kernel/resource.c

   1 /*
   2  *      linux/kernel/resource.c
   3  *
   4  * Copyright (C) 1999   Linus Torvalds
   5  * Copyright (C) 1999   Martin Mares <mj@ucw.cz>
   6  *
   7  * Arbitrary resource management.
   8  */
   9
  10 #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/seq_file.h>
  19 #include <linux/device.h>
  20 #include <linux/pfn.h>
  21 #include <asm/io.h>
  22
  23
  24 struct resource ioport_resource = {
  25         .name   = "PCI IO",
  26         .start  = 0,
  27         .end    = IO_SPACE_LIMIT,
  28         .flags  = IORESOURCE_IO,
  29 };
  30 EXPORT_SYMBOL(ioport_resource);
  31
  32 struct resource iomem_resource = {
  33         .name   = "PCI mem",
  34         .start  = 0,
  35         .end    = -1,
  36         .flags  = IORESOURCE_MEM,
  37 };
  38 EXPORT_SYMBOL(iomem_resource);
  39
  40 static DEFINE_RWLOCK(resource_lock);
  41
  42 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  43 {
  44         struct resource *p = v;
  45         (*pos)++;
  46         if (p->child)
  47                 return p->child;
  48         while (!p->sibling && p->parent)
  49                 p = p->parent;
  50         return p->sibling;
  51 }
  52
  53 #ifdef CONFIG_PROC_FS
  54
  55 enum { MAX_IORES_LEVEL = 5 };
  56
  57 static void *r_start(struct seq_file *m, loff_t *pos)
  58         __acquires(resource_lock)
  59 {
  60         struct resource *p = m->private;
  61         loff_t l = 0;
  62         read_lock(&resource_lock);
  63         for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  64                 ;
  65         return p;
  66 }
  67
  68 static void r_stop(struct seq_file *m, void *v)
  69         __releases(resource_lock)
  70 {
  71         read_unlock(&resource_lock);
  72 }
  73
  74 static int r_show(struct seq_file *m, void *v)
  75 {
  76         struct resource *root = m->private;
  77         struct resource *r = v, *p;
  78         int width = root->end < 0x10000 ? 4 : 8;
  79         int depth;
  80
  81         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
  82                 if (p->parent == root)
  83                         break;
  84         seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
  85                         depth * 2, "",
  86                         width, (unsigned long long) r->start,
  87                         width, (unsigned long long) r->end,
  88                         r->name ? r->name : "<BAD>");
  89         return 0;
  90 }
  91
  92 static const struct seq_operations resource_op = {
  93         .start  = r_start,
  94         .next   = r_next,
  95         .stop   = r_stop,
  96         .show   = r_show,
  97 };
  98
  99 static int ioports_open(struct inode *inode, struct file *file)
 100 {
 101         int res = seq_open(file, &resource_op);
 102         if (!res) {
 103                 struct seq_file *m = file->private_data;
 104                 m->private = &ioport_resource;
 105         }
 106         return res;
 107 }
 108
 109 static int iomem_open(struct inode *inode, struct file *file)
 110 {
 111         int res = seq_open(file, &resource_op);
 112         if (!res) {
 113                 struct seq_file *m = file->private_data;
 114                 m->private = &iomem_resource;
 115         }
 116         return res;
 117 }
 118
 119 static const struct file_operations proc_ioports_operations = {
 120         .open           = ioports_open,
 121         .read           = seq_read,
 122         .llseek         = seq_lseek,
 123         .release        = seq_release,
 124 };
 125
 126 static const struct file_operations proc_iomem_operations = {
 127         .open           = iomem_open,
 128         .read           = seq_read,
 129         .llseek         = seq_lseek,
 130         .release        = seq_release,
 131 };
 132
 133 static int __init ioresources_init(void)
 134 {
 135         proc_create("ioports", 0, NULL, &proc_ioports_operations);
 136         proc_create("iomem", 0, NULL, &proc_iomem_operations);
 137         return 0;
 138 }
 139 __initcall(ioresources_init);
 140
 141 #endif /* CONFIG_PROC_FS */
 142
 143 /* Return the conflict entry if you can't request it */
 144 static struct resource * __request_resource(struct resource *root, struct resource *new)
 145 {
 146         resource_size_t start = new->start;
 147         resource_size_t end = new->end;
 148         struct resource *tmp, **p;
 149
 150         if (end < start)
 151                 return root;
 152         if (start < root->start)
 153                 return root;
 154         if (end > root->end)
 155                 return root;
 156         p = &root->child;
 157         for (;;) {
 158                 tmp = *p;
 159                 if (!tmp || tmp->start > end) {
 160                         new->sibling = tmp;
 161                         *p = new;
 162                         new->parent = root;
 163                         return NULL;
 164                 }
 165                 p = &tmp->sibling;
 166                 if (tmp->end < start)
 167                         continue;
 168                 return tmp;
 169         }
 170 }
 171
 172 static int __release_resource(struct resource *old)
 173 {
 174         struct resource *tmp, **p;
 175
 176         p = &old->parent->child;
 177         for (;;) {
 178                 tmp = *p;
 179                 if (!tmp)
 180                         break;
 181                 if (tmp == old) {
 182                         *p = tmp->sibling;
 183                         old->parent = NULL;
 184                         return 0;
 185                 }
 186                 p = &tmp->sibling;
 187         }
 188         return -EINVAL;
 189 }
 190
 191 /**
 192  * request_resource - request and reserve an I/O or memory resource
 193  * @root: root resource descriptor
 194  * @new: resource descriptor desired by caller
 195  *
 196  * Returns 0 for success, negative error code on error.
 197  */
 198 int request_resource(struct resource *root, struct resource *new)
 199 {
 200         struct resource *conflict;
 201
 202         write_lock(&resource_lock);
 203         conflict = __request_resource(root, new);
 204         write_unlock(&resource_lock);
 205         return conflict ? -EBUSY : 0;
 206 }
 207
 208 EXPORT_SYMBOL(request_resource);
 209
 210 /**
 211  * release_resource - release a previously reserved resource
 212  * @old: resource pointer
 213  */
 214 int release_resource(struct resource *old)
 215 {
 216         int retval;
 217
 218         write_lock(&resource_lock);
 219         retval = __release_resource(old);
 220         write_unlock(&resource_lock);
 221         return retval;
 222 }
 223
 224 EXPORT_SYMBOL(release_resource);
 225
 226 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 227 /*
 228  * Finds the lowest memory reosurce exists within [res->start.res->end)
 229  * the caller must specify res->start, res->end, res->flags and "name".
 230  * If found, returns 0, res is overwritten, if not found, returns -1.
 231  */
 232 static int find_next_system_ram(struct resource *res, char *name)
 233 {
 234         resource_size_t start, end;
 235         struct resource *p;
 236
 237         BUG_ON(!res);
 238
 239         start = res->start;
 240         end = res->end;
 241         BUG_ON(start >= end);
 242
 243         read_lock(&resource_lock);
 244         for (p = iomem_resource.child; p ; p = p->sibling) {
 245                 /* system ram is just marked as IORESOURCE_MEM */
 246                 if (p->flags != res->flags)
 247                         continue;
 248                 if (name && strcmp(p->name, name))
 249                         continue;
 250                 if (p->start > end) {
 251                         p = NULL;
 252                         break;
 253                 }
 254                 if ((p->end >= start) && (p->start < end))
 255                         break;
 256         }
 257         read_unlock(&resource_lock);
 258         if (!p)
 259                 return -1;
 260         /* copy data */
 261         if (res->start < p->start)
 262                 res->start = p->start;
 263         if (res->end > p->end)
 264                 res->end = p->end;
 265         return 0;
 266 }
 267
 268 /*
 269  * This function calls callback against all memory range of "System RAM"
 270  * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 271  * Now, this function is only for "System RAM".
 272  */
 273 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 274                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 275 {
 276         struct resource res;
 277         unsigned long pfn, len;
 278         u64 orig_end;
 279         int ret = -1;
 280
 281         res.start = (u64) start_pfn << PAGE_SHIFT;
 282         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 283         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 284         orig_end = res.end;
 285         while ((res.start < res.end) &&
 286                 (find_next_system_ram(&res, "System RAM") >= 0)) {
 287                 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
 288                 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
 289                 ret = (*func)(pfn, len, arg);
 290                 if (ret)
 291                         break;
 292                 res.start = res.end + 1;
 293                 res.end = orig_end;
 294         }
 295         return ret;
 296 }
 297
 298 #endif
 299
 300 /*
 301  * Find empty slot in the resource tree given range and alignment.
 302  */
 303 static int find_resource(struct resource *root, struct resource *new,
 304                          resource_size_t size, resource_size_t min,
 305                          resource_size_t max, resource_size_t align,
 306                          void (*alignf)(void *, struct resource *,
 307                                         resource_size_t, resource_size_t),
 308                          void *alignf_data)
 309 {
 310         struct resource *this = root->child;
 311
 312         new->start = root->start;
 313         /*
 314          * Skip past an allocated resource that starts at 0, since the assignment
 315          * of this->start - 1 to new->end below would cause an underflow.
 316          */
 317         if (this && this->start == 0) {
 318                 new->start = this->end + 1;
 319                 this = this->sibling;
 320         }
 321         for(;;) {
 322                 if (this)
 323                         new->end = this->start - 1;
 324                 else
 325                         new->end = root->end;
 326                 if (new->start < min)
 327                         new->start = min;
 328                 if (new->end > max)
 329                         new->end = max;
 330                 new->start = ALIGN(new->start, align);
 331                 if (alignf)
 332                         alignf(alignf_data, new, size, align);
 333                 if (new->start < new->end && new->end - new->start >= size - 1) {
 334                         new->end = new->start + size - 1;
 335                         return 0;
 336                 }
 337                 if (!this)
 338                         break;
 339                 new->start = this->end + 1;
 340                 this = this->sibling;
 341         }
 342         return -EBUSY;
 343 }
 344
 345 /**
 346  * allocate_resource - allocate empty slot in the resource tree given range & alignment
 347  * @root: root resource descriptor
 348  * @new: resource descriptor desired by caller
 349  * @size: requested resource region size
 350  * @min: minimum size to allocate
 351  * @max: maximum size to allocate
 352  * @align: alignment requested, in bytes
 353  * @alignf: alignment function, optional, called if not NULL
 354  * @alignf_data: arbitrary data to pass to the @alignf function
 355  */
 356 int allocate_resource(struct resource *root, struct resource *new,
 357                       resource_size_t size, resource_size_t min,
 358                       resource_size_t max, resource_size_t align,
 359                       void (*alignf)(void *, struct resource *,
 360                                      resource_size_t, resource_size_t),
 361                       void *alignf_data)
 362 {
 363         int err;
 364
 365         write_lock(&resource_lock);
 366         err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
 367         if (err >= 0 && __request_resource(root, new))
 368                 err = -EBUSY;
 369         write_unlock(&resource_lock);
 370         return err;
 371 }
 372
 373 EXPORT_SYMBOL(allocate_resource);
 374
 375 /*
 376  * Insert a resource into the resource tree. If successful, return NULL,
 377  * otherwise return the conflicting resource (compare to __request_resource())
 378  */
 379 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 380 {
 381         struct resource *first, *next;
 382
 383         for (;; parent = first) {
 384                 first = __request_resource(parent, new);
 385                 if (!first)
 386                         return first;
 387
 388                 if (first == parent)
 389                         return first;
 390
 391                 if ((first->start > new->start) || (first->end < new->end))
 392                         break;
 393                 if ((first->start == new->start) && (first->end == new->end))
 394                         break;
 395         }
 396
 397         for (next = first; ; next = next->sibling) {
 398                 /* Partial overlap? Bad, and unfixable */
 399                 if (next->start < new->start || next->end > new->end)
 400                         return next;
 401                 if (!next->sibling)
 402                         break;
 403                 if (next->sibling->start > new->end)
 404                         break;
 405         }
 406
 407         new->parent = parent;
 408         new->sibling = next->sibling;
 409         new->child = first;
 410
 411         next->sibling = NULL;
 412         for (next = first; next; next = next->sibling)
 413                 next->parent = new;
 414
 415         if (parent->child == first) {
 416                 parent->child = new;
 417         } else {
 418                 next = parent->child;
 419                 while (next->sibling != first)
 420                         next = next->sibling;
 421                 next->sibling = new;
 422         }
 423         return NULL;
 424 }
 425
 426 /**
 427  * insert_resource - Inserts a resource in the resource tree
 428  * @parent: parent of the new resource
 429  * @new: new resource to insert
 430  *
 431  * Returns 0 on success, -EBUSY if the resource can't be inserted.
 432  *
 433  * This function is equivalent to request_resource when no conflict
 434  * happens. If a conflict happens, and the conflicting resources
 435  * entirely fit within the range of the new resource, then the new
 436  * resource is inserted and the conflicting resources become children of
 437  * the new resource.
 438  */
 439 int insert_resource(struct resource *parent, struct resource *new)
 440 {
 441         struct resource *conflict;
 442
 443         write_lock(&resource_lock);
 444         conflict = __insert_resource(parent, new);
 445         write_unlock(&resource_lock);
 446         return conflict ? -EBUSY : 0;
 447 }
 448
 449 /**
 450  * insert_resource_expand_to_fit - Insert a resource into the resource tree
 451  * @root: root resource descriptor
 452  * @new: new resource to insert
 453  *
 454  * Insert a resource into the resource tree, possibly expanding it in order
 455  * to make it encompass any conflicting resources.
 456  */
 457 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 458 {
 459         if (new->parent)
 460                 return;
 461
 462         write_lock(&resource_lock);
 463         for (;;) {
 464                 struct resource *conflict;
 465
 466                 conflict = __insert_resource(root, new);
 467                 if (!conflict)
 468                         break;
 469                 if (conflict == root)
 470                         break;
 471
 472                 /* Ok, expand resource to cover the conflict, then try again .. */
 473                 if (conflict->start < new->start)
 474                         new->start = conflict->start;
 475                 if (conflict->end > new->end)
 476                         new->end = conflict->end;
 477
 478                 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 479         }
 480         write_unlock(&resource_lock);
 481 }
 482
 483 /**
 484  * adjust_resource - modify a resource's start and size
 485  * @res: resource to modify
 486  * @start: new start value
 487  * @size: new size
 488  *
 489  * Given an existing resource, change its start and size to match the
 490  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 491  * Existing children of the resource are assumed to be immutable.
 492  */
 493 int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
 494 {
 495         struct resource *tmp, *parent = res->parent;
 496         resource_size_t end = start + size - 1;
 497         int result = -EBUSY;
 498
 499         write_lock(&resource_lock);
 500
 501         if ((start < parent->start) || (end > parent->end))
 502                 goto out;
 503
 504         for (tmp = res->child; tmp; tmp = tmp->sibling) {
 505                 if ((tmp->start < start) || (tmp->end > end))
 506                         goto out;
 507         }
 508
 509         if (res->sibling && (res->sibling->start <= end))
 510                 goto out;
 511
 512         tmp = parent->child;
 513         if (tmp != res) {
 514                 while (tmp->sibling != res)
 515                         tmp = tmp->sibling;
 516                 if (start <= tmp->end)
 517                         goto out;
 518         }
 519
 520         res->start = start;
 521         res->end = end;
 522         result = 0;
 523
 524  out:
 525         write_unlock(&resource_lock);
 526         return result;
 527 }
 528
 529 static void __init __reserve_region_with_split(struct resource *root,
 530                 resource_size_t start, resource_size_t end,
 531                 const char *name)
 532 {
 533         struct resource *parent = root;
 534         struct resource *conflict;
 535         struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
 536
 537         if (!res)
 538                 return;
 539
 540         res->name = name;
 541         res->start = start;
 542         res->end = end;
 543         res->flags = IORESOURCE_BUSY;
 544
 545         conflict = __request_resource(parent, res);
 546         if (!conflict)
 547                 return;
 548
 549         /* failed, split and try again */
 550         kfree(res);
 551
 552         /* conflict covered whole area */
 553         if (conflict->start <= start && conflict->end >= end)
 554                 return;
 555
 556         if (conflict->start > start)
 557                 __reserve_region_with_split(root, start, conflict->start-1, name);
 558         if (conflict->end < end)
 559                 __reserve_region_with_split(root, conflict->end+1, end, name);
 560 }
 561
 562 void __init reserve_region_with_split(struct resource *root,
 563                 resource_size_t start, resource_size_t end,
 564                 const char *name)
 565 {
 566         write_lock(&resource_lock);
 567         __reserve_region_with_split(root, start, end, name);
 568         write_unlock(&resource_lock);
 569 }
 570
 571 EXPORT_SYMBOL(adjust_resource);
 572
 573 /**
 574  * resource_alignment - calculate resource's alignment
 575  * @res: resource pointer
 576  *
 577  * Returns alignment on success, 0 (invalid alignment) on failure.
 578  */
 579 resource_size_t resource_alignment(struct resource *res)
 580 {
 581         switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 582         case IORESOURCE_SIZEALIGN:
 583                 return resource_size(res);
 584         case IORESOURCE_STARTALIGN:
 585                 return res->start;
 586         default:
 587                 return 0;
 588         }
 589 }
 590
 591 /*
 592  * This is compatibility stuff for IO resources.
 593  *
 594  * Note how this, unlike the above, knows about
 595  * the IO flag meanings (busy etc).
 596  *
 597  * request_region creates a new busy region.
 598  *
 599  * check_region returns non-zero if the area is already busy.
 600  *
 601  * release_region releases a matching busy region.
 602  */
 603
 604 /**
 605  * __request_region - create a new busy resource region
 606  * @parent: parent resource descriptor
 607  * @start: resource start address
 608  * @n: resource region size
 609  * @name: reserving caller's ID string
 610  * @flags: IO resource flags
 611  */
 612 struct resource * __request_region(struct resource *parent,
 613                                    resource_size_t start, resource_size_t n,
 614                                    const char *name, int flags)
 615 {
 616         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 617
 618         if (!res)
 619                 return NULL;
 620
 621         res->name = name;
 622         res->start = start;
 623         res->end = start + n - 1;
 624         res->flags = IORESOURCE_BUSY;
 625         res->flags |= flags;
 626
 627         write_lock(&resource_lock);
 628
 629         for (;;) {
 630                 struct resource *conflict;
 631
 632                 conflict = __request_resource(parent, res);
 633                 if (!conflict)
 634                         break;
 635                 if (conflict != parent) {
 636                         parent = conflict;
 637                         if (!(conflict->flags & IORESOURCE_BUSY))
 638                                 continue;
 639                 }
 640
 641                 /* Uhhuh, that didn't work out.. */
 642                 kfree(res);
 643                 res = NULL;
 644                 break;
 645         }
 646         write_unlock(&resource_lock);
 647         return res;
 648 }
 649 EXPORT_SYMBOL(__request_region);
 650
 651 /**
 652  * __check_region - check if a resource region is busy or free
 653  * @parent: parent resource descriptor
 654  * @start: resource start address
 655  * @n: resource region size
 656  *
 657  * Returns 0 if the region is free at the moment it is checked,
 658  * returns %-EBUSY if the region is busy.
 659  *
 660  * NOTE:
 661  * This function is deprecated because its use is racy.
 662  * Even if it returns 0, a subsequent call to request_region()
 663  * may fail because another driver etc. just allocated the region.
 664  * Do NOT use it.  It will be removed from the kernel.
 665  */
 666 int __check_region(struct resource *parent, resource_size_t start,
 667                         resource_size_t n)
 668 {
 669         struct resource * res;
 670
 671         res = __request_region(parent, start, n, "check-region", 0);
 672         if (!res)
 673                 return -EBUSY;
 674
 675         release_resource(res);
 676         kfree(res);
 677         return 0;
 678 }
 679 EXPORT_SYMBOL(__check_region);
 680
 681 /**
 682  * __release_region - release a previously reserved resource region
 683  * @parent: parent resource descriptor
 684  * @start: resource start address
 685  * @n: resource region size
 686  *
 687  * The described resource region must match a currently busy region.
 688  */
 689 void __release_region(struct resource *parent, resource_size_t start,
 690                         resource_size_t n)
 691 {
 692         struct resource **p;
 693         resource_size_t end;
 694
 695         p = &parent->child;
 696         end = start + n - 1;
 697
 698         write_lock(&resource_lock);
 699
 700         for (;;) {
 701                 struct resource *res = *p;
 702
 703                 if (!res)
 704                         break;
 705                 if (res->start <= start && res->end >= end) {
 706                         if (!(res->flags & IORESOURCE_BUSY)) {
 707                                 p = &res->child;
 708                                 continue;
 709                         }
 710                         if (res->start != start || res->end != end)
 711                                 break;
 712                         *p = res->sibling;
 713                         write_unlock(&resource_lock);
 714                         kfree(res);
 715                         return;
 716                 }
 717                 p = &res->sibling;
 718         }
 719
 720         write_unlock(&resource_lock);
 721
 722         printk(KERN_WARNING "Trying to free nonexistent resource "
 723                 "<%016llx-%016llx>\n", (unsigned long long)start,
 724                 (unsigned long long)end);
 725 }
 726 EXPORT_SYMBOL(__release_region);
 727
 728 /*
 729  * Managed region resource
 730  */
 731 struct region_devres {
 732         struct resource *parent;
 733         resource_size_t start;
 734         resource_size_t n;
 735 };
 736
 737 static void devm_region_release(struct device *dev, void *res)
 738 {
 739         struct region_devres *this = res;
 740
 741         __release_region(this->parent, this->start, this->n);
 742 }
 743
 744 static int devm_region_match(struct device *dev, void *res, void *match_data)
 745 {
 746         struct region_devres *this = res, *match = match_data;
 747
 748         return this->parent == match->parent &&
 749                 this->start == match->start && this->n == match->n;
 750 }
 751
 752 struct resource * __devm_request_region(struct device *dev,
 753                                 struct resource *parent, resource_size_t start,
 754                                 resource_size_t n, const char *name)
 755 {
 756         struct region_devres *dr = NULL;
 757         struct resource *res;
 758
 759         dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
 760                           GFP_KERNEL);
 761         if (!dr)
 762                 return NULL;
 763
 764         dr->parent = parent;
 765         dr->start = start;
 766         dr->n = n;
 767
 768         res = __request_region(parent, start, n, name, 0);
 769         if (res)
 770                 devres_add(dev, dr);
 771         else
 772                 devres_free(dr);
 773
 774         return res;
 775 }
 776 EXPORT_SYMBOL(__devm_request_region);
 777
 778 void __devm_release_region(struct device *dev, struct resource *parent,
 779                            resource_size_t start, resource_size_t n)
 780 {
 781         struct region_devres match_data = { parent, start, n };
 782
 783         __release_region(parent, start, n);
 784         WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
 785                                &match_data));
 786 }
 787 EXPORT_SYMBOL(__devm_release_region);
 788
 789 /*
 790  * Called from init/main.c to reserve IO ports.
 791  */
 792 #define MAXRESERVE 4
 793 static int __init reserve_setup(char *str)
 794 {
 795         static int reserved;
 796         static struct resource reserve[MAXRESERVE];
 797
 798         for (;;) {
 799                 unsigned int io_start, io_num;
 800                 int x = reserved;
 801
 802                 if (get_option (&str, &io_start) != 2)
 803                         break;
 804                 if (get_option (&str, &io_num)   == 0)
 805                         break;
 806                 if (x < MAXRESERVE) {
 807                         struct resource *res = reserve + x;
 808                         res->name = "reserved";
 809                         res->start = io_start;
 810                         res->end = io_start + io_num - 1;
 811                         res->flags = IORESOURCE_BUSY;
 812                         res->child = NULL;
 813                         if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
 814                                 reserved = x+1;
 815                 }
 816         }
 817         return 1;
 818 }
 819
 820 __setup("reserve=", reserve_setup);
 821
 822 /*
 823  * Check if the requested addr and size spans more than any slot in the
 824  * iomem resource tree.
 825  */
 826 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 827 {
 828         struct resource *p = &iomem_resource;
 829         int err = 0;
 830         loff_t l;
 831
 832         read_lock(&resource_lock);
 833         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 834                 /*
 835                  * We can probably skip the resources without
 836                  * IORESOURCE_IO attribute?
 837                  */
 838                 if (p->start >= addr + size)
 839                         continue;
 840                 if (p->end < addr)
 841                         continue;
 842                 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
 843                     PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
 844                         continue;
 845                 /*
 846                  * if a resource is "BUSY", it's not a hardware resource
 847                  * but a driver mapping of such a resource; we don't want
 848                  * to warn for those; some drivers legitimately map only
 849                  * partial hardware resources. (example: vesafb)
 850                  */
 851                 if (p->flags & IORESOURCE_BUSY)
 852                         continue;
 853
 854                 printk(KERN_WARNING "resource map sanity check conflict: "
 855                        "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
 856                        (unsigned long long)addr,
 857                        (unsigned long long)(addr + size - 1),
 858                        (unsigned long long)p->start,
 859                        (unsigned long long)p->end,
 860                        p->name);
 861                 err = -1;
 862                 break;
 863         }
 864         read_unlock(&resource_lock);
 865
 866         return err;
 867 }
 868
 869 #ifdef CONFIG_STRICT_DEVMEM
 870 static int strict_iomem_checks = 1;
 871 #else
 872 static int strict_iomem_checks;
 873 #endif
 874
 875 /*
 876  * check if an address is reserved in the iomem resource tree
 877  * returns 1 if reserved, 0 if not reserved.
 878  */
 879 int iomem_is_exclusive(u64 addr)
 880 {
 881         struct resource *p = &iomem_resource;
 882         int err = 0;
 883         loff_t l;
 884         int size = PAGE_SIZE;
 885
 886         if (!strict_iomem_checks)
 887                 return 0;
 888
 889         addr = addr & PAGE_MASK;
 890
 891         read_lock(&resource_lock);
 892         for (p = p->child; p ; p = r_next(NULL, p, &l)) {
 893                 /*
 894                  * We can probably skip the resources without
 895                  * IORESOURCE_IO attribute?
 896                  */
 897                 if (p->start >= addr + size)
 898                         break;
 899                 if (p->end < addr)
 900                         continue;
 901                 if (p->flags & IORESOURCE_BUSY &&
 902                      p->flags & IORESOURCE_EXCLUSIVE) {
 903                         err = 1;
 904                         break;
 905                 }
 906         }
 907         read_unlock(&resource_lock);
 908
 909         return err;
 910 }
 911
 912 static int __init strict_iomem(char *str)
 913 {
 914         if (strstr(str, "relaxed"))
 915                 strict_iomem_checks = 0;
 916         if (strstr(str, "strict"))
 917                 strict_iomem_checks = 1;
 918         return 1;
 919 }
 920
 921 __setup("iomem=", strict_iomem);