xref: /linux/drivers/hwtracing/coresight/coresight-platform.c (revision 13845bdc869f136f92ad3d40ea09b867bb4ce467)
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  */
26 struct coresight_connection *
27 coresight_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(-EINVAL);
45 		}
46 	}
47 
48 	pdata->nr_outconns++;
49 	pdata->out_conns =
50 		devm_krealloc_array(dev, pdata->out_conns, pdata->nr_outconns,
51 				    sizeof(*pdata->out_conns), GFP_KERNEL);
52 	if (!pdata->out_conns)
53 		return ERR_PTR(-ENOMEM);
54 
55 	conn = devm_kmalloc(dev, sizeof(struct coresight_connection),
56 			    GFP_KERNEL);
57 	if (!conn)
58 		return ERR_PTR(-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 }
69 EXPORT_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  */
77 int 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, pdata->in_conns, pdata->nr_inconns,
92 				    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 }
98 EXPORT_SYMBOL_GPL(coresight_add_in_conn);
99 
100 static struct device *
101 coresight_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(&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(&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  */
126 struct coresight_device *
127 coresight_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(&coresight_bustype, r_fwnode);
133 	if (dev) {
134 		csdev = to_coresight_device(dev);
135 		put_device(dev);
136 	}
137 	return csdev;
138 }
139 EXPORT_SYMBOL_GPL(coresight_find_csdev_by_fwnode);
140 
141 #ifdef CONFIG_OF
142 static inline bool of_coresight_legacy_ep_is_input(struct device_node *ep)
143 {
144 	return of_property_read_bool(ep, "slave-mode");
145 }
146 
147 static struct device_node *of_coresight_get_port_parent(struct device_node *ep)
148 {
149 	struct device_node *parent = of_graph_get_port_parent(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(parent, "in-ports") ||
156 	    of_node_name_eq(parent, "out-ports"))
157 		parent = of_get_next_parent(parent);
158 
159 	return parent;
160 }
161 
162 static inline struct device_node *
163 of_coresight_get_output_ports_node(const struct device_node *node)
164 {
165 	return of_get_child_by_name(node, "out-ports");
166 }
167 
168 static 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(dev->of_node, "cpu", 0);
177 	if (!dn)
178 		return -ENODEV;
179 
180 	cpu = of_cpu_node_to_id(dn);
181 	of_node_put(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  */
196 static 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(ep, &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(ep);
218 		if (!rep)
219 			break;
220 		rparent = of_coresight_get_port_parent(rep);
221 		if (!rparent)
222 			break;
223 		if (of_graph_parse_endpoint(rep, &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(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(rdev_fwnode);
244 		conn.dest_port = rendpoint.port;
245 
246 		/*
247 		 * Get the firmware node of the filter source through the
248 		 * reference. This could be used to filter the source in
249 		 * building path.
250 		 */
251 		conn.filter_src_fwnode =
252 			fwnode_find_reference(&ep->fwnode, "filter-source", 0);
253 		if (IS_ERR(conn.filter_src_fwnode)) {
254 			conn.filter_src_fwnode = NULL;
255 		} else {
256 			conn.filter_src_dev =
257 			 coresight_find_csdev_by_fwnode(conn.filter_src_fwnode);
258 			if (conn.filter_src_dev &&
259 			    !coresight_is_device_source(conn.filter_src_dev)) {
260 				dev_warn(dev, "port %d: Filter handle is not a trace source : %s\n",
261 					 conn.src_port, dev_name(&conn.filter_src_dev->dev));
262 				conn.filter_src_dev = NULL;
263 				conn.filter_src_fwnode = NULL;
264 			}
265 		}
266 
267 		new_conn = coresight_add_out_conn(dev, pdata, &conn);
268 		if (IS_ERR_VALUE(new_conn)) {
269 			fwnode_handle_put(conn.dest_fwnode);
270 			return PTR_ERR(new_conn);
271 		}
272 		/* Connection record updated */
273 	} while (0);
274 
275 	of_node_put(rparent);
276 	of_node_put(rep);
277 	put_device(rdev);
278 
279 	return ret;
280 }
281 
282 static int of_get_coresight_platform_data(struct device *dev,
283 					  struct coresight_platform_data *pdata)
284 {
285 	int ret = 0;
286 	struct device_node *ep = NULL;
287 	const struct device_node *parent = NULL;
288 	bool legacy_binding = false;
289 	struct device_node *node = dev->of_node;
290 
291 	parent = of_coresight_get_output_ports_node(node);
292 	/*
293 	 * If the DT uses obsoleted bindings, the ports are listed
294 	 * under the device and we need to filter out the input
295 	 * ports.
296 	 */
297 	if (!parent) {
298 		/*
299 		 * Avoid warnings in for_each_endpoint_of_node()
300 		 * if the device doesn't have any graph connections
301 		 */
302 		if (!of_graph_is_present(node))
303 			return 0;
304 		legacy_binding = true;
305 		parent = node;
306 		dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
307 	}
308 
309 	/* Iterate through each output port to discover topology */
310 	for_each_endpoint_of_node(parent, ep) {
311 		/*
312 		 * Legacy binding mixes input/output ports under the
313 		 * same parent. So, skip the input ports if we are dealing
314 		 * with legacy binding, as they processed with their
315 		 * connected output ports.
316 		 */
317 		if (legacy_binding && of_coresight_legacy_ep_is_input(ep))
318 			continue;
319 
320 		ret = of_coresight_parse_endpoint(dev, ep, pdata);
321 		if (ret) {
322 			of_node_put(ep);
323 			return ret;
324 		}
325 	}
326 
327 	return 0;
328 }
329 #else
330 static inline int
331 of_get_coresight_platform_data(struct device *dev,
332 			       struct coresight_platform_data *pdata)
333 {
334 	return -ENOENT;
335 }
336 
337 static inline int of_coresight_get_cpu(struct device *dev)
338 {
339 	return -ENODEV;
340 }
341 #endif
342 
343 #ifdef CONFIG_ACPI
344 
345 #include <acpi/actypes.h>
346 #include <acpi/processor.h>
347 
348 /* ACPI Graph _DSD UUID : "ab02a46b-74c7-45a2-bd68-f7d344ef2153" */
349 static const guid_t acpi_graph_uuid = GUID_INIT(0xab02a46b, 0x74c7, 0x45a2,
350 						0xbd, 0x68, 0xf7, 0xd3,
351 						0x44, 0xef, 0x21, 0x53);
352 /* Coresight ACPI Graph UUID : "3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd" */
353 static const guid_t coresight_graph_uuid = GUID_INIT(0x3ecbc8b6, 0x1d0e, 0x4fb3,
354 						     0x81, 0x07, 0xe6, 0x27,
355 						     0xf8, 0x05, 0xc6, 0xcd);
356 #define ACPI_CORESIGHT_LINK_SLAVE	0
357 #define ACPI_CORESIGHT_LINK_MASTER	1
358 
359 static inline bool is_acpi_guid(const union acpi_object *obj)
360 {
361 	return (obj->type == ACPI_TYPE_BUFFER) && (obj->buffer.length == 16);
362 }
363 
364 /*
365  * acpi_guid_matches	- Checks if the given object is a GUID object and
366  * that it matches the supplied the GUID.
367  */
368 static inline bool acpi_guid_matches(const union acpi_object *obj,
369 				   const guid_t *guid)
370 {
371 	return is_acpi_guid(obj) &&
372 	       guid_equal((guid_t *)obj->buffer.pointer, guid);
373 }
374 
375 static inline bool is_acpi_dsd_graph_guid(const union acpi_object *obj)
376 {
377 	return acpi_guid_matches(obj, &acpi_graph_uuid);
378 }
379 
380 static inline bool is_acpi_coresight_graph_guid(const union acpi_object *obj)
381 {
382 	return acpi_guid_matches(obj, &coresight_graph_uuid);
383 }
384 
385 static inline bool is_acpi_coresight_graph(const union acpi_object *obj)
386 {
387 	const union acpi_object *graphid, *guid, *links;
388 
389 	if (obj->type != ACPI_TYPE_PACKAGE ||
390 	    obj->package.count < 3)
391 		return false;
392 
393 	graphid = &obj->package.elements[0];
394 	guid = &obj->package.elements[1];
395 	links = &obj->package.elements[2];
396 
397 	if (graphid->type != ACPI_TYPE_INTEGER ||
398 	    links->type != ACPI_TYPE_INTEGER)
399 		return false;
400 
401 	return is_acpi_coresight_graph_guid(guid);
402 }
403 
404 /*
405  * acpi_validate_dsd_graph	- Make sure the given _DSD graph conforms
406  * to the ACPI _DSD Graph specification.
407  *
408  * ACPI Devices Graph property has the following format:
409  *  {
410  *	Revision	- Integer, must be 0
411  *	NumberOfGraphs	- Integer, N indicating the following list.
412  *	Graph[1],
413  *	 ...
414  *	Graph[N]
415  *  }
416  *
417  * And each Graph entry has the following format:
418  *  {
419  *	GraphID		- Integer, identifying a graph the device belongs to.
420  *	UUID		- UUID identifying the specification that governs
421  *			  this graph. (e.g, see is_acpi_coresight_graph())
422  *	NumberOfLinks	- Number "N" of connections on this node of the graph.
423  *	Links[1]
424  *	...
425  *	Links[N]
426  *  }
427  *
428  * Where each "Links" entry has the following format:
429  *
430  * {
431  *	SourcePortAddress	- Integer
432  *	DestinationPortAddress	- Integer
433  *	DestinationDeviceName	- Reference to another device
434  *	( --- CoreSight specific extensions below ---)
435  *	DirectionOfFlow		- Integer 1 for output(master)
436  *				  0 for input(slave)
437  * }
438  *
439  * e.g:
440  * For a Funnel device
441  *
442  * Device(MFUN) {
443  *   ...
444  *
445  *   Name (_DSD, Package() {
446  *	// DSD Package contains tuples of {  Proeprty_Type_UUID, Package() }
447  *	ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), //Std. Property UUID
448  *	Package() {
449  *		Package(2) { "property-name", <property-value> }
450  *	},
451  *
452  *	ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), // ACPI Graph UUID
453  *	Package() {
454  *	  0,		// Revision
455  *	  1,		// NumberOfGraphs.
456  *	  Package() {	// Graph[0] Package
457  *	     1,		// GraphID
458  *	     // Coresight Graph UUID
459  *	     ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"),
460  *	     3,		// NumberOfLinks aka ports
461  *	     // Link[0]: Output_0 -> Replicator:Input_0
462  *	     Package () { 0, 0, \_SB_.RPL0, 1 },
463  *	     // Link[1]: Input_0 <- Cluster0_Funnel0:Output_0
464  *	     Package () { 0, 0, \_SB_.CLU0.FUN0, 0 },
465  *	     // Link[2]: Input_1 <- Cluster1_Funnel0:Output_0
466  *	      Package () { 1, 0, \_SB_.CLU1.FUN0, 0 },
467  *	  }	// End of Graph[0] Package
468  *
469  *	}, // End of ACPI Graph Property
470  *  })
471  */
472 static inline bool acpi_validate_dsd_graph(const union acpi_object *graph)
473 {
474 	int i, n;
475 	const union acpi_object *rev, *nr_graphs;
476 
477 	/* The graph must contain at least the Revision and Number of Graphs */
478 	if (graph->package.count < 2)
479 		return false;
480 
481 	rev = &graph->package.elements[0];
482 	nr_graphs = &graph->package.elements[1];
483 
484 	if (rev->type != ACPI_TYPE_INTEGER ||
485 	    nr_graphs->type != ACPI_TYPE_INTEGER)
486 		return false;
487 
488 	/* We only support revision 0 */
489 	if (rev->integer.value != 0)
490 		return false;
491 
492 	n = nr_graphs->integer.value;
493 	/* CoreSight devices are only part of a single Graph */
494 	if (n != 1)
495 		return false;
496 
497 	/* Make sure the ACPI graph package has right number of elements */
498 	if (graph->package.count != (n + 2))
499 		return false;
500 
501 	/*
502 	 * Each entry must be a graph package with at least 3 members :
503 	 * { GraphID, UUID, NumberOfLinks(n), Links[.],... }
504 	 */
505 	for (i = 2; i < n + 2; i++) {
506 		const union acpi_object *obj = &graph->package.elements[i];
507 
508 		if (obj->type != ACPI_TYPE_PACKAGE ||
509 		    obj->package.count < 3)
510 			return false;
511 	}
512 
513 	return true;
514 }
515 
516 /* acpi_get_dsd_graph	- Find the _DSD Graph property for the given device. */
517 static const union acpi_object *
518 acpi_get_dsd_graph(struct acpi_device *adev, struct acpi_buffer *buf)
519 {
520 	int i;
521 	acpi_status status;
522 	const union acpi_object *dsd;
523 
524 	status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL,
525 					    buf, ACPI_TYPE_PACKAGE);
526 	if (ACPI_FAILURE(status))
527 		return NULL;
528 
529 	dsd = buf->pointer;
530 
531 	/*
532 	 * _DSD property consists tuples { Prop_UUID, Package() }
533 	 * Iterate through all the packages and find the Graph.
534 	 */
535 	for (i = 0; i + 1 < dsd->package.count; i += 2) {
536 		const union acpi_object *guid, *package;
537 
538 		guid = &dsd->package.elements[i];
539 		package = &dsd->package.elements[i + 1];
540 
541 		/* All _DSD elements must have a UUID and a Package */
542 		if (!is_acpi_guid(guid) || package->type != ACPI_TYPE_PACKAGE)
543 			break;
544 		/* Skip the non-Graph _DSD packages */
545 		if (!is_acpi_dsd_graph_guid(guid))
546 			continue;
547 		if (acpi_validate_dsd_graph(package))
548 			return package;
549 		/* Invalid graph format, continue */
550 		dev_warn(&adev->dev, "Invalid Graph _DSD property\n");
551 	}
552 
553 	return NULL;
554 }
555 
556 static inline bool
557 acpi_validate_coresight_graph(const union acpi_object *cs_graph)
558 {
559 	int nlinks;
560 
561 	nlinks = cs_graph->package.elements[2].integer.value;
562 	/*
563 	 * Graph must have the following fields :
564 	 * { GraphID, GraphUUID, NumberOfLinks, Links... }
565 	 */
566 	if (cs_graph->package.count != (nlinks + 3))
567 		return false;
568 	/* The links are validated in acpi_coresight_parse_link() */
569 	return true;
570 }
571 
572 /*
573  * acpi_get_coresight_graph	- Parse the device _DSD tables and find
574  * the Graph property matching the CoreSight Graphs.
575  *
576  * Returns the pointer to the CoreSight Graph Package when found. Otherwise
577  * returns NULL.
578  */
579 static const union acpi_object *
580 acpi_get_coresight_graph(struct acpi_device *adev, struct acpi_buffer *buf)
581 {
582 	const union acpi_object *graph_list, *graph;
583 	int i, nr_graphs;
584 
585 	graph_list = acpi_get_dsd_graph(adev, buf);
586 	if (!graph_list)
587 		return graph_list;
588 
589 	nr_graphs = graph_list->package.elements[1].integer.value;
590 
591 	for (i = 2; i < nr_graphs + 2; i++) {
592 		graph = &graph_list->package.elements[i];
593 		if (!is_acpi_coresight_graph(graph))
594 			continue;
595 		if (acpi_validate_coresight_graph(graph))
596 			return graph;
597 		/* Invalid graph format */
598 		break;
599 	}
600 
601 	return NULL;
602 }
603 
604 /*
605  * acpi_coresight_parse_link	- Parse the given Graph connection
606  * of the device and populate the coresight_connection for an output
607  * connection.
608  *
609  * CoreSight Graph specification mandates that the direction of the data
610  * flow must be specified in the link. i.e,
611  *
612  *	SourcePortAddress,	// Integer
613  *	DestinationPortAddress,	// Integer
614  *	DestinationDeviceName,	// Reference to another device
615  *	DirectionOfFlow,	// 1 for output(master), 0 for input(slave)
616  *
617  * Returns the direction of the data flow [ Input(slave) or Output(master) ]
618  * upon success.
619  * Returns an negative error number otherwise.
620  */
621 static int acpi_coresight_parse_link(struct acpi_device *adev,
622 				     const union acpi_object *link,
623 				     struct coresight_connection *conn)
624 {
625 	int dir;
626 	const union acpi_object *fields;
627 	struct acpi_device *r_adev;
628 	struct device *rdev;
629 
630 	if (link->type != ACPI_TYPE_PACKAGE ||
631 	    link->package.count != 4)
632 		return -EINVAL;
633 
634 	fields = link->package.elements;
635 
636 	if (fields[0].type != ACPI_TYPE_INTEGER ||
637 	    fields[1].type != ACPI_TYPE_INTEGER ||
638 	    fields[2].type != ACPI_TYPE_LOCAL_REFERENCE ||
639 	    fields[3].type != ACPI_TYPE_INTEGER)
640 		return -EINVAL;
641 
642 	r_adev = acpi_fetch_acpi_dev(fields[2].reference.handle);
643 	if (!r_adev)
644 		return -ENODEV;
645 
646 	dir = fields[3].integer.value;
647 	if (dir == ACPI_CORESIGHT_LINK_MASTER) {
648 		conn->src_port = fields[0].integer.value;
649 		conn->dest_port = fields[1].integer.value;
650 		rdev = coresight_find_device_by_fwnode(&r_adev->fwnode);
651 		if (!rdev)
652 			return -EPROBE_DEFER;
653 		/*
654 		 * Hold the refcount to the target device. This could be
655 		 * released via:
656 		 * 1) coresight_release_platform_data() if the probe fails or
657 		 *    this device is unregistered.
658 		 * 2) While removing the target device via
659 		 *    coresight_remove_match().
660 		 */
661 		conn->dest_fwnode = fwnode_handle_get(&r_adev->fwnode);
662 	} else if (dir == ACPI_CORESIGHT_LINK_SLAVE) {
663 		/*
664 		 * We are only interested in the port number
665 		 * for the input ports at this component.
666 		 * Store the port number in child_port.
667 		 */
668 		conn->dest_port = fields[0].integer.value;
669 	} else {
670 		/* Invalid direction */
671 		return -EINVAL;
672 	}
673 
674 	return dir;
675 }
676 
677 /*
678  * acpi_coresight_parse_graph	- Parse the _DSD CoreSight graph
679  * connection information and populate the supplied coresight_platform_data
680  * instance.
681  */
682 static int acpi_coresight_parse_graph(struct device *dev,
683 				      struct acpi_device *adev,
684 				      struct coresight_platform_data *pdata)
685 {
686 	int ret = 0;
687 	int i, nlinks;
688 	const union acpi_object *graph;
689 	struct coresight_connection conn, zero_conn = {};
690 	struct coresight_connection *new_conn;
691 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
692 
693 	graph = acpi_get_coresight_graph(adev, &buf);
694 	/*
695 	 * There are no graph connections, which is fine for some components.
696 	 * e.g., ETE
697 	 */
698 	if (!graph)
699 		goto free;
700 
701 	nlinks = graph->package.elements[2].integer.value;
702 	if (!nlinks)
703 		goto free;
704 
705 	for (i = 0; i < nlinks; i++) {
706 		const union acpi_object *link = &graph->package.elements[3 + i];
707 		int dir;
708 
709 		conn = zero_conn;
710 		dir = acpi_coresight_parse_link(adev, link, &conn);
711 		if (dir < 0) {
712 			ret = dir;
713 			goto free;
714 		}
715 
716 		if (dir == ACPI_CORESIGHT_LINK_MASTER) {
717 			new_conn = coresight_add_out_conn(dev, pdata, &conn);
718 			if (IS_ERR(new_conn)) {
719 				ret = PTR_ERR(new_conn);
720 				goto free;
721 			}
722 		}
723 	}
724 
725 free:
726 	/*
727 	 * When ACPI fails to alloc a buffer, it will free the buffer
728 	 * created via ACPI_ALLOCATE_BUFFER and set to NULL.
729 	 * ACPI_FREE can handle NULL pointers, so free it directly.
730 	 */
731 	ACPI_FREE(buf.pointer);
732 	return ret;
733 }
734 
735 /*
736  * acpi_handle_to_logical_cpuid - Map a given acpi_handle to the
737  * logical CPU id of the corresponding CPU device.
738  *
739  * Returns the logical CPU id when found. Otherwise returns >= nr_cpus_id.
740  */
741 static int
742 acpi_handle_to_logical_cpuid(acpi_handle handle)
743 {
744 	int i;
745 	struct acpi_processor *pr;
746 
747 	for_each_possible_cpu(i) {
748 		pr = per_cpu(processors, i);
749 		if (pr && pr->handle == handle)
750 			break;
751 	}
752 
753 	return i;
754 }
755 
756 /*
757  * acpi_coresigh_get_cpu - Find the logical CPU id of the CPU associated
758  * with this coresight device. With ACPI bindings, the CoreSight components
759  * are listed as child device of the associated CPU.
760  *
761  * Returns the logical CPU id when found. Otherwise returns 0.
762  */
763 static int acpi_coresight_get_cpu(struct device *dev)
764 {
765 	int cpu;
766 	acpi_handle cpu_handle;
767 	acpi_status status;
768 	struct acpi_device *adev = ACPI_COMPANION(dev);
769 
770 	if (!adev)
771 		return -ENODEV;
772 	status = acpi_get_parent(adev->handle, &cpu_handle);
773 	if (ACPI_FAILURE(status))
774 		return -ENODEV;
775 
776 	cpu = acpi_handle_to_logical_cpuid(cpu_handle);
777 	if (cpu >= nr_cpu_ids)
778 		return -ENODEV;
779 	return cpu;
780 }
781 
782 static int
783 acpi_get_coresight_platform_data(struct device *dev,
784 				 struct coresight_platform_data *pdata)
785 {
786 	struct acpi_device *adev;
787 
788 	adev = ACPI_COMPANION(dev);
789 	if (!adev)
790 		return -EINVAL;
791 
792 	return acpi_coresight_parse_graph(dev, adev, pdata);
793 }
794 
795 #else
796 
797 static inline int
798 acpi_get_coresight_platform_data(struct device *dev,
799 				 struct coresight_platform_data *pdata)
800 {
801 	return -ENOENT;
802 }
803 
804 static inline int acpi_coresight_get_cpu(struct device *dev)
805 {
806 	return -ENODEV;
807 }
808 #endif
809 
810 int coresight_get_cpu(struct device *dev)
811 {
812 	if (is_of_node(dev->fwnode))
813 		return of_coresight_get_cpu(dev);
814 	else if (is_acpi_device_node(dev->fwnode))
815 		return acpi_coresight_get_cpu(dev);
816 	return 0;
817 }
818 EXPORT_SYMBOL_GPL(coresight_get_cpu);
819 
820 int coresight_get_static_trace_id(struct device *dev, u32 *id)
821 {
822 	return fwnode_property_read_u32(dev_fwnode(dev), "arm,static-trace-id", id);
823 }
824 EXPORT_SYMBOL_GPL(coresight_get_static_trace_id);
825 
826 struct coresight_platform_data *
827 coresight_get_platform_data(struct device *dev)
828 {
829 	int ret = -ENOENT;
830 	struct coresight_platform_data *pdata = NULL;
831 	struct fwnode_handle *fwnode = dev_fwnode(dev);
832 
833 	if (IS_ERR_OR_NULL(fwnode))
834 		goto error;
835 
836 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
837 	if (!pdata) {
838 		ret = -ENOMEM;
839 		goto error;
840 	}
841 
842 	if (is_of_node(fwnode))
843 		ret = of_get_coresight_platform_data(dev, pdata);
844 	else if (is_acpi_device_node(fwnode))
845 		ret = acpi_get_coresight_platform_data(dev, pdata);
846 
847 	if (!ret)
848 		return pdata;
849 error:
850 	if (!IS_ERR_OR_NULL(pdata))
851 		/* Cleanup the connection information */
852 		coresight_release_platform_data(NULL, dev, pdata);
853 	return ERR_PTR(ret);
854 }
855 EXPORT_SYMBOL_GPL(coresight_get_platform_data);
856