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