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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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | |
12 | #include <linux/export.h> |
13 | #include <linux/errno.h> |
14 | #include <linux/ioport.h> |
15 | #include <linux/init.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/spinlock.h> |
18 | #include <linux/fs.h> |
19 | #include <linux/proc_fs.h> |
20 | #include <linux/sched.h> |
21 | #include <linux/seq_file.h> |
22 | #include <linux/device.h> |
23 | #include <linux/pfn.h> |
24 | #include <linux/mm.h> |
25 | #include <asm/io.h> |
26 | |
27 | |
28 | struct resource ioport_resource = { |
29 | .name = "PCI IO", |
30 | .start = 0, |
31 | .end = IO_SPACE_LIMIT, |
32 | .flags = IORESOURCE_IO, |
33 | }; |
34 | EXPORT_SYMBOL(ioport_resource); |
35 | |
36 | struct resource iomem_resource = { |
37 | .name = "PCI mem", |
38 | .start = 0, |
39 | .end = -1, |
40 | .flags = IORESOURCE_MEM, |
41 | }; |
42 | EXPORT_SYMBOL(iomem_resource); |
43 | |
44 | /* constraints to be met while allocating resources */ |
45 | struct resource_constraint { |
46 | resource_size_t min, max, align; |
47 | resource_size_t (*alignf)(void *, const struct resource *, |
48 | resource_size_t, resource_size_t); |
49 | void *alignf_data; |
50 | }; |
51 | |
52 | static DEFINE_RWLOCK(resource_lock); |
53 | |
54 | /* |
55 | * For memory hotplug, there is no way to free resource entries allocated |
56 | * by boot mem after the system is up. So for reusing the resource entry |
57 | * we need to remember the resource. |
58 | */ |
59 | static struct resource *bootmem_resource_free; |
60 | static DEFINE_SPINLOCK(bootmem_resource_lock); |
61 | |
62 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) |
63 | { |
64 | struct resource *p = v; |
65 | (*pos)++; |
66 | if (p->child) |
67 | return p->child; |
68 | while (!p->sibling && p->parent) |
69 | p = p->parent; |
70 | return p->sibling; |
71 | } |
72 | |
73 | #ifdef CONFIG_PROC_FS |
74 | |
75 | enum { MAX_IORES_LEVEL = 5 }; |
76 | |
77 | static void *r_start(struct seq_file *m, loff_t *pos) |
78 | __acquires(resource_lock) |
79 | { |
80 | struct resource *p = m->private; |
81 | loff_t l = 0; |
82 | read_lock(&resource_lock); |
83 | for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) |
84 | ; |
85 | return p; |
86 | } |
87 | |
88 | static void r_stop(struct seq_file *m, void *v) |
89 | __releases(resource_lock) |
90 | { |
91 | read_unlock(&resource_lock); |
92 | } |
93 | |
94 | static int r_show(struct seq_file *m, void *v) |
95 | { |
96 | struct resource *root = m->private; |
97 | struct resource *r = v, *p; |
98 | int width = root->end < 0x10000 ? 4 : 8; |
99 | int depth; |
100 | |
101 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) |
102 | if (p->parent == root) |
103 | break; |
104 | seq_printf(m, "%*s%0*llx-%0*llx : %s\n", |
105 | depth * 2, "", |
106 | width, (unsigned long long) r->start, |
107 | width, (unsigned long long) r->end, |
108 | r->name ? r->name : "<BAD>"); |
109 | return 0; |
110 | } |
111 | |
112 | static const struct seq_operations resource_op = { |
113 | .start = r_start, |
114 | .next = r_next, |
115 | .stop = r_stop, |
116 | .show = r_show, |
117 | }; |
118 | |
119 | static int ioports_open(struct inode *inode, struct file *file) |
120 | { |
121 | int res = seq_open(file, &resource_op); |
122 | if (!res) { |
123 | struct seq_file *m = file->private_data; |
124 | m->private = &ioport_resource; |
125 | } |
126 | return res; |
127 | } |
128 | |
129 | static int iomem_open(struct inode *inode, struct file *file) |
130 | { |
131 | int res = seq_open(file, &resource_op); |
132 | if (!res) { |
133 | struct seq_file *m = file->private_data; |
134 | m->private = &iomem_resource; |
135 | } |
136 | return res; |
137 | } |
138 | |
139 | static const struct file_operations proc_ioports_operations = { |
140 | .open = ioports_open, |
141 | .read = seq_read, |
142 | .llseek = seq_lseek, |
143 | .release = seq_release, |
144 | }; |
145 | |
146 | static const struct file_operations proc_iomem_operations = { |
147 | .open = iomem_open, |
148 | .read = seq_read, |
149 | .llseek = seq_lseek, |
150 | .release = seq_release, |
151 | }; |
152 | |
153 | static int __init ioresources_init(void) |
154 | { |
155 | proc_create("ioports", 0, NULL, &proc_ioports_operations); |
156 | proc_create("iomem", 0, NULL, &proc_iomem_operations); |
157 | return 0; |
158 | } |
159 | __initcall(ioresources_init); |
160 | |
161 | #endif /* CONFIG_PROC_FS */ |
162 | |
163 | static void free_resource(struct resource *res) |
164 | { |
165 | if (!res) |
166 | return; |
167 | |
168 | if (!PageSlab(virt_to_head_page(res))) { |
169 | spin_lock(&bootmem_resource_lock); |
170 | res->sibling = bootmem_resource_free; |
171 | bootmem_resource_free = res; |
172 | spin_unlock(&bootmem_resource_lock); |
173 | } else { |
174 | kfree(res); |
175 | } |
176 | } |
177 | |
178 | static struct resource *alloc_resource(gfp_t flags) |
179 | { |
180 | struct resource *res = NULL; |
181 | |
182 | spin_lock(&bootmem_resource_lock); |
183 | if (bootmem_resource_free) { |
184 | res = bootmem_resource_free; |
185 | bootmem_resource_free = res->sibling; |
186 | } |
187 | spin_unlock(&bootmem_resource_lock); |
188 | |
189 | if (res) |
190 | memset(res, 0, sizeof(struct resource)); |
191 | else |
192 | res = kzalloc(sizeof(struct resource), flags); |
193 | |
194 | return res; |
195 | } |
196 | |
197 | /* Return the conflict entry if you can't request it */ |
198 | static struct resource * __request_resource(struct resource *root, struct resource *new) |
199 | { |
200 | resource_size_t start = new->start; |
201 | resource_size_t end = new->end; |
202 | struct resource *tmp, **p; |
203 | |
204 | if (end < start) |
205 | return root; |
206 | if (start < root->start) |
207 | return root; |
208 | if (end > root->end) |
209 | return root; |
210 | p = &root->child; |
211 | for (;;) { |
212 | tmp = *p; |
213 | if (!tmp || tmp->start > end) { |
214 | new->sibling = tmp; |
215 | *p = new; |
216 | new->parent = root; |
217 | return NULL; |
218 | } |
219 | p = &tmp->sibling; |
220 | if (tmp->end < start) |
221 | continue; |
222 | return tmp; |
223 | } |
224 | } |
225 | |
226 | static int __release_resource(struct resource *old) |
227 | { |
228 | struct resource *tmp, **p; |
229 | |
230 | p = &old->parent->child; |
231 | for (;;) { |
232 | tmp = *p; |
233 | if (!tmp) |
234 | break; |
235 | if (tmp == old) { |
236 | *p = tmp->sibling; |
237 | old->parent = NULL; |
238 | return 0; |
239 | } |
240 | p = &tmp->sibling; |
241 | } |
242 | return -EINVAL; |
243 | } |
244 | |
245 | static void __release_child_resources(struct resource *r) |
246 | { |
247 | struct resource *tmp, *p; |
248 | resource_size_t size; |
249 | |
250 | p = r->child; |
251 | r->child = NULL; |
252 | while (p) { |
253 | tmp = p; |
254 | p = p->sibling; |
255 | |
256 | tmp->parent = NULL; |
257 | tmp->sibling = NULL; |
258 | __release_child_resources(tmp); |
259 | |
260 | printk(KERN_DEBUG "release child resource %pR\n", tmp); |
261 | /* need to restore size, and keep flags */ |
262 | size = resource_size(tmp); |
263 | tmp->start = 0; |
264 | tmp->end = size - 1; |
265 | } |
266 | } |
267 | |
268 | void release_child_resources(struct resource *r) |
269 | { |
270 | write_lock(&resource_lock); |
271 | __release_child_resources(r); |
272 | write_unlock(&resource_lock); |
273 | } |
274 | |
275 | /** |
276 | * request_resource_conflict - request and reserve an I/O or memory resource |
277 | * @root: root resource descriptor |
278 | * @new: resource descriptor desired by caller |
279 | * |
280 | * Returns 0 for success, conflict resource on error. |
281 | */ |
282 | struct resource *request_resource_conflict(struct resource *root, struct resource *new) |
283 | { |
284 | struct resource *conflict; |
285 | |
286 | write_lock(&resource_lock); |
287 | conflict = __request_resource(root, new); |
288 | write_unlock(&resource_lock); |
289 | return conflict; |
290 | } |
291 | |
292 | /** |
293 | * request_resource - request and reserve an I/O or memory resource |
294 | * @root: root resource descriptor |
295 | * @new: resource descriptor desired by caller |
296 | * |
297 | * Returns 0 for success, negative error code on error. |
298 | */ |
299 | int request_resource(struct resource *root, struct resource *new) |
300 | { |
301 | struct resource *conflict; |
302 | |
303 | conflict = request_resource_conflict(root, new); |
304 | return conflict ? -EBUSY : 0; |
305 | } |
306 | |
307 | EXPORT_SYMBOL(request_resource); |
308 | |
309 | /** |
310 | * release_resource - release a previously reserved resource |
311 | * @old: resource pointer |
312 | */ |
313 | int release_resource(struct resource *old) |
314 | { |
315 | int retval; |
316 | |
317 | write_lock(&resource_lock); |
318 | retval = __release_resource(old); |
319 | write_unlock(&resource_lock); |
320 | return retval; |
321 | } |
322 | |
323 | EXPORT_SYMBOL(release_resource); |
324 | |
325 | #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) |
326 | /* |
327 | * Finds the lowest memory reosurce exists within [res->start.res->end) |
328 | * the caller must specify res->start, res->end, res->flags and "name". |
329 | * If found, returns 0, res is overwritten, if not found, returns -1. |
330 | */ |
331 | static int find_next_system_ram(struct resource *res, char *name) |
332 | { |
333 | resource_size_t start, end; |
334 | struct resource *p; |
335 | |
336 | BUG_ON(!res); |
337 | |
338 | start = res->start; |
339 | end = res->end; |
340 | BUG_ON(start >= end); |
341 | |
342 | read_lock(&resource_lock); |
343 | for (p = iomem_resource.child; p ; p = p->sibling) { |
344 | /* system ram is just marked as IORESOURCE_MEM */ |
345 | if (p->flags != res->flags) |
346 | continue; |
347 | if (name && strcmp(p->name, name)) |
348 | continue; |
349 | if (p->start > end) { |
350 | p = NULL; |
351 | break; |
352 | } |
353 | if ((p->end >= start) && (p->start < end)) |
354 | break; |
355 | } |
356 | read_unlock(&resource_lock); |
357 | if (!p) |
358 | return -1; |
359 | /* copy data */ |
360 | if (res->start < p->start) |
361 | res->start = p->start; |
362 | if (res->end > p->end) |
363 | res->end = p->end; |
364 | return 0; |
365 | } |
366 | |
367 | /* |
368 | * This function calls callback against all memory range of "System RAM" |
369 | * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. |
370 | * Now, this function is only for "System RAM". |
371 | */ |
372 | int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, |
373 | void *arg, int (*func)(unsigned long, unsigned long, void *)) |
374 | { |
375 | struct resource res; |
376 | unsigned long pfn, end_pfn; |
377 | u64 orig_end; |
378 | int ret = -1; |
379 | |
380 | res.start = (u64) start_pfn << PAGE_SHIFT; |
381 | res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; |
382 | res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
383 | orig_end = res.end; |
384 | while ((res.start < res.end) && |
385 | (find_next_system_ram(&res, "System RAM") >= 0)) { |
386 | pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; |
387 | end_pfn = (res.end + 1) >> PAGE_SHIFT; |
388 | if (end_pfn > pfn) |
389 | ret = (*func)(pfn, end_pfn - pfn, arg); |
390 | if (ret) |
391 | break; |
392 | res.start = res.end + 1; |
393 | res.end = orig_end; |
394 | } |
395 | return ret; |
396 | } |
397 | |
398 | #endif |
399 | |
400 | static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) |
401 | { |
402 | return 1; |
403 | } |
404 | /* |
405 | * This generic page_is_ram() returns true if specified address is |
406 | * registered as "System RAM" in iomem_resource list. |
407 | */ |
408 | int __weak page_is_ram(unsigned long pfn) |
409 | { |
410 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; |
411 | } |
412 | EXPORT_SYMBOL_GPL(page_is_ram); |
413 | |
414 | void __weak arch_remove_reservations(struct resource *avail) |
415 | { |
416 | } |
417 | |
418 | static resource_size_t simple_align_resource(void *data, |
419 | const struct resource *avail, |
420 | resource_size_t size, |
421 | resource_size_t align) |
422 | { |
423 | return avail->start; |
424 | } |
425 | |
426 | static void resource_clip(struct resource *res, resource_size_t min, |
427 | resource_size_t max) |
428 | { |
429 | if (res->start < min) |
430 | res->start = min; |
431 | if (res->end > max) |
432 | res->end = max; |
433 | } |
434 | |
435 | static bool resource_contains(struct resource *res1, struct resource *res2) |
436 | { |
437 | return res1->start <= res2->start && res1->end >= res2->end; |
438 | } |
439 | |
440 | /* |
441 | * Find empty slot in the resource tree with the given range and |
442 | * alignment constraints |
443 | */ |
444 | static int __find_resource(struct resource *root, struct resource *old, |
445 | struct resource *new, |
446 | resource_size_t size, |
447 | struct resource_constraint *constraint) |
448 | { |
449 | struct resource *this = root->child; |
450 | struct resource tmp = *new, avail, alloc; |
451 | |
452 | tmp.start = root->start; |
453 | /* |
454 | * Skip past an allocated resource that starts at 0, since the assignment |
455 | * of this->start - 1 to tmp->end below would cause an underflow. |
456 | */ |
457 | if (this && this->start == root->start) { |
458 | tmp.start = (this == old) ? old->start : this->end + 1; |
459 | this = this->sibling; |
460 | } |
461 | for(;;) { |
462 | if (this) |
463 | tmp.end = (this == old) ? this->end : this->start - 1; |
464 | else |
465 | tmp.end = root->end; |
466 | |
467 | if (tmp.end < tmp.start) |
468 | goto next; |
469 | |
470 | resource_clip(&tmp, constraint->min, constraint->max); |
471 | arch_remove_reservations(&tmp); |
472 | |
473 | /* Check for overflow after ALIGN() */ |
474 | avail = *new; |
475 | avail.start = ALIGN(tmp.start, constraint->align); |
476 | avail.end = tmp.end; |
477 | if (avail.start >= tmp.start) { |
478 | alloc.start = constraint->alignf(constraint->alignf_data, &avail, |
479 | size, constraint->align); |
480 | alloc.end = alloc.start + size - 1; |
481 | if (resource_contains(&avail, &alloc)) { |
482 | new->start = alloc.start; |
483 | new->end = alloc.end; |
484 | return 0; |
485 | } |
486 | } |
487 | |
488 | next: if (!this || this->end == root->end) |
489 | break; |
490 | |
491 | if (this != old) |
492 | tmp.start = this->end + 1; |
493 | this = this->sibling; |
494 | } |
495 | return -EBUSY; |
496 | } |
497 | |
498 | /* |
499 | * Find empty slot in the resource tree given range and alignment. |
500 | */ |
501 | static int find_resource(struct resource *root, struct resource *new, |
502 | resource_size_t size, |
503 | struct resource_constraint *constraint) |
504 | { |
505 | return __find_resource(root, NULL, new, size, constraint); |
506 | } |
507 | |
508 | /** |
509 | * reallocate_resource - allocate a slot in the resource tree given range & alignment. |
510 | * The resource will be relocated if the new size cannot be reallocated in the |
511 | * current location. |
512 | * |
513 | * @root: root resource descriptor |
514 | * @old: resource descriptor desired by caller |
515 | * @newsize: new size of the resource descriptor |
516 | * @constraint: the size and alignment constraints to be met. |
517 | */ |
518 | int reallocate_resource(struct resource *root, struct resource *old, |
519 | resource_size_t newsize, |
520 | struct resource_constraint *constraint) |
521 | { |
522 | int err=0; |
523 | struct resource new = *old; |
524 | struct resource *conflict; |
525 | |
526 | write_lock(&resource_lock); |
527 | |
528 | if ((err = __find_resource(root, old, &new, newsize, constraint))) |
529 | goto out; |
530 | |
531 | if (resource_contains(&new, old)) { |
532 | old->start = new.start; |
533 | old->end = new.end; |
534 | goto out; |
535 | } |
536 | |
537 | if (old->child) { |
538 | err = -EBUSY; |
539 | goto out; |
540 | } |
541 | |
542 | if (resource_contains(old, &new)) { |
543 | old->start = new.start; |
544 | old->end = new.end; |
545 | } else { |
546 | __release_resource(old); |
547 | *old = new; |
548 | conflict = __request_resource(root, old); |
549 | BUG_ON(conflict); |
550 | } |
551 | out: |
552 | write_unlock(&resource_lock); |
553 | return err; |
554 | } |
555 | |
556 | |
557 | /** |
558 | * allocate_resource - allocate empty slot in the resource tree given range & alignment. |
559 | * The resource will be reallocated with a new size if it was already allocated |
560 | * @root: root resource descriptor |
561 | * @new: resource descriptor desired by caller |
562 | * @size: requested resource region size |
563 | * @min: minimum boundary to allocate |
564 | * @max: maximum boundary to allocate |
565 | * @align: alignment requested, in bytes |
566 | * @alignf: alignment function, optional, called if not NULL |
567 | * @alignf_data: arbitrary data to pass to the @alignf function |
568 | */ |
569 | int allocate_resource(struct resource *root, struct resource *new, |
570 | resource_size_t size, resource_size_t min, |
571 | resource_size_t max, resource_size_t align, |
572 | resource_size_t (*alignf)(void *, |
573 | const struct resource *, |
574 | resource_size_t, |
575 | resource_size_t), |
576 | void *alignf_data) |
577 | { |
578 | int err; |
579 | struct resource_constraint constraint; |
580 | |
581 | if (!alignf) |
582 | alignf = simple_align_resource; |
583 | |
584 | constraint.min = min; |
585 | constraint.max = max; |
586 | constraint.align = align; |
587 | constraint.alignf = alignf; |
588 | constraint.alignf_data = alignf_data; |
589 | |
590 | if ( new->parent ) { |
591 | /* resource is already allocated, try reallocating with |
592 | the new constraints */ |
593 | return reallocate_resource(root, new, size, &constraint); |
594 | } |
595 | |
596 | write_lock(&resource_lock); |
597 | err = find_resource(root, new, size, &constraint); |
598 | if (err >= 0 && __request_resource(root, new)) |
599 | err = -EBUSY; |
600 | write_unlock(&resource_lock); |
601 | return err; |
602 | } |
603 | |
604 | EXPORT_SYMBOL(allocate_resource); |
605 | |
606 | /** |
607 | * lookup_resource - find an existing resource by a resource start address |
608 | * @root: root resource descriptor |
609 | * @start: resource start address |
610 | * |
611 | * Returns a pointer to the resource if found, NULL otherwise |
612 | */ |
613 | struct resource *lookup_resource(struct resource *root, resource_size_t start) |
614 | { |
615 | struct resource *res; |
616 | |
617 | read_lock(&resource_lock); |
618 | for (res = root->child; res; res = res->sibling) { |
619 | if (res->start == start) |
620 | break; |
621 | } |
622 | read_unlock(&resource_lock); |
623 | |
624 | return res; |
625 | } |
626 | |
627 | /* |
628 | * Insert a resource into the resource tree. If successful, return NULL, |
629 | * otherwise return the conflicting resource (compare to __request_resource()) |
630 | */ |
631 | static struct resource * __insert_resource(struct resource *parent, struct resource *new) |
632 | { |
633 | struct resource *first, *next; |
634 | |
635 | for (;; parent = first) { |
636 | first = __request_resource(parent, new); |
637 | if (!first) |
638 | return first; |
639 | |
640 | if (first == parent) |
641 | return first; |
642 | if (WARN_ON(first == new)) /* duplicated insertion */ |
643 | return first; |
644 | |
645 | if ((first->start > new->start) || (first->end < new->end)) |
646 | break; |
647 | if ((first->start == new->start) && (first->end == new->end)) |
648 | break; |
649 | } |
650 | |
651 | for (next = first; ; next = next->sibling) { |
652 | /* Partial overlap? Bad, and unfixable */ |
653 | if (next->start < new->start || next->end > new->end) |
654 | return next; |
655 | if (!next->sibling) |
656 | break; |
657 | if (next->sibling->start > new->end) |
658 | break; |
659 | } |
660 | |
661 | new->parent = parent; |
662 | new->sibling = next->sibling; |
663 | new->child = first; |
664 | |
665 | next->sibling = NULL; |
666 | for (next = first; next; next = next->sibling) |
667 | next->parent = new; |
668 | |
669 | if (parent->child == first) { |
670 | parent->child = new; |
671 | } else { |
672 | next = parent->child; |
673 | while (next->sibling != first) |
674 | next = next->sibling; |
675 | next->sibling = new; |
676 | } |
677 | return NULL; |
678 | } |
679 | |
680 | /** |
681 | * insert_resource_conflict - Inserts resource in the resource tree |
682 | * @parent: parent of the new resource |
683 | * @new: new resource to insert |
684 | * |
685 | * Returns 0 on success, conflict resource if the resource can't be inserted. |
686 | * |
687 | * This function is equivalent to request_resource_conflict when no conflict |
688 | * happens. If a conflict happens, and the conflicting resources |
689 | * entirely fit within the range of the new resource, then the new |
690 | * resource is inserted and the conflicting resources become children of |
691 | * the new resource. |
692 | */ |
693 | struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) |
694 | { |
695 | struct resource *conflict; |
696 | |
697 | write_lock(&resource_lock); |
698 | conflict = __insert_resource(parent, new); |
699 | write_unlock(&resource_lock); |
700 | return conflict; |
701 | } |
702 | |
703 | /** |
704 | * insert_resource - Inserts a resource in the resource tree |
705 | * @parent: parent of the new resource |
706 | * @new: new resource to insert |
707 | * |
708 | * Returns 0 on success, -EBUSY if the resource can't be inserted. |
709 | */ |
710 | int insert_resource(struct resource *parent, struct resource *new) |
711 | { |
712 | struct resource *conflict; |
713 | |
714 | conflict = insert_resource_conflict(parent, new); |
715 | return conflict ? -EBUSY : 0; |
716 | } |
717 | |
718 | /** |
719 | * insert_resource_expand_to_fit - Insert a resource into the resource tree |
720 | * @root: root resource descriptor |
721 | * @new: new resource to insert |
722 | * |
723 | * Insert a resource into the resource tree, possibly expanding it in order |
724 | * to make it encompass any conflicting resources. |
725 | */ |
726 | void insert_resource_expand_to_fit(struct resource *root, struct resource *new) |
727 | { |
728 | if (new->parent) |
729 | return; |
730 | |
731 | write_lock(&resource_lock); |
732 | for (;;) { |
733 | struct resource *conflict; |
734 | |
735 | conflict = __insert_resource(root, new); |
736 | if (!conflict) |
737 | break; |
738 | if (conflict == root) |
739 | break; |
740 | |
741 | /* Ok, expand resource to cover the conflict, then try again .. */ |
742 | if (conflict->start < new->start) |
743 | new->start = conflict->start; |
744 | if (conflict->end > new->end) |
745 | new->end = conflict->end; |
746 | |
747 | printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); |
748 | } |
749 | write_unlock(&resource_lock); |
750 | } |
751 | |
752 | static int __adjust_resource(struct resource *res, resource_size_t start, |
753 | resource_size_t size) |
754 | { |
755 | struct resource *tmp, *parent = res->parent; |
756 | resource_size_t end = start + size - 1; |
757 | int result = -EBUSY; |
758 | |
759 | if (!parent) |
760 | goto skip; |
761 | |
762 | if ((start < parent->start) || (end > parent->end)) |
763 | goto out; |
764 | |
765 | if (res->sibling && (res->sibling->start <= end)) |
766 | goto out; |
767 | |
768 | tmp = parent->child; |
769 | if (tmp != res) { |
770 | while (tmp->sibling != res) |
771 | tmp = tmp->sibling; |
772 | if (start <= tmp->end) |
773 | goto out; |
774 | } |
775 | |
776 | skip: |
777 | for (tmp = res->child; tmp; tmp = tmp->sibling) |
778 | if ((tmp->start < start) || (tmp->end > end)) |
779 | goto out; |
780 | |
781 | res->start = start; |
782 | res->end = end; |
783 | result = 0; |
784 | |
785 | out: |
786 | return result; |
787 | } |
788 | |
789 | /** |
790 | * adjust_resource - modify a resource's start and size |
791 | * @res: resource to modify |
792 | * @start: new start value |
793 | * @size: new size |
794 | * |
795 | * Given an existing resource, change its start and size to match the |
796 | * arguments. Returns 0 on success, -EBUSY if it can't fit. |
797 | * Existing children of the resource are assumed to be immutable. |
798 | */ |
799 | int adjust_resource(struct resource *res, resource_size_t start, |
800 | resource_size_t size) |
801 | { |
802 | int result; |
803 | |
804 | write_lock(&resource_lock); |
805 | result = __adjust_resource(res, start, size); |
806 | write_unlock(&resource_lock); |
807 | return result; |
808 | } |
809 | EXPORT_SYMBOL(adjust_resource); |
810 | |
811 | static void __init __reserve_region_with_split(struct resource *root, |
812 | resource_size_t start, resource_size_t end, |
813 | const char *name) |
814 | { |
815 | struct resource *parent = root; |
816 | struct resource *conflict; |
817 | struct resource *res = alloc_resource(GFP_ATOMIC); |
818 | struct resource *next_res = NULL; |
819 | |
820 | if (!res) |
821 | return; |
822 | |
823 | res->name = name; |
824 | res->start = start; |
825 | res->end = end; |
826 | res->flags = IORESOURCE_BUSY; |
827 | |
828 | while (1) { |
829 | |
830 | conflict = __request_resource(parent, res); |
831 | if (!conflict) { |
832 | if (!next_res) |
833 | break; |
834 | res = next_res; |
835 | next_res = NULL; |
836 | continue; |
837 | } |
838 | |
839 | /* conflict covered whole area */ |
840 | if (conflict->start <= res->start && |
841 | conflict->end >= res->end) { |
842 | free_resource(res); |
843 | WARN_ON(next_res); |
844 | break; |
845 | } |
846 | |
847 | /* failed, split and try again */ |
848 | if (conflict->start > res->start) { |
849 | end = res->end; |
850 | res->end = conflict->start - 1; |
851 | if (conflict->end < end) { |
852 | next_res = alloc_resource(GFP_ATOMIC); |
853 | if (!next_res) { |
854 | free_resource(res); |
855 | break; |
856 | } |
857 | next_res->name = name; |
858 | next_res->start = conflict->end + 1; |
859 | next_res->end = end; |
860 | next_res->flags = IORESOURCE_BUSY; |
861 | } |
862 | } else { |
863 | res->start = conflict->end + 1; |
864 | } |
865 | } |
866 | |
867 | } |
868 | |
869 | void __init reserve_region_with_split(struct resource *root, |
870 | resource_size_t start, resource_size_t end, |
871 | const char *name) |
872 | { |
873 | int abort = 0; |
874 | |
875 | write_lock(&resource_lock); |
876 | if (root->start > start || root->end < end) { |
877 | pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", |
878 | (unsigned long long)start, (unsigned long long)end, |
879 | root); |
880 | if (start > root->end || end < root->start) |
881 | abort = 1; |
882 | else { |
883 | if (end > root->end) |
884 | end = root->end; |
885 | if (start < root->start) |
886 | start = root->start; |
887 | pr_err("fixing request to [0x%llx-0x%llx]\n", |
888 | (unsigned long long)start, |
889 | (unsigned long long)end); |
890 | } |
891 | dump_stack(); |
892 | } |
893 | if (!abort) |
894 | __reserve_region_with_split(root, start, end, name); |
895 | write_unlock(&resource_lock); |
896 | } |
897 | |
898 | /** |
899 | * resource_alignment - calculate resource's alignment |
900 | * @res: resource pointer |
901 | * |
902 | * Returns alignment on success, 0 (invalid alignment) on failure. |
903 | */ |
904 | resource_size_t resource_alignment(struct resource *res) |
905 | { |
906 | switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { |
907 | case IORESOURCE_SIZEALIGN: |
908 | return resource_size(res); |
909 | case IORESOURCE_STARTALIGN: |
910 | return res->start; |
911 | default: |
912 | return 0; |
913 | } |
914 | } |
915 | |
916 | /* |
917 | * This is compatibility stuff for IO resources. |
918 | * |
919 | * Note how this, unlike the above, knows about |
920 | * the IO flag meanings (busy etc). |
921 | * |
922 | * request_region creates a new busy region. |
923 | * |
924 | * check_region returns non-zero if the area is already busy. |
925 | * |
926 | * release_region releases a matching busy region. |
927 | */ |
928 | |
929 | static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); |
930 | |
931 | /** |
932 | * __request_region - create a new busy resource region |
933 | * @parent: parent resource descriptor |
934 | * @start: resource start address |
935 | * @n: resource region size |
936 | * @name: reserving caller's ID string |
937 | * @flags: IO resource flags |
938 | */ |
939 | struct resource * __request_region(struct resource *parent, |
940 | resource_size_t start, resource_size_t n, |
941 | const char *name, int flags) |
942 | { |
943 | DECLARE_WAITQUEUE(wait, current); |
944 | struct resource *res = alloc_resource(GFP_KERNEL); |
945 | |
946 | if (!res) |
947 | return NULL; |
948 | |
949 | res->name = name; |
950 | res->start = start; |
951 | res->end = start + n - 1; |
952 | res->flags = IORESOURCE_BUSY; |
953 | res->flags |= flags; |
954 | |
955 | write_lock(&resource_lock); |
956 | |
957 | for (;;) { |
958 | struct resource *conflict; |
959 | |
960 | conflict = __request_resource(parent, res); |
961 | if (!conflict) |
962 | break; |
963 | if (conflict != parent) { |
964 | parent = conflict; |
965 | if (!(conflict->flags & IORESOURCE_BUSY)) |
966 | continue; |
967 | } |
968 | if (conflict->flags & flags & IORESOURCE_MUXED) { |
969 | add_wait_queue(&muxed_resource_wait, &wait); |
970 | write_unlock(&resource_lock); |
971 | set_current_state(TASK_UNINTERRUPTIBLE); |
972 | schedule(); |
973 | remove_wait_queue(&muxed_resource_wait, &wait); |
974 | write_lock(&resource_lock); |
975 | continue; |
976 | } |
977 | /* Uhhuh, that didn't work out.. */ |
978 | free_resource(res); |
979 | res = NULL; |
980 | break; |
981 | } |
982 | write_unlock(&resource_lock); |
983 | return res; |
984 | } |
985 | EXPORT_SYMBOL(__request_region); |
986 | |
987 | /** |
988 | * __check_region - check if a resource region is busy or free |
989 | * @parent: parent resource descriptor |
990 | * @start: resource start address |
991 | * @n: resource region size |
992 | * |
993 | * Returns 0 if the region is free at the moment it is checked, |
994 | * returns %-EBUSY if the region is busy. |
995 | * |
996 | * NOTE: |
997 | * This function is deprecated because its use is racy. |
998 | * Even if it returns 0, a subsequent call to request_region() |
999 | * may fail because another driver etc. just allocated the region. |
1000 | * Do NOT use it. It will be removed from the kernel. |
1001 | */ |
1002 | int __check_region(struct resource *parent, resource_size_t start, |
1003 | resource_size_t n) |
1004 | { |
1005 | struct resource * res; |
1006 | |
1007 | res = __request_region(parent, start, n, "check-region", 0); |
1008 | if (!res) |
1009 | return -EBUSY; |
1010 | |
1011 | release_resource(res); |
1012 | free_resource(res); |
1013 | return 0; |
1014 | } |
1015 | EXPORT_SYMBOL(__check_region); |
1016 | |
1017 | /** |
1018 | * __release_region - release a previously reserved resource region |
1019 | * @parent: parent resource descriptor |
1020 | * @start: resource start address |
1021 | * @n: resource region size |
1022 | * |
1023 | * The described resource region must match a currently busy region. |
1024 | */ |
1025 | void __release_region(struct resource *parent, resource_size_t start, |
1026 | resource_size_t n) |
1027 | { |
1028 | struct resource **p; |
1029 | resource_size_t end; |
1030 | |
1031 | p = &parent->child; |
1032 | end = start + n - 1; |
1033 | |
1034 | write_lock(&resource_lock); |
1035 | |
1036 | for (;;) { |
1037 | struct resource *res = *p; |
1038 | |
1039 | if (!res) |
1040 | break; |
1041 | if (res->start <= start && res->end >= end) { |
1042 | if (!(res->flags & IORESOURCE_BUSY)) { |
1043 | p = &res->child; |
1044 | continue; |
1045 | } |
1046 | if (res->start != start || res->end != end) |
1047 | break; |
1048 | *p = res->sibling; |
1049 | write_unlock(&resource_lock); |
1050 | if (res->flags & IORESOURCE_MUXED) |
1051 | wake_up(&muxed_resource_wait); |
1052 | free_resource(res); |
1053 | return; |
1054 | } |
1055 | p = &res->sibling; |
1056 | } |
1057 | |
1058 | write_unlock(&resource_lock); |
1059 | |
1060 | printk(KERN_WARNING "Trying to free nonexistent resource " |
1061 | "<%016llx-%016llx>\n", (unsigned long long)start, |
1062 | (unsigned long long)end); |
1063 | } |
1064 | EXPORT_SYMBOL(__release_region); |
1065 | |
1066 | #ifdef CONFIG_MEMORY_HOTREMOVE |
1067 | /** |
1068 | * release_mem_region_adjustable - release a previously reserved memory region |
1069 | * @parent: parent resource descriptor |
1070 | * @start: resource start address |
1071 | * @size: resource region size |
1072 | * |
1073 | * This interface is intended for memory hot-delete. The requested region |
1074 | * is released from a currently busy memory resource. The requested region |
1075 | * must either match exactly or fit into a single busy resource entry. In |
1076 | * the latter case, the remaining resource is adjusted accordingly. |
1077 | * Existing children of the busy memory resource must be immutable in the |
1078 | * request. |
1079 | * |
1080 | * Note: |
1081 | * - Additional release conditions, such as overlapping region, can be |
1082 | * supported after they are confirmed as valid cases. |
1083 | * - When a busy memory resource gets split into two entries, the code |
1084 | * assumes that all children remain in the lower address entry for |
1085 | * simplicity. Enhance this logic when necessary. |
1086 | */ |
1087 | int release_mem_region_adjustable(struct resource *parent, |
1088 | resource_size_t start, resource_size_t size) |
1089 | { |
1090 | struct resource **p; |
1091 | struct resource *res; |
1092 | struct resource *new_res; |
1093 | resource_size_t end; |
1094 | int ret = -EINVAL; |
1095 | |
1096 | end = start + size - 1; |
1097 | if ((start < parent->start) || (end > parent->end)) |
1098 | return ret; |
1099 | |
1100 | /* The alloc_resource() result gets checked later */ |
1101 | new_res = alloc_resource(GFP_KERNEL); |
1102 | |
1103 | p = &parent->child; |
1104 | write_lock(&resource_lock); |
1105 | |
1106 | while ((res = *p)) { |
1107 | if (res->start >= end) |
1108 | break; |
1109 | |
1110 | /* look for the next resource if it does not fit into */ |
1111 | if (res->start > start || res->end < end) { |
1112 | p = &res->sibling; |
1113 | continue; |
1114 | } |
1115 | |
1116 | if (!(res->flags & IORESOURCE_MEM)) |
1117 | break; |
1118 | |
1119 | if (!(res->flags & IORESOURCE_BUSY)) { |
1120 | p = &res->child; |
1121 | continue; |
1122 | } |
1123 | |
1124 | /* found the target resource; let's adjust accordingly */ |
1125 | if (res->start == start && res->end == end) { |
1126 | /* free the whole entry */ |
1127 | *p = res->sibling; |
1128 | free_resource(res); |
1129 | ret = 0; |
1130 | } else if (res->start == start && res->end != end) { |
1131 | /* adjust the start */ |
1132 | ret = __adjust_resource(res, end + 1, |
1133 | res->end - end); |
1134 | } else if (res->start != start && res->end == end) { |
1135 | /* adjust the end */ |
1136 | ret = __adjust_resource(res, res->start, |
1137 | start - res->start); |
1138 | } else { |
1139 | /* split into two entries */ |
1140 | if (!new_res) { |
1141 | ret = -ENOMEM; |
1142 | break; |
1143 | } |
1144 | new_res->name = res->name; |
1145 | new_res->start = end + 1; |
1146 | new_res->end = res->end; |
1147 | new_res->flags = res->flags; |
1148 | new_res->parent = res->parent; |
1149 | new_res->sibling = res->sibling; |
1150 | new_res->child = NULL; |
1151 | |
1152 | ret = __adjust_resource(res, res->start, |
1153 | start - res->start); |
1154 | if (ret) |
1155 | break; |
1156 | res->sibling = new_res; |
1157 | new_res = NULL; |
1158 | } |
1159 | |
1160 | break; |
1161 | } |
1162 | |
1163 | write_unlock(&resource_lock); |
1164 | free_resource(new_res); |
1165 | return ret; |
1166 | } |
1167 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |
1168 | |
1169 | /* |
1170 | * Managed region resource |
1171 | */ |
1172 | struct region_devres { |
1173 | struct resource *parent; |
1174 | resource_size_t start; |
1175 | resource_size_t n; |
1176 | }; |
1177 | |
1178 | static void devm_region_release(struct device *dev, void *res) |
1179 | { |
1180 | struct region_devres *this = res; |
1181 | |
1182 | __release_region(this->parent, this->start, this->n); |
1183 | } |
1184 | |
1185 | static int devm_region_match(struct device *dev, void *res, void *match_data) |
1186 | { |
1187 | struct region_devres *this = res, *match = match_data; |
1188 | |
1189 | return this->parent == match->parent && |
1190 | this->start == match->start && this->n == match->n; |
1191 | } |
1192 | |
1193 | struct resource * __devm_request_region(struct device *dev, |
1194 | struct resource *parent, resource_size_t start, |
1195 | resource_size_t n, const char *name) |
1196 | { |
1197 | struct region_devres *dr = NULL; |
1198 | struct resource *res; |
1199 | |
1200 | dr = devres_alloc(devm_region_release, sizeof(struct region_devres), |
1201 | GFP_KERNEL); |
1202 | if (!dr) |
1203 | return NULL; |
1204 | |
1205 | dr->parent = parent; |
1206 | dr->start = start; |
1207 | dr->n = n; |
1208 | |
1209 | res = __request_region(parent, start, n, name, 0); |
1210 | if (res) |
1211 | devres_add(dev, dr); |
1212 | else |
1213 | devres_free(dr); |
1214 | |
1215 | return res; |
1216 | } |
1217 | EXPORT_SYMBOL(__devm_request_region); |
1218 | |
1219 | void __devm_release_region(struct device *dev, struct resource *parent, |
1220 | resource_size_t start, resource_size_t n) |
1221 | { |
1222 | struct region_devres match_data = { parent, start, n }; |
1223 | |
1224 | __release_region(parent, start, n); |
1225 | WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, |
1226 | &match_data)); |
1227 | } |
1228 | EXPORT_SYMBOL(__devm_release_region); |
1229 | |
1230 | /* |
1231 | * Called from init/main.c to reserve IO ports. |
1232 | */ |
1233 | #define MAXRESERVE 4 |
1234 | static int __init reserve_setup(char *str) |
1235 | { |
1236 | static int reserved; |
1237 | static struct resource reserve[MAXRESERVE]; |
1238 | |
1239 | for (;;) { |
1240 | unsigned int io_start, io_num; |
1241 | int x = reserved; |
1242 | |
1243 | if (get_option (&str, &io_start) != 2) |
1244 | break; |
1245 | if (get_option (&str, &io_num) == 0) |
1246 | break; |
1247 | if (x < MAXRESERVE) { |
1248 | struct resource *res = reserve + x; |
1249 | res->name = "reserved"; |
1250 | res->start = io_start; |
1251 | res->end = io_start + io_num - 1; |
1252 | res->flags = IORESOURCE_BUSY; |
1253 | res->child = NULL; |
1254 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) |
1255 | reserved = x+1; |
1256 | } |
1257 | } |
1258 | return 1; |
1259 | } |
1260 | |
1261 | __setup("reserve=", reserve_setup); |
1262 | |
1263 | /* |
1264 | * Check if the requested addr and size spans more than any slot in the |
1265 | * iomem resource tree. |
1266 | */ |
1267 | int iomem_map_sanity_check(resource_size_t addr, unsigned long size) |
1268 | { |
1269 | struct resource *p = &iomem_resource; |
1270 | int err = 0; |
1271 | loff_t l; |
1272 | |
1273 | read_lock(&resource_lock); |
1274 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { |
1275 | /* |
1276 | * We can probably skip the resources without |
1277 | * IORESOURCE_IO attribute? |
1278 | */ |
1279 | if (p->start >= addr + size) |
1280 | continue; |
1281 | if (p->end < addr) |
1282 | continue; |
1283 | if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && |
1284 | PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) |
1285 | continue; |
1286 | /* |
1287 | * if a resource is "BUSY", it's not a hardware resource |
1288 | * but a driver mapping of such a resource; we don't want |
1289 | * to warn for those; some drivers legitimately map only |
1290 | * partial hardware resources. (example: vesafb) |
1291 | */ |
1292 | if (p->flags & IORESOURCE_BUSY) |
1293 | continue; |
1294 | |
1295 | printk(KERN_WARNING "resource map sanity check conflict: " |
1296 | "0x%llx 0x%llx 0x%llx 0x%llx %s\n", |
1297 | (unsigned long long)addr, |
1298 | (unsigned long long)(addr + size - 1), |
1299 | (unsigned long long)p->start, |
1300 | (unsigned long long)p->end, |
1301 | p->name); |
1302 | err = -1; |
1303 | break; |
1304 | } |
1305 | read_unlock(&resource_lock); |
1306 | |
1307 | return err; |
1308 | } |
1309 | |
1310 | #ifdef CONFIG_STRICT_DEVMEM |
1311 | static int strict_iomem_checks = 1; |
1312 | #else |
1313 | static int strict_iomem_checks; |
1314 | #endif |
1315 | |
1316 | /* |
1317 | * check if an address is reserved in the iomem resource tree |
1318 | * returns 1 if reserved, 0 if not reserved. |
1319 | */ |
1320 | int iomem_is_exclusive(u64 addr) |
1321 | { |
1322 | struct resource *p = &iomem_resource; |
1323 | int err = 0; |
1324 | loff_t l; |
1325 | int size = PAGE_SIZE; |
1326 | |
1327 | if (!strict_iomem_checks) |
1328 | return 0; |
1329 | |
1330 | addr = addr & PAGE_MASK; |
1331 | |
1332 | read_lock(&resource_lock); |
1333 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { |
1334 | /* |
1335 | * We can probably skip the resources without |
1336 | * IORESOURCE_IO attribute? |
1337 | */ |
1338 | if (p->start >= addr + size) |
1339 | break; |
1340 | if (p->end < addr) |
1341 | continue; |
1342 | if (p->flags & IORESOURCE_BUSY && |
1343 | p->flags & IORESOURCE_EXCLUSIVE) { |
1344 | err = 1; |
1345 | break; |
1346 | } |
1347 | } |
1348 | read_unlock(&resource_lock); |
1349 | |
1350 | return err; |
1351 | } |
1352 | |
1353 | static int __init strict_iomem(char *str) |
1354 | { |
1355 | if (strstr(str, "relaxed")) |
1356 | strict_iomem_checks = 0; |
1357 | if (strstr(str, "strict")) |
1358 | strict_iomem_checks = 1; |
1359 | return 1; |
1360 | } |
1361 | |
1362 | __setup("iomem=", strict_iomem); |
1363 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9