]>
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 | ||
91 | static struct seq_operations resource_op = { | |
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 | ||
118 | static struct file_operations proc_ioports_operations = { | |
119 | .open = ioports_open, | |
120 | .read = seq_read, | |
121 | .llseek = seq_lseek, | |
122 | .release = seq_release, | |
123 | }; | |
124 | ||
125 | static struct file_operations proc_iomem_operations = { | |
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 | ||
196 | int request_resource(struct resource *root, struct resource *new) | |
197 | { | |
198 | struct resource *conflict; | |
199 | ||
200 | write_lock(&resource_lock); | |
201 | conflict = __request_resource(root, new); | |
202 | write_unlock(&resource_lock); | |
203 | return conflict ? -EBUSY : 0; | |
204 | } | |
205 | ||
206 | EXPORT_SYMBOL(request_resource); | |
207 | ||
208 | struct resource *____request_resource(struct resource *root, struct resource *new) | |
209 | { | |
210 | struct resource *conflict; | |
211 | ||
212 | write_lock(&resource_lock); | |
213 | conflict = __request_resource(root, new); | |
214 | write_unlock(&resource_lock); | |
215 | return conflict; | |
216 | } | |
217 | ||
218 | EXPORT_SYMBOL(____request_resource); | |
219 | ||
220 | int release_resource(struct resource *old) | |
221 | { | |
222 | int retval; | |
223 | ||
224 | write_lock(&resource_lock); | |
225 | retval = __release_resource(old); | |
226 | write_unlock(&resource_lock); | |
227 | return retval; | |
228 | } | |
229 | ||
230 | EXPORT_SYMBOL(release_resource); | |
231 | ||
2842f114 KH |
232 | #ifdef CONFIG_MEMORY_HOTPLUG |
233 | /* | |
234 | * Finds the lowest memory reosurce exists within [res->start.res->end) | |
235 | * the caller must specify res->start, res->end, res->flags. | |
236 | * If found, returns 0, res is overwritten, if not found, returns -1. | |
237 | */ | |
238 | int find_next_system_ram(struct resource *res) | |
239 | { | |
240 | resource_size_t start, end; | |
241 | struct resource *p; | |
242 | ||
243 | BUG_ON(!res); | |
244 | ||
245 | start = res->start; | |
246 | end = res->end; | |
247 | ||
248 | read_lock(&resource_lock); | |
249 | for (p = iomem_resource.child; p ; p = p->sibling) { | |
250 | /* system ram is just marked as IORESOURCE_MEM */ | |
251 | if (p->flags != res->flags) | |
252 | continue; | |
253 | if (p->start > end) { | |
254 | p = NULL; | |
255 | break; | |
256 | } | |
257 | if (p->start >= start) | |
258 | break; | |
259 | } | |
260 | read_unlock(&resource_lock); | |
261 | if (!p) | |
262 | return -1; | |
263 | /* copy data */ | |
264 | res->start = p->start; | |
265 | res->end = p->end; | |
266 | return 0; | |
267 | } | |
268 | #endif | |
269 | ||
1da177e4 LT |
270 | /* |
271 | * Find empty slot in the resource tree given range and alignment. | |
272 | */ | |
273 | static int find_resource(struct resource *root, struct resource *new, | |
d75fc8bb GKH |
274 | resource_size_t size, resource_size_t min, |
275 | resource_size_t max, resource_size_t align, | |
1da177e4 | 276 | void (*alignf)(void *, struct resource *, |
d75fc8bb | 277 | resource_size_t, resource_size_t), |
1da177e4 LT |
278 | void *alignf_data) |
279 | { | |
280 | struct resource *this = root->child; | |
281 | ||
282 | new->start = root->start; | |
283 | /* | |
284 | * Skip past an allocated resource that starts at 0, since the assignment | |
285 | * of this->start - 1 to new->end below would cause an underflow. | |
286 | */ | |
287 | if (this && this->start == 0) { | |
288 | new->start = this->end + 1; | |
289 | this = this->sibling; | |
290 | } | |
291 | for(;;) { | |
292 | if (this) | |
293 | new->end = this->start - 1; | |
294 | else | |
295 | new->end = root->end; | |
296 | if (new->start < min) | |
297 | new->start = min; | |
298 | if (new->end > max) | |
299 | new->end = max; | |
8c0e33c1 | 300 | new->start = ALIGN(new->start, align); |
1da177e4 LT |
301 | if (alignf) |
302 | alignf(alignf_data, new, size, align); | |
b52402c7 | 303 | if (new->start < new->end && new->end - new->start >= size - 1) { |
1da177e4 LT |
304 | new->end = new->start + size - 1; |
305 | return 0; | |
306 | } | |
307 | if (!this) | |
308 | break; | |
309 | new->start = this->end + 1; | |
310 | this = this->sibling; | |
311 | } | |
312 | return -EBUSY; | |
313 | } | |
314 | ||
315 | /* | |
316 | * Allocate empty slot in the resource tree given range and alignment. | |
317 | */ | |
318 | int allocate_resource(struct resource *root, struct resource *new, | |
d75fc8bb GKH |
319 | resource_size_t size, resource_size_t min, |
320 | resource_size_t max, resource_size_t align, | |
1da177e4 | 321 | void (*alignf)(void *, struct resource *, |
d75fc8bb | 322 | resource_size_t, resource_size_t), |
1da177e4 LT |
323 | void *alignf_data) |
324 | { | |
325 | int err; | |
326 | ||
327 | write_lock(&resource_lock); | |
328 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); | |
329 | if (err >= 0 && __request_resource(root, new)) | |
330 | err = -EBUSY; | |
331 | write_unlock(&resource_lock); | |
332 | return err; | |
333 | } | |
334 | ||
335 | EXPORT_SYMBOL(allocate_resource); | |
336 | ||
337 | /** | |
338 | * insert_resource - Inserts a resource in the resource tree | |
339 | * @parent: parent of the new resource | |
340 | * @new: new resource to insert | |
341 | * | |
342 | * Returns 0 on success, -EBUSY if the resource can't be inserted. | |
343 | * | |
344 | * This function is equivalent of request_resource when no conflict | |
345 | * happens. If a conflict happens, and the conflicting resources | |
346 | * entirely fit within the range of the new resource, then the new | |
347 | * resource is inserted and the conflicting resources become childs of | |
348 | * the new resource. Otherwise the new resource becomes the child of | |
349 | * the conflicting resource | |
350 | */ | |
351 | int insert_resource(struct resource *parent, struct resource *new) | |
352 | { | |
353 | int result; | |
354 | struct resource *first, *next; | |
355 | ||
356 | write_lock(&resource_lock); | |
357 | begin: | |
358 | result = 0; | |
359 | first = __request_resource(parent, new); | |
360 | if (!first) | |
361 | goto out; | |
362 | ||
363 | result = -EBUSY; | |
364 | if (first == parent) | |
365 | goto out; | |
366 | ||
367 | /* Resource fully contained by the clashing resource? Recurse into it */ | |
368 | if (first->start <= new->start && first->end >= new->end) { | |
369 | parent = first; | |
370 | goto begin; | |
371 | } | |
372 | ||
373 | for (next = first; ; next = next->sibling) { | |
374 | /* Partial overlap? Bad, and unfixable */ | |
375 | if (next->start < new->start || next->end > new->end) | |
376 | goto out; | |
377 | if (!next->sibling) | |
378 | break; | |
379 | if (next->sibling->start > new->end) | |
380 | break; | |
381 | } | |
382 | ||
383 | result = 0; | |
384 | ||
385 | new->parent = parent; | |
386 | new->sibling = next->sibling; | |
387 | new->child = first; | |
388 | ||
389 | next->sibling = NULL; | |
390 | for (next = first; next; next = next->sibling) | |
391 | next->parent = new; | |
392 | ||
393 | if (parent->child == first) { | |
394 | parent->child = new; | |
395 | } else { | |
396 | next = parent->child; | |
397 | while (next->sibling != first) | |
398 | next = next->sibling; | |
399 | next->sibling = new; | |
400 | } | |
401 | ||
402 | out: | |
403 | write_unlock(&resource_lock); | |
404 | return result; | |
405 | } | |
406 | ||
1da177e4 LT |
407 | /* |
408 | * Given an existing resource, change its start and size to match the | |
409 | * arguments. Returns -EBUSY if it can't fit. Existing children of | |
410 | * the resource are assumed to be immutable. | |
411 | */ | |
d75fc8bb | 412 | int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) |
1da177e4 LT |
413 | { |
414 | struct resource *tmp, *parent = res->parent; | |
d75fc8bb | 415 | resource_size_t end = start + size - 1; |
1da177e4 LT |
416 | int result = -EBUSY; |
417 | ||
418 | write_lock(&resource_lock); | |
419 | ||
420 | if ((start < parent->start) || (end > parent->end)) | |
421 | goto out; | |
422 | ||
423 | for (tmp = res->child; tmp; tmp = tmp->sibling) { | |
424 | if ((tmp->start < start) || (tmp->end > end)) | |
425 | goto out; | |
426 | } | |
427 | ||
428 | if (res->sibling && (res->sibling->start <= end)) | |
429 | goto out; | |
430 | ||
431 | tmp = parent->child; | |
432 | if (tmp != res) { | |
433 | while (tmp->sibling != res) | |
434 | tmp = tmp->sibling; | |
435 | if (start <= tmp->end) | |
436 | goto out; | |
437 | } | |
438 | ||
439 | res->start = start; | |
440 | res->end = end; | |
441 | result = 0; | |
442 | ||
443 | out: | |
444 | write_unlock(&resource_lock); | |
445 | return result; | |
446 | } | |
447 | ||
448 | EXPORT_SYMBOL(adjust_resource); | |
449 | ||
450 | /* | |
451 | * This is compatibility stuff for IO resources. | |
452 | * | |
453 | * Note how this, unlike the above, knows about | |
454 | * the IO flag meanings (busy etc). | |
455 | * | |
456 | * Request-region creates a new busy region. | |
457 | * | |
458 | * Check-region returns non-zero if the area is already busy | |
459 | * | |
460 | * Release-region releases a matching busy region. | |
461 | */ | |
d75fc8bb GKH |
462 | struct resource * __request_region(struct resource *parent, |
463 | resource_size_t start, resource_size_t n, | |
464 | const char *name) | |
1da177e4 | 465 | { |
dd392710 | 466 | struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); |
1da177e4 LT |
467 | |
468 | if (res) { | |
1da177e4 LT |
469 | res->name = name; |
470 | res->start = start; | |
471 | res->end = start + n - 1; | |
472 | res->flags = IORESOURCE_BUSY; | |
473 | ||
474 | write_lock(&resource_lock); | |
475 | ||
476 | for (;;) { | |
477 | struct resource *conflict; | |
478 | ||
479 | conflict = __request_resource(parent, res); | |
480 | if (!conflict) | |
481 | break; | |
482 | if (conflict != parent) { | |
483 | parent = conflict; | |
484 | if (!(conflict->flags & IORESOURCE_BUSY)) | |
485 | continue; | |
486 | } | |
487 | ||
488 | /* Uhhuh, that didn't work out.. */ | |
489 | kfree(res); | |
490 | res = NULL; | |
491 | break; | |
492 | } | |
493 | write_unlock(&resource_lock); | |
494 | } | |
495 | return res; | |
496 | } | |
497 | ||
498 | EXPORT_SYMBOL(__request_region); | |
499 | ||
d75fc8bb GKH |
500 | int __check_region(struct resource *parent, resource_size_t start, |
501 | resource_size_t n) | |
1da177e4 LT |
502 | { |
503 | struct resource * res; | |
504 | ||
505 | res = __request_region(parent, start, n, "check-region"); | |
506 | if (!res) | |
507 | return -EBUSY; | |
508 | ||
509 | release_resource(res); | |
510 | kfree(res); | |
511 | return 0; | |
512 | } | |
513 | ||
514 | EXPORT_SYMBOL(__check_region); | |
515 | ||
d75fc8bb GKH |
516 | void __release_region(struct resource *parent, resource_size_t start, |
517 | resource_size_t n) | |
1da177e4 LT |
518 | { |
519 | struct resource **p; | |
d75fc8bb | 520 | resource_size_t end; |
1da177e4 LT |
521 | |
522 | p = &parent->child; | |
523 | end = start + n - 1; | |
524 | ||
525 | write_lock(&resource_lock); | |
526 | ||
527 | for (;;) { | |
528 | struct resource *res = *p; | |
529 | ||
530 | if (!res) | |
531 | break; | |
532 | if (res->start <= start && res->end >= end) { | |
533 | if (!(res->flags & IORESOURCE_BUSY)) { | |
534 | p = &res->child; | |
535 | continue; | |
536 | } | |
537 | if (res->start != start || res->end != end) | |
538 | break; | |
539 | *p = res->sibling; | |
540 | write_unlock(&resource_lock); | |
541 | kfree(res); | |
542 | return; | |
543 | } | |
544 | p = &res->sibling; | |
545 | } | |
546 | ||
547 | write_unlock(&resource_lock); | |
548 | ||
685143ac GKH |
549 | printk(KERN_WARNING "Trying to free nonexistent resource " |
550 | "<%016llx-%016llx>\n", (unsigned long long)start, | |
551 | (unsigned long long)end); | |
1da177e4 LT |
552 | } |
553 | ||
554 | EXPORT_SYMBOL(__release_region); | |
555 | ||
556 | /* | |
557 | * Called from init/main.c to reserve IO ports. | |
558 | */ | |
559 | #define MAXRESERVE 4 | |
560 | static int __init reserve_setup(char *str) | |
561 | { | |
562 | static int reserved; | |
563 | static struct resource reserve[MAXRESERVE]; | |
564 | ||
565 | for (;;) { | |
566 | int io_start, io_num; | |
567 | int x = reserved; | |
568 | ||
569 | if (get_option (&str, &io_start) != 2) | |
570 | break; | |
571 | if (get_option (&str, &io_num) == 0) | |
572 | break; | |
573 | if (x < MAXRESERVE) { | |
574 | struct resource *res = reserve + x; | |
575 | res->name = "reserved"; | |
576 | res->start = io_start; | |
577 | res->end = io_start + io_num - 1; | |
578 | res->flags = IORESOURCE_BUSY; | |
579 | res->child = NULL; | |
580 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) | |
581 | reserved = x+1; | |
582 | } | |
583 | } | |
584 | return 1; | |
585 | } | |
586 | ||
587 | __setup("reserve=", reserve_setup); |