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