diff options
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 104 |
1 files changed, 10 insertions, 94 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 9fad33efd0db..798e2fae2a06 100644 --- a/kernel/resource.c +++ b/kernel/resource.c | |||
| @@ -40,23 +40,6 @@ EXPORT_SYMBOL(iomem_resource); | |||
| 40 | 40 | ||
| 41 | static DEFINE_RWLOCK(resource_lock); | 41 | static DEFINE_RWLOCK(resource_lock); |
| 42 | 42 | ||
| 43 | /* | ||
| 44 | * By default, we allocate free space bottom-up. The architecture can request | ||
| 45 | * top-down by clearing this flag. The user can override the architecture's | ||
| 46 | * choice with the "resource_alloc_from_bottom" kernel boot option, but that | ||
| 47 | * should only be a debugging tool. | ||
| 48 | */ | ||
| 49 | int resource_alloc_from_bottom = 1; | ||
| 50 | |||
| 51 | static __init int setup_alloc_from_bottom(char *s) | ||
| 52 | { | ||
| 53 | printk(KERN_INFO | ||
| 54 | "resource: allocating from bottom-up; please report a bug\n"); | ||
| 55 | resource_alloc_from_bottom = 1; | ||
| 56 | return 0; | ||
| 57 | } | ||
| 58 | early_param("resource_alloc_from_bottom", setup_alloc_from_bottom); | ||
| 59 | |||
| 60 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | 43 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) |
| 61 | { | 44 | { |
| 62 | struct resource *p = v; | 45 | struct resource *p = v; |
| @@ -374,6 +357,10 @@ int __weak page_is_ram(unsigned long pfn) | |||
| 374 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; | 357 | return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; |
| 375 | } | 358 | } |
| 376 | 359 | ||
| 360 | void __weak arch_remove_reservations(struct resource *avail) | ||
| 361 | { | ||
| 362 | } | ||
| 363 | |||
| 377 | static resource_size_t simple_align_resource(void *data, | 364 | static resource_size_t simple_align_resource(void *data, |
| 378 | const struct resource *avail, | 365 | const struct resource *avail, |
| 379 | resource_size_t size, | 366 | resource_size_t size, |
| @@ -397,74 +384,7 @@ static bool resource_contains(struct resource *res1, struct resource *res2) | |||
| 397 | } | 384 | } |
| 398 | 385 | ||
| 399 | /* | 386 | /* |
| 400 | * Find the resource before "child" in the sibling list of "root" children. | ||
| 401 | */ | ||
| 402 | static struct resource *find_sibling_prev(struct resource *root, struct resource *child) | ||
| 403 | { | ||
| 404 | struct resource *this; | ||
| 405 | |||
| 406 | for (this = root->child; this; this = this->sibling) | ||
| 407 | if (this->sibling == child) | ||
| 408 | return this; | ||
| 409 | |||
| 410 | return NULL; | ||
| 411 | } | ||
| 412 | |||
| 413 | /* | ||
| 414 | * Find empty slot in the resource tree given range and alignment. | 387 | * Find empty slot in the resource tree given range and alignment. |
| 415 | * This version allocates from the end of the root resource first. | ||
| 416 | */ | ||
| 417 | static int find_resource_from_top(struct resource *root, struct resource *new, | ||
| 418 | resource_size_t size, resource_size_t min, | ||
| 419 | resource_size_t max, resource_size_t align, | ||
| 420 | resource_size_t (*alignf)(void *, | ||
| 421 | const struct resource *, | ||
| 422 | resource_size_t, | ||
| 423 | resource_size_t), | ||
| 424 | void *alignf_data) | ||
| 425 | { | ||
| 426 | struct resource *this; | ||
| 427 | struct resource tmp, avail, alloc; | ||
| 428 | |||
| 429 | tmp.start = root->end; | ||
| 430 | tmp.end = root->end; | ||
| 431 | |||
| 432 | this = find_sibling_prev(root, NULL); | ||
| 433 | for (;;) { | ||
| 434 | if (this) { | ||
| 435 | if (this->end < root->end) | ||
| 436 | tmp.start = this->end + 1; | ||
| 437 | } else | ||
| 438 | tmp.start = root->start; | ||
| 439 | |||
| 440 | resource_clip(&tmp, min, max); | ||
| 441 | |||
| 442 | /* Check for overflow after ALIGN() */ | ||
| 443 | avail = *new; | ||
| 444 | avail.start = ALIGN(tmp.start, align); | ||
| 445 | avail.end = tmp.end; | ||
| 446 | if (avail.start >= tmp.start) { | ||
| 447 | alloc.start = alignf(alignf_data, &avail, size, align); | ||
| 448 | alloc.end = alloc.start + size - 1; | ||
| 449 | if (resource_contains(&avail, &alloc)) { | ||
| 450 | new->start = alloc.start; | ||
| 451 | new->end = alloc.end; | ||
| 452 | return 0; | ||
| 453 | } | ||
| 454 | } | ||
| 455 | |||
| 456 | if (!this || this->start == root->start) | ||
| 457 | break; | ||
| 458 | |||
| 459 | tmp.end = this->start - 1; | ||
| 460 | this = find_sibling_prev(root, this); | ||
| 461 | } | ||
| 462 | return -EBUSY; | ||
| 463 | } | ||
| 464 | |||
| 465 | /* | ||
| 466 | * Find empty slot in the resource tree given range and alignment. | ||
| 467 | * This version allocates from the beginning of the root resource first. | ||
| 468 | */ | 388 | */ |
| 469 | static int find_resource(struct resource *root, struct resource *new, | 389 | static int find_resource(struct resource *root, struct resource *new, |
| 470 | resource_size_t size, resource_size_t min, | 390 | resource_size_t size, resource_size_t min, |
| @@ -478,23 +398,24 @@ static int find_resource(struct resource *root, struct resource *new, | |||
| 478 | struct resource *this = root->child; | 398 | struct resource *this = root->child; |
| 479 | struct resource tmp = *new, avail, alloc; | 399 | struct resource tmp = *new, avail, alloc; |
| 480 | 400 | ||
| 401 | tmp.flags = new->flags; | ||
| 481 | tmp.start = root->start; | 402 | tmp.start = root->start; |
| 482 | /* | 403 | /* |
| 483 | * Skip past an allocated resource that starts at 0, since the | 404 | * Skip past an allocated resource that starts at 0, since the assignment |
| 484 | * assignment of this->start - 1 to tmp->end below would cause an | 405 | * of this->start - 1 to tmp->end below would cause an underflow. |
| 485 | * underflow. | ||
| 486 | */ | 406 | */ |
| 487 | if (this && this->start == 0) { | 407 | if (this && this->start == 0) { |
| 488 | tmp.start = this->end + 1; | 408 | tmp.start = this->end + 1; |
| 489 | this = this->sibling; | 409 | this = this->sibling; |
| 490 | } | 410 | } |
| 491 | for (;;) { | 411 | for(;;) { |
| 492 | if (this) | 412 | if (this) |
| 493 | tmp.end = this->start - 1; | 413 | tmp.end = this->start - 1; |
| 494 | else | 414 | else |
| 495 | tmp.end = root->end; | 415 | tmp.end = root->end; |
| 496 | 416 | ||
| 497 | resource_clip(&tmp, min, max); | 417 | resource_clip(&tmp, min, max); |
| 418 | arch_remove_reservations(&tmp); | ||
| 498 | 419 | ||
| 499 | /* Check for overflow after ALIGN() */ | 420 | /* Check for overflow after ALIGN() */ |
| 500 | avail = *new; | 421 | avail = *new; |
| @@ -509,10 +430,8 @@ static int find_resource(struct resource *root, struct resource *new, | |||
| 509 | return 0; | 430 | return 0; |
| 510 | } | 431 | } |
| 511 | } | 432 | } |
| 512 | |||
| 513 | if (!this) | 433 | if (!this) |
| 514 | break; | 434 | break; |
| 515 | |||
| 516 | tmp.start = this->end + 1; | 435 | tmp.start = this->end + 1; |
| 517 | this = this->sibling; | 436 | this = this->sibling; |
| 518 | } | 437 | } |
| @@ -545,10 +464,7 @@ int allocate_resource(struct resource *root, struct resource *new, | |||
| 545 | alignf = simple_align_resource; | 464 | alignf = simple_align_resource; |
| 546 | 465 | ||
| 547 | write_lock(&resource_lock); | 466 | write_lock(&resource_lock); |
| 548 | if (resource_alloc_from_bottom) | 467 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); |
| 549 | err = find_resource(root, new, size, min, max, align, alignf, alignf_data); | ||
| 550 | else | ||
| 551 | err = find_resource_from_top(root, new, size, min, max, align, alignf, alignf_data); | ||
| 552 | if (err >= 0 && __request_resource(root, new)) | 468 | if (err >= 0 && __request_resource(root, new)) |
| 553 | err = -EBUSY; | 469 | err = -EBUSY; |
| 554 | write_unlock(&resource_lock); | 470 | write_unlock(&resource_lock); |
