1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
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>
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>
24 #include "coresight-etm-perf.h"
25 #include "coresight-priv.h"
26 #include "coresight-syscfg.h"
28 static DEFINE_MUTEX(coresight_mutex);
29 static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);
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.
36 static DEFINE_IDR(path_idr);
39 * struct coresight_node - elements of a path, from source to sink
40 * @csdev: Address of an element.
41 * @link: hook to the list.
43 struct coresight_node {
44 struct coresight_device *csdev;
45 struct list_head link;
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.
52 static DEFINE_PER_CPU(struct list_head *, tracer_path);
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.
59 const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
60 EXPORT_SYMBOL_GPL(coresight_barrier_pkt);
62 static const struct cti_assoc_op *cti_assoc_ops;
64 ssize_t coresight_simple_show_pair(struct device *_dev,
65 struct device_attribute *attr, char *buf)
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);
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);
76 EXPORT_SYMBOL_GPL(coresight_simple_show_pair);
78 ssize_t coresight_simple_show32(struct device *_dev,
79 struct device_attribute *attr, char *buf)
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);
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);
90 EXPORT_SYMBOL_GPL(coresight_simple_show32);
92 void coresight_set_cti_ops(const struct cti_assoc_op *cti_op)
94 cti_assoc_ops = cti_op;
96 EXPORT_SYMBOL_GPL(coresight_set_cti_ops);
98 void coresight_remove_cti_ops(void)
100 cti_assoc_ops = NULL;
102 EXPORT_SYMBOL_GPL(coresight_remove_cti_ops);
104 void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev)
106 per_cpu(csdev_sink, cpu) = csdev;
108 EXPORT_SYMBOL_GPL(coresight_set_percpu_sink);
110 struct coresight_device *coresight_get_percpu_sink(int cpu)
112 return per_cpu(csdev_sink, cpu);
114 EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);
116 static struct coresight_connection *
117 coresight_find_out_connection(struct coresight_device *src_dev,
118 struct coresight_device *dest_dev)
121 struct coresight_connection *conn;
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)
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));
133 return ERR_PTR(-ENODEV);
136 static inline u32 coresight_read_claim_tags(struct coresight_device *csdev)
138 return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR);
141 static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev)
143 return coresight_read_claim_tags(csdev) == CORESIGHT_CLAIM_SELF_HOSTED;
146 static inline bool coresight_is_claimed_any(struct coresight_device *csdev)
148 return coresight_read_claim_tags(csdev) != 0;
151 static inline void coresight_set_claim_tags(struct coresight_device *csdev)
153 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
158 static inline void coresight_clear_claim_tags(struct coresight_device *csdev)
160 csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,
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.
172 * Called with CS_UNLOCKed for the component.
173 * Returns : 0 on success
175 int coresight_claim_device_unlocked(struct coresight_device *csdev)
180 if (coresight_is_claimed_any(csdev))
183 coresight_set_claim_tags(csdev);
184 if (coresight_is_claimed_self_hosted(csdev))
186 /* There was a race setting the tags, clean up and fail */
187 coresight_clear_claim_tags(csdev);
190 EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);
192 int coresight_claim_device(struct coresight_device *csdev)
199 CS_UNLOCK(csdev->access.base);
200 rc = coresight_claim_device_unlocked(csdev);
201 CS_LOCK(csdev->access.base);
205 EXPORT_SYMBOL_GPL(coresight_claim_device);
208 * coresight_disclaim_device_unlocked : Clear the claim tags for the device.
209 * Called with CS_UNLOCKed for the component.
211 void coresight_disclaim_device_unlocked(struct coresight_device *csdev)
217 if (coresight_is_claimed_self_hosted(csdev))
218 coresight_clear_claim_tags(csdev);
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.
227 EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
229 void coresight_disclaim_device(struct coresight_device *csdev)
234 CS_UNLOCK(csdev->access.base);
235 coresight_disclaim_device_unlocked(csdev);
236 CS_LOCK(csdev->access.base);
238 EXPORT_SYMBOL_GPL(coresight_disclaim_device);
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.
247 void coresight_add_helper(struct coresight_device *csdev,
248 struct coresight_device *helper)
251 struct coresight_connection conn = {};
252 struct coresight_connection *new_conn;
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;
261 * Check for duplicates because this is called every time a helper
262 * device is re-loaded. Existing connections will get re-linked
265 for (i = 0; i < csdev->pdata->nr_outconns; ++i)
266 if (csdev->pdata->out_conns[i]->dest_fwnode == conn.dest_fwnode)
269 new_conn = coresight_add_out_conn(csdev->dev.parent, csdev->pdata,
271 if (!IS_ERR(new_conn))
272 coresight_add_in_conn(new_conn);
275 mutex_unlock(&coresight_mutex);
277 EXPORT_SYMBOL_GPL(coresight_add_helper);
279 static int coresight_enable_sink(struct coresight_device *csdev,
280 enum cs_mode mode, void *data)
285 * We need to make sure the "new" session is compatible with the
286 * existing "mode" of operation.
288 if (!sink_ops(csdev)->enable)
291 ret = sink_ops(csdev)->enable(csdev, mode, data);
295 csdev->enable = true;
300 static void coresight_disable_sink(struct coresight_device *csdev)
304 if (!sink_ops(csdev)->disable)
307 ret = sink_ops(csdev)->disable(csdev);
310 csdev->enable = false;
313 static int coresight_enable_link(struct coresight_device *csdev,
314 struct coresight_device *parent,
315 struct coresight_device *child)
319 struct coresight_connection *inconn, *outconn;
321 if (!parent || !child)
324 inconn = coresight_find_out_connection(parent, csdev);
325 outconn = coresight_find_out_connection(csdev, child);
326 link_subtype = csdev->subtype.link_subtype;
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);
333 if (link_ops(csdev)->enable) {
334 ret = link_ops(csdev)->enable(csdev, inconn, outconn);
336 csdev->enable = true;
342 static void coresight_disable_link(struct coresight_device *csdev,
343 struct coresight_device *parent,
344 struct coresight_device *child)
348 struct coresight_connection *inconn, *outconn;
350 if (!parent || !child)
353 inconn = coresight_find_out_connection(parent, csdev);
354 outconn = coresight_find_out_connection(csdev, child);
355 link_subtype = csdev->subtype.link_subtype;
357 if (link_ops(csdev)->disable) {
358 link_ops(csdev)->disable(csdev, inconn, outconn);
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) !=
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) !=
372 if (atomic_read(&csdev->refcnt) != 0)
376 csdev->enable = false;
379 int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,
384 if (!csdev->enable) {
385 if (source_ops(csdev)->enable) {
386 ret = source_ops(csdev)->enable(csdev, data, mode);
390 csdev->enable = true;
393 atomic_inc(&csdev->refcnt);
397 EXPORT_SYMBOL_GPL(coresight_enable_source);
399 static bool coresight_is_helper(struct coresight_device *csdev)
401 return csdev->type == CORESIGHT_DEV_TYPE_HELPER;
404 static int coresight_enable_helper(struct coresight_device *csdev,
405 enum cs_mode mode, void *data)
409 if (!helper_ops(csdev)->enable)
411 ret = helper_ops(csdev)->enable(csdev, mode, data);
415 csdev->enable = true;
419 static void coresight_disable_helper(struct coresight_device *csdev)
423 if (!helper_ops(csdev)->disable)
426 ret = helper_ops(csdev)->disable(csdev, NULL);
429 csdev->enable = false;
432 static void coresight_disable_helpers(struct coresight_device *csdev)
435 struct coresight_device *helper;
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);
445 * Helper function to call source_ops(csdev)->disable and also disable the
448 * There is an imbalance between coresight_enable_path() and
449 * coresight_disable_path(). Enabling also enables the source's helpers as part
450 * of the path, but disabling always skips the first item in the path (which is
451 * the source), so sources and their helpers don't get disabled as part of that
452 * function and we need the extra step here.
454 void coresight_disable_source(struct coresight_device *csdev, void *data)
456 if (source_ops(csdev)->disable)
457 source_ops(csdev)->disable(csdev, data);
458 coresight_disable_helpers(csdev);
460 EXPORT_SYMBOL_GPL(coresight_disable_source);
463 * coresight_disable_source_sysfs - Drop the reference count by 1 and disable
464 * the device if there are no users left.
466 * @csdev: The coresight device to disable
467 * @data: Opaque data to pass on to the disable function of the source device.
468 * For example in perf mode this is a pointer to the struct perf_event.
470 * Returns true if the device has been disabled.
472 static bool coresight_disable_source_sysfs(struct coresight_device *csdev,
475 if (atomic_dec_return(&csdev->refcnt) == 0) {
476 coresight_disable_source(csdev, data);
477 csdev->enable = false;
479 return !csdev->enable;
483 * coresight_disable_path_from : Disable components in the given path beyond
484 * @nd in the list. If @nd is NULL, all the components, except the SOURCE are
487 static void coresight_disable_path_from(struct list_head *path,
488 struct coresight_node *nd)
491 struct coresight_device *csdev, *parent, *child;
494 nd = list_first_entry(path, struct coresight_node, link);
496 list_for_each_entry_continue(nd, path, link) {
501 * ETF devices are tricky... They can be a link or a sink,
502 * depending on how they are configured. If an ETF has been
503 * "activated" it will be configured as a sink, otherwise
504 * go ahead with the link configuration.
506 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
507 type = (csdev == coresight_get_sink(path)) ?
508 CORESIGHT_DEV_TYPE_SINK :
509 CORESIGHT_DEV_TYPE_LINK;
512 case CORESIGHT_DEV_TYPE_SINK:
513 coresight_disable_sink(csdev);
515 case CORESIGHT_DEV_TYPE_SOURCE:
517 * We skip the first node in the path assuming that it
518 * is the source. So we don't expect a source device in
519 * the middle of a path.
523 case CORESIGHT_DEV_TYPE_LINK:
524 parent = list_prev_entry(nd, link)->csdev;
525 child = list_next_entry(nd, link)->csdev;
526 coresight_disable_link(csdev, parent, child);
532 /* Disable all helpers adjacent along the path last */
533 coresight_disable_helpers(csdev);
537 void coresight_disable_path(struct list_head *path)
539 coresight_disable_path_from(path, NULL);
541 EXPORT_SYMBOL_GPL(coresight_disable_path);
543 static int coresight_enable_helpers(struct coresight_device *csdev,
544 enum cs_mode mode, void *data)
547 struct coresight_device *helper;
549 for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
550 helper = csdev->pdata->out_conns[i]->dest_dev;
551 if (!helper || !coresight_is_helper(helper))
554 ret = coresight_enable_helper(helper, mode, data);
562 int coresight_enable_path(struct list_head *path, enum cs_mode mode,
567 struct coresight_node *nd;
568 struct coresight_device *csdev, *parent, *child;
570 list_for_each_entry_reverse(nd, path, link) {
574 /* Enable all helpers adjacent to the path first */
575 ret = coresight_enable_helpers(csdev, mode, sink_data);
579 * ETF devices are tricky... They can be a link or a sink,
580 * depending on how they are configured. If an ETF has been
581 * "activated" it will be configured as a sink, otherwise
582 * go ahead with the link configuration.
584 if (type == CORESIGHT_DEV_TYPE_LINKSINK)
585 type = (csdev == coresight_get_sink(path)) ?
586 CORESIGHT_DEV_TYPE_SINK :
587 CORESIGHT_DEV_TYPE_LINK;
590 case CORESIGHT_DEV_TYPE_SINK:
591 ret = coresight_enable_sink(csdev, mode, sink_data);
593 * Sink is the first component turned on. If we
594 * failed to enable the sink, there are no components
595 * that need disabling. Disabling the path here
596 * would mean we could disrupt an existing session.
601 case CORESIGHT_DEV_TYPE_SOURCE:
602 /* sources are enabled from either sysFS or Perf */
604 case CORESIGHT_DEV_TYPE_LINK:
605 parent = list_prev_entry(nd, link)->csdev;
606 child = list_next_entry(nd, link)->csdev;
607 ret = coresight_enable_link(csdev, parent, child);
619 coresight_disable_path_from(path, nd);
623 struct coresight_device *coresight_get_sink(struct list_head *path)
625 struct coresight_device *csdev;
630 csdev = list_last_entry(path, struct coresight_node, link)->csdev;
631 if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
632 csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
638 static struct coresight_device *
639 coresight_find_enabled_sink(struct coresight_device *csdev)
642 struct coresight_device *sink = NULL;
644 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
645 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
650 * Recursively explore each port found on this element.
652 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
653 struct coresight_device *child_dev;
655 child_dev = csdev->pdata->out_conns[i]->dest_dev;
657 sink = coresight_find_enabled_sink(child_dev);
666 * coresight_get_enabled_sink - returns the first enabled sink using
667 * connection based search starting from the source reference
669 * @source: Coresight source device reference
671 struct coresight_device *
672 coresight_get_enabled_sink(struct coresight_device *source)
677 return coresight_find_enabled_sink(source);
680 static int coresight_sink_by_id(struct device *dev, const void *data)
682 struct coresight_device *csdev = to_coresight_device(dev);
685 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
686 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
691 * See function etm_perf_add_symlink_sink() to know where
694 hash = (unsigned long)csdev->ea->var;
696 if ((u32)hash == *(u32 *)data)
704 * coresight_get_sink_by_id - returns the sink that matches the id
705 * @id: Id of the sink to match
707 * The name of a sink is unique, whether it is found on the AMBA bus or
708 * otherwise. As such the hash of that name can easily be used to identify
711 struct coresight_device *coresight_get_sink_by_id(u32 id)
713 struct device *dev = NULL;
715 dev = bus_find_device(&coresight_bustype, NULL, &id,
716 coresight_sink_by_id);
718 return dev ? to_coresight_device(dev) : NULL;
722 * coresight_get_ref- Helper function to increase reference count to module
725 * @csdev: The coresight device to get a reference on.
727 * Return true in successful case and power up the device.
728 * Return false when failed to get reference of module.
730 static inline bool coresight_get_ref(struct coresight_device *csdev)
732 struct device *dev = csdev->dev.parent;
734 /* Make sure the driver can't be removed */
735 if (!try_module_get(dev->driver->owner))
737 /* Make sure the device can't go away */
739 pm_runtime_get_sync(dev);
744 * coresight_put_ref- Helper function to decrease reference count to module
745 * and device. Power off the device.
747 * @csdev: The coresight device to decrement a reference from.
749 static inline void coresight_put_ref(struct coresight_device *csdev)
751 struct device *dev = csdev->dev.parent;
755 module_put(dev->driver->owner);
759 * coresight_grab_device - Power up this device and any of the helper
760 * devices connected to it for trace operation. Since the helper devices
761 * don't appear on the trace path, they should be handled along with the
764 static int coresight_grab_device(struct coresight_device *csdev)
768 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
769 struct coresight_device *child;
771 child = csdev->pdata->out_conns[i]->dest_dev;
772 if (child && coresight_is_helper(child))
773 if (!coresight_get_ref(child))
776 if (coresight_get_ref(csdev))
779 for (i--; i >= 0; i--) {
780 struct coresight_device *child;
782 child = csdev->pdata->out_conns[i]->dest_dev;
783 if (child && coresight_is_helper(child))
784 coresight_put_ref(child);
790 * coresight_drop_device - Release this device and any of the helper
791 * devices connected to it.
793 static void coresight_drop_device(struct coresight_device *csdev)
797 coresight_put_ref(csdev);
798 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
799 struct coresight_device *child;
801 child = csdev->pdata->out_conns[i]->dest_dev;
802 if (child && coresight_is_helper(child))
803 coresight_put_ref(child);
808 * _coresight_build_path - recursively build a path from a @csdev to a sink.
809 * @csdev: The device to start from.
810 * @sink: The final sink we want in this path.
811 * @path: The list to add devices to.
813 * The tree of Coresight device is traversed until an activated sink is
814 * found. From there the sink is added to the list along with all the
815 * devices that led to that point - the end result is a list from source
816 * to sink. In that list the source is the first device and the sink the
819 static int _coresight_build_path(struct coresight_device *csdev,
820 struct coresight_device *sink,
821 struct list_head *path)
825 struct coresight_node *node;
827 /* An activated sink has been found. Enqueue the element */
831 if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) &&
832 sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) {
833 if (_coresight_build_path(sink, sink, path) == 0) {
839 /* Not a sink - recursively explore each port found on this element */
840 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
841 struct coresight_device *child_dev;
843 child_dev = csdev->pdata->out_conns[i]->dest_dev;
845 _coresight_build_path(child_dev, sink, path) == 0) {
856 * A path from this element to a sink has been found. The elements
857 * leading to the sink are already enqueued, all that is left to do
858 * is tell the PM runtime core we need this element and add a node
861 ret = coresight_grab_device(csdev);
865 node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
870 list_add(&node->link, path);
875 struct list_head *coresight_build_path(struct coresight_device *source,
876 struct coresight_device *sink)
878 struct list_head *path;
882 return ERR_PTR(-EINVAL);
884 path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
886 return ERR_PTR(-ENOMEM);
888 INIT_LIST_HEAD(path);
890 rc = _coresight_build_path(source, sink, path);
900 * coresight_release_path - release a previously built path.
901 * @path: the path to release.
903 * Go through all the elements of a path and 1) removed it from the list and
904 * 2) free the memory allocated for each node.
906 void coresight_release_path(struct list_head *path)
908 struct coresight_device *csdev;
909 struct coresight_node *nd, *next;
911 list_for_each_entry_safe(nd, next, path, link) {
914 coresight_drop_device(csdev);
922 /* return true if the device is a suitable type for a default sink */
923 static inline bool coresight_is_def_sink_type(struct coresight_device *csdev)
925 /* sink & correct subtype */
926 if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
927 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) &&
928 (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER))
934 * coresight_select_best_sink - return the best sink for use as default from
937 * @sink: current best sink.
938 * @depth: search depth where current sink was found.
939 * @new_sink: new sink for comparison with current sink.
940 * @new_depth: search depth where new sink was found.
942 * Sinks prioritised according to coresight_dev_subtype_sink, with only
943 * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used.
945 * Where two sinks of equal priority are found, the sink closest to the
946 * source is used (smallest search depth).
948 * return @new_sink & update @depth if better than @sink, else return @sink.
950 static struct coresight_device *
951 coresight_select_best_sink(struct coresight_device *sink, int *depth,
952 struct coresight_device *new_sink, int new_depth)
957 /* first found at this level */
959 } else if (new_sink->subtype.sink_subtype >
960 sink->subtype.sink_subtype) {
961 /* found better sink */
963 } else if ((new_sink->subtype.sink_subtype ==
964 sink->subtype.sink_subtype) &&
965 (*depth > new_depth)) {
966 /* found same but closer sink */
972 return update ? new_sink : sink;
976 * coresight_find_sink - recursive function to walk trace connections from
977 * source to find a suitable default sink.
979 * @csdev: source / current device to check.
980 * @depth: [in] search depth of calling dev, [out] depth of found sink.
982 * This will walk the connection path from a source (ETM) till a suitable
983 * sink is encountered and return that sink to the original caller.
985 * If current device is a plain sink return that & depth, otherwise recursively
986 * call child connections looking for a sink. Select best possible using
987 * coresight_select_best_sink.
989 * return best sink found, or NULL if not found at this node or child nodes.
991 static struct coresight_device *
992 coresight_find_sink(struct coresight_device *csdev, int *depth)
994 int i, curr_depth = *depth + 1, found_depth = 0;
995 struct coresight_device *found_sink = NULL;
997 if (coresight_is_def_sink_type(csdev)) {
998 found_depth = curr_depth;
1000 if (csdev->type == CORESIGHT_DEV_TYPE_SINK)
1001 goto return_def_sink;
1002 /* look past LINKSINK for something better */
1006 * Not a sink we want - or possible child sink may be better.
1007 * recursively explore each port found on this element.
1009 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
1010 struct coresight_device *child_dev, *sink = NULL;
1011 int child_depth = curr_depth;
1013 child_dev = csdev->pdata->out_conns[i]->dest_dev;
1015 sink = coresight_find_sink(child_dev, &child_depth);
1018 found_sink = coresight_select_best_sink(found_sink,
1025 /* return found sink and depth */
1027 *depth = found_depth;
1032 * coresight_find_default_sink: Find a sink suitable for use as a
1035 * @csdev: starting source to find a connected sink.
1037 * Walks connections graph looking for a suitable sink to enable for the
1038 * supplied source. Uses CoreSight device subtypes and distance from source
1039 * to select the best sink.
1041 * If a sink is found, then the default sink for this device is set and
1042 * will be automatically used in future.
1044 * Used in cases where the CoreSight user (perf / sysfs) has not selected a
1047 struct coresight_device *
1048 coresight_find_default_sink(struct coresight_device *csdev)
1052 /* look for a default sink if we have not found for this device */
1053 if (!csdev->def_sink) {
1054 if (coresight_is_percpu_source(csdev))
1055 csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev));
1056 if (!csdev->def_sink)
1057 csdev->def_sink = coresight_find_sink(csdev, &depth);
1059 return csdev->def_sink;
1062 static int coresight_remove_sink_ref(struct device *dev, void *data)
1064 struct coresight_device *sink = data;
1065 struct coresight_device *source = to_coresight_device(dev);
1067 if (source->def_sink == sink)
1068 source->def_sink = NULL;
1073 * coresight_clear_default_sink: Remove all default sink references to the
1076 * If supplied device is a sink, then check all the bus devices and clear
1077 * out all the references to this sink from the coresight_device def_sink
1080 * @csdev: coresight sink - remove references to this from all sources.
1082 static void coresight_clear_default_sink(struct coresight_device *csdev)
1084 if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||
1085 (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) {
1086 bus_for_each_dev(&coresight_bustype, NULL, csdev,
1087 coresight_remove_sink_ref);
1091 /** coresight_validate_source - make sure a source has the right credentials
1092 * @csdev: the device structure for a source.
1093 * @function: the function this was called from.
1095 * Assumes the coresight_mutex is held.
1097 static int coresight_validate_source(struct coresight_device *csdev,
1098 const char *function)
1103 subtype = csdev->subtype.source_subtype;
1105 if (type != CORESIGHT_DEV_TYPE_SOURCE) {
1106 dev_err(&csdev->dev, "wrong device type in %s\n", function);
1110 if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
1111 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE &&
1112 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM &&
1113 subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS) {
1114 dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
1121 int coresight_enable(struct coresight_device *csdev)
1124 struct coresight_device *sink;
1125 struct list_head *path;
1126 enum coresight_dev_subtype_source subtype;
1129 subtype = csdev->subtype.source_subtype;
1131 mutex_lock(&coresight_mutex);
1133 ret = coresight_validate_source(csdev, __func__);
1137 if (csdev->enable) {
1139 * There could be multiple applications driving the software
1140 * source. So keep the refcount for each such user when the
1141 * source is already enabled.
1143 if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
1144 atomic_inc(&csdev->refcnt);
1148 sink = coresight_get_enabled_sink(csdev);
1154 path = coresight_build_path(csdev, sink);
1156 pr_err("building path(s) failed\n");
1157 ret = PTR_ERR(path);
1161 ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
1165 ret = coresight_enable_source(csdev, CS_MODE_SYSFS, NULL);
1170 case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
1172 * When working from sysFS it is important to keep track
1173 * of the paths that were created so that they can be
1174 * undone in 'coresight_disable()'. Since there can only
1175 * be a single session per tracer (when working from sysFS)
1176 * a per-cpu variable will do just fine.
1178 cpu = source_ops(csdev)->cpu_id(csdev);
1179 per_cpu(tracer_path, cpu) = path;
1181 case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
1182 case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
1183 case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
1185 * Use the hash of source's device name as ID
1186 * and map the ID to the pointer of the path.
1188 hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
1189 ret = idr_alloc_u32(&path_idr, path, &hash, hash, GFP_KERNEL);
1194 /* We can't be here */
1199 mutex_unlock(&coresight_mutex);
1203 coresight_disable_path(path);
1206 coresight_release_path(path);
1209 EXPORT_SYMBOL_GPL(coresight_enable);
1211 void coresight_disable(struct coresight_device *csdev)
1214 struct list_head *path = NULL;
1217 mutex_lock(&coresight_mutex);
1219 ret = coresight_validate_source(csdev, __func__);
1223 if (!csdev->enable || !coresight_disable_source_sysfs(csdev, NULL))
1226 switch (csdev->subtype.source_subtype) {
1227 case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
1228 cpu = source_ops(csdev)->cpu_id(csdev);
1229 path = per_cpu(tracer_path, cpu);
1230 per_cpu(tracer_path, cpu) = NULL;
1232 case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
1233 case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
1234 case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
1235 hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
1236 /* Find the path by the hash. */
1237 path = idr_find(&path_idr, hash);
1239 pr_err("Path is not found for %s\n", dev_name(&csdev->dev));
1242 idr_remove(&path_idr, hash);
1245 /* We can't be here */
1249 coresight_disable_path(path);
1250 coresight_release_path(path);
1253 mutex_unlock(&coresight_mutex);
1255 EXPORT_SYMBOL_GPL(coresight_disable);
1257 static ssize_t enable_sink_show(struct device *dev,
1258 struct device_attribute *attr, char *buf)
1260 struct coresight_device *csdev = to_coresight_device(dev);
1262 return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
1265 static ssize_t enable_sink_store(struct device *dev,
1266 struct device_attribute *attr,
1267 const char *buf, size_t size)
1271 struct coresight_device *csdev = to_coresight_device(dev);
1273 ret = kstrtoul(buf, 10, &val);
1278 csdev->activated = true;
1280 csdev->activated = false;
1285 static DEVICE_ATTR_RW(enable_sink);
1287 static ssize_t enable_source_show(struct device *dev,
1288 struct device_attribute *attr, char *buf)
1290 struct coresight_device *csdev = to_coresight_device(dev);
1292 return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
1295 static ssize_t enable_source_store(struct device *dev,
1296 struct device_attribute *attr,
1297 const char *buf, size_t size)
1301 struct coresight_device *csdev = to_coresight_device(dev);
1303 ret = kstrtoul(buf, 10, &val);
1308 ret = coresight_enable(csdev);
1312 coresight_disable(csdev);
1317 static DEVICE_ATTR_RW(enable_source);
1319 static struct attribute *coresight_sink_attrs[] = {
1320 &dev_attr_enable_sink.attr,
1323 ATTRIBUTE_GROUPS(coresight_sink);
1325 static struct attribute *coresight_source_attrs[] = {
1326 &dev_attr_enable_source.attr,
1329 ATTRIBUTE_GROUPS(coresight_source);
1331 static struct device_type coresight_dev_type[] = {
1334 .groups = coresight_sink_groups,
1341 .groups = coresight_sink_groups,
1345 .groups = coresight_source_groups,
1351 /* Ensure the enum matches the names and groups */
1352 static_assert(ARRAY_SIZE(coresight_dev_type) == CORESIGHT_DEV_TYPE_MAX);
1354 static void coresight_device_release(struct device *dev)
1356 struct coresight_device *csdev = to_coresight_device(dev);
1358 fwnode_handle_put(csdev->dev.fwnode);
1362 static int coresight_orphan_match(struct device *dev, void *data)
1365 bool still_orphan = false;
1366 struct coresight_device *dst_csdev = data;
1367 struct coresight_device *src_csdev = to_coresight_device(dev);
1368 struct coresight_connection *conn;
1369 bool fixup_self = (src_csdev == dst_csdev);
1371 /* Move on to another component if no connection is orphan */
1372 if (!src_csdev->orphan)
1375 * Circle through all the connections of that component. If we find
1376 * an orphan connection whose name matches @dst_csdev, link it.
1378 for (i = 0; i < src_csdev->pdata->nr_outconns; i++) {
1379 conn = src_csdev->pdata->out_conns[i];
1381 /* Skip the port if it's already connected. */
1386 * If we are at the "new" device, which triggered this search,
1387 * we must find the remote device from the fwnode in the
1391 dst_csdev = coresight_find_csdev_by_fwnode(
1394 /* Does it match this newly added device? */
1395 if (dst_csdev && conn->dest_fwnode == dst_csdev->dev.fwnode) {
1396 ret = coresight_make_links(src_csdev, conn, dst_csdev);
1401 * Install the device connection. This also indicates that
1402 * the links are operational on both ends.
1404 conn->dest_dev = dst_csdev;
1405 conn->src_dev = src_csdev;
1407 ret = coresight_add_in_conn(conn);
1411 /* This component still has an orphan */
1412 still_orphan = true;
1416 src_csdev->orphan = still_orphan;
1419 * Returning '0' in case we didn't encounter any error,
1420 * ensures that all known component on the bus will be checked.
1425 static int coresight_fixup_orphan_conns(struct coresight_device *csdev)
1427 return bus_for_each_dev(&coresight_bustype, NULL,
1428 csdev, coresight_orphan_match);
1431 /* coresight_remove_conns - Remove other device's references to this device */
1432 static void coresight_remove_conns(struct coresight_device *csdev)
1435 struct coresight_connection *conn;
1438 * Remove the input connection references from the destination device
1439 * for each output connection.
1441 for (i = 0; i < csdev->pdata->nr_outconns; i++) {
1442 conn = csdev->pdata->out_conns[i];
1443 if (!conn->dest_dev)
1446 for (j = 0; j < conn->dest_dev->pdata->nr_inconns; ++j)
1447 if (conn->dest_dev->pdata->in_conns[j] == conn) {
1448 conn->dest_dev->pdata->in_conns[j] = NULL;
1454 * For all input connections, remove references to this device.
1455 * Connection objects are shared so modifying this device's input
1456 * connections affects the other device's output connection.
1458 for (i = 0; i < csdev->pdata->nr_inconns; ++i) {
1459 conn = csdev->pdata->in_conns[i];
1460 /* Input conns array is sparse */
1464 conn->src_dev->orphan = true;
1465 coresight_remove_links(conn->src_dev, conn);
1466 conn->dest_dev = NULL;
1471 * coresight_timeout - loop until a bit has changed to a specific register
1473 * @csa: coresight device access for the device
1474 * @offset: Offset of the register from the base of the device.
1475 * @position: the position of the bit of interest.
1476 * @value: the value the bit should have.
1478 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
1479 * TIMEOUT_US has elapsed, which ever happens first.
1481 int coresight_timeout(struct csdev_access *csa, u32 offset,
1482 int position, int value)
1487 for (i = TIMEOUT_US; i > 0; i--) {
1488 val = csdev_access_read32(csa, offset);
1489 /* waiting on the bit to go from 0 to 1 */
1491 if (val & BIT(position))
1493 /* waiting on the bit to go from 1 to 0 */
1495 if (!(val & BIT(position)))
1500 * Delay is arbitrary - the specification doesn't say how long
1501 * we are expected to wait. Extra check required to make sure
1502 * we don't wait needlessly on the last iteration.
1510 EXPORT_SYMBOL_GPL(coresight_timeout);
1512 u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)
1514 return csdev_access_relaxed_read32(&csdev->access, offset);
1517 u32 coresight_read32(struct coresight_device *csdev, u32 offset)
1519 return csdev_access_read32(&csdev->access, offset);
1522 void coresight_relaxed_write32(struct coresight_device *csdev,
1523 u32 val, u32 offset)
1525 csdev_access_relaxed_write32(&csdev->access, val, offset);
1528 void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)
1530 csdev_access_write32(&csdev->access, val, offset);
1533 u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset)
1535 return csdev_access_relaxed_read64(&csdev->access, offset);
1538 u64 coresight_read64(struct coresight_device *csdev, u32 offset)
1540 return csdev_access_read64(&csdev->access, offset);
1543 void coresight_relaxed_write64(struct coresight_device *csdev,
1544 u64 val, u32 offset)
1546 csdev_access_relaxed_write64(&csdev->access, val, offset);
1549 void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
1551 csdev_access_write64(&csdev->access, val, offset);
1555 * coresight_release_platform_data: Release references to the devices connected
1556 * to the output port of this device.
1558 void coresight_release_platform_data(struct coresight_device *csdev,
1560 struct coresight_platform_data *pdata)
1563 struct coresight_connection **conns = pdata->out_conns;
1565 for (i = 0; i < pdata->nr_outconns; i++) {
1566 /* If we have made the links, remove them now */
1567 if (csdev && conns[i]->dest_dev)
1568 coresight_remove_links(csdev, conns[i]);
1570 * Drop the refcount and clear the handle as this device
1573 fwnode_handle_put(conns[i]->dest_fwnode);
1574 conns[i]->dest_fwnode = NULL;
1575 devm_kfree(dev, conns[i]);
1577 devm_kfree(dev, pdata->out_conns);
1578 devm_kfree(dev, pdata->in_conns);
1579 devm_kfree(dev, pdata);
1581 coresight_remove_conns_sysfs_group(csdev);
1584 struct coresight_device *coresight_register(struct coresight_desc *desc)
1587 struct coresight_device *csdev;
1588 bool registered = false;
1590 csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
1596 csdev->pdata = desc->pdata;
1598 csdev->type = desc->type;
1599 csdev->subtype = desc->subtype;
1600 csdev->ops = desc->ops;
1601 csdev->access = desc->access;
1602 csdev->orphan = true;
1604 csdev->dev.type = &coresight_dev_type[desc->type];
1605 csdev->dev.groups = desc->groups;
1606 csdev->dev.parent = desc->dev;
1607 csdev->dev.release = coresight_device_release;
1608 csdev->dev.bus = &coresight_bustype;
1610 * Hold the reference to our parent device. This will be
1611 * dropped only in coresight_device_release().
1613 csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
1614 dev_set_name(&csdev->dev, "%s", desc->name);
1617 * Make sure the device registration and the connection fixup
1618 * are synchronised, so that we don't see uninitialised devices
1619 * on the coresight bus while trying to resolve the connections.
1621 mutex_lock(&coresight_mutex);
1623 ret = device_register(&csdev->dev);
1625 put_device(&csdev->dev);
1627 * All resources are free'd explicitly via
1628 * coresight_device_release(), triggered from put_device().
1633 if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
1634 csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
1635 ret = etm_perf_add_symlink_sink(csdev);
1638 device_unregister(&csdev->dev);
1640 * As with the above, all resources are free'd
1641 * explicitly via coresight_device_release() triggered
1642 * from put_device(), which is in turn called from
1643 * function device_unregister().
1648 /* Device is now registered */
1651 ret = coresight_create_conns_sysfs_group(csdev);
1653 ret = coresight_fixup_orphan_conns(csdev);
1656 mutex_unlock(&coresight_mutex);
1659 if (cti_assoc_ops && cti_assoc_ops->add)
1660 cti_assoc_ops->add(csdev);
1664 /* Unregister the device if needed */
1666 coresight_unregister(csdev);
1667 return ERR_PTR(ret);
1671 /* Cleanup the connection information */
1672 coresight_release_platform_data(NULL, desc->dev, desc->pdata);
1673 return ERR_PTR(ret);
1675 EXPORT_SYMBOL_GPL(coresight_register);
1677 void coresight_unregister(struct coresight_device *csdev)
1679 etm_perf_del_symlink_sink(csdev);
1680 /* Remove references of that device in the topology */
1681 if (cti_assoc_ops && cti_assoc_ops->remove)
1682 cti_assoc_ops->remove(csdev);
1683 coresight_remove_conns(csdev);
1684 coresight_clear_default_sink(csdev);
1685 coresight_release_platform_data(csdev, csdev->dev.parent, csdev->pdata);
1686 device_unregister(&csdev->dev);
1688 EXPORT_SYMBOL_GPL(coresight_unregister);
1692 * coresight_search_device_idx - Search the fwnode handle of a device
1693 * in the given dev_idx list. Must be called with the coresight_mutex held.
1695 * Returns the index of the entry, when found. Otherwise, -ENOENT.
1697 static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
1698 struct fwnode_handle *fwnode)
1702 for (i = 0; i < dict->nr_idx; i++)
1703 if (dict->fwnode_list[i] == fwnode)
1708 static bool coresight_compare_type(enum coresight_dev_type type_a,
1709 union coresight_dev_subtype subtype_a,
1710 enum coresight_dev_type type_b,
1711 union coresight_dev_subtype subtype_b)
1713 if (type_a != type_b)
1717 case CORESIGHT_DEV_TYPE_SINK:
1718 return subtype_a.sink_subtype == subtype_b.sink_subtype;
1719 case CORESIGHT_DEV_TYPE_LINK:
1720 return subtype_a.link_subtype == subtype_b.link_subtype;
1721 case CORESIGHT_DEV_TYPE_LINKSINK:
1722 return subtype_a.link_subtype == subtype_b.link_subtype &&
1723 subtype_a.sink_subtype == subtype_b.sink_subtype;
1724 case CORESIGHT_DEV_TYPE_SOURCE:
1725 return subtype_a.source_subtype == subtype_b.source_subtype;
1726 case CORESIGHT_DEV_TYPE_HELPER:
1727 return subtype_a.helper_subtype == subtype_b.helper_subtype;
1733 struct coresight_device *
1734 coresight_find_input_type(struct coresight_platform_data *pdata,
1735 enum coresight_dev_type type,
1736 union coresight_dev_subtype subtype)
1739 struct coresight_connection *conn;
1741 for (i = 0; i < pdata->nr_inconns; ++i) {
1742 conn = pdata->in_conns[i];
1744 coresight_compare_type(type, subtype, conn->src_dev->type,
1745 conn->src_dev->subtype))
1746 return conn->src_dev;
1750 EXPORT_SYMBOL_GPL(coresight_find_input_type);
1752 struct coresight_device *
1753 coresight_find_output_type(struct coresight_platform_data *pdata,
1754 enum coresight_dev_type type,
1755 union coresight_dev_subtype subtype)
1758 struct coresight_connection *conn;
1760 for (i = 0; i < pdata->nr_outconns; ++i) {
1761 conn = pdata->out_conns[i];
1762 if (conn->dest_dev &&
1763 coresight_compare_type(type, subtype, conn->dest_dev->type,
1764 conn->dest_dev->subtype))
1765 return conn->dest_dev;
1769 EXPORT_SYMBOL_GPL(coresight_find_output_type);
1771 bool coresight_loses_context_with_cpu(struct device *dev)
1773 return fwnode_property_present(dev_fwnode(dev),
1774 "arm,coresight-loses-context-with-cpu");
1776 EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu);
1779 * coresight_alloc_device_name - Get an index for a given device in the
1780 * device index list specific to a driver. An index is allocated for a
1781 * device and is tracked with the fwnode_handle to prevent allocating
1782 * duplicate indices for the same device (e.g, if we defer probing of
1783 * a device due to dependencies), in case the index is requested again.
1785 char *coresight_alloc_device_name(struct coresight_dev_list *dict,
1790 struct fwnode_handle **list;
1792 mutex_lock(&coresight_mutex);
1794 idx = coresight_search_device_idx(dict, dev_fwnode(dev));
1796 /* Make space for the new entry */
1798 list = krealloc_array(dict->fwnode_list,
1799 idx + 1, sizeof(*dict->fwnode_list),
1801 if (ZERO_OR_NULL_PTR(list)) {
1806 list[idx] = dev_fwnode(dev);
1807 dict->fwnode_list = list;
1808 dict->nr_idx = idx + 1;
1811 name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
1813 mutex_unlock(&coresight_mutex);
1816 EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
1818 struct bus_type coresight_bustype = {
1819 .name = "coresight",
1822 static int __init coresight_init(void)
1826 ret = bus_register(&coresight_bustype);
1830 ret = etm_perf_init();
1832 goto exit_bus_unregister;
1834 /* initialise the coresight syscfg API */
1840 exit_bus_unregister:
1841 bus_unregister(&coresight_bustype);
1845 static void __exit coresight_exit(void)
1849 bus_unregister(&coresight_bustype);
1852 module_init(coresight_init);
1853 module_exit(coresight_exit);
1855 MODULE_LICENSE("GPL v2");
1856 MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1857 MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
1858 MODULE_DESCRIPTION("Arm CoreSight tracer driver");