Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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*lx-%0*lx : %s\n", |
| 87 | depth * 2, "", |
| 88 | width, r->start, |
| 89 | width, 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 | unsigned long start = new->start; |
| 155 | unsigned long 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 | unsigned long size, |
| 240 | unsigned long min, unsigned long max, |
| 241 | unsigned long align, |
| 242 | void (*alignf)(void *, struct resource *, |
| 243 | unsigned long, unsigned long), |
| 244 | void *alignf_data) |
| 245 | { |
| 246 | struct resource *this = root->child; |
| 247 | |
| 248 | new->start = root->start; |
| 249 | /* |
| 250 | * Skip past an allocated resource that starts at 0, since the assignment |
| 251 | * of this->start - 1 to new->end below would cause an underflow. |
| 252 | */ |
| 253 | if (this && this->start == 0) { |
| 254 | new->start = this->end + 1; |
| 255 | this = this->sibling; |
| 256 | } |
| 257 | for(;;) { |
| 258 | if (this) |
| 259 | new->end = this->start - 1; |
| 260 | else |
| 261 | new->end = root->end; |
| 262 | if (new->start < min) |
| 263 | new->start = min; |
| 264 | if (new->end > max) |
| 265 | new->end = max; |
Nick Wilson | 8c0e33c | 2005-06-25 14:59:00 -0700 | [diff] [blame] | 266 | new->start = ALIGN(new->start, align); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | if (alignf) |
| 268 | alignf(alignf_data, new, size, align); |
Lennert Buytenhek | b52402c | 2005-04-16 15:25:58 -0700 | [diff] [blame] | 269 | if (new->start < new->end && new->end - new->start >= size - 1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | new->end = new->start + size - 1; |
| 271 | return 0; |
| 272 | } |
| 273 | if (!this) |
| 274 | break; |
| 275 | new->start = this->end + 1; |
| 276 | this = this->sibling; |
| 277 | } |
| 278 | return -EBUSY; |
| 279 | } |
| 280 | |
| 281 | /* |
| 282 | * Allocate empty slot in the resource tree given range and alignment. |
| 283 | */ |
| 284 | int allocate_resource(struct resource *root, struct resource *new, |
| 285 | unsigned long size, |
| 286 | unsigned long min, unsigned long max, |
| 287 | unsigned long align, |
| 288 | void (*alignf)(void *, struct resource *, |
| 289 | unsigned long, unsigned long), |
| 290 | void *alignf_data) |
| 291 | { |
| 292 | int err; |
| 293 | |
| 294 | write_lock(&resource_lock); |
| 295 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); |
| 296 | if (err >= 0 && __request_resource(root, new)) |
| 297 | err = -EBUSY; |
| 298 | write_unlock(&resource_lock); |
| 299 | return err; |
| 300 | } |
| 301 | |
| 302 | EXPORT_SYMBOL(allocate_resource); |
| 303 | |
| 304 | /** |
| 305 | * insert_resource - Inserts a resource in the resource tree |
| 306 | * @parent: parent of the new resource |
| 307 | * @new: new resource to insert |
| 308 | * |
| 309 | * Returns 0 on success, -EBUSY if the resource can't be inserted. |
| 310 | * |
| 311 | * This function is equivalent of request_resource when no conflict |
| 312 | * happens. If a conflict happens, and the conflicting resources |
| 313 | * entirely fit within the range of the new resource, then the new |
| 314 | * resource is inserted and the conflicting resources become childs of |
| 315 | * the new resource. Otherwise the new resource becomes the child of |
| 316 | * the conflicting resource |
| 317 | */ |
| 318 | int insert_resource(struct resource *parent, struct resource *new) |
| 319 | { |
| 320 | int result; |
| 321 | struct resource *first, *next; |
| 322 | |
| 323 | write_lock(&resource_lock); |
| 324 | begin: |
| 325 | result = 0; |
| 326 | first = __request_resource(parent, new); |
| 327 | if (!first) |
| 328 | goto out; |
| 329 | |
| 330 | result = -EBUSY; |
| 331 | if (first == parent) |
| 332 | goto out; |
| 333 | |
| 334 | /* Resource fully contained by the clashing resource? Recurse into it */ |
| 335 | if (first->start <= new->start && first->end >= new->end) { |
| 336 | parent = first; |
| 337 | goto begin; |
| 338 | } |
| 339 | |
| 340 | for (next = first; ; next = next->sibling) { |
| 341 | /* Partial overlap? Bad, and unfixable */ |
| 342 | if (next->start < new->start || next->end > new->end) |
| 343 | goto out; |
| 344 | if (!next->sibling) |
| 345 | break; |
| 346 | if (next->sibling->start > new->end) |
| 347 | break; |
| 348 | } |
| 349 | |
| 350 | result = 0; |
| 351 | |
| 352 | new->parent = parent; |
| 353 | new->sibling = next->sibling; |
| 354 | new->child = first; |
| 355 | |
| 356 | next->sibling = NULL; |
| 357 | for (next = first; next; next = next->sibling) |
| 358 | next->parent = new; |
| 359 | |
| 360 | if (parent->child == first) { |
| 361 | parent->child = new; |
| 362 | } else { |
| 363 | next = parent->child; |
| 364 | while (next->sibling != first) |
| 365 | next = next->sibling; |
| 366 | next->sibling = new; |
| 367 | } |
| 368 | |
| 369 | out: |
| 370 | write_unlock(&resource_lock); |
| 371 | return result; |
| 372 | } |
| 373 | |
| 374 | EXPORT_SYMBOL(insert_resource); |
| 375 | |
| 376 | /* |
| 377 | * Given an existing resource, change its start and size to match the |
| 378 | * arguments. Returns -EBUSY if it can't fit. Existing children of |
| 379 | * the resource are assumed to be immutable. |
| 380 | */ |
| 381 | int adjust_resource(struct resource *res, unsigned long start, unsigned long size) |
| 382 | { |
| 383 | struct resource *tmp, *parent = res->parent; |
| 384 | unsigned long end = start + size - 1; |
| 385 | int result = -EBUSY; |
| 386 | |
| 387 | write_lock(&resource_lock); |
| 388 | |
| 389 | if ((start < parent->start) || (end > parent->end)) |
| 390 | goto out; |
| 391 | |
| 392 | for (tmp = res->child; tmp; tmp = tmp->sibling) { |
| 393 | if ((tmp->start < start) || (tmp->end > end)) |
| 394 | goto out; |
| 395 | } |
| 396 | |
| 397 | if (res->sibling && (res->sibling->start <= end)) |
| 398 | goto out; |
| 399 | |
| 400 | tmp = parent->child; |
| 401 | if (tmp != res) { |
| 402 | while (tmp->sibling != res) |
| 403 | tmp = tmp->sibling; |
| 404 | if (start <= tmp->end) |
| 405 | goto out; |
| 406 | } |
| 407 | |
| 408 | res->start = start; |
| 409 | res->end = end; |
| 410 | result = 0; |
| 411 | |
| 412 | out: |
| 413 | write_unlock(&resource_lock); |
| 414 | return result; |
| 415 | } |
| 416 | |
| 417 | EXPORT_SYMBOL(adjust_resource); |
| 418 | |
| 419 | /* |
| 420 | * This is compatibility stuff for IO resources. |
| 421 | * |
| 422 | * Note how this, unlike the above, knows about |
| 423 | * the IO flag meanings (busy etc). |
| 424 | * |
| 425 | * Request-region creates a new busy region. |
| 426 | * |
| 427 | * Check-region returns non-zero if the area is already busy |
| 428 | * |
| 429 | * Release-region releases a matching busy region. |
| 430 | */ |
| 431 | struct resource * __request_region(struct resource *parent, unsigned long start, unsigned long n, const char *name) |
| 432 | { |
Pekka J Enberg | dd39271 | 2005-09-06 15:18:31 -0700 | [diff] [blame] | 433 | struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | |
| 435 | if (res) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Adrian Bunk | d974837 | 2006-01-09 20:54:49 -0800 | [diff] [blame] | 467 | int __check_region(struct resource *parent, unsigned long start, unsigned long n) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | { |
| 469 | struct resource * res; |
| 470 | |
| 471 | res = __request_region(parent, start, n, "check-region"); |
| 472 | if (!res) |
| 473 | return -EBUSY; |
| 474 | |
| 475 | release_resource(res); |
| 476 | kfree(res); |
| 477 | return 0; |
| 478 | } |
| 479 | |
| 480 | EXPORT_SYMBOL(__check_region); |
| 481 | |
| 482 | void __release_region(struct resource *parent, unsigned long start, unsigned long n) |
| 483 | { |
| 484 | struct resource **p; |
| 485 | unsigned long end; |
| 486 | |
| 487 | p = &parent->child; |
| 488 | end = start + n - 1; |
| 489 | |
| 490 | write_lock(&resource_lock); |
| 491 | |
| 492 | for (;;) { |
| 493 | struct resource *res = *p; |
| 494 | |
| 495 | if (!res) |
| 496 | break; |
| 497 | if (res->start <= start && res->end >= end) { |
| 498 | if (!(res->flags & IORESOURCE_BUSY)) { |
| 499 | p = &res->child; |
| 500 | continue; |
| 501 | } |
| 502 | if (res->start != start || res->end != end) |
| 503 | break; |
| 504 | *p = res->sibling; |
| 505 | write_unlock(&resource_lock); |
| 506 | kfree(res); |
| 507 | return; |
| 508 | } |
| 509 | p = &res->sibling; |
| 510 | } |
| 511 | |
| 512 | write_unlock(&resource_lock); |
| 513 | |
| 514 | printk(KERN_WARNING "Trying to free nonexistent resource <%08lx-%08lx>\n", start, end); |
| 515 | } |
| 516 | |
| 517 | EXPORT_SYMBOL(__release_region); |
| 518 | |
| 519 | /* |
| 520 | * Called from init/main.c to reserve IO ports. |
| 521 | */ |
| 522 | #define MAXRESERVE 4 |
| 523 | static int __init reserve_setup(char *str) |
| 524 | { |
| 525 | static int reserved; |
| 526 | static struct resource reserve[MAXRESERVE]; |
| 527 | |
| 528 | for (;;) { |
| 529 | int io_start, io_num; |
| 530 | int x = reserved; |
| 531 | |
| 532 | if (get_option (&str, &io_start) != 2) |
| 533 | break; |
| 534 | if (get_option (&str, &io_num) == 0) |
| 535 | break; |
| 536 | if (x < MAXRESERVE) { |
| 537 | struct resource *res = reserve + x; |
| 538 | res->name = "reserved"; |
| 539 | res->start = io_start; |
| 540 | res->end = io_start + io_num - 1; |
| 541 | res->flags = IORESOURCE_BUSY; |
| 542 | res->child = NULL; |
| 543 | if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) |
| 544 | reserved = x+1; |
| 545 | } |
| 546 | } |
| 547 | return 1; |
| 548 | } |
| 549 | |
| 550 | __setup("reserve=", reserve_setup); |