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