Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
4 */
5
6#include <linux/kernel.h>
7#include <linux/init.h>
8#include <linux/types.h>
9#include <linux/device.h>
10#include <linux/io.h>
11#include <linux/err.h>
12#include <linux/export.h>
13#include <linux/slab.h>
14#include <linux/stringhash.h>
15#include <linux/mutex.h>
16#include <linux/clk.h>
17#include <linux/coresight.h>
18#include <linux/of_platform.h>
19#include <linux/delay.h>
20#include <linux/pm_runtime.h>
21
22#include "coresight-etm-perf.h"
23#include "coresight-priv.h"
24#include "coresight-syscfg.h"
25
26static DEFINE_MUTEX(coresight_mutex);
27static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);
28
29/**
30 * struct coresight_node - elements of a path, from source to sink
31 * @csdev: Address of an element.
32 * @link: hook to the list.
33 */
34struct coresight_node {
35 struct coresight_device *csdev;
36 struct list_head link;
37};
38
39/*
40 * When operating Coresight drivers from the sysFS interface, only a single
41 * path can exist from a tracer (associated to a CPU) to a sink.
42 */
43static DEFINE_PER_CPU(struct list_head *, tracer_path);
44
45/*
46 * As of this writing only a single STM can be found in CS topologies. Since
47 * there is no way to know if we'll ever see more and what kind of
48 * configuration they will enact, for the time being only define a single path
49 * for STM.
50 */
51static struct list_head *stm_path;
52
53/*
54 * When losing synchronisation a new barrier packet needs to be inserted at the
55 * beginning of the data collected in a buffer. That way the decoder knows that
56 * it needs to look for another sync sequence.
57 */
58const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
59EXPORT_SYMBOL_GPL(coresight_barrier_pkt);
60
61static const struct cti_assoc_op *cti_assoc_ops;
62
63ssize_t coresight_simple_show_pair(struct device *_dev,
64 struct device_attribute *attr, char *buf)
65{
66 struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
67 struct cs_pair_attribute *cs_attr = container_of(attr, struct cs_pair_attribute, attr);
68 u64 val;
69
70 pm_runtime_get_sync(_dev->parent);
71 val = csdev_access_relaxed_read_pair(&csdev->access, cs_attr->lo_off, cs_attr->hi_off);
72 pm_runtime_put_sync(_dev->parent);
73 return sysfs_emit(buf, "0x%llx\n", val);
74}
75EXPORT_SYMBOL_GPL(coresight_simple_show_pair);
76
77ssize_t coresight_simple_show32(struct device *_dev,
78 struct device_attribute *attr, char *buf)
79{
80 struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
81 struct cs_off_attribute *cs_attr = container_of(attr, struct cs_off_attribute, attr);
82 u64 val;
83
84 pm_runtime_get_sync(_dev->parent);
85 val = csdev_access_relaxed_read32(&csdev->access, cs_attr->off);
86 pm_runtime_put_sync(_dev->parent);
87 return sysfs_emit(buf, "0x%llx\n", val);
88}
89EXPORT_SYMBOL_GPL(coresight_simple_show32);
90
91void coresight_set_cti_ops(const struct cti_assoc_op *cti_op)
92{
93 cti_assoc_ops = cti_op;
94}
95EXPORT_SYMBOL_GPL(coresight_set_cti_ops);
96
97void coresight_remove_cti_ops(void)
98{
99 cti_assoc_ops = NULL;
100}
101EXPORT_SYMBOL_GPL(coresight_remove_cti_ops);
102
103void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev)
104{
105 per_cpu(csdev_sink, cpu) = csdev;
106}
107EXPORT_SYMBOL_GPL(coresight_set_percpu_sink);
108
109struct coresight_device *coresight_get_percpu_sink(int cpu)
110{
111 return per_cpu(csdev_sink, cpu);
112}
113EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);
114
115static int coresight_id_match(struct device *dev, void *data)
116{
117 int trace_id, i_trace_id;
118 struct coresight_device *csdev, *i_csdev;
119
120 csdev = data;
121 i_csdev = to_coresight_device(dev);
122
123 /*
124 * No need to care about oneself and components that are not
125 * sources or not enabled
126 */
127 if (i_csdev == csdev || !i_csdev->enable ||
128 i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
129 return 0;
130
131 /* Get the source ID for both components */
132 trace_id = source_ops(csdev)->trace_id(csdev);
133 i_trace_id = source_ops(i_csdev)->trace_id(i_csdev);
134
135 /* All you need is one */
136 if (trace_id == i_trace_id)
137 return 1;
138
139 return 0;
140}
141
142static int coresight_source_is_unique(struct coresight_device *csdev)
143{
144 int trace_id = source_ops(csdev)->trace_id(csdev);
145
146 /* this shouldn't happen */
147 if (trace_id < 0)
148 return 0;
149
150 return !bus_for_each_dev(&coresight_bustype, NULL,
151 csdev, coresight_id_match);
152}
153
154static int coresight_find_link_inport(struct coresight_device *csdev,
155 struct coresight_device *parent)
156{
157 int i;
158 struct coresight_connection *conn;
159
160 for (i = 0; i < parent->pdata->nr_outport; i++) {
161 conn = &parent->pdata->conns[i];
162 if (conn->child_dev == csdev)
163 return conn->child_port;
164 }
165
166 dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
167 dev_name(&parent->dev), dev_name(&csdev->dev));
168
169 return -ENODEV;
170}
171
172static int coresight_find_link_outport(struct coresight_device *csdev,
173 struct coresight_device *child)
174{
175 int i;
176 struct coresight_connection *conn;
177
178 for (i = 0; i < csdev->pdata->nr_outport; i++) {
179 conn = &csdev->pdata->conns[i];
180 if (conn->child_dev == child)
181 return conn->outport;
182 }
183
184 dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
185 dev_name(&csdev->dev), dev_name(&child->dev));
186
187 return -ENODEV;
188}
189
190static inline u32 coresight_read_claim_tags(struct coresight_device *csdev)
191{
192 return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR);
193}
194
195static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev)
196{
197 return coresight_read_claim_tags(csdev) == CORESIGHT_CLAIM_SELF_HOSTED;
198}
199
200static inline bool coresight_is_claimed_any(struct coresight_device *csdev)
201{
202 return coresight_read_claim_tags(csdev) != 0;
203}
204
205static inline void coresight_set_claim_tags(struct coresight_device *csdev)
206{
207 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
208 CORESIGHT_CLAIMSET);
209 isb();
210}
211
212static inline void coresight_clear_claim_tags(struct coresight_device *csdev)
213{
214 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
215 CORESIGHT_CLAIMCLR);
216 isb();
217}
218
219/*
220 * coresight_claim_device_unlocked : Claim the device for self-hosted usage
221 * to prevent an external tool from touching this device. As per PSCI
222 * standards, section "Preserving the execution context" => "Debug and Trace
223 * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and
224 * DBGCLAIM[0] is reserved for external tools.
225 *
226 * Called with CS_UNLOCKed for the component.
227 * Returns : 0 on success
228 */
229int coresight_claim_device_unlocked(struct coresight_device *csdev)
230{
231 if (WARN_ON(!csdev))
232 return -EINVAL;
233
234 if (coresight_is_claimed_any(csdev))
235 return -EBUSY;
236
237 coresight_set_claim_tags(csdev);
238 if (coresight_is_claimed_self_hosted(csdev))
239 return 0;
240 /* There was a race setting the tags, clean up and fail */
241 coresight_clear_claim_tags(csdev);
242 return -EBUSY;
243}
244EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);
245
246int coresight_claim_device(struct coresight_device *csdev)
247{
248 int rc;
249
250 if (WARN_ON(!csdev))
251 return -EINVAL;
252
253 CS_UNLOCK(csdev->access.base);
254 rc = coresight_claim_device_unlocked(csdev);
255 CS_LOCK(csdev->access.base);
256
257 return rc;
258}
259EXPORT_SYMBOL_GPL(coresight_claim_device);
260
261/*
262 * coresight_disclaim_device_unlocked : Clear the claim tags for the device.
263 * Called with CS_UNLOCKed for the component.
264 */
265void coresight_disclaim_device_unlocked(struct coresight_device *csdev)
266{
267
268 if (WARN_ON(!csdev))
269 return;
270
271 if (coresight_is_claimed_self_hosted(csdev))
272 coresight_clear_claim_tags(csdev);
273 else
274 /*
275 * The external agent may have not honoured our claim
276 * and has manipulated it. Or something else has seriously
277 * gone wrong in our driver.
278 */
279 WARN_ON_ONCE(1);
280}
281EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
282
283void coresight_disclaim_device(struct coresight_device *csdev)
284{
285 if (WARN_ON(!csdev))
286 return;
287
288 CS_UNLOCK(csdev->access.base);
289 coresight_disclaim_device_unlocked(csdev);
290 CS_LOCK(csdev->access.base);
291}
292EXPORT_SYMBOL_GPL(coresight_disclaim_device);
293
294/* enable or disable an associated CTI device of the supplied CS device */
295static int
296coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
297{
298 int ect_ret = 0;
299 struct coresight_device *ect_csdev = csdev->ect_dev;
300 struct module *mod;
301
302 if (!ect_csdev)
303 return 0;
304 if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable))
305 return 0;
306
307 mod = ect_csdev->dev.parent->driver->owner;
308 if (enable) {
309 if (try_module_get(mod)) {
310 ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
311 if (ect_ret) {
312 module_put(mod);
313 } else {
314 get_device(ect_csdev->dev.parent);
315 csdev->ect_enabled = true;
316 }
317 } else
318 ect_ret = -ENODEV;
319 } else {
320 if (csdev->ect_enabled) {
321 ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
322 put_device(ect_csdev->dev.parent);
323 module_put(mod);
324 csdev->ect_enabled = false;
325 }
326 }
327
328 /* output warning if ECT enable is preventing trace operation */
329 if (ect_ret)
330 dev_info(&csdev->dev, "Associated ECT device (%s) %s failed\n",
331 dev_name(&ect_csdev->dev),
332 enable ? "enable" : "disable");
333 return ect_ret;
334}
335
336/*
337 * Set the associated ect / cti device while holding the coresight_mutex
338 * to avoid a race with coresight_enable that may try to use this value.
339 */
340void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev,
341 struct coresight_device *ect_csdev)
342{
343 mutex_lock(&coresight_mutex);
344 csdev->ect_dev = ect_csdev;
345 mutex_unlock(&coresight_mutex);
346}
347EXPORT_SYMBOL_GPL(coresight_set_assoc_ectdev_mutex);
348
349static int coresight_enable_sink(struct coresight_device *csdev,
350 u32 mode, void *data)
351{
352 int ret;
353
354 /*
355 * We need to make sure the "new" session is compatible with the
356 * existing "mode" of operation.
357 */
358 if (!sink_ops(csdev)->enable)
359 return -EINVAL;
360
361 ret = coresight_control_assoc_ectdev(csdev, true);
362 if (ret)
363 return ret;
364 ret = sink_ops(csdev)->enable(csdev, mode, data);
365 if (ret) {
366 coresight_control_assoc_ectdev(csdev, false);
367 return ret;
368 }
369 csdev->enable = true;
370
371 return 0;
372}
373
374static void coresight_disable_sink(struct coresight_device *csdev)
375{
376 int ret;
377
378 if (!sink_ops(csdev)->disable)
379 return;
380
381 ret = sink_ops(csdev)->disable(csdev);
382 if (ret)
383 return;
384 coresight_control_assoc_ectdev(csdev, false);
385 csdev->enable = false;
386}
387
388static int coresight_enable_link(struct coresight_device *csdev,
389 struct coresight_device *parent,
390 struct coresight_device *child)
391{
392 int ret = 0;
393 int link_subtype;
394 int inport, outport;
395
396 if (!parent || !child)
397 return -EINVAL;
398
399 inport = coresight_find_link_inport(csdev, parent);
400 outport = coresight_find_link_outport(csdev, child);
401 link_subtype = csdev->subtype.link_subtype;
402
403 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && inport < 0)
404 return inport;
405 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0)
406 return outport;
407
408 if (link_ops(csdev)->enable) {
409 ret = coresight_control_assoc_ectdev(csdev, true);
410 if (!ret) {
411 ret = link_ops(csdev)->enable(csdev, inport, outport);
412 if (ret)
413 coresight_control_assoc_ectdev(csdev, false);
414 }
415 }
416
417 if (!ret)
418 csdev->enable = true;
419
420 return ret;
421}
422
423static void coresight_disable_link(struct coresight_device *csdev,
424 struct coresight_device *parent,
425 struct coresight_device *child)
426{
427 int i, nr_conns;
428 int link_subtype;
429 int inport, outport;
430
431 if (!parent || !child)
432 return;
433
434 inport = coresight_find_link_inport(csdev, parent);
435 outport = coresight_find_link_outport(csdev, child);
436 link_subtype = csdev->subtype.link_subtype;
437
438 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
439 nr_conns = csdev->pdata->nr_inport;
440 } else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
441 nr_conns = csdev->pdata->nr_outport;
442 } else {
443 nr_conns = 1;
444 }
445
446 if (link_ops(csdev)->disable) {
447 link_ops(csdev)->disable(csdev, inport, outport);
448 coresight_control_assoc_ectdev(csdev, false);
449 }
450
451 for (i = 0; i < nr_conns; i++)
452 if (atomic_read(&csdev->refcnt[i]) != 0)
453 return;
454
455 csdev->enable = false;
456}
457
458static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
459{
460 int ret;
461
462 if (!coresight_source_is_unique(csdev)) {
463 dev_warn(&csdev->dev, "traceID %d not unique\n",
464 source_ops(csdev)->trace_id(csdev));
465 return -EINVAL;
466 }
467
468 if (!csdev->enable) {
469 if (source_ops(csdev)->enable) {
470 ret = coresight_control_assoc_ectdev(csdev, true);
471 if (ret)
472 return ret;
473 ret = source_ops(csdev)->enable(csdev, NULL, mode);
474 if (ret) {
475 coresight_control_assoc_ectdev(csdev, false);
476 return ret;
477 }
478 }
479 csdev->enable = true;
480 }
481
482 atomic_inc(csdev->refcnt);
483
484 return 0;
485}
486
487/**
488 * coresight_disable_source - Drop the reference count by 1 and disable
489 * the device if there are no users left.
490 *
491 * @csdev: The coresight device to disable
492 *
493 * Returns true if the device has been disabled.
494 */
495static bool coresight_disable_source(struct coresight_device *csdev)
496{
497 if (atomic_dec_return(csdev->refcnt) == 0) {
498 if (source_ops(csdev)->disable)
499 source_ops(csdev)->disable(csdev, NULL);
500 coresight_control_assoc_ectdev(csdev, false);
501 csdev->enable = false;
502 }
503 return !csdev->enable;
504}
505
506/*
507 * coresight_disable_path_from : Disable components in the given path beyond
508 * @nd in the list. If @nd is NULL, all the components, except the SOURCE are
509 * disabled.
510 */
511static void coresight_disable_path_from(struct list_head *path,
512 struct coresight_node *nd)
513{
514 u32 type;
515 struct coresight_device *csdev, *parent, *child;
516
517 if (!nd)
518 nd = list_first_entry(path, struct coresight_node, link);
519
520 list_for_each_entry_continue(nd, path, link) {
521 csdev = nd->csdev;
522 type = csdev->type;
523
524 /*
525 * ETF devices are tricky... They can be a link or a sink,
526 * depending on how they are configured. If an ETF has been
527 * "activated" it will be configured as a sink, otherwise
528 * go ahead with the link configuration.
529 */
530 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
531 type = (csdev == coresight_get_sink(path)) ?
532 CORESIGHT_DEV_TYPE_SINK :
533 CORESIGHT_DEV_TYPE_LINK;
534
535 switch (type) {
536 case CORESIGHT_DEV_TYPE_SINK:
537 coresight_disable_sink(csdev);
538 break;
539 case CORESIGHT_DEV_TYPE_SOURCE:
540 /*
541 * We skip the first node in the path assuming that it
542 * is the source. So we don't expect a source device in
543 * the middle of a path.
544 */
545 WARN_ON(1);
546 break;
547 case CORESIGHT_DEV_TYPE_LINK:
548 parent = list_prev_entry(nd, link)->csdev;
549 child = list_next_entry(nd, link)->csdev;
550 coresight_disable_link(csdev, parent, child);
551 break;
552 default:
553 break;
554 }
555 }
556}
557
558void coresight_disable_path(struct list_head *path)
559{
560 coresight_disable_path_from(path, NULL);
561}
562EXPORT_SYMBOL_GPL(coresight_disable_path);
563
564int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data)
565{
566
567 int ret = 0;
568 u32 type;
569 struct coresight_node *nd;
570 struct coresight_device *csdev, *parent, *child;
571
572 list_for_each_entry_reverse(nd, path, link) {
573 csdev = nd->csdev;
574 type = csdev->type;
575
576 /*
577 * ETF devices are tricky... They can be a link or a sink,
578 * depending on how they are configured. If an ETF has been
579 * "activated" it will be configured as a sink, otherwise
580 * go ahead with the link configuration.
581 */
582 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
583 type = (csdev == coresight_get_sink(path)) ?
584 CORESIGHT_DEV_TYPE_SINK :
585 CORESIGHT_DEV_TYPE_LINK;
586
587 switch (type) {
588 case CORESIGHT_DEV_TYPE_SINK:
589 ret = coresight_enable_sink(csdev, mode, sink_data);
590 /*
591 * Sink is the first component turned on. If we
592 * failed to enable the sink, there are no components
593 * that need disabling. Disabling the path here
594 * would mean we could disrupt an existing session.
595 */
596 if (ret)
597 goto out;
598 break;
599 case CORESIGHT_DEV_TYPE_SOURCE:
600 /* sources are enabled from either sysFS or Perf */
601 break;
602 case CORESIGHT_DEV_TYPE_LINK:
603 parent = list_prev_entry(nd, link)->csdev;
604 child = list_next_entry(nd, link)->csdev;
605 ret = coresight_enable_link(csdev, parent, child);
606 if (ret)
607 goto err;
608 break;
609 default:
610 goto err;
611 }
612 }
613
614out:
615 return ret;
616err:
617 coresight_disable_path_from(path, nd);
618 goto out;
619}
620
621struct coresight_device *coresight_get_sink(struct list_head *path)
622{
623 struct coresight_device *csdev;
624
625 if (!path)
626 return NULL;
627
628 csdev = list_last_entry(path, struct coresight_node, link)->csdev;
629 if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
630 csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
631 return NULL;
632
633 return csdev;
634}
635
636static struct coresight_device *
637coresight_find_enabled_sink(struct coresight_device *csdev)
638{
639 int i;
640 struct coresight_device *sink = NULL;
641
642 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
643 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
644 csdev->activated)
645 return csdev;
646
647 /*
648 * Recursively explore each port found on this element.
649 */
650 for (i = 0; i < csdev->pdata->nr_outport; i++) {
651 struct coresight_device *child_dev;
652
653 child_dev = csdev->pdata->conns[i].child_dev;
654 if (child_dev)
655 sink = coresight_find_enabled_sink(child_dev);
656 if (sink)
657 return sink;
658 }
659
660 return NULL;
661}
662
663/**
664 * coresight_get_enabled_sink - returns the first enabled sink using
665 * connection based search starting from the source reference
666 *
667 * @source: Coresight source device reference
668 */
669struct coresight_device *
670coresight_get_enabled_sink(struct coresight_device *source)
671{
672 if (!source)
673 return NULL;
674
675 return coresight_find_enabled_sink(source);
676}
677
678static int coresight_sink_by_id(struct device *dev, const void *data)
679{
680 struct coresight_device *csdev = to_coresight_device(dev);
681 unsigned long hash;
682
683 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
684 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
685
686 if (!csdev->ea)
687 return 0;
688 /*
689 * See function etm_perf_add_symlink_sink() to know where
690 * this comes from.
691 */
692 hash = (unsigned long)csdev->ea->var;
693
694 if ((u32)hash == *(u32 *)data)
695 return 1;
696 }
697
698 return 0;
699}
700
701/**
702 * coresight_get_sink_by_id - returns the sink that matches the id
703 * @id: Id of the sink to match
704 *
705 * The name of a sink is unique, whether it is found on the AMBA bus or
706 * otherwise. As such the hash of that name can easily be used to identify
707 * a sink.
708 */
709struct coresight_device *coresight_get_sink_by_id(u32 id)
710{
711 struct device *dev = NULL;
712
713 dev = bus_find_device(&coresight_bustype, NULL, &id,
714 coresight_sink_by_id);
715
716 return dev ? to_coresight_device(dev) : NULL;
717}
718
719/**
720 * coresight_get_ref- Helper function to increase reference count to module
721 * and device.
722 *
723 * @csdev: The coresight device to get a reference on.
724 *
725 * Return true in successful case and power up the device.
726 * Return false when failed to get reference of module.
727 */
728static inline bool coresight_get_ref(struct coresight_device *csdev)
729{
730 struct device *dev = csdev->dev.parent;
731
732 /* Make sure the driver can't be removed */
733 if (!try_module_get(dev->driver->owner))
734 return false;
735 /* Make sure the device can't go away */
736 get_device(dev);
737 pm_runtime_get_sync(dev);
738 return true;
739}
740
741/**
742 * coresight_put_ref- Helper function to decrease reference count to module
743 * and device. Power off the device.
744 *
745 * @csdev: The coresight device to decrement a reference from.
746 */
747static inline void coresight_put_ref(struct coresight_device *csdev)
748{
749 struct device *dev = csdev->dev.parent;
750
751 pm_runtime_put(dev);
752 put_device(dev);
753 module_put(dev->driver->owner);
754}
755
756/*
757 * coresight_grab_device - Power up this device and any of the helper
758 * devices connected to it for trace operation. Since the helper devices
759 * don't appear on the trace path, they should be handled along with the
760 * master device.
761 */
762static int coresight_grab_device(struct coresight_device *csdev)
763{
764 int i;
765
766 for (i = 0; i < csdev->pdata->nr_outport; i++) {
767 struct coresight_device *child;
768
769 child = csdev->pdata->conns[i].child_dev;
770 if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
771 if (!coresight_get_ref(child))
772 goto err;
773 }
774 if (coresight_get_ref(csdev))
775 return 0;
776err:
777 for (i--; i >= 0; i--) {
778 struct coresight_device *child;
779
780 child = csdev->pdata->conns[i].child_dev;
781 if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
782 coresight_put_ref(child);
783 }
784 return -ENODEV;
785}
786
787/*
788 * coresight_drop_device - Release this device and any of the helper
789 * devices connected to it.
790 */
791static void coresight_drop_device(struct coresight_device *csdev)
792{
793 int i;
794
795 coresight_put_ref(csdev);
796 for (i = 0; i < csdev->pdata->nr_outport; i++) {
797 struct coresight_device *child;
798
799 child = csdev->pdata->conns[i].child_dev;
800 if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
801 coresight_put_ref(child);
802 }
803}
804
805/**
806 * _coresight_build_path - recursively build a path from a @csdev to a sink.
807 * @csdev: The device to start from.
808 * @sink: The final sink we want in this path.
809 * @path: The list to add devices to.
810 *
811 * The tree of Coresight device is traversed until an activated sink is
812 * found. From there the sink is added to the list along with all the
813 * devices that led to that point - the end result is a list from source
814 * to sink. In that list the source is the first device and the sink the
815 * last one.
816 */
817static int _coresight_build_path(struct coresight_device *csdev,
818 struct coresight_device *sink,
819 struct list_head *path)
820{
821 int i, ret;
822 bool found = false;
823 struct coresight_node *node;
824
825 /* An activated sink has been found. Enqueue the element */
826 if (csdev == sink)
827 goto out;
828
829 if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) &&
830 sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) {
831 if (_coresight_build_path(sink, sink, path) == 0) {
832 found = true;
833 goto out;
834 }
835 }
836
837 /* Not a sink - recursively explore each port found on this element */
838 for (i = 0; i < csdev->pdata->nr_outport; i++) {
839 struct coresight_device *child_dev;
840
841 child_dev = csdev->pdata->conns[i].child_dev;
842 if (child_dev &&
843 _coresight_build_path(child_dev, sink, path) == 0) {
844 found = true;
845 break;
846 }
847 }
848
849 if (!found)
850 return -ENODEV;
851
852out:
853 /*
854 * A path from this element to a sink has been found. The elements
855 * leading to the sink are already enqueued, all that is left to do
856 * is tell the PM runtime core we need this element and add a node
857 * for it.
858 */
859 ret = coresight_grab_device(csdev);
860 if (ret)
861 return ret;
862
863 node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
864 if (!node)
865 return -ENOMEM;
866
867 node->csdev = csdev;
868 list_add(&node->link, path);
869
870 return 0;
871}
872
873struct list_head *coresight_build_path(struct coresight_device *source,
874 struct coresight_device *sink)
875{
876 struct list_head *path;
877 int rc;
878
879 if (!sink)
880 return ERR_PTR(-EINVAL);
881
882 path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
883 if (!path)
884 return ERR_PTR(-ENOMEM);
885
886 INIT_LIST_HEAD(path);
887
888 rc = _coresight_build_path(source, sink, path);
889 if (rc) {
890 kfree(path);
891 return ERR_PTR(rc);
892 }
893
894 return path;
895}
896
897/**
898 * coresight_release_path - release a previously built path.
899 * @path: the path to release.
900 *
901 * Go through all the elements of a path and 1) removed it from the list and
902 * 2) free the memory allocated for each node.
903 */
904void coresight_release_path(struct list_head *path)
905{
906 struct coresight_device *csdev;
907 struct coresight_node *nd, *next;
908
909 list_for_each_entry_safe(nd, next, path, link) {
910 csdev = nd->csdev;
911
912 coresight_drop_device(csdev);
913 list_del(&nd->link);
914 kfree(nd);
915 }
916
917 kfree(path);
918}
919
920/* return true if the device is a suitable type for a default sink */
921static inline bool coresight_is_def_sink_type(struct coresight_device *csdev)
922{
923 /* sink & correct subtype */
924 if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
925 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) &&
926 (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER))
927 return true;
928 return false;
929}
930
931/**
932 * coresight_select_best_sink - return the best sink for use as default from
933 * the two provided.
934 *
935 * @sink: current best sink.
936 * @depth: search depth where current sink was found.
937 * @new_sink: new sink for comparison with current sink.
938 * @new_depth: search depth where new sink was found.
939 *
940 * Sinks prioritised according to coresight_dev_subtype_sink, with only
941 * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used.
942 *
943 * Where two sinks of equal priority are found, the sink closest to the
944 * source is used (smallest search depth).
945 *
946 * return @new_sink & update @depth if better than @sink, else return @sink.
947 */
948static struct coresight_device *
949coresight_select_best_sink(struct coresight_device *sink, int *depth,
950 struct coresight_device *new_sink, int new_depth)
951{
952 bool update = false;
953
954 if (!sink) {
955 /* first found at this level */
956 update = true;
957 } else if (new_sink->subtype.sink_subtype >
958 sink->subtype.sink_subtype) {
959 /* found better sink */
960 update = true;
961 } else if ((new_sink->subtype.sink_subtype ==
962 sink->subtype.sink_subtype) &&
963 (*depth > new_depth)) {
964 /* found same but closer sink */
965 update = true;
966 }
967
968 if (update)
969 *depth = new_depth;
970 return update ? new_sink : sink;
971}
972
973/**
974 * coresight_find_sink - recursive function to walk trace connections from
975 * source to find a suitable default sink.
976 *
977 * @csdev: source / current device to check.
978 * @depth: [in] search depth of calling dev, [out] depth of found sink.
979 *
980 * This will walk the connection path from a source (ETM) till a suitable
981 * sink is encountered and return that sink to the original caller.
982 *
983 * If current device is a plain sink return that & depth, otherwise recursively
984 * call child connections looking for a sink. Select best possible using
985 * coresight_select_best_sink.
986 *
987 * return best sink found, or NULL if not found at this node or child nodes.
988 */
989static struct coresight_device *
990coresight_find_sink(struct coresight_device *csdev, int *depth)
991{
992 int i, curr_depth = *depth + 1, found_depth = 0;
993 struct coresight_device *found_sink = NULL;
994
995 if (coresight_is_def_sink_type(csdev)) {
996 found_depth = curr_depth;
997 found_sink = csdev;
998 if (csdev->type == CORESIGHT_DEV_TYPE_SINK)
999 goto return_def_sink;
1000 /* look past LINKSINK for something better */
1001 }
1002
1003 /*
1004 * Not a sink we want - or possible child sink may be better.
1005 * recursively explore each port found on this element.
1006 */
1007 for (i = 0; i < csdev->pdata->nr_outport; i++) {
1008 struct coresight_device *child_dev, *sink = NULL;
1009 int child_depth = curr_depth;
1010
1011 child_dev = csdev->pdata->conns[i].child_dev;
1012 if (child_dev)
1013 sink = coresight_find_sink(child_dev, &child_depth);
1014
1015 if (sink)
1016 found_sink = coresight_select_best_sink(found_sink,
1017 &found_depth,
1018 sink,
1019 child_depth);
1020 }
1021
1022return_def_sink:
1023 /* return found sink and depth */
1024 if (found_sink)
1025 *depth = found_depth;
1026 return found_sink;
1027}
1028
1029/**
1030 * coresight_find_default_sink: Find a sink suitable for use as a
1031 * default sink.
1032 *
1033 * @csdev: starting source to find a connected sink.
1034 *
1035 * Walks connections graph looking for a suitable sink to enable for the
1036 * supplied source. Uses CoreSight device subtypes and distance from source
1037 * to select the best sink.
1038 *
1039 * If a sink is found, then the default sink for this device is set and
1040 * will be automatically used in future.
1041 *
1042 * Used in cases where the CoreSight user (perf / sysfs) has not selected a
1043 * sink.
1044 */
1045struct coresight_device *
1046coresight_find_default_sink(struct coresight_device *csdev)
1047{
1048 int depth = 0;
1049
1050 /* look for a default sink if we have not found for this device */
1051 if (!csdev->def_sink) {
1052 if (coresight_is_percpu_source(csdev))
1053 csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev));
1054 if (!csdev->def_sink)
1055 csdev->def_sink = coresight_find_sink(csdev, &depth);
1056 }
1057 return csdev->def_sink;
1058}
1059
1060static int coresight_remove_sink_ref(struct device *dev, void *data)
1061{
1062 struct coresight_device *sink = data;
1063 struct coresight_device *source = to_coresight_device(dev);
1064
1065 if (source->def_sink == sink)
1066 source->def_sink = NULL;
1067 return 0;
1068}
1069
1070/**
1071 * coresight_clear_default_sink: Remove all default sink references to the
1072 * supplied sink.
1073 *
1074 * If supplied device is a sink, then check all the bus devices and clear
1075 * out all the references to this sink from the coresight_device def_sink
1076 * parameter.
1077 *
1078 * @csdev: coresight sink - remove references to this from all sources.
1079 */
1080static void coresight_clear_default_sink(struct coresight_device *csdev)
1081{
1082 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
1083 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) {
1084 bus_for_each_dev(&coresight_bustype, NULL, csdev,
1085 coresight_remove_sink_ref);
1086 }
1087}
1088
1089/** coresight_validate_source - make sure a source has the right credentials
1090 * @csdev: the device structure for a source.
1091 * @function: the function this was called from.
1092 *
1093 * Assumes the coresight_mutex is held.
1094 */
1095static int coresight_validate_source(struct coresight_device *csdev,
1096 const char *function)
1097{
1098 u32 type, subtype;
1099
1100 type = csdev->type;
1101 subtype = csdev->subtype.source_subtype;
1102
1103 if (type != CORESIGHT_DEV_TYPE_SOURCE) {
1104 dev_err(&csdev->dev, "wrong device type in %s\n", function);
1105 return -EINVAL;
1106 }
1107
1108 if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
1109 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) {
1110 dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
1111 return -EINVAL;
1112 }
1113
1114 return 0;
1115}
1116
1117int coresight_enable(struct coresight_device *csdev)
1118{
1119 int cpu, ret = 0;
1120 struct coresight_device *sink;
1121 struct list_head *path;
1122 enum coresight_dev_subtype_source subtype;
1123
1124 subtype = csdev->subtype.source_subtype;
1125
1126 mutex_lock(&coresight_mutex);
1127
1128 ret = coresight_validate_source(csdev, __func__);
1129 if (ret)
1130 goto out;
1131
1132 if (csdev->enable) {
1133 /*
1134 * There could be multiple applications driving the software
1135 * source. So keep the refcount for each such user when the
1136 * source is already enabled.
1137 */
1138 if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
1139 atomic_inc(csdev->refcnt);
1140 goto out;
1141 }
1142
1143 sink = coresight_get_enabled_sink(csdev);
1144 if (!sink) {
1145 ret = -EINVAL;
1146 goto out;
1147 }
1148
1149 path = coresight_build_path(csdev, sink);
1150 if (IS_ERR(path)) {
1151 pr_err("building path(s) failed\n");
1152 ret = PTR_ERR(path);
1153 goto out;
1154 }
1155
1156 ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
1157 if (ret)
1158 goto err_path;
1159
1160 ret = coresight_enable_source(csdev, CS_MODE_SYSFS);
1161 if (ret)
1162 goto err_source;
1163
1164 switch (subtype) {
1165 case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
1166 /*
1167 * When working from sysFS it is important to keep track
1168 * of the paths that were created so that they can be
1169 * undone in 'coresight_disable()'. Since there can only
1170 * be a single session per tracer (when working from sysFS)
1171 * a per-cpu variable will do just fine.
1172 */
1173 cpu = source_ops(csdev)->cpu_id(csdev);
1174 per_cpu(tracer_path, cpu) = path;
1175 break;
1176 case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
1177 stm_path = path;
1178 break;
1179 default:
1180 /* We can't be here */
1181 break;
1182 }
1183
1184out:
1185 mutex_unlock(&coresight_mutex);
1186 return ret;
1187
1188err_source:
1189 coresight_disable_path(path);
1190
1191err_path:
1192 coresight_release_path(path);
1193 goto out;
1194}
1195EXPORT_SYMBOL_GPL(coresight_enable);
1196
1197void coresight_disable(struct coresight_device *csdev)
1198{
1199 int cpu, ret;
1200 struct list_head *path = NULL;
1201
1202 mutex_lock(&coresight_mutex);
1203
1204 ret = coresight_validate_source(csdev, __func__);
1205 if (ret)
1206 goto out;
1207
1208 if (!csdev->enable || !coresight_disable_source(csdev))
1209 goto out;
1210
1211 switch (csdev->subtype.source_subtype) {
1212 case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
1213 cpu = source_ops(csdev)->cpu_id(csdev);
1214 path = per_cpu(tracer_path, cpu);
1215 per_cpu(tracer_path, cpu) = NULL;
1216 break;
1217 case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
1218 path = stm_path;
1219 stm_path = NULL;
1220 break;
1221 default:
1222 /* We can't be here */
1223 break;
1224 }
1225
1226 coresight_disable_path(path);
1227 coresight_release_path(path);
1228
1229out:
1230 mutex_unlock(&coresight_mutex);
1231}
1232EXPORT_SYMBOL_GPL(coresight_disable);
1233
1234static ssize_t enable_sink_show(struct device *dev,
1235 struct device_attribute *attr, char *buf)
1236{
1237 struct coresight_device *csdev = to_coresight_device(dev);
1238
1239 return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
1240}
1241
1242static ssize_t enable_sink_store(struct device *dev,
1243 struct device_attribute *attr,
1244 const char *buf, size_t size)
1245{
1246 int ret;
1247 unsigned long val;
1248 struct coresight_device *csdev = to_coresight_device(dev);
1249
1250 ret = kstrtoul(buf, 10, &val);
1251 if (ret)
1252 return ret;
1253
1254 if (val)
1255 csdev->activated = true;
1256 else
1257 csdev->activated = false;
1258
1259 return size;
1260
1261}
1262static DEVICE_ATTR_RW(enable_sink);
1263
1264static ssize_t enable_source_show(struct device *dev,
1265 struct device_attribute *attr, char *buf)
1266{
1267 struct coresight_device *csdev = to_coresight_device(dev);
1268
1269 return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
1270}
1271
1272static ssize_t enable_source_store(struct device *dev,
1273 struct device_attribute *attr,
1274 const char *buf, size_t size)
1275{
1276 int ret = 0;
1277 unsigned long val;
1278 struct coresight_device *csdev = to_coresight_device(dev);
1279
1280 ret = kstrtoul(buf, 10, &val);
1281 if (ret)
1282 return ret;
1283
1284 if (val) {
1285 ret = coresight_enable(csdev);
1286 if (ret)
1287 return ret;
1288 } else {
1289 coresight_disable(csdev);
1290 }
1291
1292 return size;
1293}
1294static DEVICE_ATTR_RW(enable_source);
1295
1296static struct attribute *coresight_sink_attrs[] = {
1297 &dev_attr_enable_sink.attr,
1298 NULL,
1299};
1300ATTRIBUTE_GROUPS(coresight_sink);
1301
1302static struct attribute *coresight_source_attrs[] = {
1303 &dev_attr_enable_source.attr,
1304 NULL,
1305};
1306ATTRIBUTE_GROUPS(coresight_source);
1307
1308static struct device_type coresight_dev_type[] = {
1309 {
1310 .name = "sink",
1311 .groups = coresight_sink_groups,
1312 },
1313 {
1314 .name = "link",
1315 },
1316 {
1317 .name = "linksink",
1318 .groups = coresight_sink_groups,
1319 },
1320 {
1321 .name = "source",
1322 .groups = coresight_source_groups,
1323 },
1324 {
1325 .name = "helper",
1326 },
1327 {
1328 .name = "ect",
1329 },
1330};
1331
1332static void coresight_device_release(struct device *dev)
1333{
1334 struct coresight_device *csdev = to_coresight_device(dev);
1335
1336 fwnode_handle_put(csdev->dev.fwnode);
1337 kfree(csdev->refcnt);
1338 kfree(csdev);
1339}
1340
1341static int coresight_orphan_match(struct device *dev, void *data)
1342{
1343 int i, ret = 0;
1344 bool still_orphan = false;
1345 struct coresight_device *csdev, *i_csdev;
1346 struct coresight_connection *conn;
1347
1348 csdev = data;
1349 i_csdev = to_coresight_device(dev);
1350
1351 /* No need to check oneself */
1352 if (csdev == i_csdev)
1353 return 0;
1354
1355 /* Move on to another component if no connection is orphan */
1356 if (!i_csdev->orphan)
1357 return 0;
1358 /*
1359 * Circle throuch all the connection of that component. If we find
1360 * an orphan connection whose name matches @csdev, link it.
1361 */
1362 for (i = 0; i < i_csdev->pdata->nr_outport; i++) {
1363 conn = &i_csdev->pdata->conns[i];
1364
1365 /* Skip the port if FW doesn't describe it */
1366 if (!conn->child_fwnode)
1367 continue;
1368 /* We have found at least one orphan connection */
1369 if (conn->child_dev == NULL) {
1370 /* Does it match this newly added device? */
1371 if (conn->child_fwnode == csdev->dev.fwnode) {
1372 ret = coresight_make_links(i_csdev,
1373 conn, csdev);
1374 if (ret)
1375 return ret;
1376 } else {
1377 /* This component still has an orphan */
1378 still_orphan = true;
1379 }
1380 }
1381 }
1382
1383 i_csdev->orphan = still_orphan;
1384
1385 /*
1386 * Returning '0' in case we didn't encounter any error,
1387 * ensures that all known component on the bus will be checked.
1388 */
1389 return 0;
1390}
1391
1392static int coresight_fixup_orphan_conns(struct coresight_device *csdev)
1393{
1394 return bus_for_each_dev(&coresight_bustype, NULL,
1395 csdev, coresight_orphan_match);
1396}
1397
1398
1399static int coresight_fixup_device_conns(struct coresight_device *csdev)
1400{
1401 int i, ret = 0;
1402
1403 for (i = 0; i < csdev->pdata->nr_outport; i++) {
1404 struct coresight_connection *conn = &csdev->pdata->conns[i];
1405
1406 if (!conn->child_fwnode)
1407 continue;
1408 conn->child_dev =
1409 coresight_find_csdev_by_fwnode(conn->child_fwnode);
1410 if (conn->child_dev && conn->child_dev->has_conns_grp) {
1411 ret = coresight_make_links(csdev, conn,
1412 conn->child_dev);
1413 if (ret)
1414 break;
1415 } else {
1416 csdev->orphan = true;
1417 }
1418 }
1419
1420 return ret;
1421}
1422
1423static int coresight_remove_match(struct device *dev, void *data)
1424{
1425 int i;
1426 struct coresight_device *csdev, *iterator;
1427 struct coresight_connection *conn;
1428
1429 csdev = data;
1430 iterator = to_coresight_device(dev);
1431
1432 /* No need to check oneself */
1433 if (csdev == iterator)
1434 return 0;
1435
1436 /*
1437 * Circle throuch all the connection of that component. If we find
1438 * a connection whose name matches @csdev, remove it.
1439 */
1440 for (i = 0; i < iterator->pdata->nr_outport; i++) {
1441 conn = &iterator->pdata->conns[i];
1442
1443 if (conn->child_dev == NULL || conn->child_fwnode == NULL)
1444 continue;
1445
1446 if (csdev->dev.fwnode == conn->child_fwnode) {
1447 iterator->orphan = true;
1448 coresight_remove_links(iterator, conn);
1449 /*
1450 * Drop the reference to the handle for the remote
1451 * device acquired in parsing the connections from
1452 * platform data.
1453 */
1454 fwnode_handle_put(conn->child_fwnode);
1455 conn->child_fwnode = NULL;
1456 /* No need to continue */
1457 break;
1458 }
1459 }
1460
1461 /*
1462 * Returning '0' ensures that all known component on the
1463 * bus will be checked.
1464 */
1465 return 0;
1466}
1467
1468/*
1469 * coresight_remove_conns - Remove references to this given devices
1470 * from the connections of other devices.
1471 */
1472static void coresight_remove_conns(struct coresight_device *csdev)
1473{
1474 /*
1475 * Another device will point to this device only if there is
1476 * an output port connected to this one. i.e, if the device
1477 * doesn't have at least one input port, there is no point
1478 * in searching all the devices.
1479 */
1480 if (csdev->pdata->nr_inport)
1481 bus_for_each_dev(&coresight_bustype, NULL,
1482 csdev, coresight_remove_match);
1483}
1484
1485/**
1486 * coresight_timeout - loop until a bit has changed to a specific register
1487 * state.
1488 * @csa: coresight device access for the device
1489 * @offset: Offset of the register from the base of the device.
1490 * @position: the position of the bit of interest.
1491 * @value: the value the bit should have.
1492 *
1493 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
1494 * TIMEOUT_US has elapsed, which ever happens first.
1495 */
1496int coresight_timeout(struct csdev_access *csa, u32 offset,
1497 int position, int value)
1498{
1499 int i;
1500 u32 val;
1501
1502 for (i = TIMEOUT_US; i > 0; i--) {
1503 val = csdev_access_read32(csa, offset);
1504 /* waiting on the bit to go from 0 to 1 */
1505 if (value) {
1506 if (val & BIT(position))
1507 return 0;
1508 /* waiting on the bit to go from 1 to 0 */
1509 } else {
1510 if (!(val & BIT(position)))
1511 return 0;
1512 }
1513
1514 /*
1515 * Delay is arbitrary - the specification doesn't say how long
1516 * we are expected to wait. Extra check required to make sure
1517 * we don't wait needlessly on the last iteration.
1518 */
1519 if (i - 1)
1520 udelay(1);
1521 }
1522
1523 return -EAGAIN;
1524}
1525EXPORT_SYMBOL_GPL(coresight_timeout);
1526
1527u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)
1528{
1529 return csdev_access_relaxed_read32(&csdev->access, offset);
1530}
1531
1532u32 coresight_read32(struct coresight_device *csdev, u32 offset)
1533{
1534 return csdev_access_read32(&csdev->access, offset);
1535}
1536
1537void coresight_relaxed_write32(struct coresight_device *csdev,
1538 u32 val, u32 offset)
1539{
1540 csdev_access_relaxed_write32(&csdev->access, val, offset);
1541}
1542
1543void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)
1544{
1545 csdev_access_write32(&csdev->access, val, offset);
1546}
1547
1548u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset)
1549{
1550 return csdev_access_relaxed_read64(&csdev->access, offset);
1551}
1552
1553u64 coresight_read64(struct coresight_device *csdev, u32 offset)
1554{
1555 return csdev_access_read64(&csdev->access, offset);
1556}
1557
1558void coresight_relaxed_write64(struct coresight_device *csdev,
1559 u64 val, u32 offset)
1560{
1561 csdev_access_relaxed_write64(&csdev->access, val, offset);
1562}
1563
1564void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
1565{
1566 csdev_access_write64(&csdev->access, val, offset);
1567}
1568
1569/*
1570 * coresight_release_platform_data: Release references to the devices connected
1571 * to the output port of this device.
1572 */
1573void coresight_release_platform_data(struct coresight_device *csdev,
1574 struct coresight_platform_data *pdata)
1575{
1576 int i;
1577 struct coresight_connection *conns = pdata->conns;
1578
1579 for (i = 0; i < pdata->nr_outport; i++) {
1580 /* If we have made the links, remove them now */
1581 if (csdev && conns[i].child_dev)
1582 coresight_remove_links(csdev, &conns[i]);
1583 /*
1584 * Drop the refcount and clear the handle as this device
1585 * is going away
1586 */
1587 if (conns[i].child_fwnode) {
1588 fwnode_handle_put(conns[i].child_fwnode);
1589 pdata->conns[i].child_fwnode = NULL;
1590 }
1591 }
1592 if (csdev)
1593 coresight_remove_conns_sysfs_group(csdev);
1594}
1595
1596struct coresight_device *coresight_register(struct coresight_desc *desc)
1597{
1598 int ret;
1599 int link_subtype;
1600 int nr_refcnts = 1;
1601 atomic_t *refcnts = NULL;
1602 struct coresight_device *csdev;
1603 bool registered = false;
1604
1605 csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
1606 if (!csdev) {
1607 ret = -ENOMEM;
1608 goto err_out;
1609 }
1610
1611 if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
1612 desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
1613 link_subtype = desc->subtype.link_subtype;
1614
1615 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
1616 nr_refcnts = desc->pdata->nr_inport;
1617 else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
1618 nr_refcnts = desc->pdata->nr_outport;
1619 }
1620
1621 refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
1622 if (!refcnts) {
1623 ret = -ENOMEM;
1624 kfree(csdev);
1625 goto err_out;
1626 }
1627
1628 csdev->refcnt = refcnts;
1629
1630 csdev->pdata = desc->pdata;
1631
1632 csdev->type = desc->type;
1633 csdev->subtype = desc->subtype;
1634 csdev->ops = desc->ops;
1635 csdev->access = desc->access;
1636 csdev->orphan = false;
1637
1638 csdev->dev.type = &coresight_dev_type[desc->type];
1639 csdev->dev.groups = desc->groups;
1640 csdev->dev.parent = desc->dev;
1641 csdev->dev.release = coresight_device_release;
1642 csdev->dev.bus = &coresight_bustype;
1643 /*
1644 * Hold the reference to our parent device. This will be
1645 * dropped only in coresight_device_release().
1646 */
1647 csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
1648 dev_set_name(&csdev->dev, "%s", desc->name);
1649
1650 /*
1651 * Make sure the device registration and the connection fixup
1652 * are synchronised, so that we don't see uninitialised devices
1653 * on the coresight bus while trying to resolve the connections.
1654 */
1655 mutex_lock(&coresight_mutex);
1656
1657 ret = device_register(&csdev->dev);
1658 if (ret) {
1659 put_device(&csdev->dev);
1660 /*
1661 * All resources are free'd explicitly via
1662 * coresight_device_release(), triggered from put_device().
1663 */
1664 goto out_unlock;
1665 }
1666
1667 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
1668 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
1669 ret = etm_perf_add_symlink_sink(csdev);
1670
1671 if (ret) {
1672 device_unregister(&csdev->dev);
1673 /*
1674 * As with the above, all resources are free'd
1675 * explicitly via coresight_device_release() triggered
1676 * from put_device(), which is in turn called from
1677 * function device_unregister().
1678 */
1679 goto out_unlock;
1680 }
1681 }
1682 /* Device is now registered */
1683 registered = true;
1684
1685 ret = coresight_create_conns_sysfs_group(csdev);
1686 if (!ret)
1687 ret = coresight_fixup_device_conns(csdev);
1688 if (!ret)
1689 ret = coresight_fixup_orphan_conns(csdev);
1690
1691out_unlock:
1692 mutex_unlock(&coresight_mutex);
1693 /* Success */
1694 if (!ret) {
1695 if (cti_assoc_ops && cti_assoc_ops->add)
1696 cti_assoc_ops->add(csdev);
1697 return csdev;
1698 }
1699
1700 /* Unregister the device if needed */
1701 if (registered) {
1702 coresight_unregister(csdev);
1703 return ERR_PTR(ret);
1704 }
1705
1706err_out:
1707 /* Cleanup the connection information */
1708 coresight_release_platform_data(NULL, desc->pdata);
1709 return ERR_PTR(ret);
1710}
1711EXPORT_SYMBOL_GPL(coresight_register);
1712
1713void coresight_unregister(struct coresight_device *csdev)
1714{
1715 etm_perf_del_symlink_sink(csdev);
1716 /* Remove references of that device in the topology */
1717 if (cti_assoc_ops && cti_assoc_ops->remove)
1718 cti_assoc_ops->remove(csdev);
1719 coresight_remove_conns(csdev);
1720 coresight_clear_default_sink(csdev);
1721 coresight_release_platform_data(csdev, csdev->pdata);
1722 device_unregister(&csdev->dev);
1723}
1724EXPORT_SYMBOL_GPL(coresight_unregister);
1725
1726
1727/*
1728 * coresight_search_device_idx - Search the fwnode handle of a device
1729 * in the given dev_idx list. Must be called with the coresight_mutex held.
1730 *
1731 * Returns the index of the entry, when found. Otherwise, -ENOENT.
1732 */
1733static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
1734 struct fwnode_handle *fwnode)
1735{
1736 int i;
1737
1738 for (i = 0; i < dict->nr_idx; i++)
1739 if (dict->fwnode_list[i] == fwnode)
1740 return i;
1741 return -ENOENT;
1742}
1743
1744bool coresight_loses_context_with_cpu(struct device *dev)
1745{
1746 return fwnode_property_present(dev_fwnode(dev),
1747 "arm,coresight-loses-context-with-cpu");
1748}
1749EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu);
1750
1751/*
1752 * coresight_alloc_device_name - Get an index for a given device in the
1753 * device index list specific to a driver. An index is allocated for a
1754 * device and is tracked with the fwnode_handle to prevent allocating
1755 * duplicate indices for the same device (e.g, if we defer probing of
1756 * a device due to dependencies), in case the index is requested again.
1757 */
1758char *coresight_alloc_device_name(struct coresight_dev_list *dict,
1759 struct device *dev)
1760{
1761 int idx;
1762 char *name = NULL;
1763 struct fwnode_handle **list;
1764
1765 mutex_lock(&coresight_mutex);
1766
1767 idx = coresight_search_device_idx(dict, dev_fwnode(dev));
1768 if (idx < 0) {
1769 /* Make space for the new entry */
1770 idx = dict->nr_idx;
1771 list = krealloc_array(dict->fwnode_list,
1772 idx + 1, sizeof(*dict->fwnode_list),
1773 GFP_KERNEL);
1774 if (ZERO_OR_NULL_PTR(list)) {
1775 idx = -ENOMEM;
1776 goto done;
1777 }
1778
1779 list[idx] = dev_fwnode(dev);
1780 dict->fwnode_list = list;
1781 dict->nr_idx = idx + 1;
1782 }
1783
1784 name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
1785done:
1786 mutex_unlock(&coresight_mutex);
1787 return name;
1788}
1789EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
1790
1791struct bus_type coresight_bustype = {
1792 .name = "coresight",
1793};
1794
1795static int __init coresight_init(void)
1796{
1797 int ret;
1798
1799 ret = bus_register(&coresight_bustype);
1800 if (ret)
1801 return ret;
1802
1803 ret = etm_perf_init();
1804 if (ret)
1805 goto exit_bus_unregister;
1806
1807 /* initialise the coresight syscfg API */
1808 ret = cscfg_init();
1809 if (!ret)
1810 return 0;
1811
1812 etm_perf_exit();
1813exit_bus_unregister:
1814 bus_unregister(&coresight_bustype);
1815 return ret;
1816}
1817
1818static void __exit coresight_exit(void)
1819{
1820 cscfg_exit();
1821 etm_perf_exit();
1822 bus_unregister(&coresight_bustype);
1823}
1824
1825module_init(coresight_init);
1826module_exit(coresight_exit);
1827
1828MODULE_LICENSE("GPL v2");
1829MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1830MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
1831MODULE_DESCRIPTION("Arm CoreSight tracer driver");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
4 */
5
6#include <linux/build_bug.h>
7#include <linux/kernel.h>
8#include <linux/init.h>
9#include <linux/types.h>
10#include <linux/device.h>
11#include <linux/io.h>
12#include <linux/idr.h>
13#include <linux/err.h>
14#include <linux/export.h>
15#include <linux/slab.h>
16#include <linux/stringhash.h>
17#include <linux/mutex.h>
18#include <linux/clk.h>
19#include <linux/coresight.h>
20#include <linux/property.h>
21#include <linux/delay.h>
22#include <linux/pm_runtime.h>
23
24#include "coresight-etm-perf.h"
25#include "coresight-priv.h"
26#include "coresight-syscfg.h"
27
28static DEFINE_MUTEX(coresight_mutex);
29static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);
30
31/*
32 * Use IDR to map the hash of the source's device name
33 * to the pointer of path for the source. The idr is for
34 * the sources which aren't associated with CPU.
35 */
36static DEFINE_IDR(path_idr);
37
38/**
39 * struct coresight_node - elements of a path, from source to sink
40 * @csdev: Address of an element.
41 * @link: hook to the list.
42 */
43struct coresight_node {
44 struct coresight_device *csdev;
45 struct list_head link;
46};
47
48/*
49 * When operating Coresight drivers from the sysFS interface, only a single
50 * path can exist from a tracer (associated to a CPU) to a sink.
51 */
52static DEFINE_PER_CPU(struct list_head *, tracer_path);
53
54/*
55 * When losing synchronisation a new barrier packet needs to be inserted at the
56 * beginning of the data collected in a buffer. That way the decoder knows that
57 * it needs to look for another sync sequence.
58 */
59const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
60EXPORT_SYMBOL_GPL(coresight_barrier_pkt);
61
62static const struct cti_assoc_op *cti_assoc_ops;
63
64ssize_t coresight_simple_show_pair(struct device *_dev,
65 struct device_attribute *attr, char *buf)
66{
67 struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
68 struct cs_pair_attribute *cs_attr = container_of(attr, struct cs_pair_attribute, attr);
69 u64 val;
70
71 pm_runtime_get_sync(_dev->parent);
72 val = csdev_access_relaxed_read_pair(&csdev->access, cs_attr->lo_off, cs_attr->hi_off);
73 pm_runtime_put_sync(_dev->parent);
74 return sysfs_emit(buf, "0x%llx\n", val);
75}
76EXPORT_SYMBOL_GPL(coresight_simple_show_pair);
77
78ssize_t coresight_simple_show32(struct device *_dev,
79 struct device_attribute *attr, char *buf)
80{
81 struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
82 struct cs_off_attribute *cs_attr = container_of(attr, struct cs_off_attribute, attr);
83 u64 val;
84
85 pm_runtime_get_sync(_dev->parent);
86 val = csdev_access_relaxed_read32(&csdev->access, cs_attr->off);
87 pm_runtime_put_sync(_dev->parent);
88 return sysfs_emit(buf, "0x%llx\n", val);
89}
90EXPORT_SYMBOL_GPL(coresight_simple_show32);
91
92void coresight_set_cti_ops(const struct cti_assoc_op *cti_op)
93{
94 cti_assoc_ops = cti_op;
95}
96EXPORT_SYMBOL_GPL(coresight_set_cti_ops);
97
98void coresight_remove_cti_ops(void)
99{
100 cti_assoc_ops = NULL;
101}
102EXPORT_SYMBOL_GPL(coresight_remove_cti_ops);
103
104void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev)
105{
106 per_cpu(csdev_sink, cpu) = csdev;
107}
108EXPORT_SYMBOL_GPL(coresight_set_percpu_sink);
109
110struct coresight_device *coresight_get_percpu_sink(int cpu)
111{
112 return per_cpu(csdev_sink, cpu);
113}
114EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);
115
116static struct coresight_connection *
117coresight_find_out_connection(struct coresight_device *src_dev,
118 struct coresight_device *dest_dev)
119{
120 int i;
121 struct coresight_connection *conn;
122
123 for (i = 0; i < src_dev->pdata->nr_outconns; i++) {
124 conn = src_dev->pdata->out_conns[i];
125 if (conn->dest_dev == dest_dev)
126 return conn;
127 }
128
129 dev_err(&src_dev->dev,
130 "couldn't find output connection, src_dev: %s, dest_dev: %s\n",
131 dev_name(&src_dev->dev), dev_name(&dest_dev->dev));
132
133 return ERR_PTR(-ENODEV);
134}
135
136static inline u32 coresight_read_claim_tags(struct coresight_device *csdev)
137{
138 return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR);
139}
140
141static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev)
142{
143 return coresight_read_claim_tags(csdev) == CORESIGHT_CLAIM_SELF_HOSTED;
144}
145
146static inline bool coresight_is_claimed_any(struct coresight_device *csdev)
147{
148 return coresight_read_claim_tags(csdev) != 0;
149}
150
151static inline void coresight_set_claim_tags(struct coresight_device *csdev)
152{
153 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
154 CORESIGHT_CLAIMSET);
155 isb();
156}
157
158static inline void coresight_clear_claim_tags(struct coresight_device *csdev)
159{
160 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
161 CORESIGHT_CLAIMCLR);
162 isb();
163}
164
165/*
166 * coresight_claim_device_unlocked : Claim the device for self-hosted usage
167 * to prevent an external tool from touching this device. As per PSCI
168 * standards, section "Preserving the execution context" => "Debug and Trace
169 * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and
170 * DBGCLAIM[0] is reserved for external tools.
171 *
172 * Called with CS_UNLOCKed for the component.
173 * Returns : 0 on success
174 */
175int coresight_claim_device_unlocked(struct coresight_device *csdev)
176{
177 if (WARN_ON(!csdev))
178 return -EINVAL;
179
180 if (coresight_is_claimed_any(csdev))
181 return -EBUSY;
182
183 coresight_set_claim_tags(csdev);
184 if (coresight_is_claimed_self_hosted(csdev))
185 return 0;
186 /* There was a race setting the tags, clean up and fail */
187 coresight_clear_claim_tags(csdev);
188 return -EBUSY;
189}
190EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);
191
192int coresight_claim_device(struct coresight_device *csdev)
193{
194 int rc;
195
196 if (WARN_ON(!csdev))
197 return -EINVAL;
198
199 CS_UNLOCK(csdev->access.base);
200 rc = coresight_claim_device_unlocked(csdev);
201 CS_LOCK(csdev->access.base);
202
203 return rc;
204}
205EXPORT_SYMBOL_GPL(coresight_claim_device);
206
207/*
208 * coresight_disclaim_device_unlocked : Clear the claim tags for the device.
209 * Called with CS_UNLOCKed for the component.
210 */
211void coresight_disclaim_device_unlocked(struct coresight_device *csdev)
212{
213
214 if (WARN_ON(!csdev))
215 return;
216
217 if (coresight_is_claimed_self_hosted(csdev))
218 coresight_clear_claim_tags(csdev);
219 else
220 /*
221 * The external agent may have not honoured our claim
222 * and has manipulated it. Or something else has seriously
223 * gone wrong in our driver.
224 */
225 WARN_ON_ONCE(1);
226}
227EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
228
229void coresight_disclaim_device(struct coresight_device *csdev)
230{
231 if (WARN_ON(!csdev))
232 return;
233
234 CS_UNLOCK(csdev->access.base);
235 coresight_disclaim_device_unlocked(csdev);
236 CS_LOCK(csdev->access.base);
237}
238EXPORT_SYMBOL_GPL(coresight_disclaim_device);
239
240/*
241 * Add a helper as an output device. This function takes the @coresight_mutex
242 * because it's assumed that it's called from the helper device, outside of the
243 * core code where the mutex would already be held. Don't add new calls to this
244 * from inside the core code, instead try to add the new helper to the DT and
245 * ACPI where it will be picked up and linked automatically.
246 */
247void coresight_add_helper(struct coresight_device *csdev,
248 struct coresight_device *helper)
249{
250 int i;
251 struct coresight_connection conn = {};
252 struct coresight_connection *new_conn;
253
254 mutex_lock(&coresight_mutex);
255 conn.dest_fwnode = fwnode_handle_get(dev_fwnode(&helper->dev));
256 conn.dest_dev = helper;
257 conn.dest_port = conn.src_port = -1;
258 conn.src_dev = csdev;
259
260 /*
261 * Check for duplicates because this is called every time a helper
262 * device is re-loaded. Existing connections will get re-linked
263 * automatically.
264 */
265 for (i = 0; i < csdev->pdata->nr_outconns; ++i)
266 if (csdev->pdata->out_conns[i]->dest_fwnode == conn.dest_fwnode)
267 goto unlock;
268
269 new_conn = coresight_add_out_conn(csdev->dev.parent, csdev->pdata,
270 &conn);
271 if (!IS_ERR(new_conn))
272 coresight_add_in_conn(new_conn);
273
274unlock:
275 mutex_unlock(&coresight_mutex);
276}
277EXPORT_SYMBOL_GPL(coresight_add_helper);
278
279static int coresight_enable_sink(struct coresight_device *csdev,
280 enum cs_mode mode, void *data)
281{
282 int ret;
283
284 /*
285 * We need to make sure the "new" session is compatible with the
286 * existing "mode" of operation.
287 */
288 if (!sink_ops(csdev)->enable)
289 return -EINVAL;
290
291 ret = sink_ops(csdev)->enable(csdev, mode, data);
292 if (ret)
293 return ret;
294
295 csdev->enable = true;
296
297 return 0;
298}
299
300static void coresight_disable_sink(struct coresight_device *csdev)
301{
302 int ret;
303
304 if (!sink_ops(csdev)->disable)
305 return;
306
307 ret = sink_ops(csdev)->disable(csdev);
308 if (ret)
309 return;
310 csdev->enable = false;
311}
312
313static int coresight_enable_link(struct coresight_device *csdev,
314 struct coresight_device *parent,
315 struct coresight_device *child)
316{
317 int ret = 0;
318 int link_subtype;
319 struct coresight_connection *inconn, *outconn;
320
321 if (!parent || !child)
322 return -EINVAL;
323
324 inconn = coresight_find_out_connection(parent, csdev);
325 outconn = coresight_find_out_connection(csdev, child);
326 link_subtype = csdev->subtype.link_subtype;
327
328 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && IS_ERR(inconn))
329 return PTR_ERR(inconn);
330 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && IS_ERR(outconn))
331 return PTR_ERR(outconn);
332
333 if (link_ops(csdev)->enable) {
334 ret = link_ops(csdev)->enable(csdev, inconn, outconn);
335 if (!ret)
336 csdev->enable = true;
337 }
338
339 return ret;
340}
341
342static void coresight_disable_link(struct coresight_device *csdev,
343 struct coresight_device *parent,
344 struct coresight_device *child)
345{
346 int i;
347 int link_subtype;
348 struct coresight_connection *inconn, *outconn;
349
350 if (!parent || !child)
351 return;
352
353 inconn = coresight_find_out_connection(parent, csdev);
354 outconn = coresight_find_out_connection(csdev, child);
355 link_subtype = csdev->subtype.link_subtype;
356
357 if (link_ops(csdev)->disable) {
358 link_ops(csdev)->disable(csdev, inconn, outconn);
359 }
360
361 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
362 for (i = 0; i < csdev->pdata->nr_inconns; i++)
363 if (atomic_read(&csdev->pdata->in_conns[i]->dest_refcnt) !=
364 0)
365 return;
366 } else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
367 for (i = 0; i < csdev->pdata->nr_outconns; i++)
368 if (atomic_read(&csdev->pdata->out_conns[i]->src_refcnt) !=
369 0)
370 return;
371 } else {
372 if (atomic_read(&csdev->refcnt) != 0)
373 return;
374 }
375
376 csdev->enable = false;
377}
378
379int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,
380 void *data)
381{
382 int ret;
383
384 if (!csdev->enable) {
385 if (source_ops(csdev)->enable) {
386 ret = source_ops(csdev)->enable(csdev, data, mode);
387 if (ret)
388 return ret;
389 }
390 csdev->enable = true;
391 }
392
393 atomic_inc(&csdev->refcnt);
394
395 return 0;
396}
397EXPORT_SYMBOL_GPL(coresight_enable_source);
398
399static bool coresight_is_helper(struct coresight_device *csdev)
400{
401 return csdev->type == CORESIGHT_DEV_TYPE_HELPER;
402}
403
404static int coresight_enable_helper(struct coresight_device *csdev,
405 enum cs_mode mode, void *data)
406{
407 int ret;
408
409 if (!helper_ops(csdev)->enable)
410 return 0;
411 ret = helper_ops(csdev)->enable(csdev, mode, data);
412 if (ret)
413 return ret;
414
415 csdev->enable = true;
416 return 0;
417}
418
419static void coresight_disable_helper(struct coresight_device *csdev)
420{
421 int ret;
422
423 if (!helper_ops(csdev)->disable)
424 return;
425
426 ret = helper_ops(csdev)->disable(csdev, NULL);
427 if (ret)
428 return;
429 csdev->enable = false;
430}
431
432static void coresight_disable_helpers(struct coresight_device *csdev)
433{
434 int i;
435 struct coresight_device *helper;
436
437 for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
438 helper = csdev->pdata->out_conns[i]->dest_dev;
439 if (helper && coresight_is_helper(helper))
440 coresight_disable_helper(helper);
441 }
442}
443
444/**
445 * coresight_disable_source - Drop the reference count by 1 and disable
446 * the device if there are no users left.
447 *
448 * @csdev: The coresight device to disable
449 * @data: Opaque data to pass on to the disable function of the source device.
450 * For example in perf mode this is a pointer to the struct perf_event.
451 *
452 * Returns true if the device has been disabled.
453 */
454bool coresight_disable_source(struct coresight_device *csdev, void *data)
455{
456 if (atomic_dec_return(&csdev->refcnt) == 0) {
457 if (source_ops(csdev)->disable)
458 source_ops(csdev)->disable(csdev, data);
459 coresight_disable_helpers(csdev);
460 csdev->enable = false;
461 }
462 return !csdev->enable;
463}
464EXPORT_SYMBOL_GPL(coresight_disable_source);
465
466/*
467 * coresight_disable_path_from : Disable components in the given path beyond
468 * @nd in the list. If @nd is NULL, all the components, except the SOURCE are
469 * disabled.
470 */
471static void coresight_disable_path_from(struct list_head *path,
472 struct coresight_node *nd)
473{
474 u32 type;
475 struct coresight_device *csdev, *parent, *child;
476
477 if (!nd)
478 nd = list_first_entry(path, struct coresight_node, link);
479
480 list_for_each_entry_continue(nd, path, link) {
481 csdev = nd->csdev;
482 type = csdev->type;
483
484 /*
485 * ETF devices are tricky... They can be a link or a sink,
486 * depending on how they are configured. If an ETF has been
487 * "activated" it will be configured as a sink, otherwise
488 * go ahead with the link configuration.
489 */
490 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
491 type = (csdev == coresight_get_sink(path)) ?
492 CORESIGHT_DEV_TYPE_SINK :
493 CORESIGHT_DEV_TYPE_LINK;
494
495 switch (type) {
496 case CORESIGHT_DEV_TYPE_SINK:
497 coresight_disable_sink(csdev);
498 break;
499 case CORESIGHT_DEV_TYPE_SOURCE:
500 /*
501 * We skip the first node in the path assuming that it
502 * is the source. So we don't expect a source device in
503 * the middle of a path.
504 */
505 WARN_ON(1);
506 break;
507 case CORESIGHT_DEV_TYPE_LINK:
508 parent = list_prev_entry(nd, link)->csdev;
509 child = list_next_entry(nd, link)->csdev;
510 coresight_disable_link(csdev, parent, child);
511 break;
512 default:
513 break;
514 }
515
516 /* Disable all helpers adjacent along the path last */
517 coresight_disable_helpers(csdev);
518 }
519}
520
521void coresight_disable_path(struct list_head *path)
522{
523 coresight_disable_path_from(path, NULL);
524}
525EXPORT_SYMBOL_GPL(coresight_disable_path);
526
527static int coresight_enable_helpers(struct coresight_device *csdev,
528 enum cs_mode mode, void *data)
529{
530 int i, ret = 0;
531 struct coresight_device *helper;
532
533 for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
534 helper = csdev->pdata->out_conns[i]->dest_dev;
535 if (!helper || !coresight_is_helper(helper))
536 continue;
537
538 ret = coresight_enable_helper(helper, mode, data);
539 if (ret)
540 return ret;
541 }
542
543 return 0;
544}
545
546int coresight_enable_path(struct list_head *path, enum cs_mode mode,
547 void *sink_data)
548{
549 int ret = 0;
550 u32 type;
551 struct coresight_node *nd;
552 struct coresight_device *csdev, *parent, *child;
553
554 list_for_each_entry_reverse(nd, path, link) {
555 csdev = nd->csdev;
556 type = csdev->type;
557
558 /* Enable all helpers adjacent to the path first */
559 ret = coresight_enable_helpers(csdev, mode, sink_data);
560 if (ret)
561 goto err;
562 /*
563 * ETF devices are tricky... They can be a link or a sink,
564 * depending on how they are configured. If an ETF has been
565 * "activated" it will be configured as a sink, otherwise
566 * go ahead with the link configuration.
567 */
568 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
569 type = (csdev == coresight_get_sink(path)) ?
570 CORESIGHT_DEV_TYPE_SINK :
571 CORESIGHT_DEV_TYPE_LINK;
572
573 switch (type) {
574 case CORESIGHT_DEV_TYPE_SINK:
575 ret = coresight_enable_sink(csdev, mode, sink_data);
576 /*
577 * Sink is the first component turned on. If we
578 * failed to enable the sink, there are no components
579 * that need disabling. Disabling the path here
580 * would mean we could disrupt an existing session.
581 */
582 if (ret)
583 goto out;
584 break;
585 case CORESIGHT_DEV_TYPE_SOURCE:
586 /* sources are enabled from either sysFS or Perf */
587 break;
588 case CORESIGHT_DEV_TYPE_LINK:
589 parent = list_prev_entry(nd, link)->csdev;
590 child = list_next_entry(nd, link)->csdev;
591 ret = coresight_enable_link(csdev, parent, child);
592 if (ret)
593 goto err;
594 break;
595 default:
596 goto err;
597 }
598 }
599
600out:
601 return ret;
602err:
603 coresight_disable_path_from(path, nd);
604 goto out;
605}
606
607struct coresight_device *coresight_get_sink(struct list_head *path)
608{
609 struct coresight_device *csdev;
610
611 if (!path)
612 return NULL;
613
614 csdev = list_last_entry(path, struct coresight_node, link)->csdev;
615 if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
616 csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
617 return NULL;
618
619 return csdev;
620}
621
622static struct coresight_device *
623coresight_find_enabled_sink(struct coresight_device *csdev)
624{
625 int i;
626 struct coresight_device *sink = NULL;
627
628 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
629 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
630 csdev->activated)
631 return csdev;
632
633 /*
634 * Recursively explore each port found on this element.
635 */
636 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
637 struct coresight_device *child_dev;
638
639 child_dev = csdev->pdata->out_conns[i]->dest_dev;
640 if (child_dev)
641 sink = coresight_find_enabled_sink(child_dev);
642 if (sink)
643 return sink;
644 }
645
646 return NULL;
647}
648
649/**
650 * coresight_get_enabled_sink - returns the first enabled sink using
651 * connection based search starting from the source reference
652 *
653 * @source: Coresight source device reference
654 */
655struct coresight_device *
656coresight_get_enabled_sink(struct coresight_device *source)
657{
658 if (!source)
659 return NULL;
660
661 return coresight_find_enabled_sink(source);
662}
663
664static int coresight_sink_by_id(struct device *dev, const void *data)
665{
666 struct coresight_device *csdev = to_coresight_device(dev);
667 unsigned long hash;
668
669 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
670 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
671
672 if (!csdev->ea)
673 return 0;
674 /*
675 * See function etm_perf_add_symlink_sink() to know where
676 * this comes from.
677 */
678 hash = (unsigned long)csdev->ea->var;
679
680 if ((u32)hash == *(u32 *)data)
681 return 1;
682 }
683
684 return 0;
685}
686
687/**
688 * coresight_get_sink_by_id - returns the sink that matches the id
689 * @id: Id of the sink to match
690 *
691 * The name of a sink is unique, whether it is found on the AMBA bus or
692 * otherwise. As such the hash of that name can easily be used to identify
693 * a sink.
694 */
695struct coresight_device *coresight_get_sink_by_id(u32 id)
696{
697 struct device *dev = NULL;
698
699 dev = bus_find_device(&coresight_bustype, NULL, &id,
700 coresight_sink_by_id);
701
702 return dev ? to_coresight_device(dev) : NULL;
703}
704
705/**
706 * coresight_get_ref- Helper function to increase reference count to module
707 * and device.
708 *
709 * @csdev: The coresight device to get a reference on.
710 *
711 * Return true in successful case and power up the device.
712 * Return false when failed to get reference of module.
713 */
714static inline bool coresight_get_ref(struct coresight_device *csdev)
715{
716 struct device *dev = csdev->dev.parent;
717
718 /* Make sure the driver can't be removed */
719 if (!try_module_get(dev->driver->owner))
720 return false;
721 /* Make sure the device can't go away */
722 get_device(dev);
723 pm_runtime_get_sync(dev);
724 return true;
725}
726
727/**
728 * coresight_put_ref- Helper function to decrease reference count to module
729 * and device. Power off the device.
730 *
731 * @csdev: The coresight device to decrement a reference from.
732 */
733static inline void coresight_put_ref(struct coresight_device *csdev)
734{
735 struct device *dev = csdev->dev.parent;
736
737 pm_runtime_put(dev);
738 put_device(dev);
739 module_put(dev->driver->owner);
740}
741
742/*
743 * coresight_grab_device - Power up this device and any of the helper
744 * devices connected to it for trace operation. Since the helper devices
745 * don't appear on the trace path, they should be handled along with the
746 * master device.
747 */
748static int coresight_grab_device(struct coresight_device *csdev)
749{
750 int i;
751
752 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
753 struct coresight_device *child;
754
755 child = csdev->pdata->out_conns[i]->dest_dev;
756 if (child && coresight_is_helper(child))
757 if (!coresight_get_ref(child))
758 goto err;
759 }
760 if (coresight_get_ref(csdev))
761 return 0;
762err:
763 for (i--; i >= 0; i--) {
764 struct coresight_device *child;
765
766 child = csdev->pdata->out_conns[i]->dest_dev;
767 if (child && coresight_is_helper(child))
768 coresight_put_ref(child);
769 }
770 return -ENODEV;
771}
772
773/*
774 * coresight_drop_device - Release this device and any of the helper
775 * devices connected to it.
776 */
777static void coresight_drop_device(struct coresight_device *csdev)
778{
779 int i;
780
781 coresight_put_ref(csdev);
782 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
783 struct coresight_device *child;
784
785 child = csdev->pdata->out_conns[i]->dest_dev;
786 if (child && coresight_is_helper(child))
787 coresight_put_ref(child);
788 }
789}
790
791/**
792 * _coresight_build_path - recursively build a path from a @csdev to a sink.
793 * @csdev: The device to start from.
794 * @sink: The final sink we want in this path.
795 * @path: The list to add devices to.
796 *
797 * The tree of Coresight device is traversed until an activated sink is
798 * found. From there the sink is added to the list along with all the
799 * devices that led to that point - the end result is a list from source
800 * to sink. In that list the source is the first device and the sink the
801 * last one.
802 */
803static int _coresight_build_path(struct coresight_device *csdev,
804 struct coresight_device *sink,
805 struct list_head *path)
806{
807 int i, ret;
808 bool found = false;
809 struct coresight_node *node;
810
811 /* An activated sink has been found. Enqueue the element */
812 if (csdev == sink)
813 goto out;
814
815 if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) &&
816 sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) {
817 if (_coresight_build_path(sink, sink, path) == 0) {
818 found = true;
819 goto out;
820 }
821 }
822
823 /* Not a sink - recursively explore each port found on this element */
824 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
825 struct coresight_device *child_dev;
826
827 child_dev = csdev->pdata->out_conns[i]->dest_dev;
828 if (child_dev &&
829 _coresight_build_path(child_dev, sink, path) == 0) {
830 found = true;
831 break;
832 }
833 }
834
835 if (!found)
836 return -ENODEV;
837
838out:
839 /*
840 * A path from this element to a sink has been found. The elements
841 * leading to the sink are already enqueued, all that is left to do
842 * is tell the PM runtime core we need this element and add a node
843 * for it.
844 */
845 ret = coresight_grab_device(csdev);
846 if (ret)
847 return ret;
848
849 node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
850 if (!node)
851 return -ENOMEM;
852
853 node->csdev = csdev;
854 list_add(&node->link, path);
855
856 return 0;
857}
858
859struct list_head *coresight_build_path(struct coresight_device *source,
860 struct coresight_device *sink)
861{
862 struct list_head *path;
863 int rc;
864
865 if (!sink)
866 return ERR_PTR(-EINVAL);
867
868 path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
869 if (!path)
870 return ERR_PTR(-ENOMEM);
871
872 INIT_LIST_HEAD(path);
873
874 rc = _coresight_build_path(source, sink, path);
875 if (rc) {
876 kfree(path);
877 return ERR_PTR(rc);
878 }
879
880 return path;
881}
882
883/**
884 * coresight_release_path - release a previously built path.
885 * @path: the path to release.
886 *
887 * Go through all the elements of a path and 1) removed it from the list and
888 * 2) free the memory allocated for each node.
889 */
890void coresight_release_path(struct list_head *path)
891{
892 struct coresight_device *csdev;
893 struct coresight_node *nd, *next;
894
895 list_for_each_entry_safe(nd, next, path, link) {
896 csdev = nd->csdev;
897
898 coresight_drop_device(csdev);
899 list_del(&nd->link);
900 kfree(nd);
901 }
902
903 kfree(path);
904}
905
906/* return true if the device is a suitable type for a default sink */
907static inline bool coresight_is_def_sink_type(struct coresight_device *csdev)
908{
909 /* sink & correct subtype */
910 if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
911 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) &&
912 (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER))
913 return true;
914 return false;
915}
916
917/**
918 * coresight_select_best_sink - return the best sink for use as default from
919 * the two provided.
920 *
921 * @sink: current best sink.
922 * @depth: search depth where current sink was found.
923 * @new_sink: new sink for comparison with current sink.
924 * @new_depth: search depth where new sink was found.
925 *
926 * Sinks prioritised according to coresight_dev_subtype_sink, with only
927 * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used.
928 *
929 * Where two sinks of equal priority are found, the sink closest to the
930 * source is used (smallest search depth).
931 *
932 * return @new_sink & update @depth if better than @sink, else return @sink.
933 */
934static struct coresight_device *
935coresight_select_best_sink(struct coresight_device *sink, int *depth,
936 struct coresight_device *new_sink, int new_depth)
937{
938 bool update = false;
939
940 if (!sink) {
941 /* first found at this level */
942 update = true;
943 } else if (new_sink->subtype.sink_subtype >
944 sink->subtype.sink_subtype) {
945 /* found better sink */
946 update = true;
947 } else if ((new_sink->subtype.sink_subtype ==
948 sink->subtype.sink_subtype) &&
949 (*depth > new_depth)) {
950 /* found same but closer sink */
951 update = true;
952 }
953
954 if (update)
955 *depth = new_depth;
956 return update ? new_sink : sink;
957}
958
959/**
960 * coresight_find_sink - recursive function to walk trace connections from
961 * source to find a suitable default sink.
962 *
963 * @csdev: source / current device to check.
964 * @depth: [in] search depth of calling dev, [out] depth of found sink.
965 *
966 * This will walk the connection path from a source (ETM) till a suitable
967 * sink is encountered and return that sink to the original caller.
968 *
969 * If current device is a plain sink return that & depth, otherwise recursively
970 * call child connections looking for a sink. Select best possible using
971 * coresight_select_best_sink.
972 *
973 * return best sink found, or NULL if not found at this node or child nodes.
974 */
975static struct coresight_device *
976coresight_find_sink(struct coresight_device *csdev, int *depth)
977{
978 int i, curr_depth = *depth + 1, found_depth = 0;
979 struct coresight_device *found_sink = NULL;
980
981 if (coresight_is_def_sink_type(csdev)) {
982 found_depth = curr_depth;
983 found_sink = csdev;
984 if (csdev->type == CORESIGHT_DEV_TYPE_SINK)
985 goto return_def_sink;
986 /* look past LINKSINK for something better */
987 }
988
989 /*
990 * Not a sink we want - or possible child sink may be better.
991 * recursively explore each port found on this element.
992 */
993 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
994 struct coresight_device *child_dev, *sink = NULL;
995 int child_depth = curr_depth;
996
997 child_dev = csdev->pdata->out_conns[i]->dest_dev;
998 if (child_dev)
999 sink = coresight_find_sink(child_dev, &child_depth);
1000
1001 if (sink)
1002 found_sink = coresight_select_best_sink(found_sink,
1003 &found_depth,
1004 sink,
1005 child_depth);
1006 }
1007
1008return_def_sink:
1009 /* return found sink and depth */
1010 if (found_sink)
1011 *depth = found_depth;
1012 return found_sink;
1013}
1014
1015/**
1016 * coresight_find_default_sink: Find a sink suitable for use as a
1017 * default sink.
1018 *
1019 * @csdev: starting source to find a connected sink.
1020 *
1021 * Walks connections graph looking for a suitable sink to enable for the
1022 * supplied source. Uses CoreSight device subtypes and distance from source
1023 * to select the best sink.
1024 *
1025 * If a sink is found, then the default sink for this device is set and
1026 * will be automatically used in future.
1027 *
1028 * Used in cases where the CoreSight user (perf / sysfs) has not selected a
1029 * sink.
1030 */
1031struct coresight_device *
1032coresight_find_default_sink(struct coresight_device *csdev)
1033{
1034 int depth = 0;
1035
1036 /* look for a default sink if we have not found for this device */
1037 if (!csdev->def_sink) {
1038 if (coresight_is_percpu_source(csdev))
1039 csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev));
1040 if (!csdev->def_sink)
1041 csdev->def_sink = coresight_find_sink(csdev, &depth);
1042 }
1043 return csdev->def_sink;
1044}
1045
1046static int coresight_remove_sink_ref(struct device *dev, void *data)
1047{
1048 struct coresight_device *sink = data;
1049 struct coresight_device *source = to_coresight_device(dev);
1050
1051 if (source->def_sink == sink)
1052 source->def_sink = NULL;
1053 return 0;
1054}
1055
1056/**
1057 * coresight_clear_default_sink: Remove all default sink references to the
1058 * supplied sink.
1059 *
1060 * If supplied device is a sink, then check all the bus devices and clear
1061 * out all the references to this sink from the coresight_device def_sink
1062 * parameter.
1063 *
1064 * @csdev: coresight sink - remove references to this from all sources.
1065 */
1066static void coresight_clear_default_sink(struct coresight_device *csdev)
1067{
1068 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
1069 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) {
1070 bus_for_each_dev(&coresight_bustype, NULL, csdev,
1071 coresight_remove_sink_ref);
1072 }
1073}
1074
1075/** coresight_validate_source - make sure a source has the right credentials
1076 * @csdev: the device structure for a source.
1077 * @function: the function this was called from.
1078 *
1079 * Assumes the coresight_mutex is held.
1080 */
1081static int coresight_validate_source(struct coresight_device *csdev,
1082 const char *function)
1083{
1084 u32 type, subtype;
1085
1086 type = csdev->type;
1087 subtype = csdev->subtype.source_subtype;
1088
1089 if (type != CORESIGHT_DEV_TYPE_SOURCE) {
1090 dev_err(&csdev->dev, "wrong device type in %s\n", function);
1091 return -EINVAL;
1092 }
1093
1094 if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
1095 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE &&
1096 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM &&
1097 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS) {
1098 dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
1099 return -EINVAL;
1100 }
1101
1102 return 0;
1103}
1104
1105int coresight_enable(struct coresight_device *csdev)
1106{
1107 int cpu, ret = 0;
1108 struct coresight_device *sink;
1109 struct list_head *path;
1110 enum coresight_dev_subtype_source subtype;
1111 u32 hash;
1112
1113 subtype = csdev->subtype.source_subtype;
1114
1115 mutex_lock(&coresight_mutex);
1116
1117 ret = coresight_validate_source(csdev, __func__);
1118 if (ret)
1119 goto out;
1120
1121 if (csdev->enable) {
1122 /*
1123 * There could be multiple applications driving the software
1124 * source. So keep the refcount for each such user when the
1125 * source is already enabled.
1126 */
1127 if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
1128 atomic_inc(&csdev->refcnt);
1129 goto out;
1130 }
1131
1132 sink = coresight_get_enabled_sink(csdev);
1133 if (!sink) {
1134 ret = -EINVAL;
1135 goto out;
1136 }
1137
1138 path = coresight_build_path(csdev, sink);
1139 if (IS_ERR(path)) {
1140 pr_err("building path(s) failed\n");
1141 ret = PTR_ERR(path);
1142 goto out;
1143 }
1144
1145 ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
1146 if (ret)
1147 goto err_path;
1148
1149 ret = coresight_enable_source(csdev, CS_MODE_SYSFS, NULL);
1150 if (ret)
1151 goto err_source;
1152
1153 switch (subtype) {
1154 case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
1155 /*
1156 * When working from sysFS it is important to keep track
1157 * of the paths that were created so that they can be
1158 * undone in 'coresight_disable()'. Since there can only
1159 * be a single session per tracer (when working from sysFS)
1160 * a per-cpu variable will do just fine.
1161 */
1162 cpu = source_ops(csdev)->cpu_id(csdev);
1163 per_cpu(tracer_path, cpu) = path;
1164 break;
1165 case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
1166 case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
1167 case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
1168 /*
1169 * Use the hash of source's device name as ID
1170 * and map the ID to the pointer of the path.
1171 */
1172 hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
1173 ret = idr_alloc_u32(&path_idr, path, &hash, hash, GFP_KERNEL);
1174 if (ret)
1175 goto err_source;
1176 break;
1177 default:
1178 /* We can't be here */
1179 break;
1180 }
1181
1182out:
1183 mutex_unlock(&coresight_mutex);
1184 return ret;
1185
1186err_source:
1187 coresight_disable_path(path);
1188
1189err_path:
1190 coresight_release_path(path);
1191 goto out;
1192}
1193EXPORT_SYMBOL_GPL(coresight_enable);
1194
1195void coresight_disable(struct coresight_device *csdev)
1196{
1197 int cpu, ret;
1198 struct list_head *path = NULL;
1199 u32 hash;
1200
1201 mutex_lock(&coresight_mutex);
1202
1203 ret = coresight_validate_source(csdev, __func__);
1204 if (ret)
1205 goto out;
1206
1207 if (!csdev->enable || !coresight_disable_source(csdev, NULL))
1208 goto out;
1209
1210 switch (csdev->subtype.source_subtype) {
1211 case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
1212 cpu = source_ops(csdev)->cpu_id(csdev);
1213 path = per_cpu(tracer_path, cpu);
1214 per_cpu(tracer_path, cpu) = NULL;
1215 break;
1216 case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
1217 case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
1218 case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
1219 hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
1220 /* Find the path by the hash. */
1221 path = idr_find(&path_idr, hash);
1222 if (path == NULL) {
1223 pr_err("Path is not found for %s\n", dev_name(&csdev->dev));
1224 goto out;
1225 }
1226 idr_remove(&path_idr, hash);
1227 break;
1228 default:
1229 /* We can't be here */
1230 break;
1231 }
1232
1233 coresight_disable_path(path);
1234 coresight_release_path(path);
1235
1236out:
1237 mutex_unlock(&coresight_mutex);
1238}
1239EXPORT_SYMBOL_GPL(coresight_disable);
1240
1241static ssize_t enable_sink_show(struct device *dev,
1242 struct device_attribute *attr, char *buf)
1243{
1244 struct coresight_device *csdev = to_coresight_device(dev);
1245
1246 return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
1247}
1248
1249static ssize_t enable_sink_store(struct device *dev,
1250 struct device_attribute *attr,
1251 const char *buf, size_t size)
1252{
1253 int ret;
1254 unsigned long val;
1255 struct coresight_device *csdev = to_coresight_device(dev);
1256
1257 ret = kstrtoul(buf, 10, &val);
1258 if (ret)
1259 return ret;
1260
1261 if (val)
1262 csdev->activated = true;
1263 else
1264 csdev->activated = false;
1265
1266 return size;
1267
1268}
1269static DEVICE_ATTR_RW(enable_sink);
1270
1271static ssize_t enable_source_show(struct device *dev,
1272 struct device_attribute *attr, char *buf)
1273{
1274 struct coresight_device *csdev = to_coresight_device(dev);
1275
1276 return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
1277}
1278
1279static ssize_t enable_source_store(struct device *dev,
1280 struct device_attribute *attr,
1281 const char *buf, size_t size)
1282{
1283 int ret = 0;
1284 unsigned long val;
1285 struct coresight_device *csdev = to_coresight_device(dev);
1286
1287 ret = kstrtoul(buf, 10, &val);
1288 if (ret)
1289 return ret;
1290
1291 if (val) {
1292 ret = coresight_enable(csdev);
1293 if (ret)
1294 return ret;
1295 } else {
1296 coresight_disable(csdev);
1297 }
1298
1299 return size;
1300}
1301static DEVICE_ATTR_RW(enable_source);
1302
1303static struct attribute *coresight_sink_attrs[] = {
1304 &dev_attr_enable_sink.attr,
1305 NULL,
1306};
1307ATTRIBUTE_GROUPS(coresight_sink);
1308
1309static struct attribute *coresight_source_attrs[] = {
1310 &dev_attr_enable_source.attr,
1311 NULL,
1312};
1313ATTRIBUTE_GROUPS(coresight_source);
1314
1315static struct device_type coresight_dev_type[] = {
1316 {
1317 .name = "sink",
1318 .groups = coresight_sink_groups,
1319 },
1320 {
1321 .name = "link",
1322 },
1323 {
1324 .name = "linksink",
1325 .groups = coresight_sink_groups,
1326 },
1327 {
1328 .name = "source",
1329 .groups = coresight_source_groups,
1330 },
1331 {
1332 .name = "helper",
1333 }
1334};
1335/* Ensure the enum matches the names and groups */
1336static_assert(ARRAY_SIZE(coresight_dev_type) == CORESIGHT_DEV_TYPE_MAX);
1337
1338static void coresight_device_release(struct device *dev)
1339{
1340 struct coresight_device *csdev = to_coresight_device(dev);
1341
1342 fwnode_handle_put(csdev->dev.fwnode);
1343 kfree(csdev);
1344}
1345
1346static int coresight_orphan_match(struct device *dev, void *data)
1347{
1348 int i, ret = 0;
1349 bool still_orphan = false;
1350 struct coresight_device *dst_csdev = data;
1351 struct coresight_device *src_csdev = to_coresight_device(dev);
1352 struct coresight_connection *conn;
1353 bool fixup_self = (src_csdev == dst_csdev);
1354
1355 /* Move on to another component if no connection is orphan */
1356 if (!src_csdev->orphan)
1357 return 0;
1358 /*
1359 * Circle through all the connections of that component. If we find
1360 * an orphan connection whose name matches @dst_csdev, link it.
1361 */
1362 for (i = 0; i < src_csdev->pdata->nr_outconns; i++) {
1363 conn = src_csdev->pdata->out_conns[i];
1364
1365 /* Skip the port if it's already connected. */
1366 if (conn->dest_dev)
1367 continue;
1368
1369 /*
1370 * If we are at the "new" device, which triggered this search,
1371 * we must find the remote device from the fwnode in the
1372 * connection.
1373 */
1374 if (fixup_self)
1375 dst_csdev = coresight_find_csdev_by_fwnode(
1376 conn->dest_fwnode);
1377
1378 /* Does it match this newly added device? */
1379 if (dst_csdev && conn->dest_fwnode == dst_csdev->dev.fwnode) {
1380 ret = coresight_make_links(src_csdev, conn, dst_csdev);
1381 if (ret)
1382 return ret;
1383
1384 /*
1385 * Install the device connection. This also indicates that
1386 * the links are operational on both ends.
1387 */
1388 conn->dest_dev = dst_csdev;
1389 conn->src_dev = src_csdev;
1390
1391 ret = coresight_add_in_conn(conn);
1392 if (ret)
1393 return ret;
1394 } else {
1395 /* This component still has an orphan */
1396 still_orphan = true;
1397 }
1398 }
1399
1400 src_csdev->orphan = still_orphan;
1401
1402 /*
1403 * Returning '0' in case we didn't encounter any error,
1404 * ensures that all known component on the bus will be checked.
1405 */
1406 return 0;
1407}
1408
1409static int coresight_fixup_orphan_conns(struct coresight_device *csdev)
1410{
1411 return bus_for_each_dev(&coresight_bustype, NULL,
1412 csdev, coresight_orphan_match);
1413}
1414
1415/* coresight_remove_conns - Remove other device's references to this device */
1416static void coresight_remove_conns(struct coresight_device *csdev)
1417{
1418 int i, j;
1419 struct coresight_connection *conn;
1420
1421 /*
1422 * Remove the input connection references from the destination device
1423 * for each output connection.
1424 */
1425 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
1426 conn = csdev->pdata->out_conns[i];
1427 if (!conn->dest_dev)
1428 continue;
1429
1430 for (j = 0; j < conn->dest_dev->pdata->nr_inconns; ++j)
1431 if (conn->dest_dev->pdata->in_conns[j] == conn) {
1432 conn->dest_dev->pdata->in_conns[j] = NULL;
1433 break;
1434 }
1435 }
1436
1437 /*
1438 * For all input connections, remove references to this device.
1439 * Connection objects are shared so modifying this device's input
1440 * connections affects the other device's output connection.
1441 */
1442 for (i = 0; i < csdev->pdata->nr_inconns; ++i) {
1443 conn = csdev->pdata->in_conns[i];
1444 /* Input conns array is sparse */
1445 if (!conn)
1446 continue;
1447
1448 conn->src_dev->orphan = true;
1449 coresight_remove_links(conn->src_dev, conn);
1450 conn->dest_dev = NULL;
1451 }
1452}
1453
1454/**
1455 * coresight_timeout - loop until a bit has changed to a specific register
1456 * state.
1457 * @csa: coresight device access for the device
1458 * @offset: Offset of the register from the base of the device.
1459 * @position: the position of the bit of interest.
1460 * @value: the value the bit should have.
1461 *
1462 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
1463 * TIMEOUT_US has elapsed, which ever happens first.
1464 */
1465int coresight_timeout(struct csdev_access *csa, u32 offset,
1466 int position, int value)
1467{
1468 int i;
1469 u32 val;
1470
1471 for (i = TIMEOUT_US; i > 0; i--) {
1472 val = csdev_access_read32(csa, offset);
1473 /* waiting on the bit to go from 0 to 1 */
1474 if (value) {
1475 if (val & BIT(position))
1476 return 0;
1477 /* waiting on the bit to go from 1 to 0 */
1478 } else {
1479 if (!(val & BIT(position)))
1480 return 0;
1481 }
1482
1483 /*
1484 * Delay is arbitrary - the specification doesn't say how long
1485 * we are expected to wait. Extra check required to make sure
1486 * we don't wait needlessly on the last iteration.
1487 */
1488 if (i - 1)
1489 udelay(1);
1490 }
1491
1492 return -EAGAIN;
1493}
1494EXPORT_SYMBOL_GPL(coresight_timeout);
1495
1496u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)
1497{
1498 return csdev_access_relaxed_read32(&csdev->access, offset);
1499}
1500
1501u32 coresight_read32(struct coresight_device *csdev, u32 offset)
1502{
1503 return csdev_access_read32(&csdev->access, offset);
1504}
1505
1506void coresight_relaxed_write32(struct coresight_device *csdev,
1507 u32 val, u32 offset)
1508{
1509 csdev_access_relaxed_write32(&csdev->access, val, offset);
1510}
1511
1512void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)
1513{
1514 csdev_access_write32(&csdev->access, val, offset);
1515}
1516
1517u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset)
1518{
1519 return csdev_access_relaxed_read64(&csdev->access, offset);
1520}
1521
1522u64 coresight_read64(struct coresight_device *csdev, u32 offset)
1523{
1524 return csdev_access_read64(&csdev->access, offset);
1525}
1526
1527void coresight_relaxed_write64(struct coresight_device *csdev,
1528 u64 val, u32 offset)
1529{
1530 csdev_access_relaxed_write64(&csdev->access, val, offset);
1531}
1532
1533void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
1534{
1535 csdev_access_write64(&csdev->access, val, offset);
1536}
1537
1538/*
1539 * coresight_release_platform_data: Release references to the devices connected
1540 * to the output port of this device.
1541 */
1542void coresight_release_platform_data(struct coresight_device *csdev,
1543 struct device *dev,
1544 struct coresight_platform_data *pdata)
1545{
1546 int i;
1547 struct coresight_connection **conns = pdata->out_conns;
1548
1549 for (i = 0; i < pdata->nr_outconns; i++) {
1550 /* If we have made the links, remove them now */
1551 if (csdev && conns[i]->dest_dev)
1552 coresight_remove_links(csdev, conns[i]);
1553 /*
1554 * Drop the refcount and clear the handle as this device
1555 * is going away
1556 */
1557 fwnode_handle_put(conns[i]->dest_fwnode);
1558 conns[i]->dest_fwnode = NULL;
1559 devm_kfree(dev, conns[i]);
1560 }
1561 devm_kfree(dev, pdata->out_conns);
1562 devm_kfree(dev, pdata->in_conns);
1563 devm_kfree(dev, pdata);
1564 if (csdev)
1565 coresight_remove_conns_sysfs_group(csdev);
1566}
1567
1568struct coresight_device *coresight_register(struct coresight_desc *desc)
1569{
1570 int ret;
1571 struct coresight_device *csdev;
1572 bool registered = false;
1573
1574 csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
1575 if (!csdev) {
1576 ret = -ENOMEM;
1577 goto err_out;
1578 }
1579
1580 csdev->pdata = desc->pdata;
1581
1582 csdev->type = desc->type;
1583 csdev->subtype = desc->subtype;
1584 csdev->ops = desc->ops;
1585 csdev->access = desc->access;
1586 csdev->orphan = true;
1587
1588 csdev->dev.type = &coresight_dev_type[desc->type];
1589 csdev->dev.groups = desc->groups;
1590 csdev->dev.parent = desc->dev;
1591 csdev->dev.release = coresight_device_release;
1592 csdev->dev.bus = &coresight_bustype;
1593 /*
1594 * Hold the reference to our parent device. This will be
1595 * dropped only in coresight_device_release().
1596 */
1597 csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
1598 dev_set_name(&csdev->dev, "%s", desc->name);
1599
1600 /*
1601 * Make sure the device registration and the connection fixup
1602 * are synchronised, so that we don't see uninitialised devices
1603 * on the coresight bus while trying to resolve the connections.
1604 */
1605 mutex_lock(&coresight_mutex);
1606
1607 ret = device_register(&csdev->dev);
1608 if (ret) {
1609 put_device(&csdev->dev);
1610 /*
1611 * All resources are free'd explicitly via
1612 * coresight_device_release(), triggered from put_device().
1613 */
1614 goto out_unlock;
1615 }
1616
1617 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
1618 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
1619 ret = etm_perf_add_symlink_sink(csdev);
1620
1621 if (ret) {
1622 device_unregister(&csdev->dev);
1623 /*
1624 * As with the above, all resources are free'd
1625 * explicitly via coresight_device_release() triggered
1626 * from put_device(), which is in turn called from
1627 * function device_unregister().
1628 */
1629 goto out_unlock;
1630 }
1631 }
1632 /* Device is now registered */
1633 registered = true;
1634
1635 ret = coresight_create_conns_sysfs_group(csdev);
1636 if (!ret)
1637 ret = coresight_fixup_orphan_conns(csdev);
1638
1639out_unlock:
1640 mutex_unlock(&coresight_mutex);
1641 /* Success */
1642 if (!ret) {
1643 if (cti_assoc_ops && cti_assoc_ops->add)
1644 cti_assoc_ops->add(csdev);
1645 return csdev;
1646 }
1647
1648 /* Unregister the device if needed */
1649 if (registered) {
1650 coresight_unregister(csdev);
1651 return ERR_PTR(ret);
1652 }
1653
1654err_out:
1655 /* Cleanup the connection information */
1656 coresight_release_platform_data(NULL, desc->dev, desc->pdata);
1657 return ERR_PTR(ret);
1658}
1659EXPORT_SYMBOL_GPL(coresight_register);
1660
1661void coresight_unregister(struct coresight_device *csdev)
1662{
1663 etm_perf_del_symlink_sink(csdev);
1664 /* Remove references of that device in the topology */
1665 if (cti_assoc_ops && cti_assoc_ops->remove)
1666 cti_assoc_ops->remove(csdev);
1667 coresight_remove_conns(csdev);
1668 coresight_clear_default_sink(csdev);
1669 coresight_release_platform_data(csdev, csdev->dev.parent, csdev->pdata);
1670 device_unregister(&csdev->dev);
1671}
1672EXPORT_SYMBOL_GPL(coresight_unregister);
1673
1674
1675/*
1676 * coresight_search_device_idx - Search the fwnode handle of a device
1677 * in the given dev_idx list. Must be called with the coresight_mutex held.
1678 *
1679 * Returns the index of the entry, when found. Otherwise, -ENOENT.
1680 */
1681static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
1682 struct fwnode_handle *fwnode)
1683{
1684 int i;
1685
1686 for (i = 0; i < dict->nr_idx; i++)
1687 if (dict->fwnode_list[i] == fwnode)
1688 return i;
1689 return -ENOENT;
1690}
1691
1692static bool coresight_compare_type(enum coresight_dev_type type_a,
1693 union coresight_dev_subtype subtype_a,
1694 enum coresight_dev_type type_b,
1695 union coresight_dev_subtype subtype_b)
1696{
1697 if (type_a != type_b)
1698 return false;
1699
1700 switch (type_a) {
1701 case CORESIGHT_DEV_TYPE_SINK:
1702 return subtype_a.sink_subtype == subtype_b.sink_subtype;
1703 case CORESIGHT_DEV_TYPE_LINK:
1704 return subtype_a.link_subtype == subtype_b.link_subtype;
1705 case CORESIGHT_DEV_TYPE_LINKSINK:
1706 return subtype_a.link_subtype == subtype_b.link_subtype &&
1707 subtype_a.sink_subtype == subtype_b.sink_subtype;
1708 case CORESIGHT_DEV_TYPE_SOURCE:
1709 return subtype_a.source_subtype == subtype_b.source_subtype;
1710 case CORESIGHT_DEV_TYPE_HELPER:
1711 return subtype_a.helper_subtype == subtype_b.helper_subtype;
1712 default:
1713 return false;
1714 }
1715}
1716
1717struct coresight_device *
1718coresight_find_input_type(struct coresight_platform_data *pdata,
1719 enum coresight_dev_type type,
1720 union coresight_dev_subtype subtype)
1721{
1722 int i;
1723 struct coresight_connection *conn;
1724
1725 for (i = 0; i < pdata->nr_inconns; ++i) {
1726 conn = pdata->in_conns[i];
1727 if (conn &&
1728 coresight_compare_type(type, subtype, conn->src_dev->type,
1729 conn->src_dev->subtype))
1730 return conn->src_dev;
1731 }
1732 return NULL;
1733}
1734EXPORT_SYMBOL_GPL(coresight_find_input_type);
1735
1736struct coresight_device *
1737coresight_find_output_type(struct coresight_platform_data *pdata,
1738 enum coresight_dev_type type,
1739 union coresight_dev_subtype subtype)
1740{
1741 int i;
1742 struct coresight_connection *conn;
1743
1744 for (i = 0; i < pdata->nr_outconns; ++i) {
1745 conn = pdata->out_conns[i];
1746 if (conn->dest_dev &&
1747 coresight_compare_type(type, subtype, conn->dest_dev->type,
1748 conn->dest_dev->subtype))
1749 return conn->dest_dev;
1750 }
1751 return NULL;
1752}
1753EXPORT_SYMBOL_GPL(coresight_find_output_type);
1754
1755bool coresight_loses_context_with_cpu(struct device *dev)
1756{
1757 return fwnode_property_present(dev_fwnode(dev),
1758 "arm,coresight-loses-context-with-cpu");
1759}
1760EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu);
1761
1762/*
1763 * coresight_alloc_device_name - Get an index for a given device in the
1764 * device index list specific to a driver. An index is allocated for a
1765 * device and is tracked with the fwnode_handle to prevent allocating
1766 * duplicate indices for the same device (e.g, if we defer probing of
1767 * a device due to dependencies), in case the index is requested again.
1768 */
1769char *coresight_alloc_device_name(struct coresight_dev_list *dict,
1770 struct device *dev)
1771{
1772 int idx;
1773 char *name = NULL;
1774 struct fwnode_handle **list;
1775
1776 mutex_lock(&coresight_mutex);
1777
1778 idx = coresight_search_device_idx(dict, dev_fwnode(dev));
1779 if (idx < 0) {
1780 /* Make space for the new entry */
1781 idx = dict->nr_idx;
1782 list = krealloc_array(dict->fwnode_list,
1783 idx + 1, sizeof(*dict->fwnode_list),
1784 GFP_KERNEL);
1785 if (ZERO_OR_NULL_PTR(list)) {
1786 idx = -ENOMEM;
1787 goto done;
1788 }
1789
1790 list[idx] = dev_fwnode(dev);
1791 dict->fwnode_list = list;
1792 dict->nr_idx = idx + 1;
1793 }
1794
1795 name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
1796done:
1797 mutex_unlock(&coresight_mutex);
1798 return name;
1799}
1800EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
1801
1802struct bus_type coresight_bustype = {
1803 .name = "coresight",
1804};
1805
1806static int __init coresight_init(void)
1807{
1808 int ret;
1809
1810 ret = bus_register(&coresight_bustype);
1811 if (ret)
1812 return ret;
1813
1814 ret = etm_perf_init();
1815 if (ret)
1816 goto exit_bus_unregister;
1817
1818 /* initialise the coresight syscfg API */
1819 ret = cscfg_init();
1820 if (!ret)
1821 return 0;
1822
1823 etm_perf_exit();
1824exit_bus_unregister:
1825 bus_unregister(&coresight_bustype);
1826 return ret;
1827}
1828
1829static void __exit coresight_exit(void)
1830{
1831 cscfg_exit();
1832 etm_perf_exit();
1833 bus_unregister(&coresight_bustype);
1834}
1835
1836module_init(coresight_init);
1837module_exit(coresight_exit);
1838
1839MODULE_LICENSE("GPL v2");
1840MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1841MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
1842MODULE_DESCRIPTION("Arm CoreSight tracer driver");