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