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