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/config.h>
11 #include <linux/module.h>
12 #include <linux/sched.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/seq_file.h>
24 struct resource ioport_resource = {
27 .end = IO_SPACE_LIMIT,
28 .flags = IORESOURCE_IO,
30 EXPORT_SYMBOL(ioport_resource);
32 struct resource iomem_resource = {
36 .flags = IORESOURCE_MEM,
38 EXPORT_SYMBOL(iomem_resource);
40 static DEFINE_RWLOCK(resource_lock);
44 enum { MAX_IORES_LEVEL = 5 };
46 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
48 struct resource *p = v;
52 while (!p->sibling && p->parent)
57 static void *r_start(struct seq_file *m, loff_t *pos)
58 __acquires(resource_lock)
60 struct resource *p = m->private;
62 read_lock(&resource_lock);
63 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
68 static void r_stop(struct seq_file *m, void *v)
69 __releases(resource_lock)
71 read_unlock(&resource_lock);
74 static int r_show(struct seq_file *m, void *v)
76 struct resource *root = m->private;
77 struct resource *r = v, *p;
78 int width = root->end < 0x10000 ? 4 : 8;
81 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
82 if (p->parent == root)
84 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
86 width, (unsigned long long) r->start,
87 width, (unsigned long long) r->end,
88 r->name ? r->name : "<BAD>");
92 static struct seq_operations resource_op = {
99 static int ioports_open(struct inode *inode, struct file *file)
101 int res = seq_open(file, &resource_op);
103 struct seq_file *m = file->private_data;
104 m->private = &ioport_resource;
109 static int iomem_open(struct inode *inode, struct file *file)
111 int res = seq_open(file, &resource_op);
113 struct seq_file *m = file->private_data;
114 m->private = &iomem_resource;
119 static struct file_operations proc_ioports_operations = {
120 .open = ioports_open,
123 .release = seq_release,
126 static struct file_operations proc_iomem_operations = {
130 .release = seq_release,
133 static int __init ioresources_init(void)
135 struct proc_dir_entry *entry;
137 entry = create_proc_entry("ioports", 0, NULL);
139 entry->proc_fops = &proc_ioports_operations;
140 entry = create_proc_entry("iomem", 0, NULL);
142 entry->proc_fops = &proc_iomem_operations;
145 __initcall(ioresources_init);
147 #endif /* CONFIG_PROC_FS */
149 /* Return the conflict entry if you can't request it */
150 static struct resource * __request_resource(struct resource *root, struct resource *new)
152 resource_size_t start = new->start;
153 resource_size_t end = new->end;
154 struct resource *tmp, **p;
158 if (start < root->start)
165 if (!tmp || tmp->start > end) {
172 if (tmp->end < start)
178 static int __release_resource(struct resource *old)
180 struct resource *tmp, **p;
182 p = &old->parent->child;
197 int request_resource(struct resource *root, struct resource *new)
199 struct resource *conflict;
201 write_lock(&resource_lock);
202 conflict = __request_resource(root, new);
203 write_unlock(&resource_lock);
204 return conflict ? -EBUSY : 0;
207 EXPORT_SYMBOL(request_resource);
209 struct resource *____request_resource(struct resource *root, struct resource *new)
211 struct resource *conflict;
213 write_lock(&resource_lock);
214 conflict = __request_resource(root, new);
215 write_unlock(&resource_lock);
219 EXPORT_SYMBOL(____request_resource);
221 int release_resource(struct resource *old)
225 write_lock(&resource_lock);
226 retval = __release_resource(old);
227 write_unlock(&resource_lock);
231 EXPORT_SYMBOL(release_resource);
233 #ifdef CONFIG_MEMORY_HOTPLUG
235 * Finds the lowest memory reosurce exists within [res->start.res->end)
236 * the caller must specify res->start, res->end, res->flags.
237 * If found, returns 0, res is overwritten, if not found, returns -1.
239 int find_next_system_ram(struct resource *res)
241 resource_size_t start, end;
249 read_lock(&resource_lock);
250 for (p = iomem_resource.child; p ; p = p->sibling) {
251 /* system ram is just marked as IORESOURCE_MEM */
252 if (p->flags != res->flags)
254 if (p->start > end) {
258 if (p->start >= start)
261 read_unlock(&resource_lock);
265 res->start = p->start;
272 * Find empty slot in the resource tree given range and alignment.
274 static int find_resource(struct resource *root, struct resource *new,
275 resource_size_t size, resource_size_t min,
276 resource_size_t max, resource_size_t align,
277 void (*alignf)(void *, struct resource *,
278 resource_size_t, resource_size_t),
281 struct resource *this = root->child;
283 new->start = root->start;
285 * Skip past an allocated resource that starts at 0, since the assignment
286 * of this->start - 1 to new->end below would cause an underflow.
288 if (this && this->start == 0) {
289 new->start = this->end + 1;
290 this = this->sibling;
294 new->end = this->start - 1;
296 new->end = root->end;
297 if (new->start < min)
301 new->start = ALIGN(new->start, align);
303 alignf(alignf_data, new, size, align);
304 if (new->start < new->end && new->end - new->start >= size - 1) {
305 new->end = new->start + size - 1;
310 new->start = this->end + 1;
311 this = this->sibling;
317 * Allocate empty slot in the resource tree given range and alignment.
319 int allocate_resource(struct resource *root, struct resource *new,
320 resource_size_t size, resource_size_t min,
321 resource_size_t max, resource_size_t align,
322 void (*alignf)(void *, struct resource *,
323 resource_size_t, resource_size_t),
328 write_lock(&resource_lock);
329 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
330 if (err >= 0 && __request_resource(root, new))
332 write_unlock(&resource_lock);
336 EXPORT_SYMBOL(allocate_resource);
339 * insert_resource - Inserts a resource in the resource tree
340 * @parent: parent of the new resource
341 * @new: new resource to insert
343 * Returns 0 on success, -EBUSY if the resource can't be inserted.
345 * This function is equivalent of request_resource when no conflict
346 * happens. If a conflict happens, and the conflicting resources
347 * entirely fit within the range of the new resource, then the new
348 * resource is inserted and the conflicting resources become childs of
349 * the new resource. Otherwise the new resource becomes the child of
350 * the conflicting resource
352 int insert_resource(struct resource *parent, struct resource *new)
355 struct resource *first, *next;
357 write_lock(&resource_lock);
360 first = __request_resource(parent, new);
368 /* Resource fully contained by the clashing resource? Recurse into it */
369 if (first->start <= new->start && first->end >= new->end) {
374 for (next = first; ; next = next->sibling) {
375 /* Partial overlap? Bad, and unfixable */
376 if (next->start < new->start || next->end > new->end)
380 if (next->sibling->start > new->end)
386 new->parent = parent;
387 new->sibling = next->sibling;
390 next->sibling = NULL;
391 for (next = first; next; next = next->sibling)
394 if (parent->child == first) {
397 next = parent->child;
398 while (next->sibling != first)
399 next = next->sibling;
404 write_unlock(&resource_lock);
408 EXPORT_SYMBOL(insert_resource);
411 * Given an existing resource, change its start and size to match the
412 * arguments. Returns -EBUSY if it can't fit. Existing children of
413 * the resource are assumed to be immutable.
415 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
417 struct resource *tmp, *parent = res->parent;
418 resource_size_t end = start + size - 1;
421 write_lock(&resource_lock);
423 if ((start < parent->start) || (end > parent->end))
426 for (tmp = res->child; tmp; tmp = tmp->sibling) {
427 if ((tmp->start < start) || (tmp->end > end))
431 if (res->sibling && (res->sibling->start <= end))
436 while (tmp->sibling != res)
438 if (start <= tmp->end)
447 write_unlock(&resource_lock);
451 EXPORT_SYMBOL(adjust_resource);
454 * This is compatibility stuff for IO resources.
456 * Note how this, unlike the above, knows about
457 * the IO flag meanings (busy etc).
459 * Request-region creates a new busy region.
461 * Check-region returns non-zero if the area is already busy
463 * Release-region releases a matching busy region.
465 struct resource * __request_region(struct resource *parent,
466 resource_size_t start, resource_size_t n,
469 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
474 res->end = start + n - 1;
475 res->flags = IORESOURCE_BUSY;
477 write_lock(&resource_lock);
480 struct resource *conflict;
482 conflict = __request_resource(parent, res);
485 if (conflict != parent) {
487 if (!(conflict->flags & IORESOURCE_BUSY))
491 /* Uhhuh, that didn't work out.. */
496 write_unlock(&resource_lock);
501 EXPORT_SYMBOL(__request_region);
503 int __check_region(struct resource *parent, resource_size_t start,
506 struct resource * res;
508 res = __request_region(parent, start, n, "check-region");
512 release_resource(res);
517 EXPORT_SYMBOL(__check_region);
519 void __release_region(struct resource *parent, resource_size_t start,
528 write_lock(&resource_lock);
531 struct resource *res = *p;
535 if (res->start <= start && res->end >= end) {
536 if (!(res->flags & IORESOURCE_BUSY)) {
540 if (res->start != start || res->end != end)
543 write_unlock(&resource_lock);
550 write_unlock(&resource_lock);
552 printk(KERN_WARNING "Trying to free nonexistent resource "
553 "<%016llx-%016llx>\n", (unsigned long long)start,
554 (unsigned long long)end);
557 EXPORT_SYMBOL(__release_region);
560 * Called from init/main.c to reserve IO ports.
563 static int __init reserve_setup(char *str)
566 static struct resource reserve[MAXRESERVE];
569 int io_start, io_num;
572 if (get_option (&str, &io_start) != 2)
574 if (get_option (&str, &io_num) == 0)
576 if (x < MAXRESERVE) {
577 struct resource *res = reserve + x;
578 res->name = "reserved";
579 res->start = io_start;
580 res->end = io_start + io_num - 1;
581 res->flags = IORESOURCE_BUSY;
583 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
590 __setup("reserve=", reserve_setup);