sound: oxygen: allow custom MCLK rates
[firewire-audio.git] / kernel / resource.c
blobfb11a58b95948a08c57ec46033f538d974a480dd
1 /*
2 * linux/kernel/resource.c
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
7 * Arbitrary resource management.
8 */
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>
16 #include <linux/fs.h>
17 #include <linux/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/device.h>
20 #include <linux/pfn.h>
21 #include <asm/io.h>
24 struct resource ioport_resource = {
25 .name = "PCI IO",
26 .start = 0,
27 .end = IO_SPACE_LIMIT,
28 .flags = IORESOURCE_IO,
30 EXPORT_SYMBOL(ioport_resource);
32 struct resource iomem_resource = {
33 .name = "PCI mem",
34 .start = 0,
35 .end = -1,
36 .flags = IORESOURCE_MEM,
38 EXPORT_SYMBOL(iomem_resource);
40 static DEFINE_RWLOCK(resource_lock);
42 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
44 struct resource *p = v;
45 (*pos)++;
46 if (p->child)
47 return p->child;
48 while (!p->sibling && p->parent)
49 p = p->parent;
50 return p->sibling;
53 #ifdef CONFIG_PROC_FS
55 enum { MAX_IORES_LEVEL = 5 };
57 static void *r_start(struct seq_file *m, loff_t *pos)
58 __acquires(resource_lock)
60 struct resource *p = m->private;
61 loff_t l = 0;
62 read_lock(&resource_lock);
63 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
65 return p;
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;
79 int depth;
81 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
82 if (p->parent == root)
83 break;
84 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
85 depth * 2, "",
86 width, (unsigned long long) r->start,
87 width, (unsigned long long) r->end,
88 r->name ? r->name : "<BAD>");
89 return 0;
92 static const struct seq_operations resource_op = {
93 .start = r_start,
94 .next = r_next,
95 .stop = r_stop,
96 .show = r_show,
99 static int ioports_open(struct inode *inode, struct file *file)
101 int res = seq_open(file, &resource_op);
102 if (!res) {
103 struct seq_file *m = file->private_data;
104 m->private = &ioport_resource;
106 return res;
109 static int iomem_open(struct inode *inode, struct file *file)
111 int res = seq_open(file, &resource_op);
112 if (!res) {
113 struct seq_file *m = file->private_data;
114 m->private = &iomem_resource;
116 return res;
119 static const struct file_operations proc_ioports_operations = {
120 .open = ioports_open,
121 .read = seq_read,
122 .llseek = seq_lseek,
123 .release = seq_release,
126 static const struct file_operations proc_iomem_operations = {
127 .open = iomem_open,
128 .read = seq_read,
129 .llseek = seq_lseek,
130 .release = seq_release,
133 static int __init ioresources_init(void)
135 proc_create("ioports", 0, NULL, &proc_ioports_operations);
136 proc_create("iomem", 0, NULL, &proc_iomem_operations);
137 return 0;
139 __initcall(ioresources_init);
141 #endif /* CONFIG_PROC_FS */
143 /* Return the conflict entry if you can't request it */
144 static struct resource * __request_resource(struct resource *root, struct resource *new)
146 resource_size_t start = new->start;
147 resource_size_t end = new->end;
148 struct resource *tmp, **p;
150 if (end < start)
151 return root;
152 if (start < root->start)
153 return root;
154 if (end > root->end)
155 return root;
156 p = &root->child;
157 for (;;) {
158 tmp = *p;
159 if (!tmp || tmp->start > end) {
160 new->sibling = tmp;
161 *p = new;
162 new->parent = root;
163 return NULL;
165 p = &tmp->sibling;
166 if (tmp->end < start)
167 continue;
168 return tmp;
172 static int __release_resource(struct resource *old)
174 struct resource *tmp, **p;
176 p = &old->parent->child;
177 for (;;) {
178 tmp = *p;
179 if (!tmp)
180 break;
181 if (tmp == old) {
182 *p = tmp->sibling;
183 old->parent = NULL;
184 return 0;
186 p = &tmp->sibling;
188 return -EINVAL;
192 * request_resource - request and reserve an I/O or memory resource
193 * @root: root resource descriptor
194 * @new: resource descriptor desired by caller
196 * Returns 0 for success, negative error code on error.
198 int request_resource(struct resource *root, struct resource *new)
200 struct resource *conflict;
202 write_lock(&resource_lock);
203 conflict = __request_resource(root, new);
204 write_unlock(&resource_lock);
205 return conflict ? -EBUSY : 0;
208 EXPORT_SYMBOL(request_resource);
211 * release_resource - release a previously reserved resource
212 * @old: resource pointer
214 int release_resource(struct resource *old)
216 int retval;
218 write_lock(&resource_lock);
219 retval = __release_resource(old);
220 write_unlock(&resource_lock);
221 return retval;
224 EXPORT_SYMBOL(release_resource);
226 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
228 * Finds the lowest memory reosurce exists within [res->start.res->end)
229 * the caller must specify res->start, res->end, res->flags and "name".
230 * If found, returns 0, res is overwritten, if not found, returns -1.
232 static int find_next_system_ram(struct resource *res, char *name)
234 resource_size_t start, end;
235 struct resource *p;
237 BUG_ON(!res);
239 start = res->start;
240 end = res->end;
241 BUG_ON(start >= end);
243 read_lock(&resource_lock);
244 for (p = iomem_resource.child; p ; p = p->sibling) {
245 /* system ram is just marked as IORESOURCE_MEM */
246 if (p->flags != res->flags)
247 continue;
248 if (name && strcmp(p->name, name))
249 continue;
250 if (p->start > end) {
251 p = NULL;
252 break;
254 if ((p->end >= start) && (p->start < end))
255 break;
257 read_unlock(&resource_lock);
258 if (!p)
259 return -1;
260 /* copy data */
261 if (res->start < p->start)
262 res->start = p->start;
263 if (res->end > p->end)
264 res->end = p->end;
265 return 0;
269 * This function calls callback against all memory range of "System RAM"
270 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
271 * Now, this function is only for "System RAM".
273 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
274 void *arg, int (*func)(unsigned long, unsigned long, void *))
276 struct resource res;
277 unsigned long pfn, len;
278 u64 orig_end;
279 int ret = -1;
281 res.start = (u64) start_pfn << PAGE_SHIFT;
282 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
283 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
284 orig_end = res.end;
285 while ((res.start < res.end) &&
286 (find_next_system_ram(&res, "System RAM") >= 0)) {
287 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
288 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
289 ret = (*func)(pfn, len, arg);
290 if (ret)
291 break;
292 res.start = res.end + 1;
293 res.end = orig_end;
295 return ret;
298 #endif
301 * Find empty slot in the resource tree given range and alignment.
303 static int find_resource(struct resource *root, struct resource *new,
304 resource_size_t size, resource_size_t min,
305 resource_size_t max, resource_size_t align,
306 void (*alignf)(void *, struct resource *,
307 resource_size_t, resource_size_t),
308 void *alignf_data)
310 struct resource *this = root->child;
312 new->start = root->start;
314 * Skip past an allocated resource that starts at 0, since the assignment
315 * of this->start - 1 to new->end below would cause an underflow.
317 if (this && this->start == 0) {
318 new->start = this->end + 1;
319 this = this->sibling;
321 for(;;) {
322 if (this)
323 new->end = this->start - 1;
324 else
325 new->end = root->end;
326 if (new->start < min)
327 new->start = min;
328 if (new->end > max)
329 new->end = max;
330 new->start = ALIGN(new->start, align);
331 if (alignf)
332 alignf(alignf_data, new, size, align);
333 if (new->start < new->end && new->end - new->start >= size - 1) {
334 new->end = new->start + size - 1;
335 return 0;
337 if (!this)
338 break;
339 new->start = this->end + 1;
340 this = this->sibling;
342 return -EBUSY;
346 * allocate_resource - allocate empty slot in the resource tree given range & alignment
347 * @root: root resource descriptor
348 * @new: resource descriptor desired by caller
349 * @size: requested resource region size
350 * @min: minimum size to allocate
351 * @max: maximum size to allocate
352 * @align: alignment requested, in bytes
353 * @alignf: alignment function, optional, called if not NULL
354 * @alignf_data: arbitrary data to pass to the @alignf function
356 int allocate_resource(struct resource *root, struct resource *new,
357 resource_size_t size, resource_size_t min,
358 resource_size_t max, resource_size_t align,
359 void (*alignf)(void *, struct resource *,
360 resource_size_t, resource_size_t),
361 void *alignf_data)
363 int err;
365 write_lock(&resource_lock);
366 err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
367 if (err >= 0 && __request_resource(root, new))
368 err = -EBUSY;
369 write_unlock(&resource_lock);
370 return err;
373 EXPORT_SYMBOL(allocate_resource);
376 * Insert a resource into the resource tree. If successful, return NULL,
377 * otherwise return the conflicting resource (compare to __request_resource())
379 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
381 struct resource *first, *next;
383 for (;; parent = first) {
384 first = __request_resource(parent, new);
385 if (!first)
386 return first;
388 if (first == parent)
389 return first;
391 if ((first->start > new->start) || (first->end < new->end))
392 break;
393 if ((first->start == new->start) && (first->end == new->end))
394 break;
397 for (next = first; ; next = next->sibling) {
398 /* Partial overlap? Bad, and unfixable */
399 if (next->start < new->start || next->end > new->end)
400 return next;
401 if (!next->sibling)
402 break;
403 if (next->sibling->start > new->end)
404 break;
407 new->parent = parent;
408 new->sibling = next->sibling;
409 new->child = first;
411 next->sibling = NULL;
412 for (next = first; next; next = next->sibling)
413 next->parent = new;
415 if (parent->child == first) {
416 parent->child = new;
417 } else {
418 next = parent->child;
419 while (next->sibling != first)
420 next = next->sibling;
421 next->sibling = new;
423 return NULL;
427 * insert_resource - Inserts a resource in the resource tree
428 * @parent: parent of the new resource
429 * @new: new resource to insert
431 * Returns 0 on success, -EBUSY if the resource can't be inserted.
433 * This function is equivalent to request_resource when no conflict
434 * happens. If a conflict happens, and the conflicting resources
435 * entirely fit within the range of the new resource, then the new
436 * resource is inserted and the conflicting resources become children of
437 * the new resource.
439 int insert_resource(struct resource *parent, struct resource *new)
441 struct resource *conflict;
443 write_lock(&resource_lock);
444 conflict = __insert_resource(parent, new);
445 write_unlock(&resource_lock);
446 return conflict ? -EBUSY : 0;
450 * insert_resource_expand_to_fit - Insert a resource into the resource tree
451 * @root: root resource descriptor
452 * @new: new resource to insert
454 * Insert a resource into the resource tree, possibly expanding it in order
455 * to make it encompass any conflicting resources.
457 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
459 if (new->parent)
460 return;
462 write_lock(&resource_lock);
463 for (;;) {
464 struct resource *conflict;
466 conflict = __insert_resource(root, new);
467 if (!conflict)
468 break;
469 if (conflict == root)
470 break;
472 /* Ok, expand resource to cover the conflict, then try again .. */
473 if (conflict->start < new->start)
474 new->start = conflict->start;
475 if (conflict->end > new->end)
476 new->end = conflict->end;
478 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
480 write_unlock(&resource_lock);
484 * adjust_resource - modify a resource's start and size
485 * @res: resource to modify
486 * @start: new start value
487 * @size: new size
489 * Given an existing resource, change its start and size to match the
490 * arguments. Returns 0 on success, -EBUSY if it can't fit.
491 * Existing children of the resource are assumed to be immutable.
493 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
495 struct resource *tmp, *parent = res->parent;
496 resource_size_t end = start + size - 1;
497 int result = -EBUSY;
499 write_lock(&resource_lock);
501 if ((start < parent->start) || (end > parent->end))
502 goto out;
504 for (tmp = res->child; tmp; tmp = tmp->sibling) {
505 if ((tmp->start < start) || (tmp->end > end))
506 goto out;
509 if (res->sibling && (res->sibling->start <= end))
510 goto out;
512 tmp = parent->child;
513 if (tmp != res) {
514 while (tmp->sibling != res)
515 tmp = tmp->sibling;
516 if (start <= tmp->end)
517 goto out;
520 res->start = start;
521 res->end = end;
522 result = 0;
524 out:
525 write_unlock(&resource_lock);
526 return result;
529 static void __init __reserve_region_with_split(struct resource *root,
530 resource_size_t start, resource_size_t end,
531 const char *name)
533 struct resource *parent = root;
534 struct resource *conflict;
535 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
537 if (!res)
538 return;
540 res->name = name;
541 res->start = start;
542 res->end = end;
543 res->flags = IORESOURCE_BUSY;
545 conflict = __request_resource(parent, res);
546 if (!conflict)
547 return;
549 /* failed, split and try again */
550 kfree(res);
552 /* conflict covered whole area */
553 if (conflict->start <= start && conflict->end >= end)
554 return;
556 if (conflict->start > start)
557 __reserve_region_with_split(root, start, conflict->start-1, name);
558 if (conflict->end < end)
559 __reserve_region_with_split(root, conflict->end+1, end, name);
562 void __init reserve_region_with_split(struct resource *root,
563 resource_size_t start, resource_size_t end,
564 const char *name)
566 write_lock(&resource_lock);
567 __reserve_region_with_split(root, start, end, name);
568 write_unlock(&resource_lock);
571 EXPORT_SYMBOL(adjust_resource);
574 * resource_alignment - calculate resource's alignment
575 * @res: resource pointer
577 * Returns alignment on success, 0 (invalid alignment) on failure.
579 resource_size_t resource_alignment(struct resource *res)
581 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
582 case IORESOURCE_SIZEALIGN:
583 return resource_size(res);
584 case IORESOURCE_STARTALIGN:
585 return res->start;
586 default:
587 return 0;
592 * This is compatibility stuff for IO resources.
594 * Note how this, unlike the above, knows about
595 * the IO flag meanings (busy etc).
597 * request_region creates a new busy region.
599 * check_region returns non-zero if the area is already busy.
601 * release_region releases a matching busy region.
605 * __request_region - create a new busy resource region
606 * @parent: parent resource descriptor
607 * @start: resource start address
608 * @n: resource region size
609 * @name: reserving caller's ID string
610 * @flags: IO resource flags
612 struct resource * __request_region(struct resource *parent,
613 resource_size_t start, resource_size_t n,
614 const char *name, int flags)
616 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
618 if (!res)
619 return NULL;
621 res->name = name;
622 res->start = start;
623 res->end = start + n - 1;
624 res->flags = IORESOURCE_BUSY;
625 res->flags |= flags;
627 write_lock(&resource_lock);
629 for (;;) {
630 struct resource *conflict;
632 conflict = __request_resource(parent, res);
633 if (!conflict)
634 break;
635 if (conflict != parent) {
636 parent = conflict;
637 if (!(conflict->flags & IORESOURCE_BUSY))
638 continue;
641 /* Uhhuh, that didn't work out.. */
642 kfree(res);
643 res = NULL;
644 break;
646 write_unlock(&resource_lock);
647 return res;
649 EXPORT_SYMBOL(__request_region);
652 * __check_region - check if a resource region is busy or free
653 * @parent: parent resource descriptor
654 * @start: resource start address
655 * @n: resource region size
657 * Returns 0 if the region is free at the moment it is checked,
658 * returns %-EBUSY if the region is busy.
660 * NOTE:
661 * This function is deprecated because its use is racy.
662 * Even if it returns 0, a subsequent call to request_region()
663 * may fail because another driver etc. just allocated the region.
664 * Do NOT use it. It will be removed from the kernel.
666 int __check_region(struct resource *parent, resource_size_t start,
667 resource_size_t n)
669 struct resource * res;
671 res = __request_region(parent, start, n, "check-region", 0);
672 if (!res)
673 return -EBUSY;
675 release_resource(res);
676 kfree(res);
677 return 0;
679 EXPORT_SYMBOL(__check_region);
682 * __release_region - release a previously reserved resource region
683 * @parent: parent resource descriptor
684 * @start: resource start address
685 * @n: resource region size
687 * The described resource region must match a currently busy region.
689 void __release_region(struct resource *parent, resource_size_t start,
690 resource_size_t n)
692 struct resource **p;
693 resource_size_t end;
695 p = &parent->child;
696 end = start + n - 1;
698 write_lock(&resource_lock);
700 for (;;) {
701 struct resource *res = *p;
703 if (!res)
704 break;
705 if (res->start <= start && res->end >= end) {
706 if (!(res->flags & IORESOURCE_BUSY)) {
707 p = &res->child;
708 continue;
710 if (res->start != start || res->end != end)
711 break;
712 *p = res->sibling;
713 write_unlock(&resource_lock);
714 kfree(res);
715 return;
717 p = &res->sibling;
720 write_unlock(&resource_lock);
722 printk(KERN_WARNING "Trying to free nonexistent resource "
723 "<%016llx-%016llx>\n", (unsigned long long)start,
724 (unsigned long long)end);
726 EXPORT_SYMBOL(__release_region);
729 * Managed region resource
731 struct region_devres {
732 struct resource *parent;
733 resource_size_t start;
734 resource_size_t n;
737 static void devm_region_release(struct device *dev, void *res)
739 struct region_devres *this = res;
741 __release_region(this->parent, this->start, this->n);
744 static int devm_region_match(struct device *dev, void *res, void *match_data)
746 struct region_devres *this = res, *match = match_data;
748 return this->parent == match->parent &&
749 this->start == match->start && this->n == match->n;
752 struct resource * __devm_request_region(struct device *dev,
753 struct resource *parent, resource_size_t start,
754 resource_size_t n, const char *name)
756 struct region_devres *dr = NULL;
757 struct resource *res;
759 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
760 GFP_KERNEL);
761 if (!dr)
762 return NULL;
764 dr->parent = parent;
765 dr->start = start;
766 dr->n = n;
768 res = __request_region(parent, start, n, name, 0);
769 if (res)
770 devres_add(dev, dr);
771 else
772 devres_free(dr);
774 return res;
776 EXPORT_SYMBOL(__devm_request_region);
778 void __devm_release_region(struct device *dev, struct resource *parent,
779 resource_size_t start, resource_size_t n)
781 struct region_devres match_data = { parent, start, n };
783 __release_region(parent, start, n);
784 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
785 &match_data));
787 EXPORT_SYMBOL(__devm_release_region);
790 * Called from init/main.c to reserve IO ports.
792 #define MAXRESERVE 4
793 static int __init reserve_setup(char *str)
795 static int reserved;
796 static struct resource reserve[MAXRESERVE];
798 for (;;) {
799 unsigned int io_start, io_num;
800 int x = reserved;
802 if (get_option (&str, &io_start) != 2)
803 break;
804 if (get_option (&str, &io_num) == 0)
805 break;
806 if (x < MAXRESERVE) {
807 struct resource *res = reserve + x;
808 res->name = "reserved";
809 res->start = io_start;
810 res->end = io_start + io_num - 1;
811 res->flags = IORESOURCE_BUSY;
812 res->child = NULL;
813 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
814 reserved = x+1;
817 return 1;
820 __setup("reserve=", reserve_setup);
823 * Check if the requested addr and size spans more than any slot in the
824 * iomem resource tree.
826 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
828 struct resource *p = &iomem_resource;
829 int err = 0;
830 loff_t l;
832 read_lock(&resource_lock);
833 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
835 * We can probably skip the resources without
836 * IORESOURCE_IO attribute?
838 if (p->start >= addr + size)
839 continue;
840 if (p->end < addr)
841 continue;
842 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
843 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
844 continue;
846 * if a resource is "BUSY", it's not a hardware resource
847 * but a driver mapping of such a resource; we don't want
848 * to warn for those; some drivers legitimately map only
849 * partial hardware resources. (example: vesafb)
851 if (p->flags & IORESOURCE_BUSY)
852 continue;
854 printk(KERN_WARNING "resource map sanity check conflict: "
855 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
856 (unsigned long long)addr,
857 (unsigned long long)(addr + size - 1),
858 (unsigned long long)p->start,
859 (unsigned long long)p->end,
860 p->name);
861 err = -1;
862 break;
864 read_unlock(&resource_lock);
866 return err;
869 #ifdef CONFIG_STRICT_DEVMEM
870 static int strict_iomem_checks = 1;
871 #else
872 static int strict_iomem_checks;
873 #endif
876 * check if an address is reserved in the iomem resource tree
877 * returns 1 if reserved, 0 if not reserved.
879 int iomem_is_exclusive(u64 addr)
881 struct resource *p = &iomem_resource;
882 int err = 0;
883 loff_t l;
884 int size = PAGE_SIZE;
886 if (!strict_iomem_checks)
887 return 0;
889 addr = addr & PAGE_MASK;
891 read_lock(&resource_lock);
892 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
894 * We can probably skip the resources without
895 * IORESOURCE_IO attribute?
897 if (p->start >= addr + size)
898 break;
899 if (p->end < addr)
900 continue;
901 if (p->flags & IORESOURCE_BUSY &&
902 p->flags & IORESOURCE_EXCLUSIVE) {
903 err = 1;
904 break;
907 read_unlock(&resource_lock);
909 return err;
912 static int __init strict_iomem(char *str)
914 if (strstr(str, "relaxed"))
915 strict_iomem_checks = 0;
916 if (strstr(str, "strict"))
917 strict_iomem_checks = 1;
918 return 1;
921 __setup("iomem=", strict_iomem);