Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
10 | #include <linux/module.h> |
11 | #include <linux/sched.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/ioport.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/spinlock.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/proc_fs.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <asm/io.h> | |
21 | ||
22 | ||
23 | struct resource ioport_resource = { | |
24 | .name = "PCI IO", | |
6550e07f | 25 | .start = 0, |
1da177e4 LT |
26 | .end = IO_SPACE_LIMIT, |
27 | .flags = IORESOURCE_IO, | |
28 | }; | |
1da177e4 LT |
29 | EXPORT_SYMBOL(ioport_resource); |
30 | ||
31 | struct resource iomem_resource = { | |
32 | .name = "PCI mem", | |
6550e07f GKH |
33 | .start = 0, |
34 | .end = -1, | |
1da177e4 LT |
35 | .flags = IORESOURCE_MEM, |
36 | }; | |
1da177e4 LT |
37 | EXPORT_SYMBOL(iomem_resource); |
38 | ||
39 | static DEFINE_RWLOCK(resource_lock); | |
40 | ||
41 | #ifdef CONFIG_PROC_FS | |
42 | ||
43 | enum { MAX_IORES_LEVEL = 5 }; | |
44 | ||
45 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | |
46 | { | |
47 | struct resource *p = v; | |
48 | (*pos)++; | |
49 | if (p->child) | |
50 | return p->child; | |
51 | while (!p->sibling && p->parent) | |
52 | p = p->parent; | |
53 | return p->sibling; | |
54 | } | |
55 | ||
56 | static void *r_start(struct seq_file *m, loff_t *pos) | |
57 | __acquires(resource_lock) | |
58 | { | |
59 | struct resource *p = m->private; | |
60 | loff_t l = 0; | |
61 | read_lock(&resource_lock); | |
62 | for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) | |
63 | ; | |
64 | return p; | |
65 | } | |
66 | ||
67 | static void r_stop(struct seq_file *m, void *v) | |
68 | __releases(resource_lock) | |
69 | { | |
70 | read_unlock(&resource_lock); | |
71 | } | |
72 | ||
73 | static int r_show(struct seq_file *m, void *v) | |
74 | { | |
75 | struct resource *root = m->private; | |
76 | struct resource *r = v, *p; | |
77 | int width = root->end < 0x10000 ? 4 : 8; | |
78 | int depth; | |
79 | ||
80 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) | |
81 | if (p->parent == root) | |
82 | break; | |
685143ac | 83 | seq_printf(m, "%*s%0*llx-%0*llx : %s\n", |
1da177e4 | 84 | depth * 2, "", |
685143ac GKH |
85 | width, (unsigned long long) r->start, |
86 | width, (unsigned long long) r->end, | |
1da177e4 LT |
87 | r->name ? r->name : "<BAD>"); |
88 | return 0; | |
89 | } | |
90 | ||
15ad7cdc | 91 | static const struct seq_operations resource_op = { |
1da177e4 LT |
92 | .start = r_start, |
93 | .next = r_next, | |
94 | .stop = r_stop, | |
95 | .show = r_show, | |
96 | }; | |
97 | ||
98 | static int ioports_open(struct inode *inode, struct file *file) | |
99 | { | |
100 | int res = seq_open(file, &resource_op); | |
101 | if (!res) { | |
102 | struct seq_file *m = file->private_data; | |
103 | m->private = &ioport_resource; | |
104 | } | |
105 | return res; | |
106 | } | |
107 | ||
108 | static int iomem_open(struct inode *inode, struct file *file) | |
109 | { | |
110 | int res = seq_open(file, &resource_op); | |
111 | if (!res) { | |
112 | struct seq_file *m = file->private_data; | |
113 | m->private = &iomem_resource; | |
114 | } | |
115 | return res; | |
116 | } | |
117 | ||
15ad7cdc | 118 | static const struct file_operations proc_ioports_operations = { |
1da177e4 LT |
119 | .open = ioports_open, |
120 | .read = seq_read, | |
121 | .llseek = seq_lseek, | |
122 | .release = seq_release, | |
123 | }; | |
124 | ||
15ad7cdc | 125 | static const struct file_operations proc_iomem_operations = { |
1da177e4 LT |
126 | .open = iomem_open, |
127 | .read = seq_read, | |
128 | .llseek = seq_lseek, | |
129 | .release = seq_release, | |
130 | }; | |
131 | ||
132 | static int __init ioresources_init(void) | |
133 | { | |
134 | struct proc_dir_entry *entry; | |
135 | ||
136 | entry = create_proc_entry("ioports", 0, NULL); | |
137 | if (entry) | |
138 | entry->proc_fops = &proc_ioports_operations; | |
139 | entry = create_proc_entry("iomem", 0, NULL); | |
140 | if (entry) | |
141 | entry->proc_fops = &proc_iomem_operations; | |
142 | return 0; | |
143 | } | |
144 | __initcall(ioresources_init); | |
145 | ||
146 | #endif /* CONFIG_PROC_FS */ | |
147 | ||
148 | /* Return the conflict entry if you can't request it */ | |
149 | static struct resource * __request_resource(struct resource *root, struct resource *new) | |
150 | { | |
d75fc8bb GKH |
151 | resource_size_t start = new->start; |
152 | resource_size_t end = new->end; | |
1da177e4 LT |
153 | struct resource *tmp, **p; |
154 | ||
155 | if (end < start) | |
156 | return root; | |
157 | if (start < root->start) | |
158 | return root; | |
159 | if (end > root->end) | |
160 | return root; | |
161 | p = &root->child; | |
162 | for (;;) { | |
163 | tmp = *p; | |
164 | if (!tmp || tmp->start > end) { | |
165 | new->sibling = tmp; | |
166 | *p = new; | |
167 | new->parent = root; | |
168 | return NULL; | |
169 | } | |
170 | p = &tmp->sibling; | |
171 | if (tmp->end < start) | |
172 | continue; | |
173 | return tmp; | |
174 | } | |
175 | } | |
176 | ||
177 | static int __release_resource(struct resource *old) | |
178 | { | |
179 | struct resource *tmp, **p; | |
180 | ||
181 | p = &old->parent->child; | |
182 | for (;;) { | |
183 | tmp = *p; | |
184 | if (!tmp) | |
185 | break; | |
186 | if (tmp == old) { | |
187 | *p = tmp->sibling; | |
188 | old->parent = NULL; | |
189 | return 0; | |
190 | } | |
191 | p = &tmp->sibling; | |
192 | } | |
193 | return -EINVAL; | |
194 | } | |
195 | ||
e1ca66d1 RD |
196 | /** |
197 | * request_resource - request and reserve an I/O or memory resource | |
198 | * @root: root resource descriptor | |
199 | * @new: resource descriptor desired by caller | |
200 | * | |
201 | * Returns 0 for success, negative error code on error. | |
202 | */ | |
1da177e4 LT |
203 | int request_resource(struct resource *root, struct resource *new) |
204 | { | |
205 | struct resource *conflict; | |
206 | ||
207 | write_lock(&resource_lock); | |
208 | conflict = __request_resource(root, new); | |
209 | write_unlock(&resource_lock); | |
210 | return conflict ? -EBUSY : 0; | |
211 | } | |
212 | ||
213 | EXPORT_SYMBOL(request_resource); | |
214 | ||
e1ca66d1 RD |
215 | /** |
216 | * ____request_resource - reserve a resource, with resource conflict returned | |
217 | * @root: root resource descriptor | |
218 | * @new: resource descriptor desired by caller | |
219 | * | |
220 | * Returns: | |
221 | * On success, NULL is returned. | |
222 | * On error, a pointer to the conflicting resource is returned. | |
223 | */ | |
1da177e4 LT |
224 | struct resource *____request_resource(struct resource *root, struct resource *new) |
225 | { | |
226 | struct resource *conflict; | |
227 | ||
228 | write_lock(&resource_lock); | |
229 | conflict = __request_resource(root, new); | |
230 | write_unlock(&resource_lock); | |
231 | return conflict; | |
232 | } | |
233 | ||
234 | EXPORT_SYMBOL(____request_resource); | |
235 | ||
e1ca66d1 RD |
236 | /** |
237 | * release_resource - release a previously reserved resource | |
238 | * @old: resource pointer | |
239 | */ | |
1da177e4 LT |
240 | int release_resource(struct resource *old) |
241 | { | |
242 | int retval; | |
243 | ||
244 | write_lock(&resource_lock); | |
245 | retval = __release_resource(old); | |
246 | write_unlock(&resource_lock); | |
247 | return retval; | |
248 | } | |
249 | ||
250 | EXPORT_SYMBOL(release_resource); | |
251 | ||
2842f114 KH |
252 | #ifdef CONFIG_MEMORY_HOTPLUG |
253 | /* | |
254 | * Finds the lowest memory reosurce exists within [res->start.res->end) | |
255 | * the caller must specify res->start, res->end, res->flags. | |
256 | * If found, returns 0, res is overwritten, if not found, returns -1. | |
257 | */ | |
258 | int find_next_system_ram(struct resource *res) | |
259 | { | |
260 | resource_size_t start, end; | |
261 | struct resource *p; | |
262 | ||
263 | BUG_ON(!res); | |
264 | ||
265 | start = res->start; | |
266 | end = res->end; | |
58c1b5b0 | 267 | BUG_ON(start >= end); |
2842f114 KH |
268 | |
269 | read_lock(&resource_lock); | |
270 | for (p = iomem_resource.child; p ; p = p->sibling) { | |
271 | /* system ram is just marked as IORESOURCE_MEM */ | |
272 | if (p->flags != res->flags) | |
273 | continue; | |
274 | if (p->start > end) { | |
275 | p = NULL; | |
276 | break; | |
277 | } | |
58c1b5b0 | 278 | if ((p->end >= start) && (p->start < end)) |
2842f114 KH |
279 | break; |
280 | } | |
281 | read_unlock(&resource_lock); | |
282 | if (!p) | |
283 | return -1; | |
284 | /* copy data */ | |
0f04ab5e KH |
285 | if (res->start < p->start) |
286 | res->start = p->start; | |
287 | if (res->end > p->end) | |
288 | res->end = p->end; | |
2842f114 KH |
289 | return 0; |
290 | } | |
291 | #endif | |
292 | ||
1da177e4 LT |
293 | /* |
294 | * Find empty slot in the resource tree given range and alignment. | |
295 | */ | |
296 | static int find_resource(struct resource *root, struct resource *new, | |
d75fc8bb GKH |
297 | resource_size_t size, resource_size_t min, |
298 | resource_size_t max, resource_size_t align, | |
1da177e4 | 299 | void (*alignf)(void *, struct resource *, |
d75fc8bb | 300 | resource_size_t, resource_size_t), |
1da177e4 LT |
301 | void *alignf_data) |
302 | { | |
303 | struct resource *this = root->child; | |
304 | ||
305 | new->start = root->start; | |
306 | /* | |
307 | * Skip past an allocated resource that starts at 0, since the assignment | |
308 | * of this->start - 1 to new->end below would cause an underflow. | |
309 | */ | |
310 | if (this && this->start == 0) { | |
311 | new->start = this->end + 1; | |
312 | this = this->sibling; | |
313 | } | |
314 | for(;;) { | |
315 | if (this) | |
316 | new->end = this->start - 1; | |
317 | else | |
318 | new->end = root->end; | |
319 | if (new->start < min) | |
320 | new->start = min; | |
321 | if (new->end > max) | |
322 | new->end = max; | |
8c0e33c1 | 323 | new->start = ALIGN(new->start, align); |
1da177e4 LT |
324 | if (alignf) |
325 | alignf(alignf_data, new, size, align); | |
b52402c7 | 326 | if (new->start < new->end && new->end - new->start >= size - 1) { |
1da177e4 LT |
327 | new->end = new->start + size - 1; |
328 | return 0; | |
329 | } | |
330 | if (!this) | |
331 | break; | |
332 | new->start = this->end + 1; | |
333 | this = this->sibling; | |
334 | } | |
335 | return -EBUSY; | |
336 | } | |
337 | ||
e1ca66d1 RD |
338 | /** |
339 | * allocate_resource - allocate empty slot in the resource tree given range & alignment | |
340 | * @root: root resource descriptor | |
341 | * @new: resource descriptor desired by caller | |
342 | * @size: requested resource region size | |
343 | * @min: minimum size to allocate | |
344 | * @max: maximum size to allocate | |
345 | * @align: alignment requested, in bytes | |
346 | * @alignf: alignment function, optional, called if not NULL | |
347 | * @alignf_data: arbitrary data to pass to the @alignf function | |
1da177e4 LT |
348 | */ |
349 | int allocate_resource(struct resource *root, struct resource *new, | |
d75fc8bb GKH |
350 | resource_size_t size, resource_size_t min, |
351 | resource_size_t max, resource_size_t align, | |
1da177e4 | 352 | void (*alignf)(void *, struct resource *, |
d75fc8bb | 353 | resource_size_t, resource_size_t), |
1da177e4 LT |
354 | void *alignf_data) |
355 | { | |
356 | int err; | |
357 | ||
358 | write_lock(&resource_lock); | |
359 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); | |
360 | if (err >= 0 && __request_resource(root, new)) | |
361 | err = -EBUSY; | |
362 | write_unlock(&resource_lock); | |
363 | return err; | |
364 | } | |
365 | ||
366 | EXPORT_SYMBOL(allocate_resource); | |
367 | ||
368 | /** | |
369 | * insert_resource - Inserts a resource in the resource tree | |
370 | * @parent: parent of the new resource | |
371 | * @new: new resource to insert | |
372 | * | |
373 | * Returns 0 on success, -EBUSY if the resource can't be inserted. | |
374 | * | |
d33b6fba | 375 | * This function is equivalent to request_resource when no conflict |
1da177e4 LT |
376 | * happens. If a conflict happens, and the conflicting resources |
377 | * entirely fit within the range of the new resource, then the new | |
d33b6fba MW |
378 | * resource is inserted and the conflicting resources become children of |
379 | * the new resource. | |
1da177e4 LT |
380 | */ |
381 | int insert_resource(struct resource *parent, struct resource *new) | |
382 | { | |
383 | int result; | |
384 | struct resource *first, *next; | |
385 | ||
386 | write_lock(&resource_lock); | |
d33b6fba MW |
387 | |
388 | for (;; parent = first) { | |
389 | result = 0; | |
390 | first = __request_resource(parent, new); | |
391 | if (!first) | |
392 | goto out; | |
393 | ||
394 | result = -EBUSY; | |
395 | if (first == parent) | |
396 | goto out; | |
397 | ||
398 | if ((first->start > new->start) || (first->end < new->end)) | |
399 | break; | |
400 | if ((first->start == new->start) && (first->end == new->end)) | |
401 | break; | |
1da177e4 LT |
402 | } |
403 | ||
404 | for (next = first; ; next = next->sibling) { | |
405 | /* Partial overlap? Bad, and unfixable */ | |
406 | if (next->start < new->start || next->end > new->end) | |
407 | goto out; | |
408 | if (!next->sibling) | |
409 | break; | |
410 | if (next->sibling->start > new->end) | |
411 | break; | |
412 | } | |
413 | ||
414 | result = 0; | |
415 | ||
416 | new->parent = parent; | |
417 | new->sibling = next->sibling; | |
418 | new->child = first; | |
419 | ||
420 | next->sibling = NULL; | |
421 | for (next = first; next; next = next->sibling) | |
422 | next->parent = new; | |
423 | ||
424 | if (parent->child == first) { | |
425 | parent->child = new; | |
426 | } else { | |
427 | next = parent->child; | |
428 | while (next->sibling != first) | |
429 | next = next->sibling; | |
430 | next->sibling = new; | |
431 | } | |
432 | ||
433 | out: | |
434 | write_unlock(&resource_lock); | |
435 | return result; | |
436 | } | |
437 | ||
e1ca66d1 RD |
438 | /** |
439 | * adjust_resource - modify a resource's start and size | |
440 | * @res: resource to modify | |
441 | * @start: new start value | |
442 | * @size: new size | |
443 | * | |
1da177e4 | 444 | * Given an existing resource, change its start and size to match the |
e1ca66d1 RD |
445 | * arguments. Returns 0 on success, -EBUSY if it can't fit. |
446 | * Existing children of the resource are assumed to be immutable. | |
1da177e4 | 447 | */ |
d75fc8bb | 448 | int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) |
1da177e4 LT |
449 | { |
450 | struct resource *tmp, *parent = res->parent; | |
d75fc8bb | 451 | resource_size_t end = start + size - 1; |
1da177e4 LT |
452 | int result = -EBUSY; |
453 | ||
454 | write_lock(&resource_lock); | |
455 | ||
456 | if ((start < parent->start) || (end > parent->end)) | |
457 | goto out; | |
458 | ||
459 | for (tmp = res->child; tmp; tmp = tmp->sibling) { | |
460 | if ((tmp->start < start) || (tmp->end > end)) | |
461 | goto out; | |
462 | } | |
463 | ||
464 | if (res->sibling && (res->sibling->start <= end)) | |
465 | goto out; | |
466 | ||
467 | tmp = parent->child; | |
468 | if (tmp != res) { | |
469 | while (tmp->sibling != res) | |
470 | tmp = tmp->sibling; | |
471 | if (start <= tmp->end) | |
472 | goto out; | |
473 | } | |
474 | ||
475 | res->start = start; | |
476 | res->end = end; | |
477 | result = 0; | |
478 | ||
479 | out: | |
480 | write_unlock(&resource_lock); | |
481 | return result; | |
482 | } | |
483 | ||
484 | EXPORT_SYMBOL(adjust_resource); | |
485 | ||
486 | /* | |
487 | * This is compatibility stuff for IO resources. | |
488 | * | |
489 | * Note how this, unlike the above, knows about | |
490 | * the IO flag meanings (busy etc). | |
491 | * | |
e1ca66d1 | 492 | * request_region creates a new busy region. |
1da177e4 | 493 | * |
e1ca66d1 | 494 | * check_region returns non-zero if the area is already busy. |
1da177e4 | 495 | * |
e1ca66d1 RD |
496 | * release_region releases a matching busy region. |
497 | */ | |
498 | ||
499 | /** | |
500 | * __request_region - create a new busy resource region | |
501 | * @parent: parent resource descriptor | |
502 | * @start: resource start address | |
503 | * @n: resource region size | |
504 | * @name: reserving caller's ID string | |
1da177e4 | 505 | */ |
d75fc8bb GKH |
506 | struct resource * __request_region(struct resource *parent, |
507 | resource_size_t start, resource_size_t n, | |
508 | const char *name) | |
1da177e4 | 509 | { |
dd392710 | 510 | struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); |
1da177e4 LT |
511 | |
512 | if (res) { | |
1da177e4 LT |
513 | res->name = name; |
514 | res->start = start; | |
515 | res->end = start + n - 1; | |
516 | res->flags = IORESOURCE_BUSY; | |
517 | ||
518 | write_lock(&resource_lock); | |
519 | ||
520 | for (;;) { | |
521 | struct resource *conflict; | |
522 | ||
523 | conflict = __request_resource(parent, res); | |
524 | if (!conflict) | |
525 | break; | |
526 | if (conflict != parent) { | |
527 | parent = conflict; | |
528 | if (!(conflict->flags & IORESOURCE_BUSY)) | |
529 | continue; | |
530 | } | |
531 | ||
532 | /* Uhhuh, that didn't work out.. */ | |
533 | kfree(res); | |
534 | res = NULL; | |
535 | break; | |
536 | } | |
537 | write_unlock(&resource_lock); | |
538 | } | |
539 | return res; | |
540 | } | |
1da177e4 LT |
541 | EXPORT_SYMBOL(__request_region); |
542 | ||
e1ca66d1 RD |
543 | /** |
544 | * __check_region - check if a resource region is busy or free | |
545 | * @parent: parent resource descriptor | |
546 | * @start: resource start address | |
547 | * @n: resource region size | |
548 | * | |
549 | * Returns 0 if the region is free at the moment it is checked, | |
550 | * returns %-EBUSY if the region is busy. | |
551 | * | |
552 | * NOTE: | |
553 | * This function is deprecated because its use is racy. | |
554 | * Even if it returns 0, a subsequent call to request_region() | |
555 | * may fail because another driver etc. just allocated the region. | |
556 | * Do NOT use it. It will be removed from the kernel. | |
557 | */ | |
d75fc8bb GKH |
558 | int __check_region(struct resource *parent, resource_size_t start, |
559 | resource_size_t n) | |
1da177e4 LT |
560 | { |
561 | struct resource * res; | |
562 | ||
563 | res = __request_region(parent, start, n, "check-region"); | |
564 | if (!res) | |
565 | return -EBUSY; | |
566 | ||
567 | release_resource(res); | |
568 | kfree(res); | |
569 | return 0; | |
570 | } | |
1da177e4 LT |
571 | EXPORT_SYMBOL(__check_region); |
572 | ||
e1ca66d1 RD |
573 | /** |
574 | * __release_region - release a previously reserved resource region | |
575 | * @parent: parent resource descriptor | |
576 | * @start: resource start address | |
577 | * @n: resource region size | |
578 | * | |
579 | * The described resource region must match a currently busy region. | |
580 | */ | |
d75fc8bb GKH |
581 | void __release_region(struct resource *parent, resource_size_t start, |
582 | resource_size_t n) | |
1da177e4 LT |
583 | { |
584 | struct resource **p; | |
d75fc8bb | 585 | resource_size_t end; |
1da177e4 LT |
586 | |
587 | p = &parent->child; | |
588 | end = start + n - 1; | |
589 | ||
590 | write_lock(&resource_lock); | |
591 | ||
592 | for (;;) { | |
593 | struct resource *res = *p; | |
594 | ||
595 | if (!res) | |
596 | break; | |
597 | if (res->start <= start && res->end >= end) { | |
598 | if (!(res->flags & IORESOURCE_BUSY)) { | |
599 | p = &res->child; | |
600 | continue; | |
601 | } | |
602 | if (res->start != start || res->end != end) | |
603 | break; | |
604 | *p = res->sibling; | |
605 | write_unlock(&resource_lock); | |
606 | kfree(res); | |
607 | return; | |
608 | } | |
609 | p = &res->sibling; | |
610 | } | |
611 | ||
612 | write_unlock(&resource_lock); | |
613 | ||
685143ac GKH |
614 | printk(KERN_WARNING "Trying to free nonexistent resource " |
615 | "<%016llx-%016llx>\n", (unsigned long long)start, | |
616 | (unsigned long long)end); | |
1da177e4 | 617 | } |
1da177e4 LT |
618 | EXPORT_SYMBOL(__release_region); |
619 | ||
620 | /* | |
621 | * Called from init/main.c to reserve IO ports. | |
622 | */ | |
623 | #define MAXRESERVE 4 | |
624 | static int __init reserve_setup(char *str) | |
625 | { | |
626 | static int reserved; | |
627 | static struct resource reserve[MAXRESERVE]; | |
628 | ||
629 | for (;;) { | |
630 | int io_start, io_num; | |
631 | int x = reserved; | |
632 | ||
633 | if (get_option (&str, &io_start) != 2) | |
634 | break; | |
635 | if (get_option (&str, &io_num) == 0) | |
636 | break; | |
637 | if (x < MAXRESERVE) { | |
638 | struct resource *res = reserve + x; | |
639 | res->name = "reserved"; | |
640 | res->start = io_start; | |
641 | res->end = io_start + io_num - 1; | |
642 | res->flags = IORESOURCE_BUSY; | |
643 | res->child = NULL; | |
644 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) | |
645 | reserved = x+1; | |
646 | } | |
647 | } | |
648 | return 1; | |
649 | } | |
650 | ||
651 | __setup("reserve=", reserve_setup); |