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_address.h>
13 #include <linux/of_graph.h>
14 #include <linux/of_platform.h>
15 #include <linux/platform_device.h>
16 #include <linux/amba/bus.h>
17 #include <linux/coresight.h>
18 #include <linux/cpumask.h>
19 #include <asm/smp_plat.h>
20 
21 #include "coresight-priv.h"
22 /*
23  * coresight_alloc_conns: Allocate connections record for each output
24  * port from the device.
25  */
26 static int coresight_alloc_conns(struct device *dev,
27 				 struct coresight_platform_data *pdata)
28 {
29 	if (pdata->nr_outport) {
30 		pdata->conns = devm_kcalloc(dev, pdata->nr_outport,
31 					    sizeof(*pdata->conns), GFP_KERNEL);
32 		if (!pdata->conns)
33 			return -ENOMEM;
34 	}
35 
36 	return 0;
37 }
38 
39 static struct device *
40 coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
41 {
42 	struct device *dev = NULL;
43 
44 	/*
45 	 * If we have a non-configurable replicator, it will be found on the
46 	 * platform bus.
47 	 */
48 	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
49 	if (dev)
50 		return dev;
51 
52 	/*
53 	 * We have a configurable component - circle through the AMBA bus
54 	 * looking for the device that matches the endpoint node.
55 	 */
56 	return bus_find_device_by_fwnode(&amba_bustype, fwnode);
57 }
58 
59 /*
60  * Find a registered coresight device from a device fwnode.
61  * The node info is associated with the AMBA parent, but the
62  * csdev keeps a copy so iterate round the coresight bus to
63  * find the device.
64  */
65 struct coresight_device *
66 coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode)
67 {
68 	struct device *dev;
69 	struct coresight_device *csdev = NULL;
70 
71 	dev = bus_find_device_by_fwnode(&coresight_bustype, r_fwnode);
72 	if (dev) {
73 		csdev = to_coresight_device(dev);
74 		put_device(dev);
75 	}
76 	return csdev;
77 }
78 EXPORT_SYMBOL_GPL(coresight_find_csdev_by_fwnode);
79 
80 #ifdef CONFIG_OF
81 static inline bool of_coresight_legacy_ep_is_input(struct device_node *ep)
82 {
83 	return of_property_read_bool(ep, "slave-mode");
84 }
85 
86 static void of_coresight_get_ports_legacy(const struct device_node *node,
87 					  int *nr_inport, int *nr_outport)
88 {
89 	struct device_node *ep = NULL;
90 	struct of_endpoint endpoint;
91 	int in = 0, out = 0;
92 
93 	/*
94 	 * Avoid warnings in of_graph_get_next_endpoint()
95 	 * if the device doesn't have any graph connections
96 	 */
97 	if (!of_graph_is_present(node))
98 		return;
99 	do {
100 		ep = of_graph_get_next_endpoint(node, ep);
101 		if (!ep)
102 			break;
103 
104 		if (of_graph_parse_endpoint(ep, &endpoint))
105 			continue;
106 
107 		if (of_coresight_legacy_ep_is_input(ep)) {
108 			in = (endpoint.port + 1 > in) ?
109 				endpoint.port + 1 : in;
110 		} else {
111 			out = (endpoint.port + 1) > out ?
112 				endpoint.port + 1 : out;
113 		}
114 
115 	} while (ep);
116 
117 	*nr_inport = in;
118 	*nr_outport = out;
119 }
120 
121 static struct device_node *of_coresight_get_port_parent(struct device_node *ep)
122 {
123 	struct device_node *parent = of_graph_get_port_parent(ep);
124 
125 	/*
126 	 * Skip one-level up to the real device node, if we
127 	 * are using the new bindings.
128 	 */
129 	if (of_node_name_eq(parent, "in-ports") ||
130 	    of_node_name_eq(parent, "out-ports"))
131 		parent = of_get_next_parent(parent);
132 
133 	return parent;
134 }
135 
136 static inline struct device_node *
137 of_coresight_get_input_ports_node(const struct device_node *node)
138 {
139 	return of_get_child_by_name(node, "in-ports");
140 }
141 
142 static inline struct device_node *
143 of_coresight_get_output_ports_node(const struct device_node *node)
144 {
145 	return of_get_child_by_name(node, "out-ports");
146 }
147 
148 static inline int
149 of_coresight_count_ports(struct device_node *port_parent)
150 {
151 	int i = 0;
152 	struct device_node *ep = NULL;
153 	struct of_endpoint endpoint;
154 
155 	while ((ep = of_graph_get_next_endpoint(port_parent, ep))) {
156 		/* Defer error handling to parsing */
157 		if (of_graph_parse_endpoint(ep, &endpoint))
158 			continue;
159 		if (endpoint.port + 1 > i)
160 			i = endpoint.port + 1;
161 	}
162 
163 	return i;
164 }
165 
166 static void of_coresight_get_ports(const struct device_node *node,
167 				   int *nr_inport, int *nr_outport)
168 {
169 	struct device_node *input_ports = NULL, *output_ports = NULL;
170 
171 	input_ports = of_coresight_get_input_ports_node(node);
172 	output_ports = of_coresight_get_output_ports_node(node);
173 
174 	if (input_ports || output_ports) {
175 		if (input_ports) {
176 			*nr_inport = of_coresight_count_ports(input_ports);
177 			of_node_put(input_ports);
178 		}
179 		if (output_ports) {
180 			*nr_outport = of_coresight_count_ports(output_ports);
181 			of_node_put(output_ports);
182 		}
183 	} else {
184 		/* Fall back to legacy DT bindings parsing */
185 		of_coresight_get_ports_legacy(node, nr_inport, nr_outport);
186 	}
187 }
188 
189 static int of_coresight_get_cpu(struct device *dev)
190 {
191 	int cpu;
192 	struct device_node *dn;
193 
194 	if (!dev->of_node)
195 		return -ENODEV;
196 
197 	dn = of_parse_phandle(dev->of_node, "cpu", 0);
198 	if (!dn)
199 		return -ENODEV;
200 
201 	cpu = of_cpu_node_to_id(dn);
202 	of_node_put(dn);
203 
204 	return cpu;
205 }
206 
207 /*
208  * of_coresight_parse_endpoint : Parse the given output endpoint @ep
209  * and fill the connection information in @conn
210  *
211  * Parses the local port, remote device name and the remote port.
212  *
213  * Returns :
214  *	 0	- If the parsing completed without any fatal errors.
215  *	-Errno	- Fatal error, abort the scanning.
216  */
217 static int of_coresight_parse_endpoint(struct device *dev,
218 				       struct device_node *ep,
219 				       struct coresight_platform_data *pdata)
220 {
221 	int ret = 0;
222 	struct of_endpoint endpoint, rendpoint;
223 	struct device_node *rparent = NULL;
224 	struct device_node *rep = NULL;
225 	struct device *rdev = NULL;
226 	struct fwnode_handle *rdev_fwnode;
227 	struct coresight_connection *conn;
228 
229 	do {
230 		/* Parse the local port details */
231 		if (of_graph_parse_endpoint(ep, &endpoint))
232 			break;
233 		/*
234 		 * Get a handle on the remote endpoint and the device it is
235 		 * attached to.
236 		 */
237 		rep = of_graph_get_remote_endpoint(ep);
238 		if (!rep)
239 			break;
240 		rparent = of_coresight_get_port_parent(rep);
241 		if (!rparent)
242 			break;
243 		if (of_graph_parse_endpoint(rep, &rendpoint))
244 			break;
245 
246 		rdev_fwnode = of_fwnode_handle(rparent);
247 		/* If the remote device is not available, defer probing */
248 		rdev = coresight_find_device_by_fwnode(rdev_fwnode);
249 		if (!rdev) {
250 			ret = -EPROBE_DEFER;
251 			break;
252 		}
253 
254 		conn = &pdata->conns[endpoint.port];
255 		if (conn->child_fwnode) {
256 			dev_warn(dev, "Duplicate output port %d\n",
257 				 endpoint.port);
258 			ret = -EINVAL;
259 			break;
260 		}
261 		conn->outport = endpoint.port;
262 		/*
263 		 * Hold the refcount to the target device. This could be
264 		 * released via:
265 		 * 1) coresight_release_platform_data() if the probe fails or
266 		 *    this device is unregistered.
267 		 * 2) While removing the target device via
268 		 *    coresight_remove_match()
269 		 */
270 		conn->child_fwnode = fwnode_handle_get(rdev_fwnode);
271 		conn->child_port = rendpoint.port;
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 	/* Get the number of input and output port for this component */
292 	of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport);
293 
294 	/* If there are no output connections, we are done */
295 	if (!pdata->nr_outport)
296 		return 0;
297 
298 	ret = coresight_alloc_conns(dev, pdata);
299 	if (ret)
300 		return ret;
301 
302 	parent = of_coresight_get_output_ports_node(node);
303 	/*
304 	 * If the DT uses obsoleted bindings, the ports are listed
305 	 * under the device and we need to filter out the input
306 	 * ports.
307 	 */
308 	if (!parent) {
309 		legacy_binding = true;
310 		parent = node;
311 		dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
312 	}
313 
314 	/* Iterate through each output port to discover topology */
315 	while ((ep = of_graph_get_next_endpoint(parent, ep))) {
316 		/*
317 		 * Legacy binding mixes input/output ports under the
318 		 * same parent. So, skip the input ports if we are dealing
319 		 * with legacy binding, as they processed with their
320 		 * connected output ports.
321 		 */
322 		if (legacy_binding && of_coresight_legacy_ep_is_input(ep))
323 			continue;
324 
325 		ret = of_coresight_parse_endpoint(dev, ep, pdata);
326 		if (ret)
327 			return ret;
328 	}
329 
330 	return 0;
331 }
332 #else
333 static inline int
334 of_get_coresight_platform_data(struct device *dev,
335 			       struct coresight_platform_data *pdata)
336 {
337 	return -ENOENT;
338 }
339 
340 static inline int of_coresight_get_cpu(struct device *dev)
341 {
342 	return -ENODEV;
343 }
344 #endif
345 
346 #ifdef CONFIG_ACPI
347 
348 #include <acpi/actypes.h>
349 #include <acpi/processor.h>
350 
351 /* ACPI Graph _DSD UUID : "ab02a46b-74c7-45a2-bd68-f7d344ef2153" */
352 static const guid_t acpi_graph_uuid = GUID_INIT(0xab02a46b, 0x74c7, 0x45a2,
353 						0xbd, 0x68, 0xf7, 0xd3,
354 						0x44, 0xef, 0x21, 0x53);
355 /* Coresight ACPI Graph UUID : "3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd" */
356 static const guid_t coresight_graph_uuid = GUID_INIT(0x3ecbc8b6, 0x1d0e, 0x4fb3,
357 						     0x81, 0x07, 0xe6, 0x27,
358 						     0xf8, 0x05, 0xc6, 0xcd);
359 #define ACPI_CORESIGHT_LINK_SLAVE	0
360 #define ACPI_CORESIGHT_LINK_MASTER	1
361 
362 static inline bool is_acpi_guid(const union acpi_object *obj)
363 {
364 	return (obj->type == ACPI_TYPE_BUFFER) && (obj->buffer.length == 16);
365 }
366 
367 /*
368  * acpi_guid_matches	- Checks if the given object is a GUID object and
369  * that it matches the supplied the GUID.
370  */
371 static inline bool acpi_guid_matches(const union acpi_object *obj,
372 				   const guid_t *guid)
373 {
374 	return is_acpi_guid(obj) &&
375 	       guid_equal((guid_t *)obj->buffer.pointer, guid);
376 }
377 
378 static inline bool is_acpi_dsd_graph_guid(const union acpi_object *obj)
379 {
380 	return acpi_guid_matches(obj, &acpi_graph_uuid);
381 }
382 
383 static inline bool is_acpi_coresight_graph_guid(const union acpi_object *obj)
384 {
385 	return acpi_guid_matches(obj, &coresight_graph_uuid);
386 }
387 
388 static inline bool is_acpi_coresight_graph(const union acpi_object *obj)
389 {
390 	const union acpi_object *graphid, *guid, *links;
391 
392 	if (obj->type != ACPI_TYPE_PACKAGE ||
393 	    obj->package.count < 3)
394 		return false;
395 
396 	graphid = &obj->package.elements[0];
397 	guid = &obj->package.elements[1];
398 	links = &obj->package.elements[2];
399 
400 	if (graphid->type != ACPI_TYPE_INTEGER ||
401 	    links->type != ACPI_TYPE_INTEGER)
402 		return false;
403 
404 	return is_acpi_coresight_graph_guid(guid);
405 }
406 
407 /*
408  * acpi_validate_dsd_graph	- Make sure the given _DSD graph conforms
409  * to the ACPI _DSD Graph specification.
410  *
411  * ACPI Devices Graph property has the following format:
412  *  {
413  *	Revision	- Integer, must be 0
414  *	NumberOfGraphs	- Integer, N indicating the following list.
415  *	Graph[1],
416  *	 ...
417  *	Graph[N]
418  *  }
419  *
420  * And each Graph entry has the following format:
421  *  {
422  *	GraphID		- Integer, identifying a graph the device belongs to.
423  *	UUID		- UUID identifying the specification that governs
424  *			  this graph. (e.g, see is_acpi_coresight_graph())
425  *	NumberOfLinks	- Number "N" of connections on this node of the graph.
426  *	Links[1]
427  *	...
428  *	Links[N]
429  *  }
430  *
431  * Where each "Links" entry has the following format:
432  *
433  * {
434  *	SourcePortAddress	- Integer
435  *	DestinationPortAddress	- Integer
436  *	DestinationDeviceName	- Reference to another device
437  *	( --- CoreSight specific extensions below ---)
438  *	DirectionOfFlow		- Integer 1 for output(master)
439  *				  0 for input(slave)
440  * }
441  *
442  * e.g:
443  * For a Funnel device
444  *
445  * Device(MFUN) {
446  *   ...
447  *
448  *   Name (_DSD, Package() {
449  *	// DSD Package contains tuples of {  Proeprty_Type_UUID, Package() }
450  *	ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), //Std. Property UUID
451  *	Package() {
452  *		Package(2) { "property-name", <property-value> }
453  *	},
454  *
455  *	ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), // ACPI Graph UUID
456  *	Package() {
457  *	  0,		// Revision
458  *	  1,		// NumberOfGraphs.
459  *	  Package() {	// Graph[0] Package
460  *	     1,		// GraphID
461  *	     // Coresight Graph UUID
462  *	     ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"),
463  *	     3,		// NumberOfLinks aka ports
464  *	     // Link[0]: Output_0 -> Replicator:Input_0
465  *	     Package () { 0, 0, \_SB_.RPL0, 1 },
466  *	     // Link[1]: Input_0 <- Cluster0_Funnel0:Output_0
467  *	     Package () { 0, 0, \_SB_.CLU0.FUN0, 0 },
468  *	     // Link[2]: Input_1 <- Cluster1_Funnel0:Output_0
469  *	      Package () { 1, 0, \_SB_.CLU1.FUN0, 0 },
470  *	  }	// End of Graph[0] Package
471  *
472  *	}, // End of ACPI Graph Property
473  *  })
474  */
475 static inline bool acpi_validate_dsd_graph(const union acpi_object *graph)
476 {
477 	int i, n;
478 	const union acpi_object *rev, *nr_graphs;
479 
480 	/* The graph must contain at least the Revision and Number of Graphs */
481 	if (graph->package.count < 2)
482 		return false;
483 
484 	rev = &graph->package.elements[0];
485 	nr_graphs = &graph->package.elements[1];
486 
487 	if (rev->type != ACPI_TYPE_INTEGER ||
488 	    nr_graphs->type != ACPI_TYPE_INTEGER)
489 		return false;
490 
491 	/* We only support revision 0 */
492 	if (rev->integer.value != 0)
493 		return false;
494 
495 	n = nr_graphs->integer.value;
496 	/* CoreSight devices are only part of a single Graph */
497 	if (n != 1)
498 		return false;
499 
500 	/* Make sure the ACPI graph package has right number of elements */
501 	if (graph->package.count != (n + 2))
502 		return false;
503 
504 	/*
505 	 * Each entry must be a graph package with at least 3 members :
506 	 * { GraphID, UUID, NumberOfLinks(n), Links[.],... }
507 	 */
508 	for (i = 2; i < n + 2; i++) {
509 		const union acpi_object *obj = &graph->package.elements[i];
510 
511 		if (obj->type != ACPI_TYPE_PACKAGE ||
512 		    obj->package.count < 3)
513 			return false;
514 	}
515 
516 	return true;
517 }
518 
519 /* acpi_get_dsd_graph	- Find the _DSD Graph property for the given device. */
520 static const union acpi_object *
521 acpi_get_dsd_graph(struct acpi_device *adev)
522 {
523 	int i;
524 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
525 	acpi_status status;
526 	const union acpi_object *dsd;
527 
528 	status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL,
529 					    &buf, ACPI_TYPE_PACKAGE);
530 	if (ACPI_FAILURE(status))
531 		return NULL;
532 
533 	dsd = buf.pointer;
534 
535 	/*
536 	 * _DSD property consists tuples { Prop_UUID, Package() }
537 	 * Iterate through all the packages and find the Graph.
538 	 */
539 	for (i = 0; i + 1 < dsd->package.count; i += 2) {
540 		const union acpi_object *guid, *package;
541 
542 		guid = &dsd->package.elements[i];
543 		package = &dsd->package.elements[i + 1];
544 
545 		/* All _DSD elements must have a UUID and a Package */
546 		if (!is_acpi_guid(guid) || package->type != ACPI_TYPE_PACKAGE)
547 			break;
548 		/* Skip the non-Graph _DSD packages */
549 		if (!is_acpi_dsd_graph_guid(guid))
550 			continue;
551 		if (acpi_validate_dsd_graph(package))
552 			return package;
553 		/* Invalid graph format, continue */
554 		dev_warn(&adev->dev, "Invalid Graph _DSD property\n");
555 	}
556 
557 	return NULL;
558 }
559 
560 static inline bool
561 acpi_validate_coresight_graph(const union acpi_object *cs_graph)
562 {
563 	int nlinks;
564 
565 	nlinks = cs_graph->package.elements[2].integer.value;
566 	/*
567 	 * Graph must have the following fields :
568 	 * { GraphID, GraphUUID, NumberOfLinks, Links... }
569 	 */
570 	if (cs_graph->package.count != (nlinks + 3))
571 		return false;
572 	/* The links are validated in acpi_coresight_parse_link() */
573 	return true;
574 }
575 
576 /*
577  * acpi_get_coresight_graph	- Parse the device _DSD tables and find
578  * the Graph property matching the CoreSight Graphs.
579  *
580  * Returns the pointer to the CoreSight Graph Package when found. Otherwise
581  * returns NULL.
582  */
583 static const union acpi_object *
584 acpi_get_coresight_graph(struct acpi_device *adev)
585 {
586 	const union acpi_object *graph_list, *graph;
587 	int i, nr_graphs;
588 
589 	graph_list = acpi_get_dsd_graph(adev);
590 	if (!graph_list)
591 		return graph_list;
592 
593 	nr_graphs = graph_list->package.elements[1].integer.value;
594 
595 	for (i = 2; i < nr_graphs + 2; i++) {
596 		graph = &graph_list->package.elements[i];
597 		if (!is_acpi_coresight_graph(graph))
598 			continue;
599 		if (acpi_validate_coresight_graph(graph))
600 			return graph;
601 		/* Invalid graph format */
602 		break;
603 	}
604 
605 	return NULL;
606 }
607 
608 /*
609  * acpi_coresight_parse_link	- Parse the given Graph connection
610  * of the device and populate the coresight_connection for an output
611  * connection.
612  *
613  * CoreSight Graph specification mandates that the direction of the data
614  * flow must be specified in the link. i.e,
615  *
616  *	SourcePortAddress,	// Integer
617  *	DestinationPortAddress,	// Integer
618  *	DestinationDeviceName,	// Reference to another device
619  *	DirectionOfFlow,	// 1 for output(master), 0 for input(slave)
620  *
621  * Returns the direction of the data flow [ Input(slave) or Output(master) ]
622  * upon success.
623  * Returns an negative error number otherwise.
624  */
625 static int acpi_coresight_parse_link(struct acpi_device *adev,
626 				     const union acpi_object *link,
627 				     struct coresight_connection *conn)
628 {
629 	int rc, dir;
630 	const union acpi_object *fields;
631 	struct acpi_device *r_adev;
632 	struct device *rdev;
633 
634 	if (link->type != ACPI_TYPE_PACKAGE ||
635 	    link->package.count != 4)
636 		return -EINVAL;
637 
638 	fields = link->package.elements;
639 
640 	if (fields[0].type != ACPI_TYPE_INTEGER ||
641 	    fields[1].type != ACPI_TYPE_INTEGER ||
642 	    fields[2].type != ACPI_TYPE_LOCAL_REFERENCE ||
643 	    fields[3].type != ACPI_TYPE_INTEGER)
644 		return -EINVAL;
645 
646 	rc = acpi_bus_get_device(fields[2].reference.handle, &r_adev);
647 	if (rc)
648 		return rc;
649 
650 	dir = fields[3].integer.value;
651 	if (dir == ACPI_CORESIGHT_LINK_MASTER) {
652 		conn->outport = fields[0].integer.value;
653 		conn->child_port = fields[1].integer.value;
654 		rdev = coresight_find_device_by_fwnode(&r_adev->fwnode);
655 		if (!rdev)
656 			return -EPROBE_DEFER;
657 		/*
658 		 * Hold the refcount to the target device. This could be
659 		 * released via:
660 		 * 1) coresight_release_platform_data() if the probe fails or
661 		 *    this device is unregistered.
662 		 * 2) While removing the target device via
663 		 *    coresight_remove_match().
664 		 */
665 		conn->child_fwnode = fwnode_handle_get(&r_adev->fwnode);
666 	} else if (dir == ACPI_CORESIGHT_LINK_SLAVE) {
667 		/*
668 		 * We are only interested in the port number
669 		 * for the input ports at this component.
670 		 * Store the port number in child_port.
671 		 */
672 		conn->child_port = fields[0].integer.value;
673 	} else {
674 		/* Invalid direction */
675 		return -EINVAL;
676 	}
677 
678 	return dir;
679 }
680 
681 /*
682  * acpi_coresight_parse_graph	- Parse the _DSD CoreSight graph
683  * connection information and populate the supplied coresight_platform_data
684  * instance.
685  */
686 static int acpi_coresight_parse_graph(struct acpi_device *adev,
687 				      struct coresight_platform_data *pdata)
688 {
689 	int rc, i, nlinks;
690 	const union acpi_object *graph;
691 	struct coresight_connection *conns, *ptr;
692 
693 	pdata->nr_inport = pdata->nr_outport = 0;
694 	graph = acpi_get_coresight_graph(adev);
695 	if (!graph)
696 		return -ENOENT;
697 
698 	nlinks = graph->package.elements[2].integer.value;
699 	if (!nlinks)
700 		return 0;
701 
702 	/*
703 	 * To avoid scanning the table twice (once for finding the number of
704 	 * output links and then later for parsing the output links),
705 	 * cache the links information in one go and then later copy
706 	 * it to the pdata.
707 	 */
708 	conns = devm_kcalloc(&adev->dev, nlinks, sizeof(*conns), GFP_KERNEL);
709 	if (!conns)
710 		return -ENOMEM;
711 	ptr = conns;
712 	for (i = 0; i < nlinks; i++) {
713 		const union acpi_object *link = &graph->package.elements[3 + i];
714 		int dir;
715 
716 		dir = acpi_coresight_parse_link(adev, link, ptr);
717 		if (dir < 0)
718 			return dir;
719 
720 		if (dir == ACPI_CORESIGHT_LINK_MASTER) {
721 			if (ptr->outport >= pdata->nr_outport)
722 				pdata->nr_outport = ptr->outport + 1;
723 			ptr++;
724 		} else {
725 			WARN_ON(pdata->nr_inport == ptr->child_port + 1);
726 			/*
727 			 * We do not track input port connections for a device.
728 			 * However we need the highest port number described,
729 			 * which can be recorded now and reuse this connection
730 			 * record for an output connection. Hence, do not move
731 			 * the ptr for input connections
732 			 */
733 			if (ptr->child_port >= pdata->nr_inport)
734 				pdata->nr_inport = ptr->child_port + 1;
735 		}
736 	}
737 
738 	rc = coresight_alloc_conns(&adev->dev, pdata);
739 	if (rc)
740 		return rc;
741 
742 	/* Copy the connection information to the final location */
743 	for (i = 0; conns + i < ptr; i++) {
744 		int port = conns[i].outport;
745 
746 		/* Duplicate output port */
747 		WARN_ON(pdata->conns[port].child_fwnode);
748 		pdata->conns[port] = conns[i];
749 	}
750 
751 	devm_kfree(&adev->dev, conns);
752 	return 0;
753 }
754 
755 /*
756  * acpi_handle_to_logical_cpuid - Map a given acpi_handle to the
757  * logical CPU id of the corresponding CPU device.
758  *
759  * Returns the logical CPU id when found. Otherwise returns >= nr_cpus_id.
760  */
761 static int
762 acpi_handle_to_logical_cpuid(acpi_handle handle)
763 {
764 	int i;
765 	struct acpi_processor *pr;
766 
767 	for_each_possible_cpu(i) {
768 		pr = per_cpu(processors, i);
769 		if (pr && pr->handle == handle)
770 			break;
771 	}
772 
773 	return i;
774 }
775 
776 /*
777  * acpi_coresigh_get_cpu - Find the logical CPU id of the CPU associated
778  * with this coresight device. With ACPI bindings, the CoreSight components
779  * are listed as child device of the associated CPU.
780  *
781  * Returns the logical CPU id when found. Otherwise returns 0.
782  */
783 static int acpi_coresight_get_cpu(struct device *dev)
784 {
785 	int cpu;
786 	acpi_handle cpu_handle;
787 	acpi_status status;
788 	struct acpi_device *adev = ACPI_COMPANION(dev);
789 
790 	if (!adev)
791 		return -ENODEV;
792 	status = acpi_get_parent(adev->handle, &cpu_handle);
793 	if (ACPI_FAILURE(status))
794 		return -ENODEV;
795 
796 	cpu = acpi_handle_to_logical_cpuid(cpu_handle);
797 	if (cpu >= nr_cpu_ids)
798 		return -ENODEV;
799 	return cpu;
800 }
801 
802 static int
803 acpi_get_coresight_platform_data(struct device *dev,
804 				 struct coresight_platform_data *pdata)
805 {
806 	struct acpi_device *adev;
807 
808 	adev = ACPI_COMPANION(dev);
809 	if (!adev)
810 		return -EINVAL;
811 
812 	return acpi_coresight_parse_graph(adev, pdata);
813 }
814 
815 #else
816 
817 static inline int
818 acpi_get_coresight_platform_data(struct device *dev,
819 				 struct coresight_platform_data *pdata)
820 {
821 	return -ENOENT;
822 }
823 
824 static inline int acpi_coresight_get_cpu(struct device *dev)
825 {
826 	return -ENODEV;
827 }
828 #endif
829 
830 int coresight_get_cpu(struct device *dev)
831 {
832 	if (is_of_node(dev->fwnode))
833 		return of_coresight_get_cpu(dev);
834 	else if (is_acpi_device_node(dev->fwnode))
835 		return acpi_coresight_get_cpu(dev);
836 	return 0;
837 }
838 EXPORT_SYMBOL_GPL(coresight_get_cpu);
839 
840 struct coresight_platform_data *
841 coresight_get_platform_data(struct device *dev)
842 {
843 	int ret = -ENOENT;
844 	struct coresight_platform_data *pdata = NULL;
845 	struct fwnode_handle *fwnode = dev_fwnode(dev);
846 
847 	if (IS_ERR_OR_NULL(fwnode))
848 		goto error;
849 
850 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
851 	if (!pdata) {
852 		ret = -ENOMEM;
853 		goto error;
854 	}
855 
856 	if (is_of_node(fwnode))
857 		ret = of_get_coresight_platform_data(dev, pdata);
858 	else if (is_acpi_device_node(fwnode))
859 		ret = acpi_get_coresight_platform_data(dev, pdata);
860 
861 	if (!ret)
862 		return pdata;
863 error:
864 	if (!IS_ERR_OR_NULL(pdata))
865 		/* Cleanup the connection information */
866 		coresight_release_platform_data(NULL, pdata);
867 	return ERR_PTR(ret);
868 }
869 EXPORT_SYMBOL_GPL(coresight_get_platform_data);
870