linux/kernel/resource.c
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   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
  27struct resource ioport_resource = {
  28        .name   = "PCI IO",
  29        .start  = 0,
  30        .end    = IO_SPACE_LIMIT,
  31        .flags  = IORESOURCE_IO,
  32};
  33EXPORT_SYMBOL(ioport_resource);
  34
  35struct resource iomem_resource = {
  36        .name   = "PCI mem",
  37        .start  = 0,
  38        .end    = -1,
  39        .flags  = IORESOURCE_MEM,
  40};
  41EXPORT_SYMBOL(iomem_resource);
  42
  43/* constraints to be met while allocating resources */
  44struct 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
  51static DEFINE_RWLOCK(resource_lock);
  52
  53static 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
  66enum { MAX_IORES_LEVEL = 5 };
  67
  68static 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
  79static void r_stop(struct seq_file *m, void *v)
  80        __releases(resource_lock)
  81{
  82        read_unlock(&resource_lock);
  83}
  84
  85static 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
 103static const struct seq_operations resource_op = {
 104        .start  = r_start,
 105        .next   = r_next,
 106        .stop   = r_stop,
 107        .show   = r_show,
 108};
 109
 110static 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
 120static 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
 130static 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
 137static 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
 144static 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 */
 155static 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
 183static 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
 202static 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
 225void 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 */
 239struct 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 */
 256int 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
 264EXPORT_SYMBOL(request_resource);
 265
 266/**
 267 * release_resource - release a previously reserved resource
 268 * @old: resource pointer
 269 */
 270int 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
 280EXPORT_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 */
 288static 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 */
 329int 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
 357static 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 */
 365int __weak page_is_ram(unsigned long pfn)
 366{
 367        return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 368}
 369
 370void __weak arch_remove_reservations(struct resource *avail)
 371{
 372}
 373
 374static 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
 382static 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
 391static 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 */
 400static 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
 445next:           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 */
 458static 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 */
 475int 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        }
 508out:
 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 */
 526int 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
 561EXPORT_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 */
 570struct 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 */
 588static 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 */
 650struct 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 */
 667int 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 */
 683void 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 */
 719int 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
 744skip:
 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}
 757EXPORT_SYMBOL(adjust_resource);
 758
 759static 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
 818void __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 */
 853resource_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
 878static 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 */
 888struct 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}
 934EXPORT_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 */
 951int __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}
 964EXPORT_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 */
 974void __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}
1013EXPORT_SYMBOL(__release_region);
1014
1015/*
1016 * Managed region resource
1017 */
1018struct region_devres {
1019        struct resource *parent;
1020        resource_size_t start;
1021        resource_size_t n;
1022};
1023
1024static 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
1031static 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
1039struct 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}
1063EXPORT_SYMBOL(__devm_request_region);
1064
1065void __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}
1074EXPORT_SYMBOL(__devm_release_region);
1075
1076/*
1077 * Called from init/main.c to reserve IO ports.
1078 */
1079#define MAXRESERVE 4
1080static 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 */
1113int 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
1157static int strict_iomem_checks = 1;
1158#else
1159static 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 */
1166int 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
1199static 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);
1209
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