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 static void __release_child_resources(struct resource *r)
 192 {
 193         struct resource *tmp, *p;
 194         resource_size_t size;
 195
 196         p = r->child;
 197         r->child = NULL;
 198         while (p) {
 199                 tmp = p;
 200                 p = p->sibling;
 201
 202                 tmp->parent = NULL;
 203                 tmp->sibling = NULL;
 204                 __release_child_resources(tmp);
 205
 206                 printk(KERN_DEBUG "release child resource %pR\n", tmp);
 207                 /* need to restore size, and keep flags */
 208                 size = resource_size(tmp);
 209                 tmp->start = 0;
 210                 tmp->end = size - 1;
 211         }
 212 }
 213
 214 void release_child_resources(struct resource *r)
 215 {
 216         write_lock(&resource_lock);
 217         __release_child_resources(r);
 218         write_unlock(&resource_lock);
 219 }
 220
 221 /**
 222  * request_resource - request and reserve an I/O or memory resource
 223  * @root: root resource descriptor
 224  * @new: resource descriptor desired by caller
 225  *
 226  * Returns 0 for success, negative error code on error.
 227  */
 228 int request_resource(struct resource *root, struct resource *new)
 229 {
 230         struct resource *conflict;
 231
 232         write_lock(&resource_lock);
 233         conflict = __request_resource(root, new);
 234         write_unlock(&resource_lock);
 235         return conflict ? -EBUSY : 0;
 236 }
 237
 238 EXPORT_SYMBOL(request_resource);
 239
 240 /**
 241  * release_resource - release a previously reserved resource
 242  * @old: resource pointer
 243  */
 244 int release_resource(struct resource *old)
 245 {
 246         int retval;
 247
 248         write_lock(&resource_lock);
 249         retval = __release_resource(old);
 250         write_unlock(&resource_lock);
 251         return retval;
 252 }
 253
 254 EXPORT_SYMBOL(release_resource);
 255
 256 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 257 /*
 258  * Finds the lowest memory reosurce exists within [res->start.res->end)
 259  * the caller must specify res->start, res->end, res->flags and "name".
 260  * If found, returns 0, res is overwritten, if not found, returns -1.
 261  */
 262 static int find_next_system_ram(struct resource *res, char *name)
 263 {
 264         resource_size_t start, end;
 265         struct resource *p;
 266
 267         BUG_ON(!res);
 268
 269         start = res->start;
 270         end = res->end;
 271         BUG_ON(start >= end);
 272
 273         read_lock(&resource_lock);
 274         for (p = iomem_resource.child; p ; p = p->sibling) {
 275                 /* system ram is just marked as IORESOURCE_MEM */
 276                 if (p->flags != res->flags)
 277                         continue;
 278                 if (name && strcmp(p->name, name))
 279                         continue;
 280                 if (p->start > end) {
 281                         p = NULL;
 282                         break;
 283                 }
 284                 if ((p->end >= start) && (p->start < end))
 285                         break;
 286         }
 287         read_unlock(&resource_lock);
 288         if (!p)
 289                 return -1;
 290         /* copy data */
 291         if (res->start < p->start)
 292                 res->start = p->start;
 293         if (res->end > p->end)
 294                 res->end = p->end;
 295         return 0;
 296 }
 297
 298 /*
 299  * This function calls callback against all memory range of "System RAM"
 300  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 301  * Now, this function is only for "System RAM".
 302  */
 303 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 304                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 305 {
 306         struct resource res;
 307         unsigned long pfn, end_pfn;
 308         u64 orig_end;
 309         int ret = -1;
 310
 311         res.start = (u64) start_pfn << PAGE_SHIFT;
 312         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 313         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 314         orig_end = res.end;
 315         while ((res.start < res.end) &&
 316                 (find_next_system_ram(&res, "System RAM") >= 0)) {
 317                 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 318                 end_pfn = (res.end + 1) >> PAGE_SHIFT;
 319                 if (end_pfn > pfn)
 320                         ret = (*func)(pfn, end_pfn - pfn, arg);
 321                 if (ret)
 322                         break;
 323                 res.start = res.end + 1;
 324                 res.end = orig_end;
 325         }
 326         return ret;
 327 }
 328
 329 #endif
 330
 331 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 332 {
 333         return 1;
 334 }
 335 /*
 336  * This generic page_is_ram() returns true if specified address is
 337  * registered as "System RAM" in iomem_resource list.
 338  */
 339 int __weak page_is_ram(unsigned long pfn)
 340 {
 341         return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 342 }
 343
 344 /*
 345  * Find empty slot in the resource tree given range and alignment.
 346  */
 347 static int find_resource(struct resource *root, struct resource *new,
 348                          resource_size_t size, resource_size_t min,
 349                          resource_size_t max, resource_size_t align,
 350                          resource_size_t (*alignf)(void *,
 351                                                    const struct resource *,
 352                                                    resource_size_t,
 353                                                    resource_size_t),
 354                          void *alignf_data)
 355 {
 356         struct resource *this = root->child;
 357         struct resource tmp = *new;
 358
 359         tmp.start = root->start;
 360         /*
 361          * Skip past an allocated resource that starts at 0, since the assignment
 362          * of this->start - 1 to tmp->end below would cause an underflow.
 363          */
 364         if (this && this->start == 0) {
 365                 tmp.start = this->end + 1;
 366                 this = this->sibling;
 367         }
 368         for(;;) {
 369                 if (this)
 370                         tmp.end = this->start - 1;
 371                 else
 372                         tmp.end = root->end;
 373                 if (tmp.start < min)
 374                         tmp.start = min;
 375                 if (tmp.end > max)
 376                         tmp.end = max;
 377                 tmp.start = ALIGN(tmp.start, align);
 378                 if (alignf)
 379                         tmp.start = alignf(alignf_data, &tmp, size, align);
 380                 if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
 381                         new->start = tmp.start;
 382                         new->end = tmp.start + size - 1;
 383                         return 0;
 384                 }
 385                 if (!this)
 386                         break;
 387                 tmp.start = this->end + 1;
 388                 this = this->sibling;
 389         }
 390         return -EBUSY;
 391 }
 392
 393 /**
 394  * allocate_resource - allocate empty slot in the resource tree given range & alignment
 395  * @root: root resource descriptor
 396  * @new: resource descriptor desired by caller
 397  * @size: requested resource region size
 398  * @min: minimum size to allocate
 399  * @max: maximum size to allocate
 400  * @align: alignment requested, in bytes
 401  * @alignf: alignment function, optional, called if not NULL
 402  * @alignf_data: arbitrary data to pass to the @alignf function
 403  */
 404 int allocate_resource(struct resource *root, struct resource *new,
 405                       resource_size_t size, resource_size_t min,
 406                       resource_size_t max, resource_size_t align,
 407                       resource_size_t (*alignf)(void *,
 408                                                 const struct resource *,
 409                                                 resource_size_t,
 410                                                 resource_size_t),
 411                       void *alignf_data)
 412 {
 413         int err;
 414
 415         write_lock(&resource_lock);
 416         err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
 417         if (err >= 0 && __request_resource(root, new))
 418                 err = -EBUSY;
 419         write_unlock(&resource_lock);
 420         return err;
 421 }
 422
 423 EXPORT_SYMBOL(allocate_resource);
 424
 425 /*
 426  * Insert a resource into the resource tree. If successful, return NULL,
 427  * otherwise return the conflicting resource (compare to __request_resource())
 428  */
 429 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 430 {
 431         struct resource *first, *next;
 432
 433         for (;; parent = first) {
 434                 first = __request_resource(parent, new);
 435                 if (!first)
 436                         return first;
 437
 438                 if (first == parent)
 439                         return first;
 440
 441                 if ((first->start > new->start) || (first->end < new->end))
 442                         break;
 443                 if ((first->start == new->start) && (first->end == new->end))
 444                         break;
 445         }
 446
 447         for (next = first; ; next = next->sibling) {
 448                 /* Partial overlap? Bad, and unfixable */
 449                 if (next->start < new->start || next->end > new->end)
 450                         return next;
 451                 if (!next->sibling)
 452                         break;
 453                 if (next->sibling->start > new->end)
 454                         break;
 455         }
 456
 457         new->parent = parent;
 458         new->sibling = next->sibling;
 459         new->child = first;
 460
 461         next->sibling = NULL;
 462         for (next = first; next; next = next->sibling)
 463                 next->parent = new;
 464
 465         if (parent->child == first) {
 466                 parent->child = new;
 467         } else {
 468                 next = parent->child;
 469                 while (next->sibling != first)
 470                         next = next->sibling;
 471                 next->sibling = new;
 472         }
 473         return NULL;
 474 }
 475
 476 /**
 477  * insert_resource - Inserts a resource in the resource tree
 478  * @parent: parent of the new resource
 479  * @new: new resource to insert
 480  *
 481  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 482  *
 483  * This function is equivalent to request_resource when no conflict
 484  * happens. If a conflict happens, and the conflicting resources
 485  * entirely fit within the range of the new resource, then the new
 486  * resource is inserted and the conflicting resources become children of
 487  * the new resource.
 488  */
 489 int insert_resource(struct resource *parent, struct resource *new)
 490 {
 491         struct resource *conflict;
 492
 493         write_lock(&resource_lock);
 494         conflict = __insert_resource(parent, new);
 495         write_unlock(&resource_lock);
 496         return conflict ? -EBUSY : 0;
 497 }
 498
 499 /**
 500  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 501  * @root: root resource descriptor
 502  * @new: new resource to insert
 503  *
 504  * Insert a resource into the resource tree, possibly expanding it in order
 505  * to make it encompass any conflicting resources.
 506  */
 507 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 508 {
 509         if (new->parent)
 510                 return;
 511
 512         write_lock(&resource_lock);
 513         for (;;) {
 514                 struct resource *conflict;
 515
 516                 conflict = __insert_resource(root, new);
 517                 if (!conflict)
 518                         break;
 519                 if (conflict == root)
 520                         break;
 521
 522                 /* Ok, expand resource to cover the conflict, then try again .. */
 523                 if (conflict->start < new->start)
 524                         new->start = conflict->start;
 525                 if (conflict->end > new->end)
 526                         new->end = conflict->end;
 527
 528                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 529         }
 530         write_unlock(&resource_lock);
 531 }
 532
 533 /**
 534  * adjust_resource - modify a resource's start and size
 535  * @res: resource to modify
 536  * @start: new start value
 537  * @size: new size
 538  *
 539  * Given an existing resource, change its start and size to match the
 540  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 541  * Existing children of the resource are assumed to be immutable.
 542  */
 543 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
 544 {
 545         struct resource *tmp, *parent = res->parent;
 546         resource_size_t end = start + size - 1;
 547         int result = -EBUSY;
 548
 549         write_lock(&resource_lock);
 550
 551         if ((start < parent->start) || (end > parent->end))
 552                 goto out;
 553
 554         for (tmp = res->child; tmp; tmp = tmp->sibling) {
 555                 if ((tmp->start < start) || (tmp->end > end))
 556                         goto out;
 557         }
 558
 559         if (res->sibling && (res->sibling->start <= end))
 560                 goto out;
 561
 562         tmp = parent->child;
 563         if (tmp != res) {
 564                 while (tmp->sibling != res)
 565                         tmp = tmp->sibling;
 566                 if (start <= tmp->end)
 567                         goto out;
 568         }
 569
 570         res->start = start;
 571         res->end = end;
 572         result = 0;
 573
 574  out:
 575         write_unlock(&resource_lock);
 576         return result;
 577 }
 578
 579 static void __init __reserve_region_with_split(struct resource *root,
 580                 resource_size_t start, resource_size_t end,
 581                 const char *name)
 582 {
 583         struct resource *parent = root;
 584         struct resource *conflict;
 585         struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
 586
 587         if (!res)
 588                 return;
 589
 590         res->name = name;
 591         res->start = start;
 592         res->end = end;
 593         res->flags = IORESOURCE_BUSY;
 594
 595         conflict = __request_resource(parent, res);
 596         if (!conflict)
 597                 return;
 598
 599         /* failed, split and try again */
 600         kfree(res);
 601
 602         /* conflict covered whole area */
 603         if (conflict->start <= start && conflict->end >= end)
 604                 return;
 605
 606         if (conflict->start > start)
 607                 __reserve_region_with_split(root, start, conflict->start-1, name);
 608         if (conflict->end < end)
 609                 __reserve_region_with_split(root, conflict->end+1, end, name);
 610 }
 611
 612 void __init reserve_region_with_split(struct resource *root,
 613                 resource_size_t start, resource_size_t end,
 614                 const char *name)
 615 {
 616         write_lock(&resource_lock);
 617         __reserve_region_with_split(root, start, end, name);
 618         write_unlock(&resource_lock);
 619 }
 620
 621 EXPORT_SYMBOL(adjust_resource);
 622
 623 /**
 624  * resource_alignment - calculate resource's alignment
 625  * @res: resource pointer
 626  *
 627  * Returns alignment on success, 0 (invalid alignment) on failure.
 628  */
 629 resource_size_t resource_alignment(struct resource *res)
 630 {
 631         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 632         case IORESOURCE_SIZEALIGN:
 633                 return resource_size(res);
 634         case IORESOURCE_STARTALIGN:
 635                 return res->start;
 636         default:
 637                 return 0;
 638         }
 639 }
 640
 641 /*
 642  * This is compatibility stuff for IO resources.
 643  *
 644  * Note how this, unlike the above, knows about
 645  * the IO flag meanings (busy etc).
 646  *
 647  * request_region creates a new busy region.
 648  *
 649  * check_region returns non-zero if the area is already busy.
 650  *
 651  * release_region releases a matching busy region.
 652  */
 653
 654 /**
 655  * __request_region - create a new busy resource region
 656  * @parent: parent resource descriptor
 657  * @start: resource start address
 658  * @n: resource region size
 659  * @name: reserving caller's ID string
 660  * @flags: IO resource flags
 661  */
 662 struct resource * __request_region(struct resource *parent,
 663                                    resource_size_t start, resource_size_t n,
 664                                    const char *name, int flags)
 665 {
 666         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 667
 668         if (!res)
 669                 return NULL;
 670
 671         res->name = name;
 672         res->start = start;
 673         res->end = start + n - 1;
 674         res->flags = IORESOURCE_BUSY;
 675         res->flags |= flags;
 676
 677         write_lock(&resource_lock);
 678
 679         for (;;) {
 680                 struct resource *conflict;
 681
 682                 conflict = __request_resource(parent, res);
 683                 if (!conflict)
 684                         break;
 685                 if (conflict != parent) {
 686                         parent = conflict;
 687                         if (!(conflict->flags & IORESOURCE_BUSY))
 688                                 continue;
 689                 }
 690
 691                 /* Uhhuh, that didn't work out.. */
 692                 kfree(res);
 693                 res = NULL;
 694                 break;
 695         }
 696         write_unlock(&resource_lock);
 697         return res;
 698 }
 699 EXPORT_SYMBOL(__request_region);
 700
 701 /**
 702  * __check_region - check if a resource region is busy or free
 703  * @parent: parent resource descriptor
 704  * @start: resource start address
 705  * @n: resource region size
 706  *
 707  * Returns 0 if the region is free at the moment it is checked,
 708  * returns %-EBUSY if the region is busy.
 709  *
 710  * NOTE:
 711  * This function is deprecated because its use is racy.
 712  * Even if it returns 0, a subsequent call to request_region()
 713  * may fail because another driver etc. just allocated the region.
 714  * Do NOT use it.  It will be removed from the kernel.
 715  */
 716 int __check_region(struct resource *parent, resource_size_t start,
 717                         resource_size_t n)
 718 {
 719         struct resource * res;
 720
 721         res = __request_region(parent, start, n, "check-region", 0);
 722         if (!res)
 723                 return -EBUSY;
 724
 725         release_resource(res);
 726         kfree(res);
 727         return 0;
 728 }
 729 EXPORT_SYMBOL(__check_region);
 730
 731 /**
 732  * __release_region - release a previously reserved resource region
 733  * @parent: parent resource descriptor
 734  * @start: resource start address
 735  * @n: resource region size
 736  *
 737  * The described resource region must match a currently busy region.
 738  */
 739 void __release_region(struct resource *parent, resource_size_t start,
 740                         resource_size_t n)
 741 {
 742         struct resource **p;
 743         resource_size_t end;
 744
 745         p = &parent->child;
 746         end = start + n - 1;
 747
 748         write_lock(&resource_lock);
 749
 750         for (;;) {
 751                 struct resource *res = *p;
 752
 753                 if (!res)
 754                         break;
 755                 if (res->start <= start && res->end >= end) {
 756                         if (!(res->flags & IORESOURCE_BUSY)) {
 757                                 p = &res->child;
 758                                 continue;
 759                         }
 760                         if (res->start != start || res->end != end)
 761                                 break;
 762                         *p = res->sibling;
 763                         write_unlock(&resource_lock);
 764                         kfree(res);
 765                         return;
 766                 }
 767                 p = &res->sibling;
 768         }
 769
 770         write_unlock(&resource_lock);
 771
 772         printk(KERN_WARNING "Trying to free nonexistent resource "
 773                 "<%016llx-%016llx>\n", (unsigned long long)start,
 774                 (unsigned long long)end);
 775 }
 776 EXPORT_SYMBOL(__release_region);
 777
 778 /*
 779  * Managed region resource
 780  */
 781 struct region_devres {
 782         struct resource *parent;
 783         resource_size_t start;
 784         resource_size_t n;
 785 };
 786
 787 static void devm_region_release(struct device *dev, void *res)
 788 {
 789         struct region_devres *this = res;
 790
 791         __release_region(this->parent, this->start, this->n);
 792 }
 793
 794 static int devm_region_match(struct device *dev, void *res, void *match_data)
 795 {
 796         struct region_devres *this = res, *match = match_data;
 797
 798         return this->parent == match->parent &&
 799                 this->start == match->start && this->n == match->n;
 800 }
 801
 802 struct resource * __devm_request_region(struct device *dev,
 803                                 struct resource *parent, resource_size_t start,
 804                                 resource_size_t n, const char *name)
 805 {
 806         struct region_devres *dr = NULL;
 807         struct resource *res;
 808
 809         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
 810                           GFP_KERNEL);
 811         if (!dr)
 812                 return NULL;
 813
 814         dr->parent = parent;
 815         dr->start = start;
 816         dr->n = n;
 817
 818         res = __request_region(parent, start, n, name, 0);
 819         if (res)
 820                 devres_add(dev, dr);
 821         else
 822                 devres_free(dr);
 823
 824         return res;
 825 }
 826 EXPORT_SYMBOL(__devm_request_region);
 827
 828 void __devm_release_region(struct device *dev, struct resource *parent,
 829                            resource_size_t start, resource_size_t n)
 830 {
 831         struct region_devres match_data = { parent, start, n };
 832
 833         __release_region(parent, start, n);
 834         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
 835                                &match_data));
 836 }
 837 EXPORT_SYMBOL(__devm_release_region);
 838
 839 /*
 840  * Called from init/main.c to reserve IO ports.
 841  */
 842 #define MAXRESERVE 4
 843 static int __init reserve_setup(char *str)
 844 {
 845         static int reserved;
 846         static struct resource reserve[MAXRESERVE];
 847
 848         for (;;) {
 849                 unsigned int io_start, io_num;
 850                 int x = reserved;
 851
 852                 if (get_option (&str, &io_start) != 2)
 853                         break;
 854                 if (get_option (&str, &io_num)   == 0)
 855                         break;
 856                 if (x < MAXRESERVE) {
 857                         struct resource *res = reserve + x;
 858                         res->name = "reserved";
 859                         res->start = io_start;
 860                         res->end = io_start + io_num - 1;
 861                         res->flags = IORESOURCE_BUSY;
 862                         res->child = NULL;
 863                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
 864                                 reserved = x+1;
 865                 }
 866         }
 867         return 1;
 868 }
 869
 870 __setup("reserve=", reserve_setup);
 871
 872 /*
 873  * Check if the requested addr and size spans more than any slot in the
 874  * iomem resource tree.
 875  */
 876 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 877 {
 878         struct resource *p = &iomem_resource;
 879         int err = 0;
 880         loff_t l;
 881
 882         read_lock(&resource_lock);
 883         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 884                 /*
 885                  * We can probably skip the resources without
 886                  * IORESOURCE_IO attribute?
 887                  */
 888                 if (p->start >= addr + size)
 889                         continue;
 890                 if (p->end < addr)
 891                         continue;
 892                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
 893                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
 894                         continue;
 895                 /*
 896                  * if a resource is "BUSY", it's not a hardware resource
 897                  * but a driver mapping of such a resource; we don't want
 898                  * to warn for those; some drivers legitimately map only
 899                  * partial hardware resources. (example: vesafb)
 900                  */
 901                 if (p->flags & IORESOURCE_BUSY)
 902                         continue;
 903
 904                 printk(KERN_WARNING "resource map sanity check conflict: "
 905                        "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
 906                        (unsigned long long)addr,
 907                        (unsigned long long)(addr + size - 1),
 908                        (unsigned long long)p->start,
 909                        (unsigned long long)p->end,
 910                        p->name);
 911                 err = -1;
 912                 break;
 913         }
 914         read_unlock(&resource_lock);
 915
 916         return err;
 917 }
 918
 919 #ifdef CONFIG_STRICT_DEVMEM
 920 static int strict_iomem_checks = 1;
 921 #else
 922 static int strict_iomem_checks;
 923 #endif
 924
 925 /*
 926  * check if an address is reserved in the iomem resource tree
 927  * returns 1 if reserved, 0 if not reserved.
 928  */
 929 int iomem_is_exclusive(u64 addr)
 930 {
 931         struct resource *p = &iomem_resource;
 932         int err = 0;
 933         loff_t l;
 934         int size = PAGE_SIZE;
 935
 936         if (!strict_iomem_checks)
 937                 return 0;
 938
 939         addr = addr & PAGE_MASK;
 940
 941         read_lock(&resource_lock);
 942         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 943                 /*
 944                  * We can probably skip the resources without
 945                  * IORESOURCE_IO attribute?
 946                  */
 947                 if (p->start >= addr + size)
 948                         break;
 949                 if (p->end < addr)
 950                         continue;
 951                 if (p->flags & IORESOURCE_BUSY &&
 952                      p->flags & IORESOURCE_EXCLUSIVE) {
 953                         err = 1;
 954                         break;
 955                 }
 956         }
 957         read_unlock(&resource_lock);
 958
 959         return err;
 960 }
 961
 962 static int __init strict_iomem(char *str)
 963 {
 964         if (strstr(str, "relaxed"))
 965                 strict_iomem_checks = 0;
 966         if (strstr(str, "strict"))
 967                 strict_iomem_checks = 1;
 968         return 1;
 969 }
 970
 971 __setup("iomem=", strict_iomem);