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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/export.h>
13 #include <linux/errno.h>
14 #include <linux/ioport.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
19 #include <linux/proc_fs.h>
20 #include <linux/sched.h>
21 #include <linux/seq_file.h>
22 #include <linux/device.h>
23 #include <linux/pfn.h>
28 struct resource ioport_resource = {
31 .end = IO_SPACE_LIMIT,
32 .flags = IORESOURCE_IO,
34 EXPORT_SYMBOL(ioport_resource);
36 struct resource iomem_resource = {
40 .flags = IORESOURCE_MEM,
42 EXPORT_SYMBOL(iomem_resource);
44 /* constraints to be met while allocating resources */
45 struct resource_constraint {
46 resource_size_t min, max, align;
47 resource_size_t (*alignf)(void *, const struct resource *,
48 resource_size_t, resource_size_t);
52 static DEFINE_RWLOCK(resource_lock);
55 * For memory hotplug, there is no way to free resource entries allocated
56 * by boot mem after the system is up. So for reusing the resource entry
57 * we need to remember the resource.
59 static struct resource *bootmem_resource_free;
60 static DEFINE_SPINLOCK(bootmem_resource_lock);
62 static struct resource *next_resource(struct resource *p, bool sibling_only)
64 /* Caller wants to traverse through siblings only */
70 while (!p->sibling && p->parent)
75 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
77 struct resource *p = v;
79 return (void *)next_resource(p, false);
84 enum { MAX_IORES_LEVEL = 5 };
86 static void *r_start(struct seq_file *m, loff_t *pos)
87 __acquires(resource_lock)
89 struct resource *p = m->private;
91 read_lock(&resource_lock);
92 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
97 static void r_stop(struct seq_file *m, void *v)
98 __releases(resource_lock)
100 read_unlock(&resource_lock);
103 static int r_show(struct seq_file *m, void *v)
105 struct resource *root = m->private;
106 struct resource *r = v, *p;
107 int width = root->end < 0x10000 ? 4 : 8;
110 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
111 if (p->parent == root)
113 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
115 width, (unsigned long long) r->start,
116 width, (unsigned long long) r->end,
117 r->name ? r->name : "<BAD>");
121 static const struct seq_operations resource_op = {
128 static int ioports_open(struct inode *inode, struct file *file)
130 int res = seq_open(file, &resource_op);
132 struct seq_file *m = file->private_data;
133 m->private = &ioport_resource;
138 static int iomem_open(struct inode *inode, struct file *file)
140 int res = seq_open(file, &resource_op);
142 struct seq_file *m = file->private_data;
143 m->private = &iomem_resource;
148 static const struct file_operations proc_ioports_operations = {
149 .open = ioports_open,
152 .release = seq_release,
155 static const struct file_operations proc_iomem_operations = {
159 .release = seq_release,
162 static int __init ioresources_init(void)
164 proc_create("ioports", 0, NULL, &proc_ioports_operations);
165 proc_create("iomem", 0, NULL, &proc_iomem_operations);
168 __initcall(ioresources_init);
170 #endif /* CONFIG_PROC_FS */
172 static void free_resource(struct resource *res)
177 if (!PageSlab(virt_to_head_page(res))) {
178 spin_lock(&bootmem_resource_lock);
179 res->sibling = bootmem_resource_free;
180 bootmem_resource_free = res;
181 spin_unlock(&bootmem_resource_lock);
187 static struct resource *alloc_resource(gfp_t flags)
189 struct resource *res = NULL;
191 spin_lock(&bootmem_resource_lock);
192 if (bootmem_resource_free) {
193 res = bootmem_resource_free;
194 bootmem_resource_free = res->sibling;
196 spin_unlock(&bootmem_resource_lock);
199 memset(res, 0, sizeof(struct resource));
201 res = kzalloc(sizeof(struct resource), flags);
206 /* Return the conflict entry if you can't request it */
207 static struct resource * __request_resource(struct resource *root, struct resource *new)
209 resource_size_t start = new->start;
210 resource_size_t end = new->end;
211 struct resource *tmp, **p;
215 if (start < root->start)
222 if (!tmp || tmp->start > end) {
229 if (tmp->end < start)
235 static int __release_resource(struct resource *old)
237 struct resource *tmp, **p;
239 p = &old->parent->child;
254 static void __release_child_resources(struct resource *r)
256 struct resource *tmp, *p;
257 resource_size_t size;
267 __release_child_resources(tmp);
269 printk(KERN_DEBUG "release child resource %pR\n", tmp);
270 /* need to restore size, and keep flags */
271 size = resource_size(tmp);
277 void release_child_resources(struct resource *r)
279 write_lock(&resource_lock);
280 __release_child_resources(r);
281 write_unlock(&resource_lock);
285 * request_resource_conflict - request and reserve an I/O or memory resource
286 * @root: root resource descriptor
287 * @new: resource descriptor desired by caller
289 * Returns 0 for success, conflict resource on error.
291 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
293 struct resource *conflict;
295 write_lock(&resource_lock);
296 conflict = __request_resource(root, new);
297 write_unlock(&resource_lock);
302 * request_resource - request and reserve an I/O or memory resource
303 * @root: root resource descriptor
304 * @new: resource descriptor desired by caller
306 * Returns 0 for success, negative error code on error.
308 int request_resource(struct resource *root, struct resource *new)
310 struct resource *conflict;
312 conflict = request_resource_conflict(root, new);
313 return conflict ? -EBUSY : 0;
316 EXPORT_SYMBOL(request_resource);
319 * release_resource - release a previously reserved resource
320 * @old: resource pointer
322 int release_resource(struct resource *old)
326 write_lock(&resource_lock);
327 retval = __release_resource(old);
328 write_unlock(&resource_lock);
332 EXPORT_SYMBOL(release_resource);
335 * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
336 * the caller must specify res->start, res->end, res->flags and "name".
337 * If found, returns 0, res is overwritten, if not found, returns -1.
338 * This walks through whole tree and not just first level children
339 * until and unless first_level_children_only is true.
341 static int find_next_iomem_res(struct resource *res, char *name,
342 bool first_level_children_only)
344 resource_size_t start, end;
346 bool sibling_only = false;
352 BUG_ON(start >= end);
354 read_lock(&resource_lock);
356 if (first_level_children_only) {
357 p = iomem_resource.child;
362 while ((p = next_resource(p, sibling_only))) {
363 if (p->flags != res->flags)
365 if (name && strcmp(p->name, name))
367 if (p->start > end) {
371 if ((p->end >= start) && (p->start < end))
375 read_unlock(&resource_lock);
379 if (res->start < p->start)
380 res->start = p->start;
381 if (res->end > p->end)
387 * Walks through iomem resources and calls func() with matching resource
388 * ranges. This walks through whole tree and not just first level children.
389 * All the memory ranges which overlap start,end and also match flags and
390 * name are valid candidates.
392 * @name: name of resource
393 * @flags: resource flags
397 int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
398 void *arg, int (*func)(u64, u64, void *))
408 while ((res.start < res.end) &&
409 (!find_next_iomem_res(&res, name, false))) {
410 ret = (*func)(res.start, res.end, arg);
413 res.start = res.end + 1;
420 * This function calls callback against all memory range of "System RAM"
421 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
422 * Now, this function is only for "System RAM". This function deals with
423 * full ranges and not pfn. If resources are not pfn aligned, dealing
424 * with pfn can truncate ranges.
426 int walk_system_ram_res(u64 start, u64 end, void *arg,
427 int (*func)(u64, u64, void *))
435 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
437 while ((res.start < res.end) &&
438 (!find_next_iomem_res(&res, "System RAM", true))) {
439 ret = (*func)(res.start, res.end, arg);
442 res.start = res.end + 1;
448 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
451 * This function calls callback against all memory range of "System RAM"
452 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
453 * Now, this function is only for "System RAM".
455 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
456 void *arg, int (*func)(unsigned long, unsigned long, void *))
459 unsigned long pfn, end_pfn;
463 res.start = (u64) start_pfn << PAGE_SHIFT;
464 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
465 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
467 while ((res.start < res.end) &&
468 (find_next_iomem_res(&res, "System RAM", true) >= 0)) {
469 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
470 end_pfn = (res.end + 1) >> PAGE_SHIFT;
472 ret = (*func)(pfn, end_pfn - pfn, arg);
475 res.start = res.end + 1;
483 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
488 * This generic page_is_ram() returns true if specified address is
489 * registered as "System RAM" in iomem_resource list.
491 int __weak page_is_ram(unsigned long pfn)
493 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
495 EXPORT_SYMBOL_GPL(page_is_ram);
497 void __weak arch_remove_reservations(struct resource *avail)
501 static resource_size_t simple_align_resource(void *data,
502 const struct resource *avail,
503 resource_size_t size,
504 resource_size_t align)
509 static void resource_clip(struct resource *res, resource_size_t min,
512 if (res->start < min)
519 * Find empty slot in the resource tree with the given range and
520 * alignment constraints
522 static int __find_resource(struct resource *root, struct resource *old,
523 struct resource *new,
524 resource_size_t size,
525 struct resource_constraint *constraint)
527 struct resource *this = root->child;
528 struct resource tmp = *new, avail, alloc;
530 tmp.start = root->start;
532 * Skip past an allocated resource that starts at 0, since the assignment
533 * of this->start - 1 to tmp->end below would cause an underflow.
535 if (this && this->start == root->start) {
536 tmp.start = (this == old) ? old->start : this->end + 1;
537 this = this->sibling;
541 tmp.end = (this == old) ? this->end : this->start - 1;
545 if (tmp.end < tmp.start)
548 resource_clip(&tmp, constraint->min, constraint->max);
549 arch_remove_reservations(&tmp);
551 /* Check for overflow after ALIGN() */
552 avail.start = ALIGN(tmp.start, constraint->align);
554 avail.flags = new->flags & ~IORESOURCE_UNSET;
555 if (avail.start >= tmp.start) {
556 alloc.flags = avail.flags;
557 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
558 size, constraint->align);
559 alloc.end = alloc.start + size - 1;
560 if (resource_contains(&avail, &alloc)) {
561 new->start = alloc.start;
562 new->end = alloc.end;
567 next: if (!this || this->end == root->end)
571 tmp.start = this->end + 1;
572 this = this->sibling;
578 * Find empty slot in the resource tree given range and alignment.
580 static int find_resource(struct resource *root, struct resource *new,
581 resource_size_t size,
582 struct resource_constraint *constraint)
584 return __find_resource(root, NULL, new, size, constraint);
588 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
589 * The resource will be relocated if the new size cannot be reallocated in the
592 * @root: root resource descriptor
593 * @old: resource descriptor desired by caller
594 * @newsize: new size of the resource descriptor
595 * @constraint: the size and alignment constraints to be met.
597 static int reallocate_resource(struct resource *root, struct resource *old,
598 resource_size_t newsize,
599 struct resource_constraint *constraint)
602 struct resource new = *old;
603 struct resource *conflict;
605 write_lock(&resource_lock);
607 if ((err = __find_resource(root, old, &new, newsize, constraint)))
610 if (resource_contains(&new, old)) {
611 old->start = new.start;
621 if (resource_contains(old, &new)) {
622 old->start = new.start;
625 __release_resource(old);
627 conflict = __request_resource(root, old);
631 write_unlock(&resource_lock);
637 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
638 * The resource will be reallocated with a new size if it was already allocated
639 * @root: root resource descriptor
640 * @new: resource descriptor desired by caller
641 * @size: requested resource region size
642 * @min: minimum boundary to allocate
643 * @max: maximum boundary to allocate
644 * @align: alignment requested, in bytes
645 * @alignf: alignment function, optional, called if not NULL
646 * @alignf_data: arbitrary data to pass to the @alignf function
648 int allocate_resource(struct resource *root, struct resource *new,
649 resource_size_t size, resource_size_t min,
650 resource_size_t max, resource_size_t align,
651 resource_size_t (*alignf)(void *,
652 const struct resource *,
658 struct resource_constraint constraint;
661 alignf = simple_align_resource;
663 constraint.min = min;
664 constraint.max = max;
665 constraint.align = align;
666 constraint.alignf = alignf;
667 constraint.alignf_data = alignf_data;
670 /* resource is already allocated, try reallocating with
671 the new constraints */
672 return reallocate_resource(root, new, size, &constraint);
675 write_lock(&resource_lock);
676 err = find_resource(root, new, size, &constraint);
677 if (err >= 0 && __request_resource(root, new))
679 write_unlock(&resource_lock);
683 EXPORT_SYMBOL(allocate_resource);
686 * lookup_resource - find an existing resource by a resource start address
687 * @root: root resource descriptor
688 * @start: resource start address
690 * Returns a pointer to the resource if found, NULL otherwise
692 struct resource *lookup_resource(struct resource *root, resource_size_t start)
694 struct resource *res;
696 read_lock(&resource_lock);
697 for (res = root->child; res; res = res->sibling) {
698 if (res->start == start)
701 read_unlock(&resource_lock);
707 * Insert a resource into the resource tree. If successful, return NULL,
708 * otherwise return the conflicting resource (compare to __request_resource())
710 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
712 struct resource *first, *next;
714 for (;; parent = first) {
715 first = __request_resource(parent, new);
721 if (WARN_ON(first == new)) /* duplicated insertion */
724 if ((first->start > new->start) || (first->end < new->end))
726 if ((first->start == new->start) && (first->end == new->end))
730 for (next = first; ; next = next->sibling) {
731 /* Partial overlap? Bad, and unfixable */
732 if (next->start < new->start || next->end > new->end)
736 if (next->sibling->start > new->end)
740 new->parent = parent;
741 new->sibling = next->sibling;
744 next->sibling = NULL;
745 for (next = first; next; next = next->sibling)
748 if (parent->child == first) {
751 next = parent->child;
752 while (next->sibling != first)
753 next = next->sibling;
760 * insert_resource_conflict - Inserts resource in the resource tree
761 * @parent: parent of the new resource
762 * @new: new resource to insert
764 * Returns 0 on success, conflict resource if the resource can't be inserted.
766 * This function is equivalent to request_resource_conflict when no conflict
767 * happens. If a conflict happens, and the conflicting resources
768 * entirely fit within the range of the new resource, then the new
769 * resource is inserted and the conflicting resources become children of
772 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
774 struct resource *conflict;
776 write_lock(&resource_lock);
777 conflict = __insert_resource(parent, new);
778 write_unlock(&resource_lock);
783 * insert_resource - Inserts a resource in the resource tree
784 * @parent: parent of the new resource
785 * @new: new resource to insert
787 * Returns 0 on success, -EBUSY if the resource can't be inserted.
789 int insert_resource(struct resource *parent, struct resource *new)
791 struct resource *conflict;
793 conflict = insert_resource_conflict(parent, new);
794 return conflict ? -EBUSY : 0;
798 * insert_resource_expand_to_fit - Insert a resource into the resource tree
799 * @root: root resource descriptor
800 * @new: new resource to insert
802 * Insert a resource into the resource tree, possibly expanding it in order
803 * to make it encompass any conflicting resources.
805 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
810 write_lock(&resource_lock);
812 struct resource *conflict;
814 conflict = __insert_resource(root, new);
817 if (conflict == root)
820 /* Ok, expand resource to cover the conflict, then try again .. */
821 if (conflict->start < new->start)
822 new->start = conflict->start;
823 if (conflict->end > new->end)
824 new->end = conflict->end;
826 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
828 write_unlock(&resource_lock);
831 static int __adjust_resource(struct resource *res, resource_size_t start,
832 resource_size_t size)
834 struct resource *tmp, *parent = res->parent;
835 resource_size_t end = start + size - 1;
841 if ((start < parent->start) || (end > parent->end))
844 if (res->sibling && (res->sibling->start <= end))
849 while (tmp->sibling != res)
851 if (start <= tmp->end)
856 for (tmp = res->child; tmp; tmp = tmp->sibling)
857 if ((tmp->start < start) || (tmp->end > end))
869 * adjust_resource - modify a resource's start and size
870 * @res: resource to modify
871 * @start: new start value
874 * Given an existing resource, change its start and size to match the
875 * arguments. Returns 0 on success, -EBUSY if it can't fit.
876 * Existing children of the resource are assumed to be immutable.
878 int adjust_resource(struct resource *res, resource_size_t start,
879 resource_size_t size)
883 write_lock(&resource_lock);
884 result = __adjust_resource(res, start, size);
885 write_unlock(&resource_lock);
888 EXPORT_SYMBOL(adjust_resource);
890 static void __init __reserve_region_with_split(struct resource *root,
891 resource_size_t start, resource_size_t end,
894 struct resource *parent = root;
895 struct resource *conflict;
896 struct resource *res = alloc_resource(GFP_ATOMIC);
897 struct resource *next_res = NULL;
905 res->flags = IORESOURCE_BUSY;
909 conflict = __request_resource(parent, res);
918 /* conflict covered whole area */
919 if (conflict->start <= res->start &&
920 conflict->end >= res->end) {
926 /* failed, split and try again */
927 if (conflict->start > res->start) {
929 res->end = conflict->start - 1;
930 if (conflict->end < end) {
931 next_res = alloc_resource(GFP_ATOMIC);
936 next_res->name = name;
937 next_res->start = conflict->end + 1;
939 next_res->flags = IORESOURCE_BUSY;
942 res->start = conflict->end + 1;
948 void __init reserve_region_with_split(struct resource *root,
949 resource_size_t start, resource_size_t end,
954 write_lock(&resource_lock);
955 if (root->start > start || root->end < end) {
956 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
957 (unsigned long long)start, (unsigned long long)end,
959 if (start > root->end || end < root->start)
964 if (start < root->start)
966 pr_err("fixing request to [0x%llx-0x%llx]\n",
967 (unsigned long long)start,
968 (unsigned long long)end);
973 __reserve_region_with_split(root, start, end, name);
974 write_unlock(&resource_lock);
978 * resource_alignment - calculate resource's alignment
979 * @res: resource pointer
981 * Returns alignment on success, 0 (invalid alignment) on failure.
983 resource_size_t resource_alignment(struct resource *res)
985 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
986 case IORESOURCE_SIZEALIGN:
987 return resource_size(res);
988 case IORESOURCE_STARTALIGN:
996 * This is compatibility stuff for IO resources.
998 * Note how this, unlike the above, knows about
999 * the IO flag meanings (busy etc).
1001 * request_region creates a new busy region.
1003 * check_region returns non-zero if the area is already busy.
1005 * release_region releases a matching busy region.
1008 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1011 * __request_region - create a new busy resource region
1012 * @parent: parent resource descriptor
1013 * @start: resource start address
1014 * @n: resource region size
1015 * @name: reserving caller's ID string
1016 * @flags: IO resource flags
1018 struct resource * __request_region(struct resource *parent,
1019 resource_size_t start, resource_size_t n,
1020 const char *name, int flags)
1022 DECLARE_WAITQUEUE(wait, current);
1023 struct resource *res = alloc_resource(GFP_KERNEL);
1030 res->end = start + n - 1;
1031 res->flags = resource_type(parent);
1032 res->flags |= IORESOURCE_BUSY | flags;
1034 write_lock(&resource_lock);
1037 struct resource *conflict;
1039 conflict = __request_resource(parent, res);
1042 if (conflict != parent) {
1044 if (!(conflict->flags & IORESOURCE_BUSY))
1047 if (conflict->flags & flags & IORESOURCE_MUXED) {
1048 add_wait_queue(&muxed_resource_wait, &wait);
1049 write_unlock(&resource_lock);
1050 set_current_state(TASK_UNINTERRUPTIBLE);
1052 remove_wait_queue(&muxed_resource_wait, &wait);
1053 write_lock(&resource_lock);
1056 /* Uhhuh, that didn't work out.. */
1061 write_unlock(&resource_lock);
1064 EXPORT_SYMBOL(__request_region);
1067 * __check_region - check if a resource region is busy or free
1068 * @parent: parent resource descriptor
1069 * @start: resource start address
1070 * @n: resource region size
1072 * Returns 0 if the region is free at the moment it is checked,
1073 * returns %-EBUSY if the region is busy.
1076 * This function is deprecated because its use is racy.
1077 * Even if it returns 0, a subsequent call to request_region()
1078 * may fail because another driver etc. just allocated the region.
1079 * Do NOT use it. It will be removed from the kernel.
1081 int __check_region(struct resource *parent, resource_size_t start,
1084 struct resource * res;
1086 res = __request_region(parent, start, n, "check-region", 0);
1090 release_resource(res);
1094 EXPORT_SYMBOL(__check_region);
1097 * __release_region - release a previously reserved resource region
1098 * @parent: parent resource descriptor
1099 * @start: resource start address
1100 * @n: resource region size
1102 * The described resource region must match a currently busy region.
1104 void __release_region(struct resource *parent, resource_size_t start,
1107 struct resource **p;
1108 resource_size_t end;
1111 end = start + n - 1;
1113 write_lock(&resource_lock);
1116 struct resource *res = *p;
1120 if (res->start <= start && res->end >= end) {
1121 if (!(res->flags & IORESOURCE_BUSY)) {
1125 if (res->start != start || res->end != end)
1128 write_unlock(&resource_lock);
1129 if (res->flags & IORESOURCE_MUXED)
1130 wake_up(&muxed_resource_wait);
1137 write_unlock(&resource_lock);
1139 printk(KERN_WARNING "Trying to free nonexistent resource "
1140 "<%016llx-%016llx>\n", (unsigned long long)start,
1141 (unsigned long long)end);
1143 EXPORT_SYMBOL(__release_region);
1145 #ifdef CONFIG_MEMORY_HOTREMOVE
1147 * release_mem_region_adjustable - release a previously reserved memory region
1148 * @parent: parent resource descriptor
1149 * @start: resource start address
1150 * @size: resource region size
1152 * This interface is intended for memory hot-delete. The requested region
1153 * is released from a currently busy memory resource. The requested region
1154 * must either match exactly or fit into a single busy resource entry. In
1155 * the latter case, the remaining resource is adjusted accordingly.
1156 * Existing children of the busy memory resource must be immutable in the
1160 * - Additional release conditions, such as overlapping region, can be
1161 * supported after they are confirmed as valid cases.
1162 * - When a busy memory resource gets split into two entries, the code
1163 * assumes that all children remain in the lower address entry for
1164 * simplicity. Enhance this logic when necessary.
1166 int release_mem_region_adjustable(struct resource *parent,
1167 resource_size_t start, resource_size_t size)
1169 struct resource **p;
1170 struct resource *res;
1171 struct resource *new_res;
1172 resource_size_t end;
1175 end = start + size - 1;
1176 if ((start < parent->start) || (end > parent->end))
1179 /* The alloc_resource() result gets checked later */
1180 new_res = alloc_resource(GFP_KERNEL);
1183 write_lock(&resource_lock);
1185 while ((res = *p)) {
1186 if (res->start >= end)
1189 /* look for the next resource if it does not fit into */
1190 if (res->start > start || res->end < end) {
1195 if (!(res->flags & IORESOURCE_MEM))
1198 if (!(res->flags & IORESOURCE_BUSY)) {
1203 /* found the target resource; let's adjust accordingly */
1204 if (res->start == start && res->end == end) {
1205 /* free the whole entry */
1209 } else if (res->start == start && res->end != end) {
1210 /* adjust the start */
1211 ret = __adjust_resource(res, end + 1,
1213 } else if (res->start != start && res->end == end) {
1214 /* adjust the end */
1215 ret = __adjust_resource(res, res->start,
1216 start - res->start);
1218 /* split into two entries */
1223 new_res->name = res->name;
1224 new_res->start = end + 1;
1225 new_res->end = res->end;
1226 new_res->flags = res->flags;
1227 new_res->parent = res->parent;
1228 new_res->sibling = res->sibling;
1229 new_res->child = NULL;
1231 ret = __adjust_resource(res, res->start,
1232 start - res->start);
1235 res->sibling = new_res;
1242 write_unlock(&resource_lock);
1243 free_resource(new_res);
1246 #endif /* CONFIG_MEMORY_HOTREMOVE */
1249 * Managed region resource
1251 struct region_devres {
1252 struct resource *parent;
1253 resource_size_t start;
1257 static void devm_region_release(struct device *dev, void *res)
1259 struct region_devres *this = res;
1261 __release_region(this->parent, this->start, this->n);
1264 static int devm_region_match(struct device *dev, void *res, void *match_data)
1266 struct region_devres *this = res, *match = match_data;
1268 return this->parent == match->parent &&
1269 this->start == match->start && this->n == match->n;
1272 struct resource * __devm_request_region(struct device *dev,
1273 struct resource *parent, resource_size_t start,
1274 resource_size_t n, const char *name)
1276 struct region_devres *dr = NULL;
1277 struct resource *res;
1279 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1284 dr->parent = parent;
1288 res = __request_region(parent, start, n, name, 0);
1290 devres_add(dev, dr);
1296 EXPORT_SYMBOL(__devm_request_region);
1298 void __devm_release_region(struct device *dev, struct resource *parent,
1299 resource_size_t start, resource_size_t n)
1301 struct region_devres match_data = { parent, start, n };
1303 __release_region(parent, start, n);
1304 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1307 EXPORT_SYMBOL(__devm_release_region);
1310 * Called from init/main.c to reserve IO ports.
1312 #define MAXRESERVE 4
1313 static int __init reserve_setup(char *str)
1315 static int reserved;
1316 static struct resource reserve[MAXRESERVE];
1319 unsigned int io_start, io_num;
1322 if (get_option (&str, &io_start) != 2)
1324 if (get_option (&str, &io_num) == 0)
1326 if (x < MAXRESERVE) {
1327 struct resource *res = reserve + x;
1328 res->name = "reserved";
1329 res->start = io_start;
1330 res->end = io_start + io_num - 1;
1331 res->flags = IORESOURCE_BUSY;
1333 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1340 __setup("reserve=", reserve_setup);
1343 * Check if the requested addr and size spans more than any slot in the
1344 * iomem resource tree.
1346 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1348 struct resource *p = &iomem_resource;
1352 read_lock(&resource_lock);
1353 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1355 * We can probably skip the resources without
1356 * IORESOURCE_IO attribute?
1358 if (p->start >= addr + size)
1362 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1363 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1366 * if a resource is "BUSY", it's not a hardware resource
1367 * but a driver mapping of such a resource; we don't want
1368 * to warn for those; some drivers legitimately map only
1369 * partial hardware resources. (example: vesafb)
1371 if (p->flags & IORESOURCE_BUSY)
1374 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1375 (unsigned long long)addr,
1376 (unsigned long long)(addr + size - 1),
1381 read_unlock(&resource_lock);
1386 #ifdef CONFIG_STRICT_DEVMEM
1387 static int strict_iomem_checks = 1;
1389 static int strict_iomem_checks;
1393 * check if an address is reserved in the iomem resource tree
1394 * returns 1 if reserved, 0 if not reserved.
1396 int iomem_is_exclusive(u64 addr)
1398 struct resource *p = &iomem_resource;
1401 int size = PAGE_SIZE;
1403 if (!strict_iomem_checks)
1406 addr = addr & PAGE_MASK;
1408 read_lock(&resource_lock);
1409 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1411 * We can probably skip the resources without
1412 * IORESOURCE_IO attribute?
1414 if (p->start >= addr + size)
1418 if (p->flags & IORESOURCE_BUSY &&
1419 p->flags & IORESOURCE_EXCLUSIVE) {
1424 read_unlock(&resource_lock);
1429 static int __init strict_iomem(char *str)
1431 if (strstr(str, "relaxed"))
1432 strict_iomem_checks = 0;
1433 if (strstr(str, "strict"))
1434 strict_iomem_checks = 1;
1438 __setup("iomem=", strict_iomem);