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>
20 #include <linux/pfn.h>
24 struct resource ioport_resource = {
27 .end = IO_SPACE_LIMIT,
28 .flags = IORESOURCE_IO,
30 EXPORT_SYMBOL(ioport_resource);
32 struct resource iomem_resource = {
36 .flags = IORESOURCE_MEM,
38 EXPORT_SYMBOL(iomem_resource);
40 static DEFINE_RWLOCK(resource_lock);
42 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
44 struct resource *p = v;
48 while (!p->sibling && p->parent)
55 enum { MAX_IORES_LEVEL = 5 };
57 static void *r_start(struct seq_file *m, loff_t *pos)
58 __acquires(resource_lock)
60 struct resource *p = m->private;
62 read_lock(&resource_lock);
63 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
68 static void r_stop(struct seq_file *m, void *v)
69 __releases(resource_lock)
71 read_unlock(&resource_lock);
74 static int r_show(struct seq_file *m, void *v)
76 struct resource *root = m->private;
77 struct resource *r = v, *p;
78 int width = root->end < 0x10000 ? 4 : 8;
81 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
82 if (p->parent == root)
84 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
86 width, (unsigned long long) r->start,
87 width, (unsigned long long) r->end,
88 r->name ? r->name : "<BAD>");
92 static const struct seq_operations resource_op = {
99 static int ioports_open(struct inode *inode, struct file *file)
101 int res = seq_open(file, &resource_op);
103 struct seq_file *m = file->private_data;
104 m->private = &ioport_resource;
109 static int iomem_open(struct inode *inode, struct file *file)
111 int res = seq_open(file, &resource_op);
113 struct seq_file *m = file->private_data;
114 m->private = &iomem_resource;
119 static const struct file_operations proc_ioports_operations = {
120 .open = ioports_open,
123 .release = seq_release,
126 static const struct file_operations proc_iomem_operations = {
130 .release = seq_release,
133 static int __init ioresources_init(void)
135 proc_create("ioports", 0, NULL, &proc_ioports_operations);
136 proc_create("iomem", 0, NULL, &proc_iomem_operations);
139 __initcall(ioresources_init);
141 #endif /* CONFIG_PROC_FS */
143 /* Return the conflict entry if you can't request it */
144 static struct resource * __request_resource(struct resource *root, struct resource *new)
146 resource_size_t start = new->start;
147 resource_size_t end = new->end;
148 struct resource *tmp, **p;
152 if (start < root->start)
159 if (!tmp || tmp->start > end) {
166 if (tmp->end < start)
172 static int __release_resource(struct resource *old)
174 struct resource *tmp, **p;
176 p = &old->parent->child;
192 * request_resource - request and reserve an I/O or memory resource
193 * @root: root resource descriptor
194 * @new: resource descriptor desired by caller
196 * Returns 0 for success, negative error code on error.
198 int request_resource(struct resource *root, struct resource *new)
200 struct resource *conflict;
202 write_lock(&resource_lock);
203 conflict = __request_resource(root, new);
204 write_unlock(&resource_lock);
205 return conflict ? -EBUSY : 0;
208 EXPORT_SYMBOL(request_resource);
211 * release_resource - release a previously reserved resource
212 * @old: resource pointer
214 int release_resource(struct resource *old)
218 write_lock(&resource_lock);
219 retval = __release_resource(old);
220 write_unlock(&resource_lock);
224 EXPORT_SYMBOL(release_resource);
226 #if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
228 * Finds the lowest memory reosurce exists within [res->start.res->end)
229 * the caller must specify res->start, res->end, res->flags.
230 * If found, returns 0, res is overwritten, if not found, returns -1.
232 static int find_next_system_ram(struct resource *res)
234 resource_size_t start, end;
241 BUG_ON(start >= end);
243 read_lock(&resource_lock);
244 for (p = iomem_resource.child; p ; p = p->sibling) {
245 /* system ram is just marked as IORESOURCE_MEM */
246 if (p->flags != res->flags)
248 if (p->start > end) {
252 if ((p->end >= start) && (p->start < end))
255 read_unlock(&resource_lock);
259 if (res->start < p->start)
260 res->start = p->start;
261 if (res->end > p->end)
266 walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
267 int (*func)(unsigned long, unsigned long, void *))
270 unsigned long pfn, len;
273 res.start = (u64) start_pfn << PAGE_SHIFT;
274 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
275 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
277 while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
278 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
279 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
280 ret = (*func)(pfn, len, arg);
283 res.start = res.end + 1;
292 * Find empty slot in the resource tree given range and alignment.
294 static int find_resource(struct resource *root, struct resource *new,
295 resource_size_t size, resource_size_t min,
296 resource_size_t max, resource_size_t align,
297 void (*alignf)(void *, struct resource *,
298 resource_size_t, resource_size_t),
301 struct resource *this = root->child;
303 new->start = root->start;
305 * Skip past an allocated resource that starts at 0, since the assignment
306 * of this->start - 1 to new->end below would cause an underflow.
308 if (this && this->start == 0) {
309 new->start = this->end + 1;
310 this = this->sibling;
314 new->end = this->start - 1;
316 new->end = root->end;
317 if (new->start < min)
321 new->start = ALIGN(new->start, align);
323 alignf(alignf_data, new, size, align);
324 if (new->start < new->end && new->end - new->start >= size - 1) {
325 new->end = new->start + size - 1;
330 new->start = this->end + 1;
331 this = this->sibling;
337 * allocate_resource - allocate empty slot in the resource tree given range & alignment
338 * @root: root resource descriptor
339 * @new: resource descriptor desired by caller
340 * @size: requested resource region size
341 * @min: minimum size to allocate
342 * @max: maximum size to allocate
343 * @align: alignment requested, in bytes
344 * @alignf: alignment function, optional, called if not NULL
345 * @alignf_data: arbitrary data to pass to the @alignf function
347 int allocate_resource(struct resource *root, struct resource *new,
348 resource_size_t size, resource_size_t min,
349 resource_size_t max, resource_size_t align,
350 void (*alignf)(void *, struct resource *,
351 resource_size_t, resource_size_t),
356 write_lock(&resource_lock);
357 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
358 if (err >= 0 && __request_resource(root, new))
360 write_unlock(&resource_lock);
364 EXPORT_SYMBOL(allocate_resource);
367 * Insert a resource into the resource tree. If successful, return NULL,
368 * otherwise return the conflicting resource (compare to __request_resource())
370 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
372 struct resource *first, *next;
374 for (;; parent = first) {
375 first = __request_resource(parent, new);
382 if ((first->start > new->start) || (first->end < new->end))
384 if ((first->start == new->start) && (first->end == new->end))
388 for (next = first; ; next = next->sibling) {
389 /* Partial overlap? Bad, and unfixable */
390 if (next->start < new->start || next->end > new->end)
394 if (next->sibling->start > new->end)
398 new->parent = parent;
399 new->sibling = next->sibling;
402 next->sibling = NULL;
403 for (next = first; next; next = next->sibling)
406 if (parent->child == first) {
409 next = parent->child;
410 while (next->sibling != first)
411 next = next->sibling;
418 * insert_resource - Inserts a resource in the resource tree
419 * @parent: parent of the new resource
420 * @new: new resource to insert
422 * Returns 0 on success, -EBUSY if the resource can't be inserted.
424 * This function is equivalent to request_resource when no conflict
425 * happens. If a conflict happens, and the conflicting resources
426 * entirely fit within the range of the new resource, then the new
427 * resource is inserted and the conflicting resources become children of
430 int insert_resource(struct resource *parent, struct resource *new)
432 struct resource *conflict;
434 write_lock(&resource_lock);
435 conflict = __insert_resource(parent, new);
436 write_unlock(&resource_lock);
437 return conflict ? -EBUSY : 0;
441 * insert_resource_expand_to_fit - Insert a resource into the resource tree
442 * @root: root resource descriptor
443 * @new: new resource to insert
445 * Insert a resource into the resource tree, possibly expanding it in order
446 * to make it encompass any conflicting resources.
448 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
453 write_lock(&resource_lock);
455 struct resource *conflict;
457 conflict = __insert_resource(root, new);
460 if (conflict == root)
463 /* Ok, expand resource to cover the conflict, then try again .. */
464 if (conflict->start < new->start)
465 new->start = conflict->start;
466 if (conflict->end > new->end)
467 new->end = conflict->end;
469 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
471 write_unlock(&resource_lock);
475 * adjust_resource - modify a resource's start and size
476 * @res: resource to modify
477 * @start: new start value
480 * Given an existing resource, change its start and size to match the
481 * arguments. Returns 0 on success, -EBUSY if it can't fit.
482 * Existing children of the resource are assumed to be immutable.
484 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
486 struct resource *tmp, *parent = res->parent;
487 resource_size_t end = start + size - 1;
490 write_lock(&resource_lock);
492 if ((start < parent->start) || (end > parent->end))
495 for (tmp = res->child; tmp; tmp = tmp->sibling) {
496 if ((tmp->start < start) || (tmp->end > end))
500 if (res->sibling && (res->sibling->start <= end))
505 while (tmp->sibling != res)
507 if (start <= tmp->end)
516 write_unlock(&resource_lock);
520 static void __init __reserve_region_with_split(struct resource *root,
521 resource_size_t start, resource_size_t end,
524 struct resource *parent = root;
525 struct resource *conflict;
526 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
534 res->flags = IORESOURCE_BUSY;
537 conflict = __request_resource(parent, res);
540 if (conflict != parent) {
542 if (!(conflict->flags & IORESOURCE_BUSY))
546 /* Uhhuh, that didn't work out.. */
553 /* failed, split and try again */
555 /* conflict covered whole area */
556 if (conflict->start <= start && conflict->end >= end)
559 if (conflict->start > start)
560 __reserve_region_with_split(root, start, conflict->start-1, name);
561 if (!(conflict->flags & IORESOURCE_BUSY)) {
562 resource_size_t common_start, common_end;
564 common_start = max(conflict->start, start);
565 common_end = min(conflict->end, end);
566 if (common_start < common_end)
567 __reserve_region_with_split(root, common_start, common_end, name);
569 if (conflict->end < end)
570 __reserve_region_with_split(root, conflict->end+1, end, name);
575 void __init reserve_region_with_split(struct resource *root,
576 resource_size_t start, resource_size_t end,
579 write_lock(&resource_lock);
580 __reserve_region_with_split(root, start, end, name);
581 write_unlock(&resource_lock);
584 EXPORT_SYMBOL(adjust_resource);
587 * resource_alignment - calculate resource's alignment
588 * @res: resource pointer
590 * Returns alignment on success, 0 (invalid alignment) on failure.
592 resource_size_t resource_alignment(struct resource *res)
594 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
595 case IORESOURCE_SIZEALIGN:
596 return resource_size(res);
597 case IORESOURCE_STARTALIGN:
605 * This is compatibility stuff for IO resources.
607 * Note how this, unlike the above, knows about
608 * the IO flag meanings (busy etc).
610 * request_region creates a new busy region.
612 * check_region returns non-zero if the area is already busy.
614 * release_region releases a matching busy region.
618 * __request_region - create a new busy resource region
619 * @parent: parent resource descriptor
620 * @start: resource start address
621 * @n: resource region size
622 * @name: reserving caller's ID string
624 struct resource * __request_region(struct resource *parent,
625 resource_size_t start, resource_size_t n,
626 const char *name, int flags)
628 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
635 res->end = start + n - 1;
636 res->flags = IORESOURCE_BUSY;
639 write_lock(&resource_lock);
642 struct resource *conflict;
644 conflict = __request_resource(parent, res);
647 if (conflict != parent) {
649 if (!(conflict->flags & IORESOURCE_BUSY))
653 /* Uhhuh, that didn't work out.. */
658 write_unlock(&resource_lock);
661 EXPORT_SYMBOL(__request_region);
664 * __check_region - check if a resource region is busy or free
665 * @parent: parent resource descriptor
666 * @start: resource start address
667 * @n: resource region size
669 * Returns 0 if the region is free at the moment it is checked,
670 * returns %-EBUSY if the region is busy.
673 * This function is deprecated because its use is racy.
674 * Even if it returns 0, a subsequent call to request_region()
675 * may fail because another driver etc. just allocated the region.
676 * Do NOT use it. It will be removed from the kernel.
678 int __check_region(struct resource *parent, resource_size_t start,
681 struct resource * res;
683 res = __request_region(parent, start, n, "check-region", 0);
687 release_resource(res);
691 EXPORT_SYMBOL(__check_region);
694 * __release_region - release a previously reserved resource region
695 * @parent: parent resource descriptor
696 * @start: resource start address
697 * @n: resource region size
699 * The described resource region must match a currently busy region.
701 void __release_region(struct resource *parent, resource_size_t start,
710 write_lock(&resource_lock);
713 struct resource *res = *p;
717 if (res->start <= start && res->end >= end) {
718 if (!(res->flags & IORESOURCE_BUSY)) {
722 if (res->start != start || res->end != end)
725 write_unlock(&resource_lock);
732 write_unlock(&resource_lock);
734 printk(KERN_WARNING "Trying to free nonexistent resource "
735 "<%016llx-%016llx>\n", (unsigned long long)start,
736 (unsigned long long)end);
738 EXPORT_SYMBOL(__release_region);
741 * Managed region resource
743 struct region_devres {
744 struct resource *parent;
745 resource_size_t start;
749 static void devm_region_release(struct device *dev, void *res)
751 struct region_devres *this = res;
753 __release_region(this->parent, this->start, this->n);
756 static int devm_region_match(struct device *dev, void *res, void *match_data)
758 struct region_devres *this = res, *match = match_data;
760 return this->parent == match->parent &&
761 this->start == match->start && this->n == match->n;
764 struct resource * __devm_request_region(struct device *dev,
765 struct resource *parent, resource_size_t start,
766 resource_size_t n, const char *name)
768 struct region_devres *dr = NULL;
769 struct resource *res;
771 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
780 res = __request_region(parent, start, n, name, 0);
788 EXPORT_SYMBOL(__devm_request_region);
790 void __devm_release_region(struct device *dev, struct resource *parent,
791 resource_size_t start, resource_size_t n)
793 struct region_devres match_data = { parent, start, n };
795 __release_region(parent, start, n);
796 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
799 EXPORT_SYMBOL(__devm_release_region);
802 * Called from init/main.c to reserve IO ports.
805 static int __init reserve_setup(char *str)
808 static struct resource reserve[MAXRESERVE];
811 int io_start, io_num;
814 if (get_option (&str, &io_start) != 2)
816 if (get_option (&str, &io_num) == 0)
818 if (x < MAXRESERVE) {
819 struct resource *res = reserve + x;
820 res->name = "reserved";
821 res->start = io_start;
822 res->end = io_start + io_num - 1;
823 res->flags = IORESOURCE_BUSY;
825 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
832 __setup("reserve=", reserve_setup);
835 * Check if the requested addr and size spans more than any slot in the
836 * iomem resource tree.
838 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
840 struct resource *p = &iomem_resource;
844 read_lock(&resource_lock);
845 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
847 * We can probably skip the resources without
848 * IORESOURCE_IO attribute?
850 if (p->start >= addr + size)
854 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
855 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
858 * if a resource is "BUSY", it's not a hardware resource
859 * but a driver mapping of such a resource; we don't want
860 * to warn for those; some drivers legitimately map only
861 * partial hardware resources. (example: vesafb)
863 if (p->flags & IORESOURCE_BUSY)
866 printk(KERN_WARNING "resource map sanity check conflict: "
867 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
868 (unsigned long long)addr,
869 (unsigned long long)(addr + size - 1),
870 (unsigned long long)p->start,
871 (unsigned long long)p->end,
876 read_unlock(&resource_lock);
881 #ifdef CONFIG_STRICT_DEVMEM
882 static int strict_iomem_checks = 1;
884 static int strict_iomem_checks;
888 * check if an address is reserved in the iomem resource tree
889 * returns 1 if reserved, 0 if not reserved.
891 int iomem_is_exclusive(u64 addr)
893 struct resource *p = &iomem_resource;
896 int size = PAGE_SIZE;
898 if (!strict_iomem_checks)
901 addr = addr & PAGE_MASK;
903 read_lock(&resource_lock);
904 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
906 * We can probably skip the resources without
907 * IORESOURCE_IO attribute?
909 if (p->start >= addr + size)
913 if (p->flags & IORESOURCE_BUSY &&
914 p->flags & IORESOURCE_EXCLUSIVE) {
919 read_unlock(&resource_lock);
924 static int __init strict_iomem(char *str)
926 if (strstr(str, "relaxed"))
927 strict_iomem_checks = 0;
928 if (strstr(str, "strict"))
929 strict_iomem_checks = 1;
933 __setup("iomem=", strict_iomem);