1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/kernel/resource.c 4 * 5 * Copyright (C) 1999 Linus Torvalds 6 * Copyright (C) 1999 Martin Mares <mj@ucw.cz> 7 * 8 * Arbitrary resource management. 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <linux/export.h> 14 #include <linux/errno.h> 15 #include <linux/ioport.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <linux/spinlock.h> 19 #include <linux/fs.h> 20 #include <linux/proc_fs.h> 21 #include <linux/pseudo_fs.h> 22 #include <linux/sched.h> 23 #include <linux/seq_file.h> 24 #include <linux/device.h> 25 #include <linux/pfn.h> 26 #include <linux/mm.h> 27 #include <linux/mount.h> 28 #include <linux/resource_ext.h> 29 #include <uapi/linux/magic.h> 30 #include <asm/io.h> 31 32 33 struct resource ioport_resource = { 34 .name = "PCI IO", 35 .start = 0, 36 .end = IO_SPACE_LIMIT, 37 .flags = IORESOURCE_IO, 38 }; 39 EXPORT_SYMBOL(ioport_resource); 40 41 struct resource iomem_resource = { 42 .name = "PCI mem", 43 .start = 0, 44 .end = -1, 45 .flags = IORESOURCE_MEM, 46 }; 47 EXPORT_SYMBOL(iomem_resource); 48 49 /* constraints to be met while allocating resources */ 50 struct resource_constraint { 51 resource_size_t min, max, align; 52 resource_size_t (*alignf)(void *, const struct resource *, 53 resource_size_t, resource_size_t); 54 void *alignf_data; 55 }; 56 57 static DEFINE_RWLOCK(resource_lock); 58 59 /* 60 * For memory hotplug, there is no way to free resource entries allocated 61 * by boot mem after the system is up. So for reusing the resource entry 62 * we need to remember the resource. 63 */ 64 static struct resource *bootmem_resource_free; 65 static DEFINE_SPINLOCK(bootmem_resource_lock); 66 67 static struct resource *next_resource(struct resource *p) 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 struct resource *next_resource_skip_children(struct resource *p) 77 { 78 while (!p->sibling && p->parent) 79 p = p->parent; 80 return p->sibling; 81 } 82 83 #define for_each_resource(_root, _p, _skip_children) \ 84 for ((_p) = (_root)->child; (_p); \ 85 (_p) = (_skip_children) ? next_resource_skip_children(_p) : \ 86 next_resource(_p)) 87 88 static void *r_next(struct seq_file *m, void *v, loff_t *pos) 89 { 90 struct resource *p = v; 91 (*pos)++; 92 return (void *)next_resource(p); 93 } 94 95 #ifdef CONFIG_PROC_FS 96 97 enum { MAX_IORES_LEVEL = 5 }; 98 99 static void *r_start(struct seq_file *m, loff_t *pos) 100 __acquires(resource_lock) 101 { 102 struct resource *p = PDE_DATA(file_inode(m->file)); 103 loff_t l = 0; 104 read_lock(&resource_lock); 105 for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) 106 ; 107 return p; 108 } 109 110 static void r_stop(struct seq_file *m, void *v) 111 __releases(resource_lock) 112 { 113 read_unlock(&resource_lock); 114 } 115 116 static int r_show(struct seq_file *m, void *v) 117 { 118 struct resource *root = PDE_DATA(file_inode(m->file)); 119 struct resource *r = v, *p; 120 unsigned long long start, end; 121 int width = root->end < 0x10000 ? 4 : 8; 122 int depth; 123 124 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) 125 if (p->parent == root) 126 break; 127 128 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) { 129 start = r->start; 130 end = r->end; 131 } else { 132 start = end = 0; 133 } 134 135 seq_printf(m, "%*s%0*llx-%0*llx : %s\n", 136 depth * 2, "", 137 width, start, 138 width, end, 139 r->name ? r->name : "<BAD>"); 140 return 0; 141 } 142 143 static const struct seq_operations resource_op = { 144 .start = r_start, 145 .next = r_next, 146 .stop = r_stop, 147 .show = r_show, 148 }; 149 150 static int __init ioresources_init(void) 151 { 152 proc_create_seq_data("ioports", 0, NULL, &resource_op, 153 &ioport_resource); 154 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource); 155 return 0; 156 } 157 __initcall(ioresources_init); 158 159 #endif /* CONFIG_PROC_FS */ 160 161 static void free_resource(struct resource *res) 162 { 163 if (!res) 164 return; 165 166 if (!PageSlab(virt_to_head_page(res))) { 167 spin_lock(&bootmem_resource_lock); 168 res->sibling = bootmem_resource_free; 169 bootmem_resource_free = res; 170 spin_unlock(&bootmem_resource_lock); 171 } else { 172 kfree(res); 173 } 174 } 175 176 static struct resource *alloc_resource(gfp_t flags) 177 { 178 struct resource *res = NULL; 179 180 spin_lock(&bootmem_resource_lock); 181 if (bootmem_resource_free) { 182 res = bootmem_resource_free; 183 bootmem_resource_free = res->sibling; 184 } 185 spin_unlock(&bootmem_resource_lock); 186 187 if (res) 188 memset(res, 0, sizeof(struct resource)); 189 else 190 res = kzalloc(sizeof(struct resource), flags); 191 192 return res; 193 } 194 195 /* Return the conflict entry if you can't request it */ 196 static struct resource * __request_resource(struct resource *root, struct resource *new) 197 { 198 resource_size_t start = new->start; 199 resource_size_t end = new->end; 200 struct resource *tmp, **p; 201 202 if (end < start) 203 return root; 204 if (start < root->start) 205 return root; 206 if (end > root->end) 207 return root; 208 p = &root->child; 209 for (;;) { 210 tmp = *p; 211 if (!tmp || tmp->start > end) { 212 new->sibling = tmp; 213 *p = new; 214 new->parent = root; 215 return NULL; 216 } 217 p = &tmp->sibling; 218 if (tmp->end < start) 219 continue; 220 return tmp; 221 } 222 } 223 224 static int __release_resource(struct resource *old, bool release_child) 225 { 226 struct resource *tmp, **p, *chd; 227 228 p = &old->parent->child; 229 for (;;) { 230 tmp = *p; 231 if (!tmp) 232 break; 233 if (tmp == old) { 234 if (release_child || !(tmp->child)) { 235 *p = tmp->sibling; 236 } else { 237 for (chd = tmp->child;; chd = chd->sibling) { 238 chd->parent = tmp->parent; 239 if (!(chd->sibling)) 240 break; 241 } 242 *p = tmp->child; 243 chd->sibling = tmp->sibling; 244 } 245 old->parent = NULL; 246 return 0; 247 } 248 p = &tmp->sibling; 249 } 250 return -EINVAL; 251 } 252 253 static void __release_child_resources(struct resource *r) 254 { 255 struct resource *tmp, *p; 256 resource_size_t size; 257 258 p = r->child; 259 r->child = NULL; 260 while (p) { 261 tmp = p; 262 p = p->sibling; 263 264 tmp->parent = NULL; 265 tmp->sibling = NULL; 266 __release_child_resources(tmp); 267 268 printk(KERN_DEBUG "release child resource %pR\n", tmp); 269 /* need to restore size, and keep flags */ 270 size = resource_size(tmp); 271 tmp->start = 0; 272 tmp->end = size - 1; 273 } 274 } 275 276 void release_child_resources(struct resource *r) 277 { 278 write_lock(&resource_lock); 279 __release_child_resources(r); 280 write_unlock(&resource_lock); 281 } 282 283 /** 284 * request_resource_conflict - request and reserve an I/O or memory resource 285 * @root: root resource descriptor 286 * @new: resource descriptor desired by caller 287 * 288 * Returns 0 for success, conflict resource on error. 289 */ 290 struct resource *request_resource_conflict(struct resource *root, struct resource *new) 291 { 292 struct resource *conflict; 293 294 write_lock(&resource_lock); 295 conflict = __request_resource(root, new); 296 write_unlock(&resource_lock); 297 return conflict; 298 } 299 300 /** 301 * request_resource - request and reserve an I/O or memory resource 302 * @root: root resource descriptor 303 * @new: resource descriptor desired by caller 304 * 305 * Returns 0 for success, negative error code on error. 306 */ 307 int request_resource(struct resource *root, struct resource *new) 308 { 309 struct resource *conflict; 310 311 conflict = request_resource_conflict(root, new); 312 return conflict ? -EBUSY : 0; 313 } 314 315 EXPORT_SYMBOL(request_resource); 316 317 /** 318 * release_resource - release a previously reserved resource 319 * @old: resource pointer 320 */ 321 int release_resource(struct resource *old) 322 { 323 int retval; 324 325 write_lock(&resource_lock); 326 retval = __release_resource(old, true); 327 write_unlock(&resource_lock); 328 return retval; 329 } 330 331 EXPORT_SYMBOL(release_resource); 332 333 /** 334 * find_next_iomem_res - Finds the lowest iomem resource that covers part of 335 * [@start..@end]. 336 * 337 * If a resource is found, returns 0 and @*res is overwritten with the part 338 * of the resource that's within [@start..@end]; if none is found, returns 339 * -ENODEV. Returns -EINVAL for invalid parameters. 340 * 341 * @start: start address of the resource searched for 342 * @end: end address of same resource 343 * @flags: flags which the resource must have 344 * @desc: descriptor the resource must have 345 * @res: return ptr, if resource found 346 * 347 * The caller must specify @start, @end, @flags, and @desc 348 * (which may be IORES_DESC_NONE). 349 */ 350 static int find_next_iomem_res(resource_size_t start, resource_size_t end, 351 unsigned long flags, unsigned long desc, 352 struct resource *res) 353 { 354 struct resource *p; 355 356 if (!res) 357 return -EINVAL; 358 359 if (start >= end) 360 return -EINVAL; 361 362 read_lock(&resource_lock); 363 364 for (p = iomem_resource.child; p; p = next_resource(p)) { 365 /* If we passed the resource we are looking for, stop */ 366 if (p->start > end) { 367 p = NULL; 368 break; 369 } 370 371 /* Skip until we find a range that matches what we look for */ 372 if (p->end < start) 373 continue; 374 375 if ((p->flags & flags) != flags) 376 continue; 377 if ((desc != IORES_DESC_NONE) && (desc != p->desc)) 378 continue; 379 380 /* Found a match, break */ 381 break; 382 } 383 384 if (p) { 385 /* copy data */ 386 *res = (struct resource) { 387 .start = max(start, p->start), 388 .end = min(end, p->end), 389 .flags = p->flags, 390 .desc = p->desc, 391 .parent = p->parent, 392 }; 393 } 394 395 read_unlock(&resource_lock); 396 return p ? 0 : -ENODEV; 397 } 398 399 static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, 400 unsigned long flags, unsigned long desc, 401 void *arg, 402 int (*func)(struct resource *, void *)) 403 { 404 struct resource res; 405 int ret = -EINVAL; 406 407 while (start < end && 408 !find_next_iomem_res(start, end, flags, desc, &res)) { 409 ret = (*func)(&res, arg); 410 if (ret) 411 break; 412 413 start = res.end + 1; 414 } 415 416 return ret; 417 } 418 419 /** 420 * walk_iomem_res_desc - Walks through iomem resources and calls func() 421 * with matching resource ranges. 422 * * 423 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check. 424 * @flags: I/O resource flags 425 * @start: start addr 426 * @end: end addr 427 * @arg: function argument for the callback @func 428 * @func: callback function that is called for each qualifying resource area 429 * 430 * All the memory ranges which overlap start,end and also match flags and 431 * desc are valid candidates. 432 * 433 * NOTE: For a new descriptor search, define a new IORES_DESC in 434 * <linux/ioport.h> and set it in 'desc' of a target resource entry. 435 */ 436 int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, 437 u64 end, void *arg, int (*func)(struct resource *, void *)) 438 { 439 return __walk_iomem_res_desc(start, end, flags, desc, arg, func); 440 } 441 EXPORT_SYMBOL_GPL(walk_iomem_res_desc); 442 443 /* 444 * This function calls the @func callback against all memory ranges of type 445 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. 446 * Now, this function is only for System RAM, it deals with full ranges and 447 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate 448 * ranges. 449 */ 450 int walk_system_ram_res(u64 start, u64 end, void *arg, 451 int (*func)(struct resource *, void *)) 452 { 453 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 454 455 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg, 456 func); 457 } 458 459 /* 460 * This function calls the @func callback against all memory ranges, which 461 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. 462 */ 463 int walk_mem_res(u64 start, u64 end, void *arg, 464 int (*func)(struct resource *, void *)) 465 { 466 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; 467 468 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg, 469 func); 470 } 471 472 /* 473 * This function calls the @func callback against all memory ranges of type 474 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. 475 * It is to be used only for System RAM. 476 */ 477 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, 478 void *arg, int (*func)(unsigned long, unsigned long, void *)) 479 { 480 resource_size_t start, end; 481 unsigned long flags; 482 struct resource res; 483 unsigned long pfn, end_pfn; 484 int ret = -EINVAL; 485 486 start = (u64) start_pfn << PAGE_SHIFT; 487 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; 488 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 489 while (start < end && 490 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) { 491 pfn = PFN_UP(res.start); 492 end_pfn = PFN_DOWN(res.end + 1); 493 if (end_pfn > pfn) 494 ret = (*func)(pfn, end_pfn - pfn, arg); 495 if (ret) 496 break; 497 start = res.end + 1; 498 } 499 return ret; 500 } 501 502 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) 503 { 504 return 1; 505 } 506 507 /* 508 * This generic page_is_ram() returns true if specified address is 509 * registered as System RAM in iomem_resource list. 510 */ 511 int __weak page_is_ram(unsigned long pfn) 512 { 513 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; 514 } 515 EXPORT_SYMBOL_GPL(page_is_ram); 516 517 static int __region_intersects(resource_size_t start, size_t size, 518 unsigned long flags, unsigned long desc) 519 { 520 struct resource res; 521 int type = 0; int other = 0; 522 struct resource *p; 523 524 res.start = start; 525 res.end = start + size - 1; 526 527 for (p = iomem_resource.child; p ; p = p->sibling) { 528 bool is_type = (((p->flags & flags) == flags) && 529 ((desc == IORES_DESC_NONE) || 530 (desc == p->desc))); 531 532 if (resource_overlaps(p, &res)) 533 is_type ? type++ : other++; 534 } 535 536 if (type == 0) 537 return REGION_DISJOINT; 538 539 if (other == 0) 540 return REGION_INTERSECTS; 541 542 return REGION_MIXED; 543 } 544 545 /** 546 * region_intersects() - determine intersection of region with known resources 547 * @start: region start address 548 * @size: size of region 549 * @flags: flags of resource (in iomem_resource) 550 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE 551 * 552 * Check if the specified region partially overlaps or fully eclipses a 553 * resource identified by @flags and @desc (optional with IORES_DESC_NONE). 554 * Return REGION_DISJOINT if the region does not overlap @flags/@desc, 555 * return REGION_MIXED if the region overlaps @flags/@desc and another 556 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc 557 * and no other defined resource. Note that REGION_INTERSECTS is also 558 * returned in the case when the specified region overlaps RAM and undefined 559 * memory holes. 560 * 561 * region_intersect() is used by memory remapping functions to ensure 562 * the user is not remapping RAM and is a vast speed up over walking 563 * through the resource table page by page. 564 */ 565 int region_intersects(resource_size_t start, size_t size, unsigned long flags, 566 unsigned long desc) 567 { 568 int ret; 569 570 read_lock(&resource_lock); 571 ret = __region_intersects(start, size, flags, desc); 572 read_unlock(&resource_lock); 573 574 return ret; 575 } 576 EXPORT_SYMBOL_GPL(region_intersects); 577 578 void __weak arch_remove_reservations(struct resource *avail) 579 { 580 } 581 582 static resource_size_t simple_align_resource(void *data, 583 const struct resource *avail, 584 resource_size_t size, 585 resource_size_t align) 586 { 587 return avail->start; 588 } 589 590 static void resource_clip(struct resource *res, resource_size_t min, 591 resource_size_t max) 592 { 593 if (res->start < min) 594 res->start = min; 595 if (res->end > max) 596 res->end = max; 597 } 598 599 /* 600 * Find empty slot in the resource tree with the given range and 601 * alignment constraints 602 */ 603 static int __find_resource(struct resource *root, struct resource *old, 604 struct resource *new, 605 resource_size_t size, 606 struct resource_constraint *constraint) 607 { 608 struct resource *this = root->child; 609 struct resource tmp = *new, avail, alloc; 610 611 tmp.start = root->start; 612 /* 613 * Skip past an allocated resource that starts at 0, since the assignment 614 * of this->start - 1 to tmp->end below would cause an underflow. 615 */ 616 if (this && this->start == root->start) { 617 tmp.start = (this == old) ? old->start : this->end + 1; 618 this = this->sibling; 619 } 620 for(;;) { 621 if (this) 622 tmp.end = (this == old) ? this->end : this->start - 1; 623 else 624 tmp.end = root->end; 625 626 if (tmp.end < tmp.start) 627 goto next; 628 629 resource_clip(&tmp, constraint->min, constraint->max); 630 arch_remove_reservations(&tmp); 631 632 /* Check for overflow after ALIGN() */ 633 avail.start = ALIGN(tmp.start, constraint->align); 634 avail.end = tmp.end; 635 avail.flags = new->flags & ~IORESOURCE_UNSET; 636 if (avail.start >= tmp.start) { 637 alloc.flags = avail.flags; 638 alloc.start = constraint->alignf(constraint->alignf_data, &avail, 639 size, constraint->align); 640 alloc.end = alloc.start + size - 1; 641 if (alloc.start <= alloc.end && 642 resource_contains(&avail, &alloc)) { 643 new->start = alloc.start; 644 new->end = alloc.end; 645 return 0; 646 } 647 } 648 649 next: if (!this || this->end == root->end) 650 break; 651 652 if (this != old) 653 tmp.start = this->end + 1; 654 this = this->sibling; 655 } 656 return -EBUSY; 657 } 658 659 /* 660 * Find empty slot in the resource tree given range and alignment. 661 */ 662 static int find_resource(struct resource *root, struct resource *new, 663 resource_size_t size, 664 struct resource_constraint *constraint) 665 { 666 return __find_resource(root, NULL, new, size, constraint); 667 } 668 669 /** 670 * reallocate_resource - allocate a slot in the resource tree given range & alignment. 671 * The resource will be relocated if the new size cannot be reallocated in the 672 * current location. 673 * 674 * @root: root resource descriptor 675 * @old: resource descriptor desired by caller 676 * @newsize: new size of the resource descriptor 677 * @constraint: the size and alignment constraints to be met. 678 */ 679 static int reallocate_resource(struct resource *root, struct resource *old, 680 resource_size_t newsize, 681 struct resource_constraint *constraint) 682 { 683 int err=0; 684 struct resource new = *old; 685 struct resource *conflict; 686 687 write_lock(&resource_lock); 688 689 if ((err = __find_resource(root, old, &new, newsize, constraint))) 690 goto out; 691 692 if (resource_contains(&new, old)) { 693 old->start = new.start; 694 old->end = new.end; 695 goto out; 696 } 697 698 if (old->child) { 699 err = -EBUSY; 700 goto out; 701 } 702 703 if (resource_contains(old, &new)) { 704 old->start = new.start; 705 old->end = new.end; 706 } else { 707 __release_resource(old, true); 708 *old = new; 709 conflict = __request_resource(root, old); 710 BUG_ON(conflict); 711 } 712 out: 713 write_unlock(&resource_lock); 714 return err; 715 } 716 717 718 /** 719 * allocate_resource - allocate empty slot in the resource tree given range & alignment. 720 * The resource will be reallocated with a new size if it was already allocated 721 * @root: root resource descriptor 722 * @new: resource descriptor desired by caller 723 * @size: requested resource region size 724 * @min: minimum boundary to allocate 725 * @max: maximum boundary to allocate 726 * @align: alignment requested, in bytes 727 * @alignf: alignment function, optional, called if not NULL 728 * @alignf_data: arbitrary data to pass to the @alignf function 729 */ 730 int allocate_resource(struct resource *root, struct resource *new, 731 resource_size_t size, resource_size_t min, 732 resource_size_t max, resource_size_t align, 733 resource_size_t (*alignf)(void *, 734 const struct resource *, 735 resource_size_t, 736 resource_size_t), 737 void *alignf_data) 738 { 739 int err; 740 struct resource_constraint constraint; 741 742 if (!alignf) 743 alignf = simple_align_resource; 744 745 constraint.min = min; 746 constraint.max = max; 747 constraint.align = align; 748 constraint.alignf = alignf; 749 constraint.alignf_data = alignf_data; 750 751 if ( new->parent ) { 752 /* resource is already allocated, try reallocating with 753 the new constraints */ 754 return reallocate_resource(root, new, size, &constraint); 755 } 756 757 write_lock(&resource_lock); 758 err = find_resource(root, new, size, &constraint); 759 if (err >= 0 && __request_resource(root, new)) 760 err = -EBUSY; 761 write_unlock(&resource_lock); 762 return err; 763 } 764 765 EXPORT_SYMBOL(allocate_resource); 766 767 /** 768 * lookup_resource - find an existing resource by a resource start address 769 * @root: root resource descriptor 770 * @start: resource start address 771 * 772 * Returns a pointer to the resource if found, NULL otherwise 773 */ 774 struct resource *lookup_resource(struct resource *root, resource_size_t start) 775 { 776 struct resource *res; 777 778 read_lock(&resource_lock); 779 for (res = root->child; res; res = res->sibling) { 780 if (res->start == start) 781 break; 782 } 783 read_unlock(&resource_lock); 784 785 return res; 786 } 787 788 /* 789 * Insert a resource into the resource tree. If successful, return NULL, 790 * otherwise return the conflicting resource (compare to __request_resource()) 791 */ 792 static struct resource * __insert_resource(struct resource *parent, struct resource *new) 793 { 794 struct resource *first, *next; 795 796 for (;; parent = first) { 797 first = __request_resource(parent, new); 798 if (!first) 799 return first; 800 801 if (first == parent) 802 return first; 803 if (WARN_ON(first == new)) /* duplicated insertion */ 804 return first; 805 806 if ((first->start > new->start) || (first->end < new->end)) 807 break; 808 if ((first->start == new->start) && (first->end == new->end)) 809 break; 810 } 811 812 for (next = first; ; next = next->sibling) { 813 /* Partial overlap? Bad, and unfixable */ 814 if (next->start < new->start || next->end > new->end) 815 return next; 816 if (!next->sibling) 817 break; 818 if (next->sibling->start > new->end) 819 break; 820 } 821 822 new->parent = parent; 823 new->sibling = next->sibling; 824 new->child = first; 825 826 next->sibling = NULL; 827 for (next = first; next; next = next->sibling) 828 next->parent = new; 829 830 if (parent->child == first) { 831 parent->child = new; 832 } else { 833 next = parent->child; 834 while (next->sibling != first) 835 next = next->sibling; 836 next->sibling = new; 837 } 838 return NULL; 839 } 840 841 /** 842 * insert_resource_conflict - Inserts resource in the resource tree 843 * @parent: parent of the new resource 844 * @new: new resource to insert 845 * 846 * Returns 0 on success, conflict resource if the resource can't be inserted. 847 * 848 * This function is equivalent to request_resource_conflict when no conflict 849 * happens. If a conflict happens, and the conflicting resources 850 * entirely fit within the range of the new resource, then the new 851 * resource is inserted and the conflicting resources become children of 852 * the new resource. 853 * 854 * This function is intended for producers of resources, such as FW modules 855 * and bus drivers. 856 */ 857 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) 858 { 859 struct resource *conflict; 860 861 write_lock(&resource_lock); 862 conflict = __insert_resource(parent, new); 863 write_unlock(&resource_lock); 864 return conflict; 865 } 866 867 /** 868 * insert_resource - Inserts a resource in the resource tree 869 * @parent: parent of the new resource 870 * @new: new resource to insert 871 * 872 * Returns 0 on success, -EBUSY if the resource can't be inserted. 873 * 874 * This function is intended for producers of resources, such as FW modules 875 * and bus drivers. 876 */ 877 int insert_resource(struct resource *parent, struct resource *new) 878 { 879 struct resource *conflict; 880 881 conflict = insert_resource_conflict(parent, new); 882 return conflict ? -EBUSY : 0; 883 } 884 EXPORT_SYMBOL_GPL(insert_resource); 885 886 /** 887 * insert_resource_expand_to_fit - Insert a resource into the resource tree 888 * @root: root resource descriptor 889 * @new: new resource to insert 890 * 891 * Insert a resource into the resource tree, possibly expanding it in order 892 * to make it encompass any conflicting resources. 893 */ 894 void insert_resource_expand_to_fit(struct resource *root, struct resource *new) 895 { 896 if (new->parent) 897 return; 898 899 write_lock(&resource_lock); 900 for (;;) { 901 struct resource *conflict; 902 903 conflict = __insert_resource(root, new); 904 if (!conflict) 905 break; 906 if (conflict == root) 907 break; 908 909 /* Ok, expand resource to cover the conflict, then try again .. */ 910 if (conflict->start < new->start) 911 new->start = conflict->start; 912 if (conflict->end > new->end) 913 new->end = conflict->end; 914 915 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); 916 } 917 write_unlock(&resource_lock); 918 } 919 920 /** 921 * remove_resource - Remove a resource in the resource tree 922 * @old: resource to remove 923 * 924 * Returns 0 on success, -EINVAL if the resource is not valid. 925 * 926 * This function removes a resource previously inserted by insert_resource() 927 * or insert_resource_conflict(), and moves the children (if any) up to 928 * where they were before. insert_resource() and insert_resource_conflict() 929 * insert a new resource, and move any conflicting resources down to the 930 * children of the new resource. 931 * 932 * insert_resource(), insert_resource_conflict() and remove_resource() are 933 * intended for producers of resources, such as FW modules and bus drivers. 934 */ 935 int remove_resource(struct resource *old) 936 { 937 int retval; 938 939 write_lock(&resource_lock); 940 retval = __release_resource(old, false); 941 write_unlock(&resource_lock); 942 return retval; 943 } 944 EXPORT_SYMBOL_GPL(remove_resource); 945 946 static int __adjust_resource(struct resource *res, resource_size_t start, 947 resource_size_t size) 948 { 949 struct resource *tmp, *parent = res->parent; 950 resource_size_t end = start + size - 1; 951 int result = -EBUSY; 952 953 if (!parent) 954 goto skip; 955 956 if ((start < parent->start) || (end > parent->end)) 957 goto out; 958 959 if (res->sibling && (res->sibling->start <= end)) 960 goto out; 961 962 tmp = parent->child; 963 if (tmp != res) { 964 while (tmp->sibling != res) 965 tmp = tmp->sibling; 966 if (start <= tmp->end) 967 goto out; 968 } 969 970 skip: 971 for (tmp = res->child; tmp; tmp = tmp->sibling) 972 if ((tmp->start < start) || (tmp->end > end)) 973 goto out; 974 975 res->start = start; 976 res->end = end; 977 result = 0; 978 979 out: 980 return result; 981 } 982 983 /** 984 * adjust_resource - modify a resource's start and size 985 * @res: resource to modify 986 * @start: new start value 987 * @size: new size 988 * 989 * Given an existing resource, change its start and size to match the 990 * arguments. Returns 0 on success, -EBUSY if it can't fit. 991 * Existing children of the resource are assumed to be immutable. 992 */ 993 int adjust_resource(struct resource *res, resource_size_t start, 994 resource_size_t size) 995 { 996 int result; 997 998 write_lock(&resource_lock); 999 result = __adjust_resource(res, start, size); 1000 write_unlock(&resource_lock); 1001 return result; 1002 } 1003 EXPORT_SYMBOL(adjust_resource); 1004 1005 static void __init 1006 __reserve_region_with_split(struct resource *root, resource_size_t start, 1007 resource_size_t end, const char *name) 1008 { 1009 struct resource *parent = root; 1010 struct resource *conflict; 1011 struct resource *res = alloc_resource(GFP_ATOMIC); 1012 struct resource *next_res = NULL; 1013 int type = resource_type(root); 1014 1015 if (!res) 1016 return; 1017 1018 res->name = name; 1019 res->start = start; 1020 res->end = end; 1021 res->flags = type | IORESOURCE_BUSY; 1022 res->desc = IORES_DESC_NONE; 1023 1024 while (1) { 1025 1026 conflict = __request_resource(parent, res); 1027 if (!conflict) { 1028 if (!next_res) 1029 break; 1030 res = next_res; 1031 next_res = NULL; 1032 continue; 1033 } 1034 1035 /* conflict covered whole area */ 1036 if (conflict->start <= res->start && 1037 conflict->end >= res->end) { 1038 free_resource(res); 1039 WARN_ON(next_res); 1040 break; 1041 } 1042 1043 /* failed, split and try again */ 1044 if (conflict->start > res->start) { 1045 end = res->end; 1046 res->end = conflict->start - 1; 1047 if (conflict->end < end) { 1048 next_res = alloc_resource(GFP_ATOMIC); 1049 if (!next_res) { 1050 free_resource(res); 1051 break; 1052 } 1053 next_res->name = name; 1054 next_res->start = conflict->end + 1; 1055 next_res->end = end; 1056 next_res->flags = type | IORESOURCE_BUSY; 1057 next_res->desc = IORES_DESC_NONE; 1058 } 1059 } else { 1060 res->start = conflict->end + 1; 1061 } 1062 } 1063 1064 } 1065 1066 void __init 1067 reserve_region_with_split(struct resource *root, resource_size_t start, 1068 resource_size_t end, const char *name) 1069 { 1070 int abort = 0; 1071 1072 write_lock(&resource_lock); 1073 if (root->start > start || root->end < end) { 1074 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", 1075 (unsigned long long)start, (unsigned long long)end, 1076 root); 1077 if (start > root->end || end < root->start) 1078 abort = 1; 1079 else { 1080 if (end > root->end) 1081 end = root->end; 1082 if (start < root->start) 1083 start = root->start; 1084 pr_err("fixing request to [0x%llx-0x%llx]\n", 1085 (unsigned long long)start, 1086 (unsigned long long)end); 1087 } 1088 dump_stack(); 1089 } 1090 if (!abort) 1091 __reserve_region_with_split(root, start, end, name); 1092 write_unlock(&resource_lock); 1093 } 1094 1095 /** 1096 * resource_alignment - calculate resource's alignment 1097 * @res: resource pointer 1098 * 1099 * Returns alignment on success, 0 (invalid alignment) on failure. 1100 */ 1101 resource_size_t resource_alignment(struct resource *res) 1102 { 1103 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { 1104 case IORESOURCE_SIZEALIGN: 1105 return resource_size(res); 1106 case IORESOURCE_STARTALIGN: 1107 return res->start; 1108 default: 1109 return 0; 1110 } 1111 } 1112 1113 /* 1114 * This is compatibility stuff for IO resources. 1115 * 1116 * Note how this, unlike the above, knows about 1117 * the IO flag meanings (busy etc). 1118 * 1119 * request_region creates a new busy region. 1120 * 1121 * release_region releases a matching busy region. 1122 */ 1123 1124 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); 1125 1126 static struct inode *iomem_inode; 1127 1128 #ifdef CONFIG_IO_STRICT_DEVMEM 1129 static void revoke_iomem(struct resource *res) 1130 { 1131 /* pairs with smp_store_release() in iomem_init_inode() */ 1132 struct inode *inode = smp_load_acquire(&iomem_inode); 1133 1134 /* 1135 * Check that the initialization has completed. Losing the race 1136 * is ok because it means drivers are claiming resources before 1137 * the fs_initcall level of init and prevent iomem_get_mapping users 1138 * from establishing mappings. 1139 */ 1140 if (!inode) 1141 return; 1142 1143 /* 1144 * The expectation is that the driver has successfully marked 1145 * the resource busy by this point, so devmem_is_allowed() 1146 * should start returning false, however for performance this 1147 * does not iterate the entire resource range. 1148 */ 1149 if (devmem_is_allowed(PHYS_PFN(res->start)) && 1150 devmem_is_allowed(PHYS_PFN(res->end))) { 1151 /* 1152 * *cringe* iomem=relaxed says "go ahead, what's the 1153 * worst that can happen?" 1154 */ 1155 return; 1156 } 1157 1158 unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1); 1159 } 1160 #else 1161 static void revoke_iomem(struct resource *res) {} 1162 #endif 1163 1164 struct address_space *iomem_get_mapping(void) 1165 { 1166 /* 1167 * This function is only called from file open paths, hence guaranteed 1168 * that fs_initcalls have completed and no need to check for NULL. But 1169 * since revoke_iomem can be called before the initcall we still need 1170 * the barrier to appease checkers. 1171 */ 1172 return smp_load_acquire(&iomem_inode)->i_mapping; 1173 } 1174 1175 static int __request_region_locked(struct resource *res, struct resource *parent, 1176 resource_size_t start, resource_size_t n, 1177 const char *name, int flags) 1178 { 1179 DECLARE_WAITQUEUE(wait, current); 1180 1181 res->name = name; 1182 res->start = start; 1183 res->end = start + n - 1; 1184 1185 for (;;) { 1186 struct resource *conflict; 1187 1188 res->flags = resource_type(parent) | resource_ext_type(parent); 1189 res->flags |= IORESOURCE_BUSY | flags; 1190 res->desc = parent->desc; 1191 1192 conflict = __request_resource(parent, res); 1193 if (!conflict) 1194 break; 1195 /* 1196 * mm/hmm.c reserves physical addresses which then 1197 * become unavailable to other users. Conflicts are 1198 * not expected. Warn to aid debugging if encountered. 1199 */ 1200 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { 1201 pr_warn("Unaddressable device %s %pR conflicts with %pR", 1202 conflict->name, conflict, res); 1203 } 1204 if (conflict != parent) { 1205 if (!(conflict->flags & IORESOURCE_BUSY)) { 1206 parent = conflict; 1207 continue; 1208 } 1209 } 1210 if (conflict->flags & flags & IORESOURCE_MUXED) { 1211 add_wait_queue(&muxed_resource_wait, &wait); 1212 write_unlock(&resource_lock); 1213 set_current_state(TASK_UNINTERRUPTIBLE); 1214 schedule(); 1215 remove_wait_queue(&muxed_resource_wait, &wait); 1216 write_lock(&resource_lock); 1217 continue; 1218 } 1219 /* Uhhuh, that didn't work out.. */ 1220 return -EBUSY; 1221 } 1222 1223 return 0; 1224 } 1225 1226 /** 1227 * __request_region - create a new busy resource region 1228 * @parent: parent resource descriptor 1229 * @start: resource start address 1230 * @n: resource region size 1231 * @name: reserving caller's ID string 1232 * @flags: IO resource flags 1233 */ 1234 struct resource *__request_region(struct resource *parent, 1235 resource_size_t start, resource_size_t n, 1236 const char *name, int flags) 1237 { 1238 struct resource *res = alloc_resource(GFP_KERNEL); 1239 int ret; 1240 1241 if (!res) 1242 return NULL; 1243 1244 write_lock(&resource_lock); 1245 ret = __request_region_locked(res, parent, start, n, name, flags); 1246 write_unlock(&resource_lock); 1247 1248 if (ret) { 1249 free_resource(res); 1250 return NULL; 1251 } 1252 1253 if (parent == &iomem_resource) 1254 revoke_iomem(res); 1255 1256 return res; 1257 } 1258 EXPORT_SYMBOL(__request_region); 1259 1260 /** 1261 * __release_region - release a previously reserved resource region 1262 * @parent: parent resource descriptor 1263 * @start: resource start address 1264 * @n: resource region size 1265 * 1266 * The described resource region must match a currently busy region. 1267 */ 1268 void __release_region(struct resource *parent, resource_size_t start, 1269 resource_size_t n) 1270 { 1271 struct resource **p; 1272 resource_size_t end; 1273 1274 p = &parent->child; 1275 end = start + n - 1; 1276 1277 write_lock(&resource_lock); 1278 1279 for (;;) { 1280 struct resource *res = *p; 1281 1282 if (!res) 1283 break; 1284 if (res->start <= start && res->end >= end) { 1285 if (!(res->flags & IORESOURCE_BUSY)) { 1286 p = &res->child; 1287 continue; 1288 } 1289 if (res->start != start || res->end != end) 1290 break; 1291 *p = res->sibling; 1292 write_unlock(&resource_lock); 1293 if (res->flags & IORESOURCE_MUXED) 1294 wake_up(&muxed_resource_wait); 1295 free_resource(res); 1296 return; 1297 } 1298 p = &res->sibling; 1299 } 1300 1301 write_unlock(&resource_lock); 1302 1303 printk(KERN_WARNING "Trying to free nonexistent resource " 1304 "<%016llx-%016llx>\n", (unsigned long long)start, 1305 (unsigned long long)end); 1306 } 1307 EXPORT_SYMBOL(__release_region); 1308 1309 #ifdef CONFIG_MEMORY_HOTREMOVE 1310 /** 1311 * release_mem_region_adjustable - release a previously reserved memory region 1312 * @start: resource start address 1313 * @size: resource region size 1314 * 1315 * This interface is intended for memory hot-delete. The requested region 1316 * is released from a currently busy memory resource. The requested region 1317 * must either match exactly or fit into a single busy resource entry. In 1318 * the latter case, the remaining resource is adjusted accordingly. 1319 * Existing children of the busy memory resource must be immutable in the 1320 * request. 1321 * 1322 * Note: 1323 * - Additional release conditions, such as overlapping region, can be 1324 * supported after they are confirmed as valid cases. 1325 * - When a busy memory resource gets split into two entries, the code 1326 * assumes that all children remain in the lower address entry for 1327 * simplicity. Enhance this logic when necessary. 1328 */ 1329 void release_mem_region_adjustable(resource_size_t start, resource_size_t size) 1330 { 1331 struct resource *parent = &iomem_resource; 1332 struct resource *new_res = NULL; 1333 bool alloc_nofail = false; 1334 struct resource **p; 1335 struct resource *res; 1336 resource_size_t end; 1337 1338 end = start + size - 1; 1339 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end))) 1340 return; 1341 1342 /* 1343 * We free up quite a lot of memory on memory hotunplug (esp., memap), 1344 * just before releasing the region. This is highly unlikely to 1345 * fail - let's play save and make it never fail as the caller cannot 1346 * perform any error handling (e.g., trying to re-add memory will fail 1347 * similarly). 1348 */ 1349 retry: 1350 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0)); 1351 1352 p = &parent->child; 1353 write_lock(&resource_lock); 1354 1355 while ((res = *p)) { 1356 if (res->start >= end) 1357 break; 1358 1359 /* look for the next resource if it does not fit into */ 1360 if (res->start > start || res->end < end) { 1361 p = &res->sibling; 1362 continue; 1363 } 1364 1365 /* 1366 * All memory regions added from memory-hotplug path have the 1367 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have 1368 * this flag, we know that we are dealing with a resource coming 1369 * from HMM/devm. HMM/devm use another mechanism to add/release 1370 * a resource. This goes via devm_request_mem_region and 1371 * devm_release_mem_region. 1372 * HMM/devm take care to release their resources when they want, 1373 * so if we are dealing with them, let us just back off here. 1374 */ 1375 if (!(res->flags & IORESOURCE_SYSRAM)) { 1376 break; 1377 } 1378 1379 if (!(res->flags & IORESOURCE_MEM)) 1380 break; 1381 1382 if (!(res->flags & IORESOURCE_BUSY)) { 1383 p = &res->child; 1384 continue; 1385 } 1386 1387 /* found the target resource; let's adjust accordingly */ 1388 if (res->start == start && res->end == end) { 1389 /* free the whole entry */ 1390 *p = res->sibling; 1391 free_resource(res); 1392 } else if (res->start == start && res->end != end) { 1393 /* adjust the start */ 1394 WARN_ON_ONCE(__adjust_resource(res, end + 1, 1395 res->end - end)); 1396 } else if (res->start != start && res->end == end) { 1397 /* adjust the end */ 1398 WARN_ON_ONCE(__adjust_resource(res, res->start, 1399 start - res->start)); 1400 } else { 1401 /* split into two entries - we need a new resource */ 1402 if (!new_res) { 1403 new_res = alloc_resource(GFP_ATOMIC); 1404 if (!new_res) { 1405 alloc_nofail = true; 1406 write_unlock(&resource_lock); 1407 goto retry; 1408 } 1409 } 1410 new_res->name = res->name; 1411 new_res->start = end + 1; 1412 new_res->end = res->end; 1413 new_res->flags = res->flags; 1414 new_res->desc = res->desc; 1415 new_res->parent = res->parent; 1416 new_res->sibling = res->sibling; 1417 new_res->child = NULL; 1418 1419 if (WARN_ON_ONCE(__adjust_resource(res, res->start, 1420 start - res->start))) 1421 break; 1422 res->sibling = new_res; 1423 new_res = NULL; 1424 } 1425 1426 break; 1427 } 1428 1429 write_unlock(&resource_lock); 1430 free_resource(new_res); 1431 } 1432 #endif /* CONFIG_MEMORY_HOTREMOVE */ 1433 1434 #ifdef CONFIG_MEMORY_HOTPLUG 1435 static bool system_ram_resources_mergeable(struct resource *r1, 1436 struct resource *r2) 1437 { 1438 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */ 1439 return r1->flags == r2->flags && r1->end + 1 == r2->start && 1440 r1->name == r2->name && r1->desc == r2->desc && 1441 !r1->child && !r2->child; 1442 } 1443 1444 /** 1445 * merge_system_ram_resource - mark the System RAM resource mergeable and try to 1446 * merge it with adjacent, mergeable resources 1447 * @res: resource descriptor 1448 * 1449 * This interface is intended for memory hotplug, whereby lots of contiguous 1450 * system ram resources are added (e.g., via add_memory*()) by a driver, and 1451 * the actual resource boundaries are not of interest (e.g., it might be 1452 * relevant for DIMMs). Only resources that are marked mergeable, that have the 1453 * same parent, and that don't have any children are considered. All mergeable 1454 * resources must be immutable during the request. 1455 * 1456 * Note: 1457 * - The caller has to make sure that no pointers to resources that are 1458 * marked mergeable are used anymore after this call - the resource might 1459 * be freed and the pointer might be stale! 1460 * - release_mem_region_adjustable() will split on demand on memory hotunplug 1461 */ 1462 void merge_system_ram_resource(struct resource *res) 1463 { 1464 const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 1465 struct resource *cur; 1466 1467 if (WARN_ON_ONCE((res->flags & flags) != flags)) 1468 return; 1469 1470 write_lock(&resource_lock); 1471 res->flags |= IORESOURCE_SYSRAM_MERGEABLE; 1472 1473 /* Try to merge with next item in the list. */ 1474 cur = res->sibling; 1475 if (cur && system_ram_resources_mergeable(res, cur)) { 1476 res->end = cur->end; 1477 res->sibling = cur->sibling; 1478 free_resource(cur); 1479 } 1480 1481 /* Try to merge with previous item in the list. */ 1482 cur = res->parent->child; 1483 while (cur && cur->sibling != res) 1484 cur = cur->sibling; 1485 if (cur && system_ram_resources_mergeable(cur, res)) { 1486 cur->end = res->end; 1487 cur->sibling = res->sibling; 1488 free_resource(res); 1489 } 1490 write_unlock(&resource_lock); 1491 } 1492 #endif /* CONFIG_MEMORY_HOTPLUG */ 1493 1494 /* 1495 * Managed region resource 1496 */ 1497 static void devm_resource_release(struct device *dev, void *ptr) 1498 { 1499 struct resource **r = ptr; 1500 1501 release_resource(*r); 1502 } 1503 1504 /** 1505 * devm_request_resource() - request and reserve an I/O or memory resource 1506 * @dev: device for which to request the resource 1507 * @root: root of the resource tree from which to request the resource 1508 * @new: descriptor of the resource to request 1509 * 1510 * This is a device-managed version of request_resource(). There is usually 1511 * no need to release resources requested by this function explicitly since 1512 * that will be taken care of when the device is unbound from its driver. 1513 * If for some reason the resource needs to be released explicitly, because 1514 * of ordering issues for example, drivers must call devm_release_resource() 1515 * rather than the regular release_resource(). 1516 * 1517 * When a conflict is detected between any existing resources and the newly 1518 * requested resource, an error message will be printed. 1519 * 1520 * Returns 0 on success or a negative error code on failure. 1521 */ 1522 int devm_request_resource(struct device *dev, struct resource *root, 1523 struct resource *new) 1524 { 1525 struct resource *conflict, **ptr; 1526 1527 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); 1528 if (!ptr) 1529 return -ENOMEM; 1530 1531 *ptr = new; 1532 1533 conflict = request_resource_conflict(root, new); 1534 if (conflict) { 1535 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n", 1536 new, conflict->name, conflict); 1537 devres_free(ptr); 1538 return -EBUSY; 1539 } 1540 1541 devres_add(dev, ptr); 1542 return 0; 1543 } 1544 EXPORT_SYMBOL(devm_request_resource); 1545 1546 static int devm_resource_match(struct device *dev, void *res, void *data) 1547 { 1548 struct resource **ptr = res; 1549 1550 return *ptr == data; 1551 } 1552 1553 /** 1554 * devm_release_resource() - release a previously requested resource 1555 * @dev: device for which to release the resource 1556 * @new: descriptor of the resource to release 1557 * 1558 * Releases a resource previously requested using devm_request_resource(). 1559 */ 1560 void devm_release_resource(struct device *dev, struct resource *new) 1561 { 1562 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, 1563 new)); 1564 } 1565 EXPORT_SYMBOL(devm_release_resource); 1566 1567 struct region_devres { 1568 struct resource *parent; 1569 resource_size_t start; 1570 resource_size_t n; 1571 }; 1572 1573 static void devm_region_release(struct device *dev, void *res) 1574 { 1575 struct region_devres *this = res; 1576 1577 __release_region(this->parent, this->start, this->n); 1578 } 1579 1580 static int devm_region_match(struct device *dev, void *res, void *match_data) 1581 { 1582 struct region_devres *this = res, *match = match_data; 1583 1584 return this->parent == match->parent && 1585 this->start == match->start && this->n == match->n; 1586 } 1587 1588 struct resource * 1589 __devm_request_region(struct device *dev, struct resource *parent, 1590 resource_size_t start, resource_size_t n, const char *name) 1591 { 1592 struct region_devres *dr = NULL; 1593 struct resource *res; 1594 1595 dr = devres_alloc(devm_region_release, sizeof(struct region_devres), 1596 GFP_KERNEL); 1597 if (!dr) 1598 return NULL; 1599 1600 dr->parent = parent; 1601 dr->start = start; 1602 dr->n = n; 1603 1604 res = __request_region(parent, start, n, name, 0); 1605 if (res) 1606 devres_add(dev, dr); 1607 else 1608 devres_free(dr); 1609 1610 return res; 1611 } 1612 EXPORT_SYMBOL(__devm_request_region); 1613 1614 void __devm_release_region(struct device *dev, struct resource *parent, 1615 resource_size_t start, resource_size_t n) 1616 { 1617 struct region_devres match_data = { parent, start, n }; 1618 1619 __release_region(parent, start, n); 1620 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, 1621 &match_data)); 1622 } 1623 EXPORT_SYMBOL(__devm_release_region); 1624 1625 /* 1626 * Reserve I/O ports or memory based on "reserve=" kernel parameter. 1627 */ 1628 #define MAXRESERVE 4 1629 static int __init reserve_setup(char *str) 1630 { 1631 static int reserved; 1632 static struct resource reserve[MAXRESERVE]; 1633 1634 for (;;) { 1635 unsigned int io_start, io_num; 1636 int x = reserved; 1637 struct resource *parent; 1638 1639 if (get_option(&str, &io_start) != 2) 1640 break; 1641 if (get_option(&str, &io_num) == 0) 1642 break; 1643 if (x < MAXRESERVE) { 1644 struct resource *res = reserve + x; 1645 1646 /* 1647 * If the region starts below 0x10000, we assume it's 1648 * I/O port space; otherwise assume it's memory. 1649 */ 1650 if (io_start < 0x10000) { 1651 res->flags = IORESOURCE_IO; 1652 parent = &ioport_resource; 1653 } else { 1654 res->flags = IORESOURCE_MEM; 1655 parent = &iomem_resource; 1656 } 1657 res->name = "reserved"; 1658 res->start = io_start; 1659 res->end = io_start + io_num - 1; 1660 res->flags |= IORESOURCE_BUSY; 1661 res->desc = IORES_DESC_NONE; 1662 res->child = NULL; 1663 if (request_resource(parent, res) == 0) 1664 reserved = x+1; 1665 } 1666 } 1667 return 1; 1668 } 1669 __setup("reserve=", reserve_setup); 1670 1671 /* 1672 * Check if the requested addr and size spans more than any slot in the 1673 * iomem resource tree. 1674 */ 1675 int iomem_map_sanity_check(resource_size_t addr, unsigned long size) 1676 { 1677 struct resource *p = &iomem_resource; 1678 int err = 0; 1679 loff_t l; 1680 1681 read_lock(&resource_lock); 1682 for (p = p->child; p ; p = r_next(NULL, p, &l)) { 1683 /* 1684 * We can probably skip the resources without 1685 * IORESOURCE_IO attribute? 1686 */ 1687 if (p->start >= addr + size) 1688 continue; 1689 if (p->end < addr) 1690 continue; 1691 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && 1692 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) 1693 continue; 1694 /* 1695 * if a resource is "BUSY", it's not a hardware resource 1696 * but a driver mapping of such a resource; we don't want 1697 * to warn for those; some drivers legitimately map only 1698 * partial hardware resources. (example: vesafb) 1699 */ 1700 if (p->flags & IORESOURCE_BUSY) 1701 continue; 1702 1703 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n", 1704 (unsigned long long)addr, 1705 (unsigned long long)(addr + size - 1), 1706 p->name, p); 1707 err = -1; 1708 break; 1709 } 1710 read_unlock(&resource_lock); 1711 1712 return err; 1713 } 1714 1715 #ifdef CONFIG_STRICT_DEVMEM 1716 static int strict_iomem_checks = 1; 1717 #else 1718 static int strict_iomem_checks; 1719 #endif 1720 1721 /* 1722 * Check if an address is exclusive to the kernel and must not be mapped to 1723 * user space, for example, via /dev/mem. 1724 * 1725 * Returns true if exclusive to the kernel, otherwise returns false. 1726 */ 1727 bool iomem_is_exclusive(u64 addr) 1728 { 1729 const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM | 1730 IORESOURCE_EXCLUSIVE; 1731 bool skip_children = false, err = false; 1732 int size = PAGE_SIZE; 1733 struct resource *p; 1734 1735 addr = addr & PAGE_MASK; 1736 1737 read_lock(&resource_lock); 1738 for_each_resource(&iomem_resource, p, skip_children) { 1739 if (p->start >= addr + size) 1740 break; 1741 if (p->end < addr) { 1742 skip_children = true; 1743 continue; 1744 } 1745 skip_children = false; 1746 1747 /* 1748 * IORESOURCE_SYSTEM_RAM resources are exclusive if 1749 * IORESOURCE_EXCLUSIVE is set, even if they 1750 * are not busy and even if "iomem=relaxed" is set. The 1751 * responsible driver dynamically adds/removes system RAM within 1752 * such an area and uncontrolled access is dangerous. 1753 */ 1754 if ((p->flags & exclusive_system_ram) == exclusive_system_ram) { 1755 err = true; 1756 break; 1757 } 1758 1759 /* 1760 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set 1761 * or CONFIG_IO_STRICT_DEVMEM is enabled and the 1762 * resource is busy. 1763 */ 1764 if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY)) 1765 continue; 1766 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) 1767 || p->flags & IORESOURCE_EXCLUSIVE) { 1768 err = true; 1769 break; 1770 } 1771 } 1772 read_unlock(&resource_lock); 1773 1774 return err; 1775 } 1776 1777 struct resource_entry *resource_list_create_entry(struct resource *res, 1778 size_t extra_size) 1779 { 1780 struct resource_entry *entry; 1781 1782 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL); 1783 if (entry) { 1784 INIT_LIST_HEAD(&entry->node); 1785 entry->res = res ? res : &entry->__res; 1786 } 1787 1788 return entry; 1789 } 1790 EXPORT_SYMBOL(resource_list_create_entry); 1791 1792 void resource_list_free(struct list_head *head) 1793 { 1794 struct resource_entry *entry, *tmp; 1795 1796 list_for_each_entry_safe(entry, tmp, head, node) 1797 resource_list_destroy_entry(entry); 1798 } 1799 EXPORT_SYMBOL(resource_list_free); 1800 1801 #ifdef CONFIG_DEVICE_PRIVATE 1802 static struct resource *__request_free_mem_region(struct device *dev, 1803 struct resource *base, unsigned long size, const char *name) 1804 { 1805 resource_size_t end, addr; 1806 struct resource *res; 1807 struct region_devres *dr = NULL; 1808 1809 size = ALIGN(size, 1UL << PA_SECTION_SHIFT); 1810 end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1); 1811 addr = end - size + 1UL; 1812 1813 res = alloc_resource(GFP_KERNEL); 1814 if (!res) 1815 return ERR_PTR(-ENOMEM); 1816 1817 if (dev) { 1818 dr = devres_alloc(devm_region_release, 1819 sizeof(struct region_devres), GFP_KERNEL); 1820 if (!dr) { 1821 free_resource(res); 1822 return ERR_PTR(-ENOMEM); 1823 } 1824 } 1825 1826 write_lock(&resource_lock); 1827 for (; addr > size && addr >= base->start; addr -= size) { 1828 if (__region_intersects(addr, size, 0, IORES_DESC_NONE) != 1829 REGION_DISJOINT) 1830 continue; 1831 1832 if (__request_region_locked(res, &iomem_resource, addr, size, 1833 name, 0)) 1834 break; 1835 1836 if (dev) { 1837 dr->parent = &iomem_resource; 1838 dr->start = addr; 1839 dr->n = size; 1840 devres_add(dev, dr); 1841 } 1842 1843 res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; 1844 write_unlock(&resource_lock); 1845 1846 /* 1847 * A driver is claiming this region so revoke any mappings. 1848 */ 1849 revoke_iomem(res); 1850 return res; 1851 } 1852 write_unlock(&resource_lock); 1853 1854 free_resource(res); 1855 if (dr) 1856 devres_free(dr); 1857 1858 return ERR_PTR(-ERANGE); 1859 } 1860 1861 /** 1862 * devm_request_free_mem_region - find free region for device private memory 1863 * 1864 * @dev: device struct to bind the resource to 1865 * @size: size in bytes of the device memory to add 1866 * @base: resource tree to look in 1867 * 1868 * This function tries to find an empty range of physical address big enough to 1869 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE 1870 * memory, which in turn allocates struct pages. 1871 */ 1872 struct resource *devm_request_free_mem_region(struct device *dev, 1873 struct resource *base, unsigned long size) 1874 { 1875 return __request_free_mem_region(dev, base, size, dev_name(dev)); 1876 } 1877 EXPORT_SYMBOL_GPL(devm_request_free_mem_region); 1878 1879 struct resource *request_free_mem_region(struct resource *base, 1880 unsigned long size, const char *name) 1881 { 1882 return __request_free_mem_region(NULL, base, size, name); 1883 } 1884 EXPORT_SYMBOL_GPL(request_free_mem_region); 1885 1886 #endif /* CONFIG_DEVICE_PRIVATE */ 1887 1888 static int __init strict_iomem(char *str) 1889 { 1890 if (strstr(str, "relaxed")) 1891 strict_iomem_checks = 0; 1892 if (strstr(str, "strict")) 1893 strict_iomem_checks = 1; 1894 return 1; 1895 } 1896 1897 static int iomem_fs_init_fs_context(struct fs_context *fc) 1898 { 1899 return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM; 1900 } 1901 1902 static struct file_system_type iomem_fs_type = { 1903 .name = "iomem", 1904 .owner = THIS_MODULE, 1905 .init_fs_context = iomem_fs_init_fs_context, 1906 .kill_sb = kill_anon_super, 1907 }; 1908 1909 static int __init iomem_init_inode(void) 1910 { 1911 static struct vfsmount *iomem_vfs_mount; 1912 static int iomem_fs_cnt; 1913 struct inode *inode; 1914 int rc; 1915 1916 rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt); 1917 if (rc < 0) { 1918 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc); 1919 return rc; 1920 } 1921 1922 inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb); 1923 if (IS_ERR(inode)) { 1924 rc = PTR_ERR(inode); 1925 pr_err("Cannot allocate inode for iomem: %d\n", rc); 1926 simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt); 1927 return rc; 1928 } 1929 1930 /* 1931 * Publish iomem revocation inode initialized. 1932 * Pairs with smp_load_acquire() in revoke_iomem(). 1933 */ 1934 smp_store_release(&iomem_inode, inode); 1935 1936 return 0; 1937 } 1938 1939 fs_initcall(iomem_init_inode); 1940 1941 __setup("iomem=", strict_iomem); 1942