1 /* Copyright (c) 2012, The Linux Foundation. All rights reserved.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/export.h>
20 #include <linux/slab.h>
21 #include <linux/mutex.h>
22 #include <linux/clk.h>
23 #include <linux/coresight.h>
24 #include <linux/of_platform.h>
25 #include <linux/delay.h>
26 #include <linux/pm_runtime.h>
28 #include "coresight-priv.h"
30 static DEFINE_MUTEX(coresight_mutex
);
33 * struct coresight_node - elements of a path, from source to sink
34 * @csdev: Address of an element.
35 * @link: hook to the list.
37 struct coresight_node
{
38 struct coresight_device
*csdev
;
39 struct list_head link
;
43 * When operating Coresight drivers from the sysFS interface, only a single
44 * path can exist from a tracer (associated to a CPU) to a sink.
46 static DEFINE_PER_CPU(struct list_head
*, sysfs_path
);
48 static int coresight_id_match(struct device
*dev
, void *data
)
50 int trace_id
, i_trace_id
;
51 struct coresight_device
*csdev
, *i_csdev
;
54 i_csdev
= to_coresight_device(dev
);
57 * No need to care about oneself and components that are not
58 * sources or not enabled
60 if (i_csdev
== csdev
|| !i_csdev
->enable
||
61 i_csdev
->type
!= CORESIGHT_DEV_TYPE_SOURCE
)
64 /* Get the source ID for both compoment */
65 trace_id
= source_ops(csdev
)->trace_id(csdev
);
66 i_trace_id
= source_ops(i_csdev
)->trace_id(i_csdev
);
68 /* All you need is one */
69 if (trace_id
== i_trace_id
)
75 static int coresight_source_is_unique(struct coresight_device
*csdev
)
77 int trace_id
= source_ops(csdev
)->trace_id(csdev
);
79 /* this shouldn't happen */
83 return !bus_for_each_dev(&coresight_bustype
, NULL
,
84 csdev
, coresight_id_match
);
87 static int coresight_find_link_inport(struct coresight_device
*csdev
,
88 struct coresight_device
*parent
)
91 struct coresight_connection
*conn
;
93 for (i
= 0; i
< parent
->nr_outport
; i
++) {
94 conn
= &parent
->conns
[i
];
95 if (conn
->child_dev
== csdev
)
96 return conn
->child_port
;
99 dev_err(&csdev
->dev
, "couldn't find inport, parent: %s, child: %s\n",
100 dev_name(&parent
->dev
), dev_name(&csdev
->dev
));
105 static int coresight_find_link_outport(struct coresight_device
*csdev
,
106 struct coresight_device
*child
)
109 struct coresight_connection
*conn
;
111 for (i
= 0; i
< csdev
->nr_outport
; i
++) {
112 conn
= &csdev
->conns
[i
];
113 if (conn
->child_dev
== child
)
114 return conn
->outport
;
117 dev_err(&csdev
->dev
, "couldn't find outport, parent: %s, child: %s\n",
118 dev_name(&csdev
->dev
), dev_name(&child
->dev
));
123 static int coresight_enable_sink(struct coresight_device
*csdev
, u32 mode
)
127 if (!csdev
->enable
) {
128 if (sink_ops(csdev
)->enable
) {
129 ret
= sink_ops(csdev
)->enable(csdev
, mode
);
133 csdev
->enable
= true;
136 atomic_inc(csdev
->refcnt
);
141 static void coresight_disable_sink(struct coresight_device
*csdev
)
143 if (atomic_dec_return(csdev
->refcnt
) == 0) {
144 if (sink_ops(csdev
)->disable
) {
145 sink_ops(csdev
)->disable(csdev
);
146 csdev
->enable
= false;
151 static int coresight_enable_link(struct coresight_device
*csdev
,
152 struct coresight_device
*parent
,
153 struct coresight_device
*child
)
157 int refport
, inport
, outport
;
159 if (!parent
|| !child
)
162 inport
= coresight_find_link_inport(csdev
, parent
);
163 outport
= coresight_find_link_outport(csdev
, child
);
164 link_subtype
= csdev
->subtype
.link_subtype
;
166 if (link_subtype
== CORESIGHT_DEV_SUBTYPE_LINK_MERG
)
168 else if (link_subtype
== CORESIGHT_DEV_SUBTYPE_LINK_SPLIT
)
173 if (atomic_inc_return(&csdev
->refcnt
[refport
]) == 1) {
174 if (link_ops(csdev
)->enable
) {
175 ret
= link_ops(csdev
)->enable(csdev
, inport
, outport
);
181 csdev
->enable
= true;
186 static void coresight_disable_link(struct coresight_device
*csdev
,
187 struct coresight_device
*parent
,
188 struct coresight_device
*child
)
192 int refport
, inport
, outport
;
194 if (!parent
|| !child
)
197 inport
= coresight_find_link_inport(csdev
, parent
);
198 outport
= coresight_find_link_outport(csdev
, child
);
199 link_subtype
= csdev
->subtype
.link_subtype
;
201 if (link_subtype
== CORESIGHT_DEV_SUBTYPE_LINK_MERG
) {
203 nr_conns
= csdev
->nr_inport
;
204 } else if (link_subtype
== CORESIGHT_DEV_SUBTYPE_LINK_SPLIT
) {
206 nr_conns
= csdev
->nr_outport
;
212 if (atomic_dec_return(&csdev
->refcnt
[refport
]) == 0) {
213 if (link_ops(csdev
)->disable
)
214 link_ops(csdev
)->disable(csdev
, inport
, outport
);
217 for (i
= 0; i
< nr_conns
; i
++)
218 if (atomic_read(&csdev
->refcnt
[i
]) != 0)
221 csdev
->enable
= false;
224 static int coresight_enable_source(struct coresight_device
*csdev
, u32 mode
)
228 if (!coresight_source_is_unique(csdev
)) {
229 dev_warn(&csdev
->dev
, "traceID %d not unique\n",
230 source_ops(csdev
)->trace_id(csdev
));
234 if (!csdev
->enable
) {
235 if (source_ops(csdev
)->enable
) {
236 ret
= source_ops(csdev
)->enable(csdev
, NULL
, mode
);
240 csdev
->enable
= true;
243 atomic_inc(csdev
->refcnt
);
248 static void coresight_disable_source(struct coresight_device
*csdev
)
250 if (atomic_dec_return(csdev
->refcnt
) == 0) {
251 if (source_ops(csdev
)->disable
) {
252 source_ops(csdev
)->disable(csdev
);
253 csdev
->enable
= false;
258 void coresight_disable_path(struct list_head
*path
)
260 struct coresight_node
*nd
;
261 struct coresight_device
*csdev
, *parent
, *child
;
263 list_for_each_entry(nd
, path
, link
) {
266 switch (csdev
->type
) {
267 case CORESIGHT_DEV_TYPE_SINK
:
268 case CORESIGHT_DEV_TYPE_LINKSINK
:
269 coresight_disable_sink(csdev
);
271 case CORESIGHT_DEV_TYPE_SOURCE
:
272 /* sources are disabled from either sysFS or Perf */
274 case CORESIGHT_DEV_TYPE_LINK
:
275 parent
= list_prev_entry(nd
, link
)->csdev
;
276 child
= list_next_entry(nd
, link
)->csdev
;
277 coresight_disable_link(csdev
, parent
, child
);
285 int coresight_enable_path(struct list_head
*path
, u32 mode
)
289 struct coresight_node
*nd
;
290 struct coresight_device
*csdev
, *parent
, *child
;
292 list_for_each_entry_reverse(nd
, path
, link
) {
295 switch (csdev
->type
) {
296 case CORESIGHT_DEV_TYPE_SINK
:
297 case CORESIGHT_DEV_TYPE_LINKSINK
:
298 ret
= coresight_enable_sink(csdev
, mode
);
302 case CORESIGHT_DEV_TYPE_SOURCE
:
303 /* sources are enabled from either sysFS or Perf */
305 case CORESIGHT_DEV_TYPE_LINK
:
306 parent
= list_prev_entry(nd
, link
)->csdev
;
307 child
= list_next_entry(nd
, link
)->csdev
;
308 ret
= coresight_enable_link(csdev
, parent
, child
);
320 coresight_disable_path(path
);
324 struct coresight_device
*coresight_get_sink(struct list_head
*path
)
326 struct coresight_device
*csdev
;
331 csdev
= list_last_entry(path
, struct coresight_node
, link
)->csdev
;
332 if (csdev
->type
!= CORESIGHT_DEV_TYPE_SINK
&&
333 csdev
->type
!= CORESIGHT_DEV_TYPE_LINKSINK
)
340 * _coresight_build_path - recursively build a path from a @csdev to a sink.
341 * @csdev: The device to start from.
342 * @path: The list to add devices to.
344 * The tree of Coresight device is traversed until an activated sink is
345 * found. From there the sink is added to the list along with all the
346 * devices that led to that point - the end result is a list from source
347 * to sink. In that list the source is the first device and the sink the
350 static int _coresight_build_path(struct coresight_device
*csdev
,
351 struct list_head
*path
)
355 struct coresight_node
*node
;
356 struct coresight_connection
*conn
;
358 /* An activated sink has been found. Enqueue the element */
359 if ((csdev
->type
== CORESIGHT_DEV_TYPE_SINK
||
360 csdev
->type
== CORESIGHT_DEV_TYPE_LINKSINK
) && csdev
->activated
)
363 /* Not a sink - recursively explore each port found on this element */
364 for (i
= 0; i
< csdev
->nr_outport
; i
++) {
365 conn
= &csdev
->conns
[i
];
366 if (_coresight_build_path(conn
->child_dev
, path
) == 0) {
377 * A path from this element to a sink has been found. The elements
378 * leading to the sink are already enqueued, all that is left to do
379 * is tell the PM runtime core we need this element and add a node
382 node
= kzalloc(sizeof(struct coresight_node
), GFP_KERNEL
);
387 list_add(&node
->link
, path
);
388 pm_runtime_get_sync(csdev
->dev
.parent
);
393 struct list_head
*coresight_build_path(struct coresight_device
*csdev
)
395 struct list_head
*path
;
397 path
= kzalloc(sizeof(struct list_head
), GFP_KERNEL
);
401 INIT_LIST_HEAD(path
);
403 if (_coresight_build_path(csdev
, path
)) {
412 * coresight_release_path - release a previously built path.
413 * @path: the path to release.
415 * Go through all the elements of a path and 1) removed it from the list and
416 * 2) free the memory allocated for each node.
418 void coresight_release_path(struct list_head
*path
)
420 struct coresight_device
*csdev
;
421 struct coresight_node
*nd
, *next
;
423 list_for_each_entry_safe(nd
, next
, path
, link
) {
426 pm_runtime_put_sync(csdev
->dev
.parent
);
435 int coresight_enable(struct coresight_device
*csdev
)
439 struct list_head
*path
;
441 mutex_lock(&coresight_mutex
);
442 if (csdev
->type
!= CORESIGHT_DEV_TYPE_SOURCE
) {
444 dev_err(&csdev
->dev
, "wrong device type in %s\n", __func__
);
450 path
= coresight_build_path(csdev
);
452 pr_err("building path(s) failed\n");
456 ret
= coresight_enable_path(path
, CS_MODE_SYSFS
);
460 ret
= coresight_enable_source(csdev
, CS_MODE_SYSFS
);
465 * When working from sysFS it is important to keep track
466 * of the paths that were created so that they can be
467 * undone in 'coresight_disable()'. Since there can only
468 * be a single session per tracer (when working from sysFS)
469 * a per-cpu variable will do just fine.
471 cpu
= source_ops(csdev
)->cpu_id(csdev
);
472 per_cpu(sysfs_path
, cpu
) = path
;
475 mutex_unlock(&coresight_mutex
);
479 coresight_disable_path(path
);
482 coresight_release_path(path
);
485 EXPORT_SYMBOL_GPL(coresight_enable
);
487 void coresight_disable(struct coresight_device
*csdev
)
490 struct list_head
*path
;
492 mutex_lock(&coresight_mutex
);
493 if (csdev
->type
!= CORESIGHT_DEV_TYPE_SOURCE
) {
494 dev_err(&csdev
->dev
, "wrong device type in %s\n", __func__
);
500 cpu
= source_ops(csdev
)->cpu_id(csdev
);
501 path
= per_cpu(sysfs_path
, cpu
);
502 coresight_disable_source(csdev
);
503 coresight_disable_path(path
);
504 coresight_release_path(path
);
505 per_cpu(sysfs_path
, cpu
) = NULL
;
508 mutex_unlock(&coresight_mutex
);
510 EXPORT_SYMBOL_GPL(coresight_disable
);
512 static ssize_t
enable_sink_show(struct device
*dev
,
513 struct device_attribute
*attr
, char *buf
)
515 struct coresight_device
*csdev
= to_coresight_device(dev
);
517 return scnprintf(buf
, PAGE_SIZE
, "%u\n", (unsigned)csdev
->activated
);
520 static ssize_t
enable_sink_store(struct device
*dev
,
521 struct device_attribute
*attr
,
522 const char *buf
, size_t size
)
526 struct coresight_device
*csdev
= to_coresight_device(dev
);
528 ret
= kstrtoul(buf
, 10, &val
);
533 csdev
->activated
= true;
535 csdev
->activated
= false;
540 static DEVICE_ATTR_RW(enable_sink
);
542 static ssize_t
enable_source_show(struct device
*dev
,
543 struct device_attribute
*attr
, char *buf
)
545 struct coresight_device
*csdev
= to_coresight_device(dev
);
547 return scnprintf(buf
, PAGE_SIZE
, "%u\n", (unsigned)csdev
->enable
);
550 static ssize_t
enable_source_store(struct device
*dev
,
551 struct device_attribute
*attr
,
552 const char *buf
, size_t size
)
556 struct coresight_device
*csdev
= to_coresight_device(dev
);
558 ret
= kstrtoul(buf
, 10, &val
);
563 ret
= coresight_enable(csdev
);
567 coresight_disable(csdev
);
572 static DEVICE_ATTR_RW(enable_source
);
574 static struct attribute
*coresight_sink_attrs
[] = {
575 &dev_attr_enable_sink
.attr
,
578 ATTRIBUTE_GROUPS(coresight_sink
);
580 static struct attribute
*coresight_source_attrs
[] = {
581 &dev_attr_enable_source
.attr
,
584 ATTRIBUTE_GROUPS(coresight_source
);
586 static struct device_type coresight_dev_type
[] = {
592 .groups
= coresight_sink_groups
,
599 .groups
= coresight_sink_groups
,
603 .groups
= coresight_source_groups
,
607 static void coresight_device_release(struct device
*dev
)
609 struct coresight_device
*csdev
= to_coresight_device(dev
);
612 kfree(csdev
->refcnt
);
616 static int coresight_orphan_match(struct device
*dev
, void *data
)
619 bool still_orphan
= false;
620 struct coresight_device
*csdev
, *i_csdev
;
621 struct coresight_connection
*conn
;
624 i_csdev
= to_coresight_device(dev
);
626 /* No need to check oneself */
627 if (csdev
== i_csdev
)
630 /* Move on to another component if no connection is orphan */
631 if (!i_csdev
->orphan
)
634 * Circle throuch all the connection of that component. If we find
635 * an orphan connection whose name matches @csdev, link it.
637 for (i
= 0; i
< i_csdev
->nr_outport
; i
++) {
638 conn
= &i_csdev
->conns
[i
];
640 /* We have found at least one orphan connection */
641 if (conn
->child_dev
== NULL
) {
642 /* Does it match this newly added device? */
643 if (!strcmp(dev_name(&csdev
->dev
), conn
->child_name
)) {
644 conn
->child_dev
= csdev
;
646 /* This component still has an orphan */
652 i_csdev
->orphan
= still_orphan
;
655 * Returning '0' ensures that all known component on the
656 * bus will be checked.
661 static void coresight_fixup_orphan_conns(struct coresight_device
*csdev
)
664 * No need to check for a return value as orphan connection(s)
665 * are hooked-up with each newly added component.
667 bus_for_each_dev(&coresight_bustype
, NULL
,
668 csdev
, coresight_orphan_match
);
672 static int coresight_name_match(struct device
*dev
, void *data
)
675 struct coresight_device
*i_csdev
;
678 i_csdev
= to_coresight_device(dev
);
680 if (to_match
&& !strcmp(to_match
, dev_name(&i_csdev
->dev
)))
686 static void coresight_fixup_device_conns(struct coresight_device
*csdev
)
689 struct device
*dev
= NULL
;
690 struct coresight_connection
*conn
;
692 for (i
= 0; i
< csdev
->nr_outport
; i
++) {
693 conn
= &csdev
->conns
[i
];
694 dev
= bus_find_device(&coresight_bustype
, NULL
,
695 (void *)conn
->child_name
,
696 coresight_name_match
);
699 conn
->child_dev
= to_coresight_device(dev
);
700 /* and put reference from 'bus_find_device()' */
703 csdev
->orphan
= true;
704 conn
->child_dev
= NULL
;
709 static int coresight_remove_match(struct device
*dev
, void *data
)
712 struct coresight_device
*csdev
, *iterator
;
713 struct coresight_connection
*conn
;
716 iterator
= to_coresight_device(dev
);
718 /* No need to check oneself */
719 if (csdev
== iterator
)
723 * Circle throuch all the connection of that component. If we find
724 * a connection whose name matches @csdev, remove it.
726 for (i
= 0; i
< iterator
->nr_outport
; i
++) {
727 conn
= &iterator
->conns
[i
];
729 if (conn
->child_dev
== NULL
)
732 if (!strcmp(dev_name(&csdev
->dev
), conn
->child_name
)) {
733 iterator
->orphan
= true;
734 conn
->child_dev
= NULL
;
735 /* No need to continue */
741 * Returning '0' ensures that all known component on the
742 * bus will be checked.
747 static void coresight_remove_conns(struct coresight_device
*csdev
)
749 bus_for_each_dev(&coresight_bustype
, NULL
,
750 csdev
, coresight_remove_match
);
754 * coresight_timeout - loop until a bit has changed to a specific state.
755 * @addr: base address of the area of interest.
756 * @offset: address of a register, starting from @addr.
757 * @position: the position of the bit of interest.
758 * @value: the value the bit should have.
760 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
761 * TIMEOUT_US has elapsed, which ever happens first.
764 int coresight_timeout(void __iomem
*addr
, u32 offset
, int position
, int value
)
769 for (i
= TIMEOUT_US
; i
> 0; i
--) {
770 val
= __raw_readl(addr
+ offset
);
771 /* waiting on the bit to go from 0 to 1 */
773 if (val
& BIT(position
))
775 /* waiting on the bit to go from 1 to 0 */
777 if (!(val
& BIT(position
)))
782 * Delay is arbitrary - the specification doesn't say how long
783 * we are expected to wait. Extra check required to make sure
784 * we don't wait needlessly on the last iteration.
793 struct bus_type coresight_bustype
= {
797 static int __init
coresight_init(void)
799 return bus_register(&coresight_bustype
);
801 postcore_initcall(coresight_init
);
803 struct coresight_device
*coresight_register(struct coresight_desc
*desc
)
809 atomic_t
*refcnts
= NULL
;
810 struct coresight_device
*csdev
;
811 struct coresight_connection
*conns
;
813 csdev
= kzalloc(sizeof(*csdev
), GFP_KERNEL
);
816 goto err_kzalloc_csdev
;
819 if (desc
->type
== CORESIGHT_DEV_TYPE_LINK
||
820 desc
->type
== CORESIGHT_DEV_TYPE_LINKSINK
) {
821 link_subtype
= desc
->subtype
.link_subtype
;
823 if (link_subtype
== CORESIGHT_DEV_SUBTYPE_LINK_MERG
)
824 nr_refcnts
= desc
->pdata
->nr_inport
;
825 else if (link_subtype
== CORESIGHT_DEV_SUBTYPE_LINK_SPLIT
)
826 nr_refcnts
= desc
->pdata
->nr_outport
;
829 refcnts
= kcalloc(nr_refcnts
, sizeof(*refcnts
), GFP_KERNEL
);
832 goto err_kzalloc_refcnts
;
835 csdev
->refcnt
= refcnts
;
837 csdev
->nr_inport
= desc
->pdata
->nr_inport
;
838 csdev
->nr_outport
= desc
->pdata
->nr_outport
;
839 conns
= kcalloc(csdev
->nr_outport
, sizeof(*conns
), GFP_KERNEL
);
842 goto err_kzalloc_conns
;
845 for (i
= 0; i
< csdev
->nr_outport
; i
++) {
846 conns
[i
].outport
= desc
->pdata
->outports
[i
];
847 conns
[i
].child_name
= desc
->pdata
->child_names
[i
];
848 conns
[i
].child_port
= desc
->pdata
->child_ports
[i
];
851 csdev
->conns
= conns
;
853 csdev
->type
= desc
->type
;
854 csdev
->subtype
= desc
->subtype
;
855 csdev
->ops
= desc
->ops
;
856 csdev
->orphan
= false;
858 csdev
->dev
.type
= &coresight_dev_type
[desc
->type
];
859 csdev
->dev
.groups
= desc
->groups
;
860 csdev
->dev
.parent
= desc
->dev
;
861 csdev
->dev
.release
= coresight_device_release
;
862 csdev
->dev
.bus
= &coresight_bustype
;
863 dev_set_name(&csdev
->dev
, "%s", desc
->pdata
->name
);
865 ret
= device_register(&csdev
->dev
);
867 goto err_device_register
;
869 mutex_lock(&coresight_mutex
);
871 coresight_fixup_device_conns(csdev
);
872 coresight_fixup_orphan_conns(csdev
);
874 mutex_unlock(&coresight_mutex
);
887 EXPORT_SYMBOL_GPL(coresight_register
);
889 void coresight_unregister(struct coresight_device
*csdev
)
891 /* Remove references of that device in the topology */
892 coresight_remove_conns(csdev
);
893 device_unregister(&csdev
->dev
);
895 EXPORT_SYMBOL_GPL(coresight_unregister
);