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_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 and "name".
230 * If found, returns 0, res is overwritten, if not found, returns -1.
232 static int find_next_system_ram(struct resource *res, char *name)
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 (name && strcmp(p->name, name))
250 if (p->start > end) {
254 if ((p->end >= start) && (p->start < end))
257 read_unlock(&resource_lock);
261 if (res->start < p->start)
262 res->start = p->start;
263 if (res->end > p->end)
269 * This function calls callback against all memory range of "System RAM"
270 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
271 * Now, this function is only for "System RAM".
273 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
274 void *arg, int (*func)(unsigned long, unsigned long, void *))
277 unsigned long pfn, end_pfn;
281 res.start = (u64) start_pfn << PAGE_SHIFT;
282 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
283 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
285 while ((res.start < res.end) &&
286 (find_next_system_ram(&res, "System RAM") >= 0)) {
287 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
288 end_pfn = (res.end + 1) >> PAGE_SHIFT;
290 ret = (*func)(pfn, end_pfn - pfn, arg);
293 res.start = res.end + 1;
301 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
306 * This generic page_is_ram() returns true if specified address is
307 * registered as "System RAM" in iomem_resource list.
309 int __weak page_is_ram(unsigned long pfn)
311 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
315 * Find empty slot in the resource tree given range and alignment.
317 static int find_resource(struct resource *root, struct resource *new,
318 resource_size_t size, resource_size_t min,
319 resource_size_t max, resource_size_t align,
320 void (*alignf)(void *, struct resource *,
321 resource_size_t, resource_size_t),
324 struct resource *this = root->child;
325 struct resource tmp = *new;
327 tmp.start = root->start;
329 * Skip past an allocated resource that starts at 0, since the assignment
330 * of this->start - 1 to tmp->end below would cause an underflow.
332 if (this && this->start == 0) {
333 tmp.start = this->end + 1;
334 this = this->sibling;
338 tmp.end = this->start - 1;
345 tmp.start = ALIGN(tmp.start, align);
347 alignf(alignf_data, &tmp, size, align);
348 if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
349 new->start = tmp.start;
350 new->end = tmp.start + size - 1;
355 tmp.start = this->end + 1;
356 this = this->sibling;
362 * allocate_resource - allocate empty slot in the resource tree given range & alignment
363 * @root: root resource descriptor
364 * @new: resource descriptor desired by caller
365 * @size: requested resource region size
366 * @min: minimum size to allocate
367 * @max: maximum size to allocate
368 * @align: alignment requested, in bytes
369 * @alignf: alignment function, optional, called if not NULL
370 * @alignf_data: arbitrary data to pass to the @alignf function
372 int allocate_resource(struct resource *root, struct resource *new,
373 resource_size_t size, resource_size_t min,
374 resource_size_t max, resource_size_t align,
375 void (*alignf)(void *, struct resource *,
376 resource_size_t, resource_size_t),
381 write_lock(&resource_lock);
382 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
383 if (err >= 0 && __request_resource(root, new))
385 write_unlock(&resource_lock);
389 EXPORT_SYMBOL(allocate_resource);
392 * Insert a resource into the resource tree. If successful, return NULL,
393 * otherwise return the conflicting resource (compare to __request_resource())
395 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
397 struct resource *first, *next;
399 for (;; parent = first) {
400 first = __request_resource(parent, new);
407 if ((first->start > new->start) || (first->end < new->end))
409 if ((first->start == new->start) && (first->end == new->end))
413 for (next = first; ; next = next->sibling) {
414 /* Partial overlap? Bad, and unfixable */
415 if (next->start < new->start || next->end > new->end)
419 if (next->sibling->start > new->end)
423 new->parent = parent;
424 new->sibling = next->sibling;
427 next->sibling = NULL;
428 for (next = first; next; next = next->sibling)
431 if (parent->child == first) {
434 next = parent->child;
435 while (next->sibling != first)
436 next = next->sibling;
443 * insert_resource - Inserts a resource in the resource tree
444 * @parent: parent of the new resource
445 * @new: new resource to insert
447 * Returns 0 on success, -EBUSY if the resource can't be inserted.
449 * This function is equivalent to request_resource when no conflict
450 * happens. If a conflict happens, and the conflicting resources
451 * entirely fit within the range of the new resource, then the new
452 * resource is inserted and the conflicting resources become children of
455 int insert_resource(struct resource *parent, struct resource *new)
457 struct resource *conflict;
459 write_lock(&resource_lock);
460 conflict = __insert_resource(parent, new);
461 write_unlock(&resource_lock);
462 return conflict ? -EBUSY : 0;
466 * insert_resource_expand_to_fit - Insert a resource into the resource tree
467 * @root: root resource descriptor
468 * @new: new resource to insert
470 * Insert a resource into the resource tree, possibly expanding it in order
471 * to make it encompass any conflicting resources.
473 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
478 write_lock(&resource_lock);
480 struct resource *conflict;
482 conflict = __insert_resource(root, new);
485 if (conflict == root)
488 /* Ok, expand resource to cover the conflict, then try again .. */
489 if (conflict->start < new->start)
490 new->start = conflict->start;
491 if (conflict->end > new->end)
492 new->end = conflict->end;
494 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
496 write_unlock(&resource_lock);
500 * adjust_resource - modify a resource's start and size
501 * @res: resource to modify
502 * @start: new start value
505 * Given an existing resource, change its start and size to match the
506 * arguments. Returns 0 on success, -EBUSY if it can't fit.
507 * Existing children of the resource are assumed to be immutable.
509 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
511 struct resource *tmp, *parent = res->parent;
512 resource_size_t end = start + size - 1;
515 write_lock(&resource_lock);
517 if ((start < parent->start) || (end > parent->end))
520 for (tmp = res->child; tmp; tmp = tmp->sibling) {
521 if ((tmp->start < start) || (tmp->end > end))
525 if (res->sibling && (res->sibling->start <= end))
530 while (tmp->sibling != res)
532 if (start <= tmp->end)
541 write_unlock(&resource_lock);
545 static void __init __reserve_region_with_split(struct resource *root,
546 resource_size_t start, resource_size_t end,
549 struct resource *parent = root;
550 struct resource *conflict;
551 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
559 res->flags = IORESOURCE_BUSY;
561 conflict = __request_resource(parent, res);
565 /* failed, split and try again */
568 /* conflict covered whole area */
569 if (conflict->start <= start && conflict->end >= end)
572 if (conflict->start > start)
573 __reserve_region_with_split(root, start, conflict->start-1, name);
574 if (conflict->end < end)
575 __reserve_region_with_split(root, conflict->end+1, end, name);
578 void __init reserve_region_with_split(struct resource *root,
579 resource_size_t start, resource_size_t end,
582 write_lock(&resource_lock);
583 __reserve_region_with_split(root, start, end, name);
584 write_unlock(&resource_lock);
587 EXPORT_SYMBOL(adjust_resource);
590 * resource_alignment - calculate resource's alignment
591 * @res: resource pointer
593 * Returns alignment on success, 0 (invalid alignment) on failure.
595 resource_size_t resource_alignment(struct resource *res)
597 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
598 case IORESOURCE_SIZEALIGN:
599 return resource_size(res);
600 case IORESOURCE_STARTALIGN:
608 * This is compatibility stuff for IO resources.
610 * Note how this, unlike the above, knows about
611 * the IO flag meanings (busy etc).
613 * request_region creates a new busy region.
615 * check_region returns non-zero if the area is already busy.
617 * release_region releases a matching busy region.
621 * __request_region - create a new busy resource region
622 * @parent: parent resource descriptor
623 * @start: resource start address
624 * @n: resource region size
625 * @name: reserving caller's ID string
626 * @flags: IO resource flags
628 struct resource * __request_region(struct resource *parent,
629 resource_size_t start, resource_size_t n,
630 const char *name, int flags)
632 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
639 res->end = start + n - 1;
640 res->flags = IORESOURCE_BUSY;
643 write_lock(&resource_lock);
646 struct resource *conflict;
648 conflict = __request_resource(parent, res);
651 if (conflict != parent) {
653 if (!(conflict->flags & IORESOURCE_BUSY))
657 /* Uhhuh, that didn't work out.. */
662 write_unlock(&resource_lock);
665 EXPORT_SYMBOL(__request_region);
668 * __check_region - check if a resource region is busy or free
669 * @parent: parent resource descriptor
670 * @start: resource start address
671 * @n: resource region size
673 * Returns 0 if the region is free at the moment it is checked,
674 * returns %-EBUSY if the region is busy.
677 * This function is deprecated because its use is racy.
678 * Even if it returns 0, a subsequent call to request_region()
679 * may fail because another driver etc. just allocated the region.
680 * Do NOT use it. It will be removed from the kernel.
682 int __check_region(struct resource *parent, resource_size_t start,
685 struct resource * res;
687 res = __request_region(parent, start, n, "check-region", 0);
691 release_resource(res);
695 EXPORT_SYMBOL(__check_region);
698 * __release_region - release a previously reserved resource region
699 * @parent: parent resource descriptor
700 * @start: resource start address
701 * @n: resource region size
703 * The described resource region must match a currently busy region.
705 void __release_region(struct resource *parent, resource_size_t start,
714 write_lock(&resource_lock);
717 struct resource *res = *p;
721 if (res->start <= start && res->end >= end) {
722 if (!(res->flags & IORESOURCE_BUSY)) {
726 if (res->start != start || res->end != end)
729 write_unlock(&resource_lock);
736 write_unlock(&resource_lock);
738 printk(KERN_WARNING "Trying to free nonexistent resource "
739 "<%016llx-%016llx>\n", (unsigned long long)start,
740 (unsigned long long)end);
742 EXPORT_SYMBOL(__release_region);
745 * Managed region resource
747 struct region_devres {
748 struct resource *parent;
749 resource_size_t start;
753 static void devm_region_release(struct device *dev, void *res)
755 struct region_devres *this = res;
757 __release_region(this->parent, this->start, this->n);
760 static int devm_region_match(struct device *dev, void *res, void *match_data)
762 struct region_devres *this = res, *match = match_data;
764 return this->parent == match->parent &&
765 this->start == match->start && this->n == match->n;
768 struct resource * __devm_request_region(struct device *dev,
769 struct resource *parent, resource_size_t start,
770 resource_size_t n, const char *name)
772 struct region_devres *dr = NULL;
773 struct resource *res;
775 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
784 res = __request_region(parent, start, n, name, 0);
792 EXPORT_SYMBOL(__devm_request_region);
794 void __devm_release_region(struct device *dev, struct resource *parent,
795 resource_size_t start, resource_size_t n)
797 struct region_devres match_data = { parent, start, n };
799 __release_region(parent, start, n);
800 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
803 EXPORT_SYMBOL(__devm_release_region);
806 * Called from init/main.c to reserve IO ports.
809 static int __init reserve_setup(char *str)
812 static struct resource reserve[MAXRESERVE];
815 unsigned int io_start, io_num;
818 if (get_option (&str, &io_start) != 2)
820 if (get_option (&str, &io_num) == 0)
822 if (x < MAXRESERVE) {
823 struct resource *res = reserve + x;
824 res->name = "reserved";
825 res->start = io_start;
826 res->end = io_start + io_num - 1;
827 res->flags = IORESOURCE_BUSY;
829 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
836 __setup("reserve=", reserve_setup);
839 * Check if the requested addr and size spans more than any slot in the
840 * iomem resource tree.
842 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
844 struct resource *p = &iomem_resource;
848 read_lock(&resource_lock);
849 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
851 * We can probably skip the resources without
852 * IORESOURCE_IO attribute?
854 if (p->start >= addr + size)
858 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
859 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
862 * if a resource is "BUSY", it's not a hardware resource
863 * but a driver mapping of such a resource; we don't want
864 * to warn for those; some drivers legitimately map only
865 * partial hardware resources. (example: vesafb)
867 if (p->flags & IORESOURCE_BUSY)
870 printk(KERN_WARNING "resource map sanity check conflict: "
871 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
872 (unsigned long long)addr,
873 (unsigned long long)(addr + size - 1),
874 (unsigned long long)p->start,
875 (unsigned long long)p->end,
880 read_unlock(&resource_lock);
885 #ifdef CONFIG_STRICT_DEVMEM
886 static int strict_iomem_checks = 1;
888 static int strict_iomem_checks;
892 * check if an address is reserved in the iomem resource tree
893 * returns 1 if reserved, 0 if not reserved.
895 int iomem_is_exclusive(u64 addr)
897 struct resource *p = &iomem_resource;
900 int size = PAGE_SIZE;
902 if (!strict_iomem_checks)
905 addr = addr & PAGE_MASK;
907 read_lock(&resource_lock);
908 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
910 * We can probably skip the resources without
911 * IORESOURCE_IO attribute?
913 if (p->start >= addr + size)
917 if (p->flags & IORESOURCE_BUSY &&
918 p->flags & IORESOURCE_EXCLUSIVE) {
923 read_unlock(&resource_lock);
928 static int __init strict_iomem(char *str)
930 if (strstr(str, "relaxed"))
931 strict_iomem_checks = 0;
932 if (strstr(str, "strict"))
933 strict_iomem_checks = 1;
937 __setup("iomem=", strict_iomem);