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Source at commit b05a5adf03613de371c77c3235f7d970d7cd0c71 created 13 years 1 month ago. By Lars-Peter Clausen, NAND: Optimize reading the eec data for the JZ4740 (evil hack) | |
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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 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) |
44 | { |
45 | struct resource *p = v; |
46 | (*pos)++; |
47 | if (p->child) |
48 | return p->child; |
49 | while (!p->sibling && p->parent) |
50 | p = p->parent; |
51 | return p->sibling; |
52 | } |
53 | |
54 | #ifdef CONFIG_PROC_FS |
55 | |
56 | enum { MAX_IORES_LEVEL = 5 }; |
57 | |
58 | static void *r_start(struct seq_file *m, loff_t *pos) |
59 | __acquires(resource_lock) |
60 | { |
61 | struct resource *p = m->private; |
62 | loff_t l = 0; |
63 | read_lock(&resource_lock); |
64 | for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) |
65 | ; |
66 | return p; |
67 | } |
68 | |
69 | static void r_stop(struct seq_file *m, void *v) |
70 | __releases(resource_lock) |
71 | { |
72 | read_unlock(&resource_lock); |
73 | } |
74 | |
75 | static int r_show(struct seq_file *m, void *v) |
76 | { |
77 | struct resource *root = m->private; |
78 | struct resource *r = v, *p; |
79 | int width = root->end < 0x10000 ? 4 : 8; |
80 | int depth; |
81 | |
82 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) |
83 | if (p->parent == root) |
84 | break; |
85 | seq_printf(m, "%*s%0*llx-%0*llx : %s\n", |
86 | depth * 2, "", |
87 | width, (unsigned long long) r->start, |
88 | width, (unsigned long long) r->end, |
89 | r->name ? r->name : "<BAD>"); |
90 | return 0; |
91 | } |
92 | |
93 | static const struct seq_operations resource_op = { |
94 | .start = r_start, |
95 | .next = r_next, |
96 | .stop = r_stop, |
97 | .show = r_show, |
98 | }; |
99 | |
100 | static int ioports_open(struct inode *inode, struct file *file) |
101 | { |
102 | int res = seq_open(file, &resource_op); |
103 | if (!res) { |
104 | struct seq_file *m = file->private_data; |
105 | m->private = &ioport_resource; |
106 | } |
107 | return res; |
108 | } |
109 | |
110 | static int iomem_open(struct inode *inode, struct file *file) |
111 | { |
112 | int res = seq_open(file, &resource_op); |
113 | if (!res) { |
114 | struct seq_file *m = file->private_data; |
115 | m->private = &iomem_resource; |
116 | } |
117 | return res; |
118 | } |
119 | |
120 | static const struct file_operations proc_ioports_operations = { |
121 | .open = ioports_open, |
122 | .read = seq_read, |
123 | .llseek = seq_lseek, |
124 | .release = seq_release, |
125 | }; |
126 | |
127 | static const struct file_operations proc_iomem_operations = { |
128 | .open = iomem_open, |
129 | .read = seq_read, |
130 | .llseek = seq_lseek, |
131 | .release = seq_release, |
132 | }; |
133 | |
134 | static int __init ioresources_init(void) |
135 | { |
136 | proc_create("ioports", 0, NULL, &proc_ioports_operations); |
137 | proc_create("iomem", 0, NULL, &proc_iomem_operations); |
138 | return 0; |
139 | } |
140 | __initcall(ioresources_init); |
141 | |
142 | #endif /* CONFIG_PROC_FS */ |
143 | |
144 | /* Return the conflict entry if you can't request it */ |
145 | static struct resource * __request_resource(struct resource *root, struct resource *new) |
146 | { |
147 | resource_size_t start = new->start; |
148 | resource_size_t end = new->end; |
149 | struct resource *tmp, **p; |
150 | |
151 | if (end < start) |
152 | return root; |
153 | if (start < root->start) |
154 | return root; |
155 | if (end > root->end) |
156 | return root; |
157 | p = &root->child; |
158 | for (;;) { |
159 | tmp = *p; |
160 | if (!tmp || tmp->start > end) { |
161 | new->sibling = tmp; |
162 | *p = new; |
163 | new->parent = root; |
164 | return NULL; |
165 | } |
166 | p = &tmp->sibling; |
167 | if (tmp->end < start) |
168 | continue; |
169 | return tmp; |
170 | } |
171 | } |
172 | |
173 | static int __release_resource(struct resource *old) |
174 | { |
175 | struct resource *tmp, **p; |
176 | |
177 | p = &old->parent->child; |
178 | for (;;) { |
179 | tmp = *p; |
180 | if (!tmp) |
181 | break; |
182 | if (tmp == old) { |
183 | *p = tmp->sibling; |
184 | old->parent = NULL; |
185 | return 0; |
186 | } |
187 | p = &tmp->sibling; |
188 | } |
189 | return -EINVAL; |
190 | } |
191 | |
192 | static void __release_child_resources(struct resource *r) |
193 | { |
194 | struct resource *tmp, *p; |
195 | resource_size_t size; |
196 | |
197 | p = r->child; |
198 | r->child = NULL; |
199 | while (p) { |
200 | tmp = p; |
201 | p = p->sibling; |
202 | |
203 | tmp->parent = NULL; |
204 | tmp->sibling = NULL; |
205 | __release_child_resources(tmp); |
206 | |
207 | printk(KERN_DEBUG "release child resource %pR\n", tmp); |
208 | /* need to restore size, and keep flags */ |
209 | size = resource_size(tmp); |
210 | tmp->start = 0; |
211 | tmp->end = size - 1; |
212 | } |
213 | } |
214 | |
215 | void release_child_resources(struct resource *r) |
216 | { |
217 | write_lock(&resource_lock); |
218 | __release_child_resources(r); |
219 | write_unlock(&resource_lock); |
220 | } |
221 | |
222 | /** |
223 | * request_resource_conflict - request and reserve an I/O or memory resource |
224 | * @root: root resource descriptor |
225 | * @new: resource descriptor desired by caller |
226 | * |
227 | * Returns 0 for success, conflict resource on error. |
228 | */ |
229 | struct resource *request_resource_conflict(struct resource *root, struct resource *new) |
230 | { |
231 | struct resource *conflict; |
232 | |
233 | write_lock(&resource_lock); |
234 | conflict = __request_resource(root, new); |
235 | write_unlock(&resource_lock); |
236 | return conflict; |
237 | } |
238 | |
239 | /** |
240 | * request_resource - 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, negative error code on error. |
245 | */ |
246 | int request_resource(struct resource *root, struct resource *new) |
247 | { |
248 | struct resource *conflict; |
249 | |
250 | conflict = request_resource_conflict(root, new); |
251 | return conflict ? -EBUSY : 0; |
252 | } |
253 | |
254 | EXPORT_SYMBOL(request_resource); |
255 | |
256 | /** |
257 | * release_resource - release a previously reserved resource |
258 | * @old: resource pointer |
259 | */ |
260 | int release_resource(struct resource *old) |
261 | { |
262 | int retval; |
263 | |
264 | write_lock(&resource_lock); |
265 | retval = __release_resource(old); |
266 | write_unlock(&resource_lock); |
267 | return retval; |
268 | } |
269 | |
270 | EXPORT_SYMBOL(release_resource); |
271 | |
272 | #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) |
273 | /* |
274 | * Finds the lowest memory reosurce exists within [res->start.res->end) |
275 | * the caller must specify res->start, res->end, res->flags and "name". |
276 | * If found, returns 0, res is overwritten, if not found, returns -1. |
277 | */ |
278 | static int find_next_system_ram(struct resource *res, char *name) |
279 | { |
280 | resource_size_t start, end; |
281 | struct resource *p; |
282 | |
283 | BUG_ON(!res); |
284 | |
285 | start = res->start; |
286 | end = res->end; |
287 | BUG_ON(start >= end); |
288 | |
289 | read_lock(&resource_lock); |
290 | for (p = iomem_resource.child; p ; p = p->sibling) { |
291 | /* system ram is just marked as IORESOURCE_MEM */ |
292 | if (p->flags != res->flags) |
293 | continue; |
294 | if (name && strcmp(p->name, name)) |
295 | continue; |
296 | if (p->start > end) { |
297 | p = NULL; |
298 | break; |
299 | } |
300 | if ((p->end >= start) && (p->start < end)) |
301 | break; |
302 | } |
303 | read_unlock(&resource_lock); |
304 | if (!p) |
305 | return -1; |
306 | /* copy data */ |
307 | if (res->start < p->start) |
308 | res->start = p->start; |
309 | if (res->end > p->end) |
310 | res->end = p->end; |
311 | return 0; |
312 | } |
313 | |
314 | /* |
315 | * This function calls callback against all memory range of "System RAM" |
316 | * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. |
317 | * Now, this function is only for "System RAM". |
318 | */ |
319 | int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, |
320 | void *arg, int (*func)(unsigned long, unsigned long, void *)) |
321 | { |
322 | struct resource res; |
323 | unsigned long pfn, end_pfn; |
324 | u64 orig_end; |
325 | int ret = -1; |
326 | |
327 | res.start = (u64) start_pfn << PAGE_SHIFT; |
328 | res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; |
329 | res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
330 | orig_end = res.end; |
331 | while ((res.start < res.end) && |
332 | (find_next_system_ram(&res, "System RAM") >= 0)) { |
333 | pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; |
334 | end_pfn = (res.end + 1) >> PAGE_SHIFT; |
335 | if (end_pfn > pfn) |
336 | ret = (*func)(pfn, end_pfn - pfn, arg); |
337 | if (ret) |
338 | break; |
339 | res.start = res.end + 1; |
340 | res.end = orig_end; |
341 | } |
342 | return ret; |
343 | } |
344 | |
345 | #endif |
346 | |
347 | static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) |
348 | { |
349 | return 1; |
350 | } |
351 | /* |
352 | * This generic page_is_ram() returns true if specified address is |
353 | * registered as "System RAM" in iomem_resource list. |
354 | */ |
355 | int __weak page_is_ram(unsigned long pfn) |
356 | { |
357 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; |
358 | } |
359 | |
360 | void __weak arch_remove_reservations(struct resource *avail) |
361 | { |
362 | } |
363 | |
364 | static resource_size_t simple_align_resource(void *data, |
365 | const struct resource *avail, |
366 | resource_size_t size, |
367 | resource_size_t align) |
368 | { |
369 | return avail->start; |
370 | } |
371 | |
372 | static void resource_clip(struct resource *res, resource_size_t min, |
373 | resource_size_t max) |
374 | { |
375 | if (res->start < min) |
376 | res->start = min; |
377 | if (res->end > max) |
378 | res->end = max; |
379 | } |
380 | |
381 | static bool resource_contains(struct resource *res1, struct resource *res2) |
382 | { |
383 | return res1->start <= res2->start && res1->end >= res2->end; |
384 | } |
385 | |
386 | /* |
387 | * Find empty slot in the resource tree given range and alignment. |
388 | */ |
389 | static int find_resource(struct resource *root, struct resource *new, |
390 | resource_size_t size, resource_size_t min, |
391 | resource_size_t max, resource_size_t align, |
392 | resource_size_t (*alignf)(void *, |
393 | const struct resource *, |
394 | resource_size_t, |
395 | resource_size_t), |
396 | void *alignf_data) |
397 | { |
398 | struct resource *this = root->child; |
399 | struct resource tmp = *new, avail, alloc; |
400 | |
401 | tmp.flags = new->flags; |
402 | tmp.start = root->start; |
403 | /* |
404 | * Skip past an allocated resource that starts at 0, since the assignment |
405 | * of this->start - 1 to tmp->end below would cause an underflow. |
406 | */ |
407 | if (this && this->start == 0) { |
408 | tmp.start = this->end + 1; |
409 | this = this->sibling; |
410 | } |
411 | for(;;) { |
412 | if (this) |
413 | tmp.end = this->start - 1; |
414 | else |
415 | tmp.end = root->end; |
416 | |
417 | resource_clip(&tmp, min, max); |
418 | arch_remove_reservations(&tmp); |
419 | |
420 | /* Check for overflow after ALIGN() */ |
421 | avail = *new; |
422 | avail.start = ALIGN(tmp.start, align); |
423 | avail.end = tmp.end; |
424 | if (avail.start >= tmp.start) { |
425 | alloc.start = alignf(alignf_data, &avail, size, align); |
426 | alloc.end = alloc.start + size - 1; |
427 | if (resource_contains(&avail, &alloc)) { |
428 | new->start = alloc.start; |
429 | new->end = alloc.end; |
430 | return 0; |
431 | } |
432 | } |
433 | if (!this) |
434 | break; |
435 | tmp.start = this->end + 1; |
436 | this = this->sibling; |
437 | } |
438 | return -EBUSY; |
439 | } |
440 | |
441 | /** |
442 | * allocate_resource - allocate empty slot in the resource tree given range & alignment |
443 | * @root: root resource descriptor |
444 | * @new: resource descriptor desired by caller |
445 | * @size: requested resource region size |
446 | * @min: minimum size to allocate |
447 | * @max: maximum size to allocate |
448 | * @align: alignment requested, in bytes |
449 | * @alignf: alignment function, optional, called if not NULL |
450 | * @alignf_data: arbitrary data to pass to the @alignf function |
451 | */ |
452 | int allocate_resource(struct resource *root, struct resource *new, |
453 | resource_size_t size, resource_size_t min, |
454 | resource_size_t max, resource_size_t align, |
455 | resource_size_t (*alignf)(void *, |
456 | const struct resource *, |
457 | resource_size_t, |
458 | resource_size_t), |
459 | void *alignf_data) |
460 | { |
461 | int err; |
462 | |
463 | if (!alignf) |
464 | alignf = simple_align_resource; |
465 | |
466 | write_lock(&resource_lock); |
467 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); |
468 | if (err >= 0 && __request_resource(root, new)) |
469 | err = -EBUSY; |
470 | write_unlock(&resource_lock); |
471 | return err; |
472 | } |
473 | |
474 | EXPORT_SYMBOL(allocate_resource); |
475 | |
476 | /* |
477 | * Insert a resource into the resource tree. If successful, return NULL, |
478 | * otherwise return the conflicting resource (compare to __request_resource()) |
479 | */ |
480 | static struct resource * __insert_resource(struct resource *parent, struct resource *new) |
481 | { |
482 | struct resource *first, *next; |
483 | |
484 | for (;; parent = first) { |
485 | first = __request_resource(parent, new); |
486 | if (!first) |
487 | return first; |
488 | |
489 | if (first == parent) |
490 | return first; |
491 | if (WARN_ON(first == new)) /* duplicated insertion */ |
492 | return first; |
493 | |
494 | if ((first->start > new->start) || (first->end < new->end)) |
495 | break; |
496 | if ((first->start == new->start) && (first->end == new->end)) |
497 | break; |
498 | } |
499 | |
500 | for (next = first; ; next = next->sibling) { |
501 | /* Partial overlap? Bad, and unfixable */ |
502 | if (next->start < new->start || next->end > new->end) |
503 | return next; |
504 | if (!next->sibling) |
505 | break; |
506 | if (next->sibling->start > new->end) |
507 | break; |
508 | } |
509 | |
510 | new->parent = parent; |
511 | new->sibling = next->sibling; |
512 | new->child = first; |
513 | |
514 | next->sibling = NULL; |
515 | for (next = first; next; next = next->sibling) |
516 | next->parent = new; |
517 | |
518 | if (parent->child == first) { |
519 | parent->child = new; |
520 | } else { |
521 | next = parent->child; |
522 | while (next->sibling != first) |
523 | next = next->sibling; |
524 | next->sibling = new; |
525 | } |
526 | return NULL; |
527 | } |
528 | |
529 | /** |
530 | * insert_resource_conflict - Inserts resource in the resource tree |
531 | * @parent: parent of the new resource |
532 | * @new: new resource to insert |
533 | * |
534 | * Returns 0 on success, conflict resource if the resource can't be inserted. |
535 | * |
536 | * This function is equivalent to request_resource_conflict when no conflict |
537 | * happens. If a conflict happens, and the conflicting resources |
538 | * entirely fit within the range of the new resource, then the new |
539 | * resource is inserted and the conflicting resources become children of |
540 | * the new resource. |
541 | */ |
542 | struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) |
543 | { |
544 | struct resource *conflict; |
545 | |
546 | write_lock(&resource_lock); |
547 | conflict = __insert_resource(parent, new); |
548 | write_unlock(&resource_lock); |
549 | return conflict; |
550 | } |
551 | |
552 | /** |
553 | * insert_resource - Inserts a resource in the resource tree |
554 | * @parent: parent of the new resource |
555 | * @new: new resource to insert |
556 | * |
557 | * Returns 0 on success, -EBUSY if the resource can't be inserted. |
558 | */ |
559 | int insert_resource(struct resource *parent, struct resource *new) |
560 | { |
561 | struct resource *conflict; |
562 | |
563 | conflict = insert_resource_conflict(parent, new); |
564 | return conflict ? -EBUSY : 0; |
565 | } |
566 | |
567 | /** |
568 | * insert_resource_expand_to_fit - Insert a resource into the resource tree |
569 | * @root: root resource descriptor |
570 | * @new: new resource to insert |
571 | * |
572 | * Insert a resource into the resource tree, possibly expanding it in order |
573 | * to make it encompass any conflicting resources. |
574 | */ |
575 | void insert_resource_expand_to_fit(struct resource *root, struct resource *new) |
576 | { |
577 | if (new->parent) |
578 | return; |
579 | |
580 | write_lock(&resource_lock); |
581 | for (;;) { |
582 | struct resource *conflict; |
583 | |
584 | conflict = __insert_resource(root, new); |
585 | if (!conflict) |
586 | break; |
587 | if (conflict == root) |
588 | break; |
589 | |
590 | /* Ok, expand resource to cover the conflict, then try again .. */ |
591 | if (conflict->start < new->start) |
592 | new->start = conflict->start; |
593 | if (conflict->end > new->end) |
594 | new->end = conflict->end; |
595 | |
596 | printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); |
597 | } |
598 | write_unlock(&resource_lock); |
599 | } |
600 | |
601 | /** |
602 | * adjust_resource - modify a resource's start and size |
603 | * @res: resource to modify |
604 | * @start: new start value |
605 | * @size: new size |
606 | * |
607 | * Given an existing resource, change its start and size to match the |
608 | * arguments. Returns 0 on success, -EBUSY if it can't fit. |
609 | * Existing children of the resource are assumed to be immutable. |
610 | */ |
611 | int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) |
612 | { |
613 | struct resource *tmp, *parent = res->parent; |
614 | resource_size_t end = start + size - 1; |
615 | int result = -EBUSY; |
616 | |
617 | write_lock(&resource_lock); |
618 | |
619 | if ((start < parent->start) || (end > parent->end)) |
620 | goto out; |
621 | |
622 | for (tmp = res->child; tmp; tmp = tmp->sibling) { |
623 | if ((tmp->start < start) || (tmp->end > end)) |
624 | goto out; |
625 | } |
626 | |
627 | if (res->sibling && (res->sibling->start <= end)) |
628 | goto out; |
629 | |
630 | tmp = parent->child; |
631 | if (tmp != res) { |
632 | while (tmp->sibling != res) |
633 | tmp = tmp->sibling; |
634 | if (start <= tmp->end) |
635 | goto out; |
636 | } |
637 | |
638 | res->start = start; |
639 | res->end = end; |
640 | result = 0; |
641 | |
642 | out: |
643 | write_unlock(&resource_lock); |
644 | return result; |
645 | } |
646 | |
647 | static void __init __reserve_region_with_split(struct resource *root, |
648 | resource_size_t start, resource_size_t end, |
649 | const char *name) |
650 | { |
651 | struct resource *parent = root; |
652 | struct resource *conflict; |
653 | struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); |
654 | |
655 | if (!res) |
656 | return; |
657 | |
658 | res->name = name; |
659 | res->start = start; |
660 | res->end = end; |
661 | res->flags = IORESOURCE_BUSY; |
662 | |
663 | conflict = __request_resource(parent, res); |
664 | if (!conflict) |
665 | return; |
666 | |
667 | /* failed, split and try again */ |
668 | kfree(res); |
669 | |
670 | /* conflict covered whole area */ |
671 | if (conflict->start <= start && conflict->end >= end) |
672 | return; |
673 | |
674 | if (conflict->start > start) |
675 | __reserve_region_with_split(root, start, conflict->start-1, name); |
676 | if (conflict->end < end) |
677 | __reserve_region_with_split(root, conflict->end+1, end, name); |
678 | } |
679 | |
680 | void __init reserve_region_with_split(struct resource *root, |
681 | resource_size_t start, resource_size_t end, |
682 | const char *name) |
683 | { |
684 | write_lock(&resource_lock); |
685 | __reserve_region_with_split(root, start, end, name); |
686 | write_unlock(&resource_lock); |
687 | } |
688 | |
689 | EXPORT_SYMBOL(adjust_resource); |
690 | |
691 | /** |
692 | * resource_alignment - calculate resource's alignment |
693 | * @res: resource pointer |
694 | * |
695 | * Returns alignment on success, 0 (invalid alignment) on failure. |
696 | */ |
697 | resource_size_t resource_alignment(struct resource *res) |
698 | { |
699 | switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { |
700 | case IORESOURCE_SIZEALIGN: |
701 | return resource_size(res); |
702 | case IORESOURCE_STARTALIGN: |
703 | return res->start; |
704 | default: |
705 | return 0; |
706 | } |
707 | } |
708 | |
709 | /* |
710 | * This is compatibility stuff for IO resources. |
711 | * |
712 | * Note how this, unlike the above, knows about |
713 | * the IO flag meanings (busy etc). |
714 | * |
715 | * request_region creates a new busy region. |
716 | * |
717 | * check_region returns non-zero if the area is already busy. |
718 | * |
719 | * release_region releases a matching busy region. |
720 | */ |
721 | |
722 | static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); |
723 | |
724 | /** |
725 | * __request_region - create a new busy resource region |
726 | * @parent: parent resource descriptor |
727 | * @start: resource start address |
728 | * @n: resource region size |
729 | * @name: reserving caller's ID string |
730 | * @flags: IO resource flags |
731 | */ |
732 | struct resource * __request_region(struct resource *parent, |
733 | resource_size_t start, resource_size_t n, |
734 | const char *name, int flags) |
735 | { |
736 | DECLARE_WAITQUEUE(wait, current); |
737 | struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); |
738 | |
739 | if (!res) |
740 | return NULL; |
741 | |
742 | res->name = name; |
743 | res->start = start; |
744 | res->end = start + n - 1; |
745 | res->flags = IORESOURCE_BUSY; |
746 | res->flags |= flags; |
747 | |
748 | write_lock(&resource_lock); |
749 | |
750 | for (;;) { |
751 | struct resource *conflict; |
752 | |
753 | conflict = __request_resource(parent, res); |
754 | if (!conflict) |
755 | break; |
756 | if (conflict != parent) { |
757 | parent = conflict; |
758 | if (!(conflict->flags & IORESOURCE_BUSY)) |
759 | continue; |
760 | } |
761 | if (conflict->flags & flags & IORESOURCE_MUXED) { |
762 | add_wait_queue(&muxed_resource_wait, &wait); |
763 | write_unlock(&resource_lock); |
764 | set_current_state(TASK_UNINTERRUPTIBLE); |
765 | schedule(); |
766 | remove_wait_queue(&muxed_resource_wait, &wait); |
767 | write_lock(&resource_lock); |
768 | continue; |
769 | } |
770 | /* Uhhuh, that didn't work out.. */ |
771 | kfree(res); |
772 | res = NULL; |
773 | break; |
774 | } |
775 | write_unlock(&resource_lock); |
776 | return res; |
777 | } |
778 | EXPORT_SYMBOL(__request_region); |
779 | |
780 | /** |
781 | * __check_region - check if a resource region is busy or free |
782 | * @parent: parent resource descriptor |
783 | * @start: resource start address |
784 | * @n: resource region size |
785 | * |
786 | * Returns 0 if the region is free at the moment it is checked, |
787 | * returns %-EBUSY if the region is busy. |
788 | * |
789 | * NOTE: |
790 | * This function is deprecated because its use is racy. |
791 | * Even if it returns 0, a subsequent call to request_region() |
792 | * may fail because another driver etc. just allocated the region. |
793 | * Do NOT use it. It will be removed from the kernel. |
794 | */ |
795 | int __check_region(struct resource *parent, resource_size_t start, |
796 | resource_size_t n) |
797 | { |
798 | struct resource * res; |
799 | |
800 | res = __request_region(parent, start, n, "check-region", 0); |
801 | if (!res) |
802 | return -EBUSY; |
803 | |
804 | release_resource(res); |
805 | kfree(res); |
806 | return 0; |
807 | } |
808 | EXPORT_SYMBOL(__check_region); |
809 | |
810 | /** |
811 | * __release_region - release a previously reserved resource region |
812 | * @parent: parent resource descriptor |
813 | * @start: resource start address |
814 | * @n: resource region size |
815 | * |
816 | * The described resource region must match a currently busy region. |
817 | */ |
818 | void __release_region(struct resource *parent, resource_size_t start, |
819 | resource_size_t n) |
820 | { |
821 | struct resource **p; |
822 | resource_size_t end; |
823 | |
824 | p = &parent->child; |
825 | end = start + n - 1; |
826 | |
827 | write_lock(&resource_lock); |
828 | |
829 | for (;;) { |
830 | struct resource *res = *p; |
831 | |
832 | if (!res) |
833 | break; |
834 | if (res->start <= start && res->end >= end) { |
835 | if (!(res->flags & IORESOURCE_BUSY)) { |
836 | p = &res->child; |
837 | continue; |
838 | } |
839 | if (res->start != start || res->end != end) |
840 | break; |
841 | *p = res->sibling; |
842 | write_unlock(&resource_lock); |
843 | if (res->flags & IORESOURCE_MUXED) |
844 | wake_up(&muxed_resource_wait); |
845 | kfree(res); |
846 | return; |
847 | } |
848 | p = &res->sibling; |
849 | } |
850 | |
851 | write_unlock(&resource_lock); |
852 | |
853 | printk(KERN_WARNING "Trying to free nonexistent resource " |
854 | "<%016llx-%016llx>\n", (unsigned long long)start, |
855 | (unsigned long long)end); |
856 | } |
857 | EXPORT_SYMBOL(__release_region); |
858 | |
859 | /* |
860 | * Managed region resource |
861 | */ |
862 | struct region_devres { |
863 | struct resource *parent; |
864 | resource_size_t start; |
865 | resource_size_t n; |
866 | }; |
867 | |
868 | static void devm_region_release(struct device *dev, void *res) |
869 | { |
870 | struct region_devres *this = res; |
871 | |
872 | __release_region(this->parent, this->start, this->n); |
873 | } |
874 | |
875 | static int devm_region_match(struct device *dev, void *res, void *match_data) |
876 | { |
877 | struct region_devres *this = res, *match = match_data; |
878 | |
879 | return this->parent == match->parent && |
880 | this->start == match->start && this->n == match->n; |
881 | } |
882 | |
883 | struct resource * __devm_request_region(struct device *dev, |
884 | struct resource *parent, resource_size_t start, |
885 | resource_size_t n, const char *name) |
886 | { |
887 | struct region_devres *dr = NULL; |
888 | struct resource *res; |
889 | |
890 | dr = devres_alloc(devm_region_release, sizeof(struct region_devres), |
891 | GFP_KERNEL); |
892 | if (!dr) |
893 | return NULL; |
894 | |
895 | dr->parent = parent; |
896 | dr->start = start; |
897 | dr->n = n; |
898 | |
899 | res = __request_region(parent, start, n, name, 0); |
900 | if (res) |
901 | devres_add(dev, dr); |
902 | else |
903 | devres_free(dr); |
904 | |
905 | return res; |
906 | } |
907 | EXPORT_SYMBOL(__devm_request_region); |
908 | |
909 | void __devm_release_region(struct device *dev, struct resource *parent, |
910 | resource_size_t start, resource_size_t n) |
911 | { |
912 | struct region_devres match_data = { parent, start, n }; |
913 | |
914 | __release_region(parent, start, n); |
915 | WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, |
916 | &match_data)); |
917 | } |
918 | EXPORT_SYMBOL(__devm_release_region); |
919 | |
920 | /* |
921 | * Called from init/main.c to reserve IO ports. |
922 | */ |
923 | #define MAXRESERVE 4 |
924 | static int __init reserve_setup(char *str) |
925 | { |
926 | static int reserved; |
927 | static struct resource reserve[MAXRESERVE]; |
928 | |
929 | for (;;) { |
930 | unsigned int io_start, io_num; |
931 | int x = reserved; |
932 | |
933 | if (get_option (&str, &io_start) != 2) |
934 | break; |
935 | if (get_option (&str, &io_num) == 0) |
936 | break; |
937 | if (x < MAXRESERVE) { |
938 | struct resource *res = reserve + x; |
939 | res->name = "reserved"; |
940 | res->start = io_start; |
941 | res->end = io_start + io_num - 1; |
942 | res->flags = IORESOURCE_BUSY; |
943 | res->child = NULL; |
944 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) |
945 | reserved = x+1; |
946 | } |
947 | } |
948 | return 1; |
949 | } |
950 | |
951 | __setup("reserve=", reserve_setup); |
952 | |
953 | /* |
954 | * Check if the requested addr and size spans more than any slot in the |
955 | * iomem resource tree. |
956 | */ |
957 | int iomem_map_sanity_check(resource_size_t addr, unsigned long size) |
958 | { |
959 | struct resource *p = &iomem_resource; |
960 | int err = 0; |
961 | loff_t l; |
962 | |
963 | read_lock(&resource_lock); |
964 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { |
965 | /* |
966 | * We can probably skip the resources without |
967 | * IORESOURCE_IO attribute? |
968 | */ |
969 | if (p->start >= addr + size) |
970 | continue; |
971 | if (p->end < addr) |
972 | continue; |
973 | if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && |
974 | PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) |
975 | continue; |
976 | /* |
977 | * if a resource is "BUSY", it's not a hardware resource |
978 | * but a driver mapping of such a resource; we don't want |
979 | * to warn for those; some drivers legitimately map only |
980 | * partial hardware resources. (example: vesafb) |
981 | */ |
982 | if (p->flags & IORESOURCE_BUSY) |
983 | continue; |
984 | |
985 | printk(KERN_WARNING "resource map sanity check conflict: " |
986 | "0x%llx 0x%llx 0x%llx 0x%llx %s\n", |
987 | (unsigned long long)addr, |
988 | (unsigned long long)(addr + size - 1), |
989 | (unsigned long long)p->start, |
990 | (unsigned long long)p->end, |
991 | p->name); |
992 | err = -1; |
993 | break; |
994 | } |
995 | read_unlock(&resource_lock); |
996 | |
997 | return err; |
998 | } |
999 | |
1000 | #ifdef CONFIG_STRICT_DEVMEM |
1001 | static int strict_iomem_checks = 1; |
1002 | #else |
1003 | static int strict_iomem_checks; |
1004 | #endif |
1005 | |
1006 | /* |
1007 | * check if an address is reserved in the iomem resource tree |
1008 | * returns 1 if reserved, 0 if not reserved. |
1009 | */ |
1010 | int iomem_is_exclusive(u64 addr) |
1011 | { |
1012 | struct resource *p = &iomem_resource; |
1013 | int err = 0; |
1014 | loff_t l; |
1015 | int size = PAGE_SIZE; |
1016 | |
1017 | if (!strict_iomem_checks) |
1018 | return 0; |
1019 | |
1020 | addr = addr & PAGE_MASK; |
1021 | |
1022 | read_lock(&resource_lock); |
1023 | for (p = p->child; p ; p = r_next(NULL, p, &l)) { |
1024 | /* |
1025 | * We can probably skip the resources without |
1026 | * IORESOURCE_IO attribute? |
1027 | */ |
1028 | if (p->start >= addr + size) |
1029 | break; |
1030 | if (p->end < addr) |
1031 | continue; |
1032 | if (p->flags & IORESOURCE_BUSY && |
1033 | p->flags & IORESOURCE_EXCLUSIVE) { |
1034 | err = 1; |
1035 | break; |
1036 | } |
1037 | } |
1038 | read_unlock(&resource_lock); |
1039 | |
1040 | return err; |
1041 | } |
1042 | |
1043 | static int __init strict_iomem(char *str) |
1044 | { |
1045 | if (strstr(str, "relaxed")) |
1046 | strict_iomem_checks = 0; |
1047 | if (strstr(str, "strict")) |
1048 | strict_iomem_checks = 1; |
1049 | return 1; |
1050 | } |
1051 | |
1052 | __setup("iomem=", strict_iomem); |
1053 |
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