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 		new_conn = coresight_add_out_conn(dev, pdata, &conn);
247 		if (IS_ERR_VALUE(new_conn)) {
248 			fwnode_handle_put(conn.dest_fwnode);
249 			return PTR_ERR(new_conn);
250 		}
251 		/* Connection record updated */
252 	} while (0);
253 
254 	of_node_put(rparent);
255 	of_node_put(rep);
256 	put_device(rdev);
257 
258 	return ret;
259 }
260 
261 static 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, 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
307 static inline int
308 of_get_coresight_platform_data(struct device *dev,
309 			       struct coresight_platform_data *pdata)
310 {
311 	return -ENOENT;
312 }
313 
314 static 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" */
326 static 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" */
330 static 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 
336 static 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  */
345 static 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((guid_t *)obj->buffer.pointer, guid);
350 }
351 
352 static inline bool is_acpi_dsd_graph_guid(const union acpi_object *obj)
353 {
354 	return acpi_guid_matches(obj, &acpi_graph_uuid);
355 }
356 
357 static inline bool is_acpi_coresight_graph_guid(const union acpi_object *obj)
358 {
359 	return acpi_guid_matches(obj, &coresight_graph_uuid);
360 }
361 
362 static 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(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  */
449 static 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. */
494 static const union acpi_object *
495 acpi_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(adev->handle, "_DSD", NULL,
502 					    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(guid) || package->type != ACPI_TYPE_PACKAGE)
520 			break;
521 		/* Skip the non-Graph _DSD packages */
522 		if (!is_acpi_dsd_graph_guid(guid))
523 			continue;
524 		if (acpi_validate_dsd_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 
533 static inline bool
534 acpi_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  */
556 static const union acpi_object *
557 acpi_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(graph))
571 			continue;
572 		if (acpi_validate_coresight_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  */
598 static 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(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(&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(&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  */
659 static 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);
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);
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(new_conn)) {
696 				ret = PTR_ERR(new_conn);
697 				goto free;
698 			}
699 		}
700 	}
701 
702 free:
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  */
718 static int
719 acpi_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  */
740 static 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(adev->handle, &cpu_handle);
750 	if (ACPI_FAILURE(status))
751 		return -ENODEV;
752 
753 	cpu = acpi_handle_to_logical_cpuid(cpu_handle);
754 	if (cpu >= nr_cpu_ids)
755 		return -ENODEV;
756 	return cpu;
757 }
758 
759 static int
760 acpi_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 
774 static inline int
775 acpi_get_coresight_platform_data(struct device *dev,
776 				 struct coresight_platform_data *pdata)
777 {
778 	return -ENOENT;
779 }
780 
781 static inline int acpi_coresight_get_cpu(struct device *dev)
782 {
783 	return -ENODEV;
784 }
785 #endif
786 
787 int coresight_get_cpu(struct device *dev)
788 {
789 	if (is_of_node(dev->fwnode))
790 		return of_coresight_get_cpu(dev);
791 	else if (is_acpi_device_node(dev->fwnode))
792 		return acpi_coresight_get_cpu(dev);
793 	return 0;
794 }
795 EXPORT_SYMBOL_GPL(coresight_get_cpu);
796 
797 struct coresight_platform_data *
798 coresight_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(fwnode))
805 		goto error;
806 
807 	pdata = devm_kzalloc(dev, 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;
820 error:
821 	if (!IS_ERR_OR_NULL(pdata))
822 		/* Cleanup the connection information */
823 		coresight_release_platform_data(NULL, dev, pdata);
824 	return ERR_PTR(ret);
825 }
826 EXPORT_SYMBOL_GPL(coresight_get_platform_data);
827