2 * linux/kernel/resource.c
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
7 * Arbitrary resource management.
10 #include <linux/module.h>
11 #include <linux/errno.h>
12 #include <linux/ioport.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
17 #include <linux/proc_fs.h>
18 #include <linux/sched.h>
19 #include <linux/seq_file.h>
20 #include <linux/device.h>
21 #include <linux/pfn.h>
25 struct resource ioport_resource = {
28 .end = IO_SPACE_LIMIT,
29 .flags = IORESOURCE_IO,
31 EXPORT_SYMBOL(ioport_resource);
33 struct resource iomem_resource = {
37 .flags = IORESOURCE_MEM,
39 EXPORT_SYMBOL(iomem_resource);
41 static DEFINE_RWLOCK(resource_lock);
43 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
45 struct resource *p = v;
49 while (!p->sibling && p->parent)
56 enum { MAX_IORES_LEVEL = 5 };
58 static void *r_start(struct seq_file *m, loff_t *pos)
59 __acquires(resource_lock)
61 struct resource *p = m->private;
63 read_lock(&resource_lock);
64 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
69 static void r_stop(struct seq_file *m, void *v)
70 __releases(resource_lock)
72 read_unlock(&resource_lock);
75 static int r_show(struct seq_file *m, void *v)
77 struct resource *root = m->private;
78 struct resource *r = v, *p;
79 int width = root->end < 0x10000 ? 4 : 8;
82 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
83 if (p->parent == root)
85 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
87 width, (unsigned long long) r->start,
88 width, (unsigned long long) r->end,
89 r->name ? r->name : "<BAD>");
93 static const struct seq_operations resource_op = {
100 static int ioports_open(struct inode *inode, struct file *file)
102 int res = seq_open(file, &resource_op);
104 struct seq_file *m = file->private_data;
105 m->private = &ioport_resource;
110 static int iomem_open(struct inode *inode, struct file *file)
112 int res = seq_open(file, &resource_op);
114 struct seq_file *m = file->private_data;
115 m->private = &iomem_resource;
120 static const struct file_operations proc_ioports_operations = {
121 .open = ioports_open,
124 .release = seq_release,
127 static const struct file_operations proc_iomem_operations = {
131 .release = seq_release,
134 static int __init ioresources_init(void)
136 proc_create("ioports", 0, NULL, &proc_ioports_operations);
137 proc_create("iomem", 0, NULL, &proc_iomem_operations);
140 __initcall(ioresources_init);
142 #endif /* CONFIG_PROC_FS */
144 /* Return the conflict entry if you can't request it */
145 static struct resource * __request_resource(struct resource *root, struct resource *new)
147 resource_size_t start = new->start;
148 resource_size_t end = new->end;
149 struct resource *tmp, **p;
153 if (start < root->start)
160 if (!tmp || tmp->start > end) {
167 if (tmp->end < start)
173 static int __release_resource(struct resource *old)
175 struct resource *tmp, **p;
177 p = &old->parent->child;
192 static void __release_child_resources(struct resource *r)
194 struct resource *tmp, *p;
195 resource_size_t size;
205 __release_child_resources(tmp);
207 printk(KERN_DEBUG "release child resource %pR\n", tmp);
208 /* need to restore size, and keep flags */
209 size = resource_size(tmp);
215 void release_child_resources(struct resource *r)
217 write_lock(&resource_lock);
218 __release_child_resources(r);
219 write_unlock(&resource_lock);
223 * request_resource_conflict - request and reserve an I/O or memory resource
224 * @root: root resource descriptor
225 * @new: resource descriptor desired by caller
227 * Returns 0 for success, conflict resource on error.
229 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
231 struct resource *conflict;
233 write_lock(&resource_lock);
234 conflict = __request_resource(root, new);
235 write_unlock(&resource_lock);
240 * request_resource - request and reserve an I/O or memory resource
241 * @root: root resource descriptor
242 * @new: resource descriptor desired by caller
244 * Returns 0 for success, negative error code on error.
246 int request_resource(struct resource *root, struct resource *new)
248 struct resource *conflict;
250 conflict = request_resource_conflict(root, new);
251 return conflict ? -EBUSY : 0;
254 EXPORT_SYMBOL(request_resource);
257 * release_resource - release a previously reserved resource
258 * @old: resource pointer
260 int release_resource(struct resource *old)
264 write_lock(&resource_lock);
265 retval = __release_resource(old);
266 write_unlock(&resource_lock);
270 EXPORT_SYMBOL(release_resource);
272 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
274 * Finds the lowest memory reosurce exists within [res->start.res->end)
275 * the caller must specify res->start, res->end, res->flags and "name".
276 * If found, returns 0, res is overwritten, if not found, returns -1.
278 static int find_next_system_ram(struct resource *res, char *name)
280 resource_size_t start, end;
287 BUG_ON(start >= end);
289 read_lock(&resource_lock);
290 for (p = iomem_resource.child; p ; p = p->sibling) {
291 /* system ram is just marked as IORESOURCE_MEM */
292 if (p->flags != res->flags)
294 if (name && strcmp(p->name, name))
296 if (p->start > end) {
300 if ((p->end >= start) && (p->start < end))
303 read_unlock(&resource_lock);
307 if (res->start < p->start)
308 res->start = p->start;
309 if (res->end > p->end)
315 * This function calls callback against all memory range of "System RAM"
316 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
317 * Now, this function is only for "System RAM".
319 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
320 void *arg, int (*func)(unsigned long, unsigned long, void *))
323 unsigned long pfn, end_pfn;
327 res.start = (u64) start_pfn << PAGE_SHIFT;
328 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
329 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
331 while ((res.start < res.end) &&
332 (find_next_system_ram(&res, "System RAM") >= 0)) {
333 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
334 end_pfn = (res.end + 1) >> PAGE_SHIFT;
336 ret = (*func)(pfn, end_pfn - pfn, arg);
339 res.start = res.end + 1;
347 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
352 * This generic page_is_ram() returns true if specified address is
353 * registered as "System RAM" in iomem_resource list.
355 int __weak page_is_ram(unsigned long pfn)
357 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
361 * Find empty slot in the resource tree given range and alignment.
363 static int find_resource(struct resource *root, struct resource *new,
364 resource_size_t size, resource_size_t min,
365 resource_size_t max, resource_size_t align,
366 resource_size_t (*alignf)(void *,
367 const struct resource *,
372 struct resource *this = root->child;
373 struct resource tmp = *new;
375 tmp.start = root->start;
377 * Skip past an allocated resource that starts at 0, since the assignment
378 * of this->start - 1 to tmp->end below would cause an underflow.
380 if (this && this->start == 0) {
381 tmp.start = this->end + 1;
382 this = this->sibling;
386 tmp.end = this->start - 1;
393 tmp.start = ALIGN(tmp.start, align);
395 tmp.start = alignf(alignf_data, &tmp, size, align);
396 if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
397 new->start = tmp.start;
398 new->end = tmp.start + size - 1;
403 tmp.start = this->end + 1;
404 this = this->sibling;
410 * allocate_resource - allocate empty slot in the resource tree given range & alignment
411 * @root: root resource descriptor
412 * @new: resource descriptor desired by caller
413 * @size: requested resource region size
414 * @min: minimum size to allocate
415 * @max: maximum size to allocate
416 * @align: alignment requested, in bytes
417 * @alignf: alignment function, optional, called if not NULL
418 * @alignf_data: arbitrary data to pass to the @alignf function
420 int allocate_resource(struct resource *root, struct resource *new,
421 resource_size_t size, resource_size_t min,
422 resource_size_t max, resource_size_t align,
423 resource_size_t (*alignf)(void *,
424 const struct resource *,
431 write_lock(&resource_lock);
432 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
433 if (err >= 0 && __request_resource(root, new))
435 write_unlock(&resource_lock);
439 EXPORT_SYMBOL(allocate_resource);
442 * Insert a resource into the resource tree. If successful, return NULL,
443 * otherwise return the conflicting resource (compare to __request_resource())
445 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
447 struct resource *first, *next;
449 for (;; parent = first) {
450 first = __request_resource(parent, new);
457 if ((first->start > new->start) || (first->end < new->end))
459 if ((first->start == new->start) && (first->end == new->end))
463 for (next = first; ; next = next->sibling) {
464 /* Partial overlap? Bad, and unfixable */
465 if (next->start < new->start || next->end > new->end)
469 if (next->sibling->start > new->end)
473 new->parent = parent;
474 new->sibling = next->sibling;
477 next->sibling = NULL;
478 for (next = first; next; next = next->sibling)
481 if (parent->child == first) {
484 next = parent->child;
485 while (next->sibling != first)
486 next = next->sibling;
493 * insert_resource_conflict - Inserts resource in the resource tree
494 * @parent: parent of the new resource
495 * @new: new resource to insert
497 * Returns 0 on success, conflict resource if the resource can't be inserted.
499 * This function is equivalent to request_resource_conflict when no conflict
500 * happens. If a conflict happens, and the conflicting resources
501 * entirely fit within the range of the new resource, then the new
502 * resource is inserted and the conflicting resources become children of
505 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
507 struct resource *conflict;
509 write_lock(&resource_lock);
510 conflict = __insert_resource(parent, new);
511 write_unlock(&resource_lock);
516 * insert_resource - Inserts a resource in the resource tree
517 * @parent: parent of the new resource
518 * @new: new resource to insert
520 * Returns 0 on success, -EBUSY if the resource can't be inserted.
522 int insert_resource(struct resource *parent, struct resource *new)
524 struct resource *conflict;
526 conflict = insert_resource_conflict(parent, new);
527 return conflict ? -EBUSY : 0;
531 * insert_resource_expand_to_fit - Insert a resource into the resource tree
532 * @root: root resource descriptor
533 * @new: new resource to insert
535 * Insert a resource into the resource tree, possibly expanding it in order
536 * to make it encompass any conflicting resources.
538 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
543 write_lock(&resource_lock);
545 struct resource *conflict;
547 conflict = __insert_resource(root, new);
550 if (conflict == root)
553 /* Ok, expand resource to cover the conflict, then try again .. */
554 if (conflict->start < new->start)
555 new->start = conflict->start;
556 if (conflict->end > new->end)
557 new->end = conflict->end;
559 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
561 write_unlock(&resource_lock);
565 * adjust_resource - modify a resource's start and size
566 * @res: resource to modify
567 * @start: new start value
570 * Given an existing resource, change its start and size to match the
571 * arguments. Returns 0 on success, -EBUSY if it can't fit.
572 * Existing children of the resource are assumed to be immutable.
574 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
576 struct resource *tmp, *parent = res->parent;
577 resource_size_t end = start + size - 1;
580 write_lock(&resource_lock);
582 if ((start < parent->start) || (end > parent->end))
585 for (tmp = res->child; tmp; tmp = tmp->sibling) {
586 if ((tmp->start < start) || (tmp->end > end))
590 if (res->sibling && (res->sibling->start <= end))
595 while (tmp->sibling != res)
597 if (start <= tmp->end)
606 write_unlock(&resource_lock);
610 static void __init __reserve_region_with_split(struct resource *root,
611 resource_size_t start, resource_size_t end,
614 struct resource *parent = root;
615 struct resource *conflict;
616 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
624 res->flags = IORESOURCE_BUSY;
626 conflict = __request_resource(parent, res);
630 /* failed, split and try again */
633 /* conflict covered whole area */
634 if (conflict->start <= start && conflict->end >= end)
637 if (conflict->start > start)
638 __reserve_region_with_split(root, start, conflict->start-1, name);
639 if (conflict->end < end)
640 __reserve_region_with_split(root, conflict->end+1, end, name);
643 void __init reserve_region_with_split(struct resource *root,
644 resource_size_t start, resource_size_t end,
647 write_lock(&resource_lock);
648 __reserve_region_with_split(root, start, end, name);
649 write_unlock(&resource_lock);
652 EXPORT_SYMBOL(adjust_resource);
655 * resource_alignment - calculate resource's alignment
656 * @res: resource pointer
658 * Returns alignment on success, 0 (invalid alignment) on failure.
660 resource_size_t resource_alignment(struct resource *res)
662 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
663 case IORESOURCE_SIZEALIGN:
664 return resource_size(res);
665 case IORESOURCE_STARTALIGN:
673 * This is compatibility stuff for IO resources.
675 * Note how this, unlike the above, knows about
676 * the IO flag meanings (busy etc).
678 * request_region creates a new busy region.
680 * check_region returns non-zero if the area is already busy.
682 * release_region releases a matching busy region.
685 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
688 * __request_region - create a new busy resource region
689 * @parent: parent resource descriptor
690 * @start: resource start address
691 * @n: resource region size
692 * @name: reserving caller's ID string
693 * @flags: IO resource flags
695 struct resource * __request_region(struct resource *parent,
696 resource_size_t start, resource_size_t n,
697 const char *name, int flags)
699 DECLARE_WAITQUEUE(wait, current);
700 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
707 res->end = start + n - 1;
708 res->flags = IORESOURCE_BUSY;
711 write_lock(&resource_lock);
714 struct resource *conflict;
716 conflict = __request_resource(parent, res);
719 if (conflict != parent) {
721 if (!(conflict->flags & IORESOURCE_BUSY))
724 if (conflict->flags & flags & IORESOURCE_MUXED) {
725 add_wait_queue(&muxed_resource_wait, &wait);
726 write_unlock(&resource_lock);
727 set_current_state(TASK_UNINTERRUPTIBLE);
729 remove_wait_queue(&muxed_resource_wait, &wait);
730 write_lock(&resource_lock);
733 /* Uhhuh, that didn't work out.. */
738 write_unlock(&resource_lock);
741 EXPORT_SYMBOL(__request_region);
744 * __check_region - check if a resource region is busy or free
745 * @parent: parent resource descriptor
746 * @start: resource start address
747 * @n: resource region size
749 * Returns 0 if the region is free at the moment it is checked,
750 * returns %-EBUSY if the region is busy.
753 * This function is deprecated because its use is racy.
754 * Even if it returns 0, a subsequent call to request_region()
755 * may fail because another driver etc. just allocated the region.
756 * Do NOT use it. It will be removed from the kernel.
758 int __check_region(struct resource *parent, resource_size_t start,
761 struct resource * res;
763 res = __request_region(parent, start, n, "check-region", 0);
767 release_resource(res);
771 EXPORT_SYMBOL(__check_region);
774 * __release_region - release a previously reserved resource region
775 * @parent: parent resource descriptor
776 * @start: resource start address
777 * @n: resource region size
779 * The described resource region must match a currently busy region.
781 void __release_region(struct resource *parent, resource_size_t start,
790 write_lock(&resource_lock);
793 struct resource *res = *p;
797 if (res->start <= start && res->end >= end) {
798 if (!(res->flags & IORESOURCE_BUSY)) {
802 if (res->start != start || res->end != end)
805 write_unlock(&resource_lock);
806 if (res->flags & IORESOURCE_MUXED)
807 wake_up(&muxed_resource_wait);
814 write_unlock(&resource_lock);
816 printk(KERN_WARNING "Trying to free nonexistent resource "
817 "<%016llx-%016llx>\n", (unsigned long long)start,
818 (unsigned long long)end);
820 EXPORT_SYMBOL(__release_region);
823 * Managed region resource
825 struct region_devres {
826 struct resource *parent;
827 resource_size_t start;
831 static void devm_region_release(struct device *dev, void *res)
833 struct region_devres *this = res;
835 __release_region(this->parent, this->start, this->n);
838 static int devm_region_match(struct device *dev, void *res, void *match_data)
840 struct region_devres *this = res, *match = match_data;
842 return this->parent == match->parent &&
843 this->start == match->start && this->n == match->n;
846 struct resource * __devm_request_region(struct device *dev,
847 struct resource *parent, resource_size_t start,
848 resource_size_t n, const char *name)
850 struct region_devres *dr = NULL;
851 struct resource *res;
853 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
862 res = __request_region(parent, start, n, name, 0);
870 EXPORT_SYMBOL(__devm_request_region);
872 void __devm_release_region(struct device *dev, struct resource *parent,
873 resource_size_t start, resource_size_t n)
875 struct region_devres match_data = { parent, start, n };
877 __release_region(parent, start, n);
878 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
881 EXPORT_SYMBOL(__devm_release_region);
884 * Called from init/main.c to reserve IO ports.
887 static int __init reserve_setup(char *str)
890 static struct resource reserve[MAXRESERVE];
893 unsigned int io_start, io_num;
896 if (get_option (&str, &io_start) != 2)
898 if (get_option (&str, &io_num) == 0)
900 if (x < MAXRESERVE) {
901 struct resource *res = reserve + x;
902 res->name = "reserved";
903 res->start = io_start;
904 res->end = io_start + io_num - 1;
905 res->flags = IORESOURCE_BUSY;
907 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
914 __setup("reserve=", reserve_setup);
917 * Check if the requested addr and size spans more than any slot in the
918 * iomem resource tree.
920 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
922 struct resource *p = &iomem_resource;
926 read_lock(&resource_lock);
927 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
929 * We can probably skip the resources without
930 * IORESOURCE_IO attribute?
932 if (p->start >= addr + size)
936 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
937 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
940 * if a resource is "BUSY", it's not a hardware resource
941 * but a driver mapping of such a resource; we don't want
942 * to warn for those; some drivers legitimately map only
943 * partial hardware resources. (example: vesafb)
945 if (p->flags & IORESOURCE_BUSY)
948 printk(KERN_WARNING "resource map sanity check conflict: "
949 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
950 (unsigned long long)addr,
951 (unsigned long long)(addr + size - 1),
952 (unsigned long long)p->start,
953 (unsigned long long)p->end,
958 read_unlock(&resource_lock);
963 #ifdef CONFIG_STRICT_DEVMEM
964 static int strict_iomem_checks = 1;
966 static int strict_iomem_checks;
970 * check if an address is reserved in the iomem resource tree
971 * returns 1 if reserved, 0 if not reserved.
973 int iomem_is_exclusive(u64 addr)
975 struct resource *p = &iomem_resource;
978 int size = PAGE_SIZE;
980 if (!strict_iomem_checks)
983 addr = addr & PAGE_MASK;
985 read_lock(&resource_lock);
986 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
988 * We can probably skip the resources without
989 * IORESOURCE_IO attribute?
991 if (p->start >= addr + size)
995 if (p->flags & IORESOURCE_BUSY &&
996 p->flags & IORESOURCE_EXCLUSIVE) {
1001 read_unlock(&resource_lock);
1006 static int __init strict_iomem(char *str)
1008 if (strstr(str, "relaxed"))
1009 strict_iomem_checks = 0;
1010 if (strstr(str, "strict"))
1011 strict_iomem_checks = 1;
1015 __setup("iomem=", strict_iomem);