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1 | // SPDX-License-Identifier: GPL-2.0-only | |
2 | /* | |
3 | * linux/kernel/resource.c | |
4 | * | |
5 | * Copyright (C) 1999 Linus Torvalds | |
6 | * Copyright (C) 1999 Martin Mares <mj@ucw.cz> | |
7 | * | |
8 | * Arbitrary resource management. | |
9 | */ | |
10 | ||
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
12 | ||
13 | #include <linux/export.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/ioport.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/spinlock.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/proc_fs.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/seq_file.h> | |
23 | #include <linux/device.h> | |
24 | #include <linux/pfn.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/resource_ext.h> | |
27 | #include <asm/io.h> | |
28 | ||
29 | ||
30 | struct resource ioport_resource = { | |
31 | .name = "PCI IO", | |
32 | .start = 0, | |
33 | .end = IO_SPACE_LIMIT, | |
34 | .flags = IORESOURCE_IO, | |
35 | }; | |
36 | EXPORT_SYMBOL(ioport_resource); | |
37 | ||
38 | struct resource iomem_resource = { | |
39 | .name = "PCI mem", | |
40 | .start = 0, | |
41 | .end = -1, | |
42 | .flags = IORESOURCE_MEM, | |
43 | }; | |
44 | EXPORT_SYMBOL(iomem_resource); | |
45 | ||
46 | /* constraints to be met while allocating resources */ | |
47 | struct resource_constraint { | |
48 | resource_size_t min, max, align; | |
49 | resource_size_t (*alignf)(void *, const struct resource *, | |
50 | resource_size_t, resource_size_t); | |
51 | void *alignf_data; | |
52 | }; | |
53 | ||
54 | static DEFINE_RWLOCK(resource_lock); | |
55 | ||
56 | /* | |
57 | * For memory hotplug, there is no way to free resource entries allocated | |
58 | * by boot mem after the system is up. So for reusing the resource entry | |
59 | * we need to remember the resource. | |
60 | */ | |
61 | static struct resource *bootmem_resource_free; | |
62 | static DEFINE_SPINLOCK(bootmem_resource_lock); | |
63 | ||
64 | static struct resource *next_resource(struct resource *p, bool sibling_only) | |
65 | { | |
66 | /* Caller wants to traverse through siblings only */ | |
67 | if (sibling_only) | |
68 | return p->sibling; | |
69 | ||
70 | if (p->child) | |
71 | return p->child; | |
72 | while (!p->sibling && p->parent) | |
73 | p = p->parent; | |
74 | return p->sibling; | |
75 | } | |
76 | ||
77 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | |
78 | { | |
79 | struct resource *p = v; | |
80 | (*pos)++; | |
81 | return (void *)next_resource(p, false); | |
82 | } | |
83 | ||
84 | #ifdef CONFIG_PROC_FS | |
85 | ||
86 | enum { MAX_IORES_LEVEL = 5 }; | |
87 | ||
88 | static void *r_start(struct seq_file *m, loff_t *pos) | |
89 | __acquires(resource_lock) | |
90 | { | |
91 | struct resource *p = PDE_DATA(file_inode(m->file)); | |
92 | loff_t l = 0; | |
93 | read_lock(&resource_lock); | |
94 | for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) | |
95 | ; | |
96 | return p; | |
97 | } | |
98 | ||
99 | static void r_stop(struct seq_file *m, void *v) | |
100 | __releases(resource_lock) | |
101 | { | |
102 | read_unlock(&resource_lock); | |
103 | } | |
104 | ||
105 | static int r_show(struct seq_file *m, void *v) | |
106 | { | |
107 | struct resource *root = PDE_DATA(file_inode(m->file)); | |
108 | struct resource *r = v, *p; | |
109 | unsigned long long start, end; | |
110 | int width = root->end < 0x10000 ? 4 : 8; | |
111 | int depth; | |
112 | ||
113 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) | |
114 | if (p->parent == root) | |
115 | break; | |
116 | ||
117 | if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) { | |
118 | start = r->start; | |
119 | end = r->end; | |
120 | } else { | |
121 | start = end = 0; | |
122 | } | |
123 | ||
124 | seq_printf(m, "%*s%0*llx-%0*llx : %s\n", | |
125 | depth * 2, "", | |
126 | width, start, | |
127 | width, end, | |
128 | r->name ? r->name : "<BAD>"); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | static const struct seq_operations resource_op = { | |
133 | .start = r_start, | |
134 | .next = r_next, | |
135 | .stop = r_stop, | |
136 | .show = r_show, | |
137 | }; | |
138 | ||
139 | static int __init ioresources_init(void) | |
140 | { | |
141 | proc_create_seq_data("ioports", 0, NULL, &resource_op, | |
142 | &ioport_resource); | |
143 | proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource); | |
144 | return 0; | |
145 | } | |
146 | __initcall(ioresources_init); | |
147 | ||
148 | #endif /* CONFIG_PROC_FS */ | |
149 | ||
150 | static void free_resource(struct resource *res) | |
151 | { | |
152 | if (!res) | |
153 | return; | |
154 | ||
155 | if (!PageSlab(virt_to_head_page(res))) { | |
156 | spin_lock(&bootmem_resource_lock); | |
157 | res->sibling = bootmem_resource_free; | |
158 | bootmem_resource_free = res; | |
159 | spin_unlock(&bootmem_resource_lock); | |
160 | } else { | |
161 | kfree(res); | |
162 | } | |
163 | } | |
164 | ||
165 | static struct resource *alloc_resource(gfp_t flags) | |
166 | { | |
167 | struct resource *res = NULL; | |
168 | ||
169 | spin_lock(&bootmem_resource_lock); | |
170 | if (bootmem_resource_free) { | |
171 | res = bootmem_resource_free; | |
172 | bootmem_resource_free = res->sibling; | |
173 | } | |
174 | spin_unlock(&bootmem_resource_lock); | |
175 | ||
176 | if (res) | |
177 | memset(res, 0, sizeof(struct resource)); | |
178 | else | |
179 | res = kzalloc(sizeof(struct resource), flags); | |
180 | ||
181 | return res; | |
182 | } | |
183 | ||
184 | /* Return the conflict entry if you can't request it */ | |
185 | static struct resource * __request_resource(struct resource *root, struct resource *new) | |
186 | { | |
187 | resource_size_t start = new->start; | |
188 | resource_size_t end = new->end; | |
189 | struct resource *tmp, **p; | |
190 | ||
191 | if (end < start) | |
192 | return root; | |
193 | if (start < root->start) | |
194 | return root; | |
195 | if (end > root->end) | |
196 | return root; | |
197 | p = &root->child; | |
198 | for (;;) { | |
199 | tmp = *p; | |
200 | if (!tmp || tmp->start > end) { | |
201 | new->sibling = tmp; | |
202 | *p = new; | |
203 | new->parent = root; | |
204 | return NULL; | |
205 | } | |
206 | p = &tmp->sibling; | |
207 | if (tmp->end < start) | |
208 | continue; | |
209 | return tmp; | |
210 | } | |
211 | } | |
212 | ||
213 | static int __release_resource(struct resource *old, bool release_child) | |
214 | { | |
215 | struct resource *tmp, **p, *chd; | |
216 | ||
217 | p = &old->parent->child; | |
218 | for (;;) { | |
219 | tmp = *p; | |
220 | if (!tmp) | |
221 | break; | |
222 | if (tmp == old) { | |
223 | if (release_child || !(tmp->child)) { | |
224 | *p = tmp->sibling; | |
225 | } else { | |
226 | for (chd = tmp->child;; chd = chd->sibling) { | |
227 | chd->parent = tmp->parent; | |
228 | if (!(chd->sibling)) | |
229 | break; | |
230 | } | |
231 | *p = tmp->child; | |
232 | chd->sibling = tmp->sibling; | |
233 | } | |
234 | old->parent = NULL; | |
235 | return 0; | |
236 | } | |
237 | p = &tmp->sibling; | |
238 | } | |
239 | return -EINVAL; | |
240 | } | |
241 | ||
242 | static void __release_child_resources(struct resource *r) | |
243 | { | |
244 | struct resource *tmp, *p; | |
245 | resource_size_t size; | |
246 | ||
247 | p = r->child; | |
248 | r->child = NULL; | |
249 | while (p) { | |
250 | tmp = p; | |
251 | p = p->sibling; | |
252 | ||
253 | tmp->parent = NULL; | |
254 | tmp->sibling = NULL; | |
255 | __release_child_resources(tmp); | |
256 | ||
257 | printk(KERN_DEBUG "release child resource %pR\n", tmp); | |
258 | /* need to restore size, and keep flags */ | |
259 | size = resource_size(tmp); | |
260 | tmp->start = 0; | |
261 | tmp->end = size - 1; | |
262 | } | |
263 | } | |
264 | ||
265 | void release_child_resources(struct resource *r) | |
266 | { | |
267 | write_lock(&resource_lock); | |
268 | __release_child_resources(r); | |
269 | write_unlock(&resource_lock); | |
270 | } | |
271 | ||
272 | /** | |
273 | * request_resource_conflict - request and reserve an I/O or memory resource | |
274 | * @root: root resource descriptor | |
275 | * @new: resource descriptor desired by caller | |
276 | * | |
277 | * Returns 0 for success, conflict resource on error. | |
278 | */ | |
279 | struct resource *request_resource_conflict(struct resource *root, struct resource *new) | |
280 | { | |
281 | struct resource *conflict; | |
282 | ||
283 | write_lock(&resource_lock); | |
284 | conflict = __request_resource(root, new); | |
285 | write_unlock(&resource_lock); | |
286 | return conflict; | |
287 | } | |
288 | ||
289 | /** | |
290 | * request_resource - request and reserve an I/O or memory resource | |
291 | * @root: root resource descriptor | |
292 | * @new: resource descriptor desired by caller | |
293 | * | |
294 | * Returns 0 for success, negative error code on error. | |
295 | */ | |
296 | int request_resource(struct resource *root, struct resource *new) | |
297 | { | |
298 | struct resource *conflict; | |
299 | ||
300 | conflict = request_resource_conflict(root, new); | |
301 | return conflict ? -EBUSY : 0; | |
302 | } | |
303 | ||
304 | EXPORT_SYMBOL(request_resource); | |
305 | ||
306 | /** | |
307 | * release_resource - release a previously reserved resource | |
308 | * @old: resource pointer | |
309 | */ | |
310 | int release_resource(struct resource *old) | |
311 | { | |
312 | int retval; | |
313 | ||
314 | write_lock(&resource_lock); | |
315 | retval = __release_resource(old, true); | |
316 | write_unlock(&resource_lock); | |
317 | return retval; | |
318 | } | |
319 | ||
320 | EXPORT_SYMBOL(release_resource); | |
321 | ||
322 | /** | |
323 | * Finds the lowest iomem resource that covers part of [@start..@end]. The | |
324 | * caller must specify @start, @end, @flags, and @desc (which may be | |
325 | * IORES_DESC_NONE). | |
326 | * | |
327 | * If a resource is found, returns 0 and @*res is overwritten with the part | |
328 | * of the resource that's within [@start..@end]; if none is found, returns | |
329 | * -ENODEV. Returns -EINVAL for invalid parameters. | |
330 | * | |
331 | * This function walks the whole tree and not just first level children | |
332 | * unless @first_lvl is true. | |
333 | * | |
334 | * @start: start address of the resource searched for | |
335 | * @end: end address of same resource | |
336 | * @flags: flags which the resource must have | |
337 | * @desc: descriptor the resource must have | |
338 | * @first_lvl: walk only the first level children, if set | |
339 | * @res: return ptr, if resource found | |
340 | */ | |
341 | static int find_next_iomem_res(resource_size_t start, resource_size_t end, | |
342 | unsigned long flags, unsigned long desc, | |
343 | bool first_lvl, struct resource *res) | |
344 | { | |
345 | bool siblings_only = true; | |
346 | struct resource *p; | |
347 | ||
348 | if (!res) | |
349 | return -EINVAL; | |
350 | ||
351 | if (start >= end) | |
352 | return -EINVAL; | |
353 | ||
354 | read_lock(&resource_lock); | |
355 | ||
356 | for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) { | |
357 | /* If we passed the resource we are looking for, stop */ | |
358 | if (p->start > end) { | |
359 | p = NULL; | |
360 | break; | |
361 | } | |
362 | ||
363 | /* Skip until we find a range that matches what we look for */ | |
364 | if (p->end < start) | |
365 | continue; | |
366 | ||
367 | /* | |
368 | * Now that we found a range that matches what we look for, | |
369 | * check the flags and the descriptor. If we were not asked to | |
370 | * use only the first level, start looking at children as well. | |
371 | */ | |
372 | siblings_only = first_lvl; | |
373 | ||
374 | if ((p->flags & flags) != flags) | |
375 | continue; | |
376 | if ((desc != IORES_DESC_NONE) && (desc != p->desc)) | |
377 | continue; | |
378 | ||
379 | /* Found a match, break */ | |
380 | break; | |
381 | } | |
382 | ||
383 | if (p) { | |
384 | /* copy data */ | |
385 | res->start = max(start, p->start); | |
386 | res->end = min(end, p->end); | |
387 | res->flags = p->flags; | |
388 | res->desc = p->desc; | |
389 | } | |
390 | ||
391 | read_unlock(&resource_lock); | |
392 | return p ? 0 : -ENODEV; | |
393 | } | |
394 | ||
395 | static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, | |
396 | unsigned long flags, unsigned long desc, | |
397 | bool first_lvl, void *arg, | |
398 | int (*func)(struct resource *, void *)) | |
399 | { | |
400 | struct resource res; | |
401 | int ret = -EINVAL; | |
402 | ||
403 | while (start < end && | |
404 | !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) { | |
405 | ret = (*func)(&res, arg); | |
406 | if (ret) | |
407 | break; | |
408 | ||
409 | start = res.end + 1; | |
410 | } | |
411 | ||
412 | return ret; | |
413 | } | |
414 | ||
415 | /** | |
416 | * Walks through iomem resources and calls func() with matching resource | |
417 | * ranges. This walks through whole tree and not just first level children. | |
418 | * All the memory ranges which overlap start,end and also match flags and | |
419 | * desc are valid candidates. | |
420 | * | |
421 | * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check. | |
422 | * @flags: I/O resource flags | |
423 | * @start: start addr | |
424 | * @end: end addr | |
425 | * @arg: function argument for the callback @func | |
426 | * @func: callback function that is called for each qualifying resource area | |
427 | * | |
428 | * NOTE: For a new descriptor search, define a new IORES_DESC in | |
429 | * <linux/ioport.h> and set it in 'desc' of a target resource entry. | |
430 | */ | |
431 | int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, | |
432 | u64 end, void *arg, int (*func)(struct resource *, void *)) | |
433 | { | |
434 | return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func); | |
435 | } | |
436 | EXPORT_SYMBOL_GPL(walk_iomem_res_desc); | |
437 | ||
438 | /* | |
439 | * This function calls the @func callback against all memory ranges of type | |
440 | * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. | |
441 | * Now, this function is only for System RAM, it deals with full ranges and | |
442 | * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate | |
443 | * ranges. | |
444 | */ | |
445 | int walk_system_ram_res(u64 start, u64 end, void *arg, | |
446 | int (*func)(struct resource *, void *)) | |
447 | { | |
448 | unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; | |
449 | ||
450 | return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true, | |
451 | arg, func); | |
452 | } | |
453 | ||
454 | /* | |
455 | * This function calls the @func callback against all memory ranges, which | |
456 | * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. | |
457 | */ | |
458 | int walk_mem_res(u64 start, u64 end, void *arg, | |
459 | int (*func)(struct resource *, void *)) | |
460 | { | |
461 | unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; | |
462 | ||
463 | return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true, | |
464 | arg, func); | |
465 | } | |
466 | ||
467 | /* | |
468 | * This function calls the @func callback against all memory ranges of type | |
469 | * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. | |
470 | * It is to be used only for System RAM. | |
471 | * | |
472 | * This will find System RAM ranges that are children of top-level resources | |
473 | * in addition to top-level System RAM resources. | |
474 | */ | |
475 | int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, | |
476 | void *arg, int (*func)(unsigned long, unsigned long, void *)) | |
477 | { | |
478 | resource_size_t start, end; | |
479 | unsigned long flags; | |
480 | struct resource res; | |
481 | unsigned long pfn, end_pfn; | |
482 | int ret = -EINVAL; | |
483 | ||
484 | start = (u64) start_pfn << PAGE_SHIFT; | |
485 | end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; | |
486 | flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; | |
487 | while (start < end && | |
488 | !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, | |
489 | false, &res)) { | |
490 | pfn = PFN_UP(res.start); | |
491 | end_pfn = PFN_DOWN(res.end + 1); | |
492 | if (end_pfn > pfn) | |
493 | ret = (*func)(pfn, end_pfn - pfn, arg); | |
494 | if (ret) | |
495 | break; | |
496 | start = res.end + 1; | |
497 | } | |
498 | return ret; | |
499 | } | |
500 | ||
501 | static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) | |
502 | { | |
503 | return 1; | |
504 | } | |
505 | ||
506 | /* | |
507 | * This generic page_is_ram() returns true if specified address is | |
508 | * registered as System RAM in iomem_resource list. | |
509 | */ | |
510 | int __weak page_is_ram(unsigned long pfn) | |
511 | { | |
512 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; | |
513 | } | |
514 | EXPORT_SYMBOL_GPL(page_is_ram); | |
515 | ||
516 | /** | |
517 | * region_intersects() - determine intersection of region with known resources | |
518 | * @start: region start address | |
519 | * @size: size of region | |
520 | * @flags: flags of resource (in iomem_resource) | |
521 | * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE | |
522 | * | |
523 | * Check if the specified region partially overlaps or fully eclipses a | |
524 | * resource identified by @flags and @desc (optional with IORES_DESC_NONE). | |
525 | * Return REGION_DISJOINT if the region does not overlap @flags/@desc, | |
526 | * return REGION_MIXED if the region overlaps @flags/@desc and another | |
527 | * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc | |
528 | * and no other defined resource. Note that REGION_INTERSECTS is also | |
529 | * returned in the case when the specified region overlaps RAM and undefined | |
530 | * memory holes. | |
531 | * | |
532 | * region_intersect() is used by memory remapping functions to ensure | |
533 | * the user is not remapping RAM and is a vast speed up over walking | |
534 | * through the resource table page by page. | |
535 | */ | |
536 | int region_intersects(resource_size_t start, size_t size, unsigned long flags, | |
537 | unsigned long desc) | |
538 | { | |
539 | struct resource res; | |
540 | int type = 0; int other = 0; | |
541 | struct resource *p; | |
542 | ||
543 | res.start = start; | |
544 | res.end = start + size - 1; | |
545 | ||
546 | read_lock(&resource_lock); | |
547 | for (p = iomem_resource.child; p ; p = p->sibling) { | |
548 | bool is_type = (((p->flags & flags) == flags) && | |
549 | ((desc == IORES_DESC_NONE) || | |
550 | (desc == p->desc))); | |
551 | ||
552 | if (resource_overlaps(p, &res)) | |
553 | is_type ? type++ : other++; | |
554 | } | |
555 | read_unlock(&resource_lock); | |
556 | ||
557 | if (other == 0) | |
558 | return type ? REGION_INTERSECTS : REGION_DISJOINT; | |
559 | ||
560 | if (type) | |
561 | return REGION_MIXED; | |
562 | ||
563 | return REGION_DISJOINT; | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(region_intersects); | |
566 | ||
567 | void __weak arch_remove_reservations(struct resource *avail) | |
568 | { | |
569 | } | |
570 | ||
571 | static resource_size_t simple_align_resource(void *data, | |
572 | const struct resource *avail, | |
573 | resource_size_t size, | |
574 | resource_size_t align) | |
575 | { | |
576 | return avail->start; | |
577 | } | |
578 | ||
579 | static void resource_clip(struct resource *res, resource_size_t min, | |
580 | resource_size_t max) | |
581 | { | |
582 | if (res->start < min) | |
583 | res->start = min; | |
584 | if (res->end > max) | |
585 | res->end = max; | |
586 | } | |
587 | ||
588 | /* | |
589 | * Find empty slot in the resource tree with the given range and | |
590 | * alignment constraints | |
591 | */ | |
592 | static int __find_resource(struct resource *root, struct resource *old, | |
593 | struct resource *new, | |
594 | resource_size_t size, | |
595 | struct resource_constraint *constraint) | |
596 | { | |
597 | struct resource *this = root->child; | |
598 | struct resource tmp = *new, avail, alloc; | |
599 | ||
600 | tmp.start = root->start; | |
601 | /* | |
602 | * Skip past an allocated resource that starts at 0, since the assignment | |
603 | * of this->start - 1 to tmp->end below would cause an underflow. | |
604 | */ | |
605 | if (this && this->start == root->start) { | |
606 | tmp.start = (this == old) ? old->start : this->end + 1; | |
607 | this = this->sibling; | |
608 | } | |
609 | for(;;) { | |
610 | if (this) | |
611 | tmp.end = (this == old) ? this->end : this->start - 1; | |
612 | else | |
613 | tmp.end = root->end; | |
614 | ||
615 | if (tmp.end < tmp.start) | |
616 | goto next; | |
617 | ||
618 | resource_clip(&tmp, constraint->min, constraint->max); | |
619 | arch_remove_reservations(&tmp); | |
620 | ||
621 | /* Check for overflow after ALIGN() */ | |
622 | avail.start = ALIGN(tmp.start, constraint->align); | |
623 | avail.end = tmp.end; | |
624 | avail.flags = new->flags & ~IORESOURCE_UNSET; | |
625 | if (avail.start >= tmp.start) { | |
626 | alloc.flags = avail.flags; | |
627 | alloc.start = constraint->alignf(constraint->alignf_data, &avail, | |
628 | size, constraint->align); | |
629 | alloc.end = alloc.start + size - 1; | |
630 | if (alloc.start <= alloc.end && | |
631 | resource_contains(&avail, &alloc)) { | |
632 | new->start = alloc.start; | |
633 | new->end = alloc.end; | |
634 | return 0; | |
635 | } | |
636 | } | |
637 | ||
638 | next: if (!this || this->end == root->end) | |
639 | break; | |
640 | ||
641 | if (this != old) | |
642 | tmp.start = this->end + 1; | |
643 | this = this->sibling; | |
644 | } | |
645 | return -EBUSY; | |
646 | } | |
647 | ||
648 | /* | |
649 | * Find empty slot in the resource tree given range and alignment. | |
650 | */ | |
651 | static int find_resource(struct resource *root, struct resource *new, | |
652 | resource_size_t size, | |
653 | struct resource_constraint *constraint) | |
654 | { | |
655 | return __find_resource(root, NULL, new, size, constraint); | |
656 | } | |
657 | ||
658 | /** | |
659 | * reallocate_resource - allocate a slot in the resource tree given range & alignment. | |
660 | * The resource will be relocated if the new size cannot be reallocated in the | |
661 | * current location. | |
662 | * | |
663 | * @root: root resource descriptor | |
664 | * @old: resource descriptor desired by caller | |
665 | * @newsize: new size of the resource descriptor | |
666 | * @constraint: the size and alignment constraints to be met. | |
667 | */ | |
668 | static int reallocate_resource(struct resource *root, struct resource *old, | |
669 | resource_size_t newsize, | |
670 | struct resource_constraint *constraint) | |
671 | { | |
672 | int err=0; | |
673 | struct resource new = *old; | |
674 | struct resource *conflict; | |
675 | ||
676 | write_lock(&resource_lock); | |
677 | ||
678 | if ((err = __find_resource(root, old, &new, newsize, constraint))) | |
679 | goto out; | |
680 | ||
681 | if (resource_contains(&new, old)) { | |
682 | old->start = new.start; | |
683 | old->end = new.end; | |
684 | goto out; | |
685 | } | |
686 | ||
687 | if (old->child) { | |
688 | err = -EBUSY; | |
689 | goto out; | |
690 | } | |
691 | ||
692 | if (resource_contains(old, &new)) { | |
693 | old->start = new.start; | |
694 | old->end = new.end; | |
695 | } else { | |
696 | __release_resource(old, true); | |
697 | *old = new; | |
698 | conflict = __request_resource(root, old); | |
699 | BUG_ON(conflict); | |
700 | } | |
701 | out: | |
702 | write_unlock(&resource_lock); | |
703 | return err; | |
704 | } | |
705 | ||
706 | ||
707 | /** | |
708 | * allocate_resource - allocate empty slot in the resource tree given range & alignment. | |
709 | * The resource will be reallocated with a new size if it was already allocated | |
710 | * @root: root resource descriptor | |
711 | * @new: resource descriptor desired by caller | |
712 | * @size: requested resource region size | |
713 | * @min: minimum boundary to allocate | |
714 | * @max: maximum boundary to allocate | |
715 | * @align: alignment requested, in bytes | |
716 | * @alignf: alignment function, optional, called if not NULL | |
717 | * @alignf_data: arbitrary data to pass to the @alignf function | |
718 | */ | |
719 | int allocate_resource(struct resource *root, struct resource *new, | |
720 | resource_size_t size, resource_size_t min, | |
721 | resource_size_t max, resource_size_t align, | |
722 | resource_size_t (*alignf)(void *, | |
723 | const struct resource *, | |
724 | resource_size_t, | |
725 | resource_size_t), | |
726 | void *alignf_data) | |
727 | { | |
728 | int err; | |
729 | struct resource_constraint constraint; | |
730 | ||
731 | if (!alignf) | |
732 | alignf = simple_align_resource; | |
733 | ||
734 | constraint.min = min; | |
735 | constraint.max = max; | |
736 | constraint.align = align; | |
737 | constraint.alignf = alignf; | |
738 | constraint.alignf_data = alignf_data; | |
739 | ||
740 | if ( new->parent ) { | |
741 | /* resource is already allocated, try reallocating with | |
742 | the new constraints */ | |
743 | return reallocate_resource(root, new, size, &constraint); | |
744 | } | |
745 | ||
746 | write_lock(&resource_lock); | |
747 | err = find_resource(root, new, size, &constraint); | |
748 | if (err >= 0 && __request_resource(root, new)) | |
749 | err = -EBUSY; | |
750 | write_unlock(&resource_lock); | |
751 | return err; | |
752 | } | |
753 | ||
754 | EXPORT_SYMBOL(allocate_resource); | |
755 | ||
756 | /** | |
757 | * lookup_resource - find an existing resource by a resource start address | |
758 | * @root: root resource descriptor | |
759 | * @start: resource start address | |
760 | * | |
761 | * Returns a pointer to the resource if found, NULL otherwise | |
762 | */ | |
763 | struct resource *lookup_resource(struct resource *root, resource_size_t start) | |
764 | { | |
765 | struct resource *res; | |
766 | ||
767 | read_lock(&resource_lock); | |
768 | for (res = root->child; res; res = res->sibling) { | |
769 | if (res->start == start) | |
770 | break; | |
771 | } | |
772 | read_unlock(&resource_lock); | |
773 | ||
774 | return res; | |
775 | } | |
776 | ||
777 | /* | |
778 | * Insert a resource into the resource tree. If successful, return NULL, | |
779 | * otherwise return the conflicting resource (compare to __request_resource()) | |
780 | */ | |
781 | static struct resource * __insert_resource(struct resource *parent, struct resource *new) | |
782 | { | |
783 | struct resource *first, *next; | |
784 | ||
785 | for (;; parent = first) { | |
786 | first = __request_resource(parent, new); | |
787 | if (!first) | |
788 | return first; | |
789 | ||
790 | if (first == parent) | |
791 | return first; | |
792 | if (WARN_ON(first == new)) /* duplicated insertion */ | |
793 | return first; | |
794 | ||
795 | if ((first->start > new->start) || (first->end < new->end)) | |
796 | break; | |
797 | if ((first->start == new->start) && (first->end == new->end)) | |
798 | break; | |
799 | } | |
800 | ||
801 | for (next = first; ; next = next->sibling) { | |
802 | /* Partial overlap? Bad, and unfixable */ | |
803 | if (next->start < new->start || next->end > new->end) | |
804 | return next; | |
805 | if (!next->sibling) | |
806 | break; | |
807 | if (next->sibling->start > new->end) | |
808 | break; | |
809 | } | |
810 | ||
811 | new->parent = parent; | |
812 | new->sibling = next->sibling; | |
813 | new->child = first; | |
814 | ||
815 | next->sibling = NULL; | |
816 | for (next = first; next; next = next->sibling) | |
817 | next->parent = new; | |
818 | ||
819 | if (parent->child == first) { | |
820 | parent->child = new; | |
821 | } else { | |
822 | next = parent->child; | |
823 | while (next->sibling != first) | |
824 | next = next->sibling; | |
825 | next->sibling = new; | |
826 | } | |
827 | return NULL; | |
828 | } | |
829 | ||
830 | /** | |
831 | * insert_resource_conflict - Inserts resource in the resource tree | |
832 | * @parent: parent of the new resource | |
833 | * @new: new resource to insert | |
834 | * | |
835 | * Returns 0 on success, conflict resource if the resource can't be inserted. | |
836 | * | |
837 | * This function is equivalent to request_resource_conflict when no conflict | |
838 | * happens. If a conflict happens, and the conflicting resources | |
839 | * entirely fit within the range of the new resource, then the new | |
840 | * resource is inserted and the conflicting resources become children of | |
841 | * the new resource. | |
842 | * | |
843 | * This function is intended for producers of resources, such as FW modules | |
844 | * and bus drivers. | |
845 | */ | |
846 | struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) | |
847 | { | |
848 | struct resource *conflict; | |
849 | ||
850 | write_lock(&resource_lock); | |
851 | conflict = __insert_resource(parent, new); | |
852 | write_unlock(&resource_lock); | |
853 | return conflict; | |
854 | } | |
855 | ||
856 | /** | |
857 | * insert_resource - Inserts a resource in the resource tree | |
858 | * @parent: parent of the new resource | |
859 | * @new: new resource to insert | |
860 | * | |
861 | * Returns 0 on success, -EBUSY if the resource can't be inserted. | |
862 | * | |
863 | * This function is intended for producers of resources, such as FW modules | |
864 | * and bus drivers. | |
865 | */ | |
866 | int insert_resource(struct resource *parent, struct resource *new) | |
867 | { | |
868 | struct resource *conflict; | |
869 | ||
870 | conflict = insert_resource_conflict(parent, new); | |
871 | return conflict ? -EBUSY : 0; | |
872 | } | |
873 | EXPORT_SYMBOL_GPL(insert_resource); | |
874 | ||
875 | /** | |
876 | * insert_resource_expand_to_fit - Insert a resource into the resource tree | |
877 | * @root: root resource descriptor | |
878 | * @new: new resource to insert | |
879 | * | |
880 | * Insert a resource into the resource tree, possibly expanding it in order | |
881 | * to make it encompass any conflicting resources. | |
882 | */ | |
883 | void insert_resource_expand_to_fit(struct resource *root, struct resource *new) | |
884 | { | |
885 | if (new->parent) | |
886 | return; | |
887 | ||
888 | write_lock(&resource_lock); | |
889 | for (;;) { | |
890 | struct resource *conflict; | |
891 | ||
892 | conflict = __insert_resource(root, new); | |
893 | if (!conflict) | |
894 | break; | |
895 | if (conflict == root) | |
896 | break; | |
897 | ||
898 | /* Ok, expand resource to cover the conflict, then try again .. */ | |
899 | if (conflict->start < new->start) | |
900 | new->start = conflict->start; | |
901 | if (conflict->end > new->end) | |
902 | new->end = conflict->end; | |
903 | ||
904 | printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); | |
905 | } | |
906 | write_unlock(&resource_lock); | |
907 | } | |
908 | ||
909 | /** | |
910 | * remove_resource - Remove a resource in the resource tree | |
911 | * @old: resource to remove | |
912 | * | |
913 | * Returns 0 on success, -EINVAL if the resource is not valid. | |
914 | * | |
915 | * This function removes a resource previously inserted by insert_resource() | |
916 | * or insert_resource_conflict(), and moves the children (if any) up to | |
917 | * where they were before. insert_resource() and insert_resource_conflict() | |
918 | * insert a new resource, and move any conflicting resources down to the | |
919 | * children of the new resource. | |
920 | * | |
921 | * insert_resource(), insert_resource_conflict() and remove_resource() are | |
922 | * intended for producers of resources, such as FW modules and bus drivers. | |
923 | */ | |
924 | int remove_resource(struct resource *old) | |
925 | { | |
926 | int retval; | |
927 | ||
928 | write_lock(&resource_lock); | |
929 | retval = __release_resource(old, false); | |
930 | write_unlock(&resource_lock); | |
931 | return retval; | |
932 | } | |
933 | EXPORT_SYMBOL_GPL(remove_resource); | |
934 | ||
935 | static int __adjust_resource(struct resource *res, resource_size_t start, | |
936 | resource_size_t size) | |
937 | { | |
938 | struct resource *tmp, *parent = res->parent; | |
939 | resource_size_t end = start + size - 1; | |
940 | int result = -EBUSY; | |
941 | ||
942 | if (!parent) | |
943 | goto skip; | |
944 | ||
945 | if ((start < parent->start) || (end > parent->end)) | |
946 | goto out; | |
947 | ||
948 | if (res->sibling && (res->sibling->start <= end)) | |
949 | goto out; | |
950 | ||
951 | tmp = parent->child; | |
952 | if (tmp != res) { | |
953 | while (tmp->sibling != res) | |
954 | tmp = tmp->sibling; | |
955 | if (start <= tmp->end) | |
956 | goto out; | |
957 | } | |
958 | ||
959 | skip: | |
960 | for (tmp = res->child; tmp; tmp = tmp->sibling) | |
961 | if ((tmp->start < start) || (tmp->end > end)) | |
962 | goto out; | |
963 | ||
964 | res->start = start; | |
965 | res->end = end; | |
966 | result = 0; | |
967 | ||
968 | out: | |
969 | return result; | |
970 | } | |
971 | ||
972 | /** | |
973 | * adjust_resource - modify a resource's start and size | |
974 | * @res: resource to modify | |
975 | * @start: new start value | |
976 | * @size: new size | |
977 | * | |
978 | * Given an existing resource, change its start and size to match the | |
979 | * arguments. Returns 0 on success, -EBUSY if it can't fit. | |
980 | * Existing children of the resource are assumed to be immutable. | |
981 | */ | |
982 | int adjust_resource(struct resource *res, resource_size_t start, | |
983 | resource_size_t size) | |
984 | { | |
985 | int result; | |
986 | ||
987 | write_lock(&resource_lock); | |
988 | result = __adjust_resource(res, start, size); | |
989 | write_unlock(&resource_lock); | |
990 | return result; | |
991 | } | |
992 | EXPORT_SYMBOL(adjust_resource); | |
993 | ||
994 | static void __init | |
995 | __reserve_region_with_split(struct resource *root, resource_size_t start, | |
996 | resource_size_t end, const char *name) | |
997 | { | |
998 | struct resource *parent = root; | |
999 | struct resource *conflict; | |
1000 | struct resource *res = alloc_resource(GFP_ATOMIC); | |
1001 | struct resource *next_res = NULL; | |
1002 | int type = resource_type(root); | |
1003 | ||
1004 | if (!res) | |
1005 | return; | |
1006 | ||
1007 | res->name = name; | |
1008 | res->start = start; | |
1009 | res->end = end; | |
1010 | res->flags = type | IORESOURCE_BUSY; | |
1011 | res->desc = IORES_DESC_NONE; | |
1012 | ||
1013 | while (1) { | |
1014 | ||
1015 | conflict = __request_resource(parent, res); | |
1016 | if (!conflict) { | |
1017 | if (!next_res) | |
1018 | break; | |
1019 | res = next_res; | |
1020 | next_res = NULL; | |
1021 | continue; | |
1022 | } | |
1023 | ||
1024 | /* conflict covered whole area */ | |
1025 | if (conflict->start <= res->start && | |
1026 | conflict->end >= res->end) { | |
1027 | free_resource(res); | |
1028 | WARN_ON(next_res); | |
1029 | break; | |
1030 | } | |
1031 | ||
1032 | /* failed, split and try again */ | |
1033 | if (conflict->start > res->start) { | |
1034 | end = res->end; | |
1035 | res->end = conflict->start - 1; | |
1036 | if (conflict->end < end) { | |
1037 | next_res = alloc_resource(GFP_ATOMIC); | |
1038 | if (!next_res) { | |
1039 | free_resource(res); | |
1040 | break; | |
1041 | } | |
1042 | next_res->name = name; | |
1043 | next_res->start = conflict->end + 1; | |
1044 | next_res->end = end; | |
1045 | next_res->flags = type | IORESOURCE_BUSY; | |
1046 | next_res->desc = IORES_DESC_NONE; | |
1047 | } | |
1048 | } else { | |
1049 | res->start = conflict->end + 1; | |
1050 | } | |
1051 | } | |
1052 | ||
1053 | } | |
1054 | ||
1055 | void __init | |
1056 | reserve_region_with_split(struct resource *root, resource_size_t start, | |
1057 | resource_size_t end, const char *name) | |
1058 | { | |
1059 | int abort = 0; | |
1060 | ||
1061 | write_lock(&resource_lock); | |
1062 | if (root->start > start || root->end < end) { | |
1063 | pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", | |
1064 | (unsigned long long)start, (unsigned long long)end, | |
1065 | root); | |
1066 | if (start > root->end || end < root->start) | |
1067 | abort = 1; | |
1068 | else { | |
1069 | if (end > root->end) | |
1070 | end = root->end; | |
1071 | if (start < root->start) | |
1072 | start = root->start; | |
1073 | pr_err("fixing request to [0x%llx-0x%llx]\n", | |
1074 | (unsigned long long)start, | |
1075 | (unsigned long long)end); | |
1076 | } | |
1077 | dump_stack(); | |
1078 | } | |
1079 | if (!abort) | |
1080 | __reserve_region_with_split(root, start, end, name); | |
1081 | write_unlock(&resource_lock); | |
1082 | } | |
1083 | ||
1084 | /** | |
1085 | * resource_alignment - calculate resource's alignment | |
1086 | * @res: resource pointer | |
1087 | * | |
1088 | * Returns alignment on success, 0 (invalid alignment) on failure. | |
1089 | */ | |
1090 | resource_size_t resource_alignment(struct resource *res) | |
1091 | { | |
1092 | switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { | |
1093 | case IORESOURCE_SIZEALIGN: | |
1094 | return resource_size(res); | |
1095 | case IORESOURCE_STARTALIGN: | |
1096 | return res->start; | |
1097 | default: | |
1098 | return 0; | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | /* | |
1103 | * This is compatibility stuff for IO resources. | |
1104 | * | |
1105 | * Note how this, unlike the above, knows about | |
1106 | * the IO flag meanings (busy etc). | |
1107 | * | |
1108 | * request_region creates a new busy region. | |
1109 | * | |
1110 | * release_region releases a matching busy region. | |
1111 | */ | |
1112 | ||
1113 | static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); | |
1114 | ||
1115 | /** | |
1116 | * __request_region - create a new busy resource region | |
1117 | * @parent: parent resource descriptor | |
1118 | * @start: resource start address | |
1119 | * @n: resource region size | |
1120 | * @name: reserving caller's ID string | |
1121 | * @flags: IO resource flags | |
1122 | */ | |
1123 | struct resource * __request_region(struct resource *parent, | |
1124 | resource_size_t start, resource_size_t n, | |
1125 | const char *name, int flags) | |
1126 | { | |
1127 | DECLARE_WAITQUEUE(wait, current); | |
1128 | struct resource *res = alloc_resource(GFP_KERNEL); | |
1129 | struct resource *orig_parent = parent; | |
1130 | ||
1131 | if (!res) | |
1132 | return NULL; | |
1133 | ||
1134 | res->name = name; | |
1135 | res->start = start; | |
1136 | res->end = start + n - 1; | |
1137 | ||
1138 | write_lock(&resource_lock); | |
1139 | ||
1140 | for (;;) { | |
1141 | struct resource *conflict; | |
1142 | ||
1143 | res->flags = resource_type(parent) | resource_ext_type(parent); | |
1144 | res->flags |= IORESOURCE_BUSY | flags; | |
1145 | res->desc = parent->desc; | |
1146 | ||
1147 | conflict = __request_resource(parent, res); | |
1148 | if (!conflict) | |
1149 | break; | |
1150 | /* | |
1151 | * mm/hmm.c reserves physical addresses which then | |
1152 | * become unavailable to other users. Conflicts are | |
1153 | * not expected. Warn to aid debugging if encountered. | |
1154 | */ | |
1155 | if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { | |
1156 | pr_warn("Unaddressable device %s %pR conflicts with %pR", | |
1157 | conflict->name, conflict, res); | |
1158 | } | |
1159 | if (conflict != parent) { | |
1160 | if (!(conflict->flags & IORESOURCE_BUSY)) { | |
1161 | parent = conflict; | |
1162 | continue; | |
1163 | } | |
1164 | } | |
1165 | if (conflict->flags & flags & IORESOURCE_MUXED) { | |
1166 | add_wait_queue(&muxed_resource_wait, &wait); | |
1167 | write_unlock(&resource_lock); | |
1168 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1169 | schedule(); | |
1170 | remove_wait_queue(&muxed_resource_wait, &wait); | |
1171 | write_lock(&resource_lock); | |
1172 | continue; | |
1173 | } | |
1174 | /* Uhhuh, that didn't work out.. */ | |
1175 | free_resource(res); | |
1176 | res = NULL; | |
1177 | break; | |
1178 | } | |
1179 | write_unlock(&resource_lock); | |
1180 | ||
1181 | if (res && orig_parent == &iomem_resource) | |
1182 | revoke_devmem(res); | |
1183 | ||
1184 | return res; | |
1185 | } | |
1186 | EXPORT_SYMBOL(__request_region); | |
1187 | ||
1188 | /** | |
1189 | * __release_region - release a previously reserved resource region | |
1190 | * @parent: parent resource descriptor | |
1191 | * @start: resource start address | |
1192 | * @n: resource region size | |
1193 | * | |
1194 | * The described resource region must match a currently busy region. | |
1195 | */ | |
1196 | void __release_region(struct resource *parent, resource_size_t start, | |
1197 | resource_size_t n) | |
1198 | { | |
1199 | struct resource **p; | |
1200 | resource_size_t end; | |
1201 | ||
1202 | p = &parent->child; | |
1203 | end = start + n - 1; | |
1204 | ||
1205 | write_lock(&resource_lock); | |
1206 | ||
1207 | for (;;) { | |
1208 | struct resource *res = *p; | |
1209 | ||
1210 | if (!res) | |
1211 | break; | |
1212 | if (res->start <= start && res->end >= end) { | |
1213 | if (!(res->flags & IORESOURCE_BUSY)) { | |
1214 | p = &res->child; | |
1215 | continue; | |
1216 | } | |
1217 | if (res->start != start || res->end != end) | |
1218 | break; | |
1219 | *p = res->sibling; | |
1220 | write_unlock(&resource_lock); | |
1221 | if (res->flags & IORESOURCE_MUXED) | |
1222 | wake_up(&muxed_resource_wait); | |
1223 | free_resource(res); | |
1224 | return; | |
1225 | } | |
1226 | p = &res->sibling; | |
1227 | } | |
1228 | ||
1229 | write_unlock(&resource_lock); | |
1230 | ||
1231 | printk(KERN_WARNING "Trying to free nonexistent resource " | |
1232 | "<%016llx-%016llx>\n", (unsigned long long)start, | |
1233 | (unsigned long long)end); | |
1234 | } | |
1235 | EXPORT_SYMBOL(__release_region); | |
1236 | ||
1237 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
1238 | /** | |
1239 | * release_mem_region_adjustable - release a previously reserved memory region | |
1240 | * @parent: parent resource descriptor | |
1241 | * @start: resource start address | |
1242 | * @size: resource region size | |
1243 | * | |
1244 | * This interface is intended for memory hot-delete. The requested region | |
1245 | * is released from a currently busy memory resource. The requested region | |
1246 | * must either match exactly or fit into a single busy resource entry. In | |
1247 | * the latter case, the remaining resource is adjusted accordingly. | |
1248 | * Existing children of the busy memory resource must be immutable in the | |
1249 | * request. | |
1250 | * | |
1251 | * Note: | |
1252 | * - Additional release conditions, such as overlapping region, can be | |
1253 | * supported after they are confirmed as valid cases. | |
1254 | * - When a busy memory resource gets split into two entries, the code | |
1255 | * assumes that all children remain in the lower address entry for | |
1256 | * simplicity. Enhance this logic when necessary. | |
1257 | */ | |
1258 | int release_mem_region_adjustable(struct resource *parent, | |
1259 | resource_size_t start, resource_size_t size) | |
1260 | { | |
1261 | struct resource **p; | |
1262 | struct resource *res; | |
1263 | struct resource *new_res; | |
1264 | resource_size_t end; | |
1265 | int ret = -EINVAL; | |
1266 | ||
1267 | end = start + size - 1; | |
1268 | if ((start < parent->start) || (end > parent->end)) | |
1269 | return ret; | |
1270 | ||
1271 | /* The alloc_resource() result gets checked later */ | |
1272 | new_res = alloc_resource(GFP_KERNEL); | |
1273 | ||
1274 | p = &parent->child; | |
1275 | write_lock(&resource_lock); | |
1276 | ||
1277 | while ((res = *p)) { | |
1278 | if (res->start >= end) | |
1279 | break; | |
1280 | ||
1281 | /* look for the next resource if it does not fit into */ | |
1282 | if (res->start > start || res->end < end) { | |
1283 | p = &res->sibling; | |
1284 | continue; | |
1285 | } | |
1286 | ||
1287 | /* | |
1288 | * All memory regions added from memory-hotplug path have the | |
1289 | * flag IORESOURCE_SYSTEM_RAM. If the resource does not have | |
1290 | * this flag, we know that we are dealing with a resource coming | |
1291 | * from HMM/devm. HMM/devm use another mechanism to add/release | |
1292 | * a resource. This goes via devm_request_mem_region and | |
1293 | * devm_release_mem_region. | |
1294 | * HMM/devm take care to release their resources when they want, | |
1295 | * so if we are dealing with them, let us just back off here. | |
1296 | */ | |
1297 | if (!(res->flags & IORESOURCE_SYSRAM)) { | |
1298 | ret = 0; | |
1299 | break; | |
1300 | } | |
1301 | ||
1302 | if (!(res->flags & IORESOURCE_MEM)) | |
1303 | break; | |
1304 | ||
1305 | if (!(res->flags & IORESOURCE_BUSY)) { | |
1306 | p = &res->child; | |
1307 | continue; | |
1308 | } | |
1309 | ||
1310 | /* found the target resource; let's adjust accordingly */ | |
1311 | if (res->start == start && res->end == end) { | |
1312 | /* free the whole entry */ | |
1313 | *p = res->sibling; | |
1314 | free_resource(res); | |
1315 | ret = 0; | |
1316 | } else if (res->start == start && res->end != end) { | |
1317 | /* adjust the start */ | |
1318 | ret = __adjust_resource(res, end + 1, | |
1319 | res->end - end); | |
1320 | } else if (res->start != start && res->end == end) { | |
1321 | /* adjust the end */ | |
1322 | ret = __adjust_resource(res, res->start, | |
1323 | start - res->start); | |
1324 | } else { | |
1325 | /* split into two entries */ | |
1326 | if (!new_res) { | |
1327 | ret = -ENOMEM; | |
1328 | break; | |
1329 | } | |
1330 | new_res->name = res->name; | |
1331 | new_res->start = end + 1; | |
1332 | new_res->end = res->end; | |
1333 | new_res->flags = res->flags; | |
1334 | new_res->desc = res->desc; | |
1335 | new_res->parent = res->parent; | |
1336 | new_res->sibling = res->sibling; | |
1337 | new_res->child = NULL; | |
1338 | ||
1339 | ret = __adjust_resource(res, res->start, | |
1340 | start - res->start); | |
1341 | if (ret) | |
1342 | break; | |
1343 | res->sibling = new_res; | |
1344 | new_res = NULL; | |
1345 | } | |
1346 | ||
1347 | break; | |
1348 | } | |
1349 | ||
1350 | write_unlock(&resource_lock); | |
1351 | free_resource(new_res); | |
1352 | return ret; | |
1353 | } | |
1354 | #endif /* CONFIG_MEMORY_HOTREMOVE */ | |
1355 | ||
1356 | /* | |
1357 | * Managed region resource | |
1358 | */ | |
1359 | static void devm_resource_release(struct device *dev, void *ptr) | |
1360 | { | |
1361 | struct resource **r = ptr; | |
1362 | ||
1363 | release_resource(*r); | |
1364 | } | |
1365 | ||
1366 | /** | |
1367 | * devm_request_resource() - request and reserve an I/O or memory resource | |
1368 | * @dev: device for which to request the resource | |
1369 | * @root: root of the resource tree from which to request the resource | |
1370 | * @new: descriptor of the resource to request | |
1371 | * | |
1372 | * This is a device-managed version of request_resource(). There is usually | |
1373 | * no need to release resources requested by this function explicitly since | |
1374 | * that will be taken care of when the device is unbound from its driver. | |
1375 | * If for some reason the resource needs to be released explicitly, because | |
1376 | * of ordering issues for example, drivers must call devm_release_resource() | |
1377 | * rather than the regular release_resource(). | |
1378 | * | |
1379 | * When a conflict is detected between any existing resources and the newly | |
1380 | * requested resource, an error message will be printed. | |
1381 | * | |
1382 | * Returns 0 on success or a negative error code on failure. | |
1383 | */ | |
1384 | int devm_request_resource(struct device *dev, struct resource *root, | |
1385 | struct resource *new) | |
1386 | { | |
1387 | struct resource *conflict, **ptr; | |
1388 | ||
1389 | ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); | |
1390 | if (!ptr) | |
1391 | return -ENOMEM; | |
1392 | ||
1393 | *ptr = new; | |
1394 | ||
1395 | conflict = request_resource_conflict(root, new); | |
1396 | if (conflict) { | |
1397 | dev_err(dev, "resource collision: %pR conflicts with %s %pR\n", | |
1398 | new, conflict->name, conflict); | |
1399 | devres_free(ptr); | |
1400 | return -EBUSY; | |
1401 | } | |
1402 | ||
1403 | devres_add(dev, ptr); | |
1404 | return 0; | |
1405 | } | |
1406 | EXPORT_SYMBOL(devm_request_resource); | |
1407 | ||
1408 | static int devm_resource_match(struct device *dev, void *res, void *data) | |
1409 | { | |
1410 | struct resource **ptr = res; | |
1411 | ||
1412 | return *ptr == data; | |
1413 | } | |
1414 | ||
1415 | /** | |
1416 | * devm_release_resource() - release a previously requested resource | |
1417 | * @dev: device for which to release the resource | |
1418 | * @new: descriptor of the resource to release | |
1419 | * | |
1420 | * Releases a resource previously requested using devm_request_resource(). | |
1421 | */ | |
1422 | void devm_release_resource(struct device *dev, struct resource *new) | |
1423 | { | |
1424 | WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, | |
1425 | new)); | |
1426 | } | |
1427 | EXPORT_SYMBOL(devm_release_resource); | |
1428 | ||
1429 | struct region_devres { | |
1430 | struct resource *parent; | |
1431 | resource_size_t start; | |
1432 | resource_size_t n; | |
1433 | }; | |
1434 | ||
1435 | static void devm_region_release(struct device *dev, void *res) | |
1436 | { | |
1437 | struct region_devres *this = res; | |
1438 | ||
1439 | __release_region(this->parent, this->start, this->n); | |
1440 | } | |
1441 | ||
1442 | static int devm_region_match(struct device *dev, void *res, void *match_data) | |
1443 | { | |
1444 | struct region_devres *this = res, *match = match_data; | |
1445 | ||
1446 | return this->parent == match->parent && | |
1447 | this->start == match->start && this->n == match->n; | |
1448 | } | |
1449 | ||
1450 | struct resource * | |
1451 | __devm_request_region(struct device *dev, struct resource *parent, | |
1452 | resource_size_t start, resource_size_t n, const char *name) | |
1453 | { | |
1454 | struct region_devres *dr = NULL; | |
1455 | struct resource *res; | |
1456 | ||
1457 | dr = devres_alloc(devm_region_release, sizeof(struct region_devres), | |
1458 | GFP_KERNEL); | |
1459 | if (!dr) | |
1460 | return NULL; | |
1461 | ||
1462 | dr->parent = parent; | |
1463 | dr->start = start; | |
1464 | dr->n = n; | |
1465 | ||
1466 | res = __request_region(parent, start, n, name, 0); | |
1467 | if (res) | |
1468 | devres_add(dev, dr); | |
1469 | else | |
1470 | devres_free(dr); | |
1471 | ||
1472 | return res; | |
1473 | } | |
1474 | EXPORT_SYMBOL(__devm_request_region); | |
1475 | ||
1476 | void __devm_release_region(struct device *dev, struct resource *parent, | |
1477 | resource_size_t start, resource_size_t n) | |
1478 | { | |
1479 | struct region_devres match_data = { parent, start, n }; | |
1480 | ||
1481 | __release_region(parent, start, n); | |
1482 | WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, | |
1483 | &match_data)); | |
1484 | } | |
1485 | EXPORT_SYMBOL(__devm_release_region); | |
1486 | ||
1487 | /* | |
1488 | * Reserve I/O ports or memory based on "reserve=" kernel parameter. | |
1489 | */ | |
1490 | #define MAXRESERVE 4 | |
1491 | static int __init reserve_setup(char *str) | |
1492 | { | |
1493 | static int reserved; | |
1494 | static struct resource reserve[MAXRESERVE]; | |
1495 | ||
1496 | for (;;) { | |
1497 | unsigned int io_start, io_num; | |
1498 | int x = reserved; | |
1499 | struct resource *parent; | |
1500 | ||
1501 | if (get_option(&str, &io_start) != 2) | |
1502 | break; | |
1503 | if (get_option(&str, &io_num) == 0) | |
1504 | break; | |
1505 | if (x < MAXRESERVE) { | |
1506 | struct resource *res = reserve + x; | |
1507 | ||
1508 | /* | |
1509 | * If the region starts below 0x10000, we assume it's | |
1510 | * I/O port space; otherwise assume it's memory. | |
1511 | */ | |
1512 | if (io_start < 0x10000) { | |
1513 | res->flags = IORESOURCE_IO; | |
1514 | parent = &ioport_resource; | |
1515 | } else { | |
1516 | res->flags = IORESOURCE_MEM; | |
1517 | parent = &iomem_resource; | |
1518 | } | |
1519 | res->name = "reserved"; | |
1520 | res->start = io_start; | |
1521 | res->end = io_start + io_num - 1; | |
1522 | res->flags |= IORESOURCE_BUSY; | |
1523 | res->desc = IORES_DESC_NONE; | |
1524 | res->child = NULL; | |
1525 | if (request_resource(parent, res) == 0) | |
1526 | reserved = x+1; | |
1527 | } | |
1528 | } | |
1529 | return 1; | |
1530 | } | |
1531 | __setup("reserve=", reserve_setup); | |
1532 | ||
1533 | /* | |
1534 | * Check if the requested addr and size spans more than any slot in the | |
1535 | * iomem resource tree. | |
1536 | */ | |
1537 | int iomem_map_sanity_check(resource_size_t addr, unsigned long size) | |
1538 | { | |
1539 | struct resource *p = &iomem_resource; | |
1540 | int err = 0; | |
1541 | loff_t l; | |
1542 | ||
1543 | read_lock(&resource_lock); | |
1544 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { | |
1545 | /* | |
1546 | * We can probably skip the resources without | |
1547 | * IORESOURCE_IO attribute? | |
1548 | */ | |
1549 | if (p->start >= addr + size) | |
1550 | continue; | |
1551 | if (p->end < addr) | |
1552 | continue; | |
1553 | if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && | |
1554 | PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) | |
1555 | continue; | |
1556 | /* | |
1557 | * if a resource is "BUSY", it's not a hardware resource | |
1558 | * but a driver mapping of such a resource; we don't want | |
1559 | * to warn for those; some drivers legitimately map only | |
1560 | * partial hardware resources. (example: vesafb) | |
1561 | */ | |
1562 | if (p->flags & IORESOURCE_BUSY) | |
1563 | continue; | |
1564 | ||
1565 | printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n", | |
1566 | (unsigned long long)addr, | |
1567 | (unsigned long long)(addr + size - 1), | |
1568 | p->name, p); | |
1569 | err = -1; | |
1570 | break; | |
1571 | } | |
1572 | read_unlock(&resource_lock); | |
1573 | ||
1574 | return err; | |
1575 | } | |
1576 | ||
1577 | #ifdef CONFIG_STRICT_DEVMEM | |
1578 | static int strict_iomem_checks = 1; | |
1579 | #else | |
1580 | static int strict_iomem_checks; | |
1581 | #endif | |
1582 | ||
1583 | /* | |
1584 | * check if an address is reserved in the iomem resource tree | |
1585 | * returns true if reserved, false if not reserved. | |
1586 | */ | |
1587 | bool iomem_is_exclusive(u64 addr) | |
1588 | { | |
1589 | struct resource *p = &iomem_resource; | |
1590 | bool err = false; | |
1591 | loff_t l; | |
1592 | int size = PAGE_SIZE; | |
1593 | ||
1594 | if (!strict_iomem_checks) | |
1595 | return false; | |
1596 | ||
1597 | addr = addr & PAGE_MASK; | |
1598 | ||
1599 | read_lock(&resource_lock); | |
1600 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { | |
1601 | /* | |
1602 | * We can probably skip the resources without | |
1603 | * IORESOURCE_IO attribute? | |
1604 | */ | |
1605 | if (p->start >= addr + size) | |
1606 | break; | |
1607 | if (p->end < addr) | |
1608 | continue; | |
1609 | /* | |
1610 | * A resource is exclusive if IORESOURCE_EXCLUSIVE is set | |
1611 | * or CONFIG_IO_STRICT_DEVMEM is enabled and the | |
1612 | * resource is busy. | |
1613 | */ | |
1614 | if ((p->flags & IORESOURCE_BUSY) == 0) | |
1615 | continue; | |
1616 | if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) | |
1617 | || p->flags & IORESOURCE_EXCLUSIVE) { | |
1618 | err = true; | |
1619 | break; | |
1620 | } | |
1621 | } | |
1622 | read_unlock(&resource_lock); | |
1623 | ||
1624 | return err; | |
1625 | } | |
1626 | ||
1627 | struct resource_entry *resource_list_create_entry(struct resource *res, | |
1628 | size_t extra_size) | |
1629 | { | |
1630 | struct resource_entry *entry; | |
1631 | ||
1632 | entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL); | |
1633 | if (entry) { | |
1634 | INIT_LIST_HEAD(&entry->node); | |
1635 | entry->res = res ? res : &entry->__res; | |
1636 | } | |
1637 | ||
1638 | return entry; | |
1639 | } | |
1640 | EXPORT_SYMBOL(resource_list_create_entry); | |
1641 | ||
1642 | void resource_list_free(struct list_head *head) | |
1643 | { | |
1644 | struct resource_entry *entry, *tmp; | |
1645 | ||
1646 | list_for_each_entry_safe(entry, tmp, head, node) | |
1647 | resource_list_destroy_entry(entry); | |
1648 | } | |
1649 | EXPORT_SYMBOL(resource_list_free); | |
1650 | ||
1651 | #ifdef CONFIG_DEVICE_PRIVATE | |
1652 | static struct resource *__request_free_mem_region(struct device *dev, | |
1653 | struct resource *base, unsigned long size, const char *name) | |
1654 | { | |
1655 | resource_size_t end, addr; | |
1656 | struct resource *res; | |
1657 | ||
1658 | size = ALIGN(size, 1UL << PA_SECTION_SHIFT); | |
1659 | end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1); | |
1660 | addr = end - size + 1UL; | |
1661 | ||
1662 | for (; addr > size && addr >= base->start; addr -= size) { | |
1663 | if (region_intersects(addr, size, 0, IORES_DESC_NONE) != | |
1664 | REGION_DISJOINT) | |
1665 | continue; | |
1666 | ||
1667 | if (dev) | |
1668 | res = devm_request_mem_region(dev, addr, size, name); | |
1669 | else | |
1670 | res = request_mem_region(addr, size, name); | |
1671 | if (!res) | |
1672 | return ERR_PTR(-ENOMEM); | |
1673 | res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; | |
1674 | return res; | |
1675 | } | |
1676 | ||
1677 | return ERR_PTR(-ERANGE); | |
1678 | } | |
1679 | ||
1680 | /** | |
1681 | * devm_request_free_mem_region - find free region for device private memory | |
1682 | * | |
1683 | * @dev: device struct to bind the resource to | |
1684 | * @size: size in bytes of the device memory to add | |
1685 | * @base: resource tree to look in | |
1686 | * | |
1687 | * This function tries to find an empty range of physical address big enough to | |
1688 | * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE | |
1689 | * memory, which in turn allocates struct pages. | |
1690 | */ | |
1691 | struct resource *devm_request_free_mem_region(struct device *dev, | |
1692 | struct resource *base, unsigned long size) | |
1693 | { | |
1694 | return __request_free_mem_region(dev, base, size, dev_name(dev)); | |
1695 | } | |
1696 | EXPORT_SYMBOL_GPL(devm_request_free_mem_region); | |
1697 | ||
1698 | struct resource *request_free_mem_region(struct resource *base, | |
1699 | unsigned long size, const char *name) | |
1700 | { | |
1701 | return __request_free_mem_region(NULL, base, size, name); | |
1702 | } | |
1703 | EXPORT_SYMBOL_GPL(request_free_mem_region); | |
1704 | ||
1705 | #endif /* CONFIG_DEVICE_PRIVATE */ | |
1706 | ||
1707 | static int __init strict_iomem(char *str) | |
1708 | { | |
1709 | if (strstr(str, "relaxed")) | |
1710 | strict_iomem_checks = 0; | |
1711 | if (strstr(str, "strict")) | |
1712 | strict_iomem_checks = 1; | |
1713 | return 1; | |
1714 | } | |
1715 | ||
1716 | __setup("iomem=", strict_iomem); |