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