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 #include <linux/module.h>
  11 #include <linux/errno.h>
  12 #include <linux/ioport.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/fs.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/seq_file.h>
  19 #include <linux/device.h>
  20 #include <linux/pfn.h>
  21 #include <asm/io.h>
  22
  23
  24 struct resource ioport_resource = {
  25         .name   = "PCI IO",
  26         .start  = 0,
  27         .end    = IO_SPACE_LIMIT,
  28         .flags  = IORESOURCE_IO,
  29 };
  30 EXPORT_SYMBOL(ioport_resource);
  31
  32 struct resource iomem_resource = {
  33         .name   = "PCI mem",
  34         .start  = 0,
  35         .end    = -1,
  36         .flags  = IORESOURCE_MEM,
  37 };
  38 EXPORT_SYMBOL(iomem_resource);
  39
  40 static DEFINE_RWLOCK(resource_lock);
  41
  42 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  43 {
  44         struct resource *p = v;
  45         (*pos)++;
  46         if (p->child)
  47                 return p->child;
  48         while (!p->sibling && p->parent)
  49                 p = p->parent;
  50         return p->sibling;
  51 }
  52
  53 #ifdef CONFIG_PROC_FS
  54
  55 enum { MAX_IORES_LEVEL = 5 };
  56
  57 static void *r_start(struct seq_file *m, loff_t *pos)
  58         __acquires(resource_lock)
  59 {
  60         struct resource *p = m->private;
  61         loff_t l = 0;
  62         read_lock(&resource_lock);
  63         for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  64                 ;
  65         return p;
  66 }
  67
  68 static void r_stop(struct seq_file *m, void *v)
  69         __releases(resource_lock)
  70 {
  71         read_unlock(&resource_lock);
  72 }
  73
  74 static int r_show(struct seq_file *m, void *v)
  75 {
  76         struct resource *root = m->private;
  77         struct resource *r = v, *p;
  78         int width = root->end < 0x10000 ? 4 : 8;
  79         int depth;
  80
  81         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
  82                 if (p->parent == root)
  83                         break;
  84         seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
  85                         depth * 2, "",
  86                         width, (unsigned long long) r->start,
  87                         width, (unsigned long long) r->end,
  88                         r->name ? r->name : "<BAD>");
  89         return 0;
  90 }
  91
  92 static const struct seq_operations resource_op = {
  93         .start  = r_start,
  94         .next   = r_next,
  95         .stop   = r_stop,
  96         .show   = r_show,
  97 };
  98
  99 static int ioports_open(struct inode *inode, struct file *file)
 100 {
 101         int res = seq_open(file, &resource_op);
 102         if (!res) {
 103                 struct seq_file *m = file->private_data;
 104                 m->private = &ioport_resource;
 105         }
 106         return res;
 107 }
 108
 109 static int iomem_open(struct inode *inode, struct file *file)
 110 {
 111         int res = seq_open(file, &resource_op);
 112         if (!res) {
 113                 struct seq_file *m = file->private_data;
 114                 m->private = &iomem_resource;
 115         }
 116         return res;
 117 }
 118
 119 static const struct file_operations proc_ioports_operations = {
 120         .open           = ioports_open,
 121         .read           = seq_read,
 122         .llseek         = seq_lseek,
 123         .release        = seq_release,
 124 };
 125
 126 static const struct file_operations proc_iomem_operations = {
 127         .open           = iomem_open,
 128         .read           = seq_read,
 129         .llseek         = seq_lseek,
 130         .release        = seq_release,
 131 };
 132
 133 static int __init ioresources_init(void)
 134 {
 135         proc_create("ioports", 0, NULL, &proc_ioports_operations);
 136         proc_create("iomem", 0, NULL, &proc_iomem_operations);
 137         return 0;
 138 }
 139 __initcall(ioresources_init);
 140
 141 #endif /* CONFIG_PROC_FS */
 142
 143 /* Return the conflict entry if you can't request it */
 144 static struct resource * __request_resource(struct resource *root, struct resource *new)
 145 {
 146         resource_size_t start = new->start;
 147         resource_size_t end = new->end;
 148         struct resource *tmp, **p;
 149
 150         if (end < start)
 151                 return root;
 152         if (start < root->start)
 153                 return root;
 154         if (end > root->end)
 155                 return root;
 156         p = &root->child;
 157         for (;;) {
 158                 tmp = *p;
 159                 if (!tmp || tmp->start > end) {
 160                         new->sibling = tmp;
 161                         *p = new;
 162                         new->parent = root;
 163                         return NULL;
 164                 }
 165                 p = &tmp->sibling;
 166                 if (tmp->end < start)
 167                         continue;
 168                 return tmp;
 169         }
 170 }
 171
 172 static int __release_resource(struct resource *old)
 173 {
 174         struct resource *tmp, **p;
 175
 176         if (old->child) {
 177                 static int warned;
 178                 if (warned < 5) {
 179                         warned++;
 180                         WARN_ON(1);
 181                 }
 182         }
 183
 184         WARN_ON(old->child);
 185
 186         p = &old->parent->child;
 187         for (;;) {
 188                 tmp = *p;
 189                 if (!tmp)
 190                         break;
 191                 if (tmp == old) {
 192                         *p = tmp->sibling;
 193                         old->parent = NULL;
 194                         return 0;
 195                 }
 196                 p = &tmp->sibling;
 197         }
 198         return -EINVAL;
 199 }
 200
 201 /**
 202  * request_resource - request and reserve an I/O or memory resource
 203  * @root: root resource descriptor
 204  * @new: resource descriptor desired by caller
 205  *
 206  * Returns 0 for success, negative error code on error.
 207  */
 208 int request_resource(struct resource *root, struct resource *new)
 209 {
 210         struct resource *conflict;
 211
 212         write_lock(&resource_lock);
 213         conflict = __request_resource(root, new);
 214         write_unlock(&resource_lock);
 215         return conflict ? -EBUSY : 0;
 216 }
 217
 218 EXPORT_SYMBOL(request_resource);
 219
 220 /**
 221  * release_resource - release a previously reserved resource
 222  * @old: resource pointer
 223  */
 224 int release_resource(struct resource *old)
 225 {
 226         int retval;
 227
 228         write_lock(&resource_lock);
 229         retval = __release_resource(old);
 230         write_unlock(&resource_lock);
 231         return retval;
 232 }
 233
 234 EXPORT_SYMBOL(release_resource);
 235
 236 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 237 /*
 238  * Finds the lowest memory reosurce exists within [res->start.res->end)
 239  * the caller must specify res->start, res->end, res->flags and "name".
 240  * If found, returns 0, res is overwritten, if not found, returns -1.
 241  */
 242 static int find_next_system_ram(struct resource *res, char *name)
 243 {
 244         resource_size_t start, end;
 245         struct resource *p;
 246
 247         BUG_ON(!res);
 248
 249         start = res->start;
 250         end = res->end;
 251         BUG_ON(start >= end);
 252
 253         read_lock(&resource_lock);
 254         for (p = iomem_resource.child; p ; p = p->sibling) {
 255                 /* system ram is just marked as IORESOURCE_MEM */
 256                 if (p->flags != res->flags)
 257                         continue;
 258                 if (name && strcmp(p->name, name))
 259                         continue;
 260                 if (p->start > end) {
 261                         p = NULL;
 262                         break;
 263                 }
 264                 if ((p->end >= start) && (p->start < end))
 265                         break;
 266         }
 267         read_unlock(&resource_lock);
 268         if (!p)
 269                 return -1;
 270         /* copy data */
 271         if (res->start < p->start)
 272                 res->start = p->start;
 273         if (res->end > p->end)
 274                 res->end = p->end;
 275         return 0;
 276 }
 277
 278 /*
 279  * This function calls callback against all memory range of "System RAM"
 280  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 281  * Now, this function is only for "System RAM".
 282  */
 283 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 284                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 285 {
 286         struct resource res;
 287         unsigned long pfn, len;
 288         u64 orig_end;
 289         int ret = -1;
 290
 291         res.start = (u64) start_pfn << PAGE_SHIFT;
 292         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 293         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 294         orig_end = res.end;
 295         while ((res.start < res.end) &&
 296                 (find_next_system_ram(&res, "System RAM") >= 0)) {
 297                 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
 298                 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
 299                 ret = (*func)(pfn, len, arg);
 300                 if (ret)
 301                         break;
 302                 res.start = res.end + 1;
 303                 res.end = orig_end;
 304         }
 305         return ret;
 306 }
 307
 308 #endif
 309
 310 /*
 311  * Find empty slot in the resource tree given range and alignment.
 312  */
 313 static int find_resource(struct resource *root, struct resource *new,
 314                          resource_size_t size, resource_size_t min,
 315                          resource_size_t max, resource_size_t align,
 316                          void (*alignf)(void *, struct resource *,
 317                                         resource_size_t, resource_size_t),
 318                          void *alignf_data)
 319 {
 320         struct resource *this = root->child;
 321
 322         new->start = root->start;
 323         /*
 324          * Skip past an allocated resource that starts at 0, since the assignment
 325          * of this->start - 1 to new->end below would cause an underflow.
 326          */
 327         if (this && this->start == 0) {
 328                 new->start = this->end + 1;
 329                 this = this->sibling;
 330         }
 331         for(;;) {
 332                 if (this)
 333                         new->end = this->start - 1;
 334                 else
 335                         new->end = root->end;
 336                 if (new->start < min)
 337                         new->start = min;
 338                 if (new->end > max)
 339                         new->end = max;
 340                 new->start = ALIGN(new->start, align);
 341                 if (alignf)
 342                         alignf(alignf_data, new, size, align);
 343                 if (new->start < new->end && new->end - new->start >= size - 1) {
 344                         new->end = new->start + size - 1;
 345                         return 0;
 346                 }
 347                 if (!this)
 348                         break;
 349                 new->start = this->end + 1;
 350                 this = this->sibling;
 351         }
 352         return -EBUSY;
 353 }
 354
 355 /**
 356  * allocate_resource - allocate empty slot in the resource tree given range & alignment
 357  * @root: root resource descriptor
 358  * @new: resource descriptor desired by caller
 359  * @size: requested resource region size
 360  * @min: minimum size to allocate
 361  * @max: maximum size to allocate
 362  * @align: alignment requested, in bytes
 363  * @alignf: alignment function, optional, called if not NULL
 364  * @alignf_data: arbitrary data to pass to the @alignf function
 365  */
 366 int allocate_resource(struct resource *root, struct resource *new,
 367                       resource_size_t size, resource_size_t min,
 368                       resource_size_t max, resource_size_t align,
 369                       void (*alignf)(void *, struct resource *,
 370                                      resource_size_t, resource_size_t),
 371                       void *alignf_data)
 372 {
 373         int err;
 374
 375         write_lock(&resource_lock);
 376         err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
 377         if (err >= 0 && __request_resource(root, new))
 378                 err = -EBUSY;
 379         write_unlock(&resource_lock);
 380         return err;
 381 }
 382
 383 EXPORT_SYMBOL(allocate_resource);
 384
 385 /*
 386  * Insert a resource into the resource tree. If successful, return NULL,
 387  * otherwise return the conflicting resource (compare to __request_resource())
 388  */
 389 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 390 {
 391         struct resource *first, *next;
 392
 393         for (;; parent = first) {
 394                 first = __request_resource(parent, new);
 395                 if (!first)
 396                         return first;
 397
 398                 if (first == parent)
 399                         return first;
 400
 401                 if ((first->start > new->start) || (first->end < new->end))
 402                         break;
 403                 if ((first->start == new->start) && (first->end == new->end))
 404                         break;
 405         }
 406
 407         for (next = first; ; next = next->sibling) {
 408                 /* Partial overlap? Bad, and unfixable */
 409                 if (next->start < new->start || next->end > new->end)
 410                         return next;
 411                 if (!next->sibling)
 412                         break;
 413                 if (next->sibling->start > new->end)
 414                         break;
 415         }
 416
 417         new->parent = parent;
 418         new->sibling = next->sibling;
 419         new->child = first;
 420
 421         next->sibling = NULL;
 422         for (next = first; next; next = next->sibling)
 423                 next->parent = new;
 424
 425         if (parent->child == first) {
 426                 parent->child = new;
 427         } else {
 428                 next = parent->child;
 429                 while (next->sibling != first)
 430                         next = next->sibling;
 431                 next->sibling = new;
 432         }
 433         return NULL;
 434 }
 435
 436 /**
 437  * insert_resource - Inserts a resource in the resource tree
 438  * @parent: parent of the new resource
 439  * @new: new resource to insert
 440  *
 441  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 442  *
 443  * This function is equivalent to request_resource when no conflict
 444  * happens. If a conflict happens, and the conflicting resources
 445  * entirely fit within the range of the new resource, then the new
 446  * resource is inserted and the conflicting resources become children of
 447  * the new resource.
 448  */
 449 int insert_resource(struct resource *parent, struct resource *new)
 450 {
 451         struct resource *conflict;
 452
 453         write_lock(&resource_lock);
 454         conflict = __insert_resource(parent, new);
 455         write_unlock(&resource_lock);
 456         return conflict ? -EBUSY : 0;
 457 }
 458
 459 /**
 460  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 461  * @root: root resource descriptor
 462  * @new: new resource to insert
 463  *
 464  * Insert a resource into the resource tree, possibly expanding it in order
 465  * to make it encompass any conflicting resources.
 466  */
 467 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 468 {
 469         if (new->parent)
 470                 return;
 471
 472         write_lock(&resource_lock);
 473         for (;;) {
 474                 struct resource *conflict;
 475
 476                 conflict = __insert_resource(root, new);
 477                 if (!conflict)
 478                         break;
 479                 if (conflict == root)
 480                         break;
 481
 482                 /* Ok, expand resource to cover the conflict, then try again .. */
 483                 if (conflict->start < new->start)
 484                         new->start = conflict->start;
 485                 if (conflict->end > new->end)
 486                         new->end = conflict->end;
 487
 488                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 489         }
 490         write_unlock(&resource_lock);
 491 }
 492
 493 /**
 494  * adjust_resource - modify a resource's start and size
 495  * @res: resource to modify
 496  * @start: new start value
 497  * @size: new size
 498  *
 499  * Given an existing resource, change its start and size to match the
 500  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 501  * Existing children of the resource are assumed to be immutable.
 502  */
 503 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
 504 {
 505         struct resource *tmp, *parent = res->parent;
 506         resource_size_t end = start + size - 1;
 507         int result = -EBUSY;
 508
 509         write_lock(&resource_lock);
 510
 511         if ((start < parent->start) || (end > parent->end))
 512                 goto out;
 513
 514         for (tmp = res->child; tmp; tmp = tmp->sibling) {
 515                 if ((tmp->start < start) || (tmp->end > end))
 516                         goto out;
 517         }
 518
 519         if (res->sibling && (res->sibling->start <= end))
 520                 goto out;
 521
 522         tmp = parent->child;
 523         if (tmp != res) {
 524                 while (tmp->sibling != res)
 525                         tmp = tmp->sibling;
 526                 if (start <= tmp->end)
 527                         goto out;
 528         }
 529
 530         res->start = start;
 531         res->end = end;
 532         result = 0;
 533
 534  out:
 535         write_unlock(&resource_lock);
 536         return result;
 537 }
 538
 539 static void __init __reserve_region_with_split(struct resource *root,
 540                 resource_size_t start, resource_size_t end,
 541                 const char *name)
 542 {
 543         struct resource *parent = root;
 544         struct resource *conflict;
 545         struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
 546
 547         if (!res)
 548                 return;
 549
 550         res->name = name;
 551         res->start = start;
 552         res->end = end;
 553         res->flags = IORESOURCE_BUSY;
 554
 555         conflict = __request_resource(parent, res);
 556         if (!conflict)
 557                 return;
 558
 559         /* failed, split and try again */
 560         kfree(res);
 561
 562         /* conflict covered whole area */
 563         if (conflict->start <= start && conflict->end >= end)
 564                 return;
 565
 566         if (conflict->start > start)
 567                 __reserve_region_with_split(root, start, conflict->start-1, name);
 568         if (conflict->end < end)
 569                 __reserve_region_with_split(root, conflict->end+1, end, name);
 570 }
 571
 572 void __init reserve_region_with_split(struct resource *root,
 573                 resource_size_t start, resource_size_t end,
 574                 const char *name)
 575 {
 576         write_lock(&resource_lock);
 577         __reserve_region_with_split(root, start, end, name);
 578         write_unlock(&resource_lock);
 579 }
 580
 581 EXPORT_SYMBOL(adjust_resource);
 582
 583 /**
 584  * resource_alignment - calculate resource's alignment
 585  * @res: resource pointer
 586  *
 587  * Returns alignment on success, 0 (invalid alignment) on failure.
 588  */
 589 resource_size_t resource_alignment(struct resource *res)
 590 {
 591         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 592         case IORESOURCE_SIZEALIGN:
 593                 return resource_size(res);
 594         case IORESOURCE_STARTALIGN:
 595                 return res->start;
 596         default:
 597                 return 0;
 598         }
 599 }
 600
 601 /*
 602  * This is compatibility stuff for IO resources.
 603  *
 604  * Note how this, unlike the above, knows about
 605  * the IO flag meanings (busy etc).
 606  *
 607  * request_region creates a new busy region.
 608  *
 609  * check_region returns non-zero if the area is already busy.
 610  *
 611  * release_region releases a matching busy region.
 612  */
 613
 614 /**
 615  * __request_region - create a new busy resource region
 616  * @parent: parent resource descriptor
 617  * @start: resource start address
 618  * @n: resource region size
 619  * @name: reserving caller's ID string
 620  * @flags: IO resource flags
 621  */
 622 struct resource * __request_region(struct resource *parent,
 623                                    resource_size_t start, resource_size_t n,
 624                                    const char *name, int flags)
 625 {
 626         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 627
 628         if (!res)
 629                 return NULL;
 630
 631         res->name = name;
 632         res->start = start;
 633         res->end = start + n - 1;
 634         res->flags = IORESOURCE_BUSY;
 635         res->flags |= flags;
 636
 637         write_lock(&resource_lock);
 638
 639         for (;;) {
 640                 struct resource *conflict;
 641
 642                 conflict = __request_resource(parent, res);
 643                 if (!conflict)
 644                         break;
 645                 if (conflict != parent) {
 646                         parent = conflict;
 647                         if (!(conflict->flags & IORESOURCE_BUSY))
 648                                 continue;
 649                 }
 650
 651                 /* Uhhuh, that didn't work out.. */
 652                 kfree(res);
 653                 res = NULL;
 654                 break;
 655         }
 656         write_unlock(&resource_lock);
 657         return res;
 658 }
 659 EXPORT_SYMBOL(__request_region);
 660
 661 /**
 662  * __check_region - check if a resource region is busy or free
 663  * @parent: parent resource descriptor
 664  * @start: resource start address
 665  * @n: resource region size
 666  *
 667  * Returns 0 if the region is free at the moment it is checked,
 668  * returns %-EBUSY if the region is busy.
 669  *
 670  * NOTE:
 671  * This function is deprecated because its use is racy.
 672  * Even if it returns 0, a subsequent call to request_region()
 673  * may fail because another driver etc. just allocated the region.
 674  * Do NOT use it.  It will be removed from the kernel.
 675  */
 676 int __check_region(struct resource *parent, resource_size_t start,
 677                         resource_size_t n)
 678 {
 679         struct resource * res;
 680
 681         res = __request_region(parent, start, n, "check-region", 0);
 682         if (!res)
 683                 return -EBUSY;
 684
 685         release_resource(res);
 686         kfree(res);
 687         return 0;
 688 }
 689 EXPORT_SYMBOL(__check_region);
 690
 691 /**
 692  * __release_region - release a previously reserved resource region
 693  * @parent: parent resource descriptor
 694  * @start: resource start address
 695  * @n: resource region size
 696  *
 697  * The described resource region must match a currently busy region.
 698  */
 699 void __release_region(struct resource *parent, resource_size_t start,
 700                         resource_size_t n)
 701 {
 702         struct resource **p;
 703         resource_size_t end;
 704
 705         p = &parent->child;
 706         end = start + n - 1;
 707
 708         write_lock(&resource_lock);
 709
 710         for (;;) {
 711                 struct resource *res = *p;
 712
 713                 if (!res)
 714                         break;
 715                 if (res->start <= start && res->end >= end) {
 716                         if (!(res->flags & IORESOURCE_BUSY)) {
 717                                 p = &res->child;
 718                                 continue;
 719                         }
 720                         if (res->start != start || res->end != end)
 721                                 break;
 722                         *p = res->sibling;
 723                         write_unlock(&resource_lock);
 724                         kfree(res);
 725                         return;
 726                 }
 727                 p = &res->sibling;
 728         }
 729
 730         write_unlock(&resource_lock);
 731
 732         printk(KERN_WARNING "Trying to free nonexistent resource "
 733                 "<%016llx-%016llx>\n", (unsigned long long)start,
 734                 (unsigned long long)end);
 735 }
 736 EXPORT_SYMBOL(__release_region);
 737
 738 /*
 739  * Managed region resource
 740  */
 741 struct region_devres {
 742         struct resource *parent;
 743         resource_size_t start;
 744         resource_size_t n;
 745 };
 746
 747 static void devm_region_release(struct device *dev, void *res)
 748 {
 749         struct region_devres *this = res;
 750
 751         __release_region(this->parent, this->start, this->n);
 752 }
 753
 754 static int devm_region_match(struct device *dev, void *res, void *match_data)
 755 {
 756         struct region_devres *this = res, *match = match_data;
 757
 758         return this->parent == match->parent &&
 759                 this->start == match->start && this->n == match->n;
 760 }
 761
 762 struct resource * __devm_request_region(struct device *dev,
 763                                 struct resource *parent, resource_size_t start,
 764                                 resource_size_t n, const char *name)
 765 {
 766         struct region_devres *dr = NULL;
 767         struct resource *res;
 768
 769         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
 770                           GFP_KERNEL);
 771         if (!dr)
 772                 return NULL;
 773
 774         dr->parent = parent;
 775         dr->start = start;
 776         dr->n = n;
 777
 778         res = __request_region(parent, start, n, name, 0);
 779         if (res)
 780                 devres_add(dev, dr);
 781         else
 782                 devres_free(dr);
 783
 784         return res;
 785 }
 786 EXPORT_SYMBOL(__devm_request_region);
 787
 788 void __devm_release_region(struct device *dev, struct resource *parent,
 789                            resource_size_t start, resource_size_t n)
 790 {
 791         struct region_devres match_data = { parent, start, n };
 792
 793         __release_region(parent, start, n);
 794         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
 795                                &match_data));
 796 }
 797 EXPORT_SYMBOL(__devm_release_region);
 798
 799 /*
 800  * Called from init/main.c to reserve IO ports.
 801  */
 802 #define MAXRESERVE 4
 803 static int __init reserve_setup(char *str)
 804 {
 805         static int reserved;
 806         static struct resource reserve[MAXRESERVE];
 807
 808         for (;;) {
 809                 unsigned int io_start, io_num;
 810                 int x = reserved;
 811
 812                 if (get_option (&str, &io_start) != 2)
 813                         break;
 814                 if (get_option (&str, &io_num)   == 0)
 815                         break;
 816                 if (x < MAXRESERVE) {
 817                         struct resource *res = reserve + x;
 818                         res->name = "reserved";
 819                         res->start = io_start;
 820                         res->end = io_start + io_num - 1;
 821                         res->flags = IORESOURCE_BUSY;
 822                         res->child = NULL;
 823                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
 824                                 reserved = x+1;
 825                 }
 826         }
 827         return 1;
 828 }
 829
 830 __setup("reserve=", reserve_setup);
 831
 832 /*
 833  * Check if the requested addr and size spans more than any slot in the
 834  * iomem resource tree.
 835  */
 836 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 837 {
 838         struct resource *p = &iomem_resource;
 839         int err = 0;
 840         loff_t l;
 841
 842         read_lock(&resource_lock);
 843         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 844                 /*
 845                  * We can probably skip the resources without
 846                  * IORESOURCE_IO attribute?
 847                  */
 848                 if (p->start >= addr + size)
 849                         continue;
 850                 if (p->end < addr)
 851                         continue;
 852                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
 853                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
 854                         continue;
 855                 /*
 856                  * if a resource is "BUSY", it's not a hardware resource
 857                  * but a driver mapping of such a resource; we don't want
 858                  * to warn for those; some drivers legitimately map only
 859                  * partial hardware resources. (example: vesafb)
 860                  */
 861                 if (p->flags & IORESOURCE_BUSY)
 862                         continue;
 863
 864                 printk(KERN_WARNING "resource map sanity check conflict: "
 865                        "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
 866                        (unsigned long long)addr,
 867                        (unsigned long long)(addr + size - 1),
 868                        (unsigned long long)p->start,
 869                        (unsigned long long)p->end,
 870                        p->name);
 871                 err = -1;
 872                 break;
 873         }
 874         read_unlock(&resource_lock);
 875
 876         return err;
 877 }
 878
 879 #ifdef CONFIG_STRICT_DEVMEM
 880 static int strict_iomem_checks = 1;
 881 #else
 882 static int strict_iomem_checks;
 883 #endif
 884
 885 /*
 886  * check if an address is reserved in the iomem resource tree
 887  * returns 1 if reserved, 0 if not reserved.
 888  */
 889 int iomem_is_exclusive(u64 addr)
 890 {
 891         struct resource *p = &iomem_resource;
 892         int err = 0;
 893         loff_t l;
 894         int size = PAGE_SIZE;
 895
 896         if (!strict_iomem_checks)
 897                 return 0;
 898
 899         addr = addr & PAGE_MASK;
 900
 901         read_lock(&resource_lock);
 902         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 903                 /*
 904                  * We can probably skip the resources without
 905                  * IORESOURCE_IO attribute?
 906                  */
 907                 if (p->start >= addr + size)
 908                         break;
 909                 if (p->end < addr)
 910                         continue;
 911                 if (p->flags & IORESOURCE_BUSY &&
 912                      p->flags & IORESOURCE_EXCLUSIVE) {
 913                         err = 1;
 914                         break;
 915                 }
 916         }
 917         read_unlock(&resource_lock);
 918
 919         return err;
 920 }
 921
 922 static int __init strict_iomem(char *str)
 923 {
 924         if (strstr(str, "relaxed"))
 925                 strict_iomem_checks = 0;
 926         if (strstr(str, "strict"))
 927                 strict_iomem_checks = 1;
 928         return 1;
 929 }
 930
 931 __setup("iomem=", strict_iomem);