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