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1 | /* | |
2 | * linux/kernel/resource.c | |
3 | * | |
4 | * Copyright (C) 1999 Linus Torvalds | |
5 | * Copyright (C) 1999 Martin Mares <mj@ucw.cz> | |
6 | * | |
7 | * Arbitrary resource management. | |
8 | */ | |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/ioport.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/spinlock.h> | |
16 | #include <linux/fs.h> | |
17 | #include <linux/proc_fs.h> | |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/device.h> | |
20 | #include <linux/pfn.h> | |
21 | #include <asm/io.h> | |
22 | ||
23 | ||
24 | struct resource ioport_resource = { | |
25 | .name = "PCI IO", | |
26 | .start = 0, | |
27 | .end = IO_SPACE_LIMIT, | |
28 | .flags = IORESOURCE_IO, | |
29 | }; | |
30 | EXPORT_SYMBOL(ioport_resource); | |
31 | ||
32 | struct resource iomem_resource = { | |
33 | .name = "PCI mem", | |
34 | .start = 0, | |
35 | .end = -1, | |
36 | .flags = IORESOURCE_MEM, | |
37 | }; | |
38 | EXPORT_SYMBOL(iomem_resource); | |
39 | ||
40 | static DEFINE_RWLOCK(resource_lock); | |
41 | ||
42 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | |
43 | { | |
44 | struct resource *p = v; | |
45 | (*pos)++; | |
46 | if (p->child) | |
47 | return p->child; | |
48 | while (!p->sibling && p->parent) | |
49 | p = p->parent; | |
50 | return p->sibling; | |
51 | } | |
52 | ||
53 | #ifdef CONFIG_PROC_FS | |
54 | ||
55 | enum { MAX_IORES_LEVEL = 5 }; | |
56 | ||
57 | static void *r_start(struct seq_file *m, loff_t *pos) | |
58 | __acquires(resource_lock) | |
59 | { | |
60 | struct resource *p = m->private; | |
61 | loff_t l = 0; | |
62 | read_lock(&resource_lock); | |
63 | for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) | |
64 | ; | |
65 | return p; | |
66 | } | |
67 | ||
68 | static void r_stop(struct seq_file *m, void *v) | |
69 | __releases(resource_lock) | |
70 | { | |
71 | read_unlock(&resource_lock); | |
72 | } | |
73 | ||
74 | static int r_show(struct seq_file *m, void *v) | |
75 | { | |
76 | struct resource *root = m->private; | |
77 | struct resource *r = v, *p; | |
78 | int width = root->end < 0x10000 ? 4 : 8; | |
79 | int depth; | |
80 | ||
81 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) | |
82 | if (p->parent == root) | |
83 | break; | |
84 | seq_printf(m, "%*s%0*llx-%0*llx : %s\n", | |
85 | depth * 2, "", | |
86 | width, (unsigned long long) r->start, | |
87 | width, (unsigned long long) r->end, | |
88 | r->name ? r->name : "<BAD>"); | |
89 | return 0; | |
90 | } | |
91 | ||
92 | static const struct seq_operations resource_op = { | |
93 | .start = r_start, | |
94 | .next = r_next, | |
95 | .stop = r_stop, | |
96 | .show = r_show, | |
97 | }; | |
98 | ||
99 | static int ioports_open(struct inode *inode, struct file *file) | |
100 | { | |
101 | int res = seq_open(file, &resource_op); | |
102 | if (!res) { | |
103 | struct seq_file *m = file->private_data; | |
104 | m->private = &ioport_resource; | |
105 | } | |
106 | return res; | |
107 | } | |
108 | ||
109 | static int iomem_open(struct inode *inode, struct file *file) | |
110 | { | |
111 | int res = seq_open(file, &resource_op); | |
112 | if (!res) { | |
113 | struct seq_file *m = file->private_data; | |
114 | m->private = &iomem_resource; | |
115 | } | |
116 | return res; | |
117 | } | |
118 | ||
119 | static const struct file_operations proc_ioports_operations = { | |
120 | .open = ioports_open, | |
121 | .read = seq_read, | |
122 | .llseek = seq_lseek, | |
123 | .release = seq_release, | |
124 | }; | |
125 | ||
126 | static const struct file_operations proc_iomem_operations = { | |
127 | .open = iomem_open, | |
128 | .read = seq_read, | |
129 | .llseek = seq_lseek, | |
130 | .release = seq_release, | |
131 | }; | |
132 | ||
133 | static int __init ioresources_init(void) | |
134 | { | |
135 | proc_create("ioports", 0, NULL, &proc_ioports_operations); | |
136 | proc_create("iomem", 0, NULL, &proc_iomem_operations); | |
137 | return 0; | |
138 | } | |
139 | __initcall(ioresources_init); | |
140 | ||
141 | #endif /* CONFIG_PROC_FS */ | |
142 | ||
143 | /* Return the conflict entry if you can't request it */ | |
144 | static struct resource * __request_resource(struct resource *root, struct resource *new) | |
145 | { | |
146 | resource_size_t start = new->start; | |
147 | resource_size_t end = new->end; | |
148 | struct resource *tmp, **p; | |
149 | ||
150 | if (end < start) | |
151 | return root; | |
152 | if (start < root->start) | |
153 | return root; | |
154 | if (end > root->end) | |
155 | return root; | |
156 | p = &root->child; | |
157 | for (;;) { | |
158 | tmp = *p; | |
159 | if (!tmp || tmp->start > end) { | |
160 | new->sibling = tmp; | |
161 | *p = new; | |
162 | new->parent = root; | |
163 | return NULL; | |
164 | } | |
165 | p = &tmp->sibling; | |
166 | if (tmp->end < start) | |
167 | continue; | |
168 | return tmp; | |
169 | } | |
170 | } | |
171 | ||
172 | static int __release_resource(struct resource *old) | |
173 | { | |
174 | struct resource *tmp, **p; | |
175 | ||
176 | p = &old->parent->child; | |
177 | for (;;) { | |
178 | tmp = *p; | |
179 | if (!tmp) | |
180 | break; | |
181 | if (tmp == old) { | |
182 | *p = tmp->sibling; | |
183 | old->parent = NULL; | |
184 | return 0; | |
185 | } | |
186 | p = &tmp->sibling; | |
187 | } | |
188 | return -EINVAL; | |
189 | } | |
190 | ||
191 | /** | |
192 | * request_resource - request and reserve an I/O or memory resource | |
193 | * @root: root resource descriptor | |
194 | * @new: resource descriptor desired by caller | |
195 | * | |
196 | * Returns 0 for success, negative error code on error. | |
197 | */ | |
198 | int request_resource(struct resource *root, struct resource *new) | |
199 | { | |
200 | struct resource *conflict; | |
201 | ||
202 | write_lock(&resource_lock); | |
203 | conflict = __request_resource(root, new); | |
204 | write_unlock(&resource_lock); | |
205 | return conflict ? -EBUSY : 0; | |
206 | } | |
207 | ||
208 | EXPORT_SYMBOL(request_resource); | |
209 | ||
210 | /** | |
211 | * release_resource - release a previously reserved resource | |
212 | * @old: resource pointer | |
213 | */ | |
214 | int release_resource(struct resource *old) | |
215 | { | |
216 | int retval; | |
217 | ||
218 | write_lock(&resource_lock); | |
219 | retval = __release_resource(old); | |
220 | write_unlock(&resource_lock); | |
221 | return retval; | |
222 | } | |
223 | ||
224 | EXPORT_SYMBOL(release_resource); | |
225 | ||
226 | #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) | |
227 | /* | |
228 | * Finds the lowest memory reosurce exists within [res->start.res->end) | |
229 | * the caller must specify res->start, res->end, res->flags and "name". | |
230 | * If found, returns 0, res is overwritten, if not found, returns -1. | |
231 | */ | |
232 | static int find_next_system_ram(struct resource *res, char *name) | |
233 | { | |
234 | resource_size_t start, end; | |
235 | struct resource *p; | |
236 | ||
237 | BUG_ON(!res); | |
238 | ||
239 | start = res->start; | |
240 | end = res->end; | |
241 | BUG_ON(start >= end); | |
242 | ||
243 | read_lock(&resource_lock); | |
244 | for (p = iomem_resource.child; p ; p = p->sibling) { | |
245 | /* system ram is just marked as IORESOURCE_MEM */ | |
246 | if (p->flags != res->flags) | |
247 | continue; | |
248 | if (name && strcmp(p->name, name)) | |
249 | continue; | |
250 | if (p->start > end) { | |
251 | p = NULL; | |
252 | break; | |
253 | } | |
254 | if ((p->end >= start) && (p->start < end)) | |
255 | break; | |
256 | } | |
257 | read_unlock(&resource_lock); | |
258 | if (!p) | |
259 | return -1; | |
260 | /* copy data */ | |
261 | if (res->start < p->start) | |
262 | res->start = p->start; | |
263 | if (res->end > p->end) | |
264 | res->end = p->end; | |
265 | return 0; | |
266 | } | |
267 | ||
268 | /* | |
269 | * This function calls callback against all memory range of "System RAM" | |
270 | * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. | |
271 | * Now, this function is only for "System RAM". | |
272 | */ | |
273 | int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, | |
274 | void *arg, int (*func)(unsigned long, unsigned long, void *)) | |
275 | { | |
276 | struct resource res; | |
277 | unsigned long pfn, len; | |
278 | u64 orig_end; | |
279 | int ret = -1; | |
280 | ||
281 | res.start = (u64) start_pfn << PAGE_SHIFT; | |
282 | res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; | |
283 | res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; | |
284 | orig_end = res.end; | |
285 | while ((res.start < res.end) && | |
286 | (find_next_system_ram(&res, "System RAM") >= 0)) { | |
287 | pfn = (unsigned long)(res.start >> PAGE_SHIFT); | |
288 | len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT); | |
289 | ret = (*func)(pfn, len, arg); | |
290 | if (ret) | |
291 | break; | |
292 | res.start = res.end + 1; | |
293 | res.end = orig_end; | |
294 | } | |
295 | return ret; | |
296 | } | |
297 | ||
298 | #endif | |
299 | ||
300 | static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) | |
301 | { | |
302 | return 1; | |
303 | } | |
304 | /* | |
305 | * This generic page_is_ram() returns true if specified address is | |
306 | * registered as "System RAM" in iomem_resource list. | |
307 | */ | |
308 | int __attribute__((weak)) page_is_ram(unsigned long pfn) | |
309 | { | |
310 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; | |
311 | } | |
312 | ||
313 | /* | |
314 | * Find empty slot in the resource tree given range and alignment. | |
315 | */ | |
316 | static int find_resource(struct resource *root, struct resource *new, | |
317 | resource_size_t size, resource_size_t min, | |
318 | resource_size_t max, resource_size_t align, | |
319 | void (*alignf)(void *, struct resource *, | |
320 | resource_size_t, resource_size_t), | |
321 | void *alignf_data) | |
322 | { | |
323 | struct resource *this = root->child; | |
324 | ||
325 | new->start = root->start; | |
326 | /* | |
327 | * Skip past an allocated resource that starts at 0, since the assignment | |
328 | * of this->start - 1 to new->end below would cause an underflow. | |
329 | */ | |
330 | if (this && this->start == 0) { | |
331 | new->start = this->end + 1; | |
332 | this = this->sibling; | |
333 | } | |
334 | for(;;) { | |
335 | if (this) | |
336 | new->end = this->start - 1; | |
337 | else | |
338 | new->end = root->end; | |
339 | if (new->start < min) | |
340 | new->start = min; | |
341 | if (new->end > max) | |
342 | new->end = max; | |
343 | new->start = ALIGN(new->start, align); | |
344 | if (alignf) | |
345 | alignf(alignf_data, new, size, align); | |
346 | if (new->start < new->end && new->end - new->start >= size - 1) { | |
347 | new->end = new->start + size - 1; | |
348 | return 0; | |
349 | } | |
350 | if (!this) | |
351 | break; | |
352 | new->start = this->end + 1; | |
353 | this = this->sibling; | |
354 | } | |
355 | return -EBUSY; | |
356 | } | |
357 | ||
358 | /** | |
359 | * allocate_resource - allocate empty slot in the resource tree given range & alignment | |
360 | * @root: root resource descriptor | |
361 | * @new: resource descriptor desired by caller | |
362 | * @size: requested resource region size | |
363 | * @min: minimum size to allocate | |
364 | * @max: maximum size to allocate | |
365 | * @align: alignment requested, in bytes | |
366 | * @alignf: alignment function, optional, called if not NULL | |
367 | * @alignf_data: arbitrary data to pass to the @alignf function | |
368 | */ | |
369 | int allocate_resource(struct resource *root, struct resource *new, | |
370 | resource_size_t size, resource_size_t min, | |
371 | resource_size_t max, resource_size_t align, | |
372 | void (*alignf)(void *, struct resource *, | |
373 | resource_size_t, resource_size_t), | |
374 | void *alignf_data) | |
375 | { | |
376 | int err; | |
377 | ||
378 | write_lock(&resource_lock); | |
379 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); | |
380 | if (err >= 0 && __request_resource(root, new)) | |
381 | err = -EBUSY; | |
382 | write_unlock(&resource_lock); | |
383 | return err; | |
384 | } | |
385 | ||
386 | EXPORT_SYMBOL(allocate_resource); | |
387 | ||
388 | /* | |
389 | * Insert a resource into the resource tree. If successful, return NULL, | |
390 | * otherwise return the conflicting resource (compare to __request_resource()) | |
391 | */ | |
392 | static struct resource * __insert_resource(struct resource *parent, struct resource *new) | |
393 | { | |
394 | struct resource *first, *next; | |
395 | ||
396 | for (;; parent = first) { | |
397 | first = __request_resource(parent, new); | |
398 | if (!first) | |
399 | return first; | |
400 | ||
401 | if (first == parent) | |
402 | return first; | |
403 | ||
404 | if ((first->start > new->start) || (first->end < new->end)) | |
405 | break; | |
406 | if ((first->start == new->start) && (first->end == new->end)) | |
407 | break; | |
408 | } | |
409 | ||
410 | for (next = first; ; next = next->sibling) { | |
411 | /* Partial overlap? Bad, and unfixable */ | |
412 | if (next->start < new->start || next->end > new->end) | |
413 | return next; | |
414 | if (!next->sibling) | |
415 | break; | |
416 | if (next->sibling->start > new->end) | |
417 | break; | |
418 | } | |
419 | ||
420 | new->parent = parent; | |
421 | new->sibling = next->sibling; | |
422 | new->child = first; | |
423 | ||
424 | next->sibling = NULL; | |
425 | for (next = first; next; next = next->sibling) | |
426 | next->parent = new; | |
427 | ||
428 | if (parent->child == first) { | |
429 | parent->child = new; | |
430 | } else { | |
431 | next = parent->child; | |
432 | while (next->sibling != first) | |
433 | next = next->sibling; | |
434 | next->sibling = new; | |
435 | } | |
436 | return NULL; | |
437 | } | |
438 | ||
439 | /** | |
440 | * insert_resource - Inserts a resource in the resource tree | |
441 | * @parent: parent of the new resource | |
442 | * @new: new resource to insert | |
443 | * | |
444 | * Returns 0 on success, -EBUSY if the resource can't be inserted. | |
445 | * | |
446 | * This function is equivalent to request_resource when no conflict | |
447 | * happens. If a conflict happens, and the conflicting resources | |
448 | * entirely fit within the range of the new resource, then the new | |
449 | * resource is inserted and the conflicting resources become children of | |
450 | * the new resource. | |
451 | */ | |
452 | int insert_resource(struct resource *parent, struct resource *new) | |
453 | { | |
454 | struct resource *conflict; | |
455 | ||
456 | write_lock(&resource_lock); | |
457 | conflict = __insert_resource(parent, new); | |
458 | write_unlock(&resource_lock); | |
459 | return conflict ? -EBUSY : 0; | |
460 | } | |
461 | ||
462 | /** | |
463 | * insert_resource_expand_to_fit - Insert a resource into the resource tree | |
464 | * @root: root resource descriptor | |
465 | * @new: new resource to insert | |
466 | * | |
467 | * Insert a resource into the resource tree, possibly expanding it in order | |
468 | * to make it encompass any conflicting resources. | |
469 | */ | |
470 | void insert_resource_expand_to_fit(struct resource *root, struct resource *new) | |
471 | { | |
472 | if (new->parent) | |
473 | return; | |
474 | ||
475 | write_lock(&resource_lock); | |
476 | for (;;) { | |
477 | struct resource *conflict; | |
478 | ||
479 | conflict = __insert_resource(root, new); | |
480 | if (!conflict) | |
481 | break; | |
482 | if (conflict == root) | |
483 | break; | |
484 | ||
485 | /* Ok, expand resource to cover the conflict, then try again .. */ | |
486 | if (conflict->start < new->start) | |
487 | new->start = conflict->start; | |
488 | if (conflict->end > new->end) | |
489 | new->end = conflict->end; | |
490 | ||
491 | printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); | |
492 | } | |
493 | write_unlock(&resource_lock); | |
494 | } | |
495 | ||
496 | /** | |
497 | * adjust_resource - modify a resource's start and size | |
498 | * @res: resource to modify | |
499 | * @start: new start value | |
500 | * @size: new size | |
501 | * | |
502 | * Given an existing resource, change its start and size to match the | |
503 | * arguments. Returns 0 on success, -EBUSY if it can't fit. | |
504 | * Existing children of the resource are assumed to be immutable. | |
505 | */ | |
506 | int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) | |
507 | { | |
508 | struct resource *tmp, *parent = res->parent; | |
509 | resource_size_t end = start + size - 1; | |
510 | int result = -EBUSY; | |
511 | ||
512 | write_lock(&resource_lock); | |
513 | ||
514 | if ((start < parent->start) || (end > parent->end)) | |
515 | goto out; | |
516 | ||
517 | for (tmp = res->child; tmp; tmp = tmp->sibling) { | |
518 | if ((tmp->start < start) || (tmp->end > end)) | |
519 | goto out; | |
520 | } | |
521 | ||
522 | if (res->sibling && (res->sibling->start <= end)) | |
523 | goto out; | |
524 | ||
525 | tmp = parent->child; | |
526 | if (tmp != res) { | |
527 | while (tmp->sibling != res) | |
528 | tmp = tmp->sibling; | |
529 | if (start <= tmp->end) | |
530 | goto out; | |
531 | } | |
532 | ||
533 | res->start = start; | |
534 | res->end = end; | |
535 | result = 0; | |
536 | ||
537 | out: | |
538 | write_unlock(&resource_lock); | |
539 | return result; | |
540 | } | |
541 | ||
542 | static void __init __reserve_region_with_split(struct resource *root, | |
543 | resource_size_t start, resource_size_t end, | |
544 | const char *name) | |
545 | { | |
546 | struct resource *parent = root; | |
547 | struct resource *conflict; | |
548 | struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); | |
549 | ||
550 | if (!res) | |
551 | return; | |
552 | ||
553 | res->name = name; | |
554 | res->start = start; | |
555 | res->end = end; | |
556 | res->flags = IORESOURCE_BUSY; | |
557 | ||
558 | conflict = __request_resource(parent, res); | |
559 | if (!conflict) | |
560 | return; | |
561 | ||
562 | /* failed, split and try again */ | |
563 | kfree(res); | |
564 | ||
565 | /* conflict covered whole area */ | |
566 | if (conflict->start <= start && conflict->end >= end) | |
567 | return; | |
568 | ||
569 | if (conflict->start > start) | |
570 | __reserve_region_with_split(root, start, conflict->start-1, name); | |
571 | if (conflict->end < end) | |
572 | __reserve_region_with_split(root, conflict->end+1, end, name); | |
573 | } | |
574 | ||
575 | void __init reserve_region_with_split(struct resource *root, | |
576 | resource_size_t start, resource_size_t end, | |
577 | const char *name) | |
578 | { | |
579 | write_lock(&resource_lock); | |
580 | __reserve_region_with_split(root, start, end, name); | |
581 | write_unlock(&resource_lock); | |
582 | } | |
583 | ||
584 | EXPORT_SYMBOL(adjust_resource); | |
585 | ||
586 | /** | |
587 | * resource_alignment - calculate resource's alignment | |
588 | * @res: resource pointer | |
589 | * | |
590 | * Returns alignment on success, 0 (invalid alignment) on failure. | |
591 | */ | |
592 | resource_size_t resource_alignment(struct resource *res) | |
593 | { | |
594 | switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { | |
595 | case IORESOURCE_SIZEALIGN: | |
596 | return resource_size(res); | |
597 | case IORESOURCE_STARTALIGN: | |
598 | return res->start; | |
599 | default: | |
600 | return 0; | |
601 | } | |
602 | } | |
603 | ||
604 | /* | |
605 | * This is compatibility stuff for IO resources. | |
606 | * | |
607 | * Note how this, unlike the above, knows about | |
608 | * the IO flag meanings (busy etc). | |
609 | * | |
610 | * request_region creates a new busy region. | |
611 | * | |
612 | * check_region returns non-zero if the area is already busy. | |
613 | * | |
614 | * release_region releases a matching busy region. | |
615 | */ | |
616 | ||
617 | /** | |
618 | * __request_region - create a new busy resource region | |
619 | * @parent: parent resource descriptor | |
620 | * @start: resource start address | |
621 | * @n: resource region size | |
622 | * @name: reserving caller's ID string | |
623 | * @flags: IO resource flags | |
624 | */ | |
625 | struct resource * __request_region(struct resource *parent, | |
626 | resource_size_t start, resource_size_t n, | |
627 | const char *name, int flags) | |
628 | { | |
629 | struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); | |
630 | ||
631 | if (!res) | |
632 | return NULL; | |
633 | ||
634 | res->name = name; | |
635 | res->start = start; | |
636 | res->end = start + n - 1; | |
637 | res->flags = IORESOURCE_BUSY; | |
638 | res->flags |= flags; | |
639 | ||
640 | write_lock(&resource_lock); | |
641 | ||
642 | for (;;) { | |
643 | struct resource *conflict; | |
644 | ||
645 | conflict = __request_resource(parent, res); | |
646 | if (!conflict) | |
647 | break; | |
648 | if (conflict != parent) { | |
649 | parent = conflict; | |
650 | if (!(conflict->flags & IORESOURCE_BUSY)) | |
651 | continue; | |
652 | } | |
653 | ||
654 | /* Uhhuh, that didn't work out.. */ | |
655 | kfree(res); | |
656 | res = NULL; | |
657 | break; | |
658 | } | |
659 | write_unlock(&resource_lock); | |
660 | return res; | |
661 | } | |
662 | EXPORT_SYMBOL(__request_region); | |
663 | ||
664 | /** | |
665 | * __check_region - check if a resource region is busy or free | |
666 | * @parent: parent resource descriptor | |
667 | * @start: resource start address | |
668 | * @n: resource region size | |
669 | * | |
670 | * Returns 0 if the region is free at the moment it is checked, | |
671 | * returns %-EBUSY if the region is busy. | |
672 | * | |
673 | * NOTE: | |
674 | * This function is deprecated because its use is racy. | |
675 | * Even if it returns 0, a subsequent call to request_region() | |
676 | * may fail because another driver etc. just allocated the region. | |
677 | * Do NOT use it. It will be removed from the kernel. | |
678 | */ | |
679 | int __check_region(struct resource *parent, resource_size_t start, | |
680 | resource_size_t n) | |
681 | { | |
682 | struct resource * res; | |
683 | ||
684 | res = __request_region(parent, start, n, "check-region", 0); | |
685 | if (!res) | |
686 | return -EBUSY; | |
687 | ||
688 | release_resource(res); | |
689 | kfree(res); | |
690 | return 0; | |
691 | } | |
692 | EXPORT_SYMBOL(__check_region); | |
693 | ||
694 | /** | |
695 | * __release_region - release a previously reserved resource region | |
696 | * @parent: parent resource descriptor | |
697 | * @start: resource start address | |
698 | * @n: resource region size | |
699 | * | |
700 | * The described resource region must match a currently busy region. | |
701 | */ | |
702 | void __release_region(struct resource *parent, resource_size_t start, | |
703 | resource_size_t n) | |
704 | { | |
705 | struct resource **p; | |
706 | resource_size_t end; | |
707 | ||
708 | p = &parent->child; | |
709 | end = start + n - 1; | |
710 | ||
711 | write_lock(&resource_lock); | |
712 | ||
713 | for (;;) { | |
714 | struct resource *res = *p; | |
715 | ||
716 | if (!res) | |
717 | break; | |
718 | if (res->start <= start && res->end >= end) { | |
719 | if (!(res->flags & IORESOURCE_BUSY)) { | |
720 | p = &res->child; | |
721 | continue; | |
722 | } | |
723 | if (res->start != start || res->end != end) | |
724 | break; | |
725 | *p = res->sibling; | |
726 | write_unlock(&resource_lock); | |
727 | kfree(res); | |
728 | return; | |
729 | } | |
730 | p = &res->sibling; | |
731 | } | |
732 | ||
733 | write_unlock(&resource_lock); | |
734 | ||
735 | printk(KERN_WARNING "Trying to free nonexistent resource " | |
736 | "<%016llx-%016llx>\n", (unsigned long long)start, | |
737 | (unsigned long long)end); | |
738 | } | |
739 | EXPORT_SYMBOL(__release_region); | |
740 | ||
741 | /* | |
742 | * Managed region resource | |
743 | */ | |
744 | struct region_devres { | |
745 | struct resource *parent; | |
746 | resource_size_t start; | |
747 | resource_size_t n; | |
748 | }; | |
749 | ||
750 | static void devm_region_release(struct device *dev, void *res) | |
751 | { | |
752 | struct region_devres *this = res; | |
753 | ||
754 | __release_region(this->parent, this->start, this->n); | |
755 | } | |
756 | ||
757 | static int devm_region_match(struct device *dev, void *res, void *match_data) | |
758 | { | |
759 | struct region_devres *this = res, *match = match_data; | |
760 | ||
761 | return this->parent == match->parent && | |
762 | this->start == match->start && this->n == match->n; | |
763 | } | |
764 | ||
765 | struct resource * __devm_request_region(struct device *dev, | |
766 | struct resource *parent, resource_size_t start, | |
767 | resource_size_t n, const char *name) | |
768 | { | |
769 | struct region_devres *dr = NULL; | |
770 | struct resource *res; | |
771 | ||
772 | dr = devres_alloc(devm_region_release, sizeof(struct region_devres), | |
773 | GFP_KERNEL); | |
774 | if (!dr) | |
775 | return NULL; | |
776 | ||
777 | dr->parent = parent; | |
778 | dr->start = start; | |
779 | dr->n = n; | |
780 | ||
781 | res = __request_region(parent, start, n, name, 0); | |
782 | if (res) | |
783 | devres_add(dev, dr); | |
784 | else | |
785 | devres_free(dr); | |
786 | ||
787 | return res; | |
788 | } | |
789 | EXPORT_SYMBOL(__devm_request_region); | |
790 | ||
791 | void __devm_release_region(struct device *dev, struct resource *parent, | |
792 | resource_size_t start, resource_size_t n) | |
793 | { | |
794 | struct region_devres match_data = { parent, start, n }; | |
795 | ||
796 | __release_region(parent, start, n); | |
797 | WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, | |
798 | &match_data)); | |
799 | } | |
800 | EXPORT_SYMBOL(__devm_release_region); | |
801 | ||
802 | /* | |
803 | * Called from init/main.c to reserve IO ports. | |
804 | */ | |
805 | #define MAXRESERVE 4 | |
806 | static int __init reserve_setup(char *str) | |
807 | { | |
808 | static int reserved; | |
809 | static struct resource reserve[MAXRESERVE]; | |
810 | ||
811 | for (;;) { | |
812 | unsigned int io_start, io_num; | |
813 | int x = reserved; | |
814 | ||
815 | if (get_option (&str, &io_start) != 2) | |
816 | break; | |
817 | if (get_option (&str, &io_num) == 0) | |
818 | break; | |
819 | if (x < MAXRESERVE) { | |
820 | struct resource *res = reserve + x; | |
821 | res->name = "reserved"; | |
822 | res->start = io_start; | |
823 | res->end = io_start + io_num - 1; | |
824 | res->flags = IORESOURCE_BUSY; | |
825 | res->child = NULL; | |
826 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) | |
827 | reserved = x+1; | |
828 | } | |
829 | } | |
830 | return 1; | |
831 | } | |
832 | ||
833 | __setup("reserve=", reserve_setup); | |
834 | ||
835 | /* | |
836 | * Check if the requested addr and size spans more than any slot in the | |
837 | * iomem resource tree. | |
838 | */ | |
839 | int iomem_map_sanity_check(resource_size_t addr, unsigned long size) | |
840 | { | |
841 | struct resource *p = &iomem_resource; | |
842 | int err = 0; | |
843 | loff_t l; | |
844 | ||
845 | read_lock(&resource_lock); | |
846 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { | |
847 | /* | |
848 | * We can probably skip the resources without | |
849 | * IORESOURCE_IO attribute? | |
850 | */ | |
851 | if (p->start >= addr + size) | |
852 | continue; | |
853 | if (p->end < addr) | |
854 | continue; | |
855 | if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && | |
856 | PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) | |
857 | continue; | |
858 | /* | |
859 | * if a resource is "BUSY", it's not a hardware resource | |
860 | * but a driver mapping of such a resource; we don't want | |
861 | * to warn for those; some drivers legitimately map only | |
862 | * partial hardware resources. (example: vesafb) | |
863 | */ | |
864 | if (p->flags & IORESOURCE_BUSY) | |
865 | continue; | |
866 | ||
867 | printk(KERN_WARNING "resource map sanity check conflict: " | |
868 | "0x%llx 0x%llx 0x%llx 0x%llx %s\n", | |
869 | (unsigned long long)addr, | |
870 | (unsigned long long)(addr + size - 1), | |
871 | (unsigned long long)p->start, | |
872 | (unsigned long long)p->end, | |
873 | p->name); | |
874 | err = -1; | |
875 | break; | |
876 | } | |
877 | read_unlock(&resource_lock); | |
878 | ||
879 | return err; | |
880 | } | |
881 | ||
882 | #ifdef CONFIG_STRICT_DEVMEM | |
883 | static int strict_iomem_checks = 1; | |
884 | #else | |
885 | static int strict_iomem_checks; | |
886 | #endif | |
887 | ||
888 | /* | |
889 | * check if an address is reserved in the iomem resource tree | |
890 | * returns 1 if reserved, 0 if not reserved. | |
891 | */ | |
892 | int iomem_is_exclusive(u64 addr) | |
893 | { | |
894 | struct resource *p = &iomem_resource; | |
895 | int err = 0; | |
896 | loff_t l; | |
897 | int size = PAGE_SIZE; | |
898 | ||
899 | if (!strict_iomem_checks) | |
900 | return 0; | |
901 | ||
902 | addr = addr & PAGE_MASK; | |
903 | ||
904 | read_lock(&resource_lock); | |
905 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { | |
906 | /* | |
907 | * We can probably skip the resources without | |
908 | * IORESOURCE_IO attribute? | |
909 | */ | |
910 | if (p->start >= addr + size) | |
911 | break; | |
912 | if (p->end < addr) | |
913 | continue; | |
914 | if (p->flags & IORESOURCE_BUSY && | |
915 | p->flags & IORESOURCE_EXCLUSIVE) { | |
916 | err = 1; | |
917 | break; | |
918 | } | |
919 | } | |
920 | read_unlock(&resource_lock); | |
921 | ||
922 | return err; | |
923 | } | |
924 | ||
925 | static int __init strict_iomem(char *str) | |
926 | { | |
927 | if (strstr(str, "relaxed")) | |
928 | strict_iomem_checks = 0; | |
929 | if (strstr(str, "strict")) | |
930 | strict_iomem_checks = 1; | |
931 | return 1; | |
932 | } | |
933 | ||
934 | __setup("iomem=", strict_iomem); |