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 = m->private;
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 = m->private;
107 struct resource *r = v, *p;
108 int width = root->end < 0x10000 ? 4 : 8;
111 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
112 if (p->parent == root)
114 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
116 width, (unsigned long long) r->start,
117 width, (unsigned long long) r->end,
118 r->name ? r->name : "<BAD>");
122 static const struct seq_operations resource_op = {
129 static int ioports_open(struct inode *inode, struct file *file)
131 int res = seq_open(file, &resource_op);
133 struct seq_file *m = file->private_data;
134 m->private = &ioport_resource;
139 static int iomem_open(struct inode *inode, struct file *file)
141 int res = seq_open(file, &resource_op);
143 struct seq_file *m = file->private_data;
144 m->private = &iomem_resource;
149 static const struct file_operations proc_ioports_operations = {
150 .open = ioports_open,
153 .release = seq_release,
156 static const struct file_operations proc_iomem_operations = {
160 .release = seq_release,
163 static int __init ioresources_init(void)
165 proc_create("ioports", 0, NULL, &proc_ioports_operations);
166 proc_create("iomem", 0, NULL, &proc_iomem_operations);
169 __initcall(ioresources_init);
171 #endif /* CONFIG_PROC_FS */
173 static void free_resource(struct resource *res)
178 if (!PageSlab(virt_to_head_page(res))) {
179 spin_lock(&bootmem_resource_lock);
180 res->sibling = bootmem_resource_free;
181 bootmem_resource_free = res;
182 spin_unlock(&bootmem_resource_lock);
188 static struct resource *alloc_resource(gfp_t flags)
190 struct resource *res = NULL;
192 spin_lock(&bootmem_resource_lock);
193 if (bootmem_resource_free) {
194 res = bootmem_resource_free;
195 bootmem_resource_free = res->sibling;
197 spin_unlock(&bootmem_resource_lock);
200 memset(res, 0, sizeof(struct resource));
202 res = kzalloc(sizeof(struct resource), flags);
207 /* Return the conflict entry if you can't request it */
208 static struct resource * __request_resource(struct resource *root, struct resource *new)
210 resource_size_t start = new->start;
211 resource_size_t end = new->end;
212 struct resource *tmp, **p;
216 if (start < root->start)
223 if (!tmp || tmp->start > end) {
230 if (tmp->end < start)
236 static int __release_resource(struct resource *old)
238 struct resource *tmp, **p;
240 p = &old->parent->child;
255 static void __release_child_resources(struct resource *r)
257 struct resource *tmp, *p;
258 resource_size_t size;
268 __release_child_resources(tmp);
270 printk(KERN_DEBUG "release child resource %pR\n", tmp);
271 /* need to restore size, and keep flags */
272 size = resource_size(tmp);
278 void release_child_resources(struct resource *r)
280 write_lock(&resource_lock);
281 __release_child_resources(r);
282 write_unlock(&resource_lock);
286 * request_resource_conflict - request and reserve an I/O or memory resource
287 * @root: root resource descriptor
288 * @new: resource descriptor desired by caller
290 * Returns 0 for success, conflict resource on error.
292 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
294 struct resource *conflict;
296 write_lock(&resource_lock);
297 conflict = __request_resource(root, new);
298 write_unlock(&resource_lock);
303 * request_resource - request and reserve an I/O or memory resource
304 * @root: root resource descriptor
305 * @new: resource descriptor desired by caller
307 * Returns 0 for success, negative error code on error.
309 int request_resource(struct resource *root, struct resource *new)
311 struct resource *conflict;
313 conflict = request_resource_conflict(root, new);
314 return conflict ? -EBUSY : 0;
317 EXPORT_SYMBOL(request_resource);
320 * release_resource - release a previously reserved resource
321 * @old: resource pointer
323 int release_resource(struct resource *old)
327 write_lock(&resource_lock);
328 retval = __release_resource(old);
329 write_unlock(&resource_lock);
333 EXPORT_SYMBOL(release_resource);
336 * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
337 * the caller must specify res->start, res->end, res->flags and "name".
338 * If found, returns 0, res is overwritten, if not found, returns -1.
339 * This walks through whole tree and not just first level children
340 * until and unless first_level_children_only is true.
342 static int find_next_iomem_res(struct resource *res, char *name,
343 bool first_level_children_only)
345 resource_size_t start, end;
347 bool sibling_only = false;
353 BUG_ON(start >= end);
355 if (first_level_children_only)
358 read_lock(&resource_lock);
360 for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
361 if (p->flags != res->flags)
363 if (name && strcmp(p->name, name))
365 if (p->start > end) {
369 if ((p->end >= start) && (p->start < end))
373 read_unlock(&resource_lock);
377 if (res->start < p->start)
378 res->start = p->start;
379 if (res->end > p->end)
385 * Walks through iomem resources and calls func() with matching resource
386 * ranges. This walks through whole tree and not just first level children.
387 * All the memory ranges which overlap start,end and also match flags and
388 * name are valid candidates.
390 * @name: name of resource
391 * @flags: resource flags
395 int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
396 void *arg, int (*func)(u64, u64, void *))
406 while ((res.start < res.end) &&
407 (!find_next_iomem_res(&res, name, false))) {
408 ret = (*func)(res.start, res.end, arg);
411 res.start = res.end + 1;
418 * This function calls callback against all memory range of "System RAM"
419 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
420 * Now, this function is only for "System RAM". This function deals with
421 * full ranges and not pfn. If resources are not pfn aligned, dealing
422 * with pfn can truncate ranges.
424 int walk_system_ram_res(u64 start, u64 end, void *arg,
425 int (*func)(u64, u64, void *))
433 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
435 while ((res.start < res.end) &&
436 (!find_next_iomem_res(&res, "System RAM", true))) {
437 ret = (*func)(res.start, res.end, arg);
440 res.start = res.end + 1;
446 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
449 * This function calls callback against all memory range of "System RAM"
450 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
451 * Now, this function is only for "System RAM".
453 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
454 void *arg, int (*func)(unsigned long, unsigned long, void *))
457 unsigned long pfn, end_pfn;
461 res.start = (u64) start_pfn << PAGE_SHIFT;
462 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
463 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
465 while ((res.start < res.end) &&
466 (find_next_iomem_res(&res, "System RAM", true) >= 0)) {
467 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
468 end_pfn = (res.end + 1) >> PAGE_SHIFT;
470 ret = (*func)(pfn, end_pfn - pfn, arg);
473 res.start = res.end + 1;
481 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
486 * This generic page_is_ram() returns true if specified address is
487 * registered as "System RAM" in iomem_resource list.
489 int __weak page_is_ram(unsigned long pfn)
491 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
493 EXPORT_SYMBOL_GPL(page_is_ram);
496 * Search for a resouce entry that fully contains the specified region.
497 * If found, return 1 if it is RAM, 0 if not.
498 * If not found, or region is not fully contained, return -1
500 * Used by the ioremap functions to ensure the user is not remapping RAM and is
501 * a vast speed up over walking through the resource table page by page.
503 int region_is_ram(resource_size_t start, unsigned long size)
506 resource_size_t end = start + size - 1;
507 int flags = IORESOURCE_MEM | IORESOURCE_BUSY;
508 const char *name = "System RAM";
511 read_lock(&resource_lock);
512 for (p = iomem_resource.child; p ; p = p->sibling) {
516 if (p->start <= start && end <= p->end) {
517 /* resource fully contains region */
518 if ((p->flags != flags) || strcmp(p->name, name))
525 break; /* not found */
527 read_unlock(&resource_lock);
531 void __weak arch_remove_reservations(struct resource *avail)
535 static resource_size_t simple_align_resource(void *data,
536 const struct resource *avail,
537 resource_size_t size,
538 resource_size_t align)
543 static void resource_clip(struct resource *res, resource_size_t min,
546 if (res->start < min)
553 * Find empty slot in the resource tree with the given range and
554 * alignment constraints
556 static int __find_resource(struct resource *root, struct resource *old,
557 struct resource *new,
558 resource_size_t size,
559 struct resource_constraint *constraint)
561 struct resource *this = root->child;
562 struct resource tmp = *new, avail, alloc;
564 tmp.start = root->start;
566 * Skip past an allocated resource that starts at 0, since the assignment
567 * of this->start - 1 to tmp->end below would cause an underflow.
569 if (this && this->start == root->start) {
570 tmp.start = (this == old) ? old->start : this->end + 1;
571 this = this->sibling;
575 tmp.end = (this == old) ? this->end : this->start - 1;
579 if (tmp.end < tmp.start)
582 resource_clip(&tmp, constraint->min, constraint->max);
583 arch_remove_reservations(&tmp);
585 /* Check for overflow after ALIGN() */
586 avail.start = ALIGN(tmp.start, constraint->align);
588 avail.flags = new->flags & ~IORESOURCE_UNSET;
589 if (avail.start >= tmp.start) {
590 alloc.flags = avail.flags;
591 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
592 size, constraint->align);
593 alloc.end = alloc.start + size - 1;
594 if (resource_contains(&avail, &alloc)) {
595 new->start = alloc.start;
596 new->end = alloc.end;
601 next: if (!this || this->end == root->end)
605 tmp.start = this->end + 1;
606 this = this->sibling;
612 * Find empty slot in the resource tree given range and alignment.
614 static int find_resource(struct resource *root, struct resource *new,
615 resource_size_t size,
616 struct resource_constraint *constraint)
618 return __find_resource(root, NULL, new, size, constraint);
622 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
623 * The resource will be relocated if the new size cannot be reallocated in the
626 * @root: root resource descriptor
627 * @old: resource descriptor desired by caller
628 * @newsize: new size of the resource descriptor
629 * @constraint: the size and alignment constraints to be met.
631 static int reallocate_resource(struct resource *root, struct resource *old,
632 resource_size_t newsize,
633 struct resource_constraint *constraint)
636 struct resource new = *old;
637 struct resource *conflict;
639 write_lock(&resource_lock);
641 if ((err = __find_resource(root, old, &new, newsize, constraint)))
644 if (resource_contains(&new, old)) {
645 old->start = new.start;
655 if (resource_contains(old, &new)) {
656 old->start = new.start;
659 __release_resource(old);
661 conflict = __request_resource(root, old);
665 write_unlock(&resource_lock);
671 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
672 * The resource will be reallocated with a new size if it was already allocated
673 * @root: root resource descriptor
674 * @new: resource descriptor desired by caller
675 * @size: requested resource region size
676 * @min: minimum boundary to allocate
677 * @max: maximum boundary to allocate
678 * @align: alignment requested, in bytes
679 * @alignf: alignment function, optional, called if not NULL
680 * @alignf_data: arbitrary data to pass to the @alignf function
682 int allocate_resource(struct resource *root, struct resource *new,
683 resource_size_t size, resource_size_t min,
684 resource_size_t max, resource_size_t align,
685 resource_size_t (*alignf)(void *,
686 const struct resource *,
692 struct resource_constraint constraint;
695 alignf = simple_align_resource;
697 constraint.min = min;
698 constraint.max = max;
699 constraint.align = align;
700 constraint.alignf = alignf;
701 constraint.alignf_data = alignf_data;
704 /* resource is already allocated, try reallocating with
705 the new constraints */
706 return reallocate_resource(root, new, size, &constraint);
709 write_lock(&resource_lock);
710 err = find_resource(root, new, size, &constraint);
711 if (err >= 0 && __request_resource(root, new))
713 write_unlock(&resource_lock);
717 EXPORT_SYMBOL(allocate_resource);
720 * lookup_resource - find an existing resource by a resource start address
721 * @root: root resource descriptor
722 * @start: resource start address
724 * Returns a pointer to the resource if found, NULL otherwise
726 struct resource *lookup_resource(struct resource *root, resource_size_t start)
728 struct resource *res;
730 read_lock(&resource_lock);
731 for (res = root->child; res; res = res->sibling) {
732 if (res->start == start)
735 read_unlock(&resource_lock);
741 * Insert a resource into the resource tree. If successful, return NULL,
742 * otherwise return the conflicting resource (compare to __request_resource())
744 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
746 struct resource *first, *next;
748 for (;; parent = first) {
749 first = __request_resource(parent, new);
755 if (WARN_ON(first == new)) /* duplicated insertion */
758 if ((first->start > new->start) || (first->end < new->end))
760 if ((first->start == new->start) && (first->end == new->end))
764 for (next = first; ; next = next->sibling) {
765 /* Partial overlap? Bad, and unfixable */
766 if (next->start < new->start || next->end > new->end)
770 if (next->sibling->start > new->end)
774 new->parent = parent;
775 new->sibling = next->sibling;
778 next->sibling = NULL;
779 for (next = first; next; next = next->sibling)
782 if (parent->child == first) {
785 next = parent->child;
786 while (next->sibling != first)
787 next = next->sibling;
794 * insert_resource_conflict - Inserts resource in the resource tree
795 * @parent: parent of the new resource
796 * @new: new resource to insert
798 * Returns 0 on success, conflict resource if the resource can't be inserted.
800 * This function is equivalent to request_resource_conflict when no conflict
801 * happens. If a conflict happens, and the conflicting resources
802 * entirely fit within the range of the new resource, then the new
803 * resource is inserted and the conflicting resources become children of
806 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
808 struct resource *conflict;
810 write_lock(&resource_lock);
811 conflict = __insert_resource(parent, new);
812 write_unlock(&resource_lock);
817 * insert_resource - Inserts a resource in the resource tree
818 * @parent: parent of the new resource
819 * @new: new resource to insert
821 * Returns 0 on success, -EBUSY if the resource can't be inserted.
823 int insert_resource(struct resource *parent, struct resource *new)
825 struct resource *conflict;
827 conflict = insert_resource_conflict(parent, new);
828 return conflict ? -EBUSY : 0;
832 * insert_resource_expand_to_fit - Insert a resource into the resource tree
833 * @root: root resource descriptor
834 * @new: new resource to insert
836 * Insert a resource into the resource tree, possibly expanding it in order
837 * to make it encompass any conflicting resources.
839 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
844 write_lock(&resource_lock);
846 struct resource *conflict;
848 conflict = __insert_resource(root, new);
851 if (conflict == root)
854 /* Ok, expand resource to cover the conflict, then try again .. */
855 if (conflict->start < new->start)
856 new->start = conflict->start;
857 if (conflict->end > new->end)
858 new->end = conflict->end;
860 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
862 write_unlock(&resource_lock);
865 static int __adjust_resource(struct resource *res, resource_size_t start,
866 resource_size_t size)
868 struct resource *tmp, *parent = res->parent;
869 resource_size_t end = start + size - 1;
875 if ((start < parent->start) || (end > parent->end))
878 if (res->sibling && (res->sibling->start <= end))
883 while (tmp->sibling != res)
885 if (start <= tmp->end)
890 for (tmp = res->child; tmp; tmp = tmp->sibling)
891 if ((tmp->start < start) || (tmp->end > end))
903 * adjust_resource - modify a resource's start and size
904 * @res: resource to modify
905 * @start: new start value
908 * Given an existing resource, change its start and size to match the
909 * arguments. Returns 0 on success, -EBUSY if it can't fit.
910 * Existing children of the resource are assumed to be immutable.
912 int adjust_resource(struct resource *res, resource_size_t start,
913 resource_size_t size)
917 write_lock(&resource_lock);
918 result = __adjust_resource(res, start, size);
919 write_unlock(&resource_lock);
922 EXPORT_SYMBOL(adjust_resource);
924 static void __init __reserve_region_with_split(struct resource *root,
925 resource_size_t start, resource_size_t end,
928 struct resource *parent = root;
929 struct resource *conflict;
930 struct resource *res = alloc_resource(GFP_ATOMIC);
931 struct resource *next_res = NULL;
939 res->flags = IORESOURCE_BUSY;
943 conflict = __request_resource(parent, res);
952 /* conflict covered whole area */
953 if (conflict->start <= res->start &&
954 conflict->end >= res->end) {
960 /* failed, split and try again */
961 if (conflict->start > res->start) {
963 res->end = conflict->start - 1;
964 if (conflict->end < end) {
965 next_res = alloc_resource(GFP_ATOMIC);
970 next_res->name = name;
971 next_res->start = conflict->end + 1;
973 next_res->flags = IORESOURCE_BUSY;
976 res->start = conflict->end + 1;
982 void __init reserve_region_with_split(struct resource *root,
983 resource_size_t start, resource_size_t end,
988 write_lock(&resource_lock);
989 if (root->start > start || root->end < end) {
990 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
991 (unsigned long long)start, (unsigned long long)end,
993 if (start > root->end || end < root->start)
998 if (start < root->start)
1000 pr_err("fixing request to [0x%llx-0x%llx]\n",
1001 (unsigned long long)start,
1002 (unsigned long long)end);
1007 __reserve_region_with_split(root, start, end, name);
1008 write_unlock(&resource_lock);
1012 * resource_alignment - calculate resource's alignment
1013 * @res: resource pointer
1015 * Returns alignment on success, 0 (invalid alignment) on failure.
1017 resource_size_t resource_alignment(struct resource *res)
1019 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1020 case IORESOURCE_SIZEALIGN:
1021 return resource_size(res);
1022 case IORESOURCE_STARTALIGN:
1030 * This is compatibility stuff for IO resources.
1032 * Note how this, unlike the above, knows about
1033 * the IO flag meanings (busy etc).
1035 * request_region creates a new busy region.
1037 * release_region releases a matching busy region.
1040 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1043 * __request_region - create a new busy resource region
1044 * @parent: parent resource descriptor
1045 * @start: resource start address
1046 * @n: resource region size
1047 * @name: reserving caller's ID string
1048 * @flags: IO resource flags
1050 struct resource * __request_region(struct resource *parent,
1051 resource_size_t start, resource_size_t n,
1052 const char *name, int flags)
1054 DECLARE_WAITQUEUE(wait, current);
1055 struct resource *res = alloc_resource(GFP_KERNEL);
1062 res->end = start + n - 1;
1063 res->flags = resource_type(parent);
1064 res->flags |= IORESOURCE_BUSY | flags;
1066 write_lock(&resource_lock);
1069 struct resource *conflict;
1071 conflict = __request_resource(parent, res);
1074 if (conflict != parent) {
1076 if (!(conflict->flags & IORESOURCE_BUSY))
1079 if (conflict->flags & flags & IORESOURCE_MUXED) {
1080 add_wait_queue(&muxed_resource_wait, &wait);
1081 write_unlock(&resource_lock);
1082 set_current_state(TASK_UNINTERRUPTIBLE);
1084 remove_wait_queue(&muxed_resource_wait, &wait);
1085 write_lock(&resource_lock);
1088 /* Uhhuh, that didn't work out.. */
1093 write_unlock(&resource_lock);
1096 EXPORT_SYMBOL(__request_region);
1099 * __release_region - release a previously reserved resource region
1100 * @parent: parent resource descriptor
1101 * @start: resource start address
1102 * @n: resource region size
1104 * The described resource region must match a currently busy region.
1106 void __release_region(struct resource *parent, resource_size_t start,
1109 struct resource **p;
1110 resource_size_t end;
1113 end = start + n - 1;
1115 write_lock(&resource_lock);
1118 struct resource *res = *p;
1122 if (res->start <= start && res->end >= end) {
1123 if (!(res->flags & IORESOURCE_BUSY)) {
1127 if (res->start != start || res->end != end)
1130 write_unlock(&resource_lock);
1131 if (res->flags & IORESOURCE_MUXED)
1132 wake_up(&muxed_resource_wait);
1139 write_unlock(&resource_lock);
1141 printk(KERN_WARNING "Trying to free nonexistent resource "
1142 "<%016llx-%016llx>\n", (unsigned long long)start,
1143 (unsigned long long)end);
1145 EXPORT_SYMBOL(__release_region);
1147 #ifdef CONFIG_MEMORY_HOTREMOVE
1149 * release_mem_region_adjustable - release a previously reserved memory region
1150 * @parent: parent resource descriptor
1151 * @start: resource start address
1152 * @size: resource region size
1154 * This interface is intended for memory hot-delete. The requested region
1155 * is released from a currently busy memory resource. The requested region
1156 * must either match exactly or fit into a single busy resource entry. In
1157 * the latter case, the remaining resource is adjusted accordingly.
1158 * Existing children of the busy memory resource must be immutable in the
1162 * - Additional release conditions, such as overlapping region, can be
1163 * supported after they are confirmed as valid cases.
1164 * - When a busy memory resource gets split into two entries, the code
1165 * assumes that all children remain in the lower address entry for
1166 * simplicity. Enhance this logic when necessary.
1168 int release_mem_region_adjustable(struct resource *parent,
1169 resource_size_t start, resource_size_t size)
1171 struct resource **p;
1172 struct resource *res;
1173 struct resource *new_res;
1174 resource_size_t end;
1177 end = start + size - 1;
1178 if ((start < parent->start) || (end > parent->end))
1181 /* The alloc_resource() result gets checked later */
1182 new_res = alloc_resource(GFP_KERNEL);
1185 write_lock(&resource_lock);
1187 while ((res = *p)) {
1188 if (res->start >= end)
1191 /* look for the next resource if it does not fit into */
1192 if (res->start > start || res->end < end) {
1197 if (!(res->flags & IORESOURCE_MEM))
1200 if (!(res->flags & IORESOURCE_BUSY)) {
1205 /* found the target resource; let's adjust accordingly */
1206 if (res->start == start && res->end == end) {
1207 /* free the whole entry */
1211 } else if (res->start == start && res->end != end) {
1212 /* adjust the start */
1213 ret = __adjust_resource(res, end + 1,
1215 } else if (res->start != start && res->end == end) {
1216 /* adjust the end */
1217 ret = __adjust_resource(res, res->start,
1218 start - res->start);
1220 /* split into two entries */
1225 new_res->name = res->name;
1226 new_res->start = end + 1;
1227 new_res->end = res->end;
1228 new_res->flags = res->flags;
1229 new_res->parent = res->parent;
1230 new_res->sibling = res->sibling;
1231 new_res->child = NULL;
1233 ret = __adjust_resource(res, res->start,
1234 start - res->start);
1237 res->sibling = new_res;
1244 write_unlock(&resource_lock);
1245 free_resource(new_res);
1248 #endif /* CONFIG_MEMORY_HOTREMOVE */
1251 * Managed region resource
1253 static void devm_resource_release(struct device *dev, void *ptr)
1255 struct resource **r = ptr;
1257 release_resource(*r);
1261 * devm_request_resource() - request and reserve an I/O or memory resource
1262 * @dev: device for which to request the resource
1263 * @root: root of the resource tree from which to request the resource
1264 * @new: descriptor of the resource to request
1266 * This is a device-managed version of request_resource(). There is usually
1267 * no need to release resources requested by this function explicitly since
1268 * that will be taken care of when the device is unbound from its driver.
1269 * If for some reason the resource needs to be released explicitly, because
1270 * of ordering issues for example, drivers must call devm_release_resource()
1271 * rather than the regular release_resource().
1273 * When a conflict is detected between any existing resources and the newly
1274 * requested resource, an error message will be printed.
1276 * Returns 0 on success or a negative error code on failure.
1278 int devm_request_resource(struct device *dev, struct resource *root,
1279 struct resource *new)
1281 struct resource *conflict, **ptr;
1283 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1289 conflict = request_resource_conflict(root, new);
1291 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1292 new, conflict->name, conflict);
1297 devres_add(dev, ptr);
1300 EXPORT_SYMBOL(devm_request_resource);
1302 static int devm_resource_match(struct device *dev, void *res, void *data)
1304 struct resource **ptr = res;
1306 return *ptr == data;
1310 * devm_release_resource() - release a previously requested resource
1311 * @dev: device for which to release the resource
1312 * @new: descriptor of the resource to release
1314 * Releases a resource previously requested using devm_request_resource().
1316 void devm_release_resource(struct device *dev, struct resource *new)
1318 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1321 EXPORT_SYMBOL(devm_release_resource);
1323 struct region_devres {
1324 struct resource *parent;
1325 resource_size_t start;
1329 static void devm_region_release(struct device *dev, void *res)
1331 struct region_devres *this = res;
1333 __release_region(this->parent, this->start, this->n);
1336 static int devm_region_match(struct device *dev, void *res, void *match_data)
1338 struct region_devres *this = res, *match = match_data;
1340 return this->parent == match->parent &&
1341 this->start == match->start && this->n == match->n;
1344 struct resource * __devm_request_region(struct device *dev,
1345 struct resource *parent, resource_size_t start,
1346 resource_size_t n, const char *name)
1348 struct region_devres *dr = NULL;
1349 struct resource *res;
1351 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1356 dr->parent = parent;
1360 res = __request_region(parent, start, n, name, 0);
1362 devres_add(dev, dr);
1368 EXPORT_SYMBOL(__devm_request_region);
1370 void __devm_release_region(struct device *dev, struct resource *parent,
1371 resource_size_t start, resource_size_t n)
1373 struct region_devres match_data = { parent, start, n };
1375 __release_region(parent, start, n);
1376 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1379 EXPORT_SYMBOL(__devm_release_region);
1382 * Called from init/main.c to reserve IO ports.
1384 #define MAXRESERVE 4
1385 static int __init reserve_setup(char *str)
1387 static int reserved;
1388 static struct resource reserve[MAXRESERVE];
1391 unsigned int io_start, io_num;
1394 if (get_option (&str, &io_start) != 2)
1396 if (get_option (&str, &io_num) == 0)
1398 if (x < MAXRESERVE) {
1399 struct resource *res = reserve + x;
1400 res->name = "reserved";
1401 res->start = io_start;
1402 res->end = io_start + io_num - 1;
1403 res->flags = IORESOURCE_BUSY;
1405 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1412 __setup("reserve=", reserve_setup);
1415 * Check if the requested addr and size spans more than any slot in the
1416 * iomem resource tree.
1418 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1420 struct resource *p = &iomem_resource;
1424 read_lock(&resource_lock);
1425 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1427 * We can probably skip the resources without
1428 * IORESOURCE_IO attribute?
1430 if (p->start >= addr + size)
1434 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1435 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1438 * if a resource is "BUSY", it's not a hardware resource
1439 * but a driver mapping of such a resource; we don't want
1440 * to warn for those; some drivers legitimately map only
1441 * partial hardware resources. (example: vesafb)
1443 if (p->flags & IORESOURCE_BUSY)
1446 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1447 (unsigned long long)addr,
1448 (unsigned long long)(addr + size - 1),
1453 read_unlock(&resource_lock);
1458 #ifdef CONFIG_STRICT_DEVMEM
1459 static int strict_iomem_checks = 1;
1461 static int strict_iomem_checks;
1465 * check if an address is reserved in the iomem resource tree
1466 * returns 1 if reserved, 0 if not reserved.
1468 int iomem_is_exclusive(u64 addr)
1470 struct resource *p = &iomem_resource;
1473 int size = PAGE_SIZE;
1475 if (!strict_iomem_checks)
1478 addr = addr & PAGE_MASK;
1480 read_lock(&resource_lock);
1481 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1483 * We can probably skip the resources without
1484 * IORESOURCE_IO attribute?
1486 if (p->start >= addr + size)
1490 if (p->flags & IORESOURCE_BUSY &&
1491 p->flags & IORESOURCE_EXCLUSIVE) {
1496 read_unlock(&resource_lock);
1501 struct resource_entry *resource_list_create_entry(struct resource *res,
1504 struct resource_entry *entry;
1506 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1508 INIT_LIST_HEAD(&entry->node);
1509 entry->res = res ? res : &entry->__res;
1514 EXPORT_SYMBOL(resource_list_create_entry);
1516 void resource_list_free(struct list_head *head)
1518 struct resource_entry *entry, *tmp;
1520 list_for_each_entry_safe(entry, tmp, head, node)
1521 resource_list_destroy_entry(entry);
1523 EXPORT_SYMBOL(resource_list_free);
1525 static int __init strict_iomem(char *str)
1527 if (strstr(str, "relaxed"))
1528 strict_iomem_checks = 0;
1529 if (strstr(str, "strict"))
1530 strict_iomem_checks = 1;
1534 __setup("iomem=", strict_iomem);