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