = data + offset + OFF_PTP_CONTROL;
350 else
351 msgtype = data + offset;
352
353 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
354
355 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
356 }
357
358 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
359 {
360 u64 ns = 0;
361 struct cpts_event *event;
362 struct list_head *this, *next;
363 unsigned int class = ptp_classify_raw(skb);
364 unsigned long flags;
365 u16 seqid;
366 u8 mtype;
367
368 if (class == PTP_CLASS_NONE)
369 return 0;
370
371 spin_lock_irqsave(&cpts->lock, flags);
372 cpts_fifo_read(cpts, -1);
373 list_for_each_safe(this, next, &cpts->events) {
374 event = list_entry(this, struct cpts_event, list);
375 if (event_expired(event)) {
376 list_del_init(&event->list);
377 list_add(&event->list, &cpts->pool);
378 continue;
379 }
380 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
381 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
382 if (ev_type == event_type(event) &&
383 cpts_match(skb, class, seqid, mtype)) {
384 ns = timecounter_cyc2time(&cpts->tc, event->low);
385 list_del_init(&event->list);
386 list_add(&event->list, &cpts->pool);
387 break;
388 }
389 }
390
391 if (ev_type == CPTS_EV_TX && !ns) {
392 struct cpts_skb_cb_data *skb_cb =
393 (struct cpts_skb_cb_data *)skb->cb;
394 /* Not found, add frame to queue for processing later.
395 * The periodic FIFO check will handle this.
396 */
397 skb_get(skb);
398 /* get the timestamp for timeouts */
399 skb_cb->tmo = jiffies + msecs_to_jiffies(100);
400 __skb_queue_tail(&cpts->txq, skb);
401 ptp_schedule_worker(cpts->clock, 0);
402 }
403 spin_unlock_irqrestore(&cpts->lock, flags);
404
405 return ns;
406 }
407
408 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
409 {
410 u64 ns;
411 struct skb_shared_hwtstamps *ssh;
412
413 if (!cpts->rx_enable)
414 return;
415 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
416 if (!ns)
417 return;
418 ssh = skb_hwtstamps(skb);
419 memset(ssh, 0, sizeof(*ssh));
420 ssh->hwtstamp = ns_to_ktime(ns);
421 }
422 EXPORT_SYMBOL_GPL(cpts_rx_timestamp);
423
424 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
425 {
426 u64 ns;
427 struct skb_shared_hwtstamps ssh;
428
429 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
430 return;
431 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
432 if (!ns)
433 return;
434 memset(&ssh, 0, sizeof(ssh));
435 ssh.hwtstamp = ns_to_ktime(ns);
436 skb_tstamp_tx(skb, &ssh);
437 }
438 EXPORT_SYMBOL_GPL(cpts_tx_timestamp);
439
440 int cpts_register(struct cpts *cpts)
441 {
442 int err, i;
443
444 skb_queue_head_init(&cpts->txq);
445 INIT_LIST_HEAD(&cpts->events);
446 INIT_LIST_HEAD(&cpts->pool);
447 for (i = 0; i < CPTS_MAX_EVENTS; i++)
448 list_add(&cpts->pool_data[i].list, &cpts->pool);
449
450 clk_enable(cpts->refclk);
451
452 cpts_write32(cpts, CPTS_EN, control);
453 cpts_write32(cpts, TS_PEND_EN, int_enable);
454
455 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
456
457 cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
458 if (IS_ERR(cpts->clock)) {
459 err = PTR_ERR(cpts->clock);
460 cpts->clock = NULL;
461 goto err_ptp;
462 }
463 cpts->phc_index = ptp_clock_index(cpts->clock);
464
465 ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
466 return 0;
467
468 err_ptp:
469 clk_disable(cpts->refclk);
470 return err;
471 }
472 EXPORT_SYMBOL_GPL(cpts_register);
473
474 void cpts_unregister(struct cpts *cpts)
475 {
476 if (WARN_ON(!cpts->clock))
477 return;
478
479 ptp_clock_unregister(cpts->clock);
480 cpts->clock = NULL;
481
482 cpts_write32(cpts, 0, int_enable);
483 cpts_write32(cpts, 0, control);
484
485 /* Drop all packet */
486 skb_queue_purge(&cpts->txq);
487
488 clk_disable(cpts->refclk);
489 }
490 EXPORT_SYMBOL_GPL(cpts_unregister);
491
492 static void cpts_calc_mult_shift(struct cpts *cpts)
493 {
494 u64 frac, maxsec, ns;
495 u32 freq;
496
497 freq = clk_get_rate(cpts->refclk);
498
499 /* Calc the maximum number of seconds which we can run before
500 * wrapping around.
501 */
502 maxsec = cpts->cc.mask;
503 do_div(maxsec, freq);
504 /* limit conversation rate to 10 sec as higher values will produce
505 * too small mult factors and so reduce the conversion accuracy
506 */
507 if (maxsec > 10)
508 maxsec = 10;
509
510 /* Calc overflow check period (maxsec / 2) */
511 cpts->ov_check_period = (HZ * maxsec) / 2;
512 dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n",
513 cpts->ov_check_period);
514
515 if (cpts->cc.mult || cpts->cc.shift)
516 return;
517
518 clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift,
519 freq, NSEC_PER_SEC, maxsec);
520
521 frac = 0;
522 ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac);
523
524 dev_info(cpts->dev,
525 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n",
526 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
527 }
528
529 static int cpts_of_parse(struct cpts *cpts, struct device_node *node)
530 {
531 int ret = -EINVAL;
532 u32 prop;
533
534 if (!of_property_read_u32(node, "cpts_clock_mult", &prop))
535 cpts->cc.mult = prop;
536
537 if (!of_property_read_u32(node, "cpts_clock_shift", &prop))
538 cpts->cc.shift = prop;
539
540 if ((cpts->cc.mult && !cpts->cc.shift) ||
541 (!cpts->cc.mult && cpts->cc.shift))
542 goto of_error;
543
544 return 0;
545
546 of_error:
547 dev_err(cpts->dev, "CPTS: Missing property in the DT.\n");
548 return ret;
549 }
550
551 struct cpts *cpts_create(struct device *dev, void __iomem *regs,
552 struct device_node *node)
553 {
554 struct cpts *cpts;
555 int ret;
556
557 cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL);
558 if (!cpts)
559 return ERR_PTR(-ENOMEM);
560
561 cpts->dev = dev;
562 cpts->reg = (struct cpsw_cpts __iomem *)regs;
563 spin_lock_init(&cpts->lock);
564
565 ret = cpts_of_parse(cpts, node);
566 if (ret)
567 return ERR_PTR(ret);
568
569 cpts->refclk = devm_clk_get(dev, "cpts");
570 if (IS_ERR(cpts->refclk)) {
571 dev_err(dev, "Failed to get cpts refclk\n");
572 return ERR_CAST(cpts->refclk);
573 }
574
575 clk_prepare(cpts->refclk);
576
577 cpts->cc.read = cpts_systim_read;
578 cpts->cc.mask = CLOCKSOURCE_MASK(32);
579 cpts->info = cpts_info;
580
581 cpts_calc_mult_shift(cpts);
582 /* save cc.mult original value as it can be modified
583 * by cpts_ptp_adjfreq().
584 */
585 cpts->cc_mult = cpts->cc.mult;
586
587 return cpts;
588 }
589 EXPORT_SYMBOL_GPL(cpts_create);
590
591 void cpts_release(struct cpts *cpts)
592 {
593 if (!cpts)
594 return;
595
596 if (WARN_ON(!cpts->refclk))
597 return;
598
599 clk_unprepare(cpts->refclk);
600 }
601 EXPORT_SYMBOL_GPL(cpts_release);
602
603 MODULE_LICENSE("GPL v2");
604 MODULE_DESCRIPTION("TI CPTS driver");
605 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
Linux with added FPC-III support