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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/export.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/sched.h> 21 #include <linux/seq_file.h> 22 #include <linux/device.h> 23 #include <linux/pfn.h> 24 #include <linux/mm.h> 25 #include <linux/resource_ext.h> 26 #include <asm/io.h> 27 28 29 struct resource ioport_resource = { 30 .name = "PCI IO", 31 .start = 0, 32 .end = IO_SPACE_LIMIT, 33 .flags = IORESOURCE_IO, 34 }; 35 EXPORT_SYMBOL(ioport_resource); 36 37 struct resource iomem_resource = { 38 .name = "PCI mem", 39 .start = 0, 40 .end = -1, 41 .flags = IORESOURCE_MEM, 42 }; 43 EXPORT_SYMBOL(iomem_resource); 44 45 /* constraints to be met while allocating resources */ 46 struct resource_constraint { 47 resource_size_t min, max, align; 48 resource_size_t (*alignf)(void *, const struct resource *, 49 resource_size_t, resource_size_t); 50 void *alignf_data; 51 }; 52 53 static DEFINE_RWLOCK(resource_lock); 54 55 /* 56 * For memory hotplug, there is no way to free resource entries allocated 57 * by boot mem after the system is up. So for reusing the resource entry 58 * we need to remember the resource. 59 */ 60 static struct resource *bootmem_resource_free; 61 static DEFINE_SPINLOCK(bootmem_resource_lock); 62 63 static struct resource *next_resource(struct resource *p, bool sibling_only) 64 { 65 /* Caller wants to traverse through siblings only */ 66 if (sibling_only) 67 return p->sibling; 68 69 if (p->child) 70 return p->child; 71 while (!p->sibling && p->parent) 72 p = p->parent; 73 return p->sibling; 74 } 75 76 static void *r_next(struct seq_file *m, void *v, loff_t *pos) 77 { 78 struct resource *p = v; 79 (*pos)++; 80 return (void *)next_resource(p, false); 81 } 82 83 #ifdef CONFIG_PROC_FS 84 85 enum { MAX_IORES_LEVEL = 5 }; 86 87 static void *r_start(struct seq_file *m, loff_t *pos) 88 __acquires(resource_lock) 89 { 90 struct resource *p = m->private; 91 loff_t l = 0; 92 read_lock(&resource_lock); 93 for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) 94 ; 95 return p; 96 } 97 98 static void r_stop(struct seq_file *m, void *v) 99 __releases(resource_lock) 100 { 101 read_unlock(&resource_lock); 102 } 103 104 static int r_show(struct seq_file *m, void *v) 105 { 106 struct resource *root = m->private; 107 struct resource *r = v, *p; 108 unsigned long long start, end; 109 int width = root->end < 0x10000 ? 4 : 8; 110 int depth; 111 112 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) 113 if (p->parent == root) 114 break; 115 116 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) { 117 start = r->start; 118 end = r->end; 119 } else { 120 start = end = 0; 121 } 122 123 seq_printf(m, "%*s%0*llx-%0*llx : %s\n", 124 depth * 2, "", 125 width, start, 126 width, end, 127 r->name ? r->name : "<BAD>"); 128 return 0; 129 } 130 131 static const struct seq_operations resource_op = { 132 .start = r_start, 133 .next = r_next, 134 .stop = r_stop, 135 .show = r_show, 136 }; 137 138 static int ioports_open(struct inode *inode, struct file *file) 139 { 140 int res = seq_open(file, &resource_op); 141 if (!res) { 142 struct seq_file *m = file->private_data; 143 m->private = &ioport_resource; 144 } 145 return res; 146 } 147 148 static int iomem_open(struct inode *inode, struct file *file) 149 { 150 int res = seq_open(file, &resource_op); 151 if (!res) { 152 struct seq_file *m = file->private_data; 153 m->private = &iomem_resource; 154 } 155 return res; 156 } 157 158 static const struct file_operations proc_ioports_operations = { 159 .open = ioports_open, 160 .read = seq_read, 161 .llseek = seq_lseek, 162 .release = seq_release, 163 }; 164 165 static const struct file_operations proc_iomem_operations = { 166 .open = iomem_open, 167 .read = seq_read, 168 .llseek = seq_lseek, 169 .release = seq_release, 170 }; 171 172 static int __init ioresources_init(void) 173 { 174 proc_create("ioports", 0, NULL, &proc_ioports_operations); 175 proc_create("iomem", 0, NULL, &proc_iomem_operations); 176 return 0; 177 } 178 __initcall(ioresources_init); 179 180 #endif /* CONFIG_PROC_FS */ 181 182 static void free_resource(struct resource *res) 183 { 184 if (!res) 185 return; 186 187 if (!PageSlab(virt_to_head_page(res))) { 188 spin_lock(&bootmem_resource_lock); 189 res->sibling = bootmem_resource_free; 190 bootmem_resource_free = res; 191 spin_unlock(&bootmem_resource_lock); 192 } else { 193 kfree(res); 194 } 195 } 196 197 static struct resource *alloc_resource(gfp_t flags) 198 { 199 struct resource *res = NULL; 200 201 spin_lock(&bootmem_resource_lock); 202 if (bootmem_resource_free) { 203 res = bootmem_resource_free; 204 bootmem_resource_free = res->sibling; 205 } 206 spin_unlock(&bootmem_resource_lock); 207 208 if (res) 209 memset(res, 0, sizeof(struct resource)); 210 else 211 res = kzalloc(sizeof(struct resource), flags); 212 213 return res; 214 } 215 216 /* Return the conflict entry if you can't request it */ 217 static struct resource * __request_resource(struct resource *root, struct resource *new) 218 { 219 resource_size_t start = new->start; 220 resource_size_t end = new->end; 221 struct resource *tmp, **p; 222 223 if (end < start) 224 return root; 225 if (start < root->start) 226 return root; 227 if (end > root->end) 228 return root; 229 p = &root->child; 230 for (;;) { 231 tmp = *p; 232 if (!tmp || tmp->start > end) { 233 new->sibling = tmp; 234 *p = new; 235 new->parent = root; 236 return NULL; 237 } 238 p = &tmp->sibling; 239 if (tmp->end < start) 240 continue; 241 return tmp; 242 } 243 } 244 245 static int __release_resource(struct resource *old, bool release_child) 246 { 247 struct resource *tmp, **p, *chd; 248 249 p = &old->parent->child; 250 for (;;) { 251 tmp = *p; 252 if (!tmp) 253 break; 254 if (tmp == old) { 255 if (release_child || !(tmp->child)) { 256 *p = tmp->sibling; 257 } else { 258 for (chd = tmp->child;; chd = chd->sibling) { 259 chd->parent = tmp->parent; 260 if (!(chd->sibling)) 261 break; 262 } 263 *p = tmp->child; 264 chd->sibling = tmp->sibling; 265 } 266 old->parent = NULL; 267 return 0; 268 } 269 p = &tmp->sibling; 270 } 271 return -EINVAL; 272 } 273 274 static void __release_child_resources(struct resource *r) 275 { 276 struct resource *tmp, *p; 277 resource_size_t size; 278 279 p = r->child; 280 r->child = NULL; 281 while (p) { 282 tmp = p; 283 p = p->sibling; 284 285 tmp->parent = NULL; 286 tmp->sibling = NULL; 287 __release_child_resources(tmp); 288 289 printk(KERN_DEBUG "release child resource %pR\n", tmp); 290 /* need to restore size, and keep flags */ 291 size = resource_size(tmp); 292 tmp->start = 0; 293 tmp->end = size - 1; 294 } 295 } 296 297 void release_child_resources(struct resource *r) 298 { 299 write_lock(&resource_lock); 300 __release_child_resources(r); 301 write_unlock(&resource_lock); 302 } 303 304 /** 305 * request_resource_conflict - request and reserve an I/O or memory resource 306 * @root: root resource descriptor 307 * @new: resource descriptor desired by caller 308 * 309 * Returns 0 for success, conflict resource on error. 310 */ 311 struct resource *request_resource_conflict(struct resource *root, struct resource *new) 312 { 313 struct resource *conflict; 314 315 write_lock(&resource_lock); 316 conflict = __request_resource(root, new); 317 write_unlock(&resource_lock); 318 return conflict; 319 } 320 321 /** 322 * request_resource - request and reserve an I/O or memory resource 323 * @root: root resource descriptor 324 * @new: resource descriptor desired by caller 325 * 326 * Returns 0 for success, negative error code on error. 327 */ 328 int request_resource(struct resource *root, struct resource *new) 329 { 330 struct resource *conflict; 331 332 conflict = request_resource_conflict(root, new); 333 return conflict ? -EBUSY : 0; 334 } 335 336 EXPORT_SYMBOL(request_resource); 337 338 /** 339 * release_resource - release a previously reserved resource 340 * @old: resource pointer 341 */ 342 int release_resource(struct resource *old) 343 { 344 int retval; 345 346 write_lock(&resource_lock); 347 retval = __release_resource(old, true); 348 write_unlock(&resource_lock); 349 return retval; 350 } 351 352 EXPORT_SYMBOL(release_resource); 353 354 /* 355 * Finds the lowest iomem resource existing within [res->start.res->end). 356 * The caller must specify res->start, res->end, res->flags, and optionally 357 * desc. If found, returns 0, res is overwritten, if not found, returns -1. 358 * This function walks the whole tree and not just first level children until 359 * and unless first_level_children_only is true. 360 */ 361 static int find_next_iomem_res(struct resource *res, unsigned long desc, 362 bool first_level_children_only) 363 { 364 resource_size_t start, end; 365 struct resource *p; 366 bool sibling_only = false; 367 368 BUG_ON(!res); 369 370 start = res->start; 371 end = res->end; 372 BUG_ON(start >= end); 373 374 if (first_level_children_only) 375 sibling_only = true; 376 377 read_lock(&resource_lock); 378 379 for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) { 380 if ((p->flags & res->flags) != res->flags) 381 continue; 382 if ((desc != IORES_DESC_NONE) && (desc != p->desc)) 383 continue; 384 if (p->start > end) { 385 p = NULL; 386 break; 387 } 388 if ((p->end >= start) && (p->start < end)) 389 break; 390 } 391 392 read_unlock(&resource_lock); 393 if (!p) 394 return -1; 395 /* copy data */ 396 if (res->start < p->start) 397 res->start = p->start; 398 if (res->end > p->end) 399 res->end = p->end; 400 res->flags = p->flags; 401 res->desc = p->desc; 402 return 0; 403 } 404 405 static int __walk_iomem_res_desc(struct resource *res, unsigned long desc, 406 bool first_level_children_only, 407 void *arg, 408 int (*func)(struct resource *, void *)) 409 { 410 u64 orig_end = res->end; 411 int ret = -1; 412 413 while ((res->start < res->end) && 414 !find_next_iomem_res(res, desc, first_level_children_only)) { 415 ret = (*func)(res, arg); 416 if (ret) 417 break; 418 419 res->start = res->end + 1; 420 res->end = orig_end; 421 } 422 423 return ret; 424 } 425 426 /* 427 * Walks through iomem resources and calls func() with matching resource 428 * ranges. This walks through whole tree and not just first level children. 429 * All the memory ranges which overlap start,end and also match flags and 430 * desc are valid candidates. 431 * 432 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check. 433 * @flags: I/O resource flags 434 * @start: start addr 435 * @end: end addr 436 * 437 * NOTE: For a new descriptor search, define a new IORES_DESC in 438 * <linux/ioport.h> and set it in 'desc' of a target resource entry. 439 */ 440 int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, 441 u64 end, void *arg, int (*func)(struct resource *, void *)) 442 { 443 struct resource res; 444 445 res.start = start; 446 res.end = end; 447 res.flags = flags; 448 449 return __walk_iomem_res_desc(&res, desc, false, arg, func); 450 } 451 452 /* 453 * This function calls the @func callback against all memory ranges of type 454 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. 455 * Now, this function is only for System RAM, it deals with full ranges and 456 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate 457 * ranges. 458 */ 459 int walk_system_ram_res(u64 start, u64 end, void *arg, 460 int (*func)(struct resource *, void *)) 461 { 462 struct resource res; 463 464 res.start = start; 465 res.end = end; 466 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 467 468 return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true, 469 arg, func); 470 } 471 472 /* 473 * This function calls the @func callback against all memory ranges, which 474 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. 475 */ 476 int walk_mem_res(u64 start, u64 end, void *arg, 477 int (*func)(struct resource *, void *)) 478 { 479 struct resource res; 480 481 res.start = start; 482 res.end = end; 483 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; 484 485 return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true, 486 arg, func); 487 } 488 489 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) 490 491 /* 492 * This function calls the @func callback against all memory ranges of type 493 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. 494 * It is to be used only for System RAM. 495 */ 496 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, 497 void *arg, int (*func)(unsigned long, unsigned long, void *)) 498 { 499 struct resource res; 500 unsigned long pfn, end_pfn; 501 u64 orig_end; 502 int ret = -1; 503 504 res.start = (u64) start_pfn << PAGE_SHIFT; 505 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; 506 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 507 orig_end = res.end; 508 while ((res.start < res.end) && 509 (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) { 510 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; 511 end_pfn = (res.end + 1) >> PAGE_SHIFT; 512 if (end_pfn > pfn) 513 ret = (*func)(pfn, end_pfn - pfn, arg); 514 if (ret) 515 break; 516 res.start = res.end + 1; 517 res.end = orig_end; 518 } 519 return ret; 520 } 521 522 #endif 523 524 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) 525 { 526 return 1; 527 } 528 529 /* 530 * This generic page_is_ram() returns true if specified address is 531 * registered as System RAM in iomem_resource list. 532 */ 533 int __weak page_is_ram(unsigned long pfn) 534 { 535 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; 536 } 537 EXPORT_SYMBOL_GPL(page_is_ram); 538 539 /** 540 * region_intersects() - determine intersection of region with known resources 541 * @start: region start address 542 * @size: size of region 543 * @flags: flags of resource (in iomem_resource) 544 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE 545 * 546 * Check if the specified region partially overlaps or fully eclipses a 547 * resource identified by @flags and @desc (optional with IORES_DESC_NONE). 548 * Return REGION_DISJOINT if the region does not overlap @flags/@desc, 549 * return REGION_MIXED if the region overlaps @flags/@desc and another 550 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc 551 * and no other defined resource. Note that REGION_INTERSECTS is also 552 * returned in the case when the specified region overlaps RAM and undefined 553 * memory holes. 554 * 555 * region_intersect() is used by memory remapping functions to ensure 556 * the user is not remapping RAM and is a vast speed up over walking 557 * through the resource table page by page. 558 */ 559 int region_intersects(resource_size_t start, size_t size, unsigned long flags, 560 unsigned long desc) 561 { 562 resource_size_t end = start + size - 1; 563 int type = 0; int other = 0; 564 struct resource *p; 565 566 read_lock(&resource_lock); 567 for (p = iomem_resource.child; p ; p = p->sibling) { 568 bool is_type = (((p->flags & flags) == flags) && 569 ((desc == IORES_DESC_NONE) || 570 (desc == p->desc))); 571 572 if (start >= p->start && start <= p->end) 573 is_type ? type++ : other++; 574 if (end >= p->start && end <= p->end) 575 is_type ? type++ : other++; 576 if (p->start >= start && p->end <= end) 577 is_type ? type++ : other++; 578 } 579 read_unlock(&resource_lock); 580 581 if (other == 0) 582 return type ? REGION_INTERSECTS : REGION_DISJOINT; 583 584 if (type) 585 return REGION_MIXED; 586 587 return REGION_DISJOINT; 588 } 589 EXPORT_SYMBOL_GPL(region_intersects); 590 591 void __weak arch_remove_reservations(struct resource *avail) 592 { 593 } 594 595 static resource_size_t simple_align_resource(void *data, 596 const struct resource *avail, 597 resource_size_t size, 598 resource_size_t align) 599 { 600 return avail->start; 601 } 602 603 static void resource_clip(struct resource *res, resource_size_t min, 604 resource_size_t max) 605 { 606 if (res->start < min) 607 res->start = min; 608 if (res->end > max) 609 res->end = max; 610 } 611 612 /* 613 * Find empty slot in the resource tree with the given range and 614 * alignment constraints 615 */ 616 static int __find_resource(struct resource *root, struct resource *old, 617 struct resource *new, 618 resource_size_t size, 619 struct resource_constraint *constraint) 620 { 621 struct resource *this = root->child; 622 struct resource tmp = *new, avail, alloc; 623 624 tmp.start = root->start; 625 /* 626 * Skip past an allocated resource that starts at 0, since the assignment 627 * of this->start - 1 to tmp->end below would cause an underflow. 628 */ 629 if (this && this->start == root->start) { 630 tmp.start = (this == old) ? old->start : this->end + 1; 631 this = this->sibling; 632 } 633 for(;;) { 634 if (this) 635 tmp.end = (this == old) ? this->end : this->start - 1; 636 else 637 tmp.end = root->end; 638 639 if (tmp.end < tmp.start) 640 goto next; 641 642 resource_clip(&tmp, constraint->min, constraint->max); 643 arch_remove_reservations(&tmp); 644 645 /* Check for overflow after ALIGN() */ 646 avail.start = ALIGN(tmp.start, constraint->align); 647 avail.end = tmp.end; 648 avail.flags = new->flags & ~IORESOURCE_UNSET; 649 if (avail.start >= tmp.start) { 650 alloc.flags = avail.flags; 651 alloc.start = constraint->alignf(constraint->alignf_data, &avail, 652 size, constraint->align); 653 alloc.end = alloc.start + size - 1; 654 if (resource_contains(&avail, &alloc)) { 655 new->start = alloc.start; 656 new->end = alloc.end; 657 return 0; 658 } 659 } 660 661 next: if (!this || this->end == root->end) 662 break; 663 664 if (this != old) 665 tmp.start = this->end + 1; 666 this = this->sibling; 667 } 668 return -EBUSY; 669 } 670 671 /* 672 * Find empty slot in the resource tree given range and alignment. 673 */ 674 static int find_resource(struct resource *root, struct resource *new, 675 resource_size_t size, 676 struct resource_constraint *constraint) 677 { 678 return __find_resource(root, NULL, new, size, constraint); 679 } 680 681 /** 682 * reallocate_resource - allocate a slot in the resource tree given range & alignment. 683 * The resource will be relocated if the new size cannot be reallocated in the 684 * current location. 685 * 686 * @root: root resource descriptor 687 * @old: resource descriptor desired by caller 688 * @newsize: new size of the resource descriptor 689 * @constraint: the size and alignment constraints to be met. 690 */ 691 static int reallocate_resource(struct resource *root, struct resource *old, 692 resource_size_t newsize, 693 struct resource_constraint *constraint) 694 { 695 int err=0; 696 struct resource new = *old; 697 struct resource *conflict; 698 699 write_lock(&resource_lock); 700 701 if ((err = __find_resource(root, old, &new, newsize, constraint))) 702 goto out; 703 704 if (resource_contains(&new, old)) { 705 old->start = new.start; 706 old->end = new.end; 707 goto out; 708 } 709 710 if (old->child) { 711 err = -EBUSY; 712 goto out; 713 } 714 715 if (resource_contains(old, &new)) { 716 old->start = new.start; 717 old->end = new.end; 718 } else { 719 __release_resource(old, true); 720 *old = new; 721 conflict = __request_resource(root, old); 722 BUG_ON(conflict); 723 } 724 out: 725 write_unlock(&resource_lock); 726 return err; 727 } 728 729 730 /** 731 * allocate_resource - allocate empty slot in the resource tree given range & alignment. 732 * The resource will be reallocated with a new size if it was already allocated 733 * @root: root resource descriptor 734 * @new: resource descriptor desired by caller 735 * @size: requested resource region size 736 * @min: minimum boundary to allocate 737 * @max: maximum boundary to allocate 738 * @align: alignment requested, in bytes 739 * @alignf: alignment function, optional, called if not NULL 740 * @alignf_data: arbitrary data to pass to the @alignf function 741 */ 742 int allocate_resource(struct resource *root, struct resource *new, 743 resource_size_t size, resource_size_t min, 744 resource_size_t max, resource_size_t align, 745 resource_size_t (*alignf)(void *, 746 const struct resource *, 747 resource_size_t, 748 resource_size_t), 749 void *alignf_data) 750 { 751 int err; 752 struct resource_constraint constraint; 753 754 if (!alignf) 755 alignf = simple_align_resource; 756 757 constraint.min = min; 758 constraint.max = max; 759 constraint.align = align; 760 constraint.alignf = alignf; 761 constraint.alignf_data = alignf_data; 762 763 if ( new->parent ) { 764 /* resource is already allocated, try reallocating with 765 the new constraints */ 766 return reallocate_resource(root, new, size, &constraint); 767 } 768 769 write_lock(&resource_lock); 770 err = find_resource(root, new, size, &constraint); 771 if (err >= 0 && __request_resource(root, new)) 772 err = -EBUSY; 773 write_unlock(&resource_lock); 774 return err; 775 } 776 777 EXPORT_SYMBOL(allocate_resource); 778 779 /** 780 * lookup_resource - find an existing resource by a resource start address 781 * @root: root resource descriptor 782 * @start: resource start address 783 * 784 * Returns a pointer to the resource if found, NULL otherwise 785 */ 786 struct resource *lookup_resource(struct resource *root, resource_size_t start) 787 { 788 struct resource *res; 789 790 read_lock(&resource_lock); 791 for (res = root->child; res; res = res->sibling) { 792 if (res->start == start) 793 break; 794 } 795 read_unlock(&resource_lock); 796 797 return res; 798 } 799 800 /* 801 * Insert a resource into the resource tree. If successful, return NULL, 802 * otherwise return the conflicting resource (compare to __request_resource()) 803 */ 804 static struct resource * __insert_resource(struct resource *parent, struct resource *new) 805 { 806 struct resource *first, *next; 807 808 for (;; parent = first) { 809 first = __request_resource(parent, new); 810 if (!first) 811 return first; 812 813 if (first == parent) 814 return first; 815 if (WARN_ON(first == new)) /* duplicated insertion */ 816 return first; 817 818 if ((first->start > new->start) || (first->end < new->end)) 819 break; 820 if ((first->start == new->start) && (first->end == new->end)) 821 break; 822 } 823 824 for (next = first; ; next = next->sibling) { 825 /* Partial overlap? Bad, and unfixable */ 826 if (next->start < new->start || next->end > new->end) 827 return next; 828 if (!next->sibling) 829 break; 830 if (next->sibling->start > new->end) 831 break; 832 } 833 834 new->parent = parent; 835 new->sibling = next->sibling; 836 new->child = first; 837 838 next->sibling = NULL; 839 for (next = first; next; next = next->sibling) 840 next->parent = new; 841 842 if (parent->child == first) { 843 parent->child = new; 844 } else { 845 next = parent->child; 846 while (next->sibling != first) 847 next = next->sibling; 848 next->sibling = new; 849 } 850 return NULL; 851 } 852 853 /** 854 * insert_resource_conflict - Inserts resource in the resource tree 855 * @parent: parent of the new resource 856 * @new: new resource to insert 857 * 858 * Returns 0 on success, conflict resource if the resource can't be inserted. 859 * 860 * This function is equivalent to request_resource_conflict when no conflict 861 * happens. If a conflict happens, and the conflicting resources 862 * entirely fit within the range of the new resource, then the new 863 * resource is inserted and the conflicting resources become children of 864 * the new resource. 865 * 866 * This function is intended for producers of resources, such as FW modules 867 * and bus drivers. 868 */ 869 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) 870 { 871 struct resource *conflict; 872 873 write_lock(&resource_lock); 874 conflict = __insert_resource(parent, new); 875 write_unlock(&resource_lock); 876 return conflict; 877 } 878 879 /** 880 * insert_resource - Inserts a resource in the resource tree 881 * @parent: parent of the new resource 882 * @new: new resource to insert 883 * 884 * Returns 0 on success, -EBUSY if the resource can't be inserted. 885 * 886 * This function is intended for producers of resources, such as FW modules 887 * and bus drivers. 888 */ 889 int insert_resource(struct resource *parent, struct resource *new) 890 { 891 struct resource *conflict; 892 893 conflict = insert_resource_conflict(parent, new); 894 return conflict ? -EBUSY : 0; 895 } 896 EXPORT_SYMBOL_GPL(insert_resource); 897 898 /** 899 * insert_resource_expand_to_fit - Insert a resource into the resource tree 900 * @root: root resource descriptor 901 * @new: new resource to insert 902 * 903 * Insert a resource into the resource tree, possibly expanding it in order 904 * to make it encompass any conflicting resources. 905 */ 906 void insert_resource_expand_to_fit(struct resource *root, struct resource *new) 907 { 908 if (new->parent) 909 return; 910 911 write_lock(&resource_lock); 912 for (;;) { 913 struct resource *conflict; 914 915 conflict = __insert_resource(root, new); 916 if (!conflict) 917 break; 918 if (conflict == root) 919 break; 920 921 /* Ok, expand resource to cover the conflict, then try again .. */ 922 if (conflict->start < new->start) 923 new->start = conflict->start; 924 if (conflict->end > new->end) 925 new->end = conflict->end; 926 927 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); 928 } 929 write_unlock(&resource_lock); 930 } 931 932 /** 933 * remove_resource - Remove a resource in the resource tree 934 * @old: resource to remove 935 * 936 * Returns 0 on success, -EINVAL if the resource is not valid. 937 * 938 * This function removes a resource previously inserted by insert_resource() 939 * or insert_resource_conflict(), and moves the children (if any) up to 940 * where they were before. insert_resource() and insert_resource_conflict() 941 * insert a new resource, and move any conflicting resources down to the 942 * children of the new resource. 943 * 944 * insert_resource(), insert_resource_conflict() and remove_resource() are 945 * intended for producers of resources, such as FW modules and bus drivers. 946 */ 947 int remove_resource(struct resource *old) 948 { 949 int retval; 950 951 write_lock(&resource_lock); 952 retval = __release_resource(old, false); 953 write_unlock(&resource_lock); 954 return retval; 955 } 956 EXPORT_SYMBOL_GPL(remove_resource); 957 958 static int __adjust_resource(struct resource *res, resource_size_t start, 959 resource_size_t size) 960 { 961 struct resource *tmp, *parent = res->parent; 962 resource_size_t end = start + size - 1; 963 int result = -EBUSY; 964 965 if (!parent) 966 goto skip; 967 968 if ((start < parent->start) || (end > parent->end)) 969 goto out; 970 971 if (res->sibling && (res->sibling->start <= end)) 972 goto out; 973 974 tmp = parent->child; 975 if (tmp != res) { 976 while (tmp->sibling != res) 977 tmp = tmp->sibling; 978 if (start <= tmp->end) 979 goto out; 980 } 981 982 skip: 983 for (tmp = res->child; tmp; tmp = tmp->sibling) 984 if ((tmp->start < start) || (tmp->end > end)) 985 goto out; 986 987 res->start = start; 988 res->end = end; 989 result = 0; 990 991 out: 992 return result; 993 } 994 995 /** 996 * adjust_resource - modify a resource's start and size 997 * @res: resource to modify 998 * @start: new start value 999 * @size: new size 1000 * 1001 * Given an existing resource, change its start and size to match the 1002 * arguments. Returns 0 on success, -EBUSY if it can't fit. 1003 * Existing children of the resource are assumed to be immutable. 1004 */ 1005 int adjust_resource(struct resource *res, resource_size_t start, 1006 resource_size_t size) 1007 { 1008 int result; 1009 1010 write_lock(&resource_lock); 1011 result = __adjust_resource(res, start, size); 1012 write_unlock(&resource_lock); 1013 return result; 1014 } 1015 EXPORT_SYMBOL(adjust_resource); 1016 1017 static void __init __reserve_region_with_split(struct resource *root, 1018 resource_size_t start, resource_size_t end, 1019 const char *name) 1020 { 1021 struct resource *parent = root; 1022 struct resource *conflict; 1023 struct resource *res = alloc_resource(GFP_ATOMIC); 1024 struct resource *next_res = NULL; 1025 int type = resource_type(root); 1026 1027 if (!res) 1028 return; 1029 1030 res->name = name; 1031 res->start = start; 1032 res->end = end; 1033 res->flags = type | IORESOURCE_BUSY; 1034 res->desc = IORES_DESC_NONE; 1035 1036 while (1) { 1037 1038 conflict = __request_resource(parent, res); 1039 if (!conflict) { 1040 if (!next_res) 1041 break; 1042 res = next_res; 1043 next_res = NULL; 1044 continue; 1045 } 1046 1047 /* conflict covered whole area */ 1048 if (conflict->start <= res->start && 1049 conflict->end >= res->end) { 1050 free_resource(res); 1051 WARN_ON(next_res); 1052 break; 1053 } 1054 1055 /* failed, split and try again */ 1056 if (conflict->start > res->start) { 1057 end = res->end; 1058 res->end = conflict->start - 1; 1059 if (conflict->end < end) { 1060 next_res = alloc_resource(GFP_ATOMIC); 1061 if (!next_res) { 1062 free_resource(res); 1063 break; 1064 } 1065 next_res->name = name; 1066 next_res->start = conflict->end + 1; 1067 next_res->end = end; 1068 next_res->flags = type | IORESOURCE_BUSY; 1069 next_res->desc = IORES_DESC_NONE; 1070 } 1071 } else { 1072 res->start = conflict->end + 1; 1073 } 1074 } 1075 1076 } 1077 1078 void __init reserve_region_with_split(struct resource *root, 1079 resource_size_t start, resource_size_t end, 1080 const char *name) 1081 { 1082 int abort = 0; 1083 1084 write_lock(&resource_lock); 1085 if (root->start > start || root->end < end) { 1086 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", 1087 (unsigned long long)start, (unsigned long long)end, 1088 root); 1089 if (start > root->end || end < root->start) 1090 abort = 1; 1091 else { 1092 if (end > root->end) 1093 end = root->end; 1094 if (start < root->start) 1095 start = root->start; 1096 pr_err("fixing request to [0x%llx-0x%llx]\n", 1097 (unsigned long long)start, 1098 (unsigned long long)end); 1099 } 1100 dump_stack(); 1101 } 1102 if (!abort) 1103 __reserve_region_with_split(root, start, end, name); 1104 write_unlock(&resource_lock); 1105 } 1106 1107 /** 1108 * resource_alignment - calculate resource's alignment 1109 * @res: resource pointer 1110 * 1111 * Returns alignment on success, 0 (invalid alignment) on failure. 1112 */ 1113 resource_size_t resource_alignment(struct resource *res) 1114 { 1115 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { 1116 case IORESOURCE_SIZEALIGN: 1117 return resource_size(res); 1118 case IORESOURCE_STARTALIGN: 1119 return res->start; 1120 default: 1121 return 0; 1122 } 1123 } 1124 1125 /* 1126 * This is compatibility stuff for IO resources. 1127 * 1128 * Note how this, unlike the above, knows about 1129 * the IO flag meanings (busy etc). 1130 * 1131 * request_region creates a new busy region. 1132 * 1133 * release_region releases a matching busy region. 1134 */ 1135 1136 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); 1137 1138 /** 1139 * __request_region - create a new busy resource region 1140 * @parent: parent resource descriptor 1141 * @start: resource start address 1142 * @n: resource region size 1143 * @name: reserving caller's ID string 1144 * @flags: IO resource flags 1145 */ 1146 struct resource * __request_region(struct resource *parent, 1147 resource_size_t start, resource_size_t n, 1148 const char *name, int flags) 1149 { 1150 DECLARE_WAITQUEUE(wait, current); 1151 struct resource *res = alloc_resource(GFP_KERNEL); 1152 1153 if (!res) 1154 return NULL; 1155 1156 res->name = name; 1157 res->start = start; 1158 res->end = start + n - 1; 1159 1160 write_lock(&resource_lock); 1161 1162 for (;;) { 1163 struct resource *conflict; 1164 1165 res->flags = resource_type(parent) | resource_ext_type(parent); 1166 res->flags |= IORESOURCE_BUSY | flags; 1167 res->desc = parent->desc; 1168 1169 conflict = __request_resource(parent, res); 1170 if (!conflict) 1171 break; 1172 if (conflict != parent) { 1173 if (!(conflict->flags & IORESOURCE_BUSY)) { 1174 parent = conflict; 1175 continue; 1176 } 1177 } 1178 if (conflict->flags & flags & IORESOURCE_MUXED) { 1179 add_wait_queue(&muxed_resource_wait, &wait); 1180 write_unlock(&resource_lock); 1181 set_current_state(TASK_UNINTERRUPTIBLE); 1182 schedule(); 1183 remove_wait_queue(&muxed_resource_wait, &wait); 1184 write_lock(&resource_lock); 1185 continue; 1186 } 1187 /* Uhhuh, that didn't work out.. */ 1188 free_resource(res); 1189 res = NULL; 1190 break; 1191 } 1192 write_unlock(&resource_lock); 1193 return res; 1194 } 1195 EXPORT_SYMBOL(__request_region); 1196 1197 /** 1198 * __release_region - release a previously reserved resource region 1199 * @parent: parent resource descriptor 1200 * @start: resource start address 1201 * @n: resource region size 1202 * 1203 * The described resource region must match a currently busy region. 1204 */ 1205 void __release_region(struct resource *parent, resource_size_t start, 1206 resource_size_t n) 1207 { 1208 struct resource **p; 1209 resource_size_t end; 1210 1211 p = &parent->child; 1212 end = start + n - 1; 1213 1214 write_lock(&resource_lock); 1215 1216 for (;;) { 1217 struct resource *res = *p; 1218 1219 if (!res) 1220 break; 1221 if (res->start <= start && res->end >= end) { 1222 if (!(res->flags & IORESOURCE_BUSY)) { 1223 p = &res->child; 1224 continue; 1225 } 1226 if (res->start != start || res->end != end) 1227 break; 1228 *p = res->sibling; 1229 write_unlock(&resource_lock); 1230 if (res->flags & IORESOURCE_MUXED) 1231 wake_up(&muxed_resource_wait); 1232 free_resource(res); 1233 return; 1234 } 1235 p = &res->sibling; 1236 } 1237 1238 write_unlock(&resource_lock); 1239 1240 printk(KERN_WARNING "Trying to free nonexistent resource " 1241 "<%016llx-%016llx>\n", (unsigned long long)start, 1242 (unsigned long long)end); 1243 } 1244 EXPORT_SYMBOL(__release_region); 1245 1246 #ifdef CONFIG_MEMORY_HOTREMOVE 1247 /** 1248 * release_mem_region_adjustable - release a previously reserved memory region 1249 * @parent: parent resource descriptor 1250 * @start: resource start address 1251 * @size: resource region size 1252 * 1253 * This interface is intended for memory hot-delete. The requested region 1254 * is released from a currently busy memory resource. The requested region 1255 * must either match exactly or fit into a single busy resource entry. In 1256 * the latter case, the remaining resource is adjusted accordingly. 1257 * Existing children of the busy memory resource must be immutable in the 1258 * request. 1259 * 1260 * Note: 1261 * - Additional release conditions, such as overlapping region, can be 1262 * supported after they are confirmed as valid cases. 1263 * - When a busy memory resource gets split into two entries, the code 1264 * assumes that all children remain in the lower address entry for 1265 * simplicity. Enhance this logic when necessary. 1266 */ 1267 int release_mem_region_adjustable(struct resource *parent, 1268 resource_size_t start, resource_size_t size) 1269 { 1270 struct resource **p; 1271 struct resource *res; 1272 struct resource *new_res; 1273 resource_size_t end; 1274 int ret = -EINVAL; 1275 1276 end = start + size - 1; 1277 if ((start < parent->start) || (end > parent->end)) 1278 return ret; 1279 1280 /* The alloc_resource() result gets checked later */ 1281 new_res = alloc_resource(GFP_KERNEL); 1282 1283 p = &parent->child; 1284 write_lock(&resource_lock); 1285 1286 while ((res = *p)) { 1287 if (res->start >= end) 1288 break; 1289 1290 /* look for the next resource if it does not fit into */ 1291 if (res->start > start || res->end < end) { 1292 p = &res->sibling; 1293 continue; 1294 } 1295 1296 if (!(res->flags & IORESOURCE_MEM)) 1297 break; 1298 1299 if (!(res->flags & IORESOURCE_BUSY)) { 1300 p = &res->child; 1301 continue; 1302 } 1303 1304 /* found the target resource; let's adjust accordingly */ 1305 if (res->start == start && res->end == end) { 1306 /* free the whole entry */ 1307 *p = res->sibling; 1308 free_resource(res); 1309 ret = 0; 1310 } else if (res->start == start && res->end != end) { 1311 /* adjust the start */ 1312 ret = __adjust_resource(res, end + 1, 1313 res->end - end); 1314 } else if (res->start != start && res->end == end) { 1315 /* adjust the end */ 1316 ret = __adjust_resource(res, res->start, 1317 start - res->start); 1318 } else { 1319 /* split into two entries */ 1320 if (!new_res) { 1321 ret = -ENOMEM; 1322 break; 1323 } 1324 new_res->name = res->name; 1325 new_res->start = end + 1; 1326 new_res->end = res->end; 1327 new_res->flags = res->flags; 1328 new_res->desc = res->desc; 1329 new_res->parent = res->parent; 1330 new_res->sibling = res->sibling; 1331 new_res->child = NULL; 1332 1333 ret = __adjust_resource(res, res->start, 1334 start - res->start); 1335 if (ret) 1336 break; 1337 res->sibling = new_res; 1338 new_res = NULL; 1339 } 1340 1341 break; 1342 } 1343 1344 write_unlock(&resource_lock); 1345 free_resource(new_res); 1346 return ret; 1347 } 1348 #endif /* CONFIG_MEMORY_HOTREMOVE */ 1349 1350 /* 1351 * Managed region resource 1352 */ 1353 static void devm_resource_release(struct device *dev, void *ptr) 1354 { 1355 struct resource **r = ptr; 1356 1357 release_resource(*r); 1358 } 1359 1360 /** 1361 * devm_request_resource() - request and reserve an I/O or memory resource 1362 * @dev: device for which to request the resource 1363 * @root: root of the resource tree from which to request the resource 1364 * @new: descriptor of the resource to request 1365 * 1366 * This is a device-managed version of request_resource(). There is usually 1367 * no need to release resources requested by this function explicitly since 1368 * that will be taken care of when the device is unbound from its driver. 1369 * If for some reason the resource needs to be released explicitly, because 1370 * of ordering issues for example, drivers must call devm_release_resource() 1371 * rather than the regular release_resource(). 1372 * 1373 * When a conflict is detected between any existing resources and the newly 1374 * requested resource, an error message will be printed. 1375 * 1376 * Returns 0 on success or a negative error code on failure. 1377 */ 1378 int devm_request_resource(struct device *dev, struct resource *root, 1379 struct resource *new) 1380 { 1381 struct resource *conflict, **ptr; 1382 1383 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); 1384 if (!ptr) 1385 return -ENOMEM; 1386 1387 *ptr = new; 1388 1389 conflict = request_resource_conflict(root, new); 1390 if (conflict) { 1391 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n", 1392 new, conflict->name, conflict); 1393 devres_free(ptr); 1394 return -EBUSY; 1395 } 1396 1397 devres_add(dev, ptr); 1398 return 0; 1399 } 1400 EXPORT_SYMBOL(devm_request_resource); 1401 1402 static int devm_resource_match(struct device *dev, void *res, void *data) 1403 { 1404 struct resource **ptr = res; 1405 1406 return *ptr == data; 1407 } 1408 1409 /** 1410 * devm_release_resource() - release a previously requested resource 1411 * @dev: device for which to release the resource 1412 * @new: descriptor of the resource to release 1413 * 1414 * Releases a resource previously requested using devm_request_resource(). 1415 */ 1416 void devm_release_resource(struct device *dev, struct resource *new) 1417 { 1418 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, 1419 new)); 1420 } 1421 EXPORT_SYMBOL(devm_release_resource); 1422 1423 struct region_devres { 1424 struct resource *parent; 1425 resource_size_t start; 1426 resource_size_t n; 1427 }; 1428 1429 static void devm_region_release(struct device *dev, void *res) 1430 { 1431 struct region_devres *this = res; 1432 1433 __release_region(this->parent, this->start, this->n); 1434 } 1435 1436 static int devm_region_match(struct device *dev, void *res, void *match_data) 1437 { 1438 struct region_devres *this = res, *match = match_data; 1439 1440 return this->parent == match->parent && 1441 this->start == match->start && this->n == match->n; 1442 } 1443 1444 struct resource * __devm_request_region(struct device *dev, 1445 struct resource *parent, resource_size_t start, 1446 resource_size_t n, const char *name) 1447 { 1448 struct region_devres *dr = NULL; 1449 struct resource *res; 1450 1451 dr = devres_alloc(devm_region_release, sizeof(struct region_devres), 1452 GFP_KERNEL); 1453 if (!dr) 1454 return NULL; 1455 1456 dr->parent = parent; 1457 dr->start = start; 1458 dr->n = n; 1459 1460 res = __request_region(parent, start, n, name, 0); 1461 if (res) 1462 devres_add(dev, dr); 1463 else 1464 devres_free(dr); 1465 1466 return res; 1467 } 1468 EXPORT_SYMBOL(__devm_request_region); 1469 1470 void __devm_release_region(struct device *dev, struct resource *parent, 1471 resource_size_t start, resource_size_t n) 1472 { 1473 struct region_devres match_data = { parent, start, n }; 1474 1475 __release_region(parent, start, n); 1476 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, 1477 &match_data)); 1478 } 1479 EXPORT_SYMBOL(__devm_release_region); 1480 1481 /* 1482 * Reserve I/O ports or memory based on "reserve=" kernel parameter. 1483 */ 1484 #define MAXRESERVE 4 1485 static int __init reserve_setup(char *str) 1486 { 1487 static int reserved; 1488 static struct resource reserve[MAXRESERVE]; 1489 1490 for (;;) { 1491 unsigned int io_start, io_num; 1492 int x = reserved; 1493 struct resource *parent; 1494 1495 if (get_option(&str, &io_start) != 2) 1496 break; 1497 if (get_option(&str, &io_num) == 0) 1498 break; 1499 if (x < MAXRESERVE) { 1500 struct resource *res = reserve + x; 1501 1502 /* 1503 * If the region starts below 0x10000, we assume it's 1504 * I/O port space; otherwise assume it's memory. 1505 */ 1506 if (io_start < 0x10000) { 1507 res->flags = IORESOURCE_IO; 1508 parent = &ioport_resource; 1509 } else { 1510 res->flags = IORESOURCE_MEM; 1511 parent = &iomem_resource; 1512 } 1513 res->name = "reserved"; 1514 res->start = io_start; 1515 res->end = io_start + io_num - 1; 1516 res->flags |= IORESOURCE_BUSY; 1517 res->desc = IORES_DESC_NONE; 1518 res->child = NULL; 1519 if (request_resource(parent, res) == 0) 1520 reserved = x+1; 1521 } 1522 } 1523 return 1; 1524 } 1525 __setup("reserve=", reserve_setup); 1526 1527 /* 1528 * Check if the requested addr and size spans more than any slot in the 1529 * iomem resource tree. 1530 */ 1531 int iomem_map_sanity_check(resource_size_t addr, unsigned long size) 1532 { 1533 struct resource *p = &iomem_resource; 1534 int err = 0; 1535 loff_t l; 1536 1537 read_lock(&resource_lock); 1538 for (p = p->child; p ; p = r_next(NULL, p, &l)) { 1539 /* 1540 * We can probably skip the resources without 1541 * IORESOURCE_IO attribute? 1542 */ 1543 if (p->start >= addr + size) 1544 continue; 1545 if (p->end < addr) 1546 continue; 1547 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && 1548 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) 1549 continue; 1550 /* 1551 * if a resource is "BUSY", it's not a hardware resource 1552 * but a driver mapping of such a resource; we don't want 1553 * to warn for those; some drivers legitimately map only 1554 * partial hardware resources. (example: vesafb) 1555 */ 1556 if (p->flags & IORESOURCE_BUSY) 1557 continue; 1558 1559 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n", 1560 (unsigned long long)addr, 1561 (unsigned long long)(addr + size - 1), 1562 p->name, p); 1563 err = -1; 1564 break; 1565 } 1566 read_unlock(&resource_lock); 1567 1568 return err; 1569 } 1570 1571 #ifdef CONFIG_STRICT_DEVMEM 1572 static int strict_iomem_checks = 1; 1573 #else 1574 static int strict_iomem_checks; 1575 #endif 1576 1577 /* 1578 * check if an address is reserved in the iomem resource tree 1579 * returns true if reserved, false if not reserved. 1580 */ 1581 bool iomem_is_exclusive(u64 addr) 1582 { 1583 struct resource *p = &iomem_resource; 1584 bool err = false; 1585 loff_t l; 1586 int size = PAGE_SIZE; 1587 1588 if (!strict_iomem_checks) 1589 return false; 1590 1591 addr = addr & PAGE_MASK; 1592 1593 read_lock(&resource_lock); 1594 for (p = p->child; p ; p = r_next(NULL, p, &l)) { 1595 /* 1596 * We can probably skip the resources without 1597 * IORESOURCE_IO attribute? 1598 */ 1599 if (p->start >= addr + size) 1600 break; 1601 if (p->end < addr) 1602 continue; 1603 /* 1604 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set 1605 * or CONFIG_IO_STRICT_DEVMEM is enabled and the 1606 * resource is busy. 1607 */ 1608 if ((p->flags & IORESOURCE_BUSY) == 0) 1609 continue; 1610 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) 1611 || p->flags & IORESOURCE_EXCLUSIVE) { 1612 err = true; 1613 break; 1614 } 1615 } 1616 read_unlock(&resource_lock); 1617 1618 return err; 1619 } 1620 1621 struct resource_entry *resource_list_create_entry(struct resource *res, 1622 size_t extra_size) 1623 { 1624 struct resource_entry *entry; 1625 1626 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL); 1627 if (entry) { 1628 INIT_LIST_HEAD(&entry->node); 1629 entry->res = res ? res : &entry->__res; 1630 } 1631 1632 return entry; 1633 } 1634 EXPORT_SYMBOL(resource_list_create_entry); 1635 1636 void resource_list_free(struct list_head *head) 1637 { 1638 struct resource_entry *entry, *tmp; 1639 1640 list_for_each_entry_safe(entry, tmp, head, node) 1641 resource_list_destroy_entry(entry); 1642 } 1643 EXPORT_SYMBOL(resource_list_free); 1644 1645 static int __init strict_iomem(char *str) 1646 { 1647 if (strstr(str, "relaxed")) 1648 strict_iomem_checks = 0; 1649 if (strstr(str, "strict")) 1650 strict_iomem_checks = 1; 1651 return 1; 1652 } 1653 1654 __setup("iomem=", strict_iomem); 1655