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 <linux/mm.h>
  25#include <asm/io.h>
  26
  27
  28struct resource ioport_resource = {
  29        .name   = "PCI IO",
  30        .start  = 0,
  31        .end    = IO_SPACE_LIMIT,
  32        .flags  = IORESOURCE_IO,
  33};
  34EXPORT_SYMBOL(ioport_resource);
  35
  36struct resource iomem_resource = {
  37        .name   = "PCI mem",
  38        .start  = 0,
  39        .end    = -1,
  40        .flags  = IORESOURCE_MEM,
  41};
  42EXPORT_SYMBOL(iomem_resource);
  43
  44/* constraints to be met while allocating resources */
  45struct resource_constraint {
  46        resource_size_t min, max, align;
  47        resource_size_t (*alignf)(void *, const struct resource *,
  48                        resource_size_t, resource_size_t);
  49        void *alignf_data;
  50};
  51
  52static DEFINE_RWLOCK(resource_lock);
  53
  54/*
  55 * For memory hotplug, there is no way to free resource entries allocated
  56 * by boot mem after the system is up. So for reusing the resource entry
  57 * we need to remember the resource.
  58 */
  59static struct resource *bootmem_resource_free;
  60static DEFINE_SPINLOCK(bootmem_resource_lock);
  61
  62static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  63{
  64        struct resource *p = v;
  65        (*pos)++;
  66        if (p->child)
  67                return p->child;
  68        while (!p->sibling && p->parent)
  69                p = p->parent;
  70        return p->sibling;
  71}
  72
  73#ifdef CONFIG_PROC_FS
  74
  75enum { MAX_IORES_LEVEL = 5 };
  76
  77static void *r_start(struct seq_file *m, loff_t *pos)
  78        __acquires(resource_lock)
  79{
  80        struct resource *p = m->private;
  81        loff_t l = 0;
  82        read_lock(&resource_lock);
  83        for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  84                ;
  85        return p;
  86}
  87
  88static void r_stop(struct seq_file *m, void *v)
  89        __releases(resource_lock)
  90{
  91        read_unlock(&resource_lock);
  92}
  93
  94static int r_show(struct seq_file *m, void *v)
  95{
  96        struct resource *root = m->private;
  97        struct resource *r = v, *p;
  98        int width = root->end < 0x10000 ? 4 : 8;
  99        int depth;
 100
 101        for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
 102                if (p->parent == root)
 103                        break;
 104        seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
 105                        depth * 2, "",
 106                        width, (unsigned long long) r->start,
 107                        width, (unsigned long long) r->end,
 108                        r->name ? r->name : "<BAD>");
 109        return 0;
 110}
 111
 112static const struct seq_operations resource_op = {
 113        .start  = r_start,
 114        .next   = r_next,
 115        .stop   = r_stop,
 116        .show   = r_show,
 117};
 118
 119static int ioports_open(struct inode *inode, struct file *file)
 120{
 121        int res = seq_open(file, &resource_op);
 122        if (!res) {
 123                struct seq_file *m = file->private_data;
 124                m->private = &ioport_resource;
 125        }
 126        return res;
 127}
 128
 129static int iomem_open(struct inode *inode, struct file *file)
 130{
 131        int res = seq_open(file, &resource_op);
 132        if (!res) {
 133                struct seq_file *m = file->private_data;
 134                m->private = &iomem_resource;
 135        }
 136        return res;
 137}
 138
 139static const struct file_operations proc_ioports_operations = {
 140        .open           = ioports_open,
 141        .read           = seq_read,
 142        .llseek         = seq_lseek,
 143        .release        = seq_release,
 144};
 145
 146static const struct file_operations proc_iomem_operations = {
 147        .open           = iomem_open,
 148        .read           = seq_read,
 149        .llseek         = seq_lseek,
 150        .release        = seq_release,
 151};
 152
 153static int __init ioresources_init(void)
 154{
 155        proc_create("ioports", 0, NULL, &proc_ioports_operations);
 156        proc_create("iomem", 0, NULL, &proc_iomem_operations);
 157        return 0;
 158}
 159__initcall(ioresources_init);
 160
 161#endif /* CONFIG_PROC_FS */
 162
 163static void free_resource(struct resource *res)
 164{
 165        if (!res)
 166                return;
 167
 168        if (!PageSlab(virt_to_head_page(res))) {
 169                spin_lock(&bootmem_resource_lock);
 170                res->sibling = bootmem_resource_free;
 171                bootmem_resource_free = res;
 172                spin_unlock(&bootmem_resource_lock);
 173        } else {
 174                kfree(res);
 175        }
 176}
 177
 178static struct resource *alloc_resource(gfp_t flags)
 179{
 180        struct resource *res = NULL;
 181
 182        spin_lock(&bootmem_resource_lock);
 183        if (bootmem_resource_free) {
 184                res = bootmem_resource_free;
 185                bootmem_resource_free = res->sibling;
 186        }
 187        spin_unlock(&bootmem_resource_lock);
 188
 189        if (res)
 190                memset(res, 0, sizeof(struct resource));
 191        else
 192                res = kzalloc(sizeof(struct resource), flags);
 193
 194        return res;
 195}
 196
 197/* Return the conflict entry if you can't request it */
 198static struct resource * __request_resource(struct resource *root, struct resource *new)
 199{
 200        resource_size_t start = new->start;
 201        resource_size_t end = new->end;
 202        struct resource *tmp, **p;
 203
 204        if (end < start)
 205                return root;
 206        if (start < root->start)
 207                return root;
 208        if (end > root->end)
 209                return root;
 210        p = &root->child;
 211        for (;;) {
 212                tmp = *p;
 213                if (!tmp || tmp->start > end) {
 214                        new->sibling = tmp;
 215                        *p = new;
 216                        new->parent = root;
 217                        return NULL;
 218                }
 219                p = &tmp->sibling;
 220                if (tmp->end < start)
 221                        continue;
 222                return tmp;
 223        }
 224}
 225
 226static int __release_resource(struct resource *old)
 227{
 228        struct resource *tmp, **p;
 229
 230        p = &old->parent->child;
 231        for (;;) {
 232                tmp = *p;
 233                if (!tmp)
 234                        break;
 235                if (tmp == old) {
 236                        *p = tmp->sibling;
 237                        old->parent = NULL;
 238                        return 0;
 239                }
 240                p = &tmp->sibling;
 241        }
 242        return -EINVAL;
 243}
 244
 245static void __release_child_resources(struct resource *r)
 246{
 247        struct resource *tmp, *p;
 248        resource_size_t size;
 249
 250        p = r->child;
 251        r->child = NULL;
 252        while (p) {
 253                tmp = p;
 254                p = p->sibling;
 255
 256                tmp->parent = NULL;
 257                tmp->sibling = NULL;
 258                __release_child_resources(tmp);
 259
 260                printk(KERN_DEBUG "release child resource %pR\n", tmp);
 261                /* need to restore size, and keep flags */
 262                size = resource_size(tmp);
 263                tmp->start = 0;
 264                tmp->end = size - 1;
 265        }
 266}
 267
 268void release_child_resources(struct resource *r)
 269{
 270        write_lock(&resource_lock);
 271        __release_child_resources(r);
 272        write_unlock(&resource_lock);
 273}
 274
 275/**
 276 * request_resource_conflict - request and reserve an I/O or memory resource
 277 * @root: root resource descriptor
 278 * @new: resource descriptor desired by caller
 279 *
 280 * Returns 0 for success, conflict resource on error.
 281 */
 282struct resource *request_resource_conflict(struct resource *root, struct resource *new)
 283{
 284        struct resource *conflict;
 285
 286        write_lock(&resource_lock);
 287        conflict = __request_resource(root, new);
 288        write_unlock(&resource_lock);
 289        return conflict;
 290}
 291
 292/**
 293 * request_resource - request and reserve an I/O or memory resource
 294 * @root: root resource descriptor
 295 * @new: resource descriptor desired by caller
 296 *
 297 * Returns 0 for success, negative error code on error.
 298 */
 299int request_resource(struct resource *root, struct resource *new)
 300{
 301        struct resource *conflict;
 302
 303        conflict = request_resource_conflict(root, new);
 304        return conflict ? -EBUSY : 0;
 305}
 306
 307EXPORT_SYMBOL(request_resource);
 308
 309/**
 310 * release_resource - release a previously reserved resource
 311 * @old: resource pointer
 312 */
 313int release_resource(struct resource *old)
 314{
 315        int retval;
 316
 317        write_lock(&resource_lock);
 318        retval = __release_resource(old);
 319        write_unlock(&resource_lock);
 320        return retval;
 321}
 322
 323EXPORT_SYMBOL(release_resource);
 324
 325#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 326/*
 327 * Finds the lowest memory reosurce exists within [res->start.res->end)
 328 * the caller must specify res->start, res->end, res->flags and "name".
 329 * If found, returns 0, res is overwritten, if not found, returns -1.
 330 */
 331static int find_next_system_ram(struct resource *res, char *name)
 332{
 333        resource_size_t start, end;
 334        struct resource *p;
 335
 336        BUG_ON(!res);
 337
 338        start = res->start;
 339        end = res->end;
 340        BUG_ON(start >= end);
 341
 342        read_lock(&resource_lock);
 343        for (p = iomem_resource.child; p ; p = p->sibling) {
 344                /* system ram is just marked as IORESOURCE_MEM */
 345                if (p->flags != res->flags)
 346                        continue;
 347                if (name && strcmp(p->name, name))
 348                        continue;
 349                if (p->start > end) {
 350                        p = NULL;
 351                        break;
 352                }
 353                if ((p->end >= start) && (p->start < end))
 354                        break;
 355        }
 356        read_unlock(&resource_lock);
 357        if (!p)
 358                return -1;
 359        /* copy data */
 360        if (res->start < p->start)
 361                res->start = p->start;
 362        if (res->end > p->end)
 363                res->end = p->end;
 364        return 0;
 365}
 366
 367/*
 368 * This function calls callback against all memory range of "System RAM"
 369 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 370 * Now, this function is only for "System RAM".
 371 */
 372int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 373                void *arg, int (*func)(unsigned long, unsigned long, void *))
 374{
 375        struct resource res;
 376        unsigned long pfn, end_pfn;
 377        u64 orig_end;
 378        int ret = -1;
 379
 380        res.start = (u64) start_pfn << PAGE_SHIFT;
 381        res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 382        res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 383        orig_end = res.end;
 384        while ((res.start < res.end) &&
 385                (find_next_system_ram(&res, "System RAM") >= 0)) {
 386                pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 387                end_pfn = (res.end + 1) >> PAGE_SHIFT;
 388                if (end_pfn > pfn)
 389                        ret = (*func)(pfn, end_pfn - pfn, arg);
 390                if (ret)
 391                        break;
 392                res.start = res.end + 1;
 393                res.end = orig_end;
 394        }
 395        return ret;
 396}
 397
 398#endif
 399
 400static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 401{
 402        return 1;
 403}
 404/*
 405 * This generic page_is_ram() returns true if specified address is
 406 * registered as "System RAM" in iomem_resource list.
 407 */
 408int __weak page_is_ram(unsigned long pfn)
 409{
 410        return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 411}
 412EXPORT_SYMBOL_GPL(page_is_ram);
 413
 414void __weak arch_remove_reservations(struct resource *avail)
 415{
 416}
 417
 418static resource_size_t simple_align_resource(void *data,
 419                                             const struct resource *avail,
 420                                             resource_size_t size,
 421                                             resource_size_t align)
 422{
 423        return avail->start;
 424}
 425
 426static void resource_clip(struct resource *res, resource_size_t min,
 427                          resource_size_t max)
 428{
 429        if (res->start < min)
 430                res->start = min;
 431        if (res->end > max)
 432                res->end = max;
 433}
 434
 435static bool resource_contains(struct resource *res1, struct resource *res2)
 436{
 437        return res1->start <= res2->start && res1->end >= res2->end;
 438}
 439
 440/*
 441 * Find empty slot in the resource tree with the given range and
 442 * alignment constraints
 443 */
 444static int __find_resource(struct resource *root, struct resource *old,
 445                         struct resource *new,
 446                         resource_size_t  size,
 447                         struct resource_constraint *constraint)
 448{
 449        struct resource *this = root->child;
 450        struct resource tmp = *new, avail, alloc;
 451
 452        tmp.start = root->start;
 453        /*
 454         * Skip past an allocated resource that starts at 0, since the assignment
 455         * of this->start - 1 to tmp->end below would cause an underflow.
 456         */
 457        if (this && this->start == root->start) {
 458                tmp.start = (this == old) ? old->start : this->end + 1;
 459                this = this->sibling;
 460        }
 461        for(;;) {
 462                if (this)
 463                        tmp.end = (this == old) ?  this->end : this->start - 1;
 464                else
 465                        tmp.end = root->end;
 466
 467                if (tmp.end < tmp.start)
 468                        goto next;
 469
 470                resource_clip(&tmp, constraint->min, constraint->max);
 471                arch_remove_reservations(&tmp);
 472
 473                /* Check for overflow after ALIGN() */
 474                avail = *new;
 475                avail.start = ALIGN(tmp.start, constraint->align);
 476                avail.end = tmp.end;
 477                if (avail.start >= tmp.start) {
 478                        alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 479                                        size, constraint->align);
 480                        alloc.end = alloc.start + size - 1;
 481                        if (resource_contains(&avail, &alloc)) {
 482                                new->start = alloc.start;
 483                                new->end = alloc.end;
 484                                return 0;
 485                        }
 486                }
 487
 488next:           if (!this || this->end == root->end)
 489                        break;
 490
 491                if (this != old)
 492                        tmp.start = this->end + 1;
 493                this = this->sibling;
 494        }
 495        return -EBUSY;
 496}
 497
 498/*
 499 * Find empty slot in the resource tree given range and alignment.
 500 */
 501static int find_resource(struct resource *root, struct resource *new,
 502                        resource_size_t size,
 503                        struct resource_constraint  *constraint)
 504{
 505        return  __find_resource(root, NULL, new, size, constraint);
 506}
 507
 508/**
 509 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
 510 *      The resource will be relocated if the new size cannot be reallocated in the
 511 *      current location.
 512 *
 513 * @root: root resource descriptor
 514 * @old:  resource descriptor desired by caller
 515 * @newsize: new size of the resource descriptor
 516 * @constraint: the size and alignment constraints to be met.
 517 */
 518int reallocate_resource(struct resource *root, struct resource *old,
 519                        resource_size_t newsize,
 520                        struct resource_constraint  *constraint)
 521{
 522        int err=0;
 523        struct resource new = *old;
 524        struct resource *conflict;
 525
 526        write_lock(&resource_lock);
 527
 528        if ((err = __find_resource(root, old, &new, newsize, constraint)))
 529                goto out;
 530
 531        if (resource_contains(&new, old)) {
 532                old->start = new.start;
 533                old->end = new.end;
 534                goto out;
 535        }
 536
 537        if (old->child) {
 538                err = -EBUSY;
 539                goto out;
 540        }
 541
 542        if (resource_contains(old, &new)) {
 543                old->start = new.start;
 544                old->end = new.end;
 545        } else {
 546                __release_resource(old);
 547                *old = new;
 548                conflict = __request_resource(root, old);
 549                BUG_ON(conflict);
 550        }
 551out:
 552        write_unlock(&resource_lock);
 553        return err;
 554}
 555
 556
 557/**
 558 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
 559 *      The resource will be reallocated with a new size if it was already allocated
 560 * @root: root resource descriptor
 561 * @new: resource descriptor desired by caller
 562 * @size: requested resource region size
 563 * @min: minimum boundary to allocate
 564 * @max: maximum boundary to allocate
 565 * @align: alignment requested, in bytes
 566 * @alignf: alignment function, optional, called if not NULL
 567 * @alignf_data: arbitrary data to pass to the @alignf function
 568 */
 569int allocate_resource(struct resource *root, struct resource *new,
 570                      resource_size_t size, resource_size_t min,
 571                      resource_size_t max, resource_size_t align,
 572                      resource_size_t (*alignf)(void *,
 573                                                const struct resource *,
 574                                                resource_size_t,
 575                                                resource_size_t),
 576                      void *alignf_data)
 577{
 578        int err;
 579        struct resource_constraint constraint;
 580
 581        if (!alignf)
 582                alignf = simple_align_resource;
 583
 584        constraint.min = min;
 585        constraint.max = max;
 586        constraint.align = align;
 587        constraint.alignf = alignf;
 588        constraint.alignf_data = alignf_data;
 589
 590        if ( new->parent ) {
 591                /* resource is already allocated, try reallocating with
 592                   the new constraints */
 593                return reallocate_resource(root, new, size, &constraint);
 594        }
 595
 596        write_lock(&resource_lock);
 597        err = find_resource(root, new, size, &constraint);
 598        if (err >= 0 && __request_resource(root, new))
 599                err = -EBUSY;
 600        write_unlock(&resource_lock);
 601        return err;
 602}
 603
 604EXPORT_SYMBOL(allocate_resource);
 605
 606/**
 607 * lookup_resource - find an existing resource by a resource start address
 608 * @root: root resource descriptor
 609 * @start: resource start address
 610 *
 611 * Returns a pointer to the resource if found, NULL otherwise
 612 */
 613struct resource *lookup_resource(struct resource *root, resource_size_t start)
 614{
 615        struct resource *res;
 616
 617        read_lock(&resource_lock);
 618        for (res = root->child; res; res = res->sibling) {
 619                if (res->start == start)
 620                        break;
 621        }
 622        read_unlock(&resource_lock);
 623
 624        return res;
 625}
 626
 627/*
 628 * Insert a resource into the resource tree. If successful, return NULL,
 629 * otherwise return the conflicting resource (compare to __request_resource())
 630 */
 631static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 632{
 633        struct resource *first, *next;
 634
 635        for (;; parent = first) {
 636                first = __request_resource(parent, new);
 637                if (!first)
 638                        return first;
 639
 640                if (first == parent)
 641                        return first;
 642                if (WARN_ON(first == new))      /* duplicated insertion */
 643                        return first;
 644
 645                if ((first->start > new->start) || (first->end < new->end))
 646                        break;
 647                if ((first->start == new->start) && (first->end == new->end))
 648                        break;
 649        }
 650
 651        for (next = first; ; next = next->sibling) {
 652                /* Partial overlap? Bad, and unfixable */
 653                if (next->start < new->start || next->end > new->end)
 654                        return next;
 655                if (!next->sibling)
 656                        break;
 657                if (next->sibling->start > new->end)
 658                        break;
 659        }
 660
 661        new->parent = parent;
 662        new->sibling = next->sibling;
 663        new->child = first;
 664
 665        next->sibling = NULL;
 666        for (next = first; next; next = next->sibling)
 667                next->parent = new;
 668
 669        if (parent->child == first) {
 670                parent->child = new;
 671        } else {
 672                next = parent->child;
 673                while (next->sibling != first)
 674                        next = next->sibling;
 675                next->sibling = new;
 676        }
 677        return NULL;
 678}
 679
 680/**
 681 * insert_resource_conflict - Inserts resource in the resource tree
 682 * @parent: parent of the new resource
 683 * @new: new resource to insert
 684 *
 685 * Returns 0 on success, conflict resource if the resource can't be inserted.
 686 *
 687 * This function is equivalent to request_resource_conflict when no conflict
 688 * happens. If a conflict happens, and the conflicting resources
 689 * entirely fit within the range of the new resource, then the new
 690 * resource is inserted and the conflicting resources become children of
 691 * the new resource.
 692 */
 693struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 694{
 695        struct resource *conflict;
 696
 697        write_lock(&resource_lock);
 698        conflict = __insert_resource(parent, new);
 699        write_unlock(&resource_lock);
 700        return conflict;
 701}
 702
 703/**
 704 * insert_resource - Inserts a resource in the resource tree
 705 * @parent: parent of the new resource
 706 * @new: new resource to insert
 707 *
 708 * Returns 0 on success, -EBUSY if the resource can't be inserted.
 709 */
 710int insert_resource(struct resource *parent, struct resource *new)
 711{
 712        struct resource *conflict;
 713
 714        conflict = insert_resource_conflict(parent, new);
 715        return conflict ? -EBUSY : 0;
 716}
 717
 718/**
 719 * insert_resource_expand_to_fit - Insert a resource into the resource tree
 720 * @root: root resource descriptor
 721 * @new: new resource to insert
 722 *
 723 * Insert a resource into the resource tree, possibly expanding it in order
 724 * to make it encompass any conflicting resources.
 725 */
 726void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 727{
 728        if (new->parent)
 729                return;
 730
 731        write_lock(&resource_lock);
 732        for (;;) {
 733                struct resource *conflict;
 734
 735                conflict = __insert_resource(root, new);
 736                if (!conflict)
 737                        break;
 738                if (conflict == root)
 739                        break;
 740
 741                /* Ok, expand resource to cover the conflict, then try again .. */
 742                if (conflict->start < new->start)
 743                        new->start = conflict->start;
 744                if (conflict->end > new->end)
 745                        new->end = conflict->end;
 746
 747                printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 748        }
 749        write_unlock(&resource_lock);
 750}
 751
 752static int __adjust_resource(struct resource *res, resource_size_t start,
 753                                resource_size_t size)
 754{
 755        struct resource *tmp, *parent = res->parent;
 756        resource_size_t end = start + size - 1;
 757        int result = -EBUSY;
 758
 759        if (!parent)
 760                goto skip;
 761
 762        if ((start < parent->start) || (end > parent->end))
 763                goto out;
 764
 765        if (res->sibling && (res->sibling->start <= end))
 766                goto out;
 767
 768        tmp = parent->child;
 769        if (tmp != res) {
 770                while (tmp->sibling != res)
 771                        tmp = tmp->sibling;
 772                if (start <= tmp->end)
 773                        goto out;
 774        }
 775
 776skip:
 777        for (tmp = res->child; tmp; tmp = tmp->sibling)
 778                if ((tmp->start < start) || (tmp->end > end))
 779                        goto out;
 780
 781        res->start = start;
 782        res->end = end;
 783        result = 0;
 784
 785 out:
 786        return result;
 787}
 788
 789/**
 790 * adjust_resource - modify a resource's start and size
 791 * @res: resource to modify
 792 * @start: new start value
 793 * @size: new size
 794 *
 795 * Given an existing resource, change its start and size to match the
 796 * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 797 * Existing children of the resource are assumed to be immutable.
 798 */
 799int adjust_resource(struct resource *res, resource_size_t start,
 800                        resource_size_t size)
 801{
 802        int result;
 803
 804        write_lock(&resource_lock);
 805        result = __adjust_resource(res, start, size);
 806        write_unlock(&resource_lock);
 807        return result;
 808}
 809EXPORT_SYMBOL(adjust_resource);
 810
 811static void __init __reserve_region_with_split(struct resource *root,
 812                resource_size_t start, resource_size_t end,
 813                const char *name)
 814{
 815        struct resource *parent = root;
 816        struct resource *conflict;
 817        struct resource *res = alloc_resource(GFP_ATOMIC);
 818        struct resource *next_res = NULL;
 819
 820        if (!res)
 821                return;
 822
 823        res->name = name;
 824        res->start = start;
 825        res->end = end;
 826        res->flags = IORESOURCE_BUSY;
 827
 828        while (1) {
 829
 830                conflict = __request_resource(parent, res);
 831                if (!conflict) {
 832                        if (!next_res)
 833                                break;
 834                        res = next_res;
 835                        next_res = NULL;
 836                        continue;
 837                }
 838
 839                /* conflict covered whole area */
 840                if (conflict->start <= res->start &&
 841                                conflict->end >= res->end) {
 842                        free_resource(res);
 843                        WARN_ON(next_res);
 844                        break;
 845                }
 846
 847                /* failed, split and try again */
 848                if (conflict->start > res->start) {
 849                        end = res->end;
 850                        res->end = conflict->start - 1;
 851                        if (conflict->end < end) {
 852                                next_res = alloc_resource(GFP_ATOMIC);
 853                                if (!next_res) {
 854                                        free_resource(res);
 855                                        break;
 856                                }
 857                                next_res->name = name;
 858                                next_res->start = conflict->end + 1;
 859                                next_res->end = end;
 860                                next_res->flags = IORESOURCE_BUSY;
 861                        }
 862                } else {
 863                        res->start = conflict->end + 1;
 864                }
 865        }
 866
 867}
 868
 869void __init reserve_region_with_split(struct resource *root,
 870                resource_size_t start, resource_size_t end,
 871                const char *name)
 872{
 873        int abort = 0;
 874
 875        write_lock(&resource_lock);
 876        if (root->start > start || root->end < end) {
 877                pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
 878                       (unsigned long long)start, (unsigned long long)end,
 879                       root);
 880                if (start > root->end || end < root->start)
 881                        abort = 1;
 882                else {
 883                        if (end > root->end)
 884                                end = root->end;
 885                        if (start < root->start)
 886                                start = root->start;
 887                        pr_err("fixing request to [0x%llx-0x%llx]\n",
 888                               (unsigned long long)start,
 889                               (unsigned long long)end);
 890                }
 891                dump_stack();
 892        }
 893        if (!abort)
 894                __reserve_region_with_split(root, start, end, name);
 895        write_unlock(&resource_lock);
 896}
 897
 898/**
 899 * resource_alignment - calculate resource's alignment
 900 * @res: resource pointer
 901 *
 902 * Returns alignment on success, 0 (invalid alignment) on failure.
 903 */
 904resource_size_t resource_alignment(struct resource *res)
 905{
 906        switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 907        case IORESOURCE_SIZEALIGN:
 908                return resource_size(res);
 909        case IORESOURCE_STARTALIGN:
 910                return res->start;
 911        default:
 912                return 0;
 913        }
 914}
 915
 916/*
 917 * This is compatibility stuff for IO resources.
 918 *
 919 * Note how this, unlike the above, knows about
 920 * the IO flag meanings (busy etc).
 921 *
 922 * request_region creates a new busy region.
 923 *
 924 * check_region returns non-zero if the area is already busy.
 925 *
 926 * release_region releases a matching busy region.
 927 */
 928
 929static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
 930
 931/**
 932 * __request_region - create a new busy resource region
 933 * @parent: parent resource descriptor
 934 * @start: resource start address
 935 * @n: resource region size
 936 * @name: reserving caller's ID string
 937 * @flags: IO resource flags
 938 */
 939struct resource * __request_region(struct resource *parent,
 940                                   resource_size_t start, resource_size_t n,
 941                                   const char *name, int flags)
 942{
 943        DECLARE_WAITQUEUE(wait, current);
 944        struct resource *res = alloc_resource(GFP_KERNEL);
 945
 946        if (!res)
 947                return NULL;
 948
 949        res->name = name;
 950        res->start = start;
 951        res->end = start + n - 1;
 952        res->flags = IORESOURCE_BUSY;
 953        res->flags |= flags;
 954
 955        write_lock(&resource_lock);
 956
 957        for (;;) {
 958                struct resource *conflict;
 959
 960                conflict = __request_resource(parent, res);
 961                if (!conflict)
 962                        break;
 963                if (conflict != parent) {
 964                        parent = conflict;
 965                        if (!(conflict->flags & IORESOURCE_BUSY))
 966                                continue;
 967                }
 968                if (conflict->flags & flags & IORESOURCE_MUXED) {
 969                        add_wait_queue(&muxed_resource_wait, &wait);
 970                        write_unlock(&resource_lock);
 971                        set_current_state(TASK_UNINTERRUPTIBLE);
 972                        schedule();
 973                        remove_wait_queue(&muxed_resource_wait, &wait);
 974                        write_lock(&resource_lock);
 975                        continue;
 976                }
 977                /* Uhhuh, that didn't work out.. */
 978                free_resource(res);
 979                res = NULL;
 980                break;
 981        }
 982        write_unlock(&resource_lock);
 983        return res;
 984}
 985EXPORT_SYMBOL(__request_region);
 986
 987/**
 988 * __check_region - check if a resource region is busy or free
 989 * @parent: parent resource descriptor
 990 * @start: resource start address
 991 * @n: resource region size
 992 *
 993 * Returns 0 if the region is free at the moment it is checked,
 994 * returns %-EBUSY if the region is busy.
 995 *
 996 * NOTE:
 997 * This function is deprecated because its use is racy.
 998 * Even if it returns 0, a subsequent call to request_region()
 999 * may fail because another driver etc. just allocated the region.
1000 * Do NOT use it.  It will be removed from the kernel.
1001 */
1002int __check_region(struct resource *parent, resource_size_t start,
1003                        resource_size_t n)
1004{
1005        struct resource * res;
1006
1007        res = __request_region(parent, start, n, "check-region", 0);
1008        if (!res)
1009                return -EBUSY;
1010
1011        release_resource(res);
1012        free_resource(res);
1013        return 0;
1014}
1015EXPORT_SYMBOL(__check_region);
1016
1017/**
1018 * __release_region - release a previously reserved resource region
1019 * @parent: parent resource descriptor
1020 * @start: resource start address
1021 * @n: resource region size
1022 *
1023 * The described resource region must match a currently busy region.
1024 */
1025void __release_region(struct resource *parent, resource_size_t start,
1026                        resource_size_t n)
1027{
1028        struct resource **p;
1029        resource_size_t end;
1030
1031        p = &parent->child;
1032        end = start + n - 1;
1033
1034        write_lock(&resource_lock);
1035
1036        for (;;) {
1037                struct resource *res = *p;
1038
1039                if (!res)
1040                        break;
1041                if (res->start <= start && res->end >= end) {
1042                        if (!(res->flags & IORESOURCE_BUSY)) {
1043                                p = &res->child;
1044                                continue;
1045                        }
1046                        if (res->start != start || res->end != end)
1047                                break;
1048                        *p = res->sibling;
1049                        write_unlock(&resource_lock);
1050                        if (res->flags & IORESOURCE_MUXED)
1051                                wake_up(&muxed_resource_wait);
1052                        free_resource(res);
1053                        return;
1054                }
1055                p = &res->sibling;
1056        }
1057
1058        write_unlock(&resource_lock);
1059
1060        printk(KERN_WARNING "Trying to free nonexistent resource "
1061                "<%016llx-%016llx>\n", (unsigned long long)start,
1062                (unsigned long long)end);
1063}
1064EXPORT_SYMBOL(__release_region);
1065
1066#ifdef CONFIG_MEMORY_HOTREMOVE
1067/**
1068 * release_mem_region_adjustable - release a previously reserved memory region
1069 * @parent: parent resource descriptor
1070 * @start: resource start address
1071 * @size: resource region size
1072 *
1073 * This interface is intended for memory hot-delete.  The requested region
1074 * is released from a currently busy memory resource.  The requested region
1075 * must either match exactly or fit into a single busy resource entry.  In
1076 * the latter case, the remaining resource is adjusted accordingly.
1077 * Existing children of the busy memory resource must be immutable in the
1078 * request.
1079 *
1080 * Note:
1081 * - Additional release conditions, such as overlapping region, can be
1082 *   supported after they are confirmed as valid cases.
1083 * - When a busy memory resource gets split into two entries, the code
1084 *   assumes that all children remain in the lower address entry for
1085 *   simplicity.  Enhance this logic when necessary.
1086 */
1087int release_mem_region_adjustable(struct resource *parent,
1088                        resource_size_t start, resource_size_t size)
1089{
1090        struct resource **p;
1091        struct resource *res;
1092        struct resource *new_res;
1093        resource_size_t end;
1094        int ret = -EINVAL;
1095
1096        end = start + size - 1;
1097        if ((start < parent->start) || (end > parent->end))
1098                return ret;
1099
1100        /* The alloc_resource() result gets checked later */
1101        new_res = alloc_resource(GFP_KERNEL);
1102
1103        p = &parent->child;
1104        write_lock(&resource_lock);
1105
1106        while ((res = *p)) {
1107                if (res->start >= end)
1108                        break;
1109
1110                /* look for the next resource if it does not fit into */
1111                if (res->start > start || res->end < end) {
1112                        p = &res->sibling;
1113                        continue;
1114                }
1115
1116                if (!(res->flags & IORESOURCE_MEM))
1117                        break;
1118
1119                if (!(res->flags & IORESOURCE_BUSY)) {
1120                        p = &res->child;
1121                        continue;
1122                }
1123
1124                /* found the target resource; let's adjust accordingly */
1125                if (res->start == start && res->end == end) {
1126                        /* free the whole entry */
1127                        *p = res->sibling;
1128                        free_resource(res);
1129                        ret = 0;
1130                } else if (res->start == start && res->end != end) {
1131                        /* adjust the start */
1132                        ret = __adjust_resource(res, end + 1,
1133                                                res->end - end);
1134                } else if (res->start != start && res->end == end) {
1135                        /* adjust the end */
1136                        ret = __adjust_resource(res, res->start,
1137                                                start - res->start);
1138                } else {
1139                        /* split into two entries */
1140                        if (!new_res) {
1141                                ret = -ENOMEM;
1142                                break;
1143                        }
1144                        new_res->name = res->name;
1145                        new_res->start = end + 1;
1146                        new_res->end = res->end;
1147                        new_res->flags = res->flags;
1148                        new_res->parent = res->parent;
1149                        new_res->sibling = res->sibling;
1150                        new_res->child = NULL;
1151
1152                        ret = __adjust_resource(res, res->start,
1153                                                start - res->start);
1154                        if (ret)
1155                                break;
1156                        res->sibling = new_res;
1157                        new_res = NULL;
1158                }
1159
1160                break;
1161        }
1162
1163        write_unlock(&resource_lock);
1164        free_resource(new_res);
1165        return ret;
1166}
1167#endif  /* CONFIG_MEMORY_HOTREMOVE */
1168
1169/*
1170 * Managed region resource
1171 */
1172struct region_devres {
1173        struct resource *parent;
1174        resource_size_t start;
1175        resource_size_t n;
1176};
1177
1178static void devm_region_release(struct device *dev, void *res)
1179{
1180        struct region_devres *this = res;
1181
1182        __release_region(this->parent, this->start, this->n);
1183}
1184
1185static int devm_region_match(struct device *dev, void *res, void *match_data)
1186{
1187        struct region_devres *this = res, *match = match_data;
1188
1189        return this->parent == match->parent &&
1190                this->start == match->start && this->n == match->n;
1191}
1192
1193struct resource * __devm_request_region(struct device *dev,
1194                                struct resource *parent, resource_size_t start,
1195                                resource_size_t n, const char *name)
1196{
1197        struct region_devres *dr = NULL;
1198        struct resource *res;
1199
1200        dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1201                          GFP_KERNEL);
1202        if (!dr)
1203                return NULL;
1204
1205        dr->parent = parent;
1206        dr->start = start;
1207        dr->n = n;
1208
1209        res = __request_region(parent, start, n, name, 0);
1210        if (res)
1211                devres_add(dev, dr);
1212        else
1213                devres_free(dr);
1214
1215        return res;
1216}
1217EXPORT_SYMBOL(__devm_request_region);
1218
1219void __devm_release_region(struct device *dev, struct resource *parent,
1220                           resource_size_t start, resource_size_t n)
1221{
1222        struct region_devres match_data = { parent, start, n };
1223
1224        __release_region(parent, start, n);
1225        WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1226                               &match_data));
1227}
1228EXPORT_SYMBOL(__devm_release_region);
1229
1230/*
1231 * Called from init/main.c to reserve IO ports.
1232 */
1233#define MAXRESERVE 4
1234static int __init reserve_setup(char *str)
1235{
1236        static int reserved;
1237        static struct resource reserve[MAXRESERVE];
1238
1239        for (;;) {
1240                unsigned int io_start, io_num;
1241                int x = reserved;
1242
1243                if (get_option (&str, &io_start) != 2)
1244                        break;
1245                if (get_option (&str, &io_num)   == 0)
1246                        break;
1247                if (x < MAXRESERVE) {
1248                        struct resource *res = reserve + x;
1249                        res->name = "reserved";
1250                        res->start = io_start;
1251                        res->end = io_start + io_num - 1;
1252                        res->flags = IORESOURCE_BUSY;
1253                        res->child = NULL;
1254                        if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1255                                reserved = x+1;
1256                }
1257        }
1258        return 1;
1259}
1260
1261__setup("reserve=", reserve_setup);
1262
1263/*
1264 * Check if the requested addr and size spans more than any slot in the
1265 * iomem resource tree.
1266 */
1267int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1268{
1269        struct resource *p = &iomem_resource;
1270        int err = 0;
1271        loff_t l;
1272
1273        read_lock(&resource_lock);
1274        for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1275                /*
1276                 * We can probably skip the resources without
1277                 * IORESOURCE_IO attribute?
1278                 */
1279                if (p->start >= addr + size)
1280                        continue;
1281                if (p->end < addr)
1282                        continue;
1283                if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1284                    PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1285                        continue;
1286                /*
1287                 * if a resource is "BUSY", it's not a hardware resource
1288                 * but a driver mapping of such a resource; we don't want
1289                 * to warn for those; some drivers legitimately map only
1290                 * partial hardware resources. (example: vesafb)
1291                 */
1292                if (p->flags & IORESOURCE_BUSY)
1293                        continue;
1294
1295                printk(KERN_WARNING "resource map sanity check conflict: "
1296                       "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
1297                       (unsigned long long)addr,
1298                       (unsigned long long)(addr + size - 1),
1299                       (unsigned long long)p->start,
1300                       (unsigned long long)p->end,
1301                       p->name);
1302                err = -1;
1303                break;
1304        }
1305        read_unlock(&resource_lock);
1306
1307        return err;
1308}
1309
1310#ifdef CONFIG_STRICT_DEVMEM
1311static int strict_iomem_checks = 1;
1312#else
1313static int strict_iomem_checks;
1314#endif
1315
1316/*
1317 * check if an address is reserved in the iomem resource tree
1318 * returns 1 if reserved, 0 if not reserved.
1319 */
1320int iomem_is_exclusive(u64 addr)
1321{
1322        struct resource *p = &iomem_resource;
1323        int err = 0;
1324        loff_t l;
1325        int size = PAGE_SIZE;
1326
1327        if (!strict_iomem_checks)
1328                return 0;
1329
1330        addr = addr & PAGE_MASK;
1331
1332        read_lock(&resource_lock);
1333        for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1334                /*
1335                 * We can probably skip the resources without
1336                 * IORESOURCE_IO attribute?
1337                 */
1338                if (p->start >= addr + size)
1339                        break;
1340                if (p->end < addr)
1341                        continue;
1342                if (p->flags & IORESOURCE_BUSY &&
1343                     p->flags & IORESOURCE_EXCLUSIVE) {
1344                        err = 1;
1345                        break;
1346                }
1347        }
1348        read_unlock(&resource_lock);
1349
1350        return err;
1351}
1352
1353static int __init strict_iomem(char *str)
1354{
1355        if (strstr(str, "relaxed"))
1356                strict_iomem_checks = 0;
1357        if (strstr(str, "strict"))
1358                strict_iomem_checks = 1;
1359        return 1;
1360}
1361
1362__setup("iomem=", strict_iomem);
1363
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