1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Procedures for creating, accessing and interpreting the device tree.
4  *
5  * Paul Mackerras	August 1996.
6  * Copyright (C) 1996-2005 Paul Mackerras.
7  *
8  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9  *    {engebret|bergner}@us.ibm.com
10  *
11  *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12  *
13  *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
14  *  Grant Likely.
15  */
16 
17 #define pr_fmt(fmt)	"OF: " fmt
18 
19 #include <linux/console.h>
20 #include <linux/ctype.h>
21 #include <linux/cpu.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/of_graph.h>
26 #include <linux/spinlock.h>
27 #include <linux/slab.h>
28 #include <linux/string.h>
29 #include <linux/proc_fs.h>
30 
31 #include "of_private.h"
32 
33 LIST_HEAD(aliases_lookup);
34 
35 struct device_node *of_root;
36 EXPORT_SYMBOL(of_root);
37 struct device_node *of_chosen;
38 EXPORT_SYMBOL(of_chosen);
39 struct device_node *of_aliases;
40 struct device_node *of_stdout;
41 static const char *of_stdout_options;
42 
43 struct kset *of_kset;
44 
45 /*
46  * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47  * This mutex must be held whenever modifications are being made to the
48  * device tree. The of_{attach,detach}_node() and
49  * of_{add,remove,update}_property() helpers make sure this happens.
50  */
51 DEFINE_MUTEX(of_mutex);
52 
53 /* use when traversing tree through the child, sibling,
54  * or parent members of struct device_node.
55  */
56 DEFINE_RAW_SPINLOCK(devtree_lock);
57 
of_node_name_eq(const struct device_node * np,const char * name)58 bool of_node_name_eq(const struct device_node *np, const char *name)
59 {
60 	const char *node_name;
61 	size_t len;
62 
63 	if (!np)
64 		return false;
65 
66 	node_name = kbasename(np->full_name);
67 	len = strchrnul(node_name, '@') - node_name;
68 
69 	return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70 }
71 EXPORT_SYMBOL(of_node_name_eq);
72 
of_node_name_prefix(const struct device_node * np,const char * prefix)73 bool of_node_name_prefix(const struct device_node *np, const char *prefix)
74 {
75 	if (!np)
76 		return false;
77 
78 	return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79 }
80 EXPORT_SYMBOL(of_node_name_prefix);
81 
__of_node_is_type(const struct device_node * np,const char * type)82 static bool __of_node_is_type(const struct device_node *np, const char *type)
83 {
84 	const char *match = __of_get_property(np, "device_type", NULL);
85 
86 	return np && match && type && !strcmp(match, type);
87 }
88 
of_bus_n_addr_cells(struct device_node * np)89 int of_bus_n_addr_cells(struct device_node *np)
90 {
91 	u32 cells;
92 
93 	for (; np; np = np->parent)
94 		if (!of_property_read_u32(np, "#address-cells", &cells))
95 			return cells;
96 
97 	/* No #address-cells property for the root node */
98 	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
99 }
100 
of_n_addr_cells(struct device_node * np)101 int of_n_addr_cells(struct device_node *np)
102 {
103 	if (np->parent)
104 		np = np->parent;
105 
106 	return of_bus_n_addr_cells(np);
107 }
108 EXPORT_SYMBOL(of_n_addr_cells);
109 
of_bus_n_size_cells(struct device_node * np)110 int of_bus_n_size_cells(struct device_node *np)
111 {
112 	u32 cells;
113 
114 	for (; np; np = np->parent)
115 		if (!of_property_read_u32(np, "#size-cells", &cells))
116 			return cells;
117 
118 	/* No #size-cells property for the root node */
119 	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
120 }
121 
of_n_size_cells(struct device_node * np)122 int of_n_size_cells(struct device_node *np)
123 {
124 	if (np->parent)
125 		np = np->parent;
126 
127 	return of_bus_n_size_cells(np);
128 }
129 EXPORT_SYMBOL(of_n_size_cells);
130 
131 #ifdef CONFIG_NUMA
of_node_to_nid(struct device_node * np)132 int __weak of_node_to_nid(struct device_node *np)
133 {
134 	return NUMA_NO_NODE;
135 }
136 #endif
137 
138 #define OF_PHANDLE_CACHE_BITS	7
139 #define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
140 
141 static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142 
of_phandle_cache_hash(phandle handle)143 static u32 of_phandle_cache_hash(phandle handle)
144 {
145 	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
146 }
147 
148 /*
149  * Caller must hold devtree_lock.
150  */
__of_phandle_cache_inv_entry(phandle handle)151 void __of_phandle_cache_inv_entry(phandle handle)
152 {
153 	u32 handle_hash;
154 	struct device_node *np;
155 
156 	if (!handle)
157 		return;
158 
159 	handle_hash = of_phandle_cache_hash(handle);
160 
161 	np = phandle_cache[handle_hash];
162 	if (np && handle == np->phandle)
163 		phandle_cache[handle_hash] = NULL;
164 }
165 
of_core_init(void)166 void __init of_core_init(void)
167 {
168 	struct device_node *np;
169 
170 
171 	/* Create the kset, and register existing nodes */
172 	mutex_lock(&of_mutex);
173 	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
174 	if (!of_kset) {
175 		mutex_unlock(&of_mutex);
176 		pr_err("failed to register existing nodes\n");
177 		return;
178 	}
179 	for_each_of_allnodes(np) {
180 		__of_attach_node_sysfs(np);
181 		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
182 			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
183 	}
184 	mutex_unlock(&of_mutex);
185 
186 	/* Symlink in /proc as required by userspace ABI */
187 	if (of_root)
188 		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
189 }
190 
__of_find_property(const struct device_node * np,const char * name,int * lenp)191 static struct property *__of_find_property(const struct device_node *np,
192 					   const char *name, int *lenp)
193 {
194 	struct property *pp;
195 
196 	if (!np)
197 		return NULL;
198 
199 	for (pp = np->properties; pp; pp = pp->next) {
200 		if (of_prop_cmp(pp->name, name) == 0) {
201 			if (lenp)
202 				*lenp = pp->length;
203 			break;
204 		}
205 	}
206 
207 	return pp;
208 }
209 
of_find_property(const struct device_node * np,const char * name,int * lenp)210 struct property *of_find_property(const struct device_node *np,
211 				  const char *name,
212 				  int *lenp)
213 {
214 	struct property *pp;
215 	unsigned long flags;
216 
217 	raw_spin_lock_irqsave(&devtree_lock, flags);
218 	pp = __of_find_property(np, name, lenp);
219 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
220 
221 	return pp;
222 }
223 EXPORT_SYMBOL(of_find_property);
224 
__of_find_all_nodes(struct device_node * prev)225 struct device_node *__of_find_all_nodes(struct device_node *prev)
226 {
227 	struct device_node *np;
228 	if (!prev) {
229 		np = of_root;
230 	} else if (prev->child) {
231 		np = prev->child;
232 	} else {
233 		/* Walk back up looking for a sibling, or the end of the structure */
234 		np = prev;
235 		while (np->parent && !np->sibling)
236 			np = np->parent;
237 		np = np->sibling; /* Might be null at the end of the tree */
238 	}
239 	return np;
240 }
241 
242 /**
243  * of_find_all_nodes - Get next node in global list
244  * @prev:	Previous node or NULL to start iteration
245  *		of_node_put() will be called on it
246  *
247  * Return: A node pointer with refcount incremented, use
248  * of_node_put() on it when done.
249  */
of_find_all_nodes(struct device_node * prev)250 struct device_node *of_find_all_nodes(struct device_node *prev)
251 {
252 	struct device_node *np;
253 	unsigned long flags;
254 
255 	raw_spin_lock_irqsave(&devtree_lock, flags);
256 	np = __of_find_all_nodes(prev);
257 	of_node_get(np);
258 	of_node_put(prev);
259 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
260 	return np;
261 }
262 EXPORT_SYMBOL(of_find_all_nodes);
263 
264 /*
265  * Find a property with a given name for a given node
266  * and return the value.
267  */
__of_get_property(const struct device_node * np,const char * name,int * lenp)268 const void *__of_get_property(const struct device_node *np,
269 			      const char *name, int *lenp)
270 {
271 	struct property *pp = __of_find_property(np, name, lenp);
272 
273 	return pp ? pp->value : NULL;
274 }
275 
276 /*
277  * Find a property with a given name for a given node
278  * and return the value.
279  */
of_get_property(const struct device_node * np,const char * name,int * lenp)280 const void *of_get_property(const struct device_node *np, const char *name,
281 			    int *lenp)
282 {
283 	struct property *pp = of_find_property(np, name, lenp);
284 
285 	return pp ? pp->value : NULL;
286 }
287 EXPORT_SYMBOL(of_get_property);
288 
289 /**
290  * of_get_cpu_hwid - Get the hardware ID from a CPU device node
291  *
292  * @cpun: CPU number(logical index) for which device node is required
293  * @thread: The local thread number to get the hardware ID for.
294  *
295  * Return: The hardware ID for the CPU node or ~0ULL if not found.
296  */
of_get_cpu_hwid(struct device_node * cpun,unsigned int thread)297 u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
298 {
299 	const __be32 *cell;
300 	int ac, len;
301 
302 	ac = of_n_addr_cells(cpun);
303 	cell = of_get_property(cpun, "reg", &len);
304 	if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
305 		return ~0ULL;
306 
307 	cell += ac * thread;
308 	return of_read_number(cell, ac);
309 }
310 
311 /*
312  * arch_match_cpu_phys_id - Match the given logical CPU and physical id
313  *
314  * @cpu: logical cpu index of a core/thread
315  * @phys_id: physical identifier of a core/thread
316  *
317  * CPU logical to physical index mapping is architecture specific.
318  * However this __weak function provides a default match of physical
319  * id to logical cpu index. phys_id provided here is usually values read
320  * from the device tree which must match the hardware internal registers.
321  *
322  * Returns true if the physical identifier and the logical cpu index
323  * correspond to the same core/thread, false otherwise.
324  */
arch_match_cpu_phys_id(int cpu,u64 phys_id)325 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
326 {
327 	return (u32)phys_id == cpu;
328 }
329 
330 /*
331  * Checks if the given "prop_name" property holds the physical id of the
332  * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
333  * NULL, local thread number within the core is returned in it.
334  */
__of_find_n_match_cpu_property(struct device_node * cpun,const char * prop_name,int cpu,unsigned int * thread)335 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
336 			const char *prop_name, int cpu, unsigned int *thread)
337 {
338 	const __be32 *cell;
339 	int ac, prop_len, tid;
340 	u64 hwid;
341 
342 	ac = of_n_addr_cells(cpun);
343 	cell = of_get_property(cpun, prop_name, &prop_len);
344 	if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
345 		return true;
346 	if (!cell || !ac)
347 		return false;
348 	prop_len /= sizeof(*cell) * ac;
349 	for (tid = 0; tid < prop_len; tid++) {
350 		hwid = of_read_number(cell, ac);
351 		if (arch_match_cpu_phys_id(cpu, hwid)) {
352 			if (thread)
353 				*thread = tid;
354 			return true;
355 		}
356 		cell += ac;
357 	}
358 	return false;
359 }
360 
361 /*
362  * arch_find_n_match_cpu_physical_id - See if the given device node is
363  * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
364  * else false.  If 'thread' is non-NULL, the local thread number within the
365  * core is returned in it.
366  */
arch_find_n_match_cpu_physical_id(struct device_node * cpun,int cpu,unsigned int * thread)367 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
368 					      int cpu, unsigned int *thread)
369 {
370 	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
371 	 * for thread ids on PowerPC. If it doesn't exist fallback to
372 	 * standard "reg" property.
373 	 */
374 	if (IS_ENABLED(CONFIG_PPC) &&
375 	    __of_find_n_match_cpu_property(cpun,
376 					   "ibm,ppc-interrupt-server#s",
377 					   cpu, thread))
378 		return true;
379 
380 	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
381 }
382 
383 /**
384  * of_get_cpu_node - Get device node associated with the given logical CPU
385  *
386  * @cpu: CPU number(logical index) for which device node is required
387  * @thread: if not NULL, local thread number within the physical core is
388  *          returned
389  *
390  * The main purpose of this function is to retrieve the device node for the
391  * given logical CPU index. It should be used to initialize the of_node in
392  * cpu device. Once of_node in cpu device is populated, all the further
393  * references can use that instead.
394  *
395  * CPU logical to physical index mapping is architecture specific and is built
396  * before booting secondary cores. This function uses arch_match_cpu_phys_id
397  * which can be overridden by architecture specific implementation.
398  *
399  * Return: A node pointer for the logical cpu with refcount incremented, use
400  * of_node_put() on it when done. Returns NULL if not found.
401  */
of_get_cpu_node(int cpu,unsigned int * thread)402 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
403 {
404 	struct device_node *cpun;
405 
406 	for_each_of_cpu_node(cpun) {
407 		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
408 			return cpun;
409 	}
410 	return NULL;
411 }
412 EXPORT_SYMBOL(of_get_cpu_node);
413 
414 /**
415  * of_cpu_node_to_id: Get the logical CPU number for a given device_node
416  *
417  * @cpu_node: Pointer to the device_node for CPU.
418  *
419  * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
420  * CPU is not found.
421  */
of_cpu_node_to_id(struct device_node * cpu_node)422 int of_cpu_node_to_id(struct device_node *cpu_node)
423 {
424 	int cpu;
425 	bool found = false;
426 	struct device_node *np;
427 
428 	for_each_possible_cpu(cpu) {
429 		np = of_cpu_device_node_get(cpu);
430 		found = (cpu_node == np);
431 		of_node_put(np);
432 		if (found)
433 			return cpu;
434 	}
435 
436 	return -ENODEV;
437 }
438 EXPORT_SYMBOL(of_cpu_node_to_id);
439 
440 /**
441  * of_get_cpu_state_node - Get CPU's idle state node at the given index
442  *
443  * @cpu_node: The device node for the CPU
444  * @index: The index in the list of the idle states
445  *
446  * Two generic methods can be used to describe a CPU's idle states, either via
447  * a flattened description through the "cpu-idle-states" binding or via the
448  * hierarchical layout, using the "power-domains" and the "domain-idle-states"
449  * bindings. This function check for both and returns the idle state node for
450  * the requested index.
451  *
452  * Return: An idle state node if found at @index. The refcount is incremented
453  * for it, so call of_node_put() on it when done. Returns NULL if not found.
454  */
of_get_cpu_state_node(struct device_node * cpu_node,int index)455 struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
456 					  int index)
457 {
458 	struct of_phandle_args args;
459 	int err;
460 
461 	err = of_parse_phandle_with_args(cpu_node, "power-domains",
462 					"#power-domain-cells", 0, &args);
463 	if (!err) {
464 		struct device_node *state_node =
465 			of_parse_phandle(args.np, "domain-idle-states", index);
466 
467 		of_node_put(args.np);
468 		if (state_node)
469 			return state_node;
470 	}
471 
472 	return of_parse_phandle(cpu_node, "cpu-idle-states", index);
473 }
474 EXPORT_SYMBOL(of_get_cpu_state_node);
475 
476 /**
477  * __of_device_is_compatible() - Check if the node matches given constraints
478  * @device: pointer to node
479  * @compat: required compatible string, NULL or "" for any match
480  * @type: required device_type value, NULL or "" for any match
481  * @name: required node name, NULL or "" for any match
482  *
483  * Checks if the given @compat, @type and @name strings match the
484  * properties of the given @device. A constraints can be skipped by
485  * passing NULL or an empty string as the constraint.
486  *
487  * Returns 0 for no match, and a positive integer on match. The return
488  * value is a relative score with larger values indicating better
489  * matches. The score is weighted for the most specific compatible value
490  * to get the highest score. Matching type is next, followed by matching
491  * name. Practically speaking, this results in the following priority
492  * order for matches:
493  *
494  * 1. specific compatible && type && name
495  * 2. specific compatible && type
496  * 3. specific compatible && name
497  * 4. specific compatible
498  * 5. general compatible && type && name
499  * 6. general compatible && type
500  * 7. general compatible && name
501  * 8. general compatible
502  * 9. type && name
503  * 10. type
504  * 11. name
505  */
__of_device_is_compatible(const struct device_node * device,const char * compat,const char * type,const char * name)506 static int __of_device_is_compatible(const struct device_node *device,
507 				     const char *compat, const char *type, const char *name)
508 {
509 	struct property *prop;
510 	const char *cp;
511 	int index = 0, score = 0;
512 
513 	/* Compatible match has highest priority */
514 	if (compat && compat[0]) {
515 		prop = __of_find_property(device, "compatible", NULL);
516 		for (cp = of_prop_next_string(prop, NULL); cp;
517 		     cp = of_prop_next_string(prop, cp), index++) {
518 			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
519 				score = INT_MAX/2 - (index << 2);
520 				break;
521 			}
522 		}
523 		if (!score)
524 			return 0;
525 	}
526 
527 	/* Matching type is better than matching name */
528 	if (type && type[0]) {
529 		if (!__of_node_is_type(device, type))
530 			return 0;
531 		score += 2;
532 	}
533 
534 	/* Matching name is a bit better than not */
535 	if (name && name[0]) {
536 		if (!of_node_name_eq(device, name))
537 			return 0;
538 		score++;
539 	}
540 
541 	return score;
542 }
543 
544 /** Checks if the given "compat" string matches one of the strings in
545  * the device's "compatible" property
546  */
of_device_is_compatible(const struct device_node * device,const char * compat)547 int of_device_is_compatible(const struct device_node *device,
548 		const char *compat)
549 {
550 	unsigned long flags;
551 	int res;
552 
553 	raw_spin_lock_irqsave(&devtree_lock, flags);
554 	res = __of_device_is_compatible(device, compat, NULL, NULL);
555 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
556 	return res;
557 }
558 EXPORT_SYMBOL(of_device_is_compatible);
559 
560 /** Checks if the device is compatible with any of the entries in
561  *  a NULL terminated array of strings. Returns the best match
562  *  score or 0.
563  */
of_device_compatible_match(const struct device_node * device,const char * const * compat)564 int of_device_compatible_match(const struct device_node *device,
565 			       const char *const *compat)
566 {
567 	unsigned int tmp, score = 0;
568 
569 	if (!compat)
570 		return 0;
571 
572 	while (*compat) {
573 		tmp = of_device_is_compatible(device, *compat);
574 		if (tmp > score)
575 			score = tmp;
576 		compat++;
577 	}
578 
579 	return score;
580 }
581 EXPORT_SYMBOL_GPL(of_device_compatible_match);
582 
583 /**
584  * of_machine_is_compatible - Test root of device tree for a given compatible value
585  * @compat: compatible string to look for in root node's compatible property.
586  *
587  * Return: A positive integer if the root node has the given value in its
588  * compatible property.
589  */
of_machine_is_compatible(const char * compat)590 int of_machine_is_compatible(const char *compat)
591 {
592 	struct device_node *root;
593 	int rc = 0;
594 
595 	root = of_find_node_by_path("/");
596 	if (root) {
597 		rc = of_device_is_compatible(root, compat);
598 		of_node_put(root);
599 	}
600 	return rc;
601 }
602 EXPORT_SYMBOL(of_machine_is_compatible);
603 
604 /**
605  *  __of_device_is_available - check if a device is available for use
606  *
607  *  @device: Node to check for availability, with locks already held
608  *
609  *  Return: True if the status property is absent or set to "okay" or "ok",
610  *  false otherwise
611  */
__of_device_is_available(const struct device_node * device)612 static bool __of_device_is_available(const struct device_node *device)
613 {
614 	const char *status;
615 	int statlen;
616 
617 	if (!device)
618 		return false;
619 
620 	status = __of_get_property(device, "status", &statlen);
621 	if (status == NULL)
622 		return true;
623 
624 	if (statlen > 0) {
625 		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
626 			return true;
627 	}
628 
629 	return false;
630 }
631 
632 /**
633  *  of_device_is_available - check if a device is available for use
634  *
635  *  @device: Node to check for availability
636  *
637  *  Return: True if the status property is absent or set to "okay" or "ok",
638  *  false otherwise
639  */
of_device_is_available(const struct device_node * device)640 bool of_device_is_available(const struct device_node *device)
641 {
642 	unsigned long flags;
643 	bool res;
644 
645 	raw_spin_lock_irqsave(&devtree_lock, flags);
646 	res = __of_device_is_available(device);
647 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
648 	return res;
649 
650 }
651 EXPORT_SYMBOL(of_device_is_available);
652 
653 /**
654  *  __of_device_is_fail - check if a device has status "fail" or "fail-..."
655  *
656  *  @device: Node to check status for, with locks already held
657  *
658  *  Return: True if the status property is set to "fail" or "fail-..." (for any
659  *  error code suffix), false otherwise
660  */
__of_device_is_fail(const struct device_node * device)661 static bool __of_device_is_fail(const struct device_node *device)
662 {
663 	const char *status;
664 
665 	if (!device)
666 		return false;
667 
668 	status = __of_get_property(device, "status", NULL);
669 	if (status == NULL)
670 		return false;
671 
672 	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
673 }
674 
675 /**
676  *  of_device_is_big_endian - check if a device has BE registers
677  *
678  *  @device: Node to check for endianness
679  *
680  *  Return: True if the device has a "big-endian" property, or if the kernel
681  *  was compiled for BE *and* the device has a "native-endian" property.
682  *  Returns false otherwise.
683  *
684  *  Callers would nominally use ioread32be/iowrite32be if
685  *  of_device_is_big_endian() == true, or readl/writel otherwise.
686  */
of_device_is_big_endian(const struct device_node * device)687 bool of_device_is_big_endian(const struct device_node *device)
688 {
689 	if (of_property_read_bool(device, "big-endian"))
690 		return true;
691 	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
692 	    of_property_read_bool(device, "native-endian"))
693 		return true;
694 	return false;
695 }
696 EXPORT_SYMBOL(of_device_is_big_endian);
697 
698 /**
699  * of_get_parent - Get a node's parent if any
700  * @node:	Node to get parent
701  *
702  * Return: A node pointer with refcount incremented, use
703  * of_node_put() on it when done.
704  */
of_get_parent(const struct device_node * node)705 struct device_node *of_get_parent(const struct device_node *node)
706 {
707 	struct device_node *np;
708 	unsigned long flags;
709 
710 	if (!node)
711 		return NULL;
712 
713 	raw_spin_lock_irqsave(&devtree_lock, flags);
714 	np = of_node_get(node->parent);
715 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
716 	return np;
717 }
718 EXPORT_SYMBOL(of_get_parent);
719 
720 /**
721  * of_get_next_parent - Iterate to a node's parent
722  * @node:	Node to get parent of
723  *
724  * This is like of_get_parent() except that it drops the
725  * refcount on the passed node, making it suitable for iterating
726  * through a node's parents.
727  *
728  * Return: A node pointer with refcount incremented, use
729  * of_node_put() on it when done.
730  */
of_get_next_parent(struct device_node * node)731 struct device_node *of_get_next_parent(struct device_node *node)
732 {
733 	struct device_node *parent;
734 	unsigned long flags;
735 
736 	if (!node)
737 		return NULL;
738 
739 	raw_spin_lock_irqsave(&devtree_lock, flags);
740 	parent = of_node_get(node->parent);
741 	of_node_put(node);
742 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
743 	return parent;
744 }
745 EXPORT_SYMBOL(of_get_next_parent);
746 
__of_get_next_child(const struct device_node * node,struct device_node * prev)747 static struct device_node *__of_get_next_child(const struct device_node *node,
748 						struct device_node *prev)
749 {
750 	struct device_node *next;
751 
752 	if (!node)
753 		return NULL;
754 
755 	next = prev ? prev->sibling : node->child;
756 	of_node_get(next);
757 	of_node_put(prev);
758 	return next;
759 }
760 #define __for_each_child_of_node(parent, child) \
761 	for (child = __of_get_next_child(parent, NULL); child != NULL; \
762 	     child = __of_get_next_child(parent, child))
763 
764 /**
765  * of_get_next_child - Iterate a node childs
766  * @node:	parent node
767  * @prev:	previous child of the parent node, or NULL to get first
768  *
769  * Return: A node pointer with refcount incremented, use of_node_put() on
770  * it when done. Returns NULL when prev is the last child. Decrements the
771  * refcount of prev.
772  */
of_get_next_child(const struct device_node * node,struct device_node * prev)773 struct device_node *of_get_next_child(const struct device_node *node,
774 	struct device_node *prev)
775 {
776 	struct device_node *next;
777 	unsigned long flags;
778 
779 	raw_spin_lock_irqsave(&devtree_lock, flags);
780 	next = __of_get_next_child(node, prev);
781 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
782 	return next;
783 }
784 EXPORT_SYMBOL(of_get_next_child);
785 
786 /**
787  * of_get_next_available_child - Find the next available child node
788  * @node:	parent node
789  * @prev:	previous child of the parent node, or NULL to get first
790  *
791  * This function is like of_get_next_child(), except that it
792  * automatically skips any disabled nodes (i.e. status = "disabled").
793  */
of_get_next_available_child(const struct device_node * node,struct device_node * prev)794 struct device_node *of_get_next_available_child(const struct device_node *node,
795 	struct device_node *prev)
796 {
797 	struct device_node *next;
798 	unsigned long flags;
799 
800 	if (!node)
801 		return NULL;
802 
803 	raw_spin_lock_irqsave(&devtree_lock, flags);
804 	next = prev ? prev->sibling : node->child;
805 	for (; next; next = next->sibling) {
806 		if (!__of_device_is_available(next))
807 			continue;
808 		if (of_node_get(next))
809 			break;
810 	}
811 	of_node_put(prev);
812 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
813 	return next;
814 }
815 EXPORT_SYMBOL(of_get_next_available_child);
816 
817 /**
818  * of_get_next_cpu_node - Iterate on cpu nodes
819  * @prev:	previous child of the /cpus node, or NULL to get first
820  *
821  * Unusable CPUs (those with the status property set to "fail" or "fail-...")
822  * will be skipped.
823  *
824  * Return: A cpu node pointer with refcount incremented, use of_node_put()
825  * on it when done. Returns NULL when prev is the last child. Decrements
826  * the refcount of prev.
827  */
of_get_next_cpu_node(struct device_node * prev)828 struct device_node *of_get_next_cpu_node(struct device_node *prev)
829 {
830 	struct device_node *next = NULL;
831 	unsigned long flags;
832 	struct device_node *node;
833 
834 	if (!prev)
835 		node = of_find_node_by_path("/cpus");
836 
837 	raw_spin_lock_irqsave(&devtree_lock, flags);
838 	if (prev)
839 		next = prev->sibling;
840 	else if (node) {
841 		next = node->child;
842 		of_node_put(node);
843 	}
844 	for (; next; next = next->sibling) {
845 		if (__of_device_is_fail(next))
846 			continue;
847 		if (!(of_node_name_eq(next, "cpu") ||
848 		      __of_node_is_type(next, "cpu")))
849 			continue;
850 		if (of_node_get(next))
851 			break;
852 	}
853 	of_node_put(prev);
854 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
855 	return next;
856 }
857 EXPORT_SYMBOL(of_get_next_cpu_node);
858 
859 /**
860  * of_get_compatible_child - Find compatible child node
861  * @parent:	parent node
862  * @compatible:	compatible string
863  *
864  * Lookup child node whose compatible property contains the given compatible
865  * string.
866  *
867  * Return: a node pointer with refcount incremented, use of_node_put() on it
868  * when done; or NULL if not found.
869  */
of_get_compatible_child(const struct device_node * parent,const char * compatible)870 struct device_node *of_get_compatible_child(const struct device_node *parent,
871 				const char *compatible)
872 {
873 	struct device_node *child;
874 
875 	for_each_child_of_node(parent, child) {
876 		if (of_device_is_compatible(child, compatible))
877 			break;
878 	}
879 
880 	return child;
881 }
882 EXPORT_SYMBOL(of_get_compatible_child);
883 
884 /**
885  * of_get_child_by_name - Find the child node by name for a given parent
886  * @node:	parent node
887  * @name:	child name to look for.
888  *
889  * This function looks for child node for given matching name
890  *
891  * Return: A node pointer if found, with refcount incremented, use
892  * of_node_put() on it when done.
893  * Returns NULL if node is not found.
894  */
of_get_child_by_name(const struct device_node * node,const char * name)895 struct device_node *of_get_child_by_name(const struct device_node *node,
896 				const char *name)
897 {
898 	struct device_node *child;
899 
900 	for_each_child_of_node(node, child)
901 		if (of_node_name_eq(child, name))
902 			break;
903 	return child;
904 }
905 EXPORT_SYMBOL(of_get_child_by_name);
906 
__of_find_node_by_path(struct device_node * parent,const char * path)907 struct device_node *__of_find_node_by_path(struct device_node *parent,
908 						const char *path)
909 {
910 	struct device_node *child;
911 	int len;
912 
913 	len = strcspn(path, "/:");
914 	if (!len)
915 		return NULL;
916 
917 	__for_each_child_of_node(parent, child) {
918 		const char *name = kbasename(child->full_name);
919 		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
920 			return child;
921 	}
922 	return NULL;
923 }
924 
__of_find_node_by_full_path(struct device_node * node,const char * path)925 struct device_node *__of_find_node_by_full_path(struct device_node *node,
926 						const char *path)
927 {
928 	const char *separator = strchr(path, ':');
929 
930 	while (node && *path == '/') {
931 		struct device_node *tmp = node;
932 
933 		path++; /* Increment past '/' delimiter */
934 		node = __of_find_node_by_path(node, path);
935 		of_node_put(tmp);
936 		path = strchrnul(path, '/');
937 		if (separator && separator < path)
938 			break;
939 	}
940 	return node;
941 }
942 
943 /**
944  * of_find_node_opts_by_path - Find a node matching a full OF path
945  * @path: Either the full path to match, or if the path does not
946  *       start with '/', the name of a property of the /aliases
947  *       node (an alias).  In the case of an alias, the node
948  *       matching the alias' value will be returned.
949  * @opts: Address of a pointer into which to store the start of
950  *       an options string appended to the end of the path with
951  *       a ':' separator.
952  *
953  * Valid paths:
954  *  * /foo/bar	Full path
955  *  * foo	Valid alias
956  *  * foo/bar	Valid alias + relative path
957  *
958  * Return: A node pointer with refcount incremented, use
959  * of_node_put() on it when done.
960  */
of_find_node_opts_by_path(const char * path,const char ** opts)961 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
962 {
963 	struct device_node *np = NULL;
964 	struct property *pp;
965 	unsigned long flags;
966 	const char *separator = strchr(path, ':');
967 
968 	if (opts)
969 		*opts = separator ? separator + 1 : NULL;
970 
971 	if (strcmp(path, "/") == 0)
972 		return of_node_get(of_root);
973 
974 	/* The path could begin with an alias */
975 	if (*path != '/') {
976 		int len;
977 		const char *p = separator;
978 
979 		if (!p)
980 			p = strchrnul(path, '/');
981 		len = p - path;
982 
983 		/* of_aliases must not be NULL */
984 		if (!of_aliases)
985 			return NULL;
986 
987 		for_each_property_of_node(of_aliases, pp) {
988 			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
989 				np = of_find_node_by_path(pp->value);
990 				break;
991 			}
992 		}
993 		if (!np)
994 			return NULL;
995 		path = p;
996 	}
997 
998 	/* Step down the tree matching path components */
999 	raw_spin_lock_irqsave(&devtree_lock, flags);
1000 	if (!np)
1001 		np = of_node_get(of_root);
1002 	np = __of_find_node_by_full_path(np, path);
1003 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1004 	return np;
1005 }
1006 EXPORT_SYMBOL(of_find_node_opts_by_path);
1007 
1008 /**
1009  * of_find_node_by_name - Find a node by its "name" property
1010  * @from:	The node to start searching from or NULL; the node
1011  *		you pass will not be searched, only the next one
1012  *		will. Typically, you pass what the previous call
1013  *		returned. of_node_put() will be called on @from.
1014  * @name:	The name string to match against
1015  *
1016  * Return: A node pointer with refcount incremented, use
1017  * of_node_put() on it when done.
1018  */
of_find_node_by_name(struct device_node * from,const char * name)1019 struct device_node *of_find_node_by_name(struct device_node *from,
1020 	const char *name)
1021 {
1022 	struct device_node *np;
1023 	unsigned long flags;
1024 
1025 	raw_spin_lock_irqsave(&devtree_lock, flags);
1026 	for_each_of_allnodes_from(from, np)
1027 		if (of_node_name_eq(np, name) && of_node_get(np))
1028 			break;
1029 	of_node_put(from);
1030 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1031 	return np;
1032 }
1033 EXPORT_SYMBOL(of_find_node_by_name);
1034 
1035 /**
1036  * of_find_node_by_type - Find a node by its "device_type" property
1037  * @from:	The node to start searching from, or NULL to start searching
1038  *		the entire device tree. The node you pass will not be
1039  *		searched, only the next one will; typically, you pass
1040  *		what the previous call returned. of_node_put() will be
1041  *		called on from for you.
1042  * @type:	The type string to match against
1043  *
1044  * Return: A node pointer with refcount incremented, use
1045  * of_node_put() on it when done.
1046  */
of_find_node_by_type(struct device_node * from,const char * type)1047 struct device_node *of_find_node_by_type(struct device_node *from,
1048 	const char *type)
1049 {
1050 	struct device_node *np;
1051 	unsigned long flags;
1052 
1053 	raw_spin_lock_irqsave(&devtree_lock, flags);
1054 	for_each_of_allnodes_from(from, np)
1055 		if (__of_node_is_type(np, type) && of_node_get(np))
1056 			break;
1057 	of_node_put(from);
1058 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1059 	return np;
1060 }
1061 EXPORT_SYMBOL(of_find_node_by_type);
1062 
1063 /**
1064  * of_find_compatible_node - Find a node based on type and one of the
1065  *                                tokens in its "compatible" property
1066  * @from:	The node to start searching from or NULL, the node
1067  *		you pass will not be searched, only the next one
1068  *		will; typically, you pass what the previous call
1069  *		returned. of_node_put() will be called on it
1070  * @type:	The type string to match "device_type" or NULL to ignore
1071  * @compatible:	The string to match to one of the tokens in the device
1072  *		"compatible" list.
1073  *
1074  * Return: A node pointer with refcount incremented, use
1075  * of_node_put() on it when done.
1076  */
of_find_compatible_node(struct device_node * from,const char * type,const char * compatible)1077 struct device_node *of_find_compatible_node(struct device_node *from,
1078 	const char *type, const char *compatible)
1079 {
1080 	struct device_node *np;
1081 	unsigned long flags;
1082 
1083 	raw_spin_lock_irqsave(&devtree_lock, flags);
1084 	for_each_of_allnodes_from(from, np)
1085 		if (__of_device_is_compatible(np, compatible, type, NULL) &&
1086 		    of_node_get(np))
1087 			break;
1088 	of_node_put(from);
1089 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090 	return np;
1091 }
1092 EXPORT_SYMBOL(of_find_compatible_node);
1093 
1094 /**
1095  * of_find_node_with_property - Find a node which has a property with
1096  *                              the given name.
1097  * @from:	The node to start searching from or NULL, the node
1098  *		you pass will not be searched, only the next one
1099  *		will; typically, you pass what the previous call
1100  *		returned. of_node_put() will be called on it
1101  * @prop_name:	The name of the property to look for.
1102  *
1103  * Return: A node pointer with refcount incremented, use
1104  * of_node_put() on it when done.
1105  */
of_find_node_with_property(struct device_node * from,const char * prop_name)1106 struct device_node *of_find_node_with_property(struct device_node *from,
1107 	const char *prop_name)
1108 {
1109 	struct device_node *np;
1110 	struct property *pp;
1111 	unsigned long flags;
1112 
1113 	raw_spin_lock_irqsave(&devtree_lock, flags);
1114 	for_each_of_allnodes_from(from, np) {
1115 		for (pp = np->properties; pp; pp = pp->next) {
1116 			if (of_prop_cmp(pp->name, prop_name) == 0) {
1117 				of_node_get(np);
1118 				goto out;
1119 			}
1120 		}
1121 	}
1122 out:
1123 	of_node_put(from);
1124 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1125 	return np;
1126 }
1127 EXPORT_SYMBOL(of_find_node_with_property);
1128 
1129 static
__of_match_node(const struct of_device_id * matches,const struct device_node * node)1130 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1131 					   const struct device_node *node)
1132 {
1133 	const struct of_device_id *best_match = NULL;
1134 	int score, best_score = 0;
1135 
1136 	if (!matches)
1137 		return NULL;
1138 
1139 	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1140 		score = __of_device_is_compatible(node, matches->compatible,
1141 						  matches->type, matches->name);
1142 		if (score > best_score) {
1143 			best_match = matches;
1144 			best_score = score;
1145 		}
1146 	}
1147 
1148 	return best_match;
1149 }
1150 
1151 /**
1152  * of_match_node - Tell if a device_node has a matching of_match structure
1153  * @matches:	array of of device match structures to search in
1154  * @node:	the of device structure to match against
1155  *
1156  * Low level utility function used by device matching.
1157  */
of_match_node(const struct of_device_id * matches,const struct device_node * node)1158 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1159 					 const struct device_node *node)
1160 {
1161 	const struct of_device_id *match;
1162 	unsigned long flags;
1163 
1164 	raw_spin_lock_irqsave(&devtree_lock, flags);
1165 	match = __of_match_node(matches, node);
1166 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1167 	return match;
1168 }
1169 EXPORT_SYMBOL(of_match_node);
1170 
1171 /**
1172  * of_find_matching_node_and_match - Find a node based on an of_device_id
1173  *				     match table.
1174  * @from:	The node to start searching from or NULL, the node
1175  *		you pass will not be searched, only the next one
1176  *		will; typically, you pass what the previous call
1177  *		returned. of_node_put() will be called on it
1178  * @matches:	array of of device match structures to search in
1179  * @match:	Updated to point at the matches entry which matched
1180  *
1181  * Return: A node pointer with refcount incremented, use
1182  * of_node_put() on it when done.
1183  */
of_find_matching_node_and_match(struct device_node * from,const struct of_device_id * matches,const struct of_device_id ** match)1184 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1185 					const struct of_device_id *matches,
1186 					const struct of_device_id **match)
1187 {
1188 	struct device_node *np;
1189 	const struct of_device_id *m;
1190 	unsigned long flags;
1191 
1192 	if (match)
1193 		*match = NULL;
1194 
1195 	raw_spin_lock_irqsave(&devtree_lock, flags);
1196 	for_each_of_allnodes_from(from, np) {
1197 		m = __of_match_node(matches, np);
1198 		if (m && of_node_get(np)) {
1199 			if (match)
1200 				*match = m;
1201 			break;
1202 		}
1203 	}
1204 	of_node_put(from);
1205 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1206 	return np;
1207 }
1208 EXPORT_SYMBOL(of_find_matching_node_and_match);
1209 
1210 /**
1211  * of_modalias_node - Lookup appropriate modalias for a device node
1212  * @node:	pointer to a device tree node
1213  * @modalias:	Pointer to buffer that modalias value will be copied into
1214  * @len:	Length of modalias value
1215  *
1216  * Based on the value of the compatible property, this routine will attempt
1217  * to choose an appropriate modalias value for a particular device tree node.
1218  * It does this by stripping the manufacturer prefix (as delimited by a ',')
1219  * from the first entry in the compatible list property.
1220  *
1221  * Return: This routine returns 0 on success, <0 on failure.
1222  */
of_modalias_node(struct device_node * node,char * modalias,int len)1223 int of_modalias_node(struct device_node *node, char *modalias, int len)
1224 {
1225 	const char *compatible, *p;
1226 	int cplen;
1227 
1228 	compatible = of_get_property(node, "compatible", &cplen);
1229 	if (!compatible || strlen(compatible) > cplen)
1230 		return -ENODEV;
1231 	p = strchr(compatible, ',');
1232 	strscpy(modalias, p ? p + 1 : compatible, len);
1233 	return 0;
1234 }
1235 EXPORT_SYMBOL_GPL(of_modalias_node);
1236 
1237 /**
1238  * of_find_node_by_phandle - Find a node given a phandle
1239  * @handle:	phandle of the node to find
1240  *
1241  * Return: A node pointer with refcount incremented, use
1242  * of_node_put() on it when done.
1243  */
of_find_node_by_phandle(phandle handle)1244 struct device_node *of_find_node_by_phandle(phandle handle)
1245 {
1246 	struct device_node *np = NULL;
1247 	unsigned long flags;
1248 	u32 handle_hash;
1249 
1250 	if (!handle)
1251 		return NULL;
1252 
1253 	handle_hash = of_phandle_cache_hash(handle);
1254 
1255 	raw_spin_lock_irqsave(&devtree_lock, flags);
1256 
1257 	if (phandle_cache[handle_hash] &&
1258 	    handle == phandle_cache[handle_hash]->phandle)
1259 		np = phandle_cache[handle_hash];
1260 
1261 	if (!np) {
1262 		for_each_of_allnodes(np)
1263 			if (np->phandle == handle &&
1264 			    !of_node_check_flag(np, OF_DETACHED)) {
1265 				phandle_cache[handle_hash] = np;
1266 				break;
1267 			}
1268 	}
1269 
1270 	of_node_get(np);
1271 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1272 	return np;
1273 }
1274 EXPORT_SYMBOL(of_find_node_by_phandle);
1275 
of_print_phandle_args(const char * msg,const struct of_phandle_args * args)1276 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1277 {
1278 	int i;
1279 	printk("%s %pOF", msg, args->np);
1280 	for (i = 0; i < args->args_count; i++) {
1281 		const char delim = i ? ',' : ':';
1282 
1283 		pr_cont("%c%08x", delim, args->args[i]);
1284 	}
1285 	pr_cont("\n");
1286 }
1287 
of_phandle_iterator_init(struct of_phandle_iterator * it,const struct device_node * np,const char * list_name,const char * cells_name,int cell_count)1288 int of_phandle_iterator_init(struct of_phandle_iterator *it,
1289 		const struct device_node *np,
1290 		const char *list_name,
1291 		const char *cells_name,
1292 		int cell_count)
1293 {
1294 	const __be32 *list;
1295 	int size;
1296 
1297 	memset(it, 0, sizeof(*it));
1298 
1299 	/*
1300 	 * one of cell_count or cells_name must be provided to determine the
1301 	 * argument length.
1302 	 */
1303 	if (cell_count < 0 && !cells_name)
1304 		return -EINVAL;
1305 
1306 	list = of_get_property(np, list_name, &size);
1307 	if (!list)
1308 		return -ENOENT;
1309 
1310 	it->cells_name = cells_name;
1311 	it->cell_count = cell_count;
1312 	it->parent = np;
1313 	it->list_end = list + size / sizeof(*list);
1314 	it->phandle_end = list;
1315 	it->cur = list;
1316 
1317 	return 0;
1318 }
1319 EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1320 
of_phandle_iterator_next(struct of_phandle_iterator * it)1321 int of_phandle_iterator_next(struct of_phandle_iterator *it)
1322 {
1323 	uint32_t count = 0;
1324 
1325 	if (it->node) {
1326 		of_node_put(it->node);
1327 		it->node = NULL;
1328 	}
1329 
1330 	if (!it->cur || it->phandle_end >= it->list_end)
1331 		return -ENOENT;
1332 
1333 	it->cur = it->phandle_end;
1334 
1335 	/* If phandle is 0, then it is an empty entry with no arguments. */
1336 	it->phandle = be32_to_cpup(it->cur++);
1337 
1338 	if (it->phandle) {
1339 
1340 		/*
1341 		 * Find the provider node and parse the #*-cells property to
1342 		 * determine the argument length.
1343 		 */
1344 		it->node = of_find_node_by_phandle(it->phandle);
1345 
1346 		if (it->cells_name) {
1347 			if (!it->node) {
1348 				pr_err("%pOF: could not find phandle %d\n",
1349 				       it->parent, it->phandle);
1350 				goto err;
1351 			}
1352 
1353 			if (of_property_read_u32(it->node, it->cells_name,
1354 						 &count)) {
1355 				/*
1356 				 * If both cell_count and cells_name is given,
1357 				 * fall back to cell_count in absence
1358 				 * of the cells_name property
1359 				 */
1360 				if (it->cell_count >= 0) {
1361 					count = it->cell_count;
1362 				} else {
1363 					pr_err("%pOF: could not get %s for %pOF\n",
1364 					       it->parent,
1365 					       it->cells_name,
1366 					       it->node);
1367 					goto err;
1368 				}
1369 			}
1370 		} else {
1371 			count = it->cell_count;
1372 		}
1373 
1374 		/*
1375 		 * Make sure that the arguments actually fit in the remaining
1376 		 * property data length
1377 		 */
1378 		if (it->cur + count > it->list_end) {
1379 			if (it->cells_name)
1380 				pr_err("%pOF: %s = %d found %td\n",
1381 					it->parent, it->cells_name,
1382 					count, it->list_end - it->cur);
1383 			else
1384 				pr_err("%pOF: phandle %s needs %d, found %td\n",
1385 					it->parent, of_node_full_name(it->node),
1386 					count, it->list_end - it->cur);
1387 			goto err;
1388 		}
1389 	}
1390 
1391 	it->phandle_end = it->cur + count;
1392 	it->cur_count = count;
1393 
1394 	return 0;
1395 
1396 err:
1397 	if (it->node) {
1398 		of_node_put(it->node);
1399 		it->node = NULL;
1400 	}
1401 
1402 	return -EINVAL;
1403 }
1404 EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1405 
of_phandle_iterator_args(struct of_phandle_iterator * it,uint32_t * args,int size)1406 int of_phandle_iterator_args(struct of_phandle_iterator *it,
1407 			     uint32_t *args,
1408 			     int size)
1409 {
1410 	int i, count;
1411 
1412 	count = it->cur_count;
1413 
1414 	if (WARN_ON(size < count))
1415 		count = size;
1416 
1417 	for (i = 0; i < count; i++)
1418 		args[i] = be32_to_cpup(it->cur++);
1419 
1420 	return count;
1421 }
1422 
__of_parse_phandle_with_args(const struct device_node * np,const char * list_name,const char * cells_name,int cell_count,int index,struct of_phandle_args * out_args)1423 int __of_parse_phandle_with_args(const struct device_node *np,
1424 				 const char *list_name,
1425 				 const char *cells_name,
1426 				 int cell_count, int index,
1427 				 struct of_phandle_args *out_args)
1428 {
1429 	struct of_phandle_iterator it;
1430 	int rc, cur_index = 0;
1431 
1432 	if (index < 0)
1433 		return -EINVAL;
1434 
1435 	/* Loop over the phandles until all the requested entry is found */
1436 	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1437 		/*
1438 		 * All of the error cases bail out of the loop, so at
1439 		 * this point, the parsing is successful. If the requested
1440 		 * index matches, then fill the out_args structure and return,
1441 		 * or return -ENOENT for an empty entry.
1442 		 */
1443 		rc = -ENOENT;
1444 		if (cur_index == index) {
1445 			if (!it.phandle)
1446 				goto err;
1447 
1448 			if (out_args) {
1449 				int c;
1450 
1451 				c = of_phandle_iterator_args(&it,
1452 							     out_args->args,
1453 							     MAX_PHANDLE_ARGS);
1454 				out_args->np = it.node;
1455 				out_args->args_count = c;
1456 			} else {
1457 				of_node_put(it.node);
1458 			}
1459 
1460 			/* Found it! return success */
1461 			return 0;
1462 		}
1463 
1464 		cur_index++;
1465 	}
1466 
1467 	/*
1468 	 * Unlock node before returning result; will be one of:
1469 	 * -ENOENT : index is for empty phandle
1470 	 * -EINVAL : parsing error on data
1471 	 */
1472 
1473  err:
1474 	of_node_put(it.node);
1475 	return rc;
1476 }
1477 EXPORT_SYMBOL(__of_parse_phandle_with_args);
1478 
1479 /**
1480  * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1481  * @np:		pointer to a device tree node containing a list
1482  * @list_name:	property name that contains a list
1483  * @stem_name:	stem of property names that specify phandles' arguments count
1484  * @index:	index of a phandle to parse out
1485  * @out_args:	optional pointer to output arguments structure (will be filled)
1486  *
1487  * This function is useful to parse lists of phandles and their arguments.
1488  * Returns 0 on success and fills out_args, on error returns appropriate errno
1489  * value. The difference between this function and of_parse_phandle_with_args()
1490  * is that this API remaps a phandle if the node the phandle points to has
1491  * a <@stem_name>-map property.
1492  *
1493  * Caller is responsible to call of_node_put() on the returned out_args->np
1494  * pointer.
1495  *
1496  * Example::
1497  *
1498  *  phandle1: node1 {
1499  *  	#list-cells = <2>;
1500  *  };
1501  *
1502  *  phandle2: node2 {
1503  *  	#list-cells = <1>;
1504  *  };
1505  *
1506  *  phandle3: node3 {
1507  *  	#list-cells = <1>;
1508  *  	list-map = <0 &phandle2 3>,
1509  *  		   <1 &phandle2 2>,
1510  *  		   <2 &phandle1 5 1>;
1511  *  	list-map-mask = <0x3>;
1512  *  };
1513  *
1514  *  node4 {
1515  *  	list = <&phandle1 1 2 &phandle3 0>;
1516  *  };
1517  *
1518  * To get a device_node of the ``node2`` node you may call this:
1519  * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1520  */
of_parse_phandle_with_args_map(const struct device_node * np,const char * list_name,const char * stem_name,int index,struct of_phandle_args * out_args)1521 int of_parse_phandle_with_args_map(const struct device_node *np,
1522 				   const char *list_name,
1523 				   const char *stem_name,
1524 				   int index, struct of_phandle_args *out_args)
1525 {
1526 	char *cells_name, *map_name = NULL, *mask_name = NULL;
1527 	char *pass_name = NULL;
1528 	struct device_node *cur, *new = NULL;
1529 	const __be32 *map, *mask, *pass;
1530 	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1531 	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1532 	__be32 initial_match_array[MAX_PHANDLE_ARGS];
1533 	const __be32 *match_array = initial_match_array;
1534 	int i, ret, map_len, match;
1535 	u32 list_size, new_size;
1536 
1537 	if (index < 0)
1538 		return -EINVAL;
1539 
1540 	cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1541 	if (!cells_name)
1542 		return -ENOMEM;
1543 
1544 	ret = -ENOMEM;
1545 	map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1546 	if (!map_name)
1547 		goto free;
1548 
1549 	mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1550 	if (!mask_name)
1551 		goto free;
1552 
1553 	pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1554 	if (!pass_name)
1555 		goto free;
1556 
1557 	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1558 					   out_args);
1559 	if (ret)
1560 		goto free;
1561 
1562 	/* Get the #<list>-cells property */
1563 	cur = out_args->np;
1564 	ret = of_property_read_u32(cur, cells_name, &list_size);
1565 	if (ret < 0)
1566 		goto put;
1567 
1568 	/* Precalculate the match array - this simplifies match loop */
1569 	for (i = 0; i < list_size; i++)
1570 		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1571 
1572 	ret = -EINVAL;
1573 	while (cur) {
1574 		/* Get the <list>-map property */
1575 		map = of_get_property(cur, map_name, &map_len);
1576 		if (!map) {
1577 			ret = 0;
1578 			goto free;
1579 		}
1580 		map_len /= sizeof(u32);
1581 
1582 		/* Get the <list>-map-mask property (optional) */
1583 		mask = of_get_property(cur, mask_name, NULL);
1584 		if (!mask)
1585 			mask = dummy_mask;
1586 		/* Iterate through <list>-map property */
1587 		match = 0;
1588 		while (map_len > (list_size + 1) && !match) {
1589 			/* Compare specifiers */
1590 			match = 1;
1591 			for (i = 0; i < list_size; i++, map_len--)
1592 				match &= !((match_array[i] ^ *map++) & mask[i]);
1593 
1594 			of_node_put(new);
1595 			new = of_find_node_by_phandle(be32_to_cpup(map));
1596 			map++;
1597 			map_len--;
1598 
1599 			/* Check if not found */
1600 			if (!new)
1601 				goto put;
1602 
1603 			if (!of_device_is_available(new))
1604 				match = 0;
1605 
1606 			ret = of_property_read_u32(new, cells_name, &new_size);
1607 			if (ret)
1608 				goto put;
1609 
1610 			/* Check for malformed properties */
1611 			if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1612 				goto put;
1613 			if (map_len < new_size)
1614 				goto put;
1615 
1616 			/* Move forward by new node's #<list>-cells amount */
1617 			map += new_size;
1618 			map_len -= new_size;
1619 		}
1620 		if (!match)
1621 			goto put;
1622 
1623 		/* Get the <list>-map-pass-thru property (optional) */
1624 		pass = of_get_property(cur, pass_name, NULL);
1625 		if (!pass)
1626 			pass = dummy_pass;
1627 
1628 		/*
1629 		 * Successfully parsed a <list>-map translation; copy new
1630 		 * specifier into the out_args structure, keeping the
1631 		 * bits specified in <list>-map-pass-thru.
1632 		 */
1633 		match_array = map - new_size;
1634 		for (i = 0; i < new_size; i++) {
1635 			__be32 val = *(map - new_size + i);
1636 
1637 			if (i < list_size) {
1638 				val &= ~pass[i];
1639 				val |= cpu_to_be32(out_args->args[i]) & pass[i];
1640 			}
1641 
1642 			out_args->args[i] = be32_to_cpu(val);
1643 		}
1644 		out_args->args_count = list_size = new_size;
1645 		/* Iterate again with new provider */
1646 		out_args->np = new;
1647 		of_node_put(cur);
1648 		cur = new;
1649 	}
1650 put:
1651 	of_node_put(cur);
1652 	of_node_put(new);
1653 free:
1654 	kfree(mask_name);
1655 	kfree(map_name);
1656 	kfree(cells_name);
1657 	kfree(pass_name);
1658 
1659 	return ret;
1660 }
1661 EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1662 
1663 /**
1664  * of_count_phandle_with_args() - Find the number of phandles references in a property
1665  * @np:		pointer to a device tree node containing a list
1666  * @list_name:	property name that contains a list
1667  * @cells_name:	property name that specifies phandles' arguments count
1668  *
1669  * Return: The number of phandle + argument tuples within a property. It
1670  * is a typical pattern to encode a list of phandle and variable
1671  * arguments into a single property. The number of arguments is encoded
1672  * by a property in the phandle-target node. For example, a gpios
1673  * property would contain a list of GPIO specifies consisting of a
1674  * phandle and 1 or more arguments. The number of arguments are
1675  * determined by the #gpio-cells property in the node pointed to by the
1676  * phandle.
1677  */
of_count_phandle_with_args(const struct device_node * np,const char * list_name,const char * cells_name)1678 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1679 				const char *cells_name)
1680 {
1681 	struct of_phandle_iterator it;
1682 	int rc, cur_index = 0;
1683 
1684 	/*
1685 	 * If cells_name is NULL we assume a cell count of 0. This makes
1686 	 * counting the phandles trivial as each 32bit word in the list is a
1687 	 * phandle and no arguments are to consider. So we don't iterate through
1688 	 * the list but just use the length to determine the phandle count.
1689 	 */
1690 	if (!cells_name) {
1691 		const __be32 *list;
1692 		int size;
1693 
1694 		list = of_get_property(np, list_name, &size);
1695 		if (!list)
1696 			return -ENOENT;
1697 
1698 		return size / sizeof(*list);
1699 	}
1700 
1701 	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1702 	if (rc)
1703 		return rc;
1704 
1705 	while ((rc = of_phandle_iterator_next(&it)) == 0)
1706 		cur_index += 1;
1707 
1708 	if (rc != -ENOENT)
1709 		return rc;
1710 
1711 	return cur_index;
1712 }
1713 EXPORT_SYMBOL(of_count_phandle_with_args);
1714 
1715 /**
1716  * __of_add_property - Add a property to a node without lock operations
1717  * @np:		Caller's Device Node
1718  * @prop:	Property to add
1719  */
__of_add_property(struct device_node * np,struct property * prop)1720 int __of_add_property(struct device_node *np, struct property *prop)
1721 {
1722 	struct property **next;
1723 
1724 	prop->next = NULL;
1725 	next = &np->properties;
1726 	while (*next) {
1727 		if (strcmp(prop->name, (*next)->name) == 0)
1728 			/* duplicate ! don't insert it */
1729 			return -EEXIST;
1730 
1731 		next = &(*next)->next;
1732 	}
1733 	*next = prop;
1734 
1735 	return 0;
1736 }
1737 
1738 /**
1739  * of_add_property - Add a property to a node
1740  * @np:		Caller's Device Node
1741  * @prop:	Property to add
1742  */
of_add_property(struct device_node * np,struct property * prop)1743 int of_add_property(struct device_node *np, struct property *prop)
1744 {
1745 	unsigned long flags;
1746 	int rc;
1747 
1748 	mutex_lock(&of_mutex);
1749 
1750 	raw_spin_lock_irqsave(&devtree_lock, flags);
1751 	rc = __of_add_property(np, prop);
1752 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1753 
1754 	if (!rc)
1755 		__of_add_property_sysfs(np, prop);
1756 
1757 	mutex_unlock(&of_mutex);
1758 
1759 	if (!rc)
1760 		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1761 
1762 	return rc;
1763 }
1764 EXPORT_SYMBOL_GPL(of_add_property);
1765 
__of_remove_property(struct device_node * np,struct property * prop)1766 int __of_remove_property(struct device_node *np, struct property *prop)
1767 {
1768 	struct property **next;
1769 
1770 	for (next = &np->properties; *next; next = &(*next)->next) {
1771 		if (*next == prop)
1772 			break;
1773 	}
1774 	if (*next == NULL)
1775 		return -ENODEV;
1776 
1777 	/* found the node */
1778 	*next = prop->next;
1779 	prop->next = np->deadprops;
1780 	np->deadprops = prop;
1781 
1782 	return 0;
1783 }
1784 
1785 /**
1786  * of_remove_property - Remove a property from a node.
1787  * @np:		Caller's Device Node
1788  * @prop:	Property to remove
1789  *
1790  * Note that we don't actually remove it, since we have given out
1791  * who-knows-how-many pointers to the data using get-property.
1792  * Instead we just move the property to the "dead properties"
1793  * list, so it won't be found any more.
1794  */
of_remove_property(struct device_node * np,struct property * prop)1795 int of_remove_property(struct device_node *np, struct property *prop)
1796 {
1797 	unsigned long flags;
1798 	int rc;
1799 
1800 	if (!prop)
1801 		return -ENODEV;
1802 
1803 	mutex_lock(&of_mutex);
1804 
1805 	raw_spin_lock_irqsave(&devtree_lock, flags);
1806 	rc = __of_remove_property(np, prop);
1807 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1808 
1809 	if (!rc)
1810 		__of_remove_property_sysfs(np, prop);
1811 
1812 	mutex_unlock(&of_mutex);
1813 
1814 	if (!rc)
1815 		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1816 
1817 	return rc;
1818 }
1819 EXPORT_SYMBOL_GPL(of_remove_property);
1820 
__of_update_property(struct device_node * np,struct property * newprop,struct property ** oldpropp)1821 int __of_update_property(struct device_node *np, struct property *newprop,
1822 		struct property **oldpropp)
1823 {
1824 	struct property **next, *oldprop;
1825 
1826 	for (next = &np->properties; *next; next = &(*next)->next) {
1827 		if (of_prop_cmp((*next)->name, newprop->name) == 0)
1828 			break;
1829 	}
1830 	*oldpropp = oldprop = *next;
1831 
1832 	if (oldprop) {
1833 		/* replace the node */
1834 		newprop->next = oldprop->next;
1835 		*next = newprop;
1836 		oldprop->next = np->deadprops;
1837 		np->deadprops = oldprop;
1838 	} else {
1839 		/* new node */
1840 		newprop->next = NULL;
1841 		*next = newprop;
1842 	}
1843 
1844 	return 0;
1845 }
1846 
1847 /*
1848  * of_update_property - Update a property in a node, if the property does
1849  * not exist, add it.
1850  *
1851  * Note that we don't actually remove it, since we have given out
1852  * who-knows-how-many pointers to the data using get-property.
1853  * Instead we just move the property to the "dead properties" list,
1854  * and add the new property to the property list
1855  */
of_update_property(struct device_node * np,struct property * newprop)1856 int of_update_property(struct device_node *np, struct property *newprop)
1857 {
1858 	struct property *oldprop;
1859 	unsigned long flags;
1860 	int rc;
1861 
1862 	if (!newprop->name)
1863 		return -EINVAL;
1864 
1865 	mutex_lock(&of_mutex);
1866 
1867 	raw_spin_lock_irqsave(&devtree_lock, flags);
1868 	rc = __of_update_property(np, newprop, &oldprop);
1869 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1870 
1871 	if (!rc)
1872 		__of_update_property_sysfs(np, newprop, oldprop);
1873 
1874 	mutex_unlock(&of_mutex);
1875 
1876 	if (!rc)
1877 		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1878 
1879 	return rc;
1880 }
1881 
of_alias_add(struct alias_prop * ap,struct device_node * np,int id,const char * stem,int stem_len)1882 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1883 			 int id, const char *stem, int stem_len)
1884 {
1885 	ap->np = np;
1886 	ap->id = id;
1887 	strncpy(ap->stem, stem, stem_len);
1888 	ap->stem[stem_len] = 0;
1889 	list_add_tail(&ap->link, &aliases_lookup);
1890 	pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1891 		 ap->alias, ap->stem, ap->id, np);
1892 }
1893 
1894 /**
1895  * of_alias_scan - Scan all properties of the 'aliases' node
1896  * @dt_alloc:	An allocator that provides a virtual address to memory
1897  *		for storing the resulting tree
1898  *
1899  * The function scans all the properties of the 'aliases' node and populates
1900  * the global lookup table with the properties.  It returns the
1901  * number of alias properties found, or an error code in case of failure.
1902  */
of_alias_scan(void * (* dt_alloc)(u64 size,u64 align))1903 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1904 {
1905 	struct property *pp;
1906 
1907 	of_aliases = of_find_node_by_path("/aliases");
1908 	of_chosen = of_find_node_by_path("/chosen");
1909 	if (of_chosen == NULL)
1910 		of_chosen = of_find_node_by_path("/chosen@0");
1911 
1912 	if (of_chosen) {
1913 		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1914 		const char *name = NULL;
1915 
1916 		if (of_property_read_string(of_chosen, "stdout-path", &name))
1917 			of_property_read_string(of_chosen, "linux,stdout-path",
1918 						&name);
1919 		if (IS_ENABLED(CONFIG_PPC) && !name)
1920 			of_property_read_string(of_aliases, "stdout", &name);
1921 		if (name)
1922 			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1923 		if (of_stdout)
1924 			of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1925 	}
1926 
1927 	if (!of_aliases)
1928 		return;
1929 
1930 	for_each_property_of_node(of_aliases, pp) {
1931 		const char *start = pp->name;
1932 		const char *end = start + strlen(start);
1933 		struct device_node *np;
1934 		struct alias_prop *ap;
1935 		int id, len;
1936 
1937 		/* Skip those we do not want to proceed */
1938 		if (!strcmp(pp->name, "name") ||
1939 		    !strcmp(pp->name, "phandle") ||
1940 		    !strcmp(pp->name, "linux,phandle"))
1941 			continue;
1942 
1943 		np = of_find_node_by_path(pp->value);
1944 		if (!np)
1945 			continue;
1946 
1947 		/* walk the alias backwards to extract the id and work out
1948 		 * the 'stem' string */
1949 		while (isdigit(*(end-1)) && end > start)
1950 			end--;
1951 		len = end - start;
1952 
1953 		if (kstrtoint(end, 10, &id) < 0)
1954 			continue;
1955 
1956 		/* Allocate an alias_prop with enough space for the stem */
1957 		ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1958 		if (!ap)
1959 			continue;
1960 		memset(ap, 0, sizeof(*ap) + len + 1);
1961 		ap->alias = start;
1962 		of_alias_add(ap, np, id, start, len);
1963 	}
1964 }
1965 
1966 /**
1967  * of_alias_get_id - Get alias id for the given device_node
1968  * @np:		Pointer to the given device_node
1969  * @stem:	Alias stem of the given device_node
1970  *
1971  * The function travels the lookup table to get the alias id for the given
1972  * device_node and alias stem.
1973  *
1974  * Return: The alias id if found.
1975  */
of_alias_get_id(struct device_node * np,const char * stem)1976 int of_alias_get_id(struct device_node *np, const char *stem)
1977 {
1978 	struct alias_prop *app;
1979 	int id = -ENODEV;
1980 
1981 	mutex_lock(&of_mutex);
1982 	list_for_each_entry(app, &aliases_lookup, link) {
1983 		if (strcmp(app->stem, stem) != 0)
1984 			continue;
1985 
1986 		if (np == app->np) {
1987 			id = app->id;
1988 			break;
1989 		}
1990 	}
1991 	mutex_unlock(&of_mutex);
1992 
1993 	return id;
1994 }
1995 EXPORT_SYMBOL_GPL(of_alias_get_id);
1996 
1997 /**
1998  * of_alias_get_highest_id - Get highest alias id for the given stem
1999  * @stem:	Alias stem to be examined
2000  *
2001  * The function travels the lookup table to get the highest alias id for the
2002  * given alias stem.  It returns the alias id if found.
2003  */
of_alias_get_highest_id(const char * stem)2004 int of_alias_get_highest_id(const char *stem)
2005 {
2006 	struct alias_prop *app;
2007 	int id = -ENODEV;
2008 
2009 	mutex_lock(&of_mutex);
2010 	list_for_each_entry(app, &aliases_lookup, link) {
2011 		if (strcmp(app->stem, stem) != 0)
2012 			continue;
2013 
2014 		if (app->id > id)
2015 			id = app->id;
2016 	}
2017 	mutex_unlock(&of_mutex);
2018 
2019 	return id;
2020 }
2021 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2022 
2023 /**
2024  * of_console_check() - Test and setup console for DT setup
2025  * @dn: Pointer to device node
2026  * @name: Name to use for preferred console without index. ex. "ttyS"
2027  * @index: Index to use for preferred console.
2028  *
2029  * Check if the given device node matches the stdout-path property in the
2030  * /chosen node. If it does then register it as the preferred console.
2031  *
2032  * Return: TRUE if console successfully setup. Otherwise return FALSE.
2033  */
of_console_check(struct device_node * dn,char * name,int index)2034 bool of_console_check(struct device_node *dn, char *name, int index)
2035 {
2036 	if (!dn || dn != of_stdout || console_set_on_cmdline)
2037 		return false;
2038 
2039 	/*
2040 	 * XXX: cast `options' to char pointer to suppress complication
2041 	 * warnings: printk, UART and console drivers expect char pointer.
2042 	 */
2043 	return !add_preferred_console(name, index, (char *)of_stdout_options);
2044 }
2045 EXPORT_SYMBOL_GPL(of_console_check);
2046 
2047 /**
2048  * of_find_next_cache_node - Find a node's subsidiary cache
2049  * @np:	node of type "cpu" or "cache"
2050  *
2051  * Return: A node pointer with refcount incremented, use
2052  * of_node_put() on it when done.  Caller should hold a reference
2053  * to np.
2054  */
of_find_next_cache_node(const struct device_node * np)2055 struct device_node *of_find_next_cache_node(const struct device_node *np)
2056 {
2057 	struct device_node *child, *cache_node;
2058 
2059 	cache_node = of_parse_phandle(np, "l2-cache", 0);
2060 	if (!cache_node)
2061 		cache_node = of_parse_phandle(np, "next-level-cache", 0);
2062 
2063 	if (cache_node)
2064 		return cache_node;
2065 
2066 	/* OF on pmac has nodes instead of properties named "l2-cache"
2067 	 * beneath CPU nodes.
2068 	 */
2069 	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2070 		for_each_child_of_node(np, child)
2071 			if (of_node_is_type(child, "cache"))
2072 				return child;
2073 
2074 	return NULL;
2075 }
2076 
2077 /**
2078  * of_find_last_cache_level - Find the level at which the last cache is
2079  * 		present for the given logical cpu
2080  *
2081  * @cpu: cpu number(logical index) for which the last cache level is needed
2082  *
2083  * Return: The level at which the last cache is present. It is exactly
2084  * same as  the total number of cache levels for the given logical cpu.
2085  */
of_find_last_cache_level(unsigned int cpu)2086 int of_find_last_cache_level(unsigned int cpu)
2087 {
2088 	u32 cache_level = 0;
2089 	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2090 
2091 	while (np) {
2092 		of_node_put(prev);
2093 		prev = np;
2094 		np = of_find_next_cache_node(np);
2095 	}
2096 
2097 	of_property_read_u32(prev, "cache-level", &cache_level);
2098 	of_node_put(prev);
2099 
2100 	return cache_level;
2101 }
2102 
2103 /**
2104  * of_map_id - Translate an ID through a downstream mapping.
2105  * @np: root complex device node.
2106  * @id: device ID to map.
2107  * @map_name: property name of the map to use.
2108  * @map_mask_name: optional property name of the mask to use.
2109  * @target: optional pointer to a target device node.
2110  * @id_out: optional pointer to receive the translated ID.
2111  *
2112  * Given a device ID, look up the appropriate implementation-defined
2113  * platform ID and/or the target device which receives transactions on that
2114  * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2115  * @id_out may be NULL if only the other is required. If @target points to
2116  * a non-NULL device node pointer, only entries targeting that node will be
2117  * matched; if it points to a NULL value, it will receive the device node of
2118  * the first matching target phandle, with a reference held.
2119  *
2120  * Return: 0 on success or a standard error code on failure.
2121  */
of_map_id(struct device_node * np,u32 id,const char * map_name,const char * map_mask_name,struct device_node ** target,u32 * id_out)2122 int of_map_id(struct device_node *np, u32 id,
2123 	       const char *map_name, const char *map_mask_name,
2124 	       struct device_node **target, u32 *id_out)
2125 {
2126 	u32 map_mask, masked_id;
2127 	int map_len;
2128 	const __be32 *map = NULL;
2129 
2130 	if (!np || !map_name || (!target && !id_out))
2131 		return -EINVAL;
2132 
2133 	map = of_get_property(np, map_name, &map_len);
2134 	if (!map) {
2135 		if (target)
2136 			return -ENODEV;
2137 		/* Otherwise, no map implies no translation */
2138 		*id_out = id;
2139 		return 0;
2140 	}
2141 
2142 	if (!map_len || map_len % (4 * sizeof(*map))) {
2143 		pr_err("%pOF: Error: Bad %s length: %d\n", np,
2144 			map_name, map_len);
2145 		return -EINVAL;
2146 	}
2147 
2148 	/* The default is to select all bits. */
2149 	map_mask = 0xffffffff;
2150 
2151 	/*
2152 	 * Can be overridden by "{iommu,msi}-map-mask" property.
2153 	 * If of_property_read_u32() fails, the default is used.
2154 	 */
2155 	if (map_mask_name)
2156 		of_property_read_u32(np, map_mask_name, &map_mask);
2157 
2158 	masked_id = map_mask & id;
2159 	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2160 		struct device_node *phandle_node;
2161 		u32 id_base = be32_to_cpup(map + 0);
2162 		u32 phandle = be32_to_cpup(map + 1);
2163 		u32 out_base = be32_to_cpup(map + 2);
2164 		u32 id_len = be32_to_cpup(map + 3);
2165 
2166 		if (id_base & ~map_mask) {
2167 			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2168 				np, map_name, map_name,
2169 				map_mask, id_base);
2170 			return -EFAULT;
2171 		}
2172 
2173 		if (masked_id < id_base || masked_id >= id_base + id_len)
2174 			continue;
2175 
2176 		phandle_node = of_find_node_by_phandle(phandle);
2177 		if (!phandle_node)
2178 			return -ENODEV;
2179 
2180 		if (target) {
2181 			if (*target)
2182 				of_node_put(phandle_node);
2183 			else
2184 				*target = phandle_node;
2185 
2186 			if (*target != phandle_node)
2187 				continue;
2188 		}
2189 
2190 		if (id_out)
2191 			*id_out = masked_id - id_base + out_base;
2192 
2193 		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2194 			np, map_name, map_mask, id_base, out_base,
2195 			id_len, id, masked_id - id_base + out_base);
2196 		return 0;
2197 	}
2198 
2199 	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2200 		id, target && *target ? *target : NULL);
2201 
2202 	/* Bypasses translation */
2203 	if (id_out)
2204 		*id_out = id;
2205 	return 0;
2206 }
2207 EXPORT_SYMBOL_GPL(of_map_id);
2208