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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/export.h>
  13 #include <linux/errno.h>
  14 #include <linux/ioport.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/fs.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/sched.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/device.h>
  23 #include <linux/pfn.h>
  24 #include <asm/io.h>
  25
  26
  27 struct resource ioport_resource = {
  28         .name   = "PCI IO",
  29         .start  = 0,
  30         .end    = IO_SPACE_LIMIT,
  31         .flags  = IORESOURCE_IO,
  32 };
  33 EXPORT_SYMBOL(ioport_resource);
  34
  35 struct resource iomem_resource = {
  36         .name   = "PCI mem",
  37         .start  = 0,
  38         .end    = -1,
  39         .flags  = IORESOURCE_MEM,
  40 };
  41 EXPORT_SYMBOL(iomem_resource);
  42
  43 /* constraints to be met while allocating resources */
  44 struct resource_constraint {
  45         resource_size_t min, max, align;
  46         resource_size_t (*alignf)(void *, const struct resource *,
  47                         resource_size_t, resource_size_t);
  48         void *alignf_data;
  49 };
  50
  51 static DEFINE_RWLOCK(resource_lock);
  52
  53 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  54 {
  55         struct resource *p = v;
  56         (*pos)++;
  57         if (p->child)
  58                 return p->child;
  59         while (!p->sibling && p->parent)
  60                 p = p->parent;
  61         return p->sibling;
  62 }
  63
  64 #ifdef CONFIG_PROC_FS
  65
  66 enum { MAX_IORES_LEVEL = 5 };
  67
  68 static void *r_start(struct seq_file *m, loff_t *pos)
  69         __acquires(resource_lock)
  70 {
  71         struct resource *p = m->private;
  72         loff_t l = 0;
  73         read_lock(&resource_lock);
  74         for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  75                 ;
  76         return p;
  77 }
  78
  79 static void r_stop(struct seq_file *m, void *v)
  80         __releases(resource_lock)
  81 {
  82         read_unlock(&resource_lock);
  83 }
  84
  85 static int r_show(struct seq_file *m, void *v)
  86 {
  87         struct resource *root = m->private;
  88         struct resource *r = v, *p;
  89         int width = root->end < 0x10000 ? 4 : 8;
  90         int depth;
  91
  92         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
  93                 if (p->parent == root)
  94                         break;
  95         seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
  96                         depth * 2, "",
  97                         width, (unsigned long long) r->start,
  98                         width, (unsigned long long) r->end,
  99                         r->name ? r->name : "<BAD>");
 100         return 0;
 101 }
 102
 103 static const struct seq_operations resource_op = {
 104         .start  = r_start,
 105         .next   = r_next,
 106         .stop   = r_stop,
 107         .show   = r_show,
 108 };
 109
 110 static int ioports_open(struct inode *inode, struct file *file)
 111 {
 112         int res = seq_open(file, &resource_op);
 113         if (!res) {
 114                 struct seq_file *m = file->private_data;
 115                 m->private = &ioport_resource;
 116         }
 117         return res;
 118 }
 119
 120 static int iomem_open(struct inode *inode, struct file *file)
 121 {
 122         int res = seq_open(file, &resource_op);
 123         if (!res) {
 124                 struct seq_file *m = file->private_data;
 125                 m->private = &iomem_resource;
 126         }
 127         return res;
 128 }
 129
 130 static const struct file_operations proc_ioports_operations = {
 131         .open           = ioports_open,
 132         .read           = seq_read,
 133         .llseek         = seq_lseek,
 134         .release        = seq_release,
 135 };
 136
 137 static const struct file_operations proc_iomem_operations = {
 138         .open           = iomem_open,
 139         .read           = seq_read,
 140         .llseek         = seq_lseek,
 141         .release        = seq_release,
 142 };
 143
 144 static int __init ioresources_init(void)
 145 {
 146         proc_create("ioports", 0, NULL, &proc_ioports_operations);
 147         proc_create("iomem", 0, NULL, &proc_iomem_operations);
 148         return 0;
 149 }
 150 __initcall(ioresources_init);
 151
 152 #endif /* CONFIG_PROC_FS */
 153
 154 /* Return the conflict entry if you can't request it */
 155 static struct resource * __request_resource(struct resource *root, struct resource *new)
 156 {
 157         resource_size_t start = new->start;
 158         resource_size_t end = new->end;
 159         struct resource *tmp, **p;
 160
 161         if (end < start)
 162                 return root;
 163         if (start < root->start)
 164                 return root;
 165         if (end > root->end)
 166                 return root;
 167         p = &root->child;
 168         for (;;) {
 169                 tmp = *p;
 170                 if (!tmp || tmp->start > end) {
 171                         new->sibling = tmp;
 172                         *p = new;
 173                         new->parent = root;
 174                         return NULL;
 175                 }
 176                 p = &tmp->sibling;
 177                 if (tmp->end < start)
 178                         continue;
 179                 return tmp;
 180         }
 181 }
 182
 183 static int __release_resource(struct resource *old)
 184 {
 185         struct resource *tmp, **p;
 186
 187         p = &old->parent->child;
 188         for (;;) {
 189                 tmp = *p;
 190                 if (!tmp)
 191                         break;
 192                 if (tmp == old) {
 193                         *p = tmp->sibling;
 194                         old->parent = NULL;
 195                         return 0;
 196                 }
 197                 p = &tmp->sibling;
 198         }
 199         return -EINVAL;
 200 }
 201
 202 static void __release_child_resources(struct resource *r)
 203 {
 204         struct resource *tmp, *p;
 205         resource_size_t size;
 206
 207         p = r->child;
 208         r->child = NULL;
 209         while (p) {
 210                 tmp = p;
 211                 p = p->sibling;
 212
 213                 tmp->parent = NULL;
 214                 tmp->sibling = NULL;
 215                 __release_child_resources(tmp);
 216
 217                 printk(KERN_DEBUG "release child resource %pR\n", tmp);
 218                 /* need to restore size, and keep flags */
 219                 size = resource_size(tmp);
 220                 tmp->start = 0;
 221                 tmp->end = size - 1;
 222         }
 223 }
 224
 225 void release_child_resources(struct resource *r)
 226 {
 227         write_lock(&resource_lock);
 228         __release_child_resources(r);
 229         write_unlock(&resource_lock);
 230 }
 231
 232 /**
 233  * request_resource_conflict - request and reserve an I/O or memory resource
 234  * @root: root resource descriptor
 235  * @new: resource descriptor desired by caller
 236  *
 237  * Returns 0 for success, conflict resource on error.
 238  */
 239 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
 240 {
 241         struct resource *conflict;
 242
 243         write_lock(&resource_lock);
 244         conflict = __request_resource(root, new);
 245         write_unlock(&resource_lock);
 246         return conflict;
 247 }
 248
 249 /**
 250  * request_resource - request and reserve an I/O or memory resource
 251  * @root: root resource descriptor
 252  * @new: resource descriptor desired by caller
 253  *
 254  * Returns 0 for success, negative error code on error.
 255  */
 256 int request_resource(struct resource *root, struct resource *new)
 257 {
 258         struct resource *conflict;
 259
 260         conflict = request_resource_conflict(root, new);
 261         return conflict ? -EBUSY : 0;
 262 }
 263
 264 EXPORT_SYMBOL(request_resource);
 265
 266 /**
 267  * release_resource - release a previously reserved resource
 268  * @old: resource pointer
 269  */
 270 int release_resource(struct resource *old)
 271 {
 272         int retval;
 273
 274         write_lock(&resource_lock);
 275         retval = __release_resource(old);
 276         write_unlock(&resource_lock);
 277         return retval;
 278 }
 279
 280 EXPORT_SYMBOL(release_resource);
 281
 282 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 283 /*
 284  * Finds the lowest memory reosurce exists within [res->start.res->end)
 285  * the caller must specify res->start, res->end, res->flags and "name".
 286  * If found, returns 0, res is overwritten, if not found, returns -1.
 287  */
 288 static int find_next_system_ram(struct resource *res, char *name)
 289 {
 290         resource_size_t start, end;
 291         struct resource *p;
 292
 293         BUG_ON(!res);
 294
 295         start = res->start;
 296         end = res->end;
 297         BUG_ON(start >= end);
 298
 299         read_lock(&resource_lock);
 300         for (p = iomem_resource.child; p ; p = p->sibling) {
 301                 /* system ram is just marked as IORESOURCE_MEM */
 302                 if (p->flags != res->flags)
 303                         continue;
 304                 if (name && strcmp(p->name, name))
 305                         continue;
 306                 if (p->start > end) {
 307                         p = NULL;
 308                         break;
 309                 }
 310                 if ((p->end >= start) && (p->start < end))
 311                         break;
 312         }
 313         read_unlock(&resource_lock);
 314         if (!p)
 315                 return -1;
 316         /* copy data */
 317         if (res->start < p->start)
 318                 res->start = p->start;
 319         if (res->end > p->end)
 320                 res->end = p->end;
 321         return 0;
 322 }
 323
 324 /*
 325  * This function calls callback against all memory range of "System RAM"
 326  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 327  * Now, this function is only for "System RAM".
 328  */
 329 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 330                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 331 {
 332         struct resource res;
 333         unsigned long pfn, end_pfn;
 334         u64 orig_end;
 335         int ret = -1;
 336
 337         res.start = (u64) start_pfn << PAGE_SHIFT;
 338         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 339         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 340         orig_end = res.end;
 341         while ((res.start < res.end) &&
 342                 (find_next_system_ram(&res, "System RAM") >= 0)) {
 343                 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 344                 end_pfn = (res.end + 1) >> PAGE_SHIFT;
 345                 if (end_pfn > pfn)
 346                         ret = (*func)(pfn, end_pfn - pfn, arg);
 347                 if (ret)
 348                         break;
 349                 res.start = res.end + 1;
 350                 res.end = orig_end;
 351         }
 352         return ret;
 353 }
 354
 355 #endif
 356
 357 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 358 {
 359         return 1;
 360 }
 361 /*
 362  * This generic page_is_ram() returns true if specified address is
 363  * registered as "System RAM" in iomem_resource list.
 364  */
 365 int __weak page_is_ram(unsigned long pfn)
 366 {
 367         return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 368 }
 369
 370 void __weak arch_remove_reservations(struct resource *avail)
 371 {
 372 }
 373
 374 static resource_size_t simple_align_resource(void *data,
 375                                              const struct resource *avail,
 376                                              resource_size_t size,
 377                                              resource_size_t align)
 378 {
 379         return avail->start;
 380 }
 381
 382 static void resource_clip(struct resource *res, resource_size_t min,
 383                           resource_size_t max)
 384 {
 385         if (res->start < min)
 386                 res->start = min;
 387         if (res->end > max)
 388                 res->end = max;
 389 }
 390
 391 static bool resource_contains(struct resource *res1, struct resource *res2)
 392 {
 393         return res1->start <= res2->start && res1->end >= res2->end;
 394 }
 395
 396 /*
 397  * Find empty slot in the resource tree with the given range and
 398  * alignment constraints
 399  */
 400 static int __find_resource(struct resource *root, struct resource *old,
 401                          struct resource *new,
 402                          resource_size_t  size,
 403                          struct resource_constraint *constraint)
 404 {
 405         struct resource *this = root->child;
 406         struct resource tmp = *new, avail, alloc;
 407
 408         tmp.flags = new->flags;
 409         tmp.start = root->start;
 410         /*
 411          * Skip past an allocated resource that starts at 0, since the assignment
 412          * of this->start - 1 to tmp->end below would cause an underflow.
 413          */
 414         if (this && this->start == root->start) {
 415                 tmp.start = (this == old) ? old->start : this->end + 1;
 416                 this = this->sibling;
 417         }
 418         for(;;) {
 419                 if (this)
 420                         tmp.end = (this == old) ?  this->end : this->start - 1;
 421                 else
 422                         tmp.end = root->end;
 423
 424                 if (tmp.end < tmp.start)
 425                         goto next;
 426
 427                 resource_clip(&tmp, constraint->min, constraint->max);
 428                 arch_remove_reservations(&tmp);
 429
 430                 /* Check for overflow after ALIGN() */
 431                 avail = *new;
 432                 avail.start = ALIGN(tmp.start, constraint->align);
 433                 avail.end = tmp.end;
 434                 if (avail.start >= tmp.start) {
 435                         alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 436                                         size, constraint->align);
 437                         alloc.end = alloc.start + size - 1;
 438                         if (resource_contains(&avail, &alloc)) {
 439                                 new->start = alloc.start;
 440                                 new->end = alloc.end;
 441                                 return 0;
 442                         }
 443                 }
 444
 445 next:           if (!this || this->end == root->end)
 446                         break;
 447
 448                 if (this != old)
 449                         tmp.start = this->end + 1;
 450                 this = this->sibling;
 451         }
 452         return -EBUSY;
 453 }
 454
 455 /*
 456  * Find empty slot in the resource tree given range and alignment.
 457  */
 458 static int find_resource(struct resource *root, struct resource *new,
 459                         resource_size_t size,
 460                         struct resource_constraint  *constraint)
 461 {
 462         return  __find_resource(root, NULL, new, size, constraint);
 463 }
 464
 465 /**
 466  * reallocate_resource - allocate a slot in the resource tree given range & alignment.
 467  *      The resource will be relocated if the new size cannot be reallocated in the
 468  *      current location.
 469  *
 470  * @root: root resource descriptor
 471  * @old:  resource descriptor desired by caller
 472  * @newsize: new size of the resource descriptor
 473  * @constraint: the size and alignment constraints to be met.
 474  */
 475 int reallocate_resource(struct resource *root, struct resource *old,
 476                         resource_size_t newsize,
 477                         struct resource_constraint  *constraint)
 478 {
 479         int err=0;
 480         struct resource new = *old;
 481         struct resource *conflict;
 482
 483         write_lock(&resource_lock);
 484
 485         if ((err = __find_resource(root, old, &new, newsize, constraint)))
 486                 goto out;
 487
 488         if (resource_contains(&new, old)) {
 489                 old->start = new.start;
 490                 old->end = new.end;
 491                 goto out;
 492         }
 493
 494         if (old->child) {
 495                 err = -EBUSY;
 496                 goto out;
 497         }
 498
 499         if (resource_contains(old, &new)) {
 500                 old->start = new.start;
 501                 old->end = new.end;
 502         } else {
 503                 __release_resource(old);
 504                 *old = new;
 505                 conflict = __request_resource(root, old);
 506                 BUG_ON(conflict);
 507         }
 508 out:
 509         write_unlock(&resource_lock);
 510         return err;
 511 }
 512
 513
 514 /**
 515  * allocate_resource - allocate empty slot in the resource tree given range & alignment.
 516  *      The resource will be reallocated with a new size if it was already allocated
 517  * @root: root resource descriptor
 518  * @new: resource descriptor desired by caller
 519  * @size: requested resource region size
 520  * @min: minimum boundary to allocate
 521  * @max: maximum boundary to allocate
 522  * @align: alignment requested, in bytes
 523  * @alignf: alignment function, optional, called if not NULL
 524  * @alignf_data: arbitrary data to pass to the @alignf function
 525  */
 526 int allocate_resource(struct resource *root, struct resource *new,
 527                       resource_size_t size, resource_size_t min,
 528                       resource_size_t max, resource_size_t align,
 529                       resource_size_t (*alignf)(void *,
 530                                                 const struct resource *,
 531                                                 resource_size_t,
 532                                                 resource_size_t),
 533                       void *alignf_data)
 534 {
 535         int err;
 536         struct resource_constraint constraint;
 537
 538         if (!alignf)
 539                 alignf = simple_align_resource;
 540
 541         constraint.min = min;
 542         constraint.max = max;
 543         constraint.align = align;
 544         constraint.alignf = alignf;
 545         constraint.alignf_data = alignf_data;
 546
 547         if ( new->parent ) {
 548                 /* resource is already allocated, try reallocating with
 549                    the new constraints */
 550                 return reallocate_resource(root, new, size, &constraint);
 551         }
 552
 553         write_lock(&resource_lock);
 554         err = find_resource(root, new, size, &constraint);
 555         if (err >= 0 && __request_resource(root, new))
 556                 err = -EBUSY;
 557         write_unlock(&resource_lock);
 558         return err;
 559 }
 560
 561 EXPORT_SYMBOL(allocate_resource);
 562
 563 /**
 564  * lookup_resource - find an existing resource by a resource start address
 565  * @root: root resource descriptor
 566  * @start: resource start address
 567  *
 568  * Returns a pointer to the resource if found, NULL otherwise
 569  */
 570 struct resource *lookup_resource(struct resource *root, resource_size_t start)
 571 {
 572         struct resource *res;
 573
 574         read_lock(&resource_lock);
 575         for (res = root->child; res; res = res->sibling) {
 576                 if (res->start == start)
 577                         break;
 578         }
 579         read_unlock(&resource_lock);
 580
 581         return res;
 582 }
 583
 584 /*
 585  * Insert a resource into the resource tree. If successful, return NULL,
 586  * otherwise return the conflicting resource (compare to __request_resource())
 587  */
 588 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 589 {
 590         struct resource *first, *next;
 591
 592         for (;; parent = first) {
 593                 first = __request_resource(parent, new);
 594                 if (!first)
 595                         return first;
 596
 597                 if (first == parent)
 598                         return first;
 599                 if (WARN_ON(first == new))      /* duplicated insertion */
 600                         return first;
 601
 602                 if ((first->start > new->start) || (first->end < new->end))
 603                         break;
 604                 if ((first->start == new->start) && (first->end == new->end))
 605                         break;
 606         }
 607
 608         for (next = first; ; next = next->sibling) {
 609                 /* Partial overlap? Bad, and unfixable */
 610                 if (next->start < new->start || next->end > new->end)
 611                         return next;
 612                 if (!next->sibling)
 613                         break;
 614                 if (next->sibling->start > new->end)
 615                         break;
 616         }
 617
 618         new->parent = parent;
 619         new->sibling = next->sibling;
 620         new->child = first;
 621
 622         next->sibling = NULL;
 623         for (next = first; next; next = next->sibling)
 624                 next->parent = new;
 625
 626         if (parent->child == first) {
 627                 parent->child = new;
 628         } else {
 629                 next = parent->child;
 630                 while (next->sibling != first)
 631                         next = next->sibling;
 632                 next->sibling = new;
 633         }
 634         return NULL;
 635 }
 636
 637 /**
 638  * insert_resource_conflict - Inserts resource in the resource tree
 639  * @parent: parent of the new resource
 640  * @new: new resource to insert
 641  *
 642  * Returns 0 on success, conflict resource if the resource can't be inserted.
 643  *
 644  * This function is equivalent to request_resource_conflict when no conflict
 645  * happens. If a conflict happens, and the conflicting resources
 646  * entirely fit within the range of the new resource, then the new
 647  * resource is inserted and the conflicting resources become children of
 648  * the new resource.
 649  */
 650 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 651 {
 652         struct resource *conflict;
 653
 654         write_lock(&resource_lock);
 655         conflict = __insert_resource(parent, new);
 656         write_unlock(&resource_lock);
 657         return conflict;
 658 }
 659
 660 /**
 661  * insert_resource - Inserts a resource in the resource tree
 662  * @parent: parent of the new resource
 663  * @new: new resource to insert
 664  *
 665  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 666  */
 667 int insert_resource(struct resource *parent, struct resource *new)
 668 {
 669         struct resource *conflict;
 670
 671         conflict = insert_resource_conflict(parent, new);
 672         return conflict ? -EBUSY : 0;
 673 }
 674
 675 /**
 676  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 677  * @root: root resource descriptor
 678  * @new: new resource to insert
 679  *
 680  * Insert a resource into the resource tree, possibly expanding it in order
 681  * to make it encompass any conflicting resources.
 682  */
 683 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 684 {
 685         if (new->parent)
 686                 return;
 687
 688         write_lock(&resource_lock);
 689         for (;;) {
 690                 struct resource *conflict;
 691
 692                 conflict = __insert_resource(root, new);
 693                 if (!conflict)
 694                         break;
 695                 if (conflict == root)
 696                         break;
 697
 698                 /* Ok, expand resource to cover the conflict, then try again .. */
 699                 if (conflict->start < new->start)
 700                         new->start = conflict->start;
 701                 if (conflict->end > new->end)
 702                         new->end = conflict->end;
 703
 704                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 705         }
 706         write_unlock(&resource_lock);
 707 }
 708
 709 /**
 710  * adjust_resource - modify a resource's start and size
 711  * @res: resource to modify
 712  * @start: new start value
 713  * @size: new size
 714  *
 715  * Given an existing resource, change its start and size to match the
 716  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 717  * Existing children of the resource are assumed to be immutable.
 718  */
 719 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
 720 {
 721         struct resource *tmp, *parent = res->parent;
 722         resource_size_t end = start + size - 1;
 723         int result = -EBUSY;
 724
 725         write_lock(&resource_lock);
 726
 727         if (!parent)
 728                 goto skip;
 729
 730         if ((start < parent->start) || (end > parent->end))
 731                 goto out;
 732
 733         if (res->sibling && (res->sibling->start <= end))
 734                 goto out;
 735
 736         tmp = parent->child;
 737         if (tmp != res) {
 738                 while (tmp->sibling != res)
 739                         tmp = tmp->sibling;
 740                 if (start <= tmp->end)
 741                         goto out;
 742         }
 743
 744 skip:
 745         for (tmp = res->child; tmp; tmp = tmp->sibling)
 746                 if ((tmp->start < start) || (tmp->end > end))
 747                         goto out;
 748
 749         res->start = start;
 750         res->end = end;
 751         result = 0;
 752
 753  out:
 754         write_unlock(&resource_lock);
 755         return result;
 756 }
 757 EXPORT_SYMBOL(adjust_resource);
 758
 759 static void __init __reserve_region_with_split(struct resource *root,
 760                 resource_size_t start, resource_size_t end,
 761                 const char *name)
 762 {
 763         struct resource *parent = root;
 764         struct resource *conflict;
 765         struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
 766         struct resource *next_res = NULL;
 767
 768         if (!res)
 769                 return;
 770
 771         res->name = name;
 772         res->start = start;
 773         res->end = end;
 774         res->flags = IORESOURCE_BUSY;
 775
 776         while (1) {
 777
 778                 conflict = __request_resource(parent, res);
 779                 if (!conflict) {
 780                         if (!next_res)
 781                                 break;
 782                         res = next_res;
 783                         next_res = NULL;
 784                         continue;
 785                 }
 786
 787                 /* conflict covered whole area */
 788                 if (conflict->start <= res->start &&
 789                                 conflict->end >= res->end) {
 790                         kfree(res);
 791                         WARN_ON(next_res);
 792                         break;
 793                 }
 794
 795                 /* failed, split and try again */
 796                 if (conflict->start > res->start) {
 797                         end = res->end;
 798                         res->end = conflict->start - 1;
 799                         if (conflict->end < end) {
 800                                 next_res = kzalloc(sizeof(*next_res),
 801                                                 GFP_ATOMIC);
 802                                 if (!next_res) {
 803                                         kfree(res);
 804                                         break;
 805                                 }
 806                                 next_res->name = name;
 807                                 next_res->start = conflict->end + 1;
 808                                 next_res->end = end;
 809                                 next_res->flags = IORESOURCE_BUSY;
 810                         }
 811                 } else {
 812                         res->start = conflict->end + 1;
 813                 }
 814         }
 815
 816 }
 817
 818 void __init reserve_region_with_split(struct resource *root,
 819                 resource_size_t start, resource_size_t end,
 820                 const char *name)
 821 {
 822         int abort = 0;
 823
 824         write_lock(&resource_lock);
 825         if (root->start > start || root->end < end) {
 826                 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
 827                        (unsigned long long)start, (unsigned long long)end,
 828                        root);
 829                 if (start > root->end || end < root->start)
 830                         abort = 1;
 831                 else {
 832                         if (end > root->end)
 833                                 end = root->end;
 834                         if (start < root->start)
 835                                 start = root->start;
 836                         pr_err("fixing request to [0x%llx-0x%llx]\n",
 837                                (unsigned long long)start,
 838                                (unsigned long long)end);
 839                 }
 840                 dump_stack();
 841         }
 842         if (!abort)
 843                 __reserve_region_with_split(root, start, end, name);
 844         write_unlock(&resource_lock);
 845 }
 846
 847 /**
 848  * resource_alignment - calculate resource's alignment
 849  * @res: resource pointer
 850  *
 851  * Returns alignment on success, 0 (invalid alignment) on failure.
 852  */
 853 resource_size_t resource_alignment(struct resource *res)
 854 {
 855         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 856         case IORESOURCE_SIZEALIGN:
 857                 return resource_size(res);
 858         case IORESOURCE_STARTALIGN:
 859                 return res->start;
 860         default:
 861                 return 0;
 862         }
 863 }
 864
 865 /*
 866  * This is compatibility stuff for IO resources.
 867  *
 868  * Note how this, unlike the above, knows about
 869  * the IO flag meanings (busy etc).
 870  *
 871  * request_region creates a new busy region.
 872  *
 873  * check_region returns non-zero if the area is already busy.
 874  *
 875  * release_region releases a matching busy region.
 876  */
 877
 878 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
 879
 880 /**
 881  * __request_region - create a new busy resource region
 882  * @parent: parent resource descriptor
 883  * @start: resource start address
 884  * @n: resource region size
 885  * @name: reserving caller's ID string
 886  * @flags: IO resource flags
 887  */
 888 struct resource * __request_region(struct resource *parent,
 889                                    resource_size_t start, resource_size_t n,
 890                                    const char *name, int flags)
 891 {
 892         DECLARE_WAITQUEUE(wait, current);
 893         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 894
 895         if (!res)
 896                 return NULL;
 897
 898         res->name = name;
 899         res->start = start;
 900         res->end = start + n - 1;
 901         res->flags = IORESOURCE_BUSY;
 902         res->flags |= flags;
 903
 904         write_lock(&resource_lock);
 905
 906         for (;;) {
 907                 struct resource *conflict;
 908
 909                 conflict = __request_resource(parent, res);
 910                 if (!conflict)
 911                         break;
 912                 if (conflict != parent) {
 913                         parent = conflict;
 914                         if (!(conflict->flags & IORESOURCE_BUSY))
 915                                 continue;
 916                 }
 917                 if (conflict->flags & flags & IORESOURCE_MUXED) {
 918                         add_wait_queue(&muxed_resource_wait, &wait);
 919                         write_unlock(&resource_lock);
 920                         set_current_state(TASK_UNINTERRUPTIBLE);
 921                         schedule();
 922                         remove_wait_queue(&muxed_resource_wait, &wait);
 923                         write_lock(&resource_lock);
 924                         continue;
 925                 }
 926                 /* Uhhuh, that didn't work out.. */
 927                 kfree(res);
 928                 res = NULL;
 929                 break;
 930         }
 931         write_unlock(&resource_lock);
 932         return res;
 933 }
 934 EXPORT_SYMBOL(__request_region);
 935
 936 /**
 937  * __check_region - check if a resource region is busy or free
 938  * @parent: parent resource descriptor
 939  * @start: resource start address
 940  * @n: resource region size
 941  *
 942  * Returns 0 if the region is free at the moment it is checked,
 943  * returns %-EBUSY if the region is busy.
 944  *
 945  * NOTE:
 946  * This function is deprecated because its use is racy.
 947  * Even if it returns 0, a subsequent call to request_region()
 948  * may fail because another driver etc. just allocated the region.
 949  * Do NOT use it.  It will be removed from the kernel.
 950  */
 951 int __check_region(struct resource *parent, resource_size_t start,
 952                         resource_size_t n)
 953 {
 954         struct resource * res;
 955
 956         res = __request_region(parent, start, n, "check-region", 0);
 957         if (!res)
 958                 return -EBUSY;
 959
 960         release_resource(res);
 961         kfree(res);
 962         return 0;
 963 }
 964 EXPORT_SYMBOL(__check_region);
 965
 966 /**
 967  * __release_region - release a previously reserved resource region
 968  * @parent: parent resource descriptor
 969  * @start: resource start address
 970  * @n: resource region size
 971  *
 972  * The described resource region must match a currently busy region.
 973  */
 974 void __release_region(struct resource *parent, resource_size_t start,
 975                         resource_size_t n)
 976 {
 977         struct resource **p;
 978         resource_size_t end;
 979
 980         p = &parent->child;
 981         end = start + n - 1;
 982
 983         write_lock(&resource_lock);
 984
 985         for (;;) {
 986                 struct resource *res = *p;
 987
 988                 if (!res)
 989                         break;
 990                 if (res->start <= start && res->end >= end) {
 991                         if (!(res->flags & IORESOURCE_BUSY)) {
 992                                 p = &res->child;
 993                                 continue;
 994                         }
 995                         if (res->start != start || res->end != end)
 996                                 break;
 997                         *p = res->sibling;
 998                         write_unlock(&resource_lock);
 999                         if (res->flags & IORESOURCE_MUXED)
1000                                 wake_up(&muxed_resource_wait);
1001                         kfree(res);
1002                         return;
1003                 }
1004                 p = &res->sibling;
1005         }
1006
1007         write_unlock(&resource_lock);
1008
1009         printk(KERN_WARNING "Trying to free nonexistent resource "
1010                 "<%016llx-%016llx>\n", (unsigned long long)start,
1011                 (unsigned long long)end);
1012 }
1013 EXPORT_SYMBOL(__release_region);
1014
1015 /*
1016  * Managed region resource
1017  */
1018 struct region_devres {
1019         struct resource *parent;
1020         resource_size_t start;
1021         resource_size_t n;
1022 };
1023
1024 static void devm_region_release(struct device *dev, void *res)
1025 {
1026         struct region_devres *this = res;
1027
1028         __release_region(this->parent, this->start, this->n);
1029 }
1030
1031 static int devm_region_match(struct device *dev, void *res, void *match_data)
1032 {
1033         struct region_devres *this = res, *match = match_data;
1034
1035         return this->parent == match->parent &&
1036                 this->start == match->start && this->n == match->n;
1037 }
1038
1039 struct resource * __devm_request_region(struct device *dev,
1040                                 struct resource *parent, resource_size_t start,
1041                                 resource_size_t n, const char *name)
1042 {
1043         struct region_devres *dr = NULL;
1044         struct resource *res;
1045
1046         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1047                           GFP_KERNEL);
1048         if (!dr)
1049                 return NULL;
1050
1051         dr->parent = parent;
1052         dr->start = start;
1053         dr->n = n;
1054
1055         res = __request_region(parent, start, n, name, 0);
1056         if (res)
1057                 devres_add(dev, dr);
1058         else
1059                 devres_free(dr);
1060
1061         return res;
1062 }
1063 EXPORT_SYMBOL(__devm_request_region);
1064
1065 void __devm_release_region(struct device *dev, struct resource *parent,
1066                            resource_size_t start, resource_size_t n)
1067 {
1068         struct region_devres match_data = { parent, start, n };
1069
1070         __release_region(parent, start, n);
1071         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1072                                &match_data));
1073 }
1074 EXPORT_SYMBOL(__devm_release_region);
1075
1076 /*
1077  * Called from init/main.c to reserve IO ports.
1078  */
1079 #define MAXRESERVE 4
1080 static int __init reserve_setup(char *str)
1081 {
1082         static int reserved;
1083         static struct resource reserve[MAXRESERVE];
1084
1085         for (;;) {
1086                 unsigned int io_start, io_num;
1087                 int x = reserved;
1088
1089                 if (get_option (&str, &io_start) != 2)
1090                         break;
1091                 if (get_option (&str, &io_num)   == 0)
1092                         break;
1093                 if (x < MAXRESERVE) {
1094                         struct resource *res = reserve + x;
1095                         res->name = "reserved";
1096                         res->start = io_start;
1097                         res->end = io_start + io_num - 1;
1098                         res->flags = IORESOURCE_BUSY;
1099                         res->child = NULL;
1100                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1101                                 reserved = x+1;
1102                 }
1103         }
1104         return 1;
1105 }
1106
1107 __setup("reserve=", reserve_setup);
1108
1109 /*
1110  * Check if the requested addr and size spans more than any slot in the
1111  * iomem resource tree.
1112  */
1113 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1114 {
1115         struct resource *p = &iomem_resource;
1116         int err = 0;
1117         loff_t l;
1118
1119         read_lock(&resource_lock);
1120         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1121                 /*
1122                  * We can probably skip the resources without
1123                  * IORESOURCE_IO attribute?
1124                  */
1125                 if (p->start >= addr + size)
1126                         continue;
1127                 if (p->end < addr)
1128                         continue;
1129                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1130                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1131                         continue;
1132                 /*
1133                  * if a resource is "BUSY", it's not a hardware resource
1134                  * but a driver mapping of such a resource; we don't want
1135                  * to warn for those; some drivers legitimately map only
1136                  * partial hardware resources. (example: vesafb)
1137                  */
1138                 if (p->flags & IORESOURCE_BUSY)
1139                         continue;
1140
1141                 printk(KERN_WARNING "resource map sanity check conflict: "
1142                        "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
1143                        (unsigned long long)addr,
1144                        (unsigned long long)(addr + size - 1),
1145                        (unsigned long long)p->start,
1146                        (unsigned long long)p->end,
1147                        p->name);
1148                 err = -1;
1149                 break;
1150         }
1151         read_unlock(&resource_lock);
1152
1153         return err;
1154 }
1155
1156 #ifdef CONFIG_STRICT_DEVMEM
1157 static int strict_iomem_checks = 1;
1158 #else
1159 static int strict_iomem_checks;
1160 #endif
1161
1162 /*
1163  * check if an address is reserved in the iomem resource tree
1164  * returns 1 if reserved, 0 if not reserved.
1165  */
1166 int iomem_is_exclusive(u64 addr)
1167 {
1168         struct resource *p = &iomem_resource;
1169         int err = 0;
1170         loff_t l;
1171         int size = PAGE_SIZE;
1172
1173         if (!strict_iomem_checks)
1174                 return 0;
1175
1176         addr = addr & PAGE_MASK;
1177
1178         read_lock(&resource_lock);
1179         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1180                 /*
1181                  * We can probably skip the resources without
1182                  * IORESOURCE_IO attribute?
1183                  */
1184                 if (p->start >= addr + size)
1185                         break;
1186                 if (p->end < addr)
1187                         continue;
1188                 if (p->flags & IORESOURCE_BUSY &&
1189                      p->flags & IORESOURCE_EXCLUSIVE) {
1190                         err = 1;
1191                         break;
1192                 }
1193         }
1194         read_unlock(&resource_lock);
1195
1196         return err;
1197 }
1198
1199 static int __init strict_iomem(char *str)
1200 {
1201         if (strstr(str, "relaxed"))
1202                 strict_iomem_checks = 0;
1203         if (strstr(str, "strict"))
1204                 strict_iomem_checks = 1;
1205         return 1;
1206 }
1207
1208 __setup("iomem=", strict_iomem);