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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/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/err.h>
13#include <linux/export.h>
14#include <linux/slab.h>
15#include <linux/stringhash.h>
16#include <linux/mutex.h>
17#include <linux/clk.h>
18#include <linux/coresight.h>
19#include <linux/property.h>
20#include <linux/delay.h>
21#include <linux/pm_runtime.h>
22
23#include "coresight-etm-perf.h"
24#include "coresight-priv.h"
25#include "coresight-syscfg.h"
26
27/*
28 * Mutex used to lock all sysfs enable and disable actions and loading and
29 * unloading devices by the Coresight core.
30 */
31DEFINE_MUTEX(coresight_mutex);
32static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);
33
34/**
35 * struct coresight_node - elements of a path, from source to sink
36 * @csdev: Address of an element.
37 * @link: hook to the list.
38 */
39struct coresight_node {
40 struct coresight_device *csdev;
41 struct list_head link;
42};
43
44/*
45 * When losing synchronisation a new barrier packet needs to be inserted at the
46 * beginning of the data collected in a buffer. That way the decoder knows that
47 * it needs to look for another sync sequence.
48 */
49const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
50EXPORT_SYMBOL_GPL(coresight_barrier_pkt);
51
52static const struct cti_assoc_op *cti_assoc_ops;
53
54void coresight_set_cti_ops(const struct cti_assoc_op *cti_op)
55{
56 cti_assoc_ops = cti_op;
57}
58EXPORT_SYMBOL_GPL(coresight_set_cti_ops);
59
60void coresight_remove_cti_ops(void)
61{
62 cti_assoc_ops = NULL;
63}
64EXPORT_SYMBOL_GPL(coresight_remove_cti_ops);
65
66void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev)
67{
68 per_cpu(csdev_sink, cpu) = csdev;
69}
70EXPORT_SYMBOL_GPL(coresight_set_percpu_sink);
71
72struct coresight_device *coresight_get_percpu_sink(int cpu)
73{
74 return per_cpu(csdev_sink, cpu);
75}
76EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);
77
78static struct coresight_connection *
79coresight_find_out_connection(struct coresight_device *src_dev,
80 struct coresight_device *dest_dev)
81{
82 int i;
83 struct coresight_connection *conn;
84
85 for (i = 0; i < src_dev->pdata->nr_outconns; i++) {
86 conn = src_dev->pdata->out_conns[i];
87 if (conn->dest_dev == dest_dev)
88 return conn;
89 }
90
91 dev_err(&src_dev->dev,
92 "couldn't find output connection, src_dev: %s, dest_dev: %s\n",
93 dev_name(&src_dev->dev), dev_name(&dest_dev->dev));
94
95 return ERR_PTR(-ENODEV);
96}
97
98static inline u32 coresight_read_claim_tags(struct coresight_device *csdev)
99{
100 return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR);
101}
102
103static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev)
104{
105 return coresight_read_claim_tags(csdev) == CORESIGHT_CLAIM_SELF_HOSTED;
106}
107
108static inline bool coresight_is_claimed_any(struct coresight_device *csdev)
109{
110 return coresight_read_claim_tags(csdev) != 0;
111}
112
113static inline void coresight_set_claim_tags(struct coresight_device *csdev)
114{
115 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
116 CORESIGHT_CLAIMSET);
117 isb();
118}
119
120static inline void coresight_clear_claim_tags(struct coresight_device *csdev)
121{
122 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
123 CORESIGHT_CLAIMCLR);
124 isb();
125}
126
127/*
128 * coresight_claim_device_unlocked : Claim the device for self-hosted usage
129 * to prevent an external tool from touching this device. As per PSCI
130 * standards, section "Preserving the execution context" => "Debug and Trace
131 * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and
132 * DBGCLAIM[0] is reserved for external tools.
133 *
134 * Called with CS_UNLOCKed for the component.
135 * Returns : 0 on success
136 */
137int coresight_claim_device_unlocked(struct coresight_device *csdev)
138{
139 if (WARN_ON(!csdev))
140 return -EINVAL;
141
142 if (coresight_is_claimed_any(csdev))
143 return -EBUSY;
144
145 coresight_set_claim_tags(csdev);
146 if (coresight_is_claimed_self_hosted(csdev))
147 return 0;
148 /* There was a race setting the tags, clean up and fail */
149 coresight_clear_claim_tags(csdev);
150 return -EBUSY;
151}
152EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);
153
154int coresight_claim_device(struct coresight_device *csdev)
155{
156 int rc;
157
158 if (WARN_ON(!csdev))
159 return -EINVAL;
160
161 CS_UNLOCK(csdev->access.base);
162 rc = coresight_claim_device_unlocked(csdev);
163 CS_LOCK(csdev->access.base);
164
165 return rc;
166}
167EXPORT_SYMBOL_GPL(coresight_claim_device);
168
169/*
170 * coresight_disclaim_device_unlocked : Clear the claim tags for the device.
171 * Called with CS_UNLOCKed for the component.
172 */
173void coresight_disclaim_device_unlocked(struct coresight_device *csdev)
174{
175
176 if (WARN_ON(!csdev))
177 return;
178
179 if (coresight_is_claimed_self_hosted(csdev))
180 coresight_clear_claim_tags(csdev);
181 else
182 /*
183 * The external agent may have not honoured our claim
184 * and has manipulated it. Or something else has seriously
185 * gone wrong in our driver.
186 */
187 WARN_ON_ONCE(1);
188}
189EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
190
191void coresight_disclaim_device(struct coresight_device *csdev)
192{
193 if (WARN_ON(!csdev))
194 return;
195
196 CS_UNLOCK(csdev->access.base);
197 coresight_disclaim_device_unlocked(csdev);
198 CS_LOCK(csdev->access.base);
199}
200EXPORT_SYMBOL_GPL(coresight_disclaim_device);
201
202/*
203 * Add a helper as an output device. This function takes the @coresight_mutex
204 * because it's assumed that it's called from the helper device, outside of the
205 * core code where the mutex would already be held. Don't add new calls to this
206 * from inside the core code, instead try to add the new helper to the DT and
207 * ACPI where it will be picked up and linked automatically.
208 */
209void coresight_add_helper(struct coresight_device *csdev,
210 struct coresight_device *helper)
211{
212 int i;
213 struct coresight_connection conn = {};
214 struct coresight_connection *new_conn;
215
216 mutex_lock(&coresight_mutex);
217 conn.dest_fwnode = fwnode_handle_get(dev_fwnode(&helper->dev));
218 conn.dest_dev = helper;
219 conn.dest_port = conn.src_port = -1;
220 conn.src_dev = csdev;
221
222 /*
223 * Check for duplicates because this is called every time a helper
224 * device is re-loaded. Existing connections will get re-linked
225 * automatically.
226 */
227 for (i = 0; i < csdev->pdata->nr_outconns; ++i)
228 if (csdev->pdata->out_conns[i]->dest_fwnode == conn.dest_fwnode)
229 goto unlock;
230
231 new_conn = coresight_add_out_conn(csdev->dev.parent, csdev->pdata,
232 &conn);
233 if (!IS_ERR(new_conn))
234 coresight_add_in_conn(new_conn);
235
236unlock:
237 mutex_unlock(&coresight_mutex);
238}
239EXPORT_SYMBOL_GPL(coresight_add_helper);
240
241static int coresight_enable_sink(struct coresight_device *csdev,
242 enum cs_mode mode, void *data)
243{
244 return sink_ops(csdev)->enable(csdev, mode, data);
245}
246
247static void coresight_disable_sink(struct coresight_device *csdev)
248{
249 sink_ops(csdev)->disable(csdev);
250}
251
252static int coresight_enable_link(struct coresight_device *csdev,
253 struct coresight_device *parent,
254 struct coresight_device *child)
255{
256 int link_subtype;
257 struct coresight_connection *inconn, *outconn;
258
259 if (!parent || !child)
260 return -EINVAL;
261
262 inconn = coresight_find_out_connection(parent, csdev);
263 outconn = coresight_find_out_connection(csdev, child);
264 link_subtype = csdev->subtype.link_subtype;
265
266 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && IS_ERR(inconn))
267 return PTR_ERR(inconn);
268 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && IS_ERR(outconn))
269 return PTR_ERR(outconn);
270
271 return link_ops(csdev)->enable(csdev, inconn, outconn);
272}
273
274static void coresight_disable_link(struct coresight_device *csdev,
275 struct coresight_device *parent,
276 struct coresight_device *child)
277{
278 struct coresight_connection *inconn, *outconn;
279
280 if (!parent || !child)
281 return;
282
283 inconn = coresight_find_out_connection(parent, csdev);
284 outconn = coresight_find_out_connection(csdev, child);
285
286 link_ops(csdev)->disable(csdev, inconn, outconn);
287}
288
289static bool coresight_is_helper(struct coresight_device *csdev)
290{
291 return csdev->type == CORESIGHT_DEV_TYPE_HELPER;
292}
293
294static int coresight_enable_helper(struct coresight_device *csdev,
295 enum cs_mode mode, void *data)
296{
297 return helper_ops(csdev)->enable(csdev, mode, data);
298}
299
300static void coresight_disable_helper(struct coresight_device *csdev)
301{
302 helper_ops(csdev)->disable(csdev, NULL);
303}
304
305static void coresight_disable_helpers(struct coresight_device *csdev)
306{
307 int i;
308 struct coresight_device *helper;
309
310 for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
311 helper = csdev->pdata->out_conns[i]->dest_dev;
312 if (helper && coresight_is_helper(helper))
313 coresight_disable_helper(helper);
314 }
315}
316
317/*
318 * Helper function to call source_ops(csdev)->disable and also disable the
319 * helpers.
320 *
321 * There is an imbalance between coresight_enable_path() and
322 * coresight_disable_path(). Enabling also enables the source's helpers as part
323 * of the path, but disabling always skips the first item in the path (which is
324 * the source), so sources and their helpers don't get disabled as part of that
325 * function and we need the extra step here.
326 */
327void coresight_disable_source(struct coresight_device *csdev, void *data)
328{
329 source_ops(csdev)->disable(csdev, data);
330 coresight_disable_helpers(csdev);
331}
332EXPORT_SYMBOL_GPL(coresight_disable_source);
333
334/*
335 * coresight_disable_path_from : Disable components in the given path beyond
336 * @nd in the list. If @nd is NULL, all the components, except the SOURCE are
337 * disabled.
338 */
339static void coresight_disable_path_from(struct list_head *path,
340 struct coresight_node *nd)
341{
342 u32 type;
343 struct coresight_device *csdev, *parent, *child;
344
345 if (!nd)
346 nd = list_first_entry(path, struct coresight_node, link);
347
348 list_for_each_entry_continue(nd, path, link) {
349 csdev = nd->csdev;
350 type = csdev->type;
351
352 /*
353 * ETF devices are tricky... They can be a link or a sink,
354 * depending on how they are configured. If an ETF has been
355 * selected as a sink it will be configured as a sink, otherwise
356 * go ahead with the link configuration.
357 */
358 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
359 type = (csdev == coresight_get_sink(path)) ?
360 CORESIGHT_DEV_TYPE_SINK :
361 CORESIGHT_DEV_TYPE_LINK;
362
363 switch (type) {
364 case CORESIGHT_DEV_TYPE_SINK:
365 coresight_disable_sink(csdev);
366 break;
367 case CORESIGHT_DEV_TYPE_SOURCE:
368 /*
369 * We skip the first node in the path assuming that it
370 * is the source. So we don't expect a source device in
371 * the middle of a path.
372 */
373 WARN_ON(1);
374 break;
375 case CORESIGHT_DEV_TYPE_LINK:
376 parent = list_prev_entry(nd, link)->csdev;
377 child = list_next_entry(nd, link)->csdev;
378 coresight_disable_link(csdev, parent, child);
379 break;
380 default:
381 break;
382 }
383
384 /* Disable all helpers adjacent along the path last */
385 coresight_disable_helpers(csdev);
386 }
387}
388
389void coresight_disable_path(struct list_head *path)
390{
391 coresight_disable_path_from(path, NULL);
392}
393EXPORT_SYMBOL_GPL(coresight_disable_path);
394
395static int coresight_enable_helpers(struct coresight_device *csdev,
396 enum cs_mode mode, void *data)
397{
398 int i, ret = 0;
399 struct coresight_device *helper;
400
401 for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
402 helper = csdev->pdata->out_conns[i]->dest_dev;
403 if (!helper || !coresight_is_helper(helper))
404 continue;
405
406 ret = coresight_enable_helper(helper, mode, data);
407 if (ret)
408 return ret;
409 }
410
411 return 0;
412}
413
414int coresight_enable_path(struct list_head *path, enum cs_mode mode,
415 void *sink_data)
416{
417 int ret = 0;
418 u32 type;
419 struct coresight_node *nd;
420 struct coresight_device *csdev, *parent, *child;
421
422 list_for_each_entry_reverse(nd, path, link) {
423 csdev = nd->csdev;
424 type = csdev->type;
425
426 /* Enable all helpers adjacent to the path first */
427 ret = coresight_enable_helpers(csdev, mode, sink_data);
428 if (ret)
429 goto err;
430 /*
431 * ETF devices are tricky... They can be a link or a sink,
432 * depending on how they are configured. If an ETF has been
433 * selected as a sink it will be configured as a sink, otherwise
434 * go ahead with the link configuration.
435 */
436 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
437 type = (csdev == coresight_get_sink(path)) ?
438 CORESIGHT_DEV_TYPE_SINK :
439 CORESIGHT_DEV_TYPE_LINK;
440
441 switch (type) {
442 case CORESIGHT_DEV_TYPE_SINK:
443 ret = coresight_enable_sink(csdev, mode, sink_data);
444 /*
445 * Sink is the first component turned on. If we
446 * failed to enable the sink, there are no components
447 * that need disabling. Disabling the path here
448 * would mean we could disrupt an existing session.
449 */
450 if (ret)
451 goto out;
452 break;
453 case CORESIGHT_DEV_TYPE_SOURCE:
454 /* sources are enabled from either sysFS or Perf */
455 break;
456 case CORESIGHT_DEV_TYPE_LINK:
457 parent = list_prev_entry(nd, link)->csdev;
458 child = list_next_entry(nd, link)->csdev;
459 ret = coresight_enable_link(csdev, parent, child);
460 if (ret)
461 goto err;
462 break;
463 default:
464 goto err;
465 }
466 }
467
468out:
469 return ret;
470err:
471 coresight_disable_path_from(path, nd);
472 goto out;
473}
474
475struct coresight_device *coresight_get_sink(struct list_head *path)
476{
477 struct coresight_device *csdev;
478
479 if (!path)
480 return NULL;
481
482 csdev = list_last_entry(path, struct coresight_node, link)->csdev;
483 if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
484 csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
485 return NULL;
486
487 return csdev;
488}
489
490static int coresight_sink_by_id(struct device *dev, const void *data)
491{
492 struct coresight_device *csdev = to_coresight_device(dev);
493 unsigned long hash;
494
495 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
496 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
497
498 if (!csdev->ea)
499 return 0;
500 /*
501 * See function etm_perf_add_symlink_sink() to know where
502 * this comes from.
503 */
504 hash = (unsigned long)csdev->ea->var;
505
506 if ((u32)hash == *(u32 *)data)
507 return 1;
508 }
509
510 return 0;
511}
512
513/**
514 * coresight_get_sink_by_id - returns the sink that matches the id
515 * @id: Id of the sink to match
516 *
517 * The name of a sink is unique, whether it is found on the AMBA bus or
518 * otherwise. As such the hash of that name can easily be used to identify
519 * a sink.
520 */
521struct coresight_device *coresight_get_sink_by_id(u32 id)
522{
523 struct device *dev = NULL;
524
525 dev = bus_find_device(&coresight_bustype, NULL, &id,
526 coresight_sink_by_id);
527
528 return dev ? to_coresight_device(dev) : NULL;
529}
530
531/**
532 * coresight_get_ref- Helper function to increase reference count to module
533 * and device.
534 *
535 * @csdev: The coresight device to get a reference on.
536 *
537 * Return true in successful case and power up the device.
538 * Return false when failed to get reference of module.
539 */
540static inline bool coresight_get_ref(struct coresight_device *csdev)
541{
542 struct device *dev = csdev->dev.parent;
543
544 /* Make sure the driver can't be removed */
545 if (!try_module_get(dev->driver->owner))
546 return false;
547 /* Make sure the device can't go away */
548 get_device(dev);
549 pm_runtime_get_sync(dev);
550 return true;
551}
552
553/**
554 * coresight_put_ref- Helper function to decrease reference count to module
555 * and device. Power off the device.
556 *
557 * @csdev: The coresight device to decrement a reference from.
558 */
559static inline void coresight_put_ref(struct coresight_device *csdev)
560{
561 struct device *dev = csdev->dev.parent;
562
563 pm_runtime_put(dev);
564 put_device(dev);
565 module_put(dev->driver->owner);
566}
567
568/*
569 * coresight_grab_device - Power up this device and any of the helper
570 * devices connected to it for trace operation. Since the helper devices
571 * don't appear on the trace path, they should be handled along with the
572 * master device.
573 */
574static int coresight_grab_device(struct coresight_device *csdev)
575{
576 int i;
577
578 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
579 struct coresight_device *child;
580
581 child = csdev->pdata->out_conns[i]->dest_dev;
582 if (child && coresight_is_helper(child))
583 if (!coresight_get_ref(child))
584 goto err;
585 }
586 if (coresight_get_ref(csdev))
587 return 0;
588err:
589 for (i--; i >= 0; i--) {
590 struct coresight_device *child;
591
592 child = csdev->pdata->out_conns[i]->dest_dev;
593 if (child && coresight_is_helper(child))
594 coresight_put_ref(child);
595 }
596 return -ENODEV;
597}
598
599/*
600 * coresight_drop_device - Release this device and any of the helper
601 * devices connected to it.
602 */
603static void coresight_drop_device(struct coresight_device *csdev)
604{
605 int i;
606
607 coresight_put_ref(csdev);
608 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
609 struct coresight_device *child;
610
611 child = csdev->pdata->out_conns[i]->dest_dev;
612 if (child && coresight_is_helper(child))
613 coresight_put_ref(child);
614 }
615}
616
617/**
618 * _coresight_build_path - recursively build a path from a @csdev to a sink.
619 * @csdev: The device to start from.
620 * @sink: The final sink we want in this path.
621 * @path: The list to add devices to.
622 *
623 * The tree of Coresight device is traversed until @sink is found.
624 * From there the sink is added to the list along with all the devices that led
625 * to that point - the end result is a list from source to sink. In that list
626 * the source is the first device and the sink the last one.
627 */
628static int _coresight_build_path(struct coresight_device *csdev,
629 struct coresight_device *sink,
630 struct list_head *path)
631{
632 int i, ret;
633 bool found = false;
634 struct coresight_node *node;
635
636 /* The sink has been found. Enqueue the element */
637 if (csdev == sink)
638 goto out;
639
640 if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) &&
641 sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) {
642 if (_coresight_build_path(sink, sink, path) == 0) {
643 found = true;
644 goto out;
645 }
646 }
647
648 /* Not a sink - recursively explore each port found on this element */
649 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
650 struct coresight_device *child_dev;
651
652 child_dev = csdev->pdata->out_conns[i]->dest_dev;
653 if (child_dev &&
654 _coresight_build_path(child_dev, sink, path) == 0) {
655 found = true;
656 break;
657 }
658 }
659
660 if (!found)
661 return -ENODEV;
662
663out:
664 /*
665 * A path from this element to a sink has been found. The elements
666 * leading to the sink are already enqueued, all that is left to do
667 * is tell the PM runtime core we need this element and add a node
668 * for it.
669 */
670 ret = coresight_grab_device(csdev);
671 if (ret)
672 return ret;
673
674 node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
675 if (!node)
676 return -ENOMEM;
677
678 node->csdev = csdev;
679 list_add(&node->link, path);
680
681 return 0;
682}
683
684struct list_head *coresight_build_path(struct coresight_device *source,
685 struct coresight_device *sink)
686{
687 struct list_head *path;
688 int rc;
689
690 if (!sink)
691 return ERR_PTR(-EINVAL);
692
693 path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
694 if (!path)
695 return ERR_PTR(-ENOMEM);
696
697 INIT_LIST_HEAD(path);
698
699 rc = _coresight_build_path(source, sink, path);
700 if (rc) {
701 kfree(path);
702 return ERR_PTR(rc);
703 }
704
705 return path;
706}
707
708/**
709 * coresight_release_path - release a previously built path.
710 * @path: the path to release.
711 *
712 * Go through all the elements of a path and 1) removed it from the list and
713 * 2) free the memory allocated for each node.
714 */
715void coresight_release_path(struct list_head *path)
716{
717 struct coresight_device *csdev;
718 struct coresight_node *nd, *next;
719
720 list_for_each_entry_safe(nd, next, path, link) {
721 csdev = nd->csdev;
722
723 coresight_drop_device(csdev);
724 list_del(&nd->link);
725 kfree(nd);
726 }
727
728 kfree(path);
729}
730
731/* return true if the device is a suitable type for a default sink */
732static inline bool coresight_is_def_sink_type(struct coresight_device *csdev)
733{
734 /* sink & correct subtype */
735 if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
736 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) &&
737 (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER))
738 return true;
739 return false;
740}
741
742/**
743 * coresight_select_best_sink - return the best sink for use as default from
744 * the two provided.
745 *
746 * @sink: current best sink.
747 * @depth: search depth where current sink was found.
748 * @new_sink: new sink for comparison with current sink.
749 * @new_depth: search depth where new sink was found.
750 *
751 * Sinks prioritised according to coresight_dev_subtype_sink, with only
752 * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used.
753 *
754 * Where two sinks of equal priority are found, the sink closest to the
755 * source is used (smallest search depth).
756 *
757 * return @new_sink & update @depth if better than @sink, else return @sink.
758 */
759static struct coresight_device *
760coresight_select_best_sink(struct coresight_device *sink, int *depth,
761 struct coresight_device *new_sink, int new_depth)
762{
763 bool update = false;
764
765 if (!sink) {
766 /* first found at this level */
767 update = true;
768 } else if (new_sink->subtype.sink_subtype >
769 sink->subtype.sink_subtype) {
770 /* found better sink */
771 update = true;
772 } else if ((new_sink->subtype.sink_subtype ==
773 sink->subtype.sink_subtype) &&
774 (*depth > new_depth)) {
775 /* found same but closer sink */
776 update = true;
777 }
778
779 if (update)
780 *depth = new_depth;
781 return update ? new_sink : sink;
782}
783
784/**
785 * coresight_find_sink - recursive function to walk trace connections from
786 * source to find a suitable default sink.
787 *
788 * @csdev: source / current device to check.
789 * @depth: [in] search depth of calling dev, [out] depth of found sink.
790 *
791 * This will walk the connection path from a source (ETM) till a suitable
792 * sink is encountered and return that sink to the original caller.
793 *
794 * If current device is a plain sink return that & depth, otherwise recursively
795 * call child connections looking for a sink. Select best possible using
796 * coresight_select_best_sink.
797 *
798 * return best sink found, or NULL if not found at this node or child nodes.
799 */
800static struct coresight_device *
801coresight_find_sink(struct coresight_device *csdev, int *depth)
802{
803 int i, curr_depth = *depth + 1, found_depth = 0;
804 struct coresight_device *found_sink = NULL;
805
806 if (coresight_is_def_sink_type(csdev)) {
807 found_depth = curr_depth;
808 found_sink = csdev;
809 if (csdev->type == CORESIGHT_DEV_TYPE_SINK)
810 goto return_def_sink;
811 /* look past LINKSINK for something better */
812 }
813
814 /*
815 * Not a sink we want - or possible child sink may be better.
816 * recursively explore each port found on this element.
817 */
818 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
819 struct coresight_device *child_dev, *sink = NULL;
820 int child_depth = curr_depth;
821
822 child_dev = csdev->pdata->out_conns[i]->dest_dev;
823 if (child_dev)
824 sink = coresight_find_sink(child_dev, &child_depth);
825
826 if (sink)
827 found_sink = coresight_select_best_sink(found_sink,
828 &found_depth,
829 sink,
830 child_depth);
831 }
832
833return_def_sink:
834 /* return found sink and depth */
835 if (found_sink)
836 *depth = found_depth;
837 return found_sink;
838}
839
840/**
841 * coresight_find_default_sink: Find a sink suitable for use as a
842 * default sink.
843 *
844 * @csdev: starting source to find a connected sink.
845 *
846 * Walks connections graph looking for a suitable sink to enable for the
847 * supplied source. Uses CoreSight device subtypes and distance from source
848 * to select the best sink.
849 *
850 * If a sink is found, then the default sink for this device is set and
851 * will be automatically used in future.
852 *
853 * Used in cases where the CoreSight user (perf / sysfs) has not selected a
854 * sink.
855 */
856struct coresight_device *
857coresight_find_default_sink(struct coresight_device *csdev)
858{
859 int depth = 0;
860
861 /* look for a default sink if we have not found for this device */
862 if (!csdev->def_sink) {
863 if (coresight_is_percpu_source(csdev))
864 csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev));
865 if (!csdev->def_sink)
866 csdev->def_sink = coresight_find_sink(csdev, &depth);
867 }
868 return csdev->def_sink;
869}
870
871static int coresight_remove_sink_ref(struct device *dev, void *data)
872{
873 struct coresight_device *sink = data;
874 struct coresight_device *source = to_coresight_device(dev);
875
876 if (source->def_sink == sink)
877 source->def_sink = NULL;
878 return 0;
879}
880
881/**
882 * coresight_clear_default_sink: Remove all default sink references to the
883 * supplied sink.
884 *
885 * If supplied device is a sink, then check all the bus devices and clear
886 * out all the references to this sink from the coresight_device def_sink
887 * parameter.
888 *
889 * @csdev: coresight sink - remove references to this from all sources.
890 */
891static void coresight_clear_default_sink(struct coresight_device *csdev)
892{
893 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
894 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) {
895 bus_for_each_dev(&coresight_bustype, NULL, csdev,
896 coresight_remove_sink_ref);
897 }
898}
899
900static void coresight_device_release(struct device *dev)
901{
902 struct coresight_device *csdev = to_coresight_device(dev);
903
904 fwnode_handle_put(csdev->dev.fwnode);
905 kfree(csdev);
906}
907
908static int coresight_orphan_match(struct device *dev, void *data)
909{
910 int i, ret = 0;
911 bool still_orphan = false;
912 struct coresight_device *dst_csdev = data;
913 struct coresight_device *src_csdev = to_coresight_device(dev);
914 struct coresight_connection *conn;
915 bool fixup_self = (src_csdev == dst_csdev);
916
917 /* Move on to another component if no connection is orphan */
918 if (!src_csdev->orphan)
919 return 0;
920 /*
921 * Circle through all the connections of that component. If we find
922 * an orphan connection whose name matches @dst_csdev, link it.
923 */
924 for (i = 0; i < src_csdev->pdata->nr_outconns; i++) {
925 conn = src_csdev->pdata->out_conns[i];
926
927 /* Skip the port if it's already connected. */
928 if (conn->dest_dev)
929 continue;
930
931 /*
932 * If we are at the "new" device, which triggered this search,
933 * we must find the remote device from the fwnode in the
934 * connection.
935 */
936 if (fixup_self)
937 dst_csdev = coresight_find_csdev_by_fwnode(
938 conn->dest_fwnode);
939
940 /* Does it match this newly added device? */
941 if (dst_csdev && conn->dest_fwnode == dst_csdev->dev.fwnode) {
942 ret = coresight_make_links(src_csdev, conn, dst_csdev);
943 if (ret)
944 return ret;
945
946 /*
947 * Install the device connection. This also indicates that
948 * the links are operational on both ends.
949 */
950 conn->dest_dev = dst_csdev;
951 conn->src_dev = src_csdev;
952
953 ret = coresight_add_in_conn(conn);
954 if (ret)
955 return ret;
956 } else {
957 /* This component still has an orphan */
958 still_orphan = true;
959 }
960 }
961
962 src_csdev->orphan = still_orphan;
963
964 /*
965 * Returning '0' in case we didn't encounter any error,
966 * ensures that all known component on the bus will be checked.
967 */
968 return 0;
969}
970
971static int coresight_fixup_orphan_conns(struct coresight_device *csdev)
972{
973 return bus_for_each_dev(&coresight_bustype, NULL,
974 csdev, coresight_orphan_match);
975}
976
977/* coresight_remove_conns - Remove other device's references to this device */
978static void coresight_remove_conns(struct coresight_device *csdev)
979{
980 int i, j;
981 struct coresight_connection *conn;
982
983 /*
984 * Remove the input connection references from the destination device
985 * for each output connection.
986 */
987 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
988 conn = csdev->pdata->out_conns[i];
989 if (!conn->dest_dev)
990 continue;
991
992 for (j = 0; j < conn->dest_dev->pdata->nr_inconns; ++j)
993 if (conn->dest_dev->pdata->in_conns[j] == conn) {
994 conn->dest_dev->pdata->in_conns[j] = NULL;
995 break;
996 }
997 }
998
999 /*
1000 * For all input connections, remove references to this device.
1001 * Connection objects are shared so modifying this device's input
1002 * connections affects the other device's output connection.
1003 */
1004 for (i = 0; i < csdev->pdata->nr_inconns; ++i) {
1005 conn = csdev->pdata->in_conns[i];
1006 /* Input conns array is sparse */
1007 if (!conn)
1008 continue;
1009
1010 conn->src_dev->orphan = true;
1011 coresight_remove_links(conn->src_dev, conn);
1012 conn->dest_dev = NULL;
1013 }
1014}
1015
1016/**
1017 * coresight_timeout - loop until a bit has changed to a specific register
1018 * state.
1019 * @csa: coresight device access for the device
1020 * @offset: Offset of the register from the base of the device.
1021 * @position: the position of the bit of interest.
1022 * @value: the value the bit should have.
1023 *
1024 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
1025 * TIMEOUT_US has elapsed, which ever happens first.
1026 */
1027int coresight_timeout(struct csdev_access *csa, u32 offset,
1028 int position, int value)
1029{
1030 int i;
1031 u32 val;
1032
1033 for (i = TIMEOUT_US; i > 0; i--) {
1034 val = csdev_access_read32(csa, offset);
1035 /* waiting on the bit to go from 0 to 1 */
1036 if (value) {
1037 if (val & BIT(position))
1038 return 0;
1039 /* waiting on the bit to go from 1 to 0 */
1040 } else {
1041 if (!(val & BIT(position)))
1042 return 0;
1043 }
1044
1045 /*
1046 * Delay is arbitrary - the specification doesn't say how long
1047 * we are expected to wait. Extra check required to make sure
1048 * we don't wait needlessly on the last iteration.
1049 */
1050 if (i - 1)
1051 udelay(1);
1052 }
1053
1054 return -EAGAIN;
1055}
1056EXPORT_SYMBOL_GPL(coresight_timeout);
1057
1058u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)
1059{
1060 return csdev_access_relaxed_read32(&csdev->access, offset);
1061}
1062
1063u32 coresight_read32(struct coresight_device *csdev, u32 offset)
1064{
1065 return csdev_access_read32(&csdev->access, offset);
1066}
1067
1068void coresight_relaxed_write32(struct coresight_device *csdev,
1069 u32 val, u32 offset)
1070{
1071 csdev_access_relaxed_write32(&csdev->access, val, offset);
1072}
1073
1074void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)
1075{
1076 csdev_access_write32(&csdev->access, val, offset);
1077}
1078
1079u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset)
1080{
1081 return csdev_access_relaxed_read64(&csdev->access, offset);
1082}
1083
1084u64 coresight_read64(struct coresight_device *csdev, u32 offset)
1085{
1086 return csdev_access_read64(&csdev->access, offset);
1087}
1088
1089void coresight_relaxed_write64(struct coresight_device *csdev,
1090 u64 val, u32 offset)
1091{
1092 csdev_access_relaxed_write64(&csdev->access, val, offset);
1093}
1094
1095void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
1096{
1097 csdev_access_write64(&csdev->access, val, offset);
1098}
1099
1100/*
1101 * coresight_release_platform_data: Release references to the devices connected
1102 * to the output port of this device.
1103 */
1104void coresight_release_platform_data(struct coresight_device *csdev,
1105 struct device *dev,
1106 struct coresight_platform_data *pdata)
1107{
1108 int i;
1109 struct coresight_connection **conns = pdata->out_conns;
1110
1111 for (i = 0; i < pdata->nr_outconns; i++) {
1112 /* If we have made the links, remove them now */
1113 if (csdev && conns[i]->dest_dev)
1114 coresight_remove_links(csdev, conns[i]);
1115 /*
1116 * Drop the refcount and clear the handle as this device
1117 * is going away
1118 */
1119 fwnode_handle_put(conns[i]->dest_fwnode);
1120 conns[i]->dest_fwnode = NULL;
1121 devm_kfree(dev, conns[i]);
1122 }
1123 devm_kfree(dev, pdata->out_conns);
1124 devm_kfree(dev, pdata->in_conns);
1125 devm_kfree(dev, pdata);
1126 if (csdev)
1127 coresight_remove_conns_sysfs_group(csdev);
1128}
1129
1130struct coresight_device *coresight_register(struct coresight_desc *desc)
1131{
1132 int ret;
1133 struct coresight_device *csdev;
1134 bool registered = false;
1135
1136 csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
1137 if (!csdev) {
1138 ret = -ENOMEM;
1139 goto err_out;
1140 }
1141
1142 csdev->pdata = desc->pdata;
1143
1144 csdev->type = desc->type;
1145 csdev->subtype = desc->subtype;
1146 csdev->ops = desc->ops;
1147 csdev->access = desc->access;
1148 csdev->orphan = true;
1149
1150 csdev->dev.type = &coresight_dev_type[desc->type];
1151 csdev->dev.groups = desc->groups;
1152 csdev->dev.parent = desc->dev;
1153 csdev->dev.release = coresight_device_release;
1154 csdev->dev.bus = &coresight_bustype;
1155 /*
1156 * Hold the reference to our parent device. This will be
1157 * dropped only in coresight_device_release().
1158 */
1159 csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
1160 dev_set_name(&csdev->dev, "%s", desc->name);
1161
1162 /*
1163 * Make sure the device registration and the connection fixup
1164 * are synchronised, so that we don't see uninitialised devices
1165 * on the coresight bus while trying to resolve the connections.
1166 */
1167 mutex_lock(&coresight_mutex);
1168
1169 ret = device_register(&csdev->dev);
1170 if (ret) {
1171 put_device(&csdev->dev);
1172 /*
1173 * All resources are free'd explicitly via
1174 * coresight_device_release(), triggered from put_device().
1175 */
1176 goto out_unlock;
1177 }
1178
1179 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
1180 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
1181 ret = etm_perf_add_symlink_sink(csdev);
1182
1183 if (ret) {
1184 device_unregister(&csdev->dev);
1185 /*
1186 * As with the above, all resources are free'd
1187 * explicitly via coresight_device_release() triggered
1188 * from put_device(), which is in turn called from
1189 * function device_unregister().
1190 */
1191 goto out_unlock;
1192 }
1193 }
1194 /* Device is now registered */
1195 registered = true;
1196
1197 ret = coresight_create_conns_sysfs_group(csdev);
1198 if (!ret)
1199 ret = coresight_fixup_orphan_conns(csdev);
1200
1201out_unlock:
1202 mutex_unlock(&coresight_mutex);
1203 /* Success */
1204 if (!ret) {
1205 if (cti_assoc_ops && cti_assoc_ops->add)
1206 cti_assoc_ops->add(csdev);
1207 return csdev;
1208 }
1209
1210 /* Unregister the device if needed */
1211 if (registered) {
1212 coresight_unregister(csdev);
1213 return ERR_PTR(ret);
1214 }
1215
1216err_out:
1217 /* Cleanup the connection information */
1218 coresight_release_platform_data(NULL, desc->dev, desc->pdata);
1219 return ERR_PTR(ret);
1220}
1221EXPORT_SYMBOL_GPL(coresight_register);
1222
1223void coresight_unregister(struct coresight_device *csdev)
1224{
1225 etm_perf_del_symlink_sink(csdev);
1226 /* Remove references of that device in the topology */
1227 if (cti_assoc_ops && cti_assoc_ops->remove)
1228 cti_assoc_ops->remove(csdev);
1229 coresight_remove_conns(csdev);
1230 coresight_clear_default_sink(csdev);
1231 coresight_release_platform_data(csdev, csdev->dev.parent, csdev->pdata);
1232 device_unregister(&csdev->dev);
1233}
1234EXPORT_SYMBOL_GPL(coresight_unregister);
1235
1236
1237/*
1238 * coresight_search_device_idx - Search the fwnode handle of a device
1239 * in the given dev_idx list. Must be called with the coresight_mutex held.
1240 *
1241 * Returns the index of the entry, when found. Otherwise, -ENOENT.
1242 */
1243static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
1244 struct fwnode_handle *fwnode)
1245{
1246 int i;
1247
1248 for (i = 0; i < dict->nr_idx; i++)
1249 if (dict->fwnode_list[i] == fwnode)
1250 return i;
1251 return -ENOENT;
1252}
1253
1254static bool coresight_compare_type(enum coresight_dev_type type_a,
1255 union coresight_dev_subtype subtype_a,
1256 enum coresight_dev_type type_b,
1257 union coresight_dev_subtype subtype_b)
1258{
1259 if (type_a != type_b)
1260 return false;
1261
1262 switch (type_a) {
1263 case CORESIGHT_DEV_TYPE_SINK:
1264 return subtype_a.sink_subtype == subtype_b.sink_subtype;
1265 case CORESIGHT_DEV_TYPE_LINK:
1266 return subtype_a.link_subtype == subtype_b.link_subtype;
1267 case CORESIGHT_DEV_TYPE_LINKSINK:
1268 return subtype_a.link_subtype == subtype_b.link_subtype &&
1269 subtype_a.sink_subtype == subtype_b.sink_subtype;
1270 case CORESIGHT_DEV_TYPE_SOURCE:
1271 return subtype_a.source_subtype == subtype_b.source_subtype;
1272 case CORESIGHT_DEV_TYPE_HELPER:
1273 return subtype_a.helper_subtype == subtype_b.helper_subtype;
1274 default:
1275 return false;
1276 }
1277}
1278
1279struct coresight_device *
1280coresight_find_input_type(struct coresight_platform_data *pdata,
1281 enum coresight_dev_type type,
1282 union coresight_dev_subtype subtype)
1283{
1284 int i;
1285 struct coresight_connection *conn;
1286
1287 for (i = 0; i < pdata->nr_inconns; ++i) {
1288 conn = pdata->in_conns[i];
1289 if (conn &&
1290 coresight_compare_type(type, subtype, conn->src_dev->type,
1291 conn->src_dev->subtype))
1292 return conn->src_dev;
1293 }
1294 return NULL;
1295}
1296EXPORT_SYMBOL_GPL(coresight_find_input_type);
1297
1298struct coresight_device *
1299coresight_find_output_type(struct coresight_platform_data *pdata,
1300 enum coresight_dev_type type,
1301 union coresight_dev_subtype subtype)
1302{
1303 int i;
1304 struct coresight_connection *conn;
1305
1306 for (i = 0; i < pdata->nr_outconns; ++i) {
1307 conn = pdata->out_conns[i];
1308 if (conn->dest_dev &&
1309 coresight_compare_type(type, subtype, conn->dest_dev->type,
1310 conn->dest_dev->subtype))
1311 return conn->dest_dev;
1312 }
1313 return NULL;
1314}
1315EXPORT_SYMBOL_GPL(coresight_find_output_type);
1316
1317bool coresight_loses_context_with_cpu(struct device *dev)
1318{
1319 return fwnode_property_present(dev_fwnode(dev),
1320 "arm,coresight-loses-context-with-cpu");
1321}
1322EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu);
1323
1324/*
1325 * coresight_alloc_device_name - Get an index for a given device in the
1326 * device index list specific to a driver. An index is allocated for a
1327 * device and is tracked with the fwnode_handle to prevent allocating
1328 * duplicate indices for the same device (e.g, if we defer probing of
1329 * a device due to dependencies), in case the index is requested again.
1330 */
1331char *coresight_alloc_device_name(struct coresight_dev_list *dict,
1332 struct device *dev)
1333{
1334 int idx;
1335 char *name = NULL;
1336 struct fwnode_handle **list;
1337
1338 mutex_lock(&coresight_mutex);
1339
1340 idx = coresight_search_device_idx(dict, dev_fwnode(dev));
1341 if (idx < 0) {
1342 /* Make space for the new entry */
1343 idx = dict->nr_idx;
1344 list = krealloc_array(dict->fwnode_list,
1345 idx + 1, sizeof(*dict->fwnode_list),
1346 GFP_KERNEL);
1347 if (ZERO_OR_NULL_PTR(list)) {
1348 idx = -ENOMEM;
1349 goto done;
1350 }
1351
1352 list[idx] = dev_fwnode(dev);
1353 dict->fwnode_list = list;
1354 dict->nr_idx = idx + 1;
1355 }
1356
1357 name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
1358done:
1359 mutex_unlock(&coresight_mutex);
1360 return name;
1361}
1362EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
1363
1364const struct bus_type coresight_bustype = {
1365 .name = "coresight",
1366};
1367
1368static int __init coresight_init(void)
1369{
1370 int ret;
1371
1372 ret = bus_register(&coresight_bustype);
1373 if (ret)
1374 return ret;
1375
1376 ret = etm_perf_init();
1377 if (ret)
1378 goto exit_bus_unregister;
1379
1380 /* initialise the coresight syscfg API */
1381 ret = cscfg_init();
1382 if (!ret)
1383 return 0;
1384
1385 etm_perf_exit();
1386exit_bus_unregister:
1387 bus_unregister(&coresight_bustype);
1388 return ret;
1389}
1390
1391static void __exit coresight_exit(void)
1392{
1393 cscfg_exit();
1394 etm_perf_exit();
1395 bus_unregister(&coresight_bustype);
1396}
1397
1398module_init(coresight_init);
1399module_exit(coresight_exit);
1400
1401MODULE_LICENSE("GPL v2");
1402MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1403MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
1404MODULE_DESCRIPTION("Arm CoreSight tracer driver");