kernel/resource.c

   1 /*
   2  *      linux/kernel/resource.c
   3  *
   4  * Copyright (C) 1999   Linus Torvalds
   5  * Copyright (C) 1999   Martin Mares <mj@ucw.cz>
   6  *
   7  * Arbitrary resource management.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/export.h>
  13 #include <linux/errno.h>
  14 #include <linux/ioport.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/fs.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/sched.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/device.h>
  23 #include <linux/pfn.h>
  24 #include <linux/mm.h>
  25 #include <linux/resource_ext.h>
  26 #include <asm/io.h>
  27
  28
  29 struct resource ioport_resource = {
  30         .name   = "PCI IO",
  31         .start  = 0,
  32         .end    = IO_SPACE_LIMIT,
  33         .flags  = IORESOURCE_IO,
  34 };
  35 EXPORT_SYMBOL(ioport_resource);
  36
  37 struct resource iomem_resource = {
  38         .name   = "PCI mem",
  39         .start  = 0,
  40         .end    = -1,
  41         .flags  = IORESOURCE_MEM,
  42 };
  43 EXPORT_SYMBOL(iomem_resource);
  44
  45 /* constraints to be met while allocating resources */
  46 struct resource_constraint {
  47         resource_size_t min, max, align;
  48         resource_size_t (*alignf)(void *, const struct resource *,
  49                         resource_size_t, resource_size_t);
  50         void *alignf_data;
  51 };
  52
  53 static DEFINE_RWLOCK(resource_lock);
  54
  55 /*
  56  * For memory hotplug, there is no way to free resource entries allocated
  57  * by boot mem after the system is up. So for reusing the resource entry
  58  * we need to remember the resource.
  59  */
  60 static struct resource *bootmem_resource_free;
  61 static DEFINE_SPINLOCK(bootmem_resource_lock);
  62
  63 static struct resource *next_resource(struct resource *p, bool sibling_only)
  64 {
  65         /* Caller wants to traverse through siblings only */
  66         if (sibling_only)
  67                 return p->sibling;
  68
  69         if (p->child)
  70                 return p->child;
  71         while (!p->sibling && p->parent)
  72                 p = p->parent;
  73         return p->sibling;
  74 }
  75
  76 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  77 {
  78         struct resource *p = v;
  79         (*pos)++;
  80         return (void *)next_resource(p, false);
  81 }
  82
  83 #ifdef CONFIG_PROC_FS
  84
  85 enum { MAX_IORES_LEVEL = 5 };
  86
  87 static void *r_start(struct seq_file *m, loff_t *pos)
  88         __acquires(resource_lock)
  89 {
  90         struct resource *p = m->private;
  91         loff_t l = 0;
  92         read_lock(&resource_lock);
  93         for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  94                 ;
  95         return p;
  96 }
  97
  98 static void r_stop(struct seq_file *m, void *v)
  99         __releases(resource_lock)
 100 {
 101         read_unlock(&resource_lock);
 102 }
 103
 104 static int r_show(struct seq_file *m, void *v)
 105 {
 106         struct resource *root = m->private;
 107         struct resource *r = v, *p;
 108         unsigned long long start, end;
 109         int width = root->end < 0x10000 ? 4 : 8;
 110         int depth;
 111
 112         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
 113                 if (p->parent == root)
 114                         break;
 115
 116         if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
 117                 start = r->start;
 118                 end = r->end;
 119         } else {
 120                 start = end = 0;
 121         }
 122
 123         seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
 124                         depth * 2, "",
 125                         width, start,
 126                         width, end,
 127                         r->name ? r->name : "<BAD>");
 128         return 0;
 129 }
 130
 131 static const struct seq_operations resource_op = {
 132         .start  = r_start,
 133         .next   = r_next,
 134         .stop   = r_stop,
 135         .show   = r_show,
 136 };
 137
 138 static int ioports_open(struct inode *inode, struct file *file)
 139 {
 140         int res = seq_open(file, &resource_op);
 141         if (!res) {
 142                 struct seq_file *m = file->private_data;
 143                 m->private = &ioport_resource;
 144         }
 145         return res;
 146 }
 147
 148 static int iomem_open(struct inode *inode, struct file *file)
 149 {
 150         int res = seq_open(file, &resource_op);
 151         if (!res) {
 152                 struct seq_file *m = file->private_data;
 153                 m->private = &iomem_resource;
 154         }
 155         return res;
 156 }
 157
 158 static const struct file_operations proc_ioports_operations = {
 159         .open           = ioports_open,
 160         .read           = seq_read,
 161         .llseek         = seq_lseek,
 162         .release        = seq_release,
 163 };
 164
 165 static const struct file_operations proc_iomem_operations = {
 166         .open           = iomem_open,
 167         .read           = seq_read,
 168         .llseek         = seq_lseek,
 169         .release        = seq_release,
 170 };
 171
 172 static int __init ioresources_init(void)
 173 {
 174         proc_create("ioports", 0, NULL, &proc_ioports_operations);
 175         proc_create("iomem", 0, NULL, &proc_iomem_operations);
 176         return 0;
 177 }
 178 __initcall(ioresources_init);
 179
 180 #endif /* CONFIG_PROC_FS */
 181
 182 static void free_resource(struct resource *res)
 183 {
 184         if (!res)
 185                 return;
 186
 187         if (!PageSlab(virt_to_head_page(res))) {
 188                 spin_lock(&bootmem_resource_lock);
 189                 res->sibling = bootmem_resource_free;
 190                 bootmem_resource_free = res;
 191                 spin_unlock(&bootmem_resource_lock);
 192         } else {
 193                 kfree(res);
 194         }
 195 }
 196
 197 static struct resource *alloc_resource(gfp_t flags)
 198 {
 199         struct resource *res = NULL;
 200
 201         spin_lock(&bootmem_resource_lock);
 202         if (bootmem_resource_free) {
 203                 res = bootmem_resource_free;
 204                 bootmem_resource_free = res->sibling;
 205         }
 206         spin_unlock(&bootmem_resource_lock);
 207
 208         if (res)
 209                 memset(res, 0, sizeof(struct resource));
 210         else
 211                 res = kzalloc(sizeof(struct resource), flags);
 212
 213         return res;
 214 }
 215
 216 /* Return the conflict entry if you can't request it */
 217 static struct resource * __request_resource(struct resource *root, struct resource *new)
 218 {
 219         resource_size_t start = new->start;
 220         resource_size_t end = new->end;
 221         struct resource *tmp, **p;
 222
 223         if (end < start)
 224                 return root;
 225         if (start < root->start)
 226                 return root;
 227         if (end > root->end)
 228                 return root;
 229         p = &root->child;
 230         for (;;) {
 231                 tmp = *p;
 232                 if (!tmp || tmp->start > end) {
 233                         new->sibling = tmp;
 234                         *p = new;
 235                         new->parent = root;
 236                         return NULL;
 237                 }
 238                 p = &tmp->sibling;
 239                 if (tmp->end < start)
 240                         continue;
 241                 return tmp;
 242         }
 243 }
 244
 245 static int __release_resource(struct resource *old, bool release_child)
 246 {
 247         struct resource *tmp, **p, *chd;
 248
 249         p = &old->parent->child;
 250         for (;;) {
 251                 tmp = *p;
 252                 if (!tmp)
 253                         break;
 254                 if (tmp == old) {
 255                         if (release_child || !(tmp->child)) {
 256                                 *p = tmp->sibling;
 257                         } else {
 258                                 for (chd = tmp->child;; chd = chd->sibling) {
 259                                         chd->parent = tmp->parent;
 260                                         if (!(chd->sibling))
 261                                                 break;
 262                                 }
 263                                 *p = tmp->child;
 264                                 chd->sibling = tmp->sibling;
 265                         }
 266                         old->parent = NULL;
 267                         return 0;
 268                 }
 269                 p = &tmp->sibling;
 270         }
 271         return -EINVAL;
 272 }
 273
 274 static void __release_child_resources(struct resource *r)
 275 {
 276         struct resource *tmp, *p;
 277         resource_size_t size;
 278
 279         p = r->child;
 280         r->child = NULL;
 281         while (p) {
 282                 tmp = p;
 283                 p = p->sibling;
 284
 285                 tmp->parent = NULL;
 286                 tmp->sibling = NULL;
 287                 __release_child_resources(tmp);
 288
 289                 printk(KERN_DEBUG "release child resource %pR\n", tmp);
 290                 /* need to restore size, and keep flags */
 291                 size = resource_size(tmp);
 292                 tmp->start = 0;
 293                 tmp->end = size - 1;
 294         }
 295 }
 296
 297 void release_child_resources(struct resource *r)
 298 {
 299         write_lock(&resource_lock);
 300         __release_child_resources(r);
 301         write_unlock(&resource_lock);
 302 }
 303
 304 /**
 305  * request_resource_conflict - request and reserve an I/O or memory resource
 306  * @root: root resource descriptor
 307  * @new: resource descriptor desired by caller
 308  *
 309  * Returns 0 for success, conflict resource on error.
 310  */
 311 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
 312 {
 313         struct resource *conflict;
 314
 315         write_lock(&resource_lock);
 316         conflict = __request_resource(root, new);
 317         write_unlock(&resource_lock);
 318         return conflict;
 319 }
 320
 321 /**
 322  * request_resource - request and reserve an I/O or memory resource
 323  * @root: root resource descriptor
 324  * @new: resource descriptor desired by caller
 325  *
 326  * Returns 0 for success, negative error code on error.
 327  */
 328 int request_resource(struct resource *root, struct resource *new)
 329 {
 330         struct resource *conflict;
 331
 332         conflict = request_resource_conflict(root, new);
 333         return conflict ? -EBUSY : 0;
 334 }
 335
 336 EXPORT_SYMBOL(request_resource);
 337
 338 /**
 339  * release_resource - release a previously reserved resource
 340  * @old: resource pointer
 341  */
 342 int release_resource(struct resource *old)
 343 {
 344         int retval;
 345
 346         write_lock(&resource_lock);
 347         retval = __release_resource(old, true);
 348         write_unlock(&resource_lock);
 349         return retval;
 350 }
 351
 352 EXPORT_SYMBOL(release_resource);
 353
 354 /*
 355  * Finds the lowest iomem resource existing within [res->start.res->end).
 356  * The caller must specify res->start, res->end, res->flags, and optionally
 357  * desc.  If found, returns 0, res is overwritten, if not found, returns -1.
 358  * This function walks the whole tree and not just first level children until
 359  * and unless first_level_children_only is true.
 360  */
 361 static int find_next_iomem_res(struct resource *res, unsigned long desc,
 362                                bool first_level_children_only)
 363 {
 364         resource_size_t start, end;
 365         struct resource *p;
 366         bool sibling_only = false;
 367
 368         BUG_ON(!res);
 369
 370         start = res->start;
 371         end = res->end;
 372         BUG_ON(start >= end);
 373
 374         if (first_level_children_only)
 375                 sibling_only = true;
 376
 377         read_lock(&resource_lock);
 378
 379         for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
 380                 if ((p->flags & res->flags) != res->flags)
 381                         continue;
 382                 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
 383                         continue;
 384                 if (p->start > end) {
 385                         p = NULL;
 386                         break;
 387                 }
 388                 if ((p->end >= start) && (p->start < end))
 389                         break;
 390         }
 391
 392         read_unlock(&resource_lock);
 393         if (!p)
 394                 return -1;
 395         /* copy data */
 396         if (res->start < p->start)
 397                 res->start = p->start;
 398         if (res->end > p->end)
 399                 res->end = p->end;
 400         res->flags = p->flags;
 401         res->desc = p->desc;
 402         return 0;
 403 }
 404
 405 static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
 406                                  bool first_level_children_only,
 407                                  void *arg,
 408                                  int (*func)(struct resource *, void *))
 409 {
 410         u64 orig_end = res->end;
 411         int ret = -1;
 412
 413         while ((res->start < res->end) &&
 414                !find_next_iomem_res(res, desc, first_level_children_only)) {
 415                 ret = (*func)(res, arg);
 416                 if (ret)
 417                         break;
 418
 419                 res->start = res->end + 1;
 420                 res->end = orig_end;
 421         }
 422
 423         return ret;
 424 }
 425
 426 /*
 427  * Walks through iomem resources and calls func() with matching resource
 428  * ranges. This walks through whole tree and not just first level children.
 429  * All the memory ranges which overlap start,end and also match flags and
 430  * desc are valid candidates.
 431  *
 432  * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
 433  * @flags: I/O resource flags
 434  * @start: start addr
 435  * @end: end addr
 436  *
 437  * NOTE: For a new descriptor search, define a new IORES_DESC in
 438  * <linux/ioport.h> and set it in 'desc' of a target resource entry.
 439  */
 440 int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
 441                 u64 end, void *arg, int (*func)(struct resource *, void *))
 442 {
 443         struct resource res;
 444
 445         res.start = start;
 446         res.end = end;
 447         res.flags = flags;
 448
 449         return __walk_iomem_res_desc(&res, desc, false, arg, func);
 450 }
 451
 452 /*
 453  * This function calls the @func callback against all memory ranges of type
 454  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
 455  * Now, this function is only for System RAM, it deals with full ranges and
 456  * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
 457  * ranges.
 458  */
 459 int walk_system_ram_res(u64 start, u64 end, void *arg,
 460                                 int (*func)(struct resource *, void *))
 461 {
 462         struct resource res;
 463
 464         res.start = start;
 465         res.end = end;
 466         res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 467
 468         return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
 469                                      arg, func);
 470 }
 471
 472 /*
 473  * This function calls the @func callback against all memory ranges, which
 474  * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 475  */
 476 int walk_mem_res(u64 start, u64 end, void *arg,
 477                  int (*func)(struct resource *, void *))
 478 {
 479         struct resource res;
 480
 481         res.start = start;
 482         res.end = end;
 483         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 484
 485         return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
 486                                      arg, func);
 487 }
 488
 489 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 490
 491 /*
 492  * This function calls the @func callback against all memory ranges of type
 493  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
 494  * It is to be used only for System RAM.
 495  */
 496 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 497                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 498 {
 499         struct resource res;
 500         unsigned long pfn, end_pfn;
 501         u64 orig_end;
 502         int ret = -1;
 503
 504         res.start = (u64) start_pfn << PAGE_SHIFT;
 505         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 506         res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 507         orig_end = res.end;
 508         while ((res.start < res.end) &&
 509                 (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
 510                 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 511                 end_pfn = (res.end + 1) >> PAGE_SHIFT;
 512                 if (end_pfn > pfn)
 513                         ret = (*func)(pfn, end_pfn - pfn, arg);
 514                 if (ret)
 515                         break;
 516                 res.start = res.end + 1;
 517                 res.end = orig_end;
 518         }
 519         return ret;
 520 }
 521
 522 #endif
 523
 524 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 525 {
 526         return 1;
 527 }
 528
 529 /*
 530  * This generic page_is_ram() returns true if specified address is
 531  * registered as System RAM in iomem_resource list.
 532  */
 533 int __weak page_is_ram(unsigned long pfn)
 534 {
 535         return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 536 }
 537 EXPORT_SYMBOL_GPL(page_is_ram);
 538
 539 /**
 540  * region_intersects() - determine intersection of region with known resources
 541  * @start: region start address
 542  * @size: size of region
 543  * @flags: flags of resource (in iomem_resource)
 544  * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
 545  *
 546  * Check if the specified region partially overlaps or fully eclipses a
 547  * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
 548  * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
 549  * return REGION_MIXED if the region overlaps @flags/@desc and another
 550  * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
 551  * and no other defined resource. Note that REGION_INTERSECTS is also
 552  * returned in the case when the specified region overlaps RAM and undefined
 553  * memory holes.
 554  *
 555  * region_intersect() is used by memory remapping functions to ensure
 556  * the user is not remapping RAM and is a vast speed up over walking
 557  * through the resource table page by page.
 558  */
 559 int region_intersects(resource_size_t start, size_t size, unsigned long flags,
 560                       unsigned long desc)
 561 {
 562         resource_size_t end = start + size - 1;
 563         int type = 0; int other = 0;
 564         struct resource *p;
 565
 566         read_lock(&resource_lock);
 567         for (p = iomem_resource.child; p ; p = p->sibling) {
 568                 bool is_type = (((p->flags & flags) == flags) &&
 569                                 ((desc == IORES_DESC_NONE) ||
 570                                  (desc == p->desc)));
 571
 572                 if (start >= p->start && start <= p->end)
 573                         is_type ? type++ : other++;
 574                 if (end >= p->start && end <= p->end)
 575                         is_type ? type++ : other++;
 576                 if (p->start >= start && p->end <= end)
 577                         is_type ? type++ : other++;
 578         }
 579         read_unlock(&resource_lock);
 580
 581         if (other == 0)
 582                 return type ? REGION_INTERSECTS : REGION_DISJOINT;
 583
 584         if (type)
 585                 return REGION_MIXED;
 586
 587         return REGION_DISJOINT;
 588 }
 589 EXPORT_SYMBOL_GPL(region_intersects);
 590
 591 void __weak arch_remove_reservations(struct resource *avail)
 592 {
 593 }
 594
 595 static resource_size_t simple_align_resource(void *data,
 596                                              const struct resource *avail,
 597                                              resource_size_t size,
 598                                              resource_size_t align)
 599 {
 600         return avail->start;
 601 }
 602
 603 static void resource_clip(struct resource *res, resource_size_t min,
 604                           resource_size_t max)
 605 {
 606         if (res->start < min)
 607                 res->start = min;
 608         if (res->end > max)
 609                 res->end = max;
 610 }
 611
 612 /*
 613  * Find empty slot in the resource tree with the given range and
 614  * alignment constraints
 615  */
 616 static int __find_resource(struct resource *root, struct resource *old,
 617                          struct resource *new,
 618                          resource_size_t  size,
 619                          struct resource_constraint *constraint)
 620 {
 621         struct resource *this = root->child;
 622         struct resource tmp = *new, avail, alloc;
 623
 624         tmp.start = root->start;
 625         /*
 626          * Skip past an allocated resource that starts at 0, since the assignment
 627          * of this->start - 1 to tmp->end below would cause an underflow.
 628          */
 629         if (this && this->start == root->start) {
 630                 tmp.start = (this == old) ? old->start : this->end + 1;
 631                 this = this->sibling;
 632         }
 633         for(;;) {
 634                 if (this)
 635                         tmp.end = (this == old) ?  this->end : this->start - 1;
 636                 else
 637                         tmp.end = root->end;
 638
 639                 if (tmp.end < tmp.start)
 640                         goto next;
 641
 642                 resource_clip(&tmp, constraint->min, constraint->max);
 643                 arch_remove_reservations(&tmp);
 644
 645                 /* Check for overflow after ALIGN() */
 646                 avail.start = ALIGN(tmp.start, constraint->align);
 647                 avail.end = tmp.end;
 648                 avail.flags = new->flags & ~IORESOURCE_UNSET;
 649                 if (avail.start >= tmp.start) {
 650                         alloc.flags = avail.flags;
 651                         alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 652                                         size, constraint->align);
 653                         alloc.end = alloc.start + size - 1;
 654                         if (resource_contains(&avail, &alloc)) {
 655                                 new->start = alloc.start;
 656                                 new->end = alloc.end;
 657                                 return 0;
 658                         }
 659                 }
 660
 661 next:           if (!this || this->end == root->end)
 662                         break;
 663
 664                 if (this != old)
 665                         tmp.start = this->end + 1;
 666                 this = this->sibling;
 667         }
 668         return -EBUSY;
 669 }
 670
 671 /*
 672  * Find empty slot in the resource tree given range and alignment.
 673  */
 674 static int find_resource(struct resource *root, struct resource *new,
 675                         resource_size_t size,
 676                         struct resource_constraint  *constraint)
 677 {
 678         return  __find_resource(root, NULL, new, size, constraint);
 679 }
 680
 681 /**
 682  * reallocate_resource - allocate a slot in the resource tree given range & alignment.
 683  *      The resource will be relocated if the new size cannot be reallocated in the
 684  *      current location.
 685  *
 686  * @root: root resource descriptor
 687  * @old:  resource descriptor desired by caller
 688  * @newsize: new size of the resource descriptor
 689  * @constraint: the size and alignment constraints to be met.
 690  */
 691 static int reallocate_resource(struct resource *root, struct resource *old,
 692                         resource_size_t newsize,
 693                         struct resource_constraint  *constraint)
 694 {
 695         int err=0;
 696         struct resource new = *old;
 697         struct resource *conflict;
 698
 699         write_lock(&resource_lock);
 700
 701         if ((err = __find_resource(root, old, &new, newsize, constraint)))
 702                 goto out;
 703
 704         if (resource_contains(&new, old)) {
 705                 old->start = new.start;
 706                 old->end = new.end;
 707                 goto out;
 708         }
 709
 710         if (old->child) {
 711                 err = -EBUSY;
 712                 goto out;
 713         }
 714
 715         if (resource_contains(old, &new)) {
 716                 old->start = new.start;
 717                 old->end = new.end;
 718         } else {
 719                 __release_resource(old, true);
 720                 *old = new;
 721                 conflict = __request_resource(root, old);
 722                 BUG_ON(conflict);
 723         }
 724 out:
 725         write_unlock(&resource_lock);
 726         return err;
 727 }
 728
 729
 730 /**
 731  * allocate_resource - allocate empty slot in the resource tree given range & alignment.
 732  *      The resource will be reallocated with a new size if it was already allocated
 733  * @root: root resource descriptor
 734  * @new: resource descriptor desired by caller
 735  * @size: requested resource region size
 736  * @min: minimum boundary to allocate
 737  * @max: maximum boundary to allocate
 738  * @align: alignment requested, in bytes
 739  * @alignf: alignment function, optional, called if not NULL
 740  * @alignf_data: arbitrary data to pass to the @alignf function
 741  */
 742 int allocate_resource(struct resource *root, struct resource *new,
 743                       resource_size_t size, resource_size_t min,
 744                       resource_size_t max, resource_size_t align,
 745                       resource_size_t (*alignf)(void *,
 746                                                 const struct resource *,
 747                                                 resource_size_t,
 748                                                 resource_size_t),
 749                       void *alignf_data)
 750 {
 751         int err;
 752         struct resource_constraint constraint;
 753
 754         if (!alignf)
 755                 alignf = simple_align_resource;
 756
 757         constraint.min = min;
 758         constraint.max = max;
 759         constraint.align = align;
 760         constraint.alignf = alignf;
 761         constraint.alignf_data = alignf_data;
 762
 763         if ( new->parent ) {
 764                 /* resource is already allocated, try reallocating with
 765                    the new constraints */
 766                 return reallocate_resource(root, new, size, &constraint);
 767         }
 768
 769         write_lock(&resource_lock);
 770         err = find_resource(root, new, size, &constraint);
 771         if (err >= 0 && __request_resource(root, new))
 772                 err = -EBUSY;
 773         write_unlock(&resource_lock);
 774         return err;
 775 }
 776
 777 EXPORT_SYMBOL(allocate_resource);
 778
 779 /**
 780  * lookup_resource - find an existing resource by a resource start address
 781  * @root: root resource descriptor
 782  * @start: resource start address
 783  *
 784  * Returns a pointer to the resource if found, NULL otherwise
 785  */
 786 struct resource *lookup_resource(struct resource *root, resource_size_t start)
 787 {
 788         struct resource *res;
 789
 790         read_lock(&resource_lock);
 791         for (res = root->child; res; res = res->sibling) {
 792                 if (res->start == start)
 793                         break;
 794         }
 795         read_unlock(&resource_lock);
 796
 797         return res;
 798 }
 799
 800 /*
 801  * Insert a resource into the resource tree. If successful, return NULL,
 802  * otherwise return the conflicting resource (compare to __request_resource())
 803  */
 804 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 805 {
 806         struct resource *first, *next;
 807
 808         for (;; parent = first) {
 809                 first = __request_resource(parent, new);
 810                 if (!first)
 811                         return first;
 812
 813                 if (first == parent)
 814                         return first;
 815                 if (WARN_ON(first == new))      /* duplicated insertion */
 816                         return first;
 817
 818                 if ((first->start > new->start) || (first->end < new->end))
 819                         break;
 820                 if ((first->start == new->start) && (first->end == new->end))
 821                         break;
 822         }
 823
 824         for (next = first; ; next = next->sibling) {
 825                 /* Partial overlap? Bad, and unfixable */
 826                 if (next->start < new->start || next->end > new->end)
 827                         return next;
 828                 if (!next->sibling)
 829                         break;
 830                 if (next->sibling->start > new->end)
 831                         break;
 832         }
 833
 834         new->parent = parent;
 835         new->sibling = next->sibling;
 836         new->child = first;
 837
 838         next->sibling = NULL;
 839         for (next = first; next; next = next->sibling)
 840                 next->parent = new;
 841
 842         if (parent->child == first) {
 843                 parent->child = new;
 844         } else {
 845                 next = parent->child;
 846                 while (next->sibling != first)
 847                         next = next->sibling;
 848                 next->sibling = new;
 849         }
 850         return NULL;
 851 }
 852
 853 /**
 854  * insert_resource_conflict - Inserts resource in the resource tree
 855  * @parent: parent of the new resource
 856  * @new: new resource to insert
 857  *
 858  * Returns 0 on success, conflict resource if the resource can't be inserted.
 859  *
 860  * This function is equivalent to request_resource_conflict when no conflict
 861  * happens. If a conflict happens, and the conflicting resources
 862  * entirely fit within the range of the new resource, then the new
 863  * resource is inserted and the conflicting resources become children of
 864  * the new resource.
 865  *
 866  * This function is intended for producers of resources, such as FW modules
 867  * and bus drivers.
 868  */
 869 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 870 {
 871         struct resource *conflict;
 872
 873         write_lock(&resource_lock);
 874         conflict = __insert_resource(parent, new);
 875         write_unlock(&resource_lock);
 876         return conflict;
 877 }
 878
 879 /**
 880  * insert_resource - Inserts a resource in the resource tree
 881  * @parent: parent of the new resource
 882  * @new: new resource to insert
 883  *
 884  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 885  *
 886  * This function is intended for producers of resources, such as FW modules
 887  * and bus drivers.
 888  */
 889 int insert_resource(struct resource *parent, struct resource *new)
 890 {
 891         struct resource *conflict;
 892
 893         conflict = insert_resource_conflict(parent, new);
 894         return conflict ? -EBUSY : 0;
 895 }
 896 EXPORT_SYMBOL_GPL(insert_resource);
 897
 898 /**
 899  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 900  * @root: root resource descriptor
 901  * @new: new resource to insert
 902  *
 903  * Insert a resource into the resource tree, possibly expanding it in order
 904  * to make it encompass any conflicting resources.
 905  */
 906 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 907 {
 908         if (new->parent)
 909                 return;
 910
 911         write_lock(&resource_lock);
 912         for (;;) {
 913                 struct resource *conflict;
 914
 915                 conflict = __insert_resource(root, new);
 916                 if (!conflict)
 917                         break;
 918                 if (conflict == root)
 919                         break;
 920
 921                 /* Ok, expand resource to cover the conflict, then try again .. */
 922                 if (conflict->start < new->start)
 923                         new->start = conflict->start;
 924                 if (conflict->end > new->end)
 925                         new->end = conflict->end;
 926
 927                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 928         }
 929         write_unlock(&resource_lock);
 930 }
 931
 932 /**
 933  * remove_resource - Remove a resource in the resource tree
 934  * @old: resource to remove
 935  *
 936  * Returns 0 on success, -EINVAL if the resource is not valid.
 937  *
 938  * This function removes a resource previously inserted by insert_resource()
 939  * or insert_resource_conflict(), and moves the children (if any) up to
 940  * where they were before.  insert_resource() and insert_resource_conflict()
 941  * insert a new resource, and move any conflicting resources down to the
 942  * children of the new resource.
 943  *
 944  * insert_resource(), insert_resource_conflict() and remove_resource() are
 945  * intended for producers of resources, such as FW modules and bus drivers.
 946  */
 947 int remove_resource(struct resource *old)
 948 {
 949         int retval;
 950
 951         write_lock(&resource_lock);
 952         retval = __release_resource(old, false);
 953         write_unlock(&resource_lock);
 954         return retval;
 955 }
 956 EXPORT_SYMBOL_GPL(remove_resource);
 957
 958 static int __adjust_resource(struct resource *res, resource_size_t start,
 959                                 resource_size_t size)
 960 {
 961         struct resource *tmp, *parent = res->parent;
 962         resource_size_t end = start + size - 1;
 963         int result = -EBUSY;
 964
 965         if (!parent)
 966                 goto skip;
 967
 968         if ((start < parent->start) || (end > parent->end))
 969                 goto out;
 970
 971         if (res->sibling && (res->sibling->start <= end))
 972                 goto out;
 973
 974         tmp = parent->child;
 975         if (tmp != res) {
 976                 while (tmp->sibling != res)
 977                         tmp = tmp->sibling;
 978                 if (start <= tmp->end)
 979                         goto out;
 980         }
 981
 982 skip:
 983         for (tmp = res->child; tmp; tmp = tmp->sibling)
 984                 if ((tmp->start < start) || (tmp->end > end))
 985                         goto out;
 986
 987         res->start = start;
 988         res->end = end;
 989         result = 0;
 990
 991  out:
 992         return result;
 993 }
 994
 995 /**
 996  * adjust_resource - modify a resource's start and size
 997  * @res: resource to modify
 998  * @start: new start value
 999  * @size: new size
1000  *
1001  * Given an existing resource, change its start and size to match the
1002  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
1003  * Existing children of the resource are assumed to be immutable.
1004  */
1005 int adjust_resource(struct resource *res, resource_size_t start,
1006                         resource_size_t size)
1007 {
1008         int result;
1009
1010         write_lock(&resource_lock);
1011         result = __adjust_resource(res, start, size);
1012         write_unlock(&resource_lock);
1013         return result;
1014 }
1015 EXPORT_SYMBOL(adjust_resource);
1016
1017 static void __init __reserve_region_with_split(struct resource *root,
1018                 resource_size_t start, resource_size_t end,
1019                 const char *name)
1020 {
1021         struct resource *parent = root;
1022         struct resource *conflict;
1023         struct resource *res = alloc_resource(GFP_ATOMIC);
1024         struct resource *next_res = NULL;
1025
1026         if (!res)
1027                 return;
1028
1029         res->name = name;
1030         res->start = start;
1031         res->end = end;
1032         res->flags = IORESOURCE_BUSY;
1033         res->desc = IORES_DESC_NONE;
1034
1035         while (1) {
1036
1037                 conflict = __request_resource(parent, res);
1038                 if (!conflict) {
1039                         if (!next_res)
1040                                 break;
1041                         res = next_res;
1042                         next_res = NULL;
1043                         continue;
1044                 }
1045
1046                 /* conflict covered whole area */
1047                 if (conflict->start <= res->start &&
1048                                 conflict->end >= res->end) {
1049                         free_resource(res);
1050                         WARN_ON(next_res);
1051                         break;
1052                 }
1053
1054                 /* failed, split and try again */
1055                 if (conflict->start > res->start) {
1056                         end = res->end;
1057                         res->end = conflict->start - 1;
1058                         if (conflict->end < end) {
1059                                 next_res = alloc_resource(GFP_ATOMIC);
1060                                 if (!next_res) {
1061                                         free_resource(res);
1062                                         break;
1063                                 }
1064                                 next_res->name = name;
1065                                 next_res->start = conflict->end + 1;
1066                                 next_res->end = end;
1067                                 next_res->flags = IORESOURCE_BUSY;
1068                                 next_res->desc = IORES_DESC_NONE;
1069                         }
1070                 } else {
1071                         res->start = conflict->end + 1;
1072                 }
1073         }
1074
1075 }
1076
1077 void __init reserve_region_with_split(struct resource *root,
1078                 resource_size_t start, resource_size_t end,
1079                 const char *name)
1080 {
1081         int abort = 0;
1082
1083         write_lock(&resource_lock);
1084         if (root->start > start || root->end < end) {
1085                 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1086                        (unsigned long long)start, (unsigned long long)end,
1087                        root);
1088                 if (start > root->end || end < root->start)
1089                         abort = 1;
1090                 else {
1091                         if (end > root->end)
1092                                 end = root->end;
1093                         if (start < root->start)
1094                                 start = root->start;
1095                         pr_err("fixing request to [0x%llx-0x%llx]\n",
1096                                (unsigned long long)start,
1097                                (unsigned long long)end);
1098                 }
1099                 dump_stack();
1100         }
1101         if (!abort)
1102                 __reserve_region_with_split(root, start, end, name);
1103         write_unlock(&resource_lock);
1104 }
1105
1106 /**
1107  * resource_alignment - calculate resource's alignment
1108  * @res: resource pointer
1109  *
1110  * Returns alignment on success, 0 (invalid alignment) on failure.
1111  */
1112 resource_size_t resource_alignment(struct resource *res)
1113 {
1114         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1115         case IORESOURCE_SIZEALIGN:
1116                 return resource_size(res);
1117         case IORESOURCE_STARTALIGN:
1118                 return res->start;
1119         default:
1120                 return 0;
1121         }
1122 }
1123
1124 /*
1125  * This is compatibility stuff for IO resources.
1126  *
1127  * Note how this, unlike the above, knows about
1128  * the IO flag meanings (busy etc).
1129  *
1130  * request_region creates a new busy region.
1131  *
1132  * release_region releases a matching busy region.
1133  */
1134
1135 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1136
1137 /**
1138  * __request_region - create a new busy resource region
1139  * @parent: parent resource descriptor
1140  * @start: resource start address
1141  * @n: resource region size
1142  * @name: reserving caller's ID string
1143  * @flags: IO resource flags
1144  */
1145 struct resource * __request_region(struct resource *parent,
1146                                    resource_size_t start, resource_size_t n,
1147                                    const char *name, int flags)
1148 {
1149         DECLARE_WAITQUEUE(wait, current);
1150         struct resource *res = alloc_resource(GFP_KERNEL);
1151
1152         if (!res)
1153                 return NULL;
1154
1155         res->name = name;
1156         res->start = start;
1157         res->end = start + n - 1;
1158
1159         write_lock(&resource_lock);
1160
1161         for (;;) {
1162                 struct resource *conflict;
1163
1164                 res->flags = resource_type(parent) | resource_ext_type(parent);
1165                 res->flags |= IORESOURCE_BUSY | flags;
1166                 res->desc = parent->desc;
1167
1168                 conflict = __request_resource(parent, res);
1169                 if (!conflict)
1170                         break;
1171                 if (conflict != parent) {
1172                         if (!(conflict->flags & IORESOURCE_BUSY)) {
1173                                 parent = conflict;
1174                                 continue;
1175                         }
1176                 }
1177                 if (conflict->flags & flags & IORESOURCE_MUXED) {
1178                         add_wait_queue(&muxed_resource_wait, &wait);
1179                         write_unlock(&resource_lock);
1180                         set_current_state(TASK_UNINTERRUPTIBLE);
1181                         schedule();
1182                         remove_wait_queue(&muxed_resource_wait, &wait);
1183                         write_lock(&resource_lock);
1184                         continue;
1185                 }
1186                 /* Uhhuh, that didn't work out.. */
1187                 free_resource(res);
1188                 res = NULL;
1189                 break;
1190         }
1191         write_unlock(&resource_lock);
1192         return res;
1193 }
1194 EXPORT_SYMBOL(__request_region);
1195
1196 /**
1197  * __release_region - release a previously reserved resource region
1198  * @parent: parent resource descriptor
1199  * @start: resource start address
1200  * @n: resource region size
1201  *
1202  * The described resource region must match a currently busy region.
1203  */
1204 void __release_region(struct resource *parent, resource_size_t start,
1205                         resource_size_t n)
1206 {
1207         struct resource **p;
1208         resource_size_t end;
1209
1210         p = &parent->child;
1211         end = start + n - 1;
1212
1213         write_lock(&resource_lock);
1214
1215         for (;;) {
1216                 struct resource *res = *p;
1217
1218                 if (!res)
1219                         break;
1220                 if (res->start <= start && res->end >= end) {
1221                         if (!(res->flags & IORESOURCE_BUSY)) {
1222                                 p = &res->child;
1223                                 continue;
1224                         }
1225                         if (res->start != start || res->end != end)
1226                                 break;
1227                         *p = res->sibling;
1228                         write_unlock(&resource_lock);
1229                         if (res->flags & IORESOURCE_MUXED)
1230                                 wake_up(&muxed_resource_wait);
1231                         free_resource(res);
1232                         return;
1233                 }
1234                 p = &res->sibling;
1235         }
1236
1237         write_unlock(&resource_lock);
1238
1239         printk(KERN_WARNING "Trying to free nonexistent resource "
1240                 "<%016llx-%016llx>\n", (unsigned long long)start,
1241                 (unsigned long long)end);
1242 }
1243 EXPORT_SYMBOL(__release_region);
1244
1245 #ifdef CONFIG_MEMORY_HOTREMOVE
1246 /**
1247  * release_mem_region_adjustable - release a previously reserved memory region
1248  * @parent: parent resource descriptor
1249  * @start: resource start address
1250  * @size: resource region size
1251  *
1252  * This interface is intended for memory hot-delete.  The requested region
1253  * is released from a currently busy memory resource.  The requested region
1254  * must either match exactly or fit into a single busy resource entry.  In
1255  * the latter case, the remaining resource is adjusted accordingly.
1256  * Existing children of the busy memory resource must be immutable in the
1257  * request.
1258  *
1259  * Note:
1260  * - Additional release conditions, such as overlapping region, can be
1261  *   supported after they are confirmed as valid cases.
1262  * - When a busy memory resource gets split into two entries, the code
1263  *   assumes that all children remain in the lower address entry for
1264  *   simplicity.  Enhance this logic when necessary.
1265  */
1266 int release_mem_region_adjustable(struct resource *parent,
1267                         resource_size_t start, resource_size_t size)
1268 {
1269         struct resource **p;
1270         struct resource *res;
1271         struct resource *new_res;
1272         resource_size_t end;
1273         int ret = -EINVAL;
1274
1275         end = start + size - 1;
1276         if ((start < parent->start) || (end > parent->end))
1277                 return ret;
1278
1279         /* The alloc_resource() result gets checked later */
1280         new_res = alloc_resource(GFP_KERNEL);
1281
1282         p = &parent->child;
1283         write_lock(&resource_lock);
1284
1285         while ((res = *p)) {
1286                 if (res->start >= end)
1287                         break;
1288
1289                 /* look for the next resource if it does not fit into */
1290                 if (res->start > start || res->end < end) {
1291                         p = &res->sibling;
1292                         continue;
1293                 }
1294
1295                 if (!(res->flags & IORESOURCE_MEM))
1296                         break;
1297
1298                 if (!(res->flags & IORESOURCE_BUSY)) {
1299                         p = &res->child;
1300                         continue;
1301                 }
1302
1303                 /* found the target resource; let's adjust accordingly */
1304                 if (res->start == start && res->end == end) {
1305                         /* free the whole entry */
1306                         *p = res->sibling;
1307                         free_resource(res);
1308                         ret = 0;
1309                 } else if (res->start == start && res->end != end) {
1310                         /* adjust the start */
1311                         ret = __adjust_resource(res, end + 1,
1312                                                 res->end - end);
1313                 } else if (res->start != start && res->end == end) {
1314                         /* adjust the end */
1315                         ret = __adjust_resource(res, res->start,
1316                                                 start - res->start);
1317                 } else {
1318                         /* split into two entries */
1319                         if (!new_res) {
1320                                 ret = -ENOMEM;
1321                                 break;
1322                         }
1323                         new_res->name = res->name;
1324                         new_res->start = end + 1;
1325                         new_res->end = res->end;
1326                         new_res->flags = res->flags;
1327                         new_res->desc = res->desc;
1328                         new_res->parent = res->parent;
1329                         new_res->sibling = res->sibling;
1330                         new_res->child = NULL;
1331
1332                         ret = __adjust_resource(res, res->start,
1333                                                 start - res->start);
1334                         if (ret)
1335                                 break;
1336                         res->sibling = new_res;
1337                         new_res = NULL;
1338                 }
1339
1340                 break;
1341         }
1342
1343         write_unlock(&resource_lock);
1344         free_resource(new_res);
1345         return ret;
1346 }
1347 #endif  /* CONFIG_MEMORY_HOTREMOVE */
1348
1349 /*
1350  * Managed region resource
1351  */
1352 static void devm_resource_release(struct device *dev, void *ptr)
1353 {
1354         struct resource **r = ptr;
1355
1356         release_resource(*r);
1357 }
1358
1359 /**
1360  * devm_request_resource() - request and reserve an I/O or memory resource
1361  * @dev: device for which to request the resource
1362  * @root: root of the resource tree from which to request the resource
1363  * @new: descriptor of the resource to request
1364  *
1365  * This is a device-managed version of request_resource(). There is usually
1366  * no need to release resources requested by this function explicitly since
1367  * that will be taken care of when the device is unbound from its driver.
1368  * If for some reason the resource needs to be released explicitly, because
1369  * of ordering issues for example, drivers must call devm_release_resource()
1370  * rather than the regular release_resource().
1371  *
1372  * When a conflict is detected between any existing resources and the newly
1373  * requested resource, an error message will be printed.
1374  *
1375  * Returns 0 on success or a negative error code on failure.
1376  */
1377 int devm_request_resource(struct device *dev, struct resource *root,
1378                           struct resource *new)
1379 {
1380         struct resource *conflict, **ptr;
1381
1382         ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1383         if (!ptr)
1384                 return -ENOMEM;
1385
1386         *ptr = new;
1387
1388         conflict = request_resource_conflict(root, new);
1389         if (conflict) {
1390                 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1391                         new, conflict->name, conflict);
1392                 devres_free(ptr);
1393                 return -EBUSY;
1394         }
1395
1396         devres_add(dev, ptr);
1397         return 0;
1398 }
1399 EXPORT_SYMBOL(devm_request_resource);
1400
1401 static int devm_resource_match(struct device *dev, void *res, void *data)
1402 {
1403         struct resource **ptr = res;
1404
1405         return *ptr == data;
1406 }
1407
1408 /**
1409  * devm_release_resource() - release a previously requested resource
1410  * @dev: device for which to release the resource
1411  * @new: descriptor of the resource to release
1412  *
1413  * Releases a resource previously requested using devm_request_resource().
1414  */
1415 void devm_release_resource(struct device *dev, struct resource *new)
1416 {
1417         WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1418                                new));
1419 }
1420 EXPORT_SYMBOL(devm_release_resource);
1421
1422 struct region_devres {
1423         struct resource *parent;
1424         resource_size_t start;
1425         resource_size_t n;
1426 };
1427
1428 static void devm_region_release(struct device *dev, void *res)
1429 {
1430         struct region_devres *this = res;
1431
1432         __release_region(this->parent, this->start, this->n);
1433 }
1434
1435 static int devm_region_match(struct device *dev, void *res, void *match_data)
1436 {
1437         struct region_devres *this = res, *match = match_data;
1438
1439         return this->parent == match->parent &&
1440                 this->start == match->start && this->n == match->n;
1441 }
1442
1443 struct resource * __devm_request_region(struct device *dev,
1444                                 struct resource *parent, resource_size_t start,
1445                                 resource_size_t n, const char *name)
1446 {
1447         struct region_devres *dr = NULL;
1448         struct resource *res;
1449
1450         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1451                           GFP_KERNEL);
1452         if (!dr)
1453                 return NULL;
1454
1455         dr->parent = parent;
1456         dr->start = start;
1457         dr->n = n;
1458
1459         res = __request_region(parent, start, n, name, 0);
1460         if (res)
1461                 devres_add(dev, dr);
1462         else
1463                 devres_free(dr);
1464
1465         return res;
1466 }
1467 EXPORT_SYMBOL(__devm_request_region);
1468
1469 void __devm_release_region(struct device *dev, struct resource *parent,
1470                            resource_size_t start, resource_size_t n)
1471 {
1472         struct region_devres match_data = { parent, start, n };
1473
1474         __release_region(parent, start, n);
1475         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1476                                &match_data));
1477 }
1478 EXPORT_SYMBOL(__devm_release_region);
1479
1480 /*
1481  * Called from init/main.c to reserve IO ports.
1482  */
1483 #define MAXRESERVE 4
1484 static int __init reserve_setup(char *str)
1485 {
1486         static int reserved;
1487         static struct resource reserve[MAXRESERVE];
1488
1489         for (;;) {
1490                 unsigned int io_start, io_num;
1491                 int x = reserved;
1492
1493                 if (get_option (&str, &io_start) != 2)
1494                         break;
1495                 if (get_option (&str, &io_num)   == 0)
1496                         break;
1497                 if (x < MAXRESERVE) {
1498                         struct resource *res = reserve + x;
1499                         res->name = "reserved";
1500                         res->start = io_start;
1501                         res->end = io_start + io_num - 1;
1502                         res->flags = IORESOURCE_BUSY;
1503                         res->desc = IORES_DESC_NONE;
1504                         res->child = NULL;
1505                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1506                                 reserved = x+1;
1507                 }
1508         }
1509         return 1;
1510 }
1511
1512 __setup("reserve=", reserve_setup);
1513
1514 /*
1515  * Check if the requested addr and size spans more than any slot in the
1516  * iomem resource tree.
1517  */
1518 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1519 {
1520         struct resource *p = &iomem_resource;
1521         int err = 0;
1522         loff_t l;
1523
1524         read_lock(&resource_lock);
1525         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1526                 /*
1527                  * We can probably skip the resources without
1528                  * IORESOURCE_IO attribute?
1529                  */
1530                 if (p->start >= addr + size)
1531                         continue;
1532                 if (p->end < addr)
1533                         continue;
1534                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1535                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1536                         continue;
1537                 /*
1538                  * if a resource is "BUSY", it's not a hardware resource
1539                  * but a driver mapping of such a resource; we don't want
1540                  * to warn for those; some drivers legitimately map only
1541                  * partial hardware resources. (example: vesafb)
1542                  */
1543                 if (p->flags & IORESOURCE_BUSY)
1544                         continue;
1545
1546                 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1547                        (unsigned long long)addr,
1548                        (unsigned long long)(addr + size - 1),
1549                        p->name, p);
1550                 err = -1;
1551                 break;
1552         }
1553         read_unlock(&resource_lock);
1554
1555         return err;
1556 }
1557
1558 #ifdef CONFIG_STRICT_DEVMEM
1559 static int strict_iomem_checks = 1;
1560 #else
1561 static int strict_iomem_checks;
1562 #endif
1563
1564 /*
1565  * check if an address is reserved in the iomem resource tree
1566  * returns 1 if reserved, 0 if not reserved.
1567  */
1568 int iomem_is_exclusive(u64 addr)
1569 {
1570         struct resource *p = &iomem_resource;
1571         int err = 0;
1572         loff_t l;
1573         int size = PAGE_SIZE;
1574
1575         if (!strict_iomem_checks)
1576                 return 0;
1577
1578         addr = addr & PAGE_MASK;
1579
1580         read_lock(&resource_lock);
1581         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1582                 /*
1583                  * We can probably skip the resources without
1584                  * IORESOURCE_IO attribute?
1585                  */
1586                 if (p->start >= addr + size)
1587                         break;
1588                 if (p->end < addr)
1589                         continue;
1590                 /*
1591                  * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1592                  * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1593                  * resource is busy.
1594                  */
1595                 if ((p->flags & IORESOURCE_BUSY) == 0)
1596                         continue;
1597                 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1598                                 || p->flags & IORESOURCE_EXCLUSIVE) {
1599                         err = 1;
1600                         break;
1601                 }
1602         }
1603         read_unlock(&resource_lock);
1604
1605         return err;
1606 }
1607
1608 struct resource_entry *resource_list_create_entry(struct resource *res,
1609                                                   size_t extra_size)
1610 {
1611         struct resource_entry *entry;
1612
1613         entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1614         if (entry) {
1615                 INIT_LIST_HEAD(&entry->node);
1616                 entry->res = res ? res : &entry->__res;
1617         }
1618
1619         return entry;
1620 }
1621 EXPORT_SYMBOL(resource_list_create_entry);
1622
1623 void resource_list_free(struct list_head *head)
1624 {
1625         struct resource_entry *entry, *tmp;
1626
1627         list_for_each_entry_safe(entry, tmp, head, node)
1628                 resource_list_destroy_entry(entry);
1629 }
1630 EXPORT_SYMBOL(resource_list_free);
1631
1632 static int __init strict_iomem(char *str)
1633 {
1634         if (strstr(str, "relaxed"))
1635                 strict_iomem_checks = 0;
1636         if (strstr(str, "strict"))
1637                 strict_iomem_checks = 1;
1638         return 1;
1639 }
1640
1641 __setup("iomem=", strict_iomem);