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 <linux/mm.h>
  25 #include <linux/resource_ext.h>
  26 #include <asm/io.h>
  27
  28
  29 struct resource ioport_resource = {
  30         .name   = "PCI IO",
  31         .start  = 0,
  32         .end    = IO_SPACE_LIMIT,
  33         .flags  = IORESOURCE_IO,
  34 };
  35 EXPORT_SYMBOL(ioport_resource);
  36
  37 struct resource iomem_resource = {
  38         .name   = "PCI mem",
  39         .start  = 0,
  40         .end    = -1,
  41         .flags  = IORESOURCE_MEM,
  42 };
  43 EXPORT_SYMBOL(iomem_resource);
  44
  45 /* constraints to be met while allocating resources */
  46 struct resource_constraint {
  47         resource_size_t min, max, align;
  48         resource_size_t (*alignf)(void *, const struct resource *,
  49                         resource_size_t, resource_size_t);
  50         void *alignf_data;
  51 };
  52
  53 static DEFINE_RWLOCK(resource_lock);
  54
  55 /*
  56  * For memory hotplug, there is no way to free resource entries allocated
  57  * by boot mem after the system is up. So for reusing the resource entry
  58  * we need to remember the resource.
  59  */
  60 static struct resource *bootmem_resource_free;
  61 static DEFINE_SPINLOCK(bootmem_resource_lock);
  62
  63 static struct resource *next_resource(struct resource *p, bool sibling_only)
  64 {
  65         /* Caller wants to traverse through siblings only */
  66         if (sibling_only)
  67                 return p->sibling;
  68
  69         if (p->child)
  70                 return p->child;
  71         while (!p->sibling && p->parent)
  72                 p = p->parent;
  73         return p->sibling;
  74 }
  75
  76 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  77 {
  78         struct resource *p = v;
  79         (*pos)++;
  80         return (void *)next_resource(p, false);
  81 }
  82
  83 #ifdef CONFIG_PROC_FS
  84
  85 enum { MAX_IORES_LEVEL = 5 };
  86
  87 static void *r_start(struct seq_file *m, loff_t *pos)
  88         __acquires(resource_lock)
  89 {
  90         struct resource *p = m->private;
  91         loff_t l = 0;
  92         read_lock(&resource_lock);
  93         for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  94                 ;
  95         return p;
  96 }
  97
  98 static void r_stop(struct seq_file *m, void *v)
  99         __releases(resource_lock)
 100 {
 101         read_unlock(&resource_lock);
 102 }
 103
 104 static int r_show(struct seq_file *m, void *v)
 105 {
 106         struct resource *root = m->private;
 107         struct resource *r = v, *p;
 108         int width = root->end < 0x10000 ? 4 : 8;
 109         int depth;
 110
 111         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
 112                 if (p->parent == root)
 113                         break;
 114         seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
 115                         depth * 2, "",
 116                         width, (unsigned long long) r->start,
 117                         width, (unsigned long long) r->end,
 118                         r->name ? r->name : "<BAD>");
 119         return 0;
 120 }
 121
 122 static const struct seq_operations resource_op = {
 123         .start  = r_start,
 124         .next   = r_next,
 125         .stop   = r_stop,
 126         .show   = r_show,
 127 };
 128
 129 static int ioports_open(struct inode *inode, struct file *file)
 130 {
 131         int res = seq_open(file, &resource_op);
 132         if (!res) {
 133                 struct seq_file *m = file->private_data;
 134                 m->private = &ioport_resource;
 135         }
 136         return res;
 137 }
 138
 139 static int iomem_open(struct inode *inode, struct file *file)
 140 {
 141         int res = seq_open(file, &resource_op);
 142         if (!res) {
 143                 struct seq_file *m = file->private_data;
 144                 m->private = &iomem_resource;
 145         }
 146         return res;
 147 }
 148
 149 static const struct file_operations proc_ioports_operations = {
 150         .open           = ioports_open,
 151         .read           = seq_read,
 152         .llseek         = seq_lseek,
 153         .release        = seq_release,
 154 };
 155
 156 static const struct file_operations proc_iomem_operations = {
 157         .open           = iomem_open,
 158         .read           = seq_read,
 159         .llseek         = seq_lseek,
 160         .release        = seq_release,
 161 };
 162
 163 static int __init ioresources_init(void)
 164 {
 165         proc_create("ioports", 0, NULL, &proc_ioports_operations);
 166         proc_create("iomem", 0, NULL, &proc_iomem_operations);
 167         return 0;
 168 }
 169 __initcall(ioresources_init);
 170
 171 #endif /* CONFIG_PROC_FS */
 172
 173 static void free_resource(struct resource *res)
 174 {
 175         if (!res)
 176                 return;
 177
 178         if (!PageSlab(virt_to_head_page(res))) {
 179                 spin_lock(&bootmem_resource_lock);
 180                 res->sibling = bootmem_resource_free;
 181                 bootmem_resource_free = res;
 182                 spin_unlock(&bootmem_resource_lock);
 183         } else {
 184                 kfree(res);
 185         }
 186 }
 187
 188 static struct resource *alloc_resource(gfp_t flags)
 189 {
 190         struct resource *res = NULL;
 191
 192         spin_lock(&bootmem_resource_lock);
 193         if (bootmem_resource_free) {
 194                 res = bootmem_resource_free;
 195                 bootmem_resource_free = res->sibling;
 196         }
 197         spin_unlock(&bootmem_resource_lock);
 198
 199         if (res)
 200                 memset(res, 0, sizeof(struct resource));
 201         else
 202                 res = kzalloc(sizeof(struct resource), flags);
 203
 204         return res;
 205 }
 206
 207 /* Return the conflict entry if you can't request it */
 208 static struct resource * __request_resource(struct resource *root, struct resource *new)
 209 {
 210         resource_size_t start = new->start;
 211         resource_size_t end = new->end;
 212         struct resource *tmp, **p;
 213
 214         if (end < start)
 215                 return root;
 216         if (start < root->start)
 217                 return root;
 218         if (end > root->end)
 219                 return root;
 220         p = &root->child;
 221         for (;;) {
 222                 tmp = *p;
 223                 if (!tmp || tmp->start > end) {
 224                         new->sibling = tmp;
 225                         *p = new;
 226                         new->parent = root;
 227                         return NULL;
 228                 }
 229                 p = &tmp->sibling;
 230                 if (tmp->end < start)
 231                         continue;
 232                 return tmp;
 233         }
 234 }
 235
 236 static int __release_resource(struct resource *old)
 237 {
 238         struct resource *tmp, **p;
 239
 240         p = &old->parent->child;
 241         for (;;) {
 242                 tmp = *p;
 243                 if (!tmp)
 244                         break;
 245                 if (tmp == old) {
 246                         *p = tmp->sibling;
 247                         old->parent = NULL;
 248                         return 0;
 249                 }
 250                 p = &tmp->sibling;
 251         }
 252         return -EINVAL;
 253 }
 254
 255 static void __release_child_resources(struct resource *r)
 256 {
 257         struct resource *tmp, *p;
 258         resource_size_t size;
 259
 260         p = r->child;
 261         r->child = NULL;
 262         while (p) {
 263                 tmp = p;
 264                 p = p->sibling;
 265
 266                 tmp->parent = NULL;
 267                 tmp->sibling = NULL;
 268                 __release_child_resources(tmp);
 269
 270                 printk(KERN_DEBUG "release child resource %pR\n", tmp);
 271                 /* need to restore size, and keep flags */
 272                 size = resource_size(tmp);
 273                 tmp->start = 0;
 274                 tmp->end = size - 1;
 275         }
 276 }
 277
 278 void release_child_resources(struct resource *r)
 279 {
 280         write_lock(&resource_lock);
 281         __release_child_resources(r);
 282         write_unlock(&resource_lock);
 283 }
 284
 285 /**
 286  * request_resource_conflict - request and reserve an I/O or memory resource
 287  * @root: root resource descriptor
 288  * @new: resource descriptor desired by caller
 289  *
 290  * Returns 0 for success, conflict resource on error.
 291  */
 292 struct resource *request_resource_conflict(struct resource *root, struct resource *new)
 293 {
 294         struct resource *conflict;
 295
 296         write_lock(&resource_lock);
 297         conflict = __request_resource(root, new);
 298         write_unlock(&resource_lock);
 299         return conflict;
 300 }
 301
 302 /**
 303  * request_resource - request and reserve an I/O or memory resource
 304  * @root: root resource descriptor
 305  * @new: resource descriptor desired by caller
 306  *
 307  * Returns 0 for success, negative error code on error.
 308  */
 309 int request_resource(struct resource *root, struct resource *new)
 310 {
 311         struct resource *conflict;
 312
 313         conflict = request_resource_conflict(root, new);
 314         return conflict ? -EBUSY : 0;
 315 }
 316
 317 EXPORT_SYMBOL(request_resource);
 318
 319 /**
 320  * release_resource - release a previously reserved resource
 321  * @old: resource pointer
 322  */
 323 int release_resource(struct resource *old)
 324 {
 325         int retval;
 326
 327         write_lock(&resource_lock);
 328         retval = __release_resource(old);
 329         write_unlock(&resource_lock);
 330         return retval;
 331 }
 332
 333 EXPORT_SYMBOL(release_resource);
 334
 335 /*
 336  * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
 337  * the caller must specify res->start, res->end, res->flags and "name".
 338  * If found, returns 0, res is overwritten, if not found, returns -1.
 339  * This walks through whole tree and not just first level children
 340  * until and unless first_level_children_only is true.
 341  */
 342 static int find_next_iomem_res(struct resource *res, char *name,
 343                                bool first_level_children_only)
 344 {
 345         resource_size_t start, end;
 346         struct resource *p;
 347         bool sibling_only = false;
 348
 349         BUG_ON(!res);
 350
 351         start = res->start;
 352         end = res->end;
 353         BUG_ON(start >= end);
 354
 355         if (first_level_children_only)
 356                 sibling_only = true;
 357
 358         read_lock(&resource_lock);
 359
 360         for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
 361                 if (p->flags != res->flags)
 362                         continue;
 363                 if (name && strcmp(p->name, name))
 364                         continue;
 365                 if (p->start > end) {
 366                         p = NULL;
 367                         break;
 368                 }
 369                 if ((p->end >= start) && (p->start < end))
 370                         break;
 371         }
 372
 373         read_unlock(&resource_lock);
 374         if (!p)
 375                 return -1;
 376         /* copy data */
 377         if (res->start < p->start)
 378                 res->start = p->start;
 379         if (res->end > p->end)
 380                 res->end = p->end;
 381         return 0;
 382 }
 383
 384 /*
 385  * Walks through iomem resources and calls func() with matching resource
 386  * ranges. This walks through whole tree and not just first level children.
 387  * All the memory ranges which overlap start,end and also match flags and
 388  * name are valid candidates.
 389  *
 390  * @name: name of resource
 391  * @flags: resource flags
 392  * @start: start addr
 393  * @end: end addr
 394  */
 395 int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
 396                 void *arg, int (*func)(u64, u64, void *))
 397 {
 398         struct resource res;
 399         u64 orig_end;
 400         int ret = -1;
 401
 402         res.start = start;
 403         res.end = end;
 404         res.flags = flags;
 405         orig_end = res.end;
 406         while ((res.start < res.end) &&
 407                 (!find_next_iomem_res(&res, name, false))) {
 408                 ret = (*func)(res.start, res.end, arg);
 409                 if (ret)
 410                         break;
 411                 res.start = res.end + 1;
 412                 res.end = orig_end;
 413         }
 414         return ret;
 415 }
 416
 417 /*
 418  * This function calls callback against all memory range of "System RAM"
 419  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 420  * Now, this function is only for "System RAM". This function deals with
 421  * full ranges and not pfn. If resources are not pfn aligned, dealing
 422  * with pfn can truncate ranges.
 423  */
 424 int walk_system_ram_res(u64 start, u64 end, void *arg,
 425                                 int (*func)(u64, u64, void *))
 426 {
 427         struct resource res;
 428         u64 orig_end;
 429         int ret = -1;
 430
 431         res.start = start;
 432         res.end = end;
 433         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 434         orig_end = res.end;
 435         while ((res.start < res.end) &&
 436                 (!find_next_iomem_res(&res, "System RAM", true))) {
 437                 ret = (*func)(res.start, res.end, arg);
 438                 if (ret)
 439                         break;
 440                 res.start = res.end + 1;
 441                 res.end = orig_end;
 442         }
 443         return ret;
 444 }
 445
 446 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 447
 448 /*
 449  * This function calls callback against all memory range of "System RAM"
 450  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 451  * Now, this function is only for "System RAM".
 452  */
 453 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 454                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 455 {
 456         struct resource res;
 457         unsigned long pfn, end_pfn;
 458         u64 orig_end;
 459         int ret = -1;
 460
 461         res.start = (u64) start_pfn << PAGE_SHIFT;
 462         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 463         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 464         orig_end = res.end;
 465         while ((res.start < res.end) &&
 466                 (find_next_iomem_res(&res, "System RAM", true) >= 0)) {
 467                 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 468                 end_pfn = (res.end + 1) >> PAGE_SHIFT;
 469                 if (end_pfn > pfn)
 470                         ret = (*func)(pfn, end_pfn - pfn, arg);
 471                 if (ret)
 472                         break;
 473                 res.start = res.end + 1;
 474                 res.end = orig_end;
 475         }
 476         return ret;
 477 }
 478
 479 #endif
 480
 481 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 482 {
 483         return 1;
 484 }
 485 /*
 486  * This generic page_is_ram() returns true if specified address is
 487  * registered as "System RAM" in iomem_resource list.
 488  */
 489 int __weak page_is_ram(unsigned long pfn)
 490 {
 491         return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 492 }
 493 EXPORT_SYMBOL_GPL(page_is_ram);
 494
 495 /*
 496  * Search for a resouce entry that fully contains the specified region.
 497  * If found, return 1 if it is RAM, 0 if not.
 498  * If not found, or region is not fully contained, return -1
 499  *
 500  * Used by the ioremap functions to ensure the user is not remapping RAM and is
 501  * a vast speed up over walking through the resource table page by page.
 502  */
 503 int region_is_ram(resource_size_t start, unsigned long size)
 504 {
 505         struct resource *p;
 506         resource_size_t end = start + size - 1;
 507         unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 508         const char *name = "System RAM";
 509         int ret = -1;
 510
 511         read_lock(&resource_lock);
 512         for (p = iomem_resource.child; p ; p = p->sibling) {
 513                 if (p->end < start)
 514                         continue;
 515
 516                 if (p->start <= start && end <= p->end) {
 517                         /* resource fully contains region */
 518                         if ((p->flags != flags) || strcmp(p->name, name))
 519                                 ret = 0;
 520                         else
 521                                 ret = 1;
 522                         break;
 523                 }
 524                 if (end < p->start)
 525                         break;  /* not found */
 526         }
 527         read_unlock(&resource_lock);
 528         return ret;
 529 }
 530
 531 void __weak arch_remove_reservations(struct resource *avail)
 532 {
 533 }
 534
 535 static resource_size_t simple_align_resource(void *data,
 536                                              const struct resource *avail,
 537                                              resource_size_t size,
 538                                              resource_size_t align)
 539 {
 540         return avail->start;
 541 }
 542
 543 static void resource_clip(struct resource *res, resource_size_t min,
 544                           resource_size_t max)
 545 {
 546         if (res->start < min)
 547                 res->start = min;
 548         if (res->end > max)
 549                 res->end = max;
 550 }
 551
 552 /*
 553  * Find empty slot in the resource tree with the given range and
 554  * alignment constraints
 555  */
 556 static int __find_resource(struct resource *root, struct resource *old,
 557                          struct resource *new,
 558                          resource_size_t  size,
 559                          struct resource_constraint *constraint)
 560 {
 561         struct resource *this = root->child;
 562         struct resource tmp = *new, avail, alloc;
 563
 564         tmp.start = root->start;
 565         /*
 566          * Skip past an allocated resource that starts at 0, since the assignment
 567          * of this->start - 1 to tmp->end below would cause an underflow.
 568          */
 569         if (this && this->start == root->start) {
 570                 tmp.start = (this == old) ? old->start : this->end + 1;
 571                 this = this->sibling;
 572         }
 573         for(;;) {
 574                 if (this)
 575                         tmp.end = (this == old) ?  this->end : this->start - 1;
 576                 else
 577                         tmp.end = root->end;
 578
 579                 if (tmp.end < tmp.start)
 580                         goto next;
 581
 582                 resource_clip(&tmp, constraint->min, constraint->max);
 583                 arch_remove_reservations(&tmp);
 584
 585                 /* Check for overflow after ALIGN() */
 586                 avail.start = ALIGN(tmp.start, constraint->align);
 587                 avail.end = tmp.end;
 588                 avail.flags = new->flags & ~IORESOURCE_UNSET;
 589                 if (avail.start >= tmp.start) {
 590                         alloc.flags = avail.flags;
 591                         alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 592                                         size, constraint->align);
 593                         alloc.end = alloc.start + size - 1;
 594                         if (resource_contains(&avail, &alloc)) {
 595                                 new->start = alloc.start;
 596                                 new->end = alloc.end;
 597                                 return 0;
 598                         }
 599                 }
 600
 601 next:           if (!this || this->end == root->end)
 602                         break;
 603
 604                 if (this != old)
 605                         tmp.start = this->end + 1;
 606                 this = this->sibling;
 607         }
 608         return -EBUSY;
 609 }
 610
 611 /*
 612  * Find empty slot in the resource tree given range and alignment.
 613  */
 614 static int find_resource(struct resource *root, struct resource *new,
 615                         resource_size_t size,
 616                         struct resource_constraint  *constraint)
 617 {
 618         return  __find_resource(root, NULL, new, size, constraint);
 619 }
 620
 621 /**
 622  * reallocate_resource - allocate a slot in the resource tree given range & alignment.
 623  *      The resource will be relocated if the new size cannot be reallocated in the
 624  *      current location.
 625  *
 626  * @root: root resource descriptor
 627  * @old:  resource descriptor desired by caller
 628  * @newsize: new size of the resource descriptor
 629  * @constraint: the size and alignment constraints to be met.
 630  */
 631 static int reallocate_resource(struct resource *root, struct resource *old,
 632                         resource_size_t newsize,
 633                         struct resource_constraint  *constraint)
 634 {
 635         int err=0;
 636         struct resource new = *old;
 637         struct resource *conflict;
 638
 639         write_lock(&resource_lock);
 640
 641         if ((err = __find_resource(root, old, &new, newsize, constraint)))
 642                 goto out;
 643
 644         if (resource_contains(&new, old)) {
 645                 old->start = new.start;
 646                 old->end = new.end;
 647                 goto out;
 648         }
 649
 650         if (old->child) {
 651                 err = -EBUSY;
 652                 goto out;
 653         }
 654
 655         if (resource_contains(old, &new)) {
 656                 old->start = new.start;
 657                 old->end = new.end;
 658         } else {
 659                 __release_resource(old);
 660                 *old = new;
 661                 conflict = __request_resource(root, old);
 662                 BUG_ON(conflict);
 663         }
 664 out:
 665         write_unlock(&resource_lock);
 666         return err;
 667 }
 668
 669
 670 /**
 671  * allocate_resource - allocate empty slot in the resource tree given range & alignment.
 672  *      The resource will be reallocated with a new size if it was already allocated
 673  * @root: root resource descriptor
 674  * @new: resource descriptor desired by caller
 675  * @size: requested resource region size
 676  * @min: minimum boundary to allocate
 677  * @max: maximum boundary to allocate
 678  * @align: alignment requested, in bytes
 679  * @alignf: alignment function, optional, called if not NULL
 680  * @alignf_data: arbitrary data to pass to the @alignf function
 681  */
 682 int allocate_resource(struct resource *root, struct resource *new,
 683                       resource_size_t size, resource_size_t min,
 684                       resource_size_t max, resource_size_t align,
 685                       resource_size_t (*alignf)(void *,
 686                                                 const struct resource *,
 687                                                 resource_size_t,
 688                                                 resource_size_t),
 689                       void *alignf_data)
 690 {
 691         int err;
 692         struct resource_constraint constraint;
 693
 694         if (!alignf)
 695                 alignf = simple_align_resource;
 696
 697         constraint.min = min;
 698         constraint.max = max;
 699         constraint.align = align;
 700         constraint.alignf = alignf;
 701         constraint.alignf_data = alignf_data;
 702
 703         if ( new->parent ) {
 704                 /* resource is already allocated, try reallocating with
 705                    the new constraints */
 706                 return reallocate_resource(root, new, size, &constraint);
 707         }
 708
 709         write_lock(&resource_lock);
 710         err = find_resource(root, new, size, &constraint);
 711         if (err >= 0 && __request_resource(root, new))
 712                 err = -EBUSY;
 713         write_unlock(&resource_lock);
 714         return err;
 715 }
 716
 717 EXPORT_SYMBOL(allocate_resource);
 718
 719 /**
 720  * lookup_resource - find an existing resource by a resource start address
 721  * @root: root resource descriptor
 722  * @start: resource start address
 723  *
 724  * Returns a pointer to the resource if found, NULL otherwise
 725  */
 726 struct resource *lookup_resource(struct resource *root, resource_size_t start)
 727 {
 728         struct resource *res;
 729
 730         read_lock(&resource_lock);
 731         for (res = root->child; res; res = res->sibling) {
 732                 if (res->start == start)
 733                         break;
 734         }
 735         read_unlock(&resource_lock);
 736
 737         return res;
 738 }
 739
 740 /*
 741  * Insert a resource into the resource tree. If successful, return NULL,
 742  * otherwise return the conflicting resource (compare to __request_resource())
 743  */
 744 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 745 {
 746         struct resource *first, *next;
 747
 748         for (;; parent = first) {
 749                 first = __request_resource(parent, new);
 750                 if (!first)
 751                         return first;
 752
 753                 if (first == parent)
 754                         return first;
 755                 if (WARN_ON(first == new))      /* duplicated insertion */
 756                         return first;
 757
 758                 if ((first->start > new->start) || (first->end < new->end))
 759                         break;
 760                 if ((first->start == new->start) && (first->end == new->end))
 761                         break;
 762         }
 763
 764         for (next = first; ; next = next->sibling) {
 765                 /* Partial overlap? Bad, and unfixable */
 766                 if (next->start < new->start || next->end > new->end)
 767                         return next;
 768                 if (!next->sibling)
 769                         break;
 770                 if (next->sibling->start > new->end)
 771                         break;
 772         }
 773
 774         new->parent = parent;
 775         new->sibling = next->sibling;
 776         new->child = first;
 777
 778         next->sibling = NULL;
 779         for (next = first; next; next = next->sibling)
 780                 next->parent = new;
 781
 782         if (parent->child == first) {
 783                 parent->child = new;
 784         } else {
 785                 next = parent->child;
 786                 while (next->sibling != first)
 787                         next = next->sibling;
 788                 next->sibling = new;
 789         }
 790         return NULL;
 791 }
 792
 793 /**
 794  * insert_resource_conflict - Inserts resource in the resource tree
 795  * @parent: parent of the new resource
 796  * @new: new resource to insert
 797  *
 798  * Returns 0 on success, conflict resource if the resource can't be inserted.
 799  *
 800  * This function is equivalent to request_resource_conflict when no conflict
 801  * happens. If a conflict happens, and the conflicting resources
 802  * entirely fit within the range of the new resource, then the new
 803  * resource is inserted and the conflicting resources become children of
 804  * the new resource.
 805  */
 806 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 807 {
 808         struct resource *conflict;
 809
 810         write_lock(&resource_lock);
 811         conflict = __insert_resource(parent, new);
 812         write_unlock(&resource_lock);
 813         return conflict;
 814 }
 815
 816 /**
 817  * insert_resource - Inserts a resource in the resource tree
 818  * @parent: parent of the new resource
 819  * @new: new resource to insert
 820  *
 821  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 822  */
 823 int insert_resource(struct resource *parent, struct resource *new)
 824 {
 825         struct resource *conflict;
 826
 827         conflict = insert_resource_conflict(parent, new);
 828         return conflict ? -EBUSY : 0;
 829 }
 830
 831 /**
 832  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 833  * @root: root resource descriptor
 834  * @new: new resource to insert
 835  *
 836  * Insert a resource into the resource tree, possibly expanding it in order
 837  * to make it encompass any conflicting resources.
 838  */
 839 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 840 {
 841         if (new->parent)
 842                 return;
 843
 844         write_lock(&resource_lock);
 845         for (;;) {
 846                 struct resource *conflict;
 847
 848                 conflict = __insert_resource(root, new);
 849                 if (!conflict)
 850                         break;
 851                 if (conflict == root)
 852                         break;
 853
 854                 /* Ok, expand resource to cover the conflict, then try again .. */
 855                 if (conflict->start < new->start)
 856                         new->start = conflict->start;
 857                 if (conflict->end > new->end)
 858                         new->end = conflict->end;
 859
 860                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 861         }
 862         write_unlock(&resource_lock);
 863 }
 864
 865 static int __adjust_resource(struct resource *res, resource_size_t start,
 866                                 resource_size_t size)
 867 {
 868         struct resource *tmp, *parent = res->parent;
 869         resource_size_t end = start + size - 1;
 870         int result = -EBUSY;
 871
 872         if (!parent)
 873                 goto skip;
 874
 875         if ((start < parent->start) || (end > parent->end))
 876                 goto out;
 877
 878         if (res->sibling && (res->sibling->start <= end))
 879                 goto out;
 880
 881         tmp = parent->child;
 882         if (tmp != res) {
 883                 while (tmp->sibling != res)
 884                         tmp = tmp->sibling;
 885                 if (start <= tmp->end)
 886                         goto out;
 887         }
 888
 889 skip:
 890         for (tmp = res->child; tmp; tmp = tmp->sibling)
 891                 if ((tmp->start < start) || (tmp->end > end))
 892                         goto out;
 893
 894         res->start = start;
 895         res->end = end;
 896         result = 0;
 897
 898  out:
 899         return result;
 900 }
 901
 902 /**
 903  * adjust_resource - modify a resource's start and size
 904  * @res: resource to modify
 905  * @start: new start value
 906  * @size: new size
 907  *
 908  * Given an existing resource, change its start and size to match the
 909  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 910  * Existing children of the resource are assumed to be immutable.
 911  */
 912 int adjust_resource(struct resource *res, resource_size_t start,
 913                         resource_size_t size)
 914 {
 915         int result;
 916
 917         write_lock(&resource_lock);
 918         result = __adjust_resource(res, start, size);
 919         write_unlock(&resource_lock);
 920         return result;
 921 }
 922 EXPORT_SYMBOL(adjust_resource);
 923
 924 static void __init __reserve_region_with_split(struct resource *root,
 925                 resource_size_t start, resource_size_t end,
 926                 const char *name)
 927 {
 928         struct resource *parent = root;
 929         struct resource *conflict;
 930         struct resource *res = alloc_resource(GFP_ATOMIC);
 931         struct resource *next_res = NULL;
 932
 933         if (!res)
 934                 return;
 935
 936         res->name = name;
 937         res->start = start;
 938         res->end = end;
 939         res->flags = IORESOURCE_BUSY;
 940
 941         while (1) {
 942
 943                 conflict = __request_resource(parent, res);
 944                 if (!conflict) {
 945                         if (!next_res)
 946                                 break;
 947                         res = next_res;
 948                         next_res = NULL;
 949                         continue;
 950                 }
 951
 952                 /* conflict covered whole area */
 953                 if (conflict->start <= res->start &&
 954                                 conflict->end >= res->end) {
 955                         free_resource(res);
 956                         WARN_ON(next_res);
 957                         break;
 958                 }
 959
 960                 /* failed, split and try again */
 961                 if (conflict->start > res->start) {
 962                         end = res->end;
 963                         res->end = conflict->start - 1;
 964                         if (conflict->end < end) {
 965                                 next_res = alloc_resource(GFP_ATOMIC);
 966                                 if (!next_res) {
 967                                         free_resource(res);
 968                                         break;
 969                                 }
 970                                 next_res->name = name;
 971                                 next_res->start = conflict->end + 1;
 972                                 next_res->end = end;
 973                                 next_res->flags = IORESOURCE_BUSY;
 974                         }
 975                 } else {
 976                         res->start = conflict->end + 1;
 977                 }
 978         }
 979
 980 }
 981
 982 void __init reserve_region_with_split(struct resource *root,
 983                 resource_size_t start, resource_size_t end,
 984                 const char *name)
 985 {
 986         int abort = 0;
 987
 988         write_lock(&resource_lock);
 989         if (root->start > start || root->end < end) {
 990                 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
 991                        (unsigned long long)start, (unsigned long long)end,
 992                        root);
 993                 if (start > root->end || end < root->start)
 994                         abort = 1;
 995                 else {
 996                         if (end > root->end)
 997                                 end = root->end;
 998                         if (start < root->start)
 999                                 start = root->start;
1000                         pr_err("fixing request to [0x%llx-0x%llx]\n",
1001                                (unsigned long long)start,
1002                                (unsigned long long)end);
1003                 }
1004                 dump_stack();
1005         }
1006         if (!abort)
1007                 __reserve_region_with_split(root, start, end, name);
1008         write_unlock(&resource_lock);
1009 }
1010
1011 /**
1012  * resource_alignment - calculate resource's alignment
1013  * @res: resource pointer
1014  *
1015  * Returns alignment on success, 0 (invalid alignment) on failure.
1016  */
1017 resource_size_t resource_alignment(struct resource *res)
1018 {
1019         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1020         case IORESOURCE_SIZEALIGN:
1021                 return resource_size(res);
1022         case IORESOURCE_STARTALIGN:
1023                 return res->start;
1024         default:
1025                 return 0;
1026         }
1027 }
1028
1029 /*
1030  * This is compatibility stuff for IO resources.
1031  *
1032  * Note how this, unlike the above, knows about
1033  * the IO flag meanings (busy etc).
1034  *
1035  * request_region creates a new busy region.
1036  *
1037  * release_region releases a matching busy region.
1038  */
1039
1040 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1041
1042 /**
1043  * __request_region - create a new busy resource region
1044  * @parent: parent resource descriptor
1045  * @start: resource start address
1046  * @n: resource region size
1047  * @name: reserving caller's ID string
1048  * @flags: IO resource flags
1049  */
1050 struct resource * __request_region(struct resource *parent,
1051                                    resource_size_t start, resource_size_t n,
1052                                    const char *name, int flags)
1053 {
1054         DECLARE_WAITQUEUE(wait, current);
1055         struct resource *res = alloc_resource(GFP_KERNEL);
1056
1057         if (!res)
1058                 return NULL;
1059
1060         res->name = name;
1061         res->start = start;
1062         res->end = start + n - 1;
1063         res->flags = resource_type(parent);
1064         res->flags |= IORESOURCE_BUSY | flags;
1065
1066         write_lock(&resource_lock);
1067
1068         for (;;) {
1069                 struct resource *conflict;
1070
1071                 conflict = __request_resource(parent, res);
1072                 if (!conflict)
1073                         break;
1074                 if (conflict != parent) {
1075                         parent = conflict;
1076                         if (!(conflict->flags & IORESOURCE_BUSY))
1077                                 continue;
1078                 }
1079                 if (conflict->flags & flags & IORESOURCE_MUXED) {
1080                         add_wait_queue(&muxed_resource_wait, &wait);
1081                         write_unlock(&resource_lock);
1082                         set_current_state(TASK_UNINTERRUPTIBLE);
1083                         schedule();
1084                         remove_wait_queue(&muxed_resource_wait, &wait);
1085                         write_lock(&resource_lock);
1086                         continue;
1087                 }
1088                 /* Uhhuh, that didn't work out.. */
1089                 free_resource(res);
1090                 res = NULL;
1091                 break;
1092         }
1093         write_unlock(&resource_lock);
1094         return res;
1095 }
1096 EXPORT_SYMBOL(__request_region);
1097
1098 /**
1099  * __release_region - release a previously reserved resource region
1100  * @parent: parent resource descriptor
1101  * @start: resource start address
1102  * @n: resource region size
1103  *
1104  * The described resource region must match a currently busy region.
1105  */
1106 void __release_region(struct resource *parent, resource_size_t start,
1107                         resource_size_t n)
1108 {
1109         struct resource **p;
1110         resource_size_t end;
1111
1112         p = &parent->child;
1113         end = start + n - 1;
1114
1115         write_lock(&resource_lock);
1116
1117         for (;;) {
1118                 struct resource *res = *p;
1119
1120                 if (!res)
1121                         break;
1122                 if (res->start <= start && res->end >= end) {
1123                         if (!(res->flags & IORESOURCE_BUSY)) {
1124                                 p = &res->child;
1125                                 continue;
1126                         }
1127                         if (res->start != start || res->end != end)
1128                                 break;
1129                         *p = res->sibling;
1130                         write_unlock(&resource_lock);
1131                         if (res->flags & IORESOURCE_MUXED)
1132                                 wake_up(&muxed_resource_wait);
1133                         free_resource(res);
1134                         return;
1135                 }
1136                 p = &res->sibling;
1137         }
1138
1139         write_unlock(&resource_lock);
1140
1141         printk(KERN_WARNING "Trying to free nonexistent resource "
1142                 "<%016llx-%016llx>\n", (unsigned long long)start,
1143                 (unsigned long long)end);
1144 }
1145 EXPORT_SYMBOL(__release_region);
1146
1147 #ifdef CONFIG_MEMORY_HOTREMOVE
1148 /**
1149  * release_mem_region_adjustable - release a previously reserved memory region
1150  * @parent: parent resource descriptor
1151  * @start: resource start address
1152  * @size: resource region size
1153  *
1154  * This interface is intended for memory hot-delete.  The requested region
1155  * is released from a currently busy memory resource.  The requested region
1156  * must either match exactly or fit into a single busy resource entry.  In
1157  * the latter case, the remaining resource is adjusted accordingly.
1158  * Existing children of the busy memory resource must be immutable in the
1159  * request.
1160  *
1161  * Note:
1162  * - Additional release conditions, such as overlapping region, can be
1163  *   supported after they are confirmed as valid cases.
1164  * - When a busy memory resource gets split into two entries, the code
1165  *   assumes that all children remain in the lower address entry for
1166  *   simplicity.  Enhance this logic when necessary.
1167  */
1168 int release_mem_region_adjustable(struct resource *parent,
1169                         resource_size_t start, resource_size_t size)
1170 {
1171         struct resource **p;
1172         struct resource *res;
1173         struct resource *new_res;
1174         resource_size_t end;
1175         int ret = -EINVAL;
1176
1177         end = start + size - 1;
1178         if ((start < parent->start) || (end > parent->end))
1179                 return ret;
1180
1181         /* The alloc_resource() result gets checked later */
1182         new_res = alloc_resource(GFP_KERNEL);
1183
1184         p = &parent->child;
1185         write_lock(&resource_lock);
1186
1187         while ((res = *p)) {
1188                 if (res->start >= end)
1189                         break;
1190
1191                 /* look for the next resource if it does not fit into */
1192                 if (res->start > start || res->end < end) {
1193                         p = &res->sibling;
1194                         continue;
1195                 }
1196
1197                 if (!(res->flags & IORESOURCE_MEM))
1198                         break;
1199
1200                 if (!(res->flags & IORESOURCE_BUSY)) {
1201                         p = &res->child;
1202                         continue;
1203                 }
1204
1205                 /* found the target resource; let's adjust accordingly */
1206                 if (res->start == start && res->end == end) {
1207                         /* free the whole entry */
1208                         *p = res->sibling;
1209                         free_resource(res);
1210                         ret = 0;
1211                 } else if (res->start == start && res->end != end) {
1212                         /* adjust the start */
1213                         ret = __adjust_resource(res, end + 1,
1214                                                 res->end - end);
1215                 } else if (res->start != start && res->end == end) {
1216                         /* adjust the end */
1217                         ret = __adjust_resource(res, res->start,
1218                                                 start - res->start);
1219                 } else {
1220                         /* split into two entries */
1221                         if (!new_res) {
1222                                 ret = -ENOMEM;
1223                                 break;
1224                         }
1225                         new_res->name = res->name;
1226                         new_res->start = end + 1;
1227                         new_res->end = res->end;
1228                         new_res->flags = res->flags;
1229                         new_res->parent = res->parent;
1230                         new_res->sibling = res->sibling;
1231                         new_res->child = NULL;
1232
1233                         ret = __adjust_resource(res, res->start,
1234                                                 start - res->start);
1235                         if (ret)
1236                                 break;
1237                         res->sibling = new_res;
1238                         new_res = NULL;
1239                 }
1240
1241                 break;
1242         }
1243
1244         write_unlock(&resource_lock);
1245         free_resource(new_res);
1246         return ret;
1247 }
1248 #endif  /* CONFIG_MEMORY_HOTREMOVE */
1249
1250 /*
1251  * Managed region resource
1252  */
1253 static void devm_resource_release(struct device *dev, void *ptr)
1254 {
1255         struct resource **r = ptr;
1256
1257         release_resource(*r);
1258 }
1259
1260 /**
1261  * devm_request_resource() - request and reserve an I/O or memory resource
1262  * @dev: device for which to request the resource
1263  * @root: root of the resource tree from which to request the resource
1264  * @new: descriptor of the resource to request
1265  *
1266  * This is a device-managed version of request_resource(). There is usually
1267  * no need to release resources requested by this function explicitly since
1268  * that will be taken care of when the device is unbound from its driver.
1269  * If for some reason the resource needs to be released explicitly, because
1270  * of ordering issues for example, drivers must call devm_release_resource()
1271  * rather than the regular release_resource().
1272  *
1273  * When a conflict is detected between any existing resources and the newly
1274  * requested resource, an error message will be printed.
1275  *
1276  * Returns 0 on success or a negative error code on failure.
1277  */
1278 int devm_request_resource(struct device *dev, struct resource *root,
1279                           struct resource *new)
1280 {
1281         struct resource *conflict, **ptr;
1282
1283         ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1284         if (!ptr)
1285                 return -ENOMEM;
1286
1287         *ptr = new;
1288
1289         conflict = request_resource_conflict(root, new);
1290         if (conflict) {
1291                 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1292                         new, conflict->name, conflict);
1293                 devres_free(ptr);
1294                 return -EBUSY;
1295         }
1296
1297         devres_add(dev, ptr);
1298         return 0;
1299 }
1300 EXPORT_SYMBOL(devm_request_resource);
1301
1302 static int devm_resource_match(struct device *dev, void *res, void *data)
1303 {
1304         struct resource **ptr = res;
1305
1306         return *ptr == data;
1307 }
1308
1309 /**
1310  * devm_release_resource() - release a previously requested resource
1311  * @dev: device for which to release the resource
1312  * @new: descriptor of the resource to release
1313  *
1314  * Releases a resource previously requested using devm_request_resource().
1315  */
1316 void devm_release_resource(struct device *dev, struct resource *new)
1317 {
1318         WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1319                                new));
1320 }
1321 EXPORT_SYMBOL(devm_release_resource);
1322
1323 struct region_devres {
1324         struct resource *parent;
1325         resource_size_t start;
1326         resource_size_t n;
1327 };
1328
1329 static void devm_region_release(struct device *dev, void *res)
1330 {
1331         struct region_devres *this = res;
1332
1333         __release_region(this->parent, this->start, this->n);
1334 }
1335
1336 static int devm_region_match(struct device *dev, void *res, void *match_data)
1337 {
1338         struct region_devres *this = res, *match = match_data;
1339
1340         return this->parent == match->parent &&
1341                 this->start == match->start && this->n == match->n;
1342 }
1343
1344 struct resource * __devm_request_region(struct device *dev,
1345                                 struct resource *parent, resource_size_t start,
1346                                 resource_size_t n, const char *name)
1347 {
1348         struct region_devres *dr = NULL;
1349         struct resource *res;
1350
1351         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1352                           GFP_KERNEL);
1353         if (!dr)
1354                 return NULL;
1355
1356         dr->parent = parent;
1357         dr->start = start;
1358         dr->n = n;
1359
1360         res = __request_region(parent, start, n, name, 0);
1361         if (res)
1362                 devres_add(dev, dr);
1363         else
1364                 devres_free(dr);
1365
1366         return res;
1367 }
1368 EXPORT_SYMBOL(__devm_request_region);
1369
1370 void __devm_release_region(struct device *dev, struct resource *parent,
1371                            resource_size_t start, resource_size_t n)
1372 {
1373         struct region_devres match_data = { parent, start, n };
1374
1375         __release_region(parent, start, n);
1376         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1377                                &match_data));
1378 }
1379 EXPORT_SYMBOL(__devm_release_region);
1380
1381 /*
1382  * Called from init/main.c to reserve IO ports.
1383  */
1384 #define MAXRESERVE 4
1385 static int __init reserve_setup(char *str)
1386 {
1387         static int reserved;
1388         static struct resource reserve[MAXRESERVE];
1389
1390         for (;;) {
1391                 unsigned int io_start, io_num;
1392                 int x = reserved;
1393
1394                 if (get_option (&str, &io_start) != 2)
1395                         break;
1396                 if (get_option (&str, &io_num)   == 0)
1397                         break;
1398                 if (x < MAXRESERVE) {
1399                         struct resource *res = reserve + x;
1400                         res->name = "reserved";
1401                         res->start = io_start;
1402                         res->end = io_start + io_num - 1;
1403                         res->flags = IORESOURCE_BUSY;
1404                         res->child = NULL;
1405                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1406                                 reserved = x+1;
1407                 }
1408         }
1409         return 1;
1410 }
1411
1412 __setup("reserve=", reserve_setup);
1413
1414 /*
1415  * Check if the requested addr and size spans more than any slot in the
1416  * iomem resource tree.
1417  */
1418 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1419 {
1420         struct resource *p = &iomem_resource;
1421         int err = 0;
1422         loff_t l;
1423
1424         read_lock(&resource_lock);
1425         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1426                 /*
1427                  * We can probably skip the resources without
1428                  * IORESOURCE_IO attribute?
1429                  */
1430                 if (p->start >= addr + size)
1431                         continue;
1432                 if (p->end < addr)
1433                         continue;
1434                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1435                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1436                         continue;
1437                 /*
1438                  * if a resource is "BUSY", it's not a hardware resource
1439                  * but a driver mapping of such a resource; we don't want
1440                  * to warn for those; some drivers legitimately map only
1441                  * partial hardware resources. (example: vesafb)
1442                  */
1443                 if (p->flags & IORESOURCE_BUSY)
1444                         continue;
1445
1446                 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1447                        (unsigned long long)addr,
1448                        (unsigned long long)(addr + size - 1),
1449                        p->name, p);
1450                 err = -1;
1451                 break;
1452         }
1453         read_unlock(&resource_lock);
1454
1455         return err;
1456 }
1457
1458 #ifdef CONFIG_STRICT_DEVMEM
1459 static int strict_iomem_checks = 1;
1460 #else
1461 static int strict_iomem_checks;
1462 #endif
1463
1464 /*
1465  * check if an address is reserved in the iomem resource tree
1466  * returns 1 if reserved, 0 if not reserved.
1467  */
1468 int iomem_is_exclusive(u64 addr)
1469 {
1470         struct resource *p = &iomem_resource;
1471         int err = 0;
1472         loff_t l;
1473         int size = PAGE_SIZE;
1474
1475         if (!strict_iomem_checks)
1476                 return 0;
1477
1478         addr = addr & PAGE_MASK;
1479
1480         read_lock(&resource_lock);
1481         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1482                 /*
1483                  * We can probably skip the resources without
1484                  * IORESOURCE_IO attribute?
1485                  */
1486                 if (p->start >= addr + size)
1487                         break;
1488                 if (p->end < addr)
1489                         continue;
1490                 if (p->flags & IORESOURCE_BUSY &&
1491                      p->flags & IORESOURCE_EXCLUSIVE) {
1492                         err = 1;
1493                         break;
1494                 }
1495         }
1496         read_unlock(&resource_lock);
1497
1498         return err;
1499 }
1500
1501 struct resource_entry *resource_list_create_entry(struct resource *res,
1502                                                   size_t extra_size)
1503 {
1504         struct resource_entry *entry;
1505
1506         entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1507         if (entry) {
1508                 INIT_LIST_HEAD(&entry->node);
1509                 entry->res = res ? res : &entry->__res;
1510         }
1511
1512         return entry;
1513 }
1514 EXPORT_SYMBOL(resource_list_create_entry);
1515
1516 void resource_list_free(struct list_head *head)
1517 {
1518         struct resource_entry *entry, *tmp;
1519
1520         list_for_each_entry_safe(entry, tmp, head, node)
1521                 resource_list_destroy_entry(entry);
1522 }
1523 EXPORT_SYMBOL(resource_list_free);
1524
1525 static int __init strict_iomem(char *str)
1526 {
1527         if (strstr(str, "relaxed"))
1528                 strict_iomem_checks = 0;
1529         if (strstr(str, "strict"))
1530                 strict_iomem_checks = 1;
1531         return 1;
1532 }
1533
1534 __setup("iomem=", strict_iomem);