arch/x86/mm/ioremap.c

   1 /*
   2  * Re-map IO memory to kernel address space so that we can access it.
   3  * This is needed for high PCI addresses that aren't mapped in the
   4  * 640k-1MB IO memory area on PC's
   5  *
   6  * (C) Copyright 1995 1996 Linus Torvalds
   7  */
   8
   9 #include <linux/bootmem.h>
  10 #include <linux/init.h>
  11 #include <linux/io.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/mmiotrace.h>
  16
  17 #include <asm/cacheflush.h>
  18 #include <asm/e820.h>
  19 #include <asm/fixmap.h>
  20 #include <asm/pgtable.h>
  21 #include <asm/tlbflush.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/pat.h>
  24
  25 #ifdef CONFIG_X86_64
  26
  27 static inline int phys_addr_valid(unsigned long addr)
  28 {
  29         return addr < (1UL << boot_cpu_data.x86_phys_bits);
  30 }
  31
  32 unsigned long __phys_addr(unsigned long x)
  33 {
  34         if (x >= __START_KERNEL_map) {
  35                 x -= __START_KERNEL_map;
  36                 VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
  37                 x += phys_base;
  38         } else {
  39                 VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  40                 x -= PAGE_OFFSET;
  41                 VIRTUAL_BUG_ON(system_state == SYSTEM_BOOTING ? x > MAXMEM :
  42                                         !phys_addr_valid(x));
  43         }
  44         return x;
  45 }
  46 EXPORT_SYMBOL(__phys_addr);
  47
  48 bool __virt_addr_valid(unsigned long x)
  49 {
  50         if (x >= __START_KERNEL_map) {
  51                 x -= __START_KERNEL_map;
  52                 if (x >= KERNEL_IMAGE_SIZE)
  53                         return false;
  54                 x += phys_base;
  55         } else {
  56                 if (x < PAGE_OFFSET)
  57                         return false;
  58                 x -= PAGE_OFFSET;
  59                 if (system_state == SYSTEM_BOOTING ?
  60                                 x > MAXMEM : !phys_addr_valid(x)) {
  61                         return false;
  62                 }
  63         }
  64
  65         return pfn_valid(x >> PAGE_SHIFT);
  66 }
  67 EXPORT_SYMBOL(__virt_addr_valid);
  68
  69 #else
  70
  71 static inline int phys_addr_valid(unsigned long addr)
  72 {
  73         return 1;
  74 }
  75
  76 #ifdef CONFIG_DEBUG_VIRTUAL
  77 unsigned long __phys_addr(unsigned long x)
  78 {
  79         /* VMALLOC_* aren't constants  */
  80         VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  81         VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
  82         return x - PAGE_OFFSET;
  83 }
  84 EXPORT_SYMBOL(__phys_addr);
  85 #endif
  86
  87 bool __virt_addr_valid(unsigned long x)
  88 {
  89         if (x < PAGE_OFFSET)
  90                 return false;
  91         if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
  92                 return false;
  93         return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
  94 }
  95 EXPORT_SYMBOL(__virt_addr_valid);
  96
  97 #endif
  98
  99 int page_is_ram(unsigned long pagenr)
 100 {
 101         resource_size_t addr, end;
 102         int i;
 103
 104         /*
 105          * A special case is the first 4Kb of memory;
 106          * This is a BIOS owned area, not kernel ram, but generally
 107          * not listed as such in the E820 table.
 108          */
 109         if (pagenr == 0)
 110                 return 0;
 111
 112         /*
 113          * Second special case: Some BIOSen report the PC BIOS
 114          * area (640->1Mb) as ram even though it is not.
 115          */
 116         if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
 117                     pagenr < (BIOS_END >> PAGE_SHIFT))
 118                 return 0;
 119
 120         for (i = 0; i < e820.nr_map; i++) {
 121                 /*
 122                  * Not usable memory:
 123                  */
 124                 if (e820.map[i].type != E820_RAM)
 125                         continue;
 126                 addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
 127                 end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
 128
 129
 130                 if ((pagenr >= addr) && (pagenr < end))
 131                         return 1;
 132         }
 133         return 0;
 134 }
 135
 136 /*
 137  * Fix up the linear direct mapping of the kernel to avoid cache attribute
 138  * conflicts.
 139  */
 140 int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 141                                unsigned long prot_val)
 142 {
 143         unsigned long nrpages = size >> PAGE_SHIFT;
 144         int err;
 145
 146         switch (prot_val) {
 147         case _PAGE_CACHE_UC:
 148         default:
 149                 err = _set_memory_uc(vaddr, nrpages);
 150                 break;
 151         case _PAGE_CACHE_WC:
 152                 err = _set_memory_wc(vaddr, nrpages);
 153                 break;
 154         case _PAGE_CACHE_WB:
 155                 err = _set_memory_wb(vaddr, nrpages);
 156                 break;
 157         }
 158
 159         return err;
 160 }
 161
 162 /*
 163  * Remap an arbitrary physical address space into the kernel virtual
 164  * address space. Needed when the kernel wants to access high addresses
 165  * directly.
 166  *
 167  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 168  * have to convert them into an offset in a page-aligned mapping, but the
 169  * caller shouldn't need to know that small detail.
 170  */
 171 static void __iomem *__ioremap_caller(resource_size_t phys_addr,
 172                 unsigned long size, unsigned long prot_val, void *caller)
 173 {
 174         unsigned long pfn, offset, vaddr;
 175         resource_size_t last_addr;
 176         const resource_size_t unaligned_phys_addr = phys_addr;
 177         const unsigned long unaligned_size = size;
 178         struct vm_struct *area;
 179         unsigned long new_prot_val;
 180         pgprot_t prot;
 181         int retval;
 182         void __iomem *ret_addr;
 183
 184         /* Don't allow wraparound or zero size */
 185         last_addr = phys_addr + size - 1;
 186         if (!size || last_addr < phys_addr)
 187                 return NULL;
 188
 189         if (!phys_addr_valid(phys_addr)) {
 190                 printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
 191                        (unsigned long long)phys_addr);
 192                 WARN_ON_ONCE(1);
 193                 return NULL;
 194         }
 195
 196         /*
 197          * Don't remap the low PCI/ISA area, it's always mapped..
 198          */
 199         if (is_ISA_range(phys_addr, last_addr))
 200                 return (__force void __iomem *)phys_to_virt(phys_addr);
 201
 202         /*
 203          * Check if the request spans more than any BAR in the iomem resource
 204          * tree.
 205          */
 206         WARN_ONCE(iomem_map_sanity_check(phys_addr, size),
 207                   KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
 208
 209         /*
 210          * Don't allow anybody to remap normal RAM that we're using..
 211          */
 212         for (pfn = phys_addr >> PAGE_SHIFT;
 213                                 (pfn << PAGE_SHIFT) < (last_addr & PAGE_MASK);
 214                                 pfn++) {
 215
 216                 int is_ram = page_is_ram(pfn);
 217
 218                 if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
 219                         return NULL;
 220                 WARN_ON_ONCE(is_ram);
 221         }
 222
 223         /*
 224          * Mappings have to be page-aligned
 225          */
 226         offset = phys_addr & ~PAGE_MASK;
 227         phys_addr &= PAGE_MASK;
 228         size = PAGE_ALIGN(last_addr+1) - phys_addr;
 229
 230         retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
 231                                                 prot_val, &new_prot_val);
 232         if (retval) {
 233                 pr_debug("Warning: reserve_memtype returned %d\n", retval);
 234                 return NULL;
 235         }
 236
 237         if (prot_val != new_prot_val) {
 238                 /*
 239                  * Do not fallback to certain memory types with certain
 240                  * requested type:
 241                  * - request is uc-, return cannot be write-back
 242                  * - request is uc-, return cannot be write-combine
 243                  * - request is write-combine, return cannot be write-back
 244                  */
 245                 if ((prot_val == _PAGE_CACHE_UC_MINUS &&
 246                      (new_prot_val == _PAGE_CACHE_WB ||
 247                       new_prot_val == _PAGE_CACHE_WC)) ||
 248                     (prot_val == _PAGE_CACHE_WC &&
 249                      new_prot_val == _PAGE_CACHE_WB)) {
 250                         pr_debug(
 251                 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
 252                                 (unsigned long long)phys_addr,
 253                                 (unsigned long long)(phys_addr + size),
 254                                 prot_val, new_prot_val);
 255                         free_memtype(phys_addr, phys_addr + size);
 256                         return NULL;
 257                 }
 258                 prot_val = new_prot_val;
 259         }
 260
 261         switch (prot_val) {
 262         case _PAGE_CACHE_UC:
 263         default:
 264                 prot = PAGE_KERNEL_IO_NOCACHE;
 265                 break;
 266         case _PAGE_CACHE_UC_MINUS:
 267                 prot = PAGE_KERNEL_IO_UC_MINUS;
 268                 break;
 269         case _PAGE_CACHE_WC:
 270                 prot = PAGE_KERNEL_IO_WC;
 271                 break;
 272         case _PAGE_CACHE_WB:
 273                 prot = PAGE_KERNEL_IO;
 274                 break;
 275         }
 276
 277         /*
 278          * Ok, go for it..
 279          */
 280         area = get_vm_area_caller(size, VM_IOREMAP, caller);
 281         if (!area)
 282                 return NULL;
 283         area->phys_addr = phys_addr;
 284         vaddr = (unsigned long) area->addr;
 285         if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
 286                 free_memtype(phys_addr, phys_addr + size);
 287                 free_vm_area(area);
 288                 return NULL;
 289         }
 290
 291         if (ioremap_change_attr(vaddr, size, prot_val) < 0) {
 292                 free_memtype(phys_addr, phys_addr + size);
 293                 vunmap(area->addr);
 294                 return NULL;
 295         }
 296
 297         ret_addr = (void __iomem *) (vaddr + offset);
 298         mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
 299
 300         return ret_addr;
 301 }
 302
 303 /**
 304  * ioremap_nocache     -   map bus memory into CPU space
 305  * @offset:    bus address of the memory
 306  * @size:      size of the resource to map
 307  *
 308  * ioremap_nocache performs a platform specific sequence of operations to
 309  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 310  * writew/writel functions and the other mmio helpers. The returned
 311  * address is not guaranteed to be usable directly as a virtual
 312  * address.
 313  *
 314  * This version of ioremap ensures that the memory is marked uncachable
 315  * on the CPU as well as honouring existing caching rules from things like
 316  * the PCI bus. Note that there are other caches and buffers on many
 317  * busses. In particular driver authors should read up on PCI writes
 318  *
 319  * It's useful if some control registers are in such an area and
 320  * write combining or read caching is not desirable:
 321  *
 322  * Must be freed with iounmap.
 323  */
 324 void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
 325 {
 326         /*
 327          * Ideally, this should be:
 328          *      pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
 329          *
 330          * Till we fix all X drivers to use ioremap_wc(), we will use
 331          * UC MINUS.
 332          */
 333         unsigned long val = _PAGE_CACHE_UC_MINUS;
 334
 335         return __ioremap_caller(phys_addr, size, val,
 336                                 __builtin_return_address(0));
 337 }
 338 EXPORT_SYMBOL(ioremap_nocache);
 339
 340 /**
 341  * ioremap_wc   -       map memory into CPU space write combined
 342  * @offset:     bus address of the memory
 343  * @size:       size of the resource to map
 344  *
 345  * This version of ioremap ensures that the memory is marked write combining.
 346  * Write combining allows faster writes to some hardware devices.
 347  *
 348  * Must be freed with iounmap.
 349  */
 350 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
 351 {
 352         if (pat_enabled)
 353                 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
 354                                         __builtin_return_address(0));
 355         else
 356                 return ioremap_nocache(phys_addr, size);
 357 }
 358 EXPORT_SYMBOL(ioremap_wc);
 359
 360 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
 361 {
 362         return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
 363                                 __builtin_return_address(0));
 364 }
 365 EXPORT_SYMBOL(ioremap_cache);
 366
 367 static void __iomem *ioremap_default(resource_size_t phys_addr,
 368                                         unsigned long size)
 369 {
 370         unsigned long flags;
 371         void __iomem *ret;
 372         int err;
 373
 374         /*
 375          * - WB for WB-able memory and no other conflicting mappings
 376          * - UC_MINUS for non-WB-able memory with no other conflicting mappings
 377          * - Inherit from confliting mappings otherwise
 378          */
 379         err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags);
 380         if (err < 0)
 381                 return NULL;
 382
 383         ret = __ioremap_caller(phys_addr, size, flags,
 384                                __builtin_return_address(0));
 385
 386         free_memtype(phys_addr, phys_addr + size);
 387         return ret;
 388 }
 389
 390 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
 391                                 unsigned long prot_val)
 392 {
 393         return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
 394                                 __builtin_return_address(0));
 395 }
 396 EXPORT_SYMBOL(ioremap_prot);
 397
 398 /**
 399  * iounmap - Free a IO remapping
 400  * @addr: virtual address from ioremap_*
 401  *
 402  * Caller must ensure there is only one unmapping for the same pointer.
 403  */
 404 void iounmap(volatile void __iomem *addr)
 405 {
 406         struct vm_struct *p, *o;
 407
 408         if ((void __force *)addr <= high_memory)
 409                 return;
 410
 411         /*
 412          * __ioremap special-cases the PCI/ISA range by not instantiating a
 413          * vm_area and by simply returning an address into the kernel mapping
 414          * of ISA space.   So handle that here.
 415          */
 416         if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
 417             (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
 418                 return;
 419
 420         addr = (volatile void __iomem *)
 421                 (PAGE_MASK & (unsigned long __force)addr);
 422
 423         mmiotrace_iounmap(addr);
 424
 425         /* Use the vm area unlocked, assuming the caller
 426            ensures there isn't another iounmap for the same address
 427            in parallel. Reuse of the virtual address is prevented by
 428            leaving it in the global lists until we're done with it.
 429            cpa takes care of the direct mappings. */
 430         read_lock(&vmlist_lock);
 431         for (p = vmlist; p; p = p->next) {
 432                 if (p->addr == (void __force *)addr)
 433                         break;
 434         }
 435         read_unlock(&vmlist_lock);
 436
 437         if (!p) {
 438                 printk(KERN_ERR "iounmap: bad address %p\n", addr);
 439                 dump_stack();
 440                 return;
 441         }
 442
 443         free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
 444
 445         /* Finally remove it */
 446         o = remove_vm_area((void __force *)addr);
 447         BUG_ON(p != o || o == NULL);
 448         kfree(p);
 449 }
 450 EXPORT_SYMBOL(iounmap);
 451
 452 /*
 453  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
 454  * access
 455  */
 456 void *xlate_dev_mem_ptr(unsigned long phys)
 457 {
 458         void *addr;
 459         unsigned long start = phys & PAGE_MASK;
 460
 461         /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
 462         if (page_is_ram(start >> PAGE_SHIFT))
 463                 return __va(phys);
 464
 465         addr = (void __force *)ioremap_default(start, PAGE_SIZE);
 466         if (addr)
 467                 addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
 468
 469         return addr;
 470 }
 471
 472 void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
 473 {
 474         if (page_is_ram(phys >> PAGE_SHIFT))
 475                 return;
 476
 477         iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
 478         return;
 479 }
 480
 481 static int __initdata early_ioremap_debug;
 482
 483 static int __init early_ioremap_debug_setup(char *str)
 484 {
 485         early_ioremap_debug = 1;
 486
 487         return 0;
 488 }
 489 early_param("early_ioremap_debug", early_ioremap_debug_setup);
 490
 491 static __initdata int after_paging_init;
 492 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
 493
 494 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
 495 {
 496         /* Don't assume we're using swapper_pg_dir at this point */
 497         pgd_t *base = __va(read_cr3());
 498         pgd_t *pgd = &base[pgd_index(addr)];
 499         pud_t *pud = pud_offset(pgd, addr);
 500         pmd_t *pmd = pmd_offset(pud, addr);
 501
 502         return pmd;
 503 }
 504
 505 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
 506 {
 507         return &bm_pte[pte_index(addr)];
 508 }
 509
 510 void __init early_ioremap_init(void)
 511 {
 512         pmd_t *pmd;
 513
 514         if (early_ioremap_debug)
 515                 printk(KERN_INFO "early_ioremap_init()\n");
 516
 517         pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
 518         memset(bm_pte, 0, sizeof(bm_pte));
 519         pmd_populate_kernel(&init_mm, pmd, bm_pte);
 520
 521         /*
 522          * The boot-ioremap range spans multiple pmds, for which
 523          * we are not prepared:
 524          */
 525         if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
 526                 WARN_ON(1);
 527                 printk(KERN_WARNING "pmd %p != %p\n",
 528                        pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
 529                 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
 530                         fix_to_virt(FIX_BTMAP_BEGIN));
 531                 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
 532                         fix_to_virt(FIX_BTMAP_END));
 533
 534                 printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
 535                 printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
 536                        FIX_BTMAP_BEGIN);
 537         }
 538 }
 539
 540 void __init early_ioremap_reset(void)
 541 {
 542         after_paging_init = 1;
 543 }
 544
 545 static void __init __early_set_fixmap(enum fixed_addresses idx,
 546                                    unsigned long phys, pgprot_t flags)
 547 {
 548         unsigned long addr = __fix_to_virt(idx);
 549         pte_t *pte;
 550
 551         if (idx >= __end_of_fixed_addresses) {
 552                 BUG();
 553                 return;
 554         }
 555         pte = early_ioremap_pte(addr);
 556
 557         if (pgprot_val(flags))
 558                 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 559         else
 560                 pte_clear(&init_mm, addr, pte);
 561         __flush_tlb_one(addr);
 562 }
 563
 564 static inline void __init early_set_fixmap(enum fixed_addresses idx,
 565                                            unsigned long phys, pgprot_t prot)
 566 {
 567         if (after_paging_init)
 568                 __set_fixmap(idx, phys, prot);
 569         else
 570                 __early_set_fixmap(idx, phys, prot);
 571 }
 572
 573 static inline void __init early_clear_fixmap(enum fixed_addresses idx)
 574 {
 575         if (after_paging_init)
 576                 clear_fixmap(idx);
 577         else
 578                 __early_set_fixmap(idx, 0, __pgprot(0));
 579 }
 580
 581 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
 582 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
 583 static int __init check_early_ioremap_leak(void)
 584 {
 585         int count = 0;
 586         int i;
 587
 588         for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
 589                 if (prev_map[i])
 590                         count++;
 591
 592         if (!count)
 593                 return 0;
 594         WARN(1, KERN_WARNING
 595                "Debug warning: early ioremap leak of %d areas detected.\n",
 596                 count);
 597         printk(KERN_WARNING
 598                 "please boot with early_ioremap_debug and report the dmesg.\n");
 599
 600         return 1;
 601 }
 602 late_initcall(check_early_ioremap_leak);
 603
 604 static void __init __iomem *__early_ioremap(unsigned long phys_addr, unsigned long size, pgprot_t prot)
 605 {
 606         unsigned long offset, last_addr;
 607         unsigned int nrpages;
 608         enum fixed_addresses idx0, idx;
 609         int i, slot;
 610
 611         WARN_ON(system_state != SYSTEM_BOOTING);
 612
 613         slot = -1;
 614         for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
 615                 if (!prev_map[i]) {
 616                         slot = i;
 617                         break;
 618                 }
 619         }
 620
 621         if (slot < 0) {
 622                 printk(KERN_INFO "early_iomap(%08lx, %08lx) not found slot\n",
 623                          phys_addr, size);
 624                 WARN_ON(1);
 625                 return NULL;
 626         }
 627
 628         if (early_ioremap_debug) {
 629                 printk(KERN_INFO "early_ioremap(%08lx, %08lx) [%d] => ",
 630                        phys_addr, size, slot);
 631                 dump_stack();
 632         }
 633
 634         /* Don't allow wraparound or zero size */
 635         last_addr = phys_addr + size - 1;
 636         if (!size || last_addr < phys_addr) {
 637                 WARN_ON(1);
 638                 return NULL;
 639         }
 640
 641         prev_size[slot] = size;
 642         /*
 643          * Mappings have to be page-aligned
 644          */
 645         offset = phys_addr & ~PAGE_MASK;
 646         phys_addr &= PAGE_MASK;
 647         size = PAGE_ALIGN(last_addr + 1) - phys_addr;
 648
 649         /*
 650          * Mappings have to fit in the FIX_BTMAP area.
 651          */
 652         nrpages = size >> PAGE_SHIFT;
 653         if (nrpages > NR_FIX_BTMAPS) {
 654                 WARN_ON(1);
 655                 return NULL;
 656         }
 657
 658         /*
 659          * Ok, go for it..
 660          */
 661         idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 662         idx = idx0;
 663         while (nrpages > 0) {
 664                 early_set_fixmap(idx, phys_addr, prot);
 665                 phys_addr += PAGE_SIZE;
 666                 --idx;
 667                 --nrpages;
 668         }
 669         if (early_ioremap_debug)
 670                 printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
 671
 672         prev_map[slot] = (void __iomem *)(offset + fix_to_virt(idx0));
 673         return prev_map[slot];
 674 }
 675
 676 /* Remap an IO device */
 677 void __init __iomem *early_ioremap(unsigned long phys_addr, unsigned long size)
 678 {
 679         return __early_ioremap(phys_addr, size, PAGE_KERNEL_IO);
 680 }
 681
 682 /* Remap memory */
 683 void __init __iomem *early_memremap(unsigned long phys_addr, unsigned long size)
 684 {
 685         return __early_ioremap(phys_addr, size, PAGE_KERNEL);
 686 }
 687
 688 void __init early_iounmap(void __iomem *addr, unsigned long size)
 689 {
 690         unsigned long virt_addr;
 691         unsigned long offset;
 692         unsigned int nrpages;
 693         enum fixed_addresses idx;
 694         int i, slot;
 695
 696         slot = -1;
 697         for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
 698                 if (prev_map[i] == addr) {
 699                         slot = i;
 700                         break;
 701                 }
 702         }
 703
 704         if (slot < 0) {
 705                 printk(KERN_INFO "early_iounmap(%p, %08lx) not found slot\n",
 706                          addr, size);
 707                 WARN_ON(1);
 708                 return;
 709         }
 710
 711         if (prev_size[slot] != size) {
 712                 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
 713                          addr, size, slot, prev_size[slot]);
 714                 WARN_ON(1);
 715                 return;
 716         }
 717
 718         if (early_ioremap_debug) {
 719                 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
 720                        size, slot);
 721                 dump_stack();
 722         }
 723
 724         virt_addr = (unsigned long)addr;
 725         if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
 726                 WARN_ON(1);
 727                 return;
 728         }
 729         offset = virt_addr & ~PAGE_MASK;
 730         nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
 731
 732         idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 733         while (nrpages > 0) {
 734                 early_clear_fixmap(idx);
 735                 --idx;
 736                 --nrpages;
 737         }
 738         prev_map[slot] = NULL;
 739 }
 740
 741 void __this_fixmap_does_not_exist(void)
 742 {
 743         WARN_ON(1);
 744 }