54835c02ab37038c2ad4f5bd35d344240013437f
[linux-2.6.git] / kernel / resource.c
1 /*
2  *      linux/kernel/resource.c
3  *
4  * Copyright (C) 1999   Linus Torvalds
5  * Copyright (C) 1999   Martin Mares <mj@ucw.cz>
6  *
7  * Arbitrary resource management.
8  */
9
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>
18 #include <linux/fs.h>
19 #include <linux/proc_fs.h>
20 #include <linux/seq_file.h>
21 #include <asm/io.h>
22
23
24 struct resource ioport_resource = {
25         .name   = "PCI IO",
26         .start  = 0x0000,
27         .end    = IO_SPACE_LIMIT,
28         .flags  = IORESOURCE_IO,
29 };
30
31 EXPORT_SYMBOL(ioport_resource);
32
33 struct resource iomem_resource = {
34         .name   = "PCI mem",
35         .start  = 0UL,
36         .end    = ~0UL,
37         .flags  = IORESOURCE_MEM,
38 };
39
40 EXPORT_SYMBOL(iomem_resource);
41
42 static DEFINE_RWLOCK(resource_lock);
43
44 #ifdef CONFIG_PROC_FS
45
46 enum { MAX_IORES_LEVEL = 5 };
47
48 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
49 {
50         struct resource *p = v;
51         (*pos)++;
52         if (p->child)
53                 return p->child;
54         while (!p->sibling && p->parent)
55                 p = p->parent;
56         return p->sibling;
57 }
58
59 static void *r_start(struct seq_file *m, loff_t *pos)
60         __acquires(resource_lock)
61 {
62         struct resource *p = m->private;
63         loff_t l = 0;
64         read_lock(&resource_lock);
65         for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
66                 ;
67         return p;
68 }
69
70 static void r_stop(struct seq_file *m, void *v)
71         __releases(resource_lock)
72 {
73         read_unlock(&resource_lock);
74 }
75
76 static int r_show(struct seq_file *m, void *v)
77 {
78         struct resource *root = m->private;
79         struct resource *r = v, *p;
80         int width = root->end < 0x10000 ? 4 : 8;
81         int depth;
82
83         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
84                 if (p->parent == root)
85                         break;
86         seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
87                         depth * 2, "",
88                         width, (unsigned long long) r->start,
89                         width, (unsigned long long) r->end,
90                         r->name ? r->name : "<BAD>");
91         return 0;
92 }
93
94 static struct seq_operations resource_op = {
95         .start  = r_start,
96         .next   = r_next,
97         .stop   = r_stop,
98         .show   = r_show,
99 };
100
101 static int ioports_open(struct inode *inode, struct file *file)
102 {
103         int res = seq_open(file, &resource_op);
104         if (!res) {
105                 struct seq_file *m = file->private_data;
106                 m->private = &ioport_resource;
107         }
108         return res;
109 }
110
111 static int iomem_open(struct inode *inode, struct file *file)
112 {
113         int res = seq_open(file, &resource_op);
114         if (!res) {
115                 struct seq_file *m = file->private_data;
116                 m->private = &iomem_resource;
117         }
118         return res;
119 }
120
121 static struct file_operations proc_ioports_operations = {
122         .open           = ioports_open,
123         .read           = seq_read,
124         .llseek         = seq_lseek,
125         .release        = seq_release,
126 };
127
128 static struct file_operations proc_iomem_operations = {
129         .open           = iomem_open,
130         .read           = seq_read,
131         .llseek         = seq_lseek,
132         .release        = seq_release,
133 };
134
135 static int __init ioresources_init(void)
136 {
137         struct proc_dir_entry *entry;
138
139         entry = create_proc_entry("ioports", 0, NULL);
140         if (entry)
141                 entry->proc_fops = &proc_ioports_operations;
142         entry = create_proc_entry("iomem", 0, NULL);
143         if (entry)
144                 entry->proc_fops = &proc_iomem_operations;
145         return 0;
146 }
147 __initcall(ioresources_init);
148
149 #endif /* CONFIG_PROC_FS */
150
151 /* Return the conflict entry if you can't request it */
152 static struct resource * __request_resource(struct resource *root, struct resource *new)
153 {
154         resource_size_t start = new->start;
155         resource_size_t end = new->end;
156         struct resource *tmp, **p;
157
158         if (end < start)
159                 return root;
160         if (start < root->start)
161                 return root;
162         if (end > root->end)
163                 return root;
164         p = &root->child;
165         for (;;) {
166                 tmp = *p;
167                 if (!tmp || tmp->start > end) {
168                         new->sibling = tmp;
169                         *p = new;
170                         new->parent = root;
171                         return NULL;
172                 }
173                 p = &tmp->sibling;
174                 if (tmp->end < start)
175                         continue;
176                 return tmp;
177         }
178 }
179
180 static int __release_resource(struct resource *old)
181 {
182         struct resource *tmp, **p;
183
184         p = &old->parent->child;
185         for (;;) {
186                 tmp = *p;
187                 if (!tmp)
188                         break;
189                 if (tmp == old) {
190                         *p = tmp->sibling;
191                         old->parent = NULL;
192                         return 0;
193                 }
194                 p = &tmp->sibling;
195         }
196         return -EINVAL;
197 }
198
199 int request_resource(struct resource *root, struct resource *new)
200 {
201         struct resource *conflict;
202
203         write_lock(&resource_lock);
204         conflict = __request_resource(root, new);
205         write_unlock(&resource_lock);
206         return conflict ? -EBUSY : 0;
207 }
208
209 EXPORT_SYMBOL(request_resource);
210
211 struct resource *____request_resource(struct resource *root, struct resource *new)
212 {
213         struct resource *conflict;
214
215         write_lock(&resource_lock);
216         conflict = __request_resource(root, new);
217         write_unlock(&resource_lock);
218         return conflict;
219 }
220
221 EXPORT_SYMBOL(____request_resource);
222
223 int release_resource(struct resource *old)
224 {
225         int retval;
226
227         write_lock(&resource_lock);
228         retval = __release_resource(old);
229         write_unlock(&resource_lock);
230         return retval;
231 }
232
233 EXPORT_SYMBOL(release_resource);
234
235 /*
236  * Find empty slot in the resource tree given range and alignment.
237  */
238 static int find_resource(struct resource *root, struct resource *new,
239                          resource_size_t size, resource_size_t min,
240                          resource_size_t max, resource_size_t align,
241                          void (*alignf)(void *, struct resource *,
242                                         resource_size_t, resource_size_t),
243                          void *alignf_data)
244 {
245         struct resource *this = root->child;
246
247         new->start = root->start;
248         /*
249          * Skip past an allocated resource that starts at 0, since the assignment
250          * of this->start - 1 to new->end below would cause an underflow.
251          */
252         if (this && this->start == 0) {
253                 new->start = this->end + 1;
254                 this = this->sibling;
255         }
256         for(;;) {
257                 if (this)
258                         new->end = this->start - 1;
259                 else
260                         new->end = root->end;
261                 if (new->start < min)
262                         new->start = min;
263                 if (new->end > max)
264                         new->end = max;
265                 new->start = ALIGN(new->start, align);
266                 if (alignf)
267                         alignf(alignf_data, new, size, align);
268                 if (new->start < new->end && new->end - new->start >= size - 1) {
269                         new->end = new->start + size - 1;
270                         return 0;
271                 }
272                 if (!this)
273                         break;
274                 new->start = this->end + 1;
275                 this = this->sibling;
276         }
277         return -EBUSY;
278 }
279
280 /*
281  * Allocate empty slot in the resource tree given range and alignment.
282  */
283 int allocate_resource(struct resource *root, struct resource *new,
284                       resource_size_t size, resource_size_t min,
285                       resource_size_t max, resource_size_t align,
286                       void (*alignf)(void *, struct resource *,
287                                      resource_size_t, resource_size_t),
288                       void *alignf_data)
289 {
290         int err;
291
292         write_lock(&resource_lock);
293         err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
294         if (err >= 0 && __request_resource(root, new))
295                 err = -EBUSY;
296         write_unlock(&resource_lock);
297         return err;
298 }
299
300 EXPORT_SYMBOL(allocate_resource);
301
302 /**
303  * insert_resource - Inserts a resource in the resource tree
304  * @parent: parent of the new resource
305  * @new: new resource to insert
306  *
307  * Returns 0 on success, -EBUSY if the resource can't be inserted.
308  *
309  * This function is equivalent of request_resource when no conflict
310  * happens. If a conflict happens, and the conflicting resources
311  * entirely fit within the range of the new resource, then the new
312  * resource is inserted and the conflicting resources become childs of
313  * the new resource.  Otherwise the new resource becomes the child of
314  * the conflicting resource
315  */
316 int insert_resource(struct resource *parent, struct resource *new)
317 {
318         int result;
319         struct resource *first, *next;
320
321         write_lock(&resource_lock);
322  begin:
323         result = 0;
324         first = __request_resource(parent, new);
325         if (!first)
326                 goto out;
327
328         result = -EBUSY;
329         if (first == parent)
330                 goto out;
331
332         /* Resource fully contained by the clashing resource? Recurse into it */
333         if (first->start <= new->start && first->end >= new->end) {
334                 parent = first;
335                 goto begin;
336         }
337
338         for (next = first; ; next = next->sibling) {
339                 /* Partial overlap? Bad, and unfixable */
340                 if (next->start < new->start || next->end > new->end)
341                         goto out;
342                 if (!next->sibling)
343                         break;
344                 if (next->sibling->start > new->end)
345                         break;
346         }
347
348         result = 0;
349
350         new->parent = parent;
351         new->sibling = next->sibling;
352         new->child = first;
353
354         next->sibling = NULL;
355         for (next = first; next; next = next->sibling)
356                 next->parent = new;
357
358         if (parent->child == first) {
359                 parent->child = new;
360         } else {
361                 next = parent->child;
362                 while (next->sibling != first)
363                         next = next->sibling;
364                 next->sibling = new;
365         }
366
367  out:
368         write_unlock(&resource_lock);
369         return result;
370 }
371
372 EXPORT_SYMBOL(insert_resource);
373
374 /*
375  * Given an existing resource, change its start and size to match the
376  * arguments.  Returns -EBUSY if it can't fit.  Existing children of
377  * the resource are assumed to be immutable.
378  */
379 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
380 {
381         struct resource *tmp, *parent = res->parent;
382         resource_size_t end = start + size - 1;
383         int result = -EBUSY;
384
385         write_lock(&resource_lock);
386
387         if ((start < parent->start) || (end > parent->end))
388                 goto out;
389
390         for (tmp = res->child; tmp; tmp = tmp->sibling) {
391                 if ((tmp->start < start) || (tmp->end > end))
392                         goto out;
393         }
394
395         if (res->sibling && (res->sibling->start <= end))
396                 goto out;
397
398         tmp = parent->child;
399         if (tmp != res) {
400                 while (tmp->sibling != res)
401                         tmp = tmp->sibling;
402                 if (start <= tmp->end)
403                         goto out;
404         }
405
406         res->start = start;
407         res->end = end;
408         result = 0;
409
410  out:
411         write_unlock(&resource_lock);
412         return result;
413 }
414
415 EXPORT_SYMBOL(adjust_resource);
416
417 /*
418  * This is compatibility stuff for IO resources.
419  *
420  * Note how this, unlike the above, knows about
421  * the IO flag meanings (busy etc).
422  *
423  * Request-region creates a new busy region.
424  *
425  * Check-region returns non-zero if the area is already busy
426  *
427  * Release-region releases a matching busy region.
428  */
429 struct resource * __request_region(struct resource *parent,
430                                    resource_size_t start, resource_size_t n,
431                                    const char *name)
432 {
433         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
434
435         if (res) {
436                 res->name = name;
437                 res->start = start;
438                 res->end = start + n - 1;
439                 res->flags = IORESOURCE_BUSY;
440
441                 write_lock(&resource_lock);
442
443                 for (;;) {
444                         struct resource *conflict;
445
446                         conflict = __request_resource(parent, res);
447                         if (!conflict)
448                                 break;
449                         if (conflict != parent) {
450                                 parent = conflict;
451                                 if (!(conflict->flags & IORESOURCE_BUSY))
452                                         continue;
453                         }
454
455                         /* Uhhuh, that didn't work out.. */
456                         kfree(res);
457                         res = NULL;
458                         break;
459                 }
460                 write_unlock(&resource_lock);
461         }
462         return res;
463 }
464
465 EXPORT_SYMBOL(__request_region);
466
467 int __check_region(struct resource *parent, resource_size_t start,
468                         resource_size_t n)
469 {
470         struct resource * res;
471
472         res = __request_region(parent, start, n, "check-region");
473         if (!res)
474                 return -EBUSY;
475
476         release_resource(res);
477         kfree(res);
478         return 0;
479 }
480
481 EXPORT_SYMBOL(__check_region);
482
483 void __release_region(struct resource *parent, resource_size_t start,
484                         resource_size_t n)
485 {
486         struct resource **p;
487         resource_size_t end;
488
489         p = &parent->child;
490         end = start + n - 1;
491
492         write_lock(&resource_lock);
493
494         for (;;) {
495                 struct resource *res = *p;
496
497                 if (!res)
498                         break;
499                 if (res->start <= start && res->end >= end) {
500                         if (!(res->flags & IORESOURCE_BUSY)) {
501                                 p = &res->child;
502                                 continue;
503                         }
504                         if (res->start != start || res->end != end)
505                                 break;
506                         *p = res->sibling;
507                         write_unlock(&resource_lock);
508                         kfree(res);
509                         return;
510                 }
511                 p = &res->sibling;
512         }
513
514         write_unlock(&resource_lock);
515
516         printk(KERN_WARNING "Trying to free nonexistent resource "
517                 "<%016llx-%016llx>\n", (unsigned long long)start,
518                 (unsigned long long)end);
519 }
520
521 EXPORT_SYMBOL(__release_region);
522
523 /*
524  * Called from init/main.c to reserve IO ports.
525  */
526 #define MAXRESERVE 4
527 static int __init reserve_setup(char *str)
528 {
529         static int reserved;
530         static struct resource reserve[MAXRESERVE];
531
532         for (;;) {
533                 int io_start, io_num;
534                 int x = reserved;
535
536                 if (get_option (&str, &io_start) != 2)
537                         break;
538                 if (get_option (&str, &io_num)   == 0)
539                         break;
540                 if (x < MAXRESERVE) {
541                         struct resource *res = reserve + x;
542                         res->name = "reserved";
543                         res->start = io_start;
544                         res->end = io_start + io_num - 1;
545                         res->flags = IORESOURCE_BUSY;
546                         res->child = NULL;
547                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
548                                 reserved = x+1;
549                 }
550         }
551         return 1;
552 }
553
554 __setup("reserve=", reserve_setup);