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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/sched.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <linux/device.h> | |
21 | #include <linux/pfn.h> | |
22 | #include <asm/io.h> | |
23 | ||
24 | ||
25 | struct resource ioport_resource = { | |
26 | .name = "PCI IO", | |
27 | .start = 0, | |
28 | .end = IO_SPACE_LIMIT, | |
29 | .flags = IORESOURCE_IO, | |
30 | }; | |
31 | EXPORT_SYMBOL(ioport_resource); | |
32 | ||
33 | struct resource iomem_resource = { | |
34 | .name = "PCI mem", | |
35 | .start = 0, | |
36 | .end = -1, | |
37 | .flags = IORESOURCE_MEM, | |
38 | }; | |
39 | EXPORT_SYMBOL(iomem_resource); | |
40 | ||
41 | static DEFINE_RWLOCK(resource_lock); | |
42 | ||
43 | /* | |
44 | * By default, we allocate free space bottom-up. The architecture can request | |
45 | * top-down by clearing this flag. The user can override the architecture's | |
46 | * choice with the "resource_alloc_from_bottom" kernel boot option, but that | |
47 | * should only be a debugging tool. | |
48 | */ | |
49 | int resource_alloc_from_bottom = 1; | |
50 | ||
51 | static __init int setup_alloc_from_bottom(char *s) | |
52 | { | |
53 | printk(KERN_INFO | |
54 | "resource: allocating from bottom-up; please report a bug\n"); | |
55 | resource_alloc_from_bottom = 1; | |
56 | return 0; | |
57 | } | |
58 | early_param("resource_alloc_from_bottom", setup_alloc_from_bottom); | |
59 | ||
60 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | |
61 | { | |
62 | struct resource *p = v; | |
63 | (*pos)++; | |
64 | if (p->child) | |
65 | return p->child; | |
66 | while (!p->sibling && p->parent) | |
67 | p = p->parent; | |
68 | return p->sibling; | |
69 | } | |
70 | ||
71 | #ifdef CONFIG_PROC_FS | |
72 | ||
73 | enum { MAX_IORES_LEVEL = 5 }; | |
74 | ||
75 | static void *r_start(struct seq_file *m, loff_t *pos) | |
76 | __acquires(resource_lock) | |
77 | { | |
78 | struct resource *p = m->private; | |
79 | loff_t l = 0; | |
80 | read_lock(&resource_lock); | |
81 | for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) | |
82 | ; | |
83 | return p; | |
84 | } | |
85 | ||
86 | static void r_stop(struct seq_file *m, void *v) | |
87 | __releases(resource_lock) | |
88 | { | |
89 | read_unlock(&resource_lock); | |
90 | } | |
91 | ||
92 | static int r_show(struct seq_file *m, void *v) | |
93 | { | |
94 | struct resource *root = m->private; | |
95 | struct resource *r = v, *p; | |
96 | int width = root->end < 0x10000 ? 4 : 8; | |
97 | int depth; | |
98 | ||
99 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) | |
100 | if (p->parent == root) | |
101 | break; | |
102 | seq_printf(m, "%*s%0*llx-%0*llx : %s\n", | |
103 | depth * 2, "", | |
104 | width, (unsigned long long) r->start, | |
105 | width, (unsigned long long) r->end, | |
106 | r->name ? r->name : "<BAD>"); | |
107 | return 0; | |
108 | } | |
109 | ||
110 | static const struct seq_operations resource_op = { | |
111 | .start = r_start, | |
112 | .next = r_next, | |
113 | .stop = r_stop, | |
114 | .show = r_show, | |
115 | }; | |
116 | ||
117 | static int ioports_open(struct inode *inode, struct file *file) | |
118 | { | |
119 | int res = seq_open(file, &resource_op); | |
120 | if (!res) { | |
121 | struct seq_file *m = file->private_data; | |
122 | m->private = &ioport_resource; | |
123 | } | |
124 | return res; | |
125 | } | |
126 | ||
127 | static int iomem_open(struct inode *inode, struct file *file) | |
128 | { | |
129 | int res = seq_open(file, &resource_op); | |
130 | if (!res) { | |
131 | struct seq_file *m = file->private_data; | |
132 | m->private = &iomem_resource; | |
133 | } | |
134 | return res; | |
135 | } | |
136 | ||
137 | static const struct file_operations proc_ioports_operations = { | |
138 | .open = ioports_open, | |
139 | .read = seq_read, | |
140 | .llseek = seq_lseek, | |
141 | .release = seq_release, | |
142 | }; | |
143 | ||
144 | static const struct file_operations proc_iomem_operations = { | |
145 | .open = iomem_open, | |
146 | .read = seq_read, | |
147 | .llseek = seq_lseek, | |
148 | .release = seq_release, | |
149 | }; | |
150 | ||
151 | static int __init ioresources_init(void) | |
152 | { | |
153 | proc_create("ioports", 0, NULL, &proc_ioports_operations); | |
154 | proc_create("iomem", 0, NULL, &proc_iomem_operations); | |
155 | return 0; | |
156 | } | |
157 | __initcall(ioresources_init); | |
158 | ||
159 | #endif /* CONFIG_PROC_FS */ | |
160 | ||
161 | /* Return the conflict entry if you can't request it */ | |
162 | static struct resource * __request_resource(struct resource *root, struct resource *new) | |
163 | { | |
164 | resource_size_t start = new->start; | |
165 | resource_size_t end = new->end; | |
166 | struct resource *tmp, **p; | |
167 | ||
168 | if (end < start) | |
169 | return root; | |
170 | if (start < root->start) | |
171 | return root; | |
172 | if (end > root->end) | |
173 | return root; | |
174 | p = &root->child; | |
175 | for (;;) { | |
176 | tmp = *p; | |
177 | if (!tmp || tmp->start > end) { | |
178 | new->sibling = tmp; | |
179 | *p = new; | |
180 | new->parent = root; | |
181 | return NULL; | |
182 | } | |
183 | p = &tmp->sibling; | |
184 | if (tmp->end < start) | |
185 | continue; | |
186 | return tmp; | |
187 | } | |
188 | } | |
189 | ||
190 | static int __release_resource(struct resource *old) | |
191 | { | |
192 | struct resource *tmp, **p; | |
193 | ||
194 | p = &old->parent->child; | |
195 | for (;;) { | |
196 | tmp = *p; | |
197 | if (!tmp) | |
198 | break; | |
199 | if (tmp == old) { | |
200 | *p = tmp->sibling; | |
201 | old->parent = NULL; | |
202 | return 0; | |
203 | } | |
204 | p = &tmp->sibling; | |
205 | } | |
206 | return -EINVAL; | |
207 | } | |
208 | ||
209 | static void __release_child_resources(struct resource *r) | |
210 | { | |
211 | struct resource *tmp, *p; | |
212 | resource_size_t size; | |
213 | ||
214 | p = r->child; | |
215 | r->child = NULL; | |
216 | while (p) { | |
217 | tmp = p; | |
218 | p = p->sibling; | |
219 | ||
220 | tmp->parent = NULL; | |
221 | tmp->sibling = NULL; | |
222 | __release_child_resources(tmp); | |
223 | ||
224 | printk(KERN_DEBUG "release child resource %pR\n", tmp); | |
225 | /* need to restore size, and keep flags */ | |
226 | size = resource_size(tmp); | |
227 | tmp->start = 0; | |
228 | tmp->end = size - 1; | |
229 | } | |
230 | } | |
231 | ||
232 | void release_child_resources(struct resource *r) | |
233 | { | |
234 | write_lock(&resource_lock); | |
235 | __release_child_resources(r); | |
236 | write_unlock(&resource_lock); | |
237 | } | |
238 | ||
239 | /** | |
240 | * request_resource_conflict - request and reserve an I/O or memory resource | |
241 | * @root: root resource descriptor | |
242 | * @new: resource descriptor desired by caller | |
243 | * | |
244 | * Returns 0 for success, conflict resource on error. | |
245 | */ | |
246 | struct resource *request_resource_conflict(struct resource *root, struct resource *new) | |
247 | { | |
248 | struct resource *conflict; | |
249 | ||
250 | write_lock(&resource_lock); | |
251 | conflict = __request_resource(root, new); | |
252 | write_unlock(&resource_lock); | |
253 | return conflict; | |
254 | } | |
255 | ||
256 | /** | |
257 | * request_resource - request and reserve an I/O or memory resource | |
258 | * @root: root resource descriptor | |
259 | * @new: resource descriptor desired by caller | |
260 | * | |
261 | * Returns 0 for success, negative error code on error. | |
262 | */ | |
263 | int request_resource(struct resource *root, struct resource *new) | |
264 | { | |
265 | struct resource *conflict; | |
266 | ||
267 | conflict = request_resource_conflict(root, new); | |
268 | return conflict ? -EBUSY : 0; | |
269 | } | |
270 | ||
271 | EXPORT_SYMBOL(request_resource); | |
272 | ||
273 | /** | |
274 | * release_resource - release a previously reserved resource | |
275 | * @old: resource pointer | |
276 | */ | |
277 | int release_resource(struct resource *old) | |
278 | { | |
279 | int retval; | |
280 | ||
281 | write_lock(&resource_lock); | |
282 | retval = __release_resource(old); | |
283 | write_unlock(&resource_lock); | |
284 | return retval; | |
285 | } | |
286 | ||
287 | EXPORT_SYMBOL(release_resource); | |
288 | ||
289 | #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) | |
290 | /* | |
291 | * Finds the lowest memory reosurce exists within [res->start.res->end) | |
292 | * the caller must specify res->start, res->end, res->flags and "name". | |
293 | * If found, returns 0, res is overwritten, if not found, returns -1. | |
294 | */ | |
295 | static int find_next_system_ram(struct resource *res, char *name) | |
296 | { | |
297 | resource_size_t start, end; | |
298 | struct resource *p; | |
299 | ||
300 | BUG_ON(!res); | |
301 | ||
302 | start = res->start; | |
303 | end = res->end; | |
304 | BUG_ON(start >= end); | |
305 | ||
306 | read_lock(&resource_lock); | |
307 | for (p = iomem_resource.child; p ; p = p->sibling) { | |
308 | /* system ram is just marked as IORESOURCE_MEM */ | |
309 | if (p->flags != res->flags) | |
310 | continue; | |
311 | if (name && strcmp(p->name, name)) | |
312 | continue; | |
313 | if (p->start > end) { | |
314 | p = NULL; | |
315 | break; | |
316 | } | |
317 | if ((p->end >= start) && (p->start < end)) | |
318 | break; | |
319 | } | |
320 | read_unlock(&resource_lock); | |
321 | if (!p) | |
322 | return -1; | |
323 | /* copy data */ | |
324 | if (res->start < p->start) | |
325 | res->start = p->start; | |
326 | if (res->end > p->end) | |
327 | res->end = p->end; | |
328 | return 0; | |
329 | } | |
330 | ||
331 | /* | |
332 | * This function calls callback against all memory range of "System RAM" | |
333 | * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. | |
334 | * Now, this function is only for "System RAM". | |
335 | */ | |
336 | int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, | |
337 | void *arg, int (*func)(unsigned long, unsigned long, void *)) | |
338 | { | |
339 | struct resource res; | |
340 | unsigned long pfn, end_pfn; | |
341 | u64 orig_end; | |
342 | int ret = -1; | |
343 | ||
344 | res.start = (u64) start_pfn << PAGE_SHIFT; | |
345 | res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; | |
346 | res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; | |
347 | orig_end = res.end; | |
348 | while ((res.start < res.end) && | |
349 | (find_next_system_ram(&res, "System RAM") >= 0)) { | |
350 | pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
351 | end_pfn = (res.end + 1) >> PAGE_SHIFT; | |
352 | if (end_pfn > pfn) | |
353 | ret = (*func)(pfn, end_pfn - pfn, arg); | |
354 | if (ret) | |
355 | break; | |
356 | res.start = res.end + 1; | |
357 | res.end = orig_end; | |
358 | } | |
359 | return ret; | |
360 | } | |
361 | ||
362 | #endif | |
363 | ||
364 | static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) | |
365 | { | |
366 | return 1; | |
367 | } | |
368 | /* | |
369 | * This generic page_is_ram() returns true if specified address is | |
370 | * registered as "System RAM" in iomem_resource list. | |
371 | */ | |
372 | int __weak page_is_ram(unsigned long pfn) | |
373 | { | |
374 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; | |
375 | } | |
376 | ||
377 | static resource_size_t simple_align_resource(void *data, | |
378 | const struct resource *avail, | |
379 | resource_size_t size, | |
380 | resource_size_t align) | |
381 | { | |
382 | return avail->start; | |
383 | } | |
384 | ||
385 | static void resource_clip(struct resource *res, resource_size_t min, | |
386 | resource_size_t max) | |
387 | { | |
388 | if (res->start < min) | |
389 | res->start = min; | |
390 | if (res->end > max) | |
391 | res->end = max; | |
392 | } | |
393 | ||
394 | static bool resource_contains(struct resource *res1, struct resource *res2) | |
395 | { | |
396 | return res1->start <= res2->start && res1->end >= res2->end; | |
397 | } | |
398 | ||
399 | /* | |
400 | * Find the resource before "child" in the sibling list of "root" children. | |
401 | */ | |
402 | static struct resource *find_sibling_prev(struct resource *root, struct resource *child) | |
403 | { | |
404 | struct resource *this; | |
405 | ||
406 | for (this = root->child; this; this = this->sibling) | |
407 | if (this->sibling == child) | |
408 | return this; | |
409 | ||
410 | return NULL; | |
411 | } | |
412 | ||
413 | /* | |
414 | * Find empty slot in the resource tree given range and alignment. | |
415 | * This version allocates from the end of the root resource first. | |
416 | */ | |
417 | static int find_resource_from_top(struct resource *root, struct resource *new, | |
418 | resource_size_t size, resource_size_t min, | |
419 | resource_size_t max, resource_size_t align, | |
420 | resource_size_t (*alignf)(void *, | |
421 | const struct resource *, | |
422 | resource_size_t, | |
423 | resource_size_t), | |
424 | void *alignf_data) | |
425 | { | |
426 | struct resource *this; | |
427 | struct resource tmp, avail, alloc; | |
428 | ||
429 | tmp.start = root->end; | |
430 | tmp.end = root->end; | |
431 | ||
432 | this = find_sibling_prev(root, NULL); | |
433 | for (;;) { | |
434 | if (this) { | |
435 | if (this->end < root->end) | |
436 | tmp.start = this->end + 1; | |
437 | } else | |
438 | tmp.start = root->start; | |
439 | ||
440 | resource_clip(&tmp, min, max); | |
441 | ||
442 | /* Check for overflow after ALIGN() */ | |
443 | avail = *new; | |
444 | avail.start = ALIGN(tmp.start, align); | |
445 | avail.end = tmp.end; | |
446 | if (avail.start >= tmp.start) { | |
447 | alloc.start = alignf(alignf_data, &avail, size, align); | |
448 | alloc.end = alloc.start + size - 1; | |
449 | if (resource_contains(&avail, &alloc)) { | |
450 | new->start = alloc.start; | |
451 | new->end = alloc.end; | |
452 | return 0; | |
453 | } | |
454 | } | |
455 | ||
456 | if (!this || this->start == root->start) | |
457 | break; | |
458 | ||
459 | tmp.end = this->start - 1; | |
460 | this = find_sibling_prev(root, this); | |
461 | } | |
462 | return -EBUSY; | |
463 | } | |
464 | ||
465 | /* | |
466 | * Find empty slot in the resource tree given range and alignment. | |
467 | * This version allocates from the beginning of the root resource first. | |
468 | */ | |
469 | static int find_resource(struct resource *root, struct resource *new, | |
470 | resource_size_t size, resource_size_t min, | |
471 | resource_size_t max, resource_size_t align, | |
472 | resource_size_t (*alignf)(void *, | |
473 | const struct resource *, | |
474 | resource_size_t, | |
475 | resource_size_t), | |
476 | void *alignf_data) | |
477 | { | |
478 | struct resource *this = root->child; | |
479 | struct resource tmp = *new, avail, alloc; | |
480 | ||
481 | tmp.start = root->start; | |
482 | /* | |
483 | * Skip past an allocated resource that starts at 0, since the | |
484 | * assignment of this->start - 1 to tmp->end below would cause an | |
485 | * underflow. | |
486 | */ | |
487 | if (this && this->start == 0) { | |
488 | tmp.start = this->end + 1; | |
489 | this = this->sibling; | |
490 | } | |
491 | for (;;) { | |
492 | if (this) | |
493 | tmp.end = this->start - 1; | |
494 | else | |
495 | tmp.end = root->end; | |
496 | ||
497 | resource_clip(&tmp, min, max); | |
498 | ||
499 | /* Check for overflow after ALIGN() */ | |
500 | avail = *new; | |
501 | avail.start = ALIGN(tmp.start, align); | |
502 | avail.end = tmp.end; | |
503 | if (avail.start >= tmp.start) { | |
504 | alloc.start = alignf(alignf_data, &avail, size, align); | |
505 | alloc.end = alloc.start + size - 1; | |
506 | if (resource_contains(&avail, &alloc)) { | |
507 | new->start = alloc.start; | |
508 | new->end = alloc.end; | |
509 | return 0; | |
510 | } | |
511 | } | |
512 | ||
513 | if (!this) | |
514 | break; | |
515 | ||
516 | tmp.start = this->end + 1; | |
517 | this = this->sibling; | |
518 | } | |
519 | return -EBUSY; | |
520 | } | |
521 | ||
522 | /** | |
523 | * allocate_resource - allocate empty slot in the resource tree given range & alignment | |
524 | * @root: root resource descriptor | |
525 | * @new: resource descriptor desired by caller | |
526 | * @size: requested resource region size | |
527 | * @min: minimum size to allocate | |
528 | * @max: maximum size to allocate | |
529 | * @align: alignment requested, in bytes | |
530 | * @alignf: alignment function, optional, called if not NULL | |
531 | * @alignf_data: arbitrary data to pass to the @alignf function | |
532 | */ | |
533 | int allocate_resource(struct resource *root, struct resource *new, | |
534 | resource_size_t size, resource_size_t min, | |
535 | resource_size_t max, resource_size_t align, | |
536 | resource_size_t (*alignf)(void *, | |
537 | const struct resource *, | |
538 | resource_size_t, | |
539 | resource_size_t), | |
540 | void *alignf_data) | |
541 | { | |
542 | int err; | |
543 | ||
544 | if (!alignf) | |
545 | alignf = simple_align_resource; | |
546 | ||
547 | write_lock(&resource_lock); | |
548 | if (resource_alloc_from_bottom) | |
549 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); | |
550 | else | |
551 | err = find_resource_from_top(root, new, size, min, max, align, alignf, alignf_data); | |
552 | if (err >= 0 && __request_resource(root, new)) | |
553 | err = -EBUSY; | |
554 | write_unlock(&resource_lock); | |
555 | return err; | |
556 | } | |
557 | ||
558 | EXPORT_SYMBOL(allocate_resource); | |
559 | ||
560 | /* | |
561 | * Insert a resource into the resource tree. If successful, return NULL, | |
562 | * otherwise return the conflicting resource (compare to __request_resource()) | |
563 | */ | |
564 | static struct resource * __insert_resource(struct resource *parent, struct resource *new) | |
565 | { | |
566 | struct resource *first, *next; | |
567 | ||
568 | for (;; parent = first) { | |
569 | first = __request_resource(parent, new); | |
570 | if (!first) | |
571 | return first; | |
572 | ||
573 | if (first == parent) | |
574 | return first; | |
575 | if (WARN_ON(first == new)) /* duplicated insertion */ | |
576 | return first; | |
577 | ||
578 | if ((first->start > new->start) || (first->end < new->end)) | |
579 | break; | |
580 | if ((first->start == new->start) && (first->end == new->end)) | |
581 | break; | |
582 | } | |
583 | ||
584 | for (next = first; ; next = next->sibling) { | |
585 | /* Partial overlap? Bad, and unfixable */ | |
586 | if (next->start < new->start || next->end > new->end) | |
587 | return next; | |
588 | if (!next->sibling) | |
589 | break; | |
590 | if (next->sibling->start > new->end) | |
591 | break; | |
592 | } | |
593 | ||
594 | new->parent = parent; | |
595 | new->sibling = next->sibling; | |
596 | new->child = first; | |
597 | ||
598 | next->sibling = NULL; | |
599 | for (next = first; next; next = next->sibling) | |
600 | next->parent = new; | |
601 | ||
602 | if (parent->child == first) { | |
603 | parent->child = new; | |
604 | } else { | |
605 | next = parent->child; | |
606 | while (next->sibling != first) | |
607 | next = next->sibling; | |
608 | next->sibling = new; | |
609 | } | |
610 | return NULL; | |
611 | } | |
612 | ||
613 | /** | |
614 | * insert_resource_conflict - Inserts resource in the resource tree | |
615 | * @parent: parent of the new resource | |
616 | * @new: new resource to insert | |
617 | * | |
618 | * Returns 0 on success, conflict resource if the resource can't be inserted. | |
619 | * | |
620 | * This function is equivalent to request_resource_conflict when no conflict | |
621 | * happens. If a conflict happens, and the conflicting resources | |
622 | * entirely fit within the range of the new resource, then the new | |
623 | * resource is inserted and the conflicting resources become children of | |
624 | * the new resource. | |
625 | */ | |
626 | struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) | |
627 | { | |
628 | struct resource *conflict; | |
629 | ||
630 | write_lock(&resource_lock); | |
631 | conflict = __insert_resource(parent, new); | |
632 | write_unlock(&resource_lock); | |
633 | return conflict; | |
634 | } | |
635 | ||
636 | /** | |
637 | * insert_resource - Inserts a resource in the resource tree | |
638 | * @parent: parent of the new resource | |
639 | * @new: new resource to insert | |
640 | * | |
641 | * Returns 0 on success, -EBUSY if the resource can't be inserted. | |
642 | */ | |
643 | int insert_resource(struct resource *parent, struct resource *new) | |
644 | { | |
645 | struct resource *conflict; | |
646 | ||
647 | conflict = insert_resource_conflict(parent, new); | |
648 | return conflict ? -EBUSY : 0; | |
649 | } | |
650 | ||
651 | /** | |
652 | * insert_resource_expand_to_fit - Insert a resource into the resource tree | |
653 | * @root: root resource descriptor | |
654 | * @new: new resource to insert | |
655 | * | |
656 | * Insert a resource into the resource tree, possibly expanding it in order | |
657 | * to make it encompass any conflicting resources. | |
658 | */ | |
659 | void insert_resource_expand_to_fit(struct resource *root, struct resource *new) | |
660 | { | |
661 | if (new->parent) | |
662 | return; | |
663 | ||
664 | write_lock(&resource_lock); | |
665 | for (;;) { | |
666 | struct resource *conflict; | |
667 | ||
668 | conflict = __insert_resource(root, new); | |
669 | if (!conflict) | |
670 | break; | |
671 | if (conflict == root) | |
672 | break; | |
673 | ||
674 | /* Ok, expand resource to cover the conflict, then try again .. */ | |
675 | if (conflict->start < new->start) | |
676 | new->start = conflict->start; | |
677 | if (conflict->end > new->end) | |
678 | new->end = conflict->end; | |
679 | ||
680 | printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); | |
681 | } | |
682 | write_unlock(&resource_lock); | |
683 | } | |
684 | ||
685 | /** | |
686 | * adjust_resource - modify a resource's start and size | |
687 | * @res: resource to modify | |
688 | * @start: new start value | |
689 | * @size: new size | |
690 | * | |
691 | * Given an existing resource, change its start and size to match the | |
692 | * arguments. Returns 0 on success, -EBUSY if it can't fit. | |
693 | * Existing children of the resource are assumed to be immutable. | |
694 | */ | |
695 | int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) | |
696 | { | |
697 | struct resource *tmp, *parent = res->parent; | |
698 | resource_size_t end = start + size - 1; | |
699 | int result = -EBUSY; | |
700 | ||
701 | write_lock(&resource_lock); | |
702 | ||
703 | if ((start < parent->start) || (end > parent->end)) | |
704 | goto out; | |
705 | ||
706 | for (tmp = res->child; tmp; tmp = tmp->sibling) { | |
707 | if ((tmp->start < start) || (tmp->end > end)) | |
708 | goto out; | |
709 | } | |
710 | ||
711 | if (res->sibling && (res->sibling->start <= end)) | |
712 | goto out; | |
713 | ||
714 | tmp = parent->child; | |
715 | if (tmp != res) { | |
716 | while (tmp->sibling != res) | |
717 | tmp = tmp->sibling; | |
718 | if (start <= tmp->end) | |
719 | goto out; | |
720 | } | |
721 | ||
722 | res->start = start; | |
723 | res->end = end; | |
724 | result = 0; | |
725 | ||
726 | out: | |
727 | write_unlock(&resource_lock); | |
728 | return result; | |
729 | } | |
730 | ||
731 | static void __init __reserve_region_with_split(struct resource *root, | |
732 | resource_size_t start, resource_size_t end, | |
733 | const char *name) | |
734 | { | |
735 | struct resource *parent = root; | |
736 | struct resource *conflict; | |
737 | struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); | |
738 | ||
739 | if (!res) | |
740 | return; | |
741 | ||
742 | res->name = name; | |
743 | res->start = start; | |
744 | res->end = end; | |
745 | res->flags = IORESOURCE_BUSY; | |
746 | ||
747 | conflict = __request_resource(parent, res); | |
748 | if (!conflict) | |
749 | return; | |
750 | ||
751 | /* failed, split and try again */ | |
752 | kfree(res); | |
753 | ||
754 | /* conflict covered whole area */ | |
755 | if (conflict->start <= start && conflict->end >= end) | |
756 | return; | |
757 | ||
758 | if (conflict->start > start) | |
759 | __reserve_region_with_split(root, start, conflict->start-1, name); | |
760 | if (conflict->end < end) | |
761 | __reserve_region_with_split(root, conflict->end+1, end, name); | |
762 | } | |
763 | ||
764 | void __init reserve_region_with_split(struct resource *root, | |
765 | resource_size_t start, resource_size_t end, | |
766 | const char *name) | |
767 | { | |
768 | write_lock(&resource_lock); | |
769 | __reserve_region_with_split(root, start, end, name); | |
770 | write_unlock(&resource_lock); | |
771 | } | |
772 | ||
773 | EXPORT_SYMBOL(adjust_resource); | |
774 | ||
775 | /** | |
776 | * resource_alignment - calculate resource's alignment | |
777 | * @res: resource pointer | |
778 | * | |
779 | * Returns alignment on success, 0 (invalid alignment) on failure. | |
780 | */ | |
781 | resource_size_t resource_alignment(struct resource *res) | |
782 | { | |
783 | switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { | |
784 | case IORESOURCE_SIZEALIGN: | |
785 | return resource_size(res); | |
786 | case IORESOURCE_STARTALIGN: | |
787 | return res->start; | |
788 | default: | |
789 | return 0; | |
790 | } | |
791 | } | |
792 | ||
793 | /* | |
794 | * This is compatibility stuff for IO resources. | |
795 | * | |
796 | * Note how this, unlike the above, knows about | |
797 | * the IO flag meanings (busy etc). | |
798 | * | |
799 | * request_region creates a new busy region. | |
800 | * | |
801 | * check_region returns non-zero if the area is already busy. | |
802 | * | |
803 | * release_region releases a matching busy region. | |
804 | */ | |
805 | ||
806 | static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); | |
807 | ||
808 | /** | |
809 | * __request_region - create a new busy resource region | |
810 | * @parent: parent resource descriptor | |
811 | * @start: resource start address | |
812 | * @n: resource region size | |
813 | * @name: reserving caller's ID string | |
814 | * @flags: IO resource flags | |
815 | */ | |
816 | struct resource * __request_region(struct resource *parent, | |
817 | resource_size_t start, resource_size_t n, | |
818 | const char *name, int flags) | |
819 | { | |
820 | DECLARE_WAITQUEUE(wait, current); | |
821 | struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); | |
822 | ||
823 | if (!res) | |
824 | return NULL; | |
825 | ||
826 | res->name = name; | |
827 | res->start = start; | |
828 | res->end = start + n - 1; | |
829 | res->flags = IORESOURCE_BUSY; | |
830 | res->flags |= flags; | |
831 | ||
832 | write_lock(&resource_lock); | |
833 | ||
834 | for (;;) { | |
835 | struct resource *conflict; | |
836 | ||
837 | conflict = __request_resource(parent, res); | |
838 | if (!conflict) | |
839 | break; | |
840 | if (conflict != parent) { | |
841 | parent = conflict; | |
842 | if (!(conflict->flags & IORESOURCE_BUSY)) | |
843 | continue; | |
844 | } | |
845 | if (conflict->flags & flags & IORESOURCE_MUXED) { | |
846 | add_wait_queue(&muxed_resource_wait, &wait); | |
847 | write_unlock(&resource_lock); | |
848 | set_current_state(TASK_UNINTERRUPTIBLE); | |
849 | schedule(); | |
850 | remove_wait_queue(&muxed_resource_wait, &wait); | |
851 | write_lock(&resource_lock); | |
852 | continue; | |
853 | } | |
854 | /* Uhhuh, that didn't work out.. */ | |
855 | kfree(res); | |
856 | res = NULL; | |
857 | break; | |
858 | } | |
859 | write_unlock(&resource_lock); | |
860 | return res; | |
861 | } | |
862 | EXPORT_SYMBOL(__request_region); | |
863 | ||
864 | /** | |
865 | * __check_region - check if a resource region is busy or free | |
866 | * @parent: parent resource descriptor | |
867 | * @start: resource start address | |
868 | * @n: resource region size | |
869 | * | |
870 | * Returns 0 if the region is free at the moment it is checked, | |
871 | * returns %-EBUSY if the region is busy. | |
872 | * | |
873 | * NOTE: | |
874 | * This function is deprecated because its use is racy. | |
875 | * Even if it returns 0, a subsequent call to request_region() | |
876 | * may fail because another driver etc. just allocated the region. | |
877 | * Do NOT use it. It will be removed from the kernel. | |
878 | */ | |
879 | int __check_region(struct resource *parent, resource_size_t start, | |
880 | resource_size_t n) | |
881 | { | |
882 | struct resource * res; | |
883 | ||
884 | res = __request_region(parent, start, n, "check-region", 0); | |
885 | if (!res) | |
886 | return -EBUSY; | |
887 | ||
888 | release_resource(res); | |
889 | kfree(res); | |
890 | return 0; | |
891 | } | |
892 | EXPORT_SYMBOL(__check_region); | |
893 | ||
894 | /** | |
895 | * __release_region - release a previously reserved resource region | |
896 | * @parent: parent resource descriptor | |
897 | * @start: resource start address | |
898 | * @n: resource region size | |
899 | * | |
900 | * The described resource region must match a currently busy region. | |
901 | */ | |
902 | void __release_region(struct resource *parent, resource_size_t start, | |
903 | resource_size_t n) | |
904 | { | |
905 | struct resource **p; | |
906 | resource_size_t end; | |
907 | ||
908 | p = &parent->child; | |
909 | end = start + n - 1; | |
910 | ||
911 | write_lock(&resource_lock); | |
912 | ||
913 | for (;;) { | |
914 | struct resource *res = *p; | |
915 | ||
916 | if (!res) | |
917 | break; | |
918 | if (res->start <= start && res->end >= end) { | |
919 | if (!(res->flags & IORESOURCE_BUSY)) { | |
920 | p = &res->child; | |
921 | continue; | |
922 | } | |
923 | if (res->start != start || res->end != end) | |
924 | break; | |
925 | *p = res->sibling; | |
926 | write_unlock(&resource_lock); | |
927 | if (res->flags & IORESOURCE_MUXED) | |
928 | wake_up(&muxed_resource_wait); | |
929 | kfree(res); | |
930 | return; | |
931 | } | |
932 | p = &res->sibling; | |
933 | } | |
934 | ||
935 | write_unlock(&resource_lock); | |
936 | ||
937 | printk(KERN_WARNING "Trying to free nonexistent resource " | |
938 | "<%016llx-%016llx>\n", (unsigned long long)start, | |
939 | (unsigned long long)end); | |
940 | } | |
941 | EXPORT_SYMBOL(__release_region); | |
942 | ||
943 | /* | |
944 | * Managed region resource | |
945 | */ | |
946 | struct region_devres { | |
947 | struct resource *parent; | |
948 | resource_size_t start; | |
949 | resource_size_t n; | |
950 | }; | |
951 | ||
952 | static void devm_region_release(struct device *dev, void *res) | |
953 | { | |
954 | struct region_devres *this = res; | |
955 | ||
956 | __release_region(this->parent, this->start, this->n); | |
957 | } | |
958 | ||
959 | static int devm_region_match(struct device *dev, void *res, void *match_data) | |
960 | { | |
961 | struct region_devres *this = res, *match = match_data; | |
962 | ||
963 | return this->parent == match->parent && | |
964 | this->start == match->start && this->n == match->n; | |
965 | } | |
966 | ||
967 | struct resource * __devm_request_region(struct device *dev, | |
968 | struct resource *parent, resource_size_t start, | |
969 | resource_size_t n, const char *name) | |
970 | { | |
971 | struct region_devres *dr = NULL; | |
972 | struct resource *res; | |
973 | ||
974 | dr = devres_alloc(devm_region_release, sizeof(struct region_devres), | |
975 | GFP_KERNEL); | |
976 | if (!dr) | |
977 | return NULL; | |
978 | ||
979 | dr->parent = parent; | |
980 | dr->start = start; | |
981 | dr->n = n; | |
982 | ||
983 | res = __request_region(parent, start, n, name, 0); | |
984 | if (res) | |
985 | devres_add(dev, dr); | |
986 | else | |
987 | devres_free(dr); | |
988 | ||
989 | return res; | |
990 | } | |
991 | EXPORT_SYMBOL(__devm_request_region); | |
992 | ||
993 | void __devm_release_region(struct device *dev, struct resource *parent, | |
994 | resource_size_t start, resource_size_t n) | |
995 | { | |
996 | struct region_devres match_data = { parent, start, n }; | |
997 | ||
998 | __release_region(parent, start, n); | |
999 | WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, | |
1000 | &match_data)); | |
1001 | } | |
1002 | EXPORT_SYMBOL(__devm_release_region); | |
1003 | ||
1004 | /* | |
1005 | * Called from init/main.c to reserve IO ports. | |
1006 | */ | |
1007 | #define MAXRESERVE 4 | |
1008 | static int __init reserve_setup(char *str) | |
1009 | { | |
1010 | static int reserved; | |
1011 | static struct resource reserve[MAXRESERVE]; | |
1012 | ||
1013 | for (;;) { | |
1014 | unsigned int io_start, io_num; | |
1015 | int x = reserved; | |
1016 | ||
1017 | if (get_option (&str, &io_start) != 2) | |
1018 | break; | |
1019 | if (get_option (&str, &io_num) == 0) | |
1020 | break; | |
1021 | if (x < MAXRESERVE) { | |
1022 | struct resource *res = reserve + x; | |
1023 | res->name = "reserved"; | |
1024 | res->start = io_start; | |
1025 | res->end = io_start + io_num - 1; | |
1026 | res->flags = IORESOURCE_BUSY; | |
1027 | res->child = NULL; | |
1028 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) | |
1029 | reserved = x+1; | |
1030 | } | |
1031 | } | |
1032 | return 1; | |
1033 | } | |
1034 | ||
1035 | __setup("reserve=", reserve_setup); | |
1036 | ||
1037 | /* | |
1038 | * Check if the requested addr and size spans more than any slot in the | |
1039 | * iomem resource tree. | |
1040 | */ | |
1041 | int iomem_map_sanity_check(resource_size_t addr, unsigned long size) | |
1042 | { | |
1043 | struct resource *p = &iomem_resource; | |
1044 | int err = 0; | |
1045 | loff_t l; | |
1046 | ||
1047 | read_lock(&resource_lock); | |
1048 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { | |
1049 | /* | |
1050 | * We can probably skip the resources without | |
1051 | * IORESOURCE_IO attribute? | |
1052 | */ | |
1053 | if (p->start >= addr + size) | |
1054 | continue; | |
1055 | if (p->end < addr) | |
1056 | continue; | |
1057 | if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && | |
1058 | PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) | |
1059 | continue; | |
1060 | /* | |
1061 | * if a resource is "BUSY", it's not a hardware resource | |
1062 | * but a driver mapping of such a resource; we don't want | |
1063 | * to warn for those; some drivers legitimately map only | |
1064 | * partial hardware resources. (example: vesafb) | |
1065 | */ | |
1066 | if (p->flags & IORESOURCE_BUSY) | |
1067 | continue; | |
1068 | ||
1069 | printk(KERN_WARNING "resource map sanity check conflict: " | |
1070 | "0x%llx 0x%llx 0x%llx 0x%llx %s\n", | |
1071 | (unsigned long long)addr, | |
1072 | (unsigned long long)(addr + size - 1), | |
1073 | (unsigned long long)p->start, | |
1074 | (unsigned long long)p->end, | |
1075 | p->name); | |
1076 | err = -1; | |
1077 | break; | |
1078 | } | |
1079 | read_unlock(&resource_lock); | |
1080 | ||
1081 | return err; | |
1082 | } | |
1083 | ||
1084 | #ifdef CONFIG_STRICT_DEVMEM | |
1085 | static int strict_iomem_checks = 1; | |
1086 | #else | |
1087 | static int strict_iomem_checks; | |
1088 | #endif | |
1089 | ||
1090 | /* | |
1091 | * check if an address is reserved in the iomem resource tree | |
1092 | * returns 1 if reserved, 0 if not reserved. | |
1093 | */ | |
1094 | int iomem_is_exclusive(u64 addr) | |
1095 | { | |
1096 | struct resource *p = &iomem_resource; | |
1097 | int err = 0; | |
1098 | loff_t l; | |
1099 | int size = PAGE_SIZE; | |
1100 | ||
1101 | if (!strict_iomem_checks) | |
1102 | return 0; | |
1103 | ||
1104 | addr = addr & PAGE_MASK; | |
1105 | ||
1106 | read_lock(&resource_lock); | |
1107 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { | |
1108 | /* | |
1109 | * We can probably skip the resources without | |
1110 | * IORESOURCE_IO attribute? | |
1111 | */ | |
1112 | if (p->start >= addr + size) | |
1113 | break; | |
1114 | if (p->end < addr) | |
1115 | continue; | |
1116 | if (p->flags & IORESOURCE_BUSY && | |
1117 | p->flags & IORESOURCE_EXCLUSIVE) { | |
1118 | err = 1; | |
1119 | break; | |
1120 | } | |
1121 | } | |
1122 | read_unlock(&resource_lock); | |
1123 | ||
1124 | return err; | |
1125 | } | |
1126 | ||
1127 | static int __init strict_iomem(char *str) | |
1128 | { | |
1129 | if (strstr(str, "relaxed")) | |
1130 | strict_iomem_checks = 0; | |
1131 | if (strstr(str, "strict")) | |
1132 | strict_iomem_checks = 1; | |
1133 | return 1; | |
1134 | } | |
1135 | ||
1136 | __setup("iomem=", strict_iomem); |