1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Derived from arch/i386/kernel/irq.c
4 * Copyright (C) 1992 Linus Torvalds
5 * Adapted from arch/i386 by Gary Thomas
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 * Updated and modified by Cort Dougan <cort@fsmlabs.com>
8 * Copyright (C) 1996-2001 Cort Dougan
9 * Adapted for Power Macintosh by Paul Mackerras
10 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
11 *
12 * This file contains the code used to make IRQ descriptions in the
13 * device tree to actual irq numbers on an interrupt controller
14 * driver.
15 */
16
17 #define pr_fmt(fmt) "OF: " fmt
18
19 #include <linux/device.h>
20 #include <linux/errno.h>
21 #include <linux/list.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/of_irq.h>
25 #include <linux/string.h>
26 #include <linux/slab.h>
27
28 /**
29 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
30 * @dev: Device node of the device whose interrupt is to be mapped
31 * @index: Index of the interrupt to map
32 *
33 * This function is a wrapper that chains of_irq_parse_one() and
34 * irq_create_of_mapping() to make things easier to callers
35 */
36 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
37 {
38 struct of_phandle_args oirq;
39
40 if (of_irq_parse_one(dev, index, &oirq))
41 return 0;
42
43 return irq_create_of_mapping(&oirq);
44 }
45 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
46
47 /**
48 * of_irq_find_parent - Given a device node, find its interrupt parent node
49 * @child: pointer to device node
50 *
51 * Returns a pointer to the interrupt parent node, or NULL if the interrupt
52 * parent could not be determined.
53 */
54 struct device_node *of_irq_find_parent(struct device_node *child)
55 {
56 struct device_node *p;
57 phandle parent;
58
59 if (!of_node_get(child))
60 return NULL;
61
62 do {
63 if (of_property_read_u32(child, "interrupt-parent", &parent)) {
64 p = of_get_parent(child);
65 } else {
66 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
67 p = of_node_get(of_irq_dflt_pic);
68 else
69 p = of_find_node_by_phandle(parent);
70 }
71 of_node_put(child);
72 child = p;
73 } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
74
75 return p;
76 }
77 EXPORT_SYMBOL_GPL(of_irq_find_parent);
78
79 /**
80 * of_irq_parse_raw - Low level interrupt tree parsing
81 * @addr: address specifier (start of "reg" property of the device) in be32 format
82 * @out_irq: structure of_phandle_args updated by this function
83 *
84 * Returns 0 on success and a negative number on error
85 *
86 * This function is a low-level interrupt tree walking function. It
87 * can be used to do a partial walk with synthetized reg and interrupts
88 * properties, for example when resolving PCI interrupts when no device
89 * node exist for the parent. It takes an interrupt specifier structure as
90 * input, walks the tree looking for any interrupt-map properties, translates
91 * the specifier for each map, and then returns the translated map.
92 */
93 int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
94 {
95 struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
96 __be32 initial_match_array[MAX_PHANDLE_ARGS];
97 const __be32 *match_array = initial_match_array;
98 const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
99 u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
100 int imaplen, match, i, rc = -EINVAL;
101
102 #ifdef DEBUG
103 of_print_phandle_args("of_irq_parse_raw: ", out_irq);
104 #endif
105
106 ipar = of_node_get(out_irq->np);
107
108 /* First get the #interrupt-cells property of the current cursor
109 * that tells us how to interpret the passed-in intspec. If there
110 * is none, we are nice and just walk up the tree
111 */
112 do {
113 if (!of_property_read_u32(ipar, "#interrupt-cells", &intsize))
114 break;
115 tnode = ipar;
116 ipar = of_irq_find_parent(ipar);
117 of_node_put(tnode);
118 } while (ipar);
119 if (ipar == NULL) {
120 pr_debug(" -> no parent found !\n");
121 goto fail;
122 }
123
124 pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);
125
126 if (out_irq->args_count != intsize)
127 goto fail;
128
129 /* Look for this #address-cells. We have to implement the old linux
130 * trick of looking for the parent here as some device-trees rely on it
131 */
132 old = of_node_get(ipar);
133 do {
134 tmp = of_get_property(old, "#address-cells", NULL);
135 tnode = of_get_parent(old);
136 of_node_put(old);
137 old = tnode;
138 } while (old && tmp == NULL);
139 of_node_put(old);
140 old = NULL;
141 addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
142
143 pr_debug(" -> addrsize=%d\n", addrsize);
144
145 /* Range check so that the temporary buffer doesn't overflow */
146 if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
147 rc = -EFAULT;
148 goto fail;
149 }
150
151 /* Precalculate the match array - this simplifies match loop */
152 for (i = 0; i < addrsize; i++)
153 initial_match_array[i] = addr ? addr[i] : 0;
154 for (i = 0; i < intsize; i++)
155 initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
156
157 /* Now start the actual "proper" walk of the interrupt tree */
158 while (ipar != NULL) {
159 /* Now check if cursor is an interrupt-controller and if it is
160 * then we are done
161 */
162 if (of_property_read_bool(ipar, "interrupt-controller")) {
163 pr_debug(" -> got it !\n");
164 return 0;
165 }
166
167 /*
168 * interrupt-map parsing does not work without a reg
169 * property when #address-cells != 0
170 */
171 if (addrsize && !addr) {
172 pr_debug(" -> no reg passed in when needed !\n");
173 goto fail;
174 }
175
176 /* Now look for an interrupt-map */
177 imap = of_get_property(ipar, "interrupt-map", &imaplen);
178 /* No interrupt map, check for an interrupt parent */
179 if (imap == NULL) {
180 pr_debug(" -> no map, getting parent\n");
181 newpar = of_irq_find_parent(ipar);
182 goto skiplevel;
183 }
184 imaplen /= sizeof(u32);
185
186 /* Look for a mask */
187 imask = of_get_property(ipar, "interrupt-map-mask", NULL);
188 if (!imask)
189 imask = dummy_imask;
190
191 /* Parse interrupt-map */
192 match = 0;
193 while (imaplen > (addrsize + intsize + 1) && !match) {
194 /* Compare specifiers */
195 match = 1;
196 for (i = 0; i < (addrsize + intsize); i++, imaplen--)
197 match &= !((match_array[i] ^ *imap++) & imask[i]);
198
199 pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
200
201 /* Get the interrupt parent */
202 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
203 newpar = of_node_get(of_irq_dflt_pic);
204 else
205 newpar = of_find_node_by_phandle(be32_to_cpup(imap));
206 imap++;
207 --imaplen;
208
209 /* Check if not found */
210 if (newpar == NULL) {
211 pr_debug(" -> imap parent not found !\n");
212 goto fail;
213 }
214
215 if (!of_device_is_available(newpar))
216 match = 0;
217
218 /* Get #interrupt-cells and #address-cells of new
219 * parent
220 */
221 if (of_property_read_u32(newpar, "#interrupt-cells",
222 &newintsize)) {
223 pr_debug(" -> parent lacks #interrupt-cells!\n");
224 goto fail;
225 }
226 if (of_property_read_u32(newpar, "#address-cells",
227 &newaddrsize))
228 newaddrsize = 0;
229
230 pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
231 newintsize, newaddrsize);
232
233 /* Check for malformed properties */
234 if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)
235 || (imaplen < (newaddrsize + newintsize))) {
236 rc = -EFAULT;
237 goto fail;
238 }
239
240 imap += newaddrsize + newintsize;
241 imaplen -= newaddrsize + newintsize;
242
243 pr_debug(" -> imaplen=%d\n", imaplen);
244 }
245 if (!match)
246 goto fail;
247
248 /*
249 * Successfully parsed an interrrupt-map translation; copy new
250 * interrupt specifier into the out_irq structure
251 */
252 match_array = imap - newaddrsize - newintsize;
253 for (i = 0; i < newintsize; i++)
254 out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
255 out_irq->args_count = intsize = newintsize;
256 addrsize = newaddrsize;
257
258 skiplevel:
259 /* Iterate again with new parent */
260 out_irq->np = newpar;
261 pr_debug(" -> new parent: %pOF\n", newpar);
262 of_node_put(ipar);
263 ipar = newpar;
264 newpar = NULL;
265 }
266 rc = -ENOENT; /* No interrupt-map found */
267
268 fail:
269 of_node_put(ipar);
270 of_node_put(newpar);
271
272 return rc;
273 }
274 EXPORT_SYMBOL_GPL(of_irq_parse_raw);
275
276 /**
277 * of_irq_parse_one - Resolve an interrupt for a device
278 * @device: the device whose interrupt is to be resolved
279 * @index: index of the interrupt to resolve
280 * @out_irq: structure of_phandle_args filled by this function
281 *
282 * This function resolves an interrupt for a node by walking the interrupt tree,
283 * finding which interrupt controller node it is attached to, and returning the
284 * interrupt specifier that can be used to retrieve a Linux IRQ number.
285 */
286 int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
287 {
288 struct device_node *p;
289 const __be32 *addr;
290 u32 intsize;
291 int i, res;
292
293 pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);
294
295 /* OldWorld mac stuff is "special", handle out of line */
296 if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
297 return of_irq_parse_oldworld(device, index, out_irq);
298
299 /* Get the reg property (if any) */
300 addr = of_get_property(device, "reg", NULL);
301
302 /* Try the new-style interrupts-extended first */
303 res = of_parse_phandle_with_args(device, "interrupts-extended",
304 "#interrupt-cells", index, out_irq);
305 if (!res)
306 return of_irq_parse_raw(addr, out_irq);
307
308 /* Look for the interrupt parent. */
309 p = of_irq_find_parent(device);
310 if (p == NULL)
311 return -EINVAL;
312
313 /* Get size of interrupt specifier */
314 if (of_property_read_u32(p, "#interrupt-cells", &intsize)) {
315 res = -EINVAL;
316 goto out;
317 }
318
319 pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);
320
321 /* Copy intspec into irq structure */
322 out_irq->np = p;
323 out_irq->args_count = intsize;
324 for (i = 0; i < intsize; i++) {
325 res = of_property_read_u32_index(device, "interrupts",
326 (index * intsize) + i,
327 out_irq->args + i);
328 if (res)
329 goto out;
330 }
331
332 pr_debug(" intspec=%d\n", *out_irq->args);
333
334
335 /* Check if there are any interrupt-map translations to process */
336 res = of_irq_parse_raw(addr, out_irq);
337 out:
338 of_node_put(p);
339 return res;
340 }
341 EXPORT_SYMBOL_GPL(of_irq_parse_one);
342
343 /**
344 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
345 * @dev: pointer to device tree node
346 * @index: zero-based index of the irq
347 * @r: pointer to resource structure to return result into.
348 */
349 int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
350 {
351 int irq = of_irq_get(dev, index);
352
353 if (irq < 0)
354 return irq;
355
356 /* Only dereference the resource if both the
357 * resource and the irq are valid. */
358 if (r && irq) {
359 const char *name = NULL;
360
361 memset(r, 0, sizeof(*r));
362 /*
363 * Get optional "interrupt-names" property to add a name
364 * to the resource.
365 */
366 of_property_read_string_index(dev, "interrupt-names", index,
367 &name);
368
369 r->start = r->end = irq;
370 r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(irq_get_irq_data(irq));
371 r->name = name ? name : of_node_full_name(dev);
372 }
373
374 return irq;
375 }
376 EXPORT_SYMBOL_GPL(of_irq_to_resource);
377
378 /**
379 * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
380 * @dev: pointer to device tree node
381 * @index: zero-based index of the IRQ
382 *
383 * Returns Linux IRQ number on success, or 0 on the IRQ mapping failure, or
384 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
385 * of any other failure.
386 */
387 int of_irq_get(struct device_node *dev, int index)
388 {
389 int rc;
390 struct of_phandle_args oirq;
391 struct irq_domain *domain;
392
393 rc = of_irq_parse_one(dev, index, &oirq);
394 if (rc)
395 return rc;
396
397 domain = irq_find_host(oirq.np);
398 if (!domain)
399 return -EPROBE_DEFER;
400
401 return irq_create_of_mapping(&oirq);
402 }
403 EXPORT_SYMBOL_GPL(of_irq_get);
404
405 /**
406 * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
407 * @dev: pointer to device tree node
408 * @name: IRQ name
409 *
410 * Returns Linux IRQ number on success, or 0 on the IRQ mapping failure, or
411 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
412 * of any other failure.
413 */
414 int of_irq_get_byname(struct device_node *dev, const char *name)
415 {
416 int index;
417
418 if (unlikely(!name))
419 return -EINVAL;
420
421 index = of_property_match_string(dev, "interrupt-names", name);
422 if (index < 0)
423 return index;
424
425 return of_irq_get(dev, index);
426 }
427 EXPORT_SYMBOL_GPL(of_irq_get_byname);
428
429 /**
430 * of_irq_count - Count the number of IRQs a node uses
431 * @dev: pointer to device tree node
432 */
433 int of_irq_count(struct device_node *dev)
434 {
435 struct of_phandle_args irq;
436 int nr = 0;
437
438 while (of_irq_parse_one(dev, nr, &irq) == 0)
439 nr++;
440
441 return nr;
442 }
443
444 /**
445 * of_irq_to_resource_table - Fill in resource table with node's IRQ info
446 * @dev: pointer to device tree node
447 * @res: array of resources to fill in
448 * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
449 *
450 * Returns the size of the filled in table (up to @nr_irqs).
451 */
452 int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
453 int nr_irqs)
454 {
455 int i;
456
457 for (i = 0; i < nr_irqs; i++, res++)
458 if (of_irq_to_resource(dev, i, res) <= 0)
459 break;
460
461 return i;
462 }
463 EXPORT_SYMBOL_GPL(of_irq_to_resource_table);
464
465 struct of_intc_desc {
466 struct list_head list;
467 of_irq_init_cb_t irq_init_cb;
468 struct device_node *dev;
469 struct device_node *interrupt_parent;
470 };
471
472 /**
473 * of_irq_init - Scan and init matching interrupt controllers in DT
474 * @matches: 0 terminated array of nodes to match and init function to call
475 *
476 * This function scans the device tree for matching interrupt controller nodes,
477 * and calls their initialization functions in order with parents first.
478 */
479 void __init of_irq_init(const struct of_device_id *matches)
480 {
481 const struct of_device_id *match;
482 struct device_node *np, *parent = NULL;
483 struct of_intc_desc *desc, *temp_desc;
484 struct list_head intc_desc_list, intc_parent_list;
485
486 INIT_LIST_HEAD(&intc_desc_list);
487 INIT_LIST_HEAD(&intc_parent_list);
488
489 for_each_matching_node_and_match(np, matches, &match) {
490 if (!of_property_read_bool(np, "interrupt-controller") ||
491 !of_device_is_available(np))
492 continue;
493
494 if (WARN(!match->data, "of_irq_init: no init function for %s\n",
495 match->compatible))
496 continue;
497
498 /*
499 * Here, we allocate and populate an of_intc_desc with the node
500 * pointer, interrupt-parent device_node etc.
501 */
502 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
503 if (!desc) {
504 of_node_put(np);
505 goto err;
506 }
507
508 desc->irq_init_cb = match->data;
509 desc->dev = of_node_get(np);
510 desc->interrupt_parent = of_irq_find_parent(np);
511 if (desc->interrupt_parent == np)
512 desc->interrupt_parent = NULL;
513 list_add_tail(&desc->list, &intc_desc_list);
514 }
515
516 /*
517 * The root irq controller is the one without an interrupt-parent.
518 * That one goes first, followed by the controllers that reference it,
519 * followed by the ones that reference the 2nd level controllers, etc.
520 */
521 while (!list_empty(&intc_desc_list)) {
522 /*
523 * Process all controllers with the current 'parent'.
524 * First pass will be looking for NULL as the parent.
525 * The assumption is that NULL parent means a root controller.
526 */
527 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
528 int ret;
529
530 if (desc->interrupt_parent != parent)
531 continue;
532
533 list_del(&desc->list);
534
535 of_node_set_flag(desc->dev, OF_POPULATED);
536
537 pr_debug("of_irq_init: init %pOF (%p), parent %p\n",
538 desc->dev,
539 desc->dev, desc->interrupt_parent);
540 ret = desc->irq_init_cb(desc->dev,
541 desc->interrupt_parent);
542 if (ret) {
543 of_node_clear_flag(desc->dev, OF_POPULATED);
544 kfree(desc);
545 continue;
546 }
547
548 /*
549 * This one is now set up; add it to the parent list so
550 * its children can get processed in a subsequent pass.
551 */
552 list_add_tail(&desc->list, &intc_parent_list);
553 }
554
555 /* Get the next pending parent that might have children */
556 desc = list_first_entry_or_null(&intc_parent_list,
557 typeof(*desc), list);
558 if (!desc) {
559 pr_err("of_irq_init: children remain, but no parents\n");
560 break;
561 }
562 list_del(&desc->list);
563 parent = desc->dev;
564 kfree(desc);
565 }
566
567 list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
568 list_del(&desc->list);
569 kfree(desc);
570 }
571 err:
572 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
573 list_del(&desc->list);
574 of_node_put(desc->dev);
575 kfree(desc);
576 }
577 }
578
579 static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
580 u32 rid_in)
581 {
582 struct device *parent_dev;
583 u32 rid_out = rid_in;
584
585 /*
586 * Walk up the device parent links looking for one with a
587 * "msi-map" property.
588 */
589 for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
590 if (!of_map_rid(parent_dev->of_node, rid_in, "msi-map",
591 "msi-map-mask", np, &rid_out))
592 break;
593 return rid_out;
594 }
595
596 /**
597 * of_msi_map_rid - Map a MSI requester ID for a device.
598 * @dev: device for which the mapping is to be done.
599 * @msi_np: device node of the expected msi controller.
600 * @rid_in: unmapped MSI requester ID for the device.
601 *
602 * Walk up the device hierarchy looking for devices with a "msi-map"
603 * property. If found, apply the mapping to @rid_in.
604 *
605 * Returns the mapped MSI requester ID.
606 */
607 u32 of_msi_map_rid(struct device *dev, struct device_node *msi_np, u32 rid_in)
608 {
609 return __of_msi_map_rid(dev, &msi_np, rid_in);
610 }
611
612 /**
613 * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
614 * @dev: device for which the mapping is to be done.
615 * @rid: Requester ID for the device.
616 *
617 * Walk up the device hierarchy looking for devices with a "msi-map"
618 * property.
619 *
620 * Returns: the MSI domain for this device (or NULL on failure)
621 */
622 struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 rid)
623 {
624 struct device_node *np = NULL;
625
626 __of_msi_map_rid(dev, &np, rid);
627 return irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);
628 }
629
630 /**
631 * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
632 * @dev: device for which the domain is requested
633 * @np: device node for @dev
634 * @token: bus type for this domain
635 *
636 * Parse the msi-parent property (both the simple and the complex
637 * versions), and returns the corresponding MSI domain.
638 *
639 * Returns: the MSI domain for this device (or NULL on failure).
640 */
641 struct irq_domain *of_msi_get_domain(struct device *dev,
642 struct device_node *np,
643 enum irq_domain_bus_token token)
644 {
645 struct device_node *msi_np;
646 struct irq_domain *d;
647
648 /* Check for a single msi-parent property */
649 msi_np = of_parse_phandle(np, "msi-parent", 0);
650 if (msi_np && !of_property_read_bool(msi_np, "#msi-cells")) {
651 d = irq_find_matching_host(msi_np, token);
652 if (!d)
653 of_node_put(msi_np);
654 return d;
655 }
656
657 if (token == DOMAIN_BUS_PLATFORM_MSI) {
658 /* Check for the complex msi-parent version */
659 struct of_phandle_args args;
660 int index = 0;
661
662 while (!of_parse_phandle_with_args(np, "msi-parent",
663 "#msi-cells",
664 index, &args)) {
665 d = irq_find_matching_host(args.np, token);
666 if (d)
667 return d;
668
669 of_node_put(args.np);
670 index++;
671 }
672 }
673
674 return NULL;
675 }
676
677 /**
678 * of_msi_configure - Set the msi_domain field of a device
679 * @dev: device structure to associate with an MSI irq domain
680 * @np: device node for that device
681 */
682 void of_msi_configure(struct device *dev, struct device_node *np)
683 {
684 dev_set_msi_domain(dev,
685 of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
686 }
687 EXPORT_SYMBOL_GPL(of_msi_configure);