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_conflict - 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, conflict resource on error.
 227  */
 228 struct resource *request_resource_conflict(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;
 236 }
 237
 238 /**
 239  * request_resource - request and reserve an I/O or memory resource
 240  * @root: root resource descriptor
 241  * @new: resource descriptor desired by caller
 242  *
 243  * Returns 0 for success, negative error code on error.
 244  */
 245 int request_resource(struct resource *root, struct resource *new)
 246 {
 247         struct resource *conflict;
 248
 249         conflict = request_resource_conflict(root, new);
 250         return conflict ? -EBUSY : 0;
 251 }
 252
 253 EXPORT_SYMBOL(request_resource);
 254
 255 /**
 256  * release_resource - release a previously reserved resource
 257  * @old: resource pointer
 258  */
 259 int release_resource(struct resource *old)
 260 {
 261         int retval;
 262
 263         write_lock(&resource_lock);
 264         retval = __release_resource(old);
 265         write_unlock(&resource_lock);
 266         return retval;
 267 }
 268
 269 EXPORT_SYMBOL(release_resource);
 270
 271 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 272 /*
 273  * Finds the lowest memory reosurce exists within [res->start.res->end)
 274  * the caller must specify res->start, res->end, res->flags and "name".
 275  * If found, returns 0, res is overwritten, if not found, returns -1.
 276  */
 277 static int find_next_system_ram(struct resource *res, char *name)
 278 {
 279         resource_size_t start, end;
 280         struct resource *p;
 281
 282         BUG_ON(!res);
 283
 284         start = res->start;
 285         end = res->end;
 286         BUG_ON(start >= end);
 287
 288         read_lock(&resource_lock);
 289         for (p = iomem_resource.child; p ; p = p->sibling) {
 290                 /* system ram is just marked as IORESOURCE_MEM */
 291                 if (p->flags != res->flags)
 292                         continue;
 293                 if (name && strcmp(p->name, name))
 294                         continue;
 295                 if (p->start > end) {
 296                         p = NULL;
 297                         break;
 298                 }
 299                 if ((p->end >= start) && (p->start < end))
 300                         break;
 301         }
 302         read_unlock(&resource_lock);
 303         if (!p)
 304                 return -1;
 305         /* copy data */
 306         if (res->start < p->start)
 307                 res->start = p->start;
 308         if (res->end > p->end)
 309                 res->end = p->end;
 310         return 0;
 311 }
 312
 313 /*
 314  * This function calls callback against all memory range of "System RAM"
 315  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 316  * Now, this function is only for "System RAM".
 317  */
 318 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 319                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 320 {
 321         struct resource res;
 322         unsigned long pfn, end_pfn;
 323         u64 orig_end;
 324         int ret = -1;
 325
 326         res.start = (u64) start_pfn << PAGE_SHIFT;
 327         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 328         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 329         orig_end = res.end;
 330         while ((res.start < res.end) &&
 331                 (find_next_system_ram(&res, "System RAM") >= 0)) {
 332                 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 333                 end_pfn = (res.end + 1) >> PAGE_SHIFT;
 334                 if (end_pfn > pfn)
 335                         ret = (*func)(pfn, end_pfn - pfn, arg);
 336                 if (ret)
 337                         break;
 338                 res.start = res.end + 1;
 339                 res.end = orig_end;
 340         }
 341         return ret;
 342 }
 343
 344 #endif
 345
 346 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 347 {
 348         return 1;
 349 }
 350 /*
 351  * This generic page_is_ram() returns true if specified address is
 352  * registered as "System RAM" in iomem_resource list.
 353  */
 354 int __weak page_is_ram(unsigned long pfn)
 355 {
 356         return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 357 }
 358
 359 /*
 360  * Find empty slot in the resource tree given range and alignment.
 361  */
 362 static int find_resource(struct resource *root, struct resource *new,
 363                          resource_size_t size, resource_size_t min,
 364                          resource_size_t max, resource_size_t align,
 365                          resource_size_t (*alignf)(void *,
 366                                                    const struct resource *,
 367                                                    resource_size_t,
 368                                                    resource_size_t),
 369                          void *alignf_data)
 370 {
 371         struct resource *this = root->child;
 372         struct resource tmp = *new;
 373
 374         tmp.start = root->start;
 375         /*
 376          * Skip past an allocated resource that starts at 0, since the assignment
 377          * of this->start - 1 to tmp->end below would cause an underflow.
 378          */
 379         if (this && this->start == 0) {
 380                 tmp.start = this->end + 1;
 381                 this = this->sibling;
 382         }
 383         for(;;) {
 384                 if (this)
 385                         tmp.end = this->start - 1;
 386                 else
 387                         tmp.end = root->end;
 388                 if (tmp.start < min)
 389                         tmp.start = min;
 390                 if (tmp.end > max)
 391                         tmp.end = max;
 392                 tmp.start = ALIGN(tmp.start, align);
 393                 if (alignf)
 394                         tmp.start = alignf(alignf_data, &tmp, size, align);
 395                 if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
 396                         new->start = tmp.start;
 397                         new->end = tmp.start + size - 1;
 398                         return 0;
 399                 }
 400                 if (!this)
 401                         break;
 402                 tmp.start = this->end + 1;
 403                 this = this->sibling;
 404         }
 405         return -EBUSY;
 406 }
 407
 408 /**
 409  * allocate_resource - allocate empty slot in the resource tree given range & alignment
 410  * @root: root resource descriptor
 411  * @new: resource descriptor desired by caller
 412  * @size: requested resource region size
 413  * @min: minimum size to allocate
 414  * @max: maximum size to allocate
 415  * @align: alignment requested, in bytes
 416  * @alignf: alignment function, optional, called if not NULL
 417  * @alignf_data: arbitrary data to pass to the @alignf function
 418  */
 419 int allocate_resource(struct resource *root, struct resource *new,
 420                       resource_size_t size, resource_size_t min,
 421                       resource_size_t max, resource_size_t align,
 422                       resource_size_t (*alignf)(void *,
 423                                                 const struct resource *,
 424                                                 resource_size_t,
 425                                                 resource_size_t),
 426                       void *alignf_data)
 427 {
 428         int err;
 429
 430         write_lock(&resource_lock);
 431         err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
 432         if (err >= 0 && __request_resource(root, new))
 433                 err = -EBUSY;
 434         write_unlock(&resource_lock);
 435         return err;
 436 }
 437
 438 EXPORT_SYMBOL(allocate_resource);
 439
 440 /*
 441  * Insert a resource into the resource tree. If successful, return NULL,
 442  * otherwise return the conflicting resource (compare to __request_resource())
 443  */
 444 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 445 {
 446         struct resource *first, *next;
 447
 448         for (;; parent = first) {
 449                 first = __request_resource(parent, new);
 450                 if (!first)
 451                         return first;
 452
 453                 if (first == parent)
 454                         return first;
 455
 456                 if ((first->start > new->start) || (first->end < new->end))
 457                         break;
 458                 if ((first->start == new->start) && (first->end == new->end))
 459                         break;
 460         }
 461
 462         for (next = first; ; next = next->sibling) {
 463                 /* Partial overlap? Bad, and unfixable */
 464                 if (next->start < new->start || next->end > new->end)
 465                         return next;
 466                 if (!next->sibling)
 467                         break;
 468                 if (next->sibling->start > new->end)
 469                         break;
 470         }
 471
 472         new->parent = parent;
 473         new->sibling = next->sibling;
 474         new->child = first;
 475
 476         next->sibling = NULL;
 477         for (next = first; next; next = next->sibling)
 478                 next->parent = new;
 479
 480         if (parent->child == first) {
 481                 parent->child = new;
 482         } else {
 483                 next = parent->child;
 484                 while (next->sibling != first)
 485                         next = next->sibling;
 486                 next->sibling = new;
 487         }
 488         return NULL;
 489 }
 490
 491 /**
 492  * insert_resource_conflict - Inserts resource in the resource tree
 493  * @parent: parent of the new resource
 494  * @new: new resource to insert
 495  *
 496  * Returns 0 on success, conflict resource if the resource can't be inserted.
 497  *
 498  * This function is equivalent to request_resource_conflict when no conflict
 499  * happens. If a conflict happens, and the conflicting resources
 500  * entirely fit within the range of the new resource, then the new
 501  * resource is inserted and the conflicting resources become children of
 502  * the new resource.
 503  */
 504 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 505 {
 506         struct resource *conflict;
 507
 508         write_lock(&resource_lock);
 509         conflict = __insert_resource(parent, new);
 510         write_unlock(&resource_lock);
 511         return conflict;
 512 }
 513
 514 /**
 515  * insert_resource - Inserts a resource in the resource tree
 516  * @parent: parent of the new resource
 517  * @new: new resource to insert
 518  *
 519  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 520  */
 521 int insert_resource(struct resource *parent, struct resource *new)
 522 {
 523         struct resource *conflict;
 524
 525         conflict = insert_resource_conflict(parent, new);
 526         return conflict ? -EBUSY : 0;
 527 }
 528
 529 /**
 530  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 531  * @root: root resource descriptor
 532  * @new: new resource to insert
 533  *
 534  * Insert a resource into the resource tree, possibly expanding it in order
 535  * to make it encompass any conflicting resources.
 536  */
 537 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 538 {
 539         if (new->parent)
 540                 return;
 541
 542         write_lock(&resource_lock);
 543         for (;;) {
 544                 struct resource *conflict;
 545
 546                 conflict = __insert_resource(root, new);
 547                 if (!conflict)
 548                         break;
 549                 if (conflict == root)
 550                         break;
 551
 552                 /* Ok, expand resource to cover the conflict, then try again .. */
 553                 if (conflict->start < new->start)
 554                         new->start = conflict->start;
 555                 if (conflict->end > new->end)
 556                         new->end = conflict->end;
 557
 558                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 559         }
 560         write_unlock(&resource_lock);
 561 }
 562
 563 /**
 564  * adjust_resource - modify a resource's start and size
 565  * @res: resource to modify
 566  * @start: new start value
 567  * @size: new size
 568  *
 569  * Given an existing resource, change its start and size to match the
 570  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 571  * Existing children of the resource are assumed to be immutable.
 572  */
 573 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
 574 {
 575         struct resource *tmp, *parent = res->parent;
 576         resource_size_t end = start + size - 1;
 577         int result = -EBUSY;
 578
 579         write_lock(&resource_lock);
 580
 581         if ((start < parent->start) || (end > parent->end))
 582                 goto out;
 583
 584         for (tmp = res->child; tmp; tmp = tmp->sibling) {
 585                 if ((tmp->start < start) || (tmp->end > end))
 586                         goto out;
 587         }
 588
 589         if (res->sibling && (res->sibling->start <= end))
 590                 goto out;
 591
 592         tmp = parent->child;
 593         if (tmp != res) {
 594                 while (tmp->sibling != res)
 595                         tmp = tmp->sibling;
 596                 if (start <= tmp->end)
 597                         goto out;
 598         }
 599
 600         res->start = start;
 601         res->end = end;
 602         result = 0;
 603
 604  out:
 605         write_unlock(&resource_lock);
 606         return result;
 607 }
 608
 609 static void __init __reserve_region_with_split(struct resource *root,
 610                 resource_size_t start, resource_size_t end,
 611                 const char *name)
 612 {
 613         struct resource *parent = root;
 614         struct resource *conflict;
 615         struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
 616
 617         if (!res)
 618                 return;
 619
 620         res->name = name;
 621         res->start = start;
 622         res->end = end;
 623         res->flags = IORESOURCE_BUSY;
 624
 625         conflict = __request_resource(parent, res);
 626         if (!conflict)
 627                 return;
 628
 629         /* failed, split and try again */
 630         kfree(res);
 631
 632         /* conflict covered whole area */
 633         if (conflict->start <= start && conflict->end >= end)
 634                 return;
 635
 636         if (conflict->start > start)
 637                 __reserve_region_with_split(root, start, conflict->start-1, name);
 638         if (conflict->end < end)
 639                 __reserve_region_with_split(root, conflict->end+1, end, name);
 640 }
 641
 642 void __init reserve_region_with_split(struct resource *root,
 643                 resource_size_t start, resource_size_t end,
 644                 const char *name)
 645 {
 646         write_lock(&resource_lock);
 647         __reserve_region_with_split(root, start, end, name);
 648         write_unlock(&resource_lock);
 649 }
 650
 651 EXPORT_SYMBOL(adjust_resource);
 652
 653 /**
 654  * resource_alignment - calculate resource's alignment
 655  * @res: resource pointer
 656  *
 657  * Returns alignment on success, 0 (invalid alignment) on failure.
 658  */
 659 resource_size_t resource_alignment(struct resource *res)
 660 {
 661         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 662         case IORESOURCE_SIZEALIGN:
 663                 return resource_size(res);
 664         case IORESOURCE_STARTALIGN:
 665                 return res->start;
 666         default:
 667                 return 0;
 668         }
 669 }
 670
 671 /*
 672  * This is compatibility stuff for IO resources.
 673  *
 674  * Note how this, unlike the above, knows about
 675  * the IO flag meanings (busy etc).
 676  *
 677  * request_region creates a new busy region.
 678  *
 679  * check_region returns non-zero if the area is already busy.
 680  *
 681  * release_region releases a matching busy region.
 682  */
 683
 684 /**
 685  * __request_region - create a new busy resource region
 686  * @parent: parent resource descriptor
 687  * @start: resource start address
 688  * @n: resource region size
 689  * @name: reserving caller's ID string
 690  * @flags: IO resource flags
 691  */
 692 struct resource * __request_region(struct resource *parent,
 693                                    resource_size_t start, resource_size_t n,
 694                                    const char *name, int flags)
 695 {
 696         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 697
 698         if (!res)
 699                 return NULL;
 700
 701         res->name = name;
 702         res->start = start;
 703         res->end = start + n - 1;
 704         res->flags = IORESOURCE_BUSY;
 705         res->flags |= flags;
 706
 707         write_lock(&resource_lock);
 708
 709         for (;;) {
 710                 struct resource *conflict;
 711
 712                 conflict = __request_resource(parent, res);
 713                 if (!conflict)
 714                         break;
 715                 if (conflict != parent) {
 716                         parent = conflict;
 717                         if (!(conflict->flags & IORESOURCE_BUSY))
 718                                 continue;
 719                 }
 720
 721                 /* Uhhuh, that didn't work out.. */
 722                 kfree(res);
 723                 res = NULL;
 724                 break;
 725         }
 726         write_unlock(&resource_lock);
 727         return res;
 728 }
 729 EXPORT_SYMBOL(__request_region);
 730
 731 /**
 732  * __check_region - check if a resource region is busy or free
 733  * @parent: parent resource descriptor
 734  * @start: resource start address
 735  * @n: resource region size
 736  *
 737  * Returns 0 if the region is free at the moment it is checked,
 738  * returns %-EBUSY if the region is busy.
 739  *
 740  * NOTE:
 741  * This function is deprecated because its use is racy.
 742  * Even if it returns 0, a subsequent call to request_region()
 743  * may fail because another driver etc. just allocated the region.
 744  * Do NOT use it.  It will be removed from the kernel.
 745  */
 746 int __check_region(struct resource *parent, resource_size_t start,
 747                         resource_size_t n)
 748 {
 749         struct resource * res;
 750
 751         res = __request_region(parent, start, n, "check-region", 0);
 752         if (!res)
 753                 return -EBUSY;
 754
 755         release_resource(res);
 756         kfree(res);
 757         return 0;
 758 }
 759 EXPORT_SYMBOL(__check_region);
 760
 761 /**
 762  * __release_region - release a previously reserved resource region
 763  * @parent: parent resource descriptor
 764  * @start: resource start address
 765  * @n: resource region size
 766  *
 767  * The described resource region must match a currently busy region.
 768  */
 769 void __release_region(struct resource *parent, resource_size_t start,
 770                         resource_size_t n)
 771 {
 772         struct resource **p;
 773         resource_size_t end;
 774
 775         p = &parent->child;
 776         end = start + n - 1;
 777
 778         write_lock(&resource_lock);
 779
 780         for (;;) {
 781                 struct resource *res = *p;
 782
 783                 if (!res)
 784                         break;
 785                 if (res->start <= start && res->end >= end) {
 786                         if (!(res->flags & IORESOURCE_BUSY)) {
 787                                 p = &res->child;
 788                                 continue;
 789                         }
 790                         if (res->start != start || res->end != end)
 791                                 break;
 792                         *p = res->sibling;
 793                         write_unlock(&resource_lock);
 794                         kfree(res);
 795                         return;
 796                 }
 797                 p = &res->sibling;
 798         }
 799
 800         write_unlock(&resource_lock);
 801
 802         printk(KERN_WARNING "Trying to free nonexistent resource "
 803                 "<%016llx-%016llx>\n", (unsigned long long)start,
 804                 (unsigned long long)end);
 805 }
 806 EXPORT_SYMBOL(__release_region);
 807
 808 /*
 809  * Managed region resource
 810  */
 811 struct region_devres {
 812         struct resource *parent;
 813         resource_size_t start;
 814         resource_size_t n;
 815 };
 816
 817 static void devm_region_release(struct device *dev, void *res)
 818 {
 819         struct region_devres *this = res;
 820
 821         __release_region(this->parent, this->start, this->n);
 822 }
 823
 824 static int devm_region_match(struct device *dev, void *res, void *match_data)
 825 {
 826         struct region_devres *this = res, *match = match_data;
 827
 828         return this->parent == match->parent &&
 829                 this->start == match->start && this->n == match->n;
 830 }
 831
 832 struct resource * __devm_request_region(struct device *dev,
 833                                 struct resource *parent, resource_size_t start,
 834                                 resource_size_t n, const char *name)
 835 {
 836         struct region_devres *dr = NULL;
 837         struct resource *res;
 838
 839         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
 840                           GFP_KERNEL);
 841         if (!dr)
 842                 return NULL;
 843
 844         dr->parent = parent;
 845         dr->start = start;
 846         dr->n = n;
 847
 848         res = __request_region(parent, start, n, name, 0);
 849         if (res)
 850                 devres_add(dev, dr);
 851         else
 852                 devres_free(dr);
 853
 854         return res;
 855 }
 856 EXPORT_SYMBOL(__devm_request_region);
 857
 858 void __devm_release_region(struct device *dev, struct resource *parent,
 859                            resource_size_t start, resource_size_t n)
 860 {
 861         struct region_devres match_data = { parent, start, n };
 862
 863         __release_region(parent, start, n);
 864         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
 865                                &match_data));
 866 }
 867 EXPORT_SYMBOL(__devm_release_region);
 868
 869 /*
 870  * Called from init/main.c to reserve IO ports.
 871  */
 872 #define MAXRESERVE 4
 873 static int __init reserve_setup(char *str)
 874 {
 875         static int reserved;
 876         static struct resource reserve[MAXRESERVE];
 877
 878         for (;;) {
 879                 unsigned int io_start, io_num;
 880                 int x = reserved;
 881
 882                 if (get_option (&str, &io_start) != 2)
 883                         break;
 884                 if (get_option (&str, &io_num)   == 0)
 885                         break;
 886                 if (x < MAXRESERVE) {
 887                         struct resource *res = reserve + x;
 888                         res->name = "reserved";
 889                         res->start = io_start;
 890                         res->end = io_start + io_num - 1;
 891                         res->flags = IORESOURCE_BUSY;
 892                         res->child = NULL;
 893                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
 894                                 reserved = x+1;
 895                 }
 896         }
 897         return 1;
 898 }
 899
 900 __setup("reserve=", reserve_setup);
 901
 902 /*
 903  * Check if the requested addr and size spans more than any slot in the
 904  * iomem resource tree.
 905  */
 906 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 907 {
 908         struct resource *p = &iomem_resource;
 909         int err = 0;
 910         loff_t l;
 911
 912         read_lock(&resource_lock);
 913         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 914                 /*
 915                  * We can probably skip the resources without
 916                  * IORESOURCE_IO attribute?
 917                  */
 918                 if (p->start >= addr + size)
 919                         continue;
 920                 if (p->end < addr)
 921                         continue;
 922                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
 923                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
 924                         continue;
 925                 /*
 926                  * if a resource is "BUSY", it's not a hardware resource
 927                  * but a driver mapping of such a resource; we don't want
 928                  * to warn for those; some drivers legitimately map only
 929                  * partial hardware resources. (example: vesafb)
 930                  */
 931                 if (p->flags & IORESOURCE_BUSY)
 932                         continue;
 933
 934                 printk(KERN_WARNING "resource map sanity check conflict: "
 935                        "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
 936                        (unsigned long long)addr,
 937                        (unsigned long long)(addr + size - 1),
 938                        (unsigned long long)p->start,
 939                        (unsigned long long)p->end,
 940                        p->name);
 941                 err = -1;
 942                 break;
 943         }
 944         read_unlock(&resource_lock);
 945
 946         return err;
 947 }
 948
 949 #ifdef CONFIG_STRICT_DEVMEM
 950 static int strict_iomem_checks = 1;
 951 #else
 952 static int strict_iomem_checks;
 953 #endif
 954
 955 /*
 956  * check if an address is reserved in the iomem resource tree
 957  * returns 1 if reserved, 0 if not reserved.
 958  */
 959 int iomem_is_exclusive(u64 addr)
 960 {
 961         struct resource *p = &iomem_resource;
 962         int err = 0;
 963         loff_t l;
 964         int size = PAGE_SIZE;
 965
 966         if (!strict_iomem_checks)
 967                 return 0;
 968
 969         addr = addr & PAGE_MASK;
 970
 971         read_lock(&resource_lock);
 972         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 973                 /*
 974                  * We can probably skip the resources without
 975                  * IORESOURCE_IO attribute?
 976                  */
 977                 if (p->start >= addr + size)
 978                         break;
 979                 if (p->end < addr)
 980                         continue;
 981                 if (p->flags & IORESOURCE_BUSY &&
 982                      p->flags & IORESOURCE_EXCLUSIVE) {
 983                         err = 1;
 984                         break;
 985                 }
 986         }
 987         read_unlock(&resource_lock);
 988
 989         return err;
 990 }
 991
 992 static int __init strict_iomem(char *str)
 993 {
 994         if (strstr(str, "relaxed"))
 995                 strict_iomem_checks = 0;
 996         if (strstr(str, "strict"))
 997                 strict_iomem_checks = 1;
 998         return 1;
 999 }
1000
1001 __setup("iomem=", strict_iomem);