2 * linux/kernel/resource.c
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
7 * Arbitrary resource management.
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>
17 #include <linux/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/device.h>
23 struct resource ioport_resource = {
26 .end = IO_SPACE_LIMIT,
27 .flags = IORESOURCE_IO,
29 EXPORT_SYMBOL(ioport_resource);
31 struct resource iomem_resource = {
35 .flags = IORESOURCE_MEM,
37 EXPORT_SYMBOL(iomem_resource);
39 static DEFINE_RWLOCK(resource_lock);
43 enum { MAX_IORES_LEVEL = 5 };
45 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
47 struct resource *p = v;
51 while (!p->sibling && p->parent)
56 static void *r_start(struct seq_file *m, loff_t *pos)
57 __acquires(resource_lock)
59 struct resource *p = m->private;
61 read_lock(&resource_lock);
62 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
67 static void r_stop(struct seq_file *m, void *v)
68 __releases(resource_lock)
70 read_unlock(&resource_lock);
73 static int r_show(struct seq_file *m, void *v)
75 struct resource *root = m->private;
76 struct resource *r = v, *p;
77 int width = root->end < 0x10000 ? 4 : 8;
80 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
81 if (p->parent == root)
83 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
85 width, (unsigned long long) r->start,
86 width, (unsigned long long) r->end,
87 r->name ? r->name : "<BAD>");
91 static const struct seq_operations resource_op = {
98 static int ioports_open(struct inode *inode, struct file *file)
100 int res = seq_open(file, &resource_op);
102 struct seq_file *m = file->private_data;
103 m->private = &ioport_resource;
108 static int iomem_open(struct inode *inode, struct file *file)
110 int res = seq_open(file, &resource_op);
112 struct seq_file *m = file->private_data;
113 m->private = &iomem_resource;
118 static const struct file_operations proc_ioports_operations = {
119 .open = ioports_open,
122 .release = seq_release,
125 static const struct file_operations proc_iomem_operations = {
129 .release = seq_release,
132 static int __init ioresources_init(void)
134 proc_create("ioports", 0, NULL, &proc_ioports_operations);
135 proc_create("iomem", 0, NULL, &proc_iomem_operations);
138 __initcall(ioresources_init);
140 #endif /* CONFIG_PROC_FS */
142 /* Return the conflict entry if you can't request it */
143 static struct resource * __request_resource(struct resource *root, struct resource *new)
145 resource_size_t start = new->start;
146 resource_size_t end = new->end;
147 struct resource *tmp, **p;
151 if (start < root->start)
158 if (!tmp || tmp->start > end) {
165 if (tmp->end < start)
171 static int __release_resource(struct resource *old)
173 struct resource *tmp, **p;
175 p = &old->parent->child;
191 * request_resource - request and reserve an I/O or memory resource
192 * @root: root resource descriptor
193 * @new: resource descriptor desired by caller
195 * Returns 0 for success, negative error code on error.
197 int request_resource(struct resource *root, struct resource *new)
199 struct resource *conflict;
201 write_lock(&resource_lock);
202 conflict = __request_resource(root, new);
203 write_unlock(&resource_lock);
204 return conflict ? -EBUSY : 0;
207 EXPORT_SYMBOL(request_resource);
210 * release_resource - release a previously reserved resource
211 * @old: resource pointer
213 int release_resource(struct resource *old)
217 write_lock(&resource_lock);
218 retval = __release_resource(old);
219 write_unlock(&resource_lock);
223 EXPORT_SYMBOL(release_resource);
225 #if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
227 * Finds the lowest memory reosurce exists within [res->start.res->end)
228 * the caller must specify res->start, res->end, res->flags.
229 * If found, returns 0, res is overwritten, if not found, returns -1.
231 static int find_next_system_ram(struct resource *res)
233 resource_size_t start, end;
240 BUG_ON(start >= end);
242 read_lock(&resource_lock);
243 for (p = iomem_resource.child; p ; p = p->sibling) {
244 /* system ram is just marked as IORESOURCE_MEM */
245 if (p->flags != res->flags)
247 if (p->start > end) {
251 if ((p->end >= start) && (p->start < end))
254 read_unlock(&resource_lock);
258 if (res->start < p->start)
259 res->start = p->start;
260 if (res->end > p->end)
265 walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
266 int (*func)(unsigned long, unsigned long, void *))
269 unsigned long pfn, len;
272 res.start = (u64) start_pfn << PAGE_SHIFT;
273 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
274 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
276 while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
277 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
278 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
279 ret = (*func)(pfn, len, arg);
282 res.start = res.end + 1;
291 * Find empty slot in the resource tree given range and alignment.
293 static int find_resource(struct resource *root, struct resource *new,
294 resource_size_t size, resource_size_t min,
295 resource_size_t max, resource_size_t align,
296 void (*alignf)(void *, struct resource *,
297 resource_size_t, resource_size_t),
300 struct resource *this = root->child;
302 new->start = root->start;
304 * Skip past an allocated resource that starts at 0, since the assignment
305 * of this->start - 1 to new->end below would cause an underflow.
307 if (this && this->start == 0) {
308 new->start = this->end + 1;
309 this = this->sibling;
313 new->end = this->start - 1;
315 new->end = root->end;
316 if (new->start < min)
320 new->start = ALIGN(new->start, align);
322 alignf(alignf_data, new, size, align);
323 if (new->start < new->end && new->end - new->start >= size - 1) {
324 new->end = new->start + size - 1;
329 new->start = this->end + 1;
330 this = this->sibling;
336 * allocate_resource - allocate empty slot in the resource tree given range & alignment
337 * @root: root resource descriptor
338 * @new: resource descriptor desired by caller
339 * @size: requested resource region size
340 * @min: minimum size to allocate
341 * @max: maximum size to allocate
342 * @align: alignment requested, in bytes
343 * @alignf: alignment function, optional, called if not NULL
344 * @alignf_data: arbitrary data to pass to the @alignf function
346 int allocate_resource(struct resource *root, struct resource *new,
347 resource_size_t size, resource_size_t min,
348 resource_size_t max, resource_size_t align,
349 void (*alignf)(void *, struct resource *,
350 resource_size_t, resource_size_t),
355 write_lock(&resource_lock);
356 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
357 if (err >= 0 && __request_resource(root, new))
359 write_unlock(&resource_lock);
363 EXPORT_SYMBOL(allocate_resource);
366 * Insert a resource into the resource tree. If successful, return NULL,
367 * otherwise return the conflicting resource (compare to __request_resource())
369 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
371 struct resource *first, *next;
373 for (;; parent = first) {
374 first = __request_resource(parent, new);
381 if ((first->start > new->start) || (first->end < new->end))
383 if ((first->start == new->start) && (first->end == new->end))
387 for (next = first; ; next = next->sibling) {
388 /* Partial overlap? Bad, and unfixable */
389 if (next->start < new->start || next->end > new->end)
393 if (next->sibling->start > new->end)
397 new->parent = parent;
398 new->sibling = next->sibling;
401 next->sibling = NULL;
402 for (next = first; next; next = next->sibling)
405 if (parent->child == first) {
408 next = parent->child;
409 while (next->sibling != first)
410 next = next->sibling;
417 * insert_resource - Inserts a resource in the resource tree
418 * @parent: parent of the new resource
419 * @new: new resource to insert
421 * Returns 0 on success, -EBUSY if the resource can't be inserted.
423 * This function is equivalent to request_resource when no conflict
424 * happens. If a conflict happens, and the conflicting resources
425 * entirely fit within the range of the new resource, then the new
426 * resource is inserted and the conflicting resources become children of
429 int insert_resource(struct resource *parent, struct resource *new)
431 struct resource *conflict;
433 write_lock(&resource_lock);
434 conflict = __insert_resource(parent, new);
435 write_unlock(&resource_lock);
436 return conflict ? -EBUSY : 0;
440 * insert_resource_expand_to_fit - Insert a resource into the resource tree
441 * @root: root resource descriptor
442 * @new: new resource to insert
444 * Insert a resource into the resource tree, possibly expanding it in order
445 * to make it encompass any conflicting resources.
447 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
452 write_lock(&resource_lock);
454 struct resource *conflict;
456 conflict = __insert_resource(root, new);
459 if (conflict == root)
462 /* Ok, expand resource to cover the conflict, then try again .. */
463 if (conflict->start < new->start)
464 new->start = conflict->start;
465 if (conflict->end > new->end)
466 new->end = conflict->end;
468 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
470 write_unlock(&resource_lock);
474 * adjust_resource - modify a resource's start and size
475 * @res: resource to modify
476 * @start: new start value
479 * Given an existing resource, change its start and size to match the
480 * arguments. Returns 0 on success, -EBUSY if it can't fit.
481 * Existing children of the resource are assumed to be immutable.
483 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
485 struct resource *tmp, *parent = res->parent;
486 resource_size_t end = start + size - 1;
489 write_lock(&resource_lock);
491 if ((start < parent->start) || (end > parent->end))
494 for (tmp = res->child; tmp; tmp = tmp->sibling) {
495 if ((tmp->start < start) || (tmp->end > end))
499 if (res->sibling && (res->sibling->start <= end))
504 while (tmp->sibling != res)
506 if (start <= tmp->end)
515 write_unlock(&resource_lock);
519 EXPORT_SYMBOL(adjust_resource);
522 * resource_alignment - calculate resource's alignment
523 * @res: resource pointer
525 * Returns alignment on success, 0 (invalid alignment) on failure.
527 resource_size_t resource_alignment(struct resource *res)
529 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
530 case IORESOURCE_SIZEALIGN:
531 return resource_size(res);
532 case IORESOURCE_STARTALIGN:
540 * This is compatibility stuff for IO resources.
542 * Note how this, unlike the above, knows about
543 * the IO flag meanings (busy etc).
545 * request_region creates a new busy region.
547 * check_region returns non-zero if the area is already busy.
549 * release_region releases a matching busy region.
553 * __request_region - create a new busy resource region
554 * @parent: parent resource descriptor
555 * @start: resource start address
556 * @n: resource region size
557 * @name: reserving caller's ID string
559 struct resource * __request_region(struct resource *parent,
560 resource_size_t start, resource_size_t n,
563 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
568 res->end = start + n - 1;
569 res->flags = IORESOURCE_BUSY;
571 write_lock(&resource_lock);
574 struct resource *conflict;
576 conflict = __request_resource(parent, res);
579 if (conflict != parent) {
581 if (!(conflict->flags & IORESOURCE_BUSY))
585 /* Uhhuh, that didn't work out.. */
590 write_unlock(&resource_lock);
594 EXPORT_SYMBOL(__request_region);
597 * __check_region - check if a resource region is busy or free
598 * @parent: parent resource descriptor
599 * @start: resource start address
600 * @n: resource region size
602 * Returns 0 if the region is free at the moment it is checked,
603 * returns %-EBUSY if the region is busy.
606 * This function is deprecated because its use is racy.
607 * Even if it returns 0, a subsequent call to request_region()
608 * may fail because another driver etc. just allocated the region.
609 * Do NOT use it. It will be removed from the kernel.
611 int __check_region(struct resource *parent, resource_size_t start,
614 struct resource * res;
616 res = __request_region(parent, start, n, "check-region");
620 release_resource(res);
624 EXPORT_SYMBOL(__check_region);
627 * __release_region - release a previously reserved resource region
628 * @parent: parent resource descriptor
629 * @start: resource start address
630 * @n: resource region size
632 * The described resource region must match a currently busy region.
634 void __release_region(struct resource *parent, resource_size_t start,
643 write_lock(&resource_lock);
646 struct resource *res = *p;
650 if (res->start <= start && res->end >= end) {
651 if (!(res->flags & IORESOURCE_BUSY)) {
655 if (res->start != start || res->end != end)
658 write_unlock(&resource_lock);
665 write_unlock(&resource_lock);
667 printk(KERN_WARNING "Trying to free nonexistent resource "
668 "<%016llx-%016llx>\n", (unsigned long long)start,
669 (unsigned long long)end);
671 EXPORT_SYMBOL(__release_region);
674 * Managed region resource
676 struct region_devres {
677 struct resource *parent;
678 resource_size_t start;
682 static void devm_region_release(struct device *dev, void *res)
684 struct region_devres *this = res;
686 __release_region(this->parent, this->start, this->n);
689 static int devm_region_match(struct device *dev, void *res, void *match_data)
691 struct region_devres *this = res, *match = match_data;
693 return this->parent == match->parent &&
694 this->start == match->start && this->n == match->n;
697 struct resource * __devm_request_region(struct device *dev,
698 struct resource *parent, resource_size_t start,
699 resource_size_t n, const char *name)
701 struct region_devres *dr = NULL;
702 struct resource *res;
704 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
713 res = __request_region(parent, start, n, name);
721 EXPORT_SYMBOL(__devm_request_region);
723 void __devm_release_region(struct device *dev, struct resource *parent,
724 resource_size_t start, resource_size_t n)
726 struct region_devres match_data = { parent, start, n };
728 __release_region(parent, start, n);
729 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
732 EXPORT_SYMBOL(__devm_release_region);
735 * Called from init/main.c to reserve IO ports.
738 static int __init reserve_setup(char *str)
741 static struct resource reserve[MAXRESERVE];
744 int io_start, io_num;
747 if (get_option (&str, &io_start) != 2)
749 if (get_option (&str, &io_num) == 0)
751 if (x < MAXRESERVE) {
752 struct resource *res = reserve + x;
753 res->name = "reserved";
754 res->start = io_start;
755 res->end = io_start + io_num - 1;
756 res->flags = IORESOURCE_BUSY;
758 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
765 __setup("reserve=", reserve_setup);