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