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>
25 #include <linux/resource_ext.h>
29 struct resource ioport_resource = {
32 .end = IO_SPACE_LIMIT,
33 .flags = IORESOURCE_IO,
35 EXPORT_SYMBOL(ioport_resource);
37 struct resource iomem_resource = {
41 .flags = IORESOURCE_MEM,
43 EXPORT_SYMBOL(iomem_resource);
45 /* constraints to be met while allocating resources */
46 struct resource_constraint {
47 resource_size_t min, max, align;
48 resource_size_t (*alignf)(void *, const struct resource *,
49 resource_size_t, resource_size_t);
53 static DEFINE_RWLOCK(resource_lock);
56 * For memory hotplug, there is no way to free resource entries allocated
57 * by boot mem after the system is up. So for reusing the resource entry
58 * we need to remember the resource.
60 static struct resource *bootmem_resource_free;
61 static DEFINE_SPINLOCK(bootmem_resource_lock);
63 static struct resource *next_resource(struct resource *p, bool sibling_only)
65 /* Caller wants to traverse through siblings only */
71 while (!p->sibling && p->parent)
76 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
78 struct resource *p = v;
80 return (void *)next_resource(p, false);
85 enum { MAX_IORES_LEVEL = 5 };
87 static void *r_start(struct seq_file *m, loff_t *pos)
88 __acquires(resource_lock)
90 struct resource *p = PDE_DATA(file_inode(m->file));
92 read_lock(&resource_lock);
93 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
98 static void r_stop(struct seq_file *m, void *v)
99 __releases(resource_lock)
101 read_unlock(&resource_lock);
104 static int r_show(struct seq_file *m, void *v)
106 struct resource *root = PDE_DATA(file_inode(m->file));
107 struct resource *r = v, *p;
108 unsigned long long start, end;
109 int width = root->end < 0x10000 ? 4 : 8;
112 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
113 if (p->parent == root)
116 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
123 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
127 r->name ? r->name : "<BAD>");
131 static const struct seq_operations resource_op = {
138 static int __init ioresources_init(void)
140 proc_create_seq_data("ioports", 0, NULL, &resource_op,
142 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
145 __initcall(ioresources_init);
147 #endif /* CONFIG_PROC_FS */
149 static void free_resource(struct resource *res)
154 if (!PageSlab(virt_to_head_page(res))) {
155 spin_lock(&bootmem_resource_lock);
156 res->sibling = bootmem_resource_free;
157 bootmem_resource_free = res;
158 spin_unlock(&bootmem_resource_lock);
164 static struct resource *alloc_resource(gfp_t flags)
166 struct resource *res = NULL;
168 spin_lock(&bootmem_resource_lock);
169 if (bootmem_resource_free) {
170 res = bootmem_resource_free;
171 bootmem_resource_free = res->sibling;
173 spin_unlock(&bootmem_resource_lock);
176 memset(res, 0, sizeof(struct resource));
178 res = kzalloc(sizeof(struct resource), flags);
183 /* Return the conflict entry if you can't request it */
184 static struct resource * __request_resource(struct resource *root, struct resource *new)
186 resource_size_t start = new->start;
187 resource_size_t end = new->end;
188 struct resource *tmp, **p;
192 if (start < root->start)
199 if (!tmp || tmp->start > end) {
206 if (tmp->end < start)
212 static int __release_resource(struct resource *old, bool release_child)
214 struct resource *tmp, **p, *chd;
216 p = &old->parent->child;
222 if (release_child || !(tmp->child)) {
225 for (chd = tmp->child;; chd = chd->sibling) {
226 chd->parent = tmp->parent;
231 chd->sibling = tmp->sibling;
241 static void __release_child_resources(struct resource *r)
243 struct resource *tmp, *p;
244 resource_size_t size;
254 __release_child_resources(tmp);
256 printk(KERN_DEBUG "release child resource %pR\n", tmp);
257 /* need to restore size, and keep flags */
258 size = resource_size(tmp);
264 void release_child_resources(struct resource *r)
266 write_lock(&resource_lock);
267 __release_child_resources(r);
268 write_unlock(&resource_lock);
272 * request_resource_conflict - request and reserve an I/O or memory resource
273 * @root: root resource descriptor
274 * @new: resource descriptor desired by caller
276 * Returns 0 for success, conflict resource on error.
278 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
280 struct resource *conflict;
282 write_lock(&resource_lock);
283 conflict = __request_resource(root, new);
284 write_unlock(&resource_lock);
289 * request_resource - request and reserve an I/O or memory resource
290 * @root: root resource descriptor
291 * @new: resource descriptor desired by caller
293 * Returns 0 for success, negative error code on error.
295 int request_resource(struct resource *root, struct resource *new)
297 struct resource *conflict;
299 conflict = request_resource_conflict(root, new);
300 return conflict ? -EBUSY : 0;
303 EXPORT_SYMBOL(request_resource);
306 * release_resource - release a previously reserved resource
307 * @old: resource pointer
309 int release_resource(struct resource *old)
313 write_lock(&resource_lock);
314 retval = __release_resource(old, true);
315 write_unlock(&resource_lock);
319 EXPORT_SYMBOL(release_resource);
322 * Finds the lowest iomem resource existing within [res->start.res->end).
323 * The caller must specify res->start, res->end, res->flags, and optionally
324 * desc. If found, returns 0, res is overwritten, if not found, returns -1.
325 * This function walks the whole tree and not just first level children until
326 * and unless first_level_children_only is true.
328 static int find_next_iomem_res(struct resource *res, unsigned long desc,
329 bool first_level_children_only)
331 resource_size_t start, end;
333 bool sibling_only = false;
339 BUG_ON(start >= end);
341 if (first_level_children_only)
344 read_lock(&resource_lock);
346 for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
347 if ((p->flags & res->flags) != res->flags)
349 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
351 if (p->start > end) {
355 if ((p->end >= start) && (p->start < end))
359 read_unlock(&resource_lock);
363 if (res->start < p->start)
364 res->start = p->start;
365 if (res->end > p->end)
367 res->flags = p->flags;
372 static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
373 bool first_level_children_only,
375 int (*func)(struct resource *, void *))
377 u64 orig_end = res->end;
380 while ((res->start < res->end) &&
381 !find_next_iomem_res(res, desc, first_level_children_only)) {
382 ret = (*func)(res, arg);
386 res->start = res->end + 1;
394 * Walks through iomem resources and calls func() with matching resource
395 * ranges. This walks through whole tree and not just first level children.
396 * All the memory ranges which overlap start,end and also match flags and
397 * desc are valid candidates.
399 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
400 * @flags: I/O resource flags
404 * NOTE: For a new descriptor search, define a new IORES_DESC in
405 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
407 int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
408 u64 end, void *arg, int (*func)(struct resource *, void *))
416 return __walk_iomem_res_desc(&res, desc, false, arg, func);
420 * This function calls the @func callback against all memory ranges of type
421 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
422 * Now, this function is only for System RAM, it deals with full ranges and
423 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
426 int walk_system_ram_res(u64 start, u64 end, void *arg,
427 int (*func)(struct resource *, void *))
433 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
435 return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
440 * This function calls the @func callback against all memory ranges, which
441 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
443 int walk_mem_res(u64 start, u64 end, void *arg,
444 int (*func)(struct resource *, void *))
450 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
452 return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
456 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
459 * This function calls the @func callback against all memory ranges of type
460 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
461 * It is to be used only for System RAM.
463 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
464 void *arg, int (*func)(unsigned long, unsigned long, void *))
467 unsigned long pfn, end_pfn;
471 res.start = (u64) start_pfn << PAGE_SHIFT;
472 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
473 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
475 while ((res.start < res.end) &&
476 (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
477 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
478 end_pfn = (res.end + 1) >> PAGE_SHIFT;
480 ret = (*func)(pfn, end_pfn - pfn, arg);
483 res.start = res.end + 1;
491 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
497 * This generic page_is_ram() returns true if specified address is
498 * registered as System RAM in iomem_resource list.
500 int __weak page_is_ram(unsigned long pfn)
502 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
504 EXPORT_SYMBOL_GPL(page_is_ram);
507 * region_intersects() - determine intersection of region with known resources
508 * @start: region start address
509 * @size: size of region
510 * @flags: flags of resource (in iomem_resource)
511 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
513 * Check if the specified region partially overlaps or fully eclipses a
514 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
515 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
516 * return REGION_MIXED if the region overlaps @flags/@desc and another
517 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
518 * and no other defined resource. Note that REGION_INTERSECTS is also
519 * returned in the case when the specified region overlaps RAM and undefined
522 * region_intersect() is used by memory remapping functions to ensure
523 * the user is not remapping RAM and is a vast speed up over walking
524 * through the resource table page by page.
526 int region_intersects(resource_size_t start, size_t size, unsigned long flags,
529 resource_size_t end = start + size - 1;
530 int type = 0; int other = 0;
533 read_lock(&resource_lock);
534 for (p = iomem_resource.child; p ; p = p->sibling) {
535 bool is_type = (((p->flags & flags) == flags) &&
536 ((desc == IORES_DESC_NONE) ||
539 if (start >= p->start && start <= p->end)
540 is_type ? type++ : other++;
541 if (end >= p->start && end <= p->end)
542 is_type ? type++ : other++;
543 if (p->start >= start && p->end <= end)
544 is_type ? type++ : other++;
546 read_unlock(&resource_lock);
549 return type ? REGION_INTERSECTS : REGION_DISJOINT;
554 return REGION_DISJOINT;
556 EXPORT_SYMBOL_GPL(region_intersects);
558 void __weak arch_remove_reservations(struct resource *avail)
562 static resource_size_t simple_align_resource(void *data,
563 const struct resource *avail,
564 resource_size_t size,
565 resource_size_t align)
570 static void resource_clip(struct resource *res, resource_size_t min,
573 if (res->start < min)
580 * Find empty slot in the resource tree with the given range and
581 * alignment constraints
583 static int __find_resource(struct resource *root, struct resource *old,
584 struct resource *new,
585 resource_size_t size,
586 struct resource_constraint *constraint)
588 struct resource *this = root->child;
589 struct resource tmp = *new, avail, alloc;
591 tmp.start = root->start;
593 * Skip past an allocated resource that starts at 0, since the assignment
594 * of this->start - 1 to tmp->end below would cause an underflow.
596 if (this && this->start == root->start) {
597 tmp.start = (this == old) ? old->start : this->end + 1;
598 this = this->sibling;
602 tmp.end = (this == old) ? this->end : this->start - 1;
606 if (tmp.end < tmp.start)
609 resource_clip(&tmp, constraint->min, constraint->max);
610 arch_remove_reservations(&tmp);
612 /* Check for overflow after ALIGN() */
613 avail.start = ALIGN(tmp.start, constraint->align);
615 avail.flags = new->flags & ~IORESOURCE_UNSET;
616 if (avail.start >= tmp.start) {
617 alloc.flags = avail.flags;
618 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
619 size, constraint->align);
620 alloc.end = alloc.start + size - 1;
621 if (alloc.start <= alloc.end &&
622 resource_contains(&avail, &alloc)) {
623 new->start = alloc.start;
624 new->end = alloc.end;
629 next: if (!this || this->end == root->end)
633 tmp.start = this->end + 1;
634 this = this->sibling;
640 * Find empty slot in the resource tree given range and alignment.
642 static int find_resource(struct resource *root, struct resource *new,
643 resource_size_t size,
644 struct resource_constraint *constraint)
646 return __find_resource(root, NULL, new, size, constraint);
650 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
651 * The resource will be relocated if the new size cannot be reallocated in the
654 * @root: root resource descriptor
655 * @old: resource descriptor desired by caller
656 * @newsize: new size of the resource descriptor
657 * @constraint: the size and alignment constraints to be met.
659 static int reallocate_resource(struct resource *root, struct resource *old,
660 resource_size_t newsize,
661 struct resource_constraint *constraint)
664 struct resource new = *old;
665 struct resource *conflict;
667 write_lock(&resource_lock);
669 if ((err = __find_resource(root, old, &new, newsize, constraint)))
672 if (resource_contains(&new, old)) {
673 old->start = new.start;
683 if (resource_contains(old, &new)) {
684 old->start = new.start;
687 __release_resource(old, true);
689 conflict = __request_resource(root, old);
693 write_unlock(&resource_lock);
699 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
700 * The resource will be reallocated with a new size if it was already allocated
701 * @root: root resource descriptor
702 * @new: resource descriptor desired by caller
703 * @size: requested resource region size
704 * @min: minimum boundary to allocate
705 * @max: maximum boundary to allocate
706 * @align: alignment requested, in bytes
707 * @alignf: alignment function, optional, called if not NULL
708 * @alignf_data: arbitrary data to pass to the @alignf function
710 int allocate_resource(struct resource *root, struct resource *new,
711 resource_size_t size, resource_size_t min,
712 resource_size_t max, resource_size_t align,
713 resource_size_t (*alignf)(void *,
714 const struct resource *,
720 struct resource_constraint constraint;
723 alignf = simple_align_resource;
725 constraint.min = min;
726 constraint.max = max;
727 constraint.align = align;
728 constraint.alignf = alignf;
729 constraint.alignf_data = alignf_data;
732 /* resource is already allocated, try reallocating with
733 the new constraints */
734 return reallocate_resource(root, new, size, &constraint);
737 write_lock(&resource_lock);
738 err = find_resource(root, new, size, &constraint);
739 if (err >= 0 && __request_resource(root, new))
741 write_unlock(&resource_lock);
745 EXPORT_SYMBOL(allocate_resource);
748 * lookup_resource - find an existing resource by a resource start address
749 * @root: root resource descriptor
750 * @start: resource start address
752 * Returns a pointer to the resource if found, NULL otherwise
754 struct resource *lookup_resource(struct resource *root, resource_size_t start)
756 struct resource *res;
758 read_lock(&resource_lock);
759 for (res = root->child; res; res = res->sibling) {
760 if (res->start == start)
763 read_unlock(&resource_lock);
769 * Insert a resource into the resource tree. If successful, return NULL,
770 * otherwise return the conflicting resource (compare to __request_resource())
772 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
774 struct resource *first, *next;
776 for (;; parent = first) {
777 first = __request_resource(parent, new);
783 if (WARN_ON(first == new)) /* duplicated insertion */
786 if ((first->start > new->start) || (first->end < new->end))
788 if ((first->start == new->start) && (first->end == new->end))
792 for (next = first; ; next = next->sibling) {
793 /* Partial overlap? Bad, and unfixable */
794 if (next->start < new->start || next->end > new->end)
798 if (next->sibling->start > new->end)
802 new->parent = parent;
803 new->sibling = next->sibling;
806 next->sibling = NULL;
807 for (next = first; next; next = next->sibling)
810 if (parent->child == first) {
813 next = parent->child;
814 while (next->sibling != first)
815 next = next->sibling;
822 * insert_resource_conflict - Inserts resource in the resource tree
823 * @parent: parent of the new resource
824 * @new: new resource to insert
826 * Returns 0 on success, conflict resource if the resource can't be inserted.
828 * This function is equivalent to request_resource_conflict when no conflict
829 * happens. If a conflict happens, and the conflicting resources
830 * entirely fit within the range of the new resource, then the new
831 * resource is inserted and the conflicting resources become children of
834 * This function is intended for producers of resources, such as FW modules
837 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
839 struct resource *conflict;
841 write_lock(&resource_lock);
842 conflict = __insert_resource(parent, new);
843 write_unlock(&resource_lock);
848 * insert_resource - Inserts a resource in the resource tree
849 * @parent: parent of the new resource
850 * @new: new resource to insert
852 * Returns 0 on success, -EBUSY if the resource can't be inserted.
854 * This function is intended for producers of resources, such as FW modules
857 int insert_resource(struct resource *parent, struct resource *new)
859 struct resource *conflict;
861 conflict = insert_resource_conflict(parent, new);
862 return conflict ? -EBUSY : 0;
864 EXPORT_SYMBOL_GPL(insert_resource);
867 * insert_resource_expand_to_fit - Insert a resource into the resource tree
868 * @root: root resource descriptor
869 * @new: new resource to insert
871 * Insert a resource into the resource tree, possibly expanding it in order
872 * to make it encompass any conflicting resources.
874 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
879 write_lock(&resource_lock);
881 struct resource *conflict;
883 conflict = __insert_resource(root, new);
886 if (conflict == root)
889 /* Ok, expand resource to cover the conflict, then try again .. */
890 if (conflict->start < new->start)
891 new->start = conflict->start;
892 if (conflict->end > new->end)
893 new->end = conflict->end;
895 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
897 write_unlock(&resource_lock);
901 * remove_resource - Remove a resource in the resource tree
902 * @old: resource to remove
904 * Returns 0 on success, -EINVAL if the resource is not valid.
906 * This function removes a resource previously inserted by insert_resource()
907 * or insert_resource_conflict(), and moves the children (if any) up to
908 * where they were before. insert_resource() and insert_resource_conflict()
909 * insert a new resource, and move any conflicting resources down to the
910 * children of the new resource.
912 * insert_resource(), insert_resource_conflict() and remove_resource() are
913 * intended for producers of resources, such as FW modules and bus drivers.
915 int remove_resource(struct resource *old)
919 write_lock(&resource_lock);
920 retval = __release_resource(old, false);
921 write_unlock(&resource_lock);
924 EXPORT_SYMBOL_GPL(remove_resource);
926 static int __adjust_resource(struct resource *res, resource_size_t start,
927 resource_size_t size)
929 struct resource *tmp, *parent = res->parent;
930 resource_size_t end = start + size - 1;
936 if ((start < parent->start) || (end > parent->end))
939 if (res->sibling && (res->sibling->start <= end))
944 while (tmp->sibling != res)
946 if (start <= tmp->end)
951 for (tmp = res->child; tmp; tmp = tmp->sibling)
952 if ((tmp->start < start) || (tmp->end > end))
964 * adjust_resource - modify a resource's start and size
965 * @res: resource to modify
966 * @start: new start value
969 * Given an existing resource, change its start and size to match the
970 * arguments. Returns 0 on success, -EBUSY if it can't fit.
971 * Existing children of the resource are assumed to be immutable.
973 int adjust_resource(struct resource *res, resource_size_t start,
974 resource_size_t size)
978 write_lock(&resource_lock);
979 result = __adjust_resource(res, start, size);
980 write_unlock(&resource_lock);
983 EXPORT_SYMBOL(adjust_resource);
985 static void __init __reserve_region_with_split(struct resource *root,
986 resource_size_t start, resource_size_t end,
989 struct resource *parent = root;
990 struct resource *conflict;
991 struct resource *res = alloc_resource(GFP_ATOMIC);
992 struct resource *next_res = NULL;
993 int type = resource_type(root);
1001 res->flags = type | IORESOURCE_BUSY;
1002 res->desc = IORES_DESC_NONE;
1006 conflict = __request_resource(parent, res);
1015 /* conflict covered whole area */
1016 if (conflict->start <= res->start &&
1017 conflict->end >= res->end) {
1023 /* failed, split and try again */
1024 if (conflict->start > res->start) {
1026 res->end = conflict->start - 1;
1027 if (conflict->end < end) {
1028 next_res = alloc_resource(GFP_ATOMIC);
1033 next_res->name = name;
1034 next_res->start = conflict->end + 1;
1035 next_res->end = end;
1036 next_res->flags = type | IORESOURCE_BUSY;
1037 next_res->desc = IORES_DESC_NONE;
1040 res->start = conflict->end + 1;
1046 void __init reserve_region_with_split(struct resource *root,
1047 resource_size_t start, resource_size_t end,
1052 write_lock(&resource_lock);
1053 if (root->start > start || root->end < end) {
1054 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1055 (unsigned long long)start, (unsigned long long)end,
1057 if (start > root->end || end < root->start)
1060 if (end > root->end)
1062 if (start < root->start)
1063 start = root->start;
1064 pr_err("fixing request to [0x%llx-0x%llx]\n",
1065 (unsigned long long)start,
1066 (unsigned long long)end);
1071 __reserve_region_with_split(root, start, end, name);
1072 write_unlock(&resource_lock);
1076 * resource_alignment - calculate resource's alignment
1077 * @res: resource pointer
1079 * Returns alignment on success, 0 (invalid alignment) on failure.
1081 resource_size_t resource_alignment(struct resource *res)
1083 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1084 case IORESOURCE_SIZEALIGN:
1085 return resource_size(res);
1086 case IORESOURCE_STARTALIGN:
1094 * This is compatibility stuff for IO resources.
1096 * Note how this, unlike the above, knows about
1097 * the IO flag meanings (busy etc).
1099 * request_region creates a new busy region.
1101 * release_region releases a matching busy region.
1104 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1107 * __request_region - create a new busy resource region
1108 * @parent: parent resource descriptor
1109 * @start: resource start address
1110 * @n: resource region size
1111 * @name: reserving caller's ID string
1112 * @flags: IO resource flags
1114 struct resource * __request_region(struct resource *parent,
1115 resource_size_t start, resource_size_t n,
1116 const char *name, int flags)
1118 DECLARE_WAITQUEUE(wait, current);
1119 struct resource *res = alloc_resource(GFP_KERNEL);
1126 res->end = start + n - 1;
1128 write_lock(&resource_lock);
1131 struct resource *conflict;
1133 res->flags = resource_type(parent) | resource_ext_type(parent);
1134 res->flags |= IORESOURCE_BUSY | flags;
1135 res->desc = parent->desc;
1137 conflict = __request_resource(parent, res);
1140 if (conflict != parent) {
1141 if (!(conflict->flags & IORESOURCE_BUSY)) {
1146 if (conflict->flags & flags & IORESOURCE_MUXED) {
1147 add_wait_queue(&muxed_resource_wait, &wait);
1148 write_unlock(&resource_lock);
1149 set_current_state(TASK_UNINTERRUPTIBLE);
1151 remove_wait_queue(&muxed_resource_wait, &wait);
1152 write_lock(&resource_lock);
1155 /* Uhhuh, that didn't work out.. */
1160 write_unlock(&resource_lock);
1163 EXPORT_SYMBOL(__request_region);
1166 * __release_region - release a previously reserved resource region
1167 * @parent: parent resource descriptor
1168 * @start: resource start address
1169 * @n: resource region size
1171 * The described resource region must match a currently busy region.
1173 void __release_region(struct resource *parent, resource_size_t start,
1176 struct resource **p;
1177 resource_size_t end;
1180 end = start + n - 1;
1182 write_lock(&resource_lock);
1185 struct resource *res = *p;
1189 if (res->start <= start && res->end >= end) {
1190 if (!(res->flags & IORESOURCE_BUSY)) {
1194 if (res->start != start || res->end != end)
1197 write_unlock(&resource_lock);
1198 if (res->flags & IORESOURCE_MUXED)
1199 wake_up(&muxed_resource_wait);
1206 write_unlock(&resource_lock);
1208 printk(KERN_WARNING "Trying to free nonexistent resource "
1209 "<%016llx-%016llx>\n", (unsigned long long)start,
1210 (unsigned long long)end);
1212 EXPORT_SYMBOL(__release_region);
1214 #ifdef CONFIG_MEMORY_HOTREMOVE
1216 * release_mem_region_adjustable - release a previously reserved memory region
1217 * @parent: parent resource descriptor
1218 * @start: resource start address
1219 * @size: resource region size
1221 * This interface is intended for memory hot-delete. The requested region
1222 * is released from a currently busy memory resource. The requested region
1223 * must either match exactly or fit into a single busy resource entry. In
1224 * the latter case, the remaining resource is adjusted accordingly.
1225 * Existing children of the busy memory resource must be immutable in the
1229 * - Additional release conditions, such as overlapping region, can be
1230 * supported after they are confirmed as valid cases.
1231 * - When a busy memory resource gets split into two entries, the code
1232 * assumes that all children remain in the lower address entry for
1233 * simplicity. Enhance this logic when necessary.
1235 int release_mem_region_adjustable(struct resource *parent,
1236 resource_size_t start, resource_size_t size)
1238 struct resource **p;
1239 struct resource *res;
1240 struct resource *new_res;
1241 resource_size_t end;
1244 end = start + size - 1;
1245 if ((start < parent->start) || (end > parent->end))
1248 /* The alloc_resource() result gets checked later */
1249 new_res = alloc_resource(GFP_KERNEL);
1252 write_lock(&resource_lock);
1254 while ((res = *p)) {
1255 if (res->start >= end)
1258 /* look for the next resource if it does not fit into */
1259 if (res->start > start || res->end < end) {
1264 if (!(res->flags & IORESOURCE_MEM))
1267 if (!(res->flags & IORESOURCE_BUSY)) {
1272 /* found the target resource; let's adjust accordingly */
1273 if (res->start == start && res->end == end) {
1274 /* free the whole entry */
1278 } else if (res->start == start && res->end != end) {
1279 /* adjust the start */
1280 ret = __adjust_resource(res, end + 1,
1282 } else if (res->start != start && res->end == end) {
1283 /* adjust the end */
1284 ret = __adjust_resource(res, res->start,
1285 start - res->start);
1287 /* split into two entries */
1292 new_res->name = res->name;
1293 new_res->start = end + 1;
1294 new_res->end = res->end;
1295 new_res->flags = res->flags;
1296 new_res->desc = res->desc;
1297 new_res->parent = res->parent;
1298 new_res->sibling = res->sibling;
1299 new_res->child = NULL;
1301 ret = __adjust_resource(res, res->start,
1302 start - res->start);
1305 res->sibling = new_res;
1312 write_unlock(&resource_lock);
1313 free_resource(new_res);
1316 #endif /* CONFIG_MEMORY_HOTREMOVE */
1319 * Managed region resource
1321 static void devm_resource_release(struct device *dev, void *ptr)
1323 struct resource **r = ptr;
1325 release_resource(*r);
1329 * devm_request_resource() - request and reserve an I/O or memory resource
1330 * @dev: device for which to request the resource
1331 * @root: root of the resource tree from which to request the resource
1332 * @new: descriptor of the resource to request
1334 * This is a device-managed version of request_resource(). There is usually
1335 * no need to release resources requested by this function explicitly since
1336 * that will be taken care of when the device is unbound from its driver.
1337 * If for some reason the resource needs to be released explicitly, because
1338 * of ordering issues for example, drivers must call devm_release_resource()
1339 * rather than the regular release_resource().
1341 * When a conflict is detected between any existing resources and the newly
1342 * requested resource, an error message will be printed.
1344 * Returns 0 on success or a negative error code on failure.
1346 int devm_request_resource(struct device *dev, struct resource *root,
1347 struct resource *new)
1349 struct resource *conflict, **ptr;
1351 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1357 conflict = request_resource_conflict(root, new);
1359 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1360 new, conflict->name, conflict);
1365 devres_add(dev, ptr);
1368 EXPORT_SYMBOL(devm_request_resource);
1370 static int devm_resource_match(struct device *dev, void *res, void *data)
1372 struct resource **ptr = res;
1374 return *ptr == data;
1378 * devm_release_resource() - release a previously requested resource
1379 * @dev: device for which to release the resource
1380 * @new: descriptor of the resource to release
1382 * Releases a resource previously requested using devm_request_resource().
1384 void devm_release_resource(struct device *dev, struct resource *new)
1386 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1389 EXPORT_SYMBOL(devm_release_resource);
1391 struct region_devres {
1392 struct resource *parent;
1393 resource_size_t start;
1397 static void devm_region_release(struct device *dev, void *res)
1399 struct region_devres *this = res;
1401 __release_region(this->parent, this->start, this->n);
1404 static int devm_region_match(struct device *dev, void *res, void *match_data)
1406 struct region_devres *this = res, *match = match_data;
1408 return this->parent == match->parent &&
1409 this->start == match->start && this->n == match->n;
1412 struct resource * __devm_request_region(struct device *dev,
1413 struct resource *parent, resource_size_t start,
1414 resource_size_t n, const char *name)
1416 struct region_devres *dr = NULL;
1417 struct resource *res;
1419 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1424 dr->parent = parent;
1428 res = __request_region(parent, start, n, name, 0);
1430 devres_add(dev, dr);
1436 EXPORT_SYMBOL(__devm_request_region);
1438 void __devm_release_region(struct device *dev, struct resource *parent,
1439 resource_size_t start, resource_size_t n)
1441 struct region_devres match_data = { parent, start, n };
1443 __release_region(parent, start, n);
1444 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1447 EXPORT_SYMBOL(__devm_release_region);
1450 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1452 #define MAXRESERVE 4
1453 static int __init reserve_setup(char *str)
1455 static int reserved;
1456 static struct resource reserve[MAXRESERVE];
1459 unsigned int io_start, io_num;
1461 struct resource *parent;
1463 if (get_option(&str, &io_start) != 2)
1465 if (get_option(&str, &io_num) == 0)
1467 if (x < MAXRESERVE) {
1468 struct resource *res = reserve + x;
1471 * If the region starts below 0x10000, we assume it's
1472 * I/O port space; otherwise assume it's memory.
1474 if (io_start < 0x10000) {
1475 res->flags = IORESOURCE_IO;
1476 parent = &ioport_resource;
1478 res->flags = IORESOURCE_MEM;
1479 parent = &iomem_resource;
1481 res->name = "reserved";
1482 res->start = io_start;
1483 res->end = io_start + io_num - 1;
1484 res->flags |= IORESOURCE_BUSY;
1485 res->desc = IORES_DESC_NONE;
1487 if (request_resource(parent, res) == 0)
1493 __setup("reserve=", reserve_setup);
1496 * Check if the requested addr and size spans more than any slot in the
1497 * iomem resource tree.
1499 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1501 struct resource *p = &iomem_resource;
1505 read_lock(&resource_lock);
1506 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1508 * We can probably skip the resources without
1509 * IORESOURCE_IO attribute?
1511 if (p->start >= addr + size)
1515 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1516 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1519 * if a resource is "BUSY", it's not a hardware resource
1520 * but a driver mapping of such a resource; we don't want
1521 * to warn for those; some drivers legitimately map only
1522 * partial hardware resources. (example: vesafb)
1524 if (p->flags & IORESOURCE_BUSY)
1527 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1528 (unsigned long long)addr,
1529 (unsigned long long)(addr + size - 1),
1534 read_unlock(&resource_lock);
1539 #ifdef CONFIG_STRICT_DEVMEM
1540 static int strict_iomem_checks = 1;
1542 static int strict_iomem_checks;
1546 * check if an address is reserved in the iomem resource tree
1547 * returns true if reserved, false if not reserved.
1549 bool iomem_is_exclusive(u64 addr)
1551 struct resource *p = &iomem_resource;
1554 int size = PAGE_SIZE;
1556 if (!strict_iomem_checks)
1559 addr = addr & PAGE_MASK;
1561 read_lock(&resource_lock);
1562 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1564 * We can probably skip the resources without
1565 * IORESOURCE_IO attribute?
1567 if (p->start >= addr + size)
1572 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1573 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1576 if ((p->flags & IORESOURCE_BUSY) == 0)
1578 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1579 || p->flags & IORESOURCE_EXCLUSIVE) {
1584 read_unlock(&resource_lock);
1589 struct resource_entry *resource_list_create_entry(struct resource *res,
1592 struct resource_entry *entry;
1594 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1596 INIT_LIST_HEAD(&entry->node);
1597 entry->res = res ? res : &entry->__res;
1602 EXPORT_SYMBOL(resource_list_create_entry);
1604 void resource_list_free(struct list_head *head)
1606 struct resource_entry *entry, *tmp;
1608 list_for_each_entry_safe(entry, tmp, head, node)
1609 resource_list_destroy_entry(entry);
1611 EXPORT_SYMBOL(resource_list_free);
1613 static int __init strict_iomem(char *str)
1615 if (strstr(str, "relaxed"))
1616 strict_iomem_checks = 0;
1617 if (strstr(str, "strict"))
1618 strict_iomem_checks = 1;
1622 __setup("iomem=", strict_iomem);