1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
4 */
5
6#include <linux/acpi.h>
7#include <linux/types.h>
8#include <linux/err.h>
9#include <linux/slab.h>
10#include <linux/clk.h>
11#include <linux/of.h>
12#include <linux/of_graph.h>
13#include <linux/platform_device.h>
14#include <linux/amba/bus.h>
15#include <linux/coresight.h>
16#include <linux/cpumask.h>
17#include <asm/smp_plat.h>
18
19#include "coresight-priv.h"
20
21/*
22 * Add an entry to the connection list and assign @conn's contents to it.
23 *
24 * If the output port is already assigned on this device, return -EINVAL
25 */
26struct coresight_connection *
27coresight_add_out_conn(struct device *dev,
28 struct coresight_platform_data *pdata,
29 const struct coresight_connection *new_conn)
30{
31 int i;
32 struct coresight_connection *conn;
33
34 /*
35 * Warn on any existing duplicate output port.
36 */
37 for (i = 0; i < pdata->nr_outconns; ++i) {
38 conn = pdata->out_conns[i];
39 /* Output == -1 means ignore the port for example for helpers */
40 if (conn->src_port != -1 &&
41 conn->src_port == new_conn->src_port) {
42 dev_warn(dev, "Duplicate output port %d\n",
43 conn->src_port);
44 return ERR_PTR(error: -EINVAL);
45 }
46 }
47
48 pdata->nr_outconns++;
49 pdata->out_conns =
50 devm_krealloc_array(dev, p: pdata->out_conns, new_n: pdata->nr_outconns,
51 new_size: sizeof(*pdata->out_conns), GFP_KERNEL);
52 if (!pdata->out_conns)
53 return ERR_PTR(error: -ENOMEM);
54
55 conn = devm_kmalloc(dev, size: sizeof(struct coresight_connection),
56 GFP_KERNEL);
57 if (!conn)
58 return ERR_PTR(error: -ENOMEM);
59
60 /*
61 * Copy the new connection into the allocation, save the pointer to the
62 * end of the connection array and also return it in case it needs to be
63 * used right away.
64 */
65 *conn = *new_conn;
66 pdata->out_conns[pdata->nr_outconns - 1] = conn;
67 return conn;
68}
69EXPORT_SYMBOL_GPL(coresight_add_out_conn);
70
71/*
72 * Add an input connection reference to @out_conn in the target's in_conns array
73 *
74 * @out_conn: Existing output connection to store as an input on the
75 * connection's remote device.
76 */
77int coresight_add_in_conn(struct coresight_connection *out_conn)
78{
79 int i;
80 struct device *dev = out_conn->dest_dev->dev.parent;
81 struct coresight_platform_data *pdata = out_conn->dest_dev->pdata;
82
83 for (i = 0; i < pdata->nr_inconns; ++i)
84 if (!pdata->in_conns[i]) {
85 pdata->in_conns[i] = out_conn;
86 return 0;
87 }
88
89 pdata->nr_inconns++;
90 pdata->in_conns =
91 devm_krealloc_array(dev, p: pdata->in_conns, new_n: pdata->nr_inconns,
92 new_size: sizeof(*pdata->in_conns), GFP_KERNEL);
93 if (!pdata->in_conns)
94 return -ENOMEM;
95 pdata->in_conns[pdata->nr_inconns - 1] = out_conn;
96 return 0;
97}
98EXPORT_SYMBOL_GPL(coresight_add_in_conn);
99
100static struct device *
101coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
102{
103 struct device *dev = NULL;
104
105 /*
106 * If we have a non-configurable replicator, it will be found on the
107 * platform bus.
108 */
109 dev = bus_find_device_by_fwnode(bus: &platform_bus_type, fwnode);
110 if (dev)
111 return dev;
112
113 /*
114 * We have a configurable component - circle through the AMBA bus
115 * looking for the device that matches the endpoint node.
116 */
117 return bus_find_device_by_fwnode(bus: &amba_bustype, fwnode);
118}
119
120/*
121 * Find a registered coresight device from a device fwnode.
122 * The node info is associated with the AMBA parent, but the
123 * csdev keeps a copy so iterate round the coresight bus to
124 * find the device.
125 */
126struct coresight_device *
127coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode)
128{
129 struct device *dev;
130 struct coresight_device *csdev = NULL;
131
132 dev = bus_find_device_by_fwnode(bus: &coresight_bustype, fwnode: r_fwnode);
133 if (dev) {
134 csdev = to_coresight_device(dev);
135 put_device(dev);
136 }
137 return csdev;
138}
139EXPORT_SYMBOL_GPL(coresight_find_csdev_by_fwnode);
140
141#ifdef CONFIG_OF
142static inline bool of_coresight_legacy_ep_is_input(struct device_node *ep)
143{
144 return of_property_read_bool(np: ep, propname: "slave-mode");
145}
146
147static struct device_node *of_coresight_get_port_parent(struct device_node *ep)
148{
149 struct device_node *parent = of_graph_get_port_parent(node: ep);
150
151 /*
152 * Skip one-level up to the real device node, if we
153 * are using the new bindings.
154 */
155 if (of_node_name_eq(np: parent, name: "in-ports") ||
156 of_node_name_eq(np: parent, name: "out-ports"))
157 parent = of_get_next_parent(node: parent);
158
159 return parent;
160}
161
162static inline struct device_node *
163of_coresight_get_output_ports_node(const struct device_node *node)
164{
165 return of_get_child_by_name(node, name: "out-ports");
166}
167
168static int of_coresight_get_cpu(struct device *dev)
169{
170 int cpu;
171 struct device_node *dn;
172
173 if (!dev->of_node)
174 return -ENODEV;
175
176 dn = of_parse_phandle(np: dev->of_node, phandle_name: "cpu", index: 0);
177 if (!dn)
178 return -ENODEV;
179
180 cpu = of_cpu_node_to_id(np: dn);
181 of_node_put(node: dn);
182
183 return cpu;
184}
185
186/*
187 * of_coresight_parse_endpoint : Parse the given output endpoint @ep
188 * and fill the connection information in @pdata->out_conns
189 *
190 * Parses the local port, remote device name and the remote port.
191 *
192 * Returns :
193 * 0 - If the parsing completed without any fatal errors.
194 * -Errno - Fatal error, abort the scanning.
195 */
196static int of_coresight_parse_endpoint(struct device *dev,
197 struct device_node *ep,
198 struct coresight_platform_data *pdata)
199{
200 int ret = 0;
201 struct of_endpoint endpoint, rendpoint;
202 struct device_node *rparent = NULL;
203 struct device_node *rep = NULL;
204 struct device *rdev = NULL;
205 struct fwnode_handle *rdev_fwnode;
206 struct coresight_connection conn = {};
207 struct coresight_connection *new_conn;
208
209 do {
210 /* Parse the local port details */
211 if (of_graph_parse_endpoint(node: ep, endpoint: &endpoint))
212 break;
213 /*
214 * Get a handle on the remote endpoint and the device it is
215 * attached to.
216 */
217 rep = of_graph_get_remote_endpoint(node: ep);
218 if (!rep)
219 break;
220 rparent = of_coresight_get_port_parent(ep: rep);
221 if (!rparent)
222 break;
223 if (of_graph_parse_endpoint(node: rep, endpoint: &rendpoint))
224 break;
225
226 rdev_fwnode = of_fwnode_handle(rparent);
227 /* If the remote device is not available, defer probing */
228 rdev = coresight_find_device_by_fwnode(fwnode: rdev_fwnode);
229 if (!rdev) {
230 ret = -EPROBE_DEFER;
231 break;
232 }
233
234 conn.src_port = endpoint.port;
235 /*
236 * Hold the refcount to the target device. This could be
237 * released via:
238 * 1) coresight_release_platform_data() if the probe fails or
239 * this device is unregistered.
240 * 2) While removing the target device via
241 * coresight_remove_match()
242 */
243 conn.dest_fwnode = fwnode_handle_get(fwnode: rdev_fwnode);
244 conn.dest_port = rendpoint.port;
245
246 new_conn = coresight_add_out_conn(dev, pdata, &conn);
247 if (IS_ERR_VALUE(new_conn)) {
248 fwnode_handle_put(fwnode: conn.dest_fwnode);
249 return PTR_ERR(ptr: new_conn);
250 }
251 /* Connection record updated */
252 } while (0);
253
254 of_node_put(node: rparent);
255 of_node_put(node: rep);
256 put_device(dev: rdev);
257
258 return ret;
259}
260
261static int of_get_coresight_platform_data(struct device *dev,
262 struct coresight_platform_data *pdata)
263{
264 int ret = 0;
265 struct device_node *ep = NULL;
266 const struct device_node *parent = NULL;
267 bool legacy_binding = false;
268 struct device_node *node = dev->of_node;
269
270 parent = of_coresight_get_output_ports_node(node);
271 /*
272 * If the DT uses obsoleted bindings, the ports are listed
273 * under the device and we need to filter out the input
274 * ports.
275 */
276 if (!parent) {
277 /*
278 * Avoid warnings in of_graph_get_next_endpoint()
279 * if the device doesn't have any graph connections
280 */
281 if (!of_graph_is_present(node))
282 return 0;
283 legacy_binding = true;
284 parent = node;
285 dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
286 }
287
288 /* Iterate through each output port to discover topology */
289 while ((ep = of_graph_get_next_endpoint(parent, previous: ep))) {
290 /*
291 * Legacy binding mixes input/output ports under the
292 * same parent. So, skip the input ports if we are dealing
293 * with legacy binding, as they processed with their
294 * connected output ports.
295 */
296 if (legacy_binding && of_coresight_legacy_ep_is_input(ep))
297 continue;
298
299 ret = of_coresight_parse_endpoint(dev, ep, pdata);
300 if (ret)
301 return ret;
302 }
303
304 return 0;
305}
306#else
307static inline int
308of_get_coresight_platform_data(struct device *dev,
309 struct coresight_platform_data *pdata)
310{
311 return -ENOENT;
312}
313
314static inline int of_coresight_get_cpu(struct device *dev)
315{
316 return -ENODEV;
317}
318#endif
319
320#ifdef CONFIG_ACPI
321
322#include <acpi/actypes.h>
323#include <acpi/processor.h>
324
325/* ACPI Graph _DSD UUID : "ab02a46b-74c7-45a2-bd68-f7d344ef2153" */
326static const guid_t acpi_graph_uuid = GUID_INIT(0xab02a46b, 0x74c7, 0x45a2,
327 0xbd, 0x68, 0xf7, 0xd3,
328 0x44, 0xef, 0x21, 0x53);
329/* Coresight ACPI Graph UUID : "3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd" */
330static const guid_t coresight_graph_uuid = GUID_INIT(0x3ecbc8b6, 0x1d0e, 0x4fb3,
331 0x81, 0x07, 0xe6, 0x27,
332 0xf8, 0x05, 0xc6, 0xcd);
333#define ACPI_CORESIGHT_LINK_SLAVE 0
334#define ACPI_CORESIGHT_LINK_MASTER 1
335
336static inline bool is_acpi_guid(const union acpi_object *obj)
337{
338 return (obj->type == ACPI_TYPE_BUFFER) && (obj->buffer.length == 16);
339}
340
341/*
342 * acpi_guid_matches - Checks if the given object is a GUID object and
343 * that it matches the supplied the GUID.
344 */
345static inline bool acpi_guid_matches(const union acpi_object *obj,
346 const guid_t *guid)
347{
348 return is_acpi_guid(obj) &&
349 guid_equal(u1: (guid_t *)obj->buffer.pointer, u2: guid);
350}
351
352static inline bool is_acpi_dsd_graph_guid(const union acpi_object *obj)
353{
354 return acpi_guid_matches(obj, guid: &acpi_graph_uuid);
355}
356
357static inline bool is_acpi_coresight_graph_guid(const union acpi_object *obj)
358{
359 return acpi_guid_matches(obj, guid: &coresight_graph_uuid);
360}
361
362static inline bool is_acpi_coresight_graph(const union acpi_object *obj)
363{
364 const union acpi_object *graphid, *guid, *links;
365
366 if (obj->type != ACPI_TYPE_PACKAGE ||
367 obj->package.count < 3)
368 return false;
369
370 graphid = &obj->package.elements[0];
371 guid = &obj->package.elements[1];
372 links = &obj->package.elements[2];
373
374 if (graphid->type != ACPI_TYPE_INTEGER ||
375 links->type != ACPI_TYPE_INTEGER)
376 return false;
377
378 return is_acpi_coresight_graph_guid(obj: guid);
379}
380
381/*
382 * acpi_validate_dsd_graph - Make sure the given _DSD graph conforms
383 * to the ACPI _DSD Graph specification.
384 *
385 * ACPI Devices Graph property has the following format:
386 * {
387 * Revision - Integer, must be 0
388 * NumberOfGraphs - Integer, N indicating the following list.
389 * Graph[1],
390 * ...
391 * Graph[N]
392 * }
393 *
394 * And each Graph entry has the following format:
395 * {
396 * GraphID - Integer, identifying a graph the device belongs to.
397 * UUID - UUID identifying the specification that governs
398 * this graph. (e.g, see is_acpi_coresight_graph())
399 * NumberOfLinks - Number "N" of connections on this node of the graph.
400 * Links[1]
401 * ...
402 * Links[N]
403 * }
404 *
405 * Where each "Links" entry has the following format:
406 *
407 * {
408 * SourcePortAddress - Integer
409 * DestinationPortAddress - Integer
410 * DestinationDeviceName - Reference to another device
411 * ( --- CoreSight specific extensions below ---)
412 * DirectionOfFlow - Integer 1 for output(master)
413 * 0 for input(slave)
414 * }
415 *
416 * e.g:
417 * For a Funnel device
418 *
419 * Device(MFUN) {
420 * ...
421 *
422 * Name (_DSD, Package() {
423 * // DSD Package contains tuples of { Proeprty_Type_UUID, Package() }
424 * ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), //Std. Property UUID
425 * Package() {
426 * Package(2) { "property-name", <property-value> }
427 * },
428 *
429 * ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), // ACPI Graph UUID
430 * Package() {
431 * 0, // Revision
432 * 1, // NumberOfGraphs.
433 * Package() { // Graph[0] Package
434 * 1, // GraphID
435 * // Coresight Graph UUID
436 * ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"),
437 * 3, // NumberOfLinks aka ports
438 * // Link[0]: Output_0 -> Replicator:Input_0
439 * Package () { 0, 0, \_SB_.RPL0, 1 },
440 * // Link[1]: Input_0 <- Cluster0_Funnel0:Output_0
441 * Package () { 0, 0, \_SB_.CLU0.FUN0, 0 },
442 * // Link[2]: Input_1 <- Cluster1_Funnel0:Output_0
443 * Package () { 1, 0, \_SB_.CLU1.FUN0, 0 },
444 * } // End of Graph[0] Package
445 *
446 * }, // End of ACPI Graph Property
447 * })
448 */
449static inline bool acpi_validate_dsd_graph(const union acpi_object *graph)
450{
451 int i, n;
452 const union acpi_object *rev, *nr_graphs;
453
454 /* The graph must contain at least the Revision and Number of Graphs */
455 if (graph->package.count < 2)
456 return false;
457
458 rev = &graph->package.elements[0];
459 nr_graphs = &graph->package.elements[1];
460
461 if (rev->type != ACPI_TYPE_INTEGER ||
462 nr_graphs->type != ACPI_TYPE_INTEGER)
463 return false;
464
465 /* We only support revision 0 */
466 if (rev->integer.value != 0)
467 return false;
468
469 n = nr_graphs->integer.value;
470 /* CoreSight devices are only part of a single Graph */
471 if (n != 1)
472 return false;
473
474 /* Make sure the ACPI graph package has right number of elements */
475 if (graph->package.count != (n + 2))
476 return false;
477
478 /*
479 * Each entry must be a graph package with at least 3 members :
480 * { GraphID, UUID, NumberOfLinks(n), Links[.],... }
481 */
482 for (i = 2; i < n + 2; i++) {
483 const union acpi_object *obj = &graph->package.elements[i];
484
485 if (obj->type != ACPI_TYPE_PACKAGE ||
486 obj->package.count < 3)
487 return false;
488 }
489
490 return true;
491}
492
493/* acpi_get_dsd_graph - Find the _DSD Graph property for the given device. */
494static const union acpi_object *
495acpi_get_dsd_graph(struct acpi_device *adev, struct acpi_buffer *buf)
496{
497 int i;
498 acpi_status status;
499 const union acpi_object *dsd;
500
501 status = acpi_evaluate_object_typed(object: adev->handle, pathname: "_DSD", NULL,
502 return_buffer: buf, ACPI_TYPE_PACKAGE);
503 if (ACPI_FAILURE(status))
504 return NULL;
505
506 dsd = buf->pointer;
507
508 /*
509 * _DSD property consists tuples { Prop_UUID, Package() }
510 * Iterate through all the packages and find the Graph.
511 */
512 for (i = 0; i + 1 < dsd->package.count; i += 2) {
513 const union acpi_object *guid, *package;
514
515 guid = &dsd->package.elements[i];
516 package = &dsd->package.elements[i + 1];
517
518 /* All _DSD elements must have a UUID and a Package */
519 if (!is_acpi_guid(obj: guid) || package->type != ACPI_TYPE_PACKAGE)
520 break;
521 /* Skip the non-Graph _DSD packages */
522 if (!is_acpi_dsd_graph_guid(obj: guid))
523 continue;
524 if (acpi_validate_dsd_graph(graph: package))
525 return package;
526 /* Invalid graph format, continue */
527 dev_warn(&adev->dev, "Invalid Graph _DSD property\n");
528 }
529
530 return NULL;
531}
532
533static inline bool
534acpi_validate_coresight_graph(const union acpi_object *cs_graph)
535{
536 int nlinks;
537
538 nlinks = cs_graph->package.elements[2].integer.value;
539 /*
540 * Graph must have the following fields :
541 * { GraphID, GraphUUID, NumberOfLinks, Links... }
542 */
543 if (cs_graph->package.count != (nlinks + 3))
544 return false;
545 /* The links are validated in acpi_coresight_parse_link() */
546 return true;
547}
548
549/*
550 * acpi_get_coresight_graph - Parse the device _DSD tables and find
551 * the Graph property matching the CoreSight Graphs.
552 *
553 * Returns the pointer to the CoreSight Graph Package when found. Otherwise
554 * returns NULL.
555 */
556static const union acpi_object *
557acpi_get_coresight_graph(struct acpi_device *adev, struct acpi_buffer *buf)
558{
559 const union acpi_object *graph_list, *graph;
560 int i, nr_graphs;
561
562 graph_list = acpi_get_dsd_graph(adev, buf);
563 if (!graph_list)
564 return graph_list;
565
566 nr_graphs = graph_list->package.elements[1].integer.value;
567
568 for (i = 2; i < nr_graphs + 2; i++) {
569 graph = &graph_list->package.elements[i];
570 if (!is_acpi_coresight_graph(obj: graph))
571 continue;
572 if (acpi_validate_coresight_graph(cs_graph: graph))
573 return graph;
574 /* Invalid graph format */
575 break;
576 }
577
578 return NULL;
579}
580
581/*
582 * acpi_coresight_parse_link - Parse the given Graph connection
583 * of the device and populate the coresight_connection for an output
584 * connection.
585 *
586 * CoreSight Graph specification mandates that the direction of the data
587 * flow must be specified in the link. i.e,
588 *
589 * SourcePortAddress, // Integer
590 * DestinationPortAddress, // Integer
591 * DestinationDeviceName, // Reference to another device
592 * DirectionOfFlow, // 1 for output(master), 0 for input(slave)
593 *
594 * Returns the direction of the data flow [ Input(slave) or Output(master) ]
595 * upon success.
596 * Returns an negative error number otherwise.
597 */
598static int acpi_coresight_parse_link(struct acpi_device *adev,
599 const union acpi_object *link,
600 struct coresight_connection *conn)
601{
602 int dir;
603 const union acpi_object *fields;
604 struct acpi_device *r_adev;
605 struct device *rdev;
606
607 if (link->type != ACPI_TYPE_PACKAGE ||
608 link->package.count != 4)
609 return -EINVAL;
610
611 fields = link->package.elements;
612
613 if (fields[0].type != ACPI_TYPE_INTEGER ||
614 fields[1].type != ACPI_TYPE_INTEGER ||
615 fields[2].type != ACPI_TYPE_LOCAL_REFERENCE ||
616 fields[3].type != ACPI_TYPE_INTEGER)
617 return -EINVAL;
618
619 r_adev = acpi_fetch_acpi_dev(handle: fields[2].reference.handle);
620 if (!r_adev)
621 return -ENODEV;
622
623 dir = fields[3].integer.value;
624 if (dir == ACPI_CORESIGHT_LINK_MASTER) {
625 conn->src_port = fields[0].integer.value;
626 conn->dest_port = fields[1].integer.value;
627 rdev = coresight_find_device_by_fwnode(fwnode: &r_adev->fwnode);
628 if (!rdev)
629 return -EPROBE_DEFER;
630 /*
631 * Hold the refcount to the target device. This could be
632 * released via:
633 * 1) coresight_release_platform_data() if the probe fails or
634 * this device is unregistered.
635 * 2) While removing the target device via
636 * coresight_remove_match().
637 */
638 conn->dest_fwnode = fwnode_handle_get(fwnode: &r_adev->fwnode);
639 } else if (dir == ACPI_CORESIGHT_LINK_SLAVE) {
640 /*
641 * We are only interested in the port number
642 * for the input ports at this component.
643 * Store the port number in child_port.
644 */
645 conn->dest_port = fields[0].integer.value;
646 } else {
647 /* Invalid direction */
648 return -EINVAL;
649 }
650
651 return dir;
652}
653
654/*
655 * acpi_coresight_parse_graph - Parse the _DSD CoreSight graph
656 * connection information and populate the supplied coresight_platform_data
657 * instance.
658 */
659static int acpi_coresight_parse_graph(struct device *dev,
660 struct acpi_device *adev,
661 struct coresight_platform_data *pdata)
662{
663 int ret = 0;
664 int i, nlinks;
665 const union acpi_object *graph;
666 struct coresight_connection conn, zero_conn = {};
667 struct coresight_connection *new_conn;
668 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
669
670 graph = acpi_get_coresight_graph(adev, buf: &buf);
671 /*
672 * There are no graph connections, which is fine for some components.
673 * e.g., ETE
674 */
675 if (!graph)
676 goto free;
677
678 nlinks = graph->package.elements[2].integer.value;
679 if (!nlinks)
680 goto free;
681
682 for (i = 0; i < nlinks; i++) {
683 const union acpi_object *link = &graph->package.elements[3 + i];
684 int dir;
685
686 conn = zero_conn;
687 dir = acpi_coresight_parse_link(adev, link, conn: &conn);
688 if (dir < 0) {
689 ret = dir;
690 goto free;
691 }
692
693 if (dir == ACPI_CORESIGHT_LINK_MASTER) {
694 new_conn = coresight_add_out_conn(dev, pdata, &conn);
695 if (IS_ERR(ptr: new_conn)) {
696 ret = PTR_ERR(ptr: new_conn);
697 goto free;
698 }
699 }
700 }
701
702free:
703 /*
704 * When ACPI fails to alloc a buffer, it will free the buffer
705 * created via ACPI_ALLOCATE_BUFFER and set to NULL.
706 * ACPI_FREE can handle NULL pointers, so free it directly.
707 */
708 ACPI_FREE(buf.pointer);
709 return ret;
710}
711
712/*
713 * acpi_handle_to_logical_cpuid - Map a given acpi_handle to the
714 * logical CPU id of the corresponding CPU device.
715 *
716 * Returns the logical CPU id when found. Otherwise returns >= nr_cpus_id.
717 */
718static int
719acpi_handle_to_logical_cpuid(acpi_handle handle)
720{
721 int i;
722 struct acpi_processor *pr;
723
724 for_each_possible_cpu(i) {
725 pr = per_cpu(processors, i);
726 if (pr && pr->handle == handle)
727 break;
728 }
729
730 return i;
731}
732
733/*
734 * acpi_coresigh_get_cpu - Find the logical CPU id of the CPU associated
735 * with this coresight device. With ACPI bindings, the CoreSight components
736 * are listed as child device of the associated CPU.
737 *
738 * Returns the logical CPU id when found. Otherwise returns 0.
739 */
740static int acpi_coresight_get_cpu(struct device *dev)
741{
742 int cpu;
743 acpi_handle cpu_handle;
744 acpi_status status;
745 struct acpi_device *adev = ACPI_COMPANION(dev);
746
747 if (!adev)
748 return -ENODEV;
749 status = acpi_get_parent(object: adev->handle, out_handle: &cpu_handle);
750 if (ACPI_FAILURE(status))
751 return -ENODEV;
752
753 cpu = acpi_handle_to_logical_cpuid(handle: cpu_handle);
754 if (cpu >= nr_cpu_ids)
755 return -ENODEV;
756 return cpu;
757}
758
759static int
760acpi_get_coresight_platform_data(struct device *dev,
761 struct coresight_platform_data *pdata)
762{
763 struct acpi_device *adev;
764
765 adev = ACPI_COMPANION(dev);
766 if (!adev)
767 return -EINVAL;
768
769 return acpi_coresight_parse_graph(dev, adev, pdata);
770}
771
772#else
773
774static inline int
775acpi_get_coresight_platform_data(struct device *dev,
776 struct coresight_platform_data *pdata)
777{
778 return -ENOENT;
779}
780
781static inline int acpi_coresight_get_cpu(struct device *dev)
782{
783 return -ENODEV;
784}
785#endif
786
787int coresight_get_cpu(struct device *dev)
788{
789 if (is_of_node(fwnode: dev->fwnode))
790 return of_coresight_get_cpu(dev);
791 else if (is_acpi_device_node(fwnode: dev->fwnode))
792 return acpi_coresight_get_cpu(dev);
793 return 0;
794}
795EXPORT_SYMBOL_GPL(coresight_get_cpu);
796
797struct coresight_platform_data *
798coresight_get_platform_data(struct device *dev)
799{
800 int ret = -ENOENT;
801 struct coresight_platform_data *pdata = NULL;
802 struct fwnode_handle *fwnode = dev_fwnode(dev);
803
804 if (IS_ERR_OR_NULL(ptr: fwnode))
805 goto error;
806
807 pdata = devm_kzalloc(dev, size: sizeof(*pdata), GFP_KERNEL);
808 if (!pdata) {
809 ret = -ENOMEM;
810 goto error;
811 }
812
813 if (is_of_node(fwnode))
814 ret = of_get_coresight_platform_data(dev, pdata);
815 else if (is_acpi_device_node(fwnode))
816 ret = acpi_get_coresight_platform_data(dev, pdata);
817
818 if (!ret)
819 return pdata;
820error:
821 if (!IS_ERR_OR_NULL(ptr: pdata))
822 /* Cleanup the connection information */
823 coresight_release_platform_data(NULL, dev, pdata);
824 return ERR_PTR(error: ret);
825}
826EXPORT_SYMBOL_GPL(coresight_get_platform_data);
827

source code of linux/drivers/hwtracing/coresight/coresight-platform.c