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;
191 static void __release_child_resources(struct resource *r)
193 struct resource *tmp, *p;
194 resource_size_t size;
204 __release_child_resources(tmp);
206 printk(KERN_DEBUG "release child resource %pR\n", tmp);
207 /* need to restore size, and keep flags */
208 size = resource_size(tmp);
214 void release_child_resources(struct resource *r)
216 write_lock(&resource_lock);
217 __release_child_resources(r);
218 write_unlock(&resource_lock);
222 * request_resource - request and reserve an I/O or memory resource
223 * @root: root resource descriptor
224 * @new: resource descriptor desired by caller
226 * Returns 0 for success, negative error code on error.
228 int request_resource(struct resource *root, struct resource *new)
230 struct resource *conflict;
232 write_lock(&resource_lock);
233 conflict = __request_resource(root, new);
234 write_unlock(&resource_lock);
235 return conflict ? -EBUSY : 0;
238 EXPORT_SYMBOL(request_resource);
241 * release_resource - release a previously reserved resource
242 * @old: resource pointer
244 int release_resource(struct resource *old)
248 write_lock(&resource_lock);
249 retval = __release_resource(old);
250 write_unlock(&resource_lock);
254 EXPORT_SYMBOL(release_resource);
256 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
258 * Finds the lowest memory reosurce exists within [res->start.res->end)
259 * the caller must specify res->start, res->end, res->flags and "name".
260 * If found, returns 0, res is overwritten, if not found, returns -1.
262 static int find_next_system_ram(struct resource *res, char *name)
264 resource_size_t start, end;
271 BUG_ON(start >= end);
273 read_lock(&resource_lock);
274 for (p = iomem_resource.child; p ; p = p->sibling) {
275 /* system ram is just marked as IORESOURCE_MEM */
276 if (p->flags != res->flags)
278 if (name && strcmp(p->name, name))
280 if (p->start > end) {
284 if ((p->end >= start) && (p->start < end))
287 read_unlock(&resource_lock);
291 if (res->start < p->start)
292 res->start = p->start;
293 if (res->end > p->end)
299 * This function calls callback against all memory range of "System RAM"
300 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
301 * Now, this function is only for "System RAM".
303 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
304 void *arg, int (*func)(unsigned long, unsigned long, void *))
307 unsigned long pfn, len;
311 res.start = (u64) start_pfn << PAGE_SHIFT;
312 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
313 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
315 while ((res.start < res.end) &&
316 (find_next_system_ram(&res, "System RAM") >= 0)) {
317 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
318 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
319 ret = (*func)(pfn, len, arg);
322 res.start = res.end + 1;
330 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
335 * This generic page_is_ram() returns true if specified address is
336 * registered as "System RAM" in iomem_resource list.
338 int __weak page_is_ram(unsigned long pfn)
340 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
344 * Find empty slot in the resource tree given range and alignment.
346 static int find_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 resource_size_t (*alignf)(void *,
350 const struct resource *,
355 struct resource *this = root->child;
356 struct resource tmp = *new;
358 tmp.start = root->start;
360 * Skip past an allocated resource that starts at 0, since the assignment
361 * of this->start - 1 to tmp->end below would cause an underflow.
363 if (this && this->start == 0) {
364 tmp.start = this->end + 1;
365 this = this->sibling;
369 tmp.end = this->start - 1;
376 tmp.start = ALIGN(tmp.start, align);
378 tmp.start = alignf(alignf_data, &tmp, size, align);
379 if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
380 new->start = tmp.start;
381 new->end = tmp.start + size - 1;
386 tmp.start = this->end + 1;
387 this = this->sibling;
393 * allocate_resource - allocate empty slot in the resource tree given range & alignment
394 * @root: root resource descriptor
395 * @new: resource descriptor desired by caller
396 * @size: requested resource region size
397 * @min: minimum size to allocate
398 * @max: maximum size to allocate
399 * @align: alignment requested, in bytes
400 * @alignf: alignment function, optional, called if not NULL
401 * @alignf_data: arbitrary data to pass to the @alignf function
403 int allocate_resource(struct resource *root, struct resource *new,
404 resource_size_t size, resource_size_t min,
405 resource_size_t max, resource_size_t align,
406 resource_size_t (*alignf)(void *,
407 const struct resource *,
414 write_lock(&resource_lock);
415 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
416 if (err >= 0 && __request_resource(root, new))
418 write_unlock(&resource_lock);
422 EXPORT_SYMBOL(allocate_resource);
425 * Insert a resource into the resource tree. If successful, return NULL,
426 * otherwise return the conflicting resource (compare to __request_resource())
428 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
430 struct resource *first, *next;
432 for (;; parent = first) {
433 first = __request_resource(parent, new);
440 if ((first->start > new->start) || (first->end < new->end))
442 if ((first->start == new->start) && (first->end == new->end))
446 for (next = first; ; next = next->sibling) {
447 /* Partial overlap? Bad, and unfixable */
448 if (next->start < new->start || next->end > new->end)
452 if (next->sibling->start > new->end)
456 new->parent = parent;
457 new->sibling = next->sibling;
460 next->sibling = NULL;
461 for (next = first; next; next = next->sibling)
464 if (parent->child == first) {
467 next = parent->child;
468 while (next->sibling != first)
469 next = next->sibling;
476 * insert_resource - Inserts a resource in the resource tree
477 * @parent: parent of the new resource
478 * @new: new resource to insert
480 * Returns 0 on success, -EBUSY if the resource can't be inserted.
482 * This function is equivalent to request_resource when no conflict
483 * happens. If a conflict happens, and the conflicting resources
484 * entirely fit within the range of the new resource, then the new
485 * resource is inserted and the conflicting resources become children of
488 int insert_resource(struct resource *parent, struct resource *new)
490 struct resource *conflict;
492 write_lock(&resource_lock);
493 conflict = __insert_resource(parent, new);
494 write_unlock(&resource_lock);
495 return conflict ? -EBUSY : 0;
499 * insert_resource_expand_to_fit - Insert a resource into the resource tree
500 * @root: root resource descriptor
501 * @new: new resource to insert
503 * Insert a resource into the resource tree, possibly expanding it in order
504 * to make it encompass any conflicting resources.
506 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
511 write_lock(&resource_lock);
513 struct resource *conflict;
515 conflict = __insert_resource(root, new);
518 if (conflict == root)
521 /* Ok, expand resource to cover the conflict, then try again .. */
522 if (conflict->start < new->start)
523 new->start = conflict->start;
524 if (conflict->end > new->end)
525 new->end = conflict->end;
527 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
529 write_unlock(&resource_lock);
533 * adjust_resource - modify a resource's start and size
534 * @res: resource to modify
535 * @start: new start value
538 * Given an existing resource, change its start and size to match the
539 * arguments. Returns 0 on success, -EBUSY if it can't fit.
540 * Existing children of the resource are assumed to be immutable.
542 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
544 struct resource *tmp, *parent = res->parent;
545 resource_size_t end = start + size - 1;
548 write_lock(&resource_lock);
550 if ((start < parent->start) || (end > parent->end))
553 for (tmp = res->child; tmp; tmp = tmp->sibling) {
554 if ((tmp->start < start) || (tmp->end > end))
558 if (res->sibling && (res->sibling->start <= end))
563 while (tmp->sibling != res)
565 if (start <= tmp->end)
574 write_unlock(&resource_lock);
578 static void __init __reserve_region_with_split(struct resource *root,
579 resource_size_t start, resource_size_t end,
582 struct resource *parent = root;
583 struct resource *conflict;
584 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
592 res->flags = IORESOURCE_BUSY;
594 conflict = __request_resource(parent, res);
598 /* failed, split and try again */
601 /* conflict covered whole area */
602 if (conflict->start <= start && conflict->end >= end)
605 if (conflict->start > start)
606 __reserve_region_with_split(root, start, conflict->start-1, name);
607 if (conflict->end < end)
608 __reserve_region_with_split(root, conflict->end+1, end, name);
611 void __init reserve_region_with_split(struct resource *root,
612 resource_size_t start, resource_size_t end,
615 write_lock(&resource_lock);
616 __reserve_region_with_split(root, start, end, name);
617 write_unlock(&resource_lock);
620 EXPORT_SYMBOL(adjust_resource);
623 * resource_alignment - calculate resource's alignment
624 * @res: resource pointer
626 * Returns alignment on success, 0 (invalid alignment) on failure.
628 resource_size_t resource_alignment(struct resource *res)
630 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
631 case IORESOURCE_SIZEALIGN:
632 return resource_size(res);
633 case IORESOURCE_STARTALIGN:
641 * This is compatibility stuff for IO resources.
643 * Note how this, unlike the above, knows about
644 * the IO flag meanings (busy etc).
646 * request_region creates a new busy region.
648 * check_region returns non-zero if the area is already busy.
650 * release_region releases a matching busy region.
654 * __request_region - create a new busy resource region
655 * @parent: parent resource descriptor
656 * @start: resource start address
657 * @n: resource region size
658 * @name: reserving caller's ID string
659 * @flags: IO resource flags
661 struct resource * __request_region(struct resource *parent,
662 resource_size_t start, resource_size_t n,
663 const char *name, int flags)
665 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
672 res->end = start + n - 1;
673 res->flags = IORESOURCE_BUSY;
676 write_lock(&resource_lock);
679 struct resource *conflict;
681 conflict = __request_resource(parent, res);
684 if (conflict != parent) {
686 if (!(conflict->flags & IORESOURCE_BUSY))
690 /* Uhhuh, that didn't work out.. */
695 write_unlock(&resource_lock);
698 EXPORT_SYMBOL(__request_region);
701 * __check_region - check if a resource region is busy or free
702 * @parent: parent resource descriptor
703 * @start: resource start address
704 * @n: resource region size
706 * Returns 0 if the region is free at the moment it is checked,
707 * returns %-EBUSY if the region is busy.
710 * This function is deprecated because its use is racy.
711 * Even if it returns 0, a subsequent call to request_region()
712 * may fail because another driver etc. just allocated the region.
713 * Do NOT use it. It will be removed from the kernel.
715 int __check_region(struct resource *parent, resource_size_t start,
718 struct resource * res;
720 res = __request_region(parent, start, n, "check-region", 0);
724 release_resource(res);
728 EXPORT_SYMBOL(__check_region);
731 * __release_region - release a previously reserved resource region
732 * @parent: parent resource descriptor
733 * @start: resource start address
734 * @n: resource region size
736 * The described resource region must match a currently busy region.
738 void __release_region(struct resource *parent, resource_size_t start,
747 write_lock(&resource_lock);
750 struct resource *res = *p;
754 if (res->start <= start && res->end >= end) {
755 if (!(res->flags & IORESOURCE_BUSY)) {
759 if (res->start != start || res->end != end)
762 write_unlock(&resource_lock);
769 write_unlock(&resource_lock);
771 printk(KERN_WARNING "Trying to free nonexistent resource "
772 "<%016llx-%016llx>\n", (unsigned long long)start,
773 (unsigned long long)end);
775 EXPORT_SYMBOL(__release_region);
778 * Managed region resource
780 struct region_devres {
781 struct resource *parent;
782 resource_size_t start;
786 static void devm_region_release(struct device *dev, void *res)
788 struct region_devres *this = res;
790 __release_region(this->parent, this->start, this->n);
793 static int devm_region_match(struct device *dev, void *res, void *match_data)
795 struct region_devres *this = res, *match = match_data;
797 return this->parent == match->parent &&
798 this->start == match->start && this->n == match->n;
801 struct resource * __devm_request_region(struct device *dev,
802 struct resource *parent, resource_size_t start,
803 resource_size_t n, const char *name)
805 struct region_devres *dr = NULL;
806 struct resource *res;
808 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
817 res = __request_region(parent, start, n, name, 0);
825 EXPORT_SYMBOL(__devm_request_region);
827 void __devm_release_region(struct device *dev, struct resource *parent,
828 resource_size_t start, resource_size_t n)
830 struct region_devres match_data = { parent, start, n };
832 __release_region(parent, start, n);
833 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
836 EXPORT_SYMBOL(__devm_release_region);
839 * Called from init/main.c to reserve IO ports.
842 static int __init reserve_setup(char *str)
845 static struct resource reserve[MAXRESERVE];
848 unsigned int io_start, io_num;
851 if (get_option (&str, &io_start) != 2)
853 if (get_option (&str, &io_num) == 0)
855 if (x < MAXRESERVE) {
856 struct resource *res = reserve + x;
857 res->name = "reserved";
858 res->start = io_start;
859 res->end = io_start + io_num - 1;
860 res->flags = IORESOURCE_BUSY;
862 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
869 __setup("reserve=", reserve_setup);
872 * Check if the requested addr and size spans more than any slot in the
873 * iomem resource tree.
875 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
877 struct resource *p = &iomem_resource;
881 read_lock(&resource_lock);
882 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
884 * We can probably skip the resources without
885 * IORESOURCE_IO attribute?
887 if (p->start >= addr + size)
891 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
892 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
895 * if a resource is "BUSY", it's not a hardware resource
896 * but a driver mapping of such a resource; we don't want
897 * to warn for those; some drivers legitimately map only
898 * partial hardware resources. (example: vesafb)
900 if (p->flags & IORESOURCE_BUSY)
903 printk(KERN_WARNING "resource map sanity check conflict: "
904 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
905 (unsigned long long)addr,
906 (unsigned long long)(addr + size - 1),
907 (unsigned long long)p->start,
908 (unsigned long long)p->end,
913 read_unlock(&resource_lock);
918 #ifdef CONFIG_STRICT_DEVMEM
919 static int strict_iomem_checks = 1;
921 static int strict_iomem_checks;
925 * check if an address is reserved in the iomem resource tree
926 * returns 1 if reserved, 0 if not reserved.
928 int iomem_is_exclusive(u64 addr)
930 struct resource *p = &iomem_resource;
933 int size = PAGE_SIZE;
935 if (!strict_iomem_checks)
938 addr = addr & PAGE_MASK;
940 read_lock(&resource_lock);
941 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
943 * We can probably skip the resources without
944 * IORESOURCE_IO attribute?
946 if (p->start >= addr + size)
950 if (p->flags & IORESOURCE_BUSY &&
951 p->flags & IORESOURCE_EXCLUSIVE) {
956 read_unlock(&resource_lock);
961 static int __init strict_iomem(char *str)
963 if (strstr(str, "relaxed"))
964 strict_iomem_checks = 0;
965 if (strstr(str, "strict"))
966 strict_iomem_checks = 1;
970 __setup("iomem=", strict_iomem);