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 static inline int phys_addr_valid(resource_size_t addr)
  26 {
  27 #ifdef CONFIG_PHYS_ADDR_T_64BIT
  28         return !(addr >> boot_cpu_data.x86_phys_bits);
  29 #else
  30         return 1;
  31 #endif
  32 }
  33
  34 #ifdef CONFIG_X86_64
  35
  36 unsigned long __phys_addr(unsigned long x)
  37 {
  38         if (x >= __START_KERNEL_map) {
  39                 x -= __START_KERNEL_map;
  40                 VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
  41                 x += phys_base;
  42         } else {
  43                 VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  44                 x -= PAGE_OFFSET;
  45                 VIRTUAL_BUG_ON(!phys_addr_valid(x));
  46         }
  47         return x;
  48 }
  49 EXPORT_SYMBOL(__phys_addr);
  50
  51 bool __virt_addr_valid(unsigned long x)
  52 {
  53         if (x >= __START_KERNEL_map) {
  54                 x -= __START_KERNEL_map;
  55                 if (x >= KERNEL_IMAGE_SIZE)
  56                         return false;
  57                 x += phys_base;
  58         } else {
  59                 if (x < PAGE_OFFSET)
  60                         return false;
  61                 x -= PAGE_OFFSET;
  62                 if (!phys_addr_valid(x))
  63                         return false;
  64         }
  65
  66         return pfn_valid(x >> PAGE_SHIFT);
  67 }
  68 EXPORT_SYMBOL(__virt_addr_valid);
  69
  70 #else
  71
  72 #ifdef CONFIG_DEBUG_VIRTUAL
  73 unsigned long __phys_addr(unsigned long x)
  74 {
  75         /* VMALLOC_* aren't constants  */
  76         VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  77         VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
  78         return x - PAGE_OFFSET;
  79 }
  80 EXPORT_SYMBOL(__phys_addr);
  81 #endif
  82
  83 bool __virt_addr_valid(unsigned long x)
  84 {
  85         if (x < PAGE_OFFSET)
  86                 return false;
  87         if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
  88                 return false;
  89         if (x >= FIXADDR_START)
  90                 return false;
  91         return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
  92 }
  93 EXPORT_SYMBOL(__virt_addr_valid);
  94
  95 #endif
  96
  97 int page_is_ram(unsigned long pagenr)
  98 {
  99         resource_size_t addr, end;
 100         int i;
 101
 102         /*
 103          * A special case is the first 4Kb of memory;
 104          * This is a BIOS owned area, not kernel ram, but generally
 105          * not listed as such in the E820 table.
 106          */
 107         if (pagenr == 0)
 108                 return 0;
 109
 110         /*
 111          * Second special case: Some BIOSen report the PC BIOS
 112          * area (640->1Mb) as ram even though it is not.
 113          */
 114         if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
 115                     pagenr < (BIOS_END >> PAGE_SHIFT))
 116                 return 0;
 117
 118         for (i = 0; i < e820.nr_map; i++) {
 119                 /*
 120                  * Not usable memory:
 121                  */
 122                 if (e820.map[i].type != E820_RAM)
 123                         continue;
 124                 addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
 125                 end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
 126
 127
 128                 if ((pagenr >= addr) && (pagenr < end))
 129                         return 1;
 130         }
 131         return 0;
 132 }
 133
 134 /*
 135  * Fix up the linear direct mapping of the kernel to avoid cache attribute
 136  * conflicts.
 137  */
 138 int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 139                                unsigned long prot_val)
 140 {
 141         unsigned long nrpages = size >> PAGE_SHIFT;
 142         int err;
 143
 144         switch (prot_val) {
 145         case _PAGE_CACHE_UC:
 146         default:
 147                 err = _set_memory_uc(vaddr, nrpages);
 148                 break;
 149         case _PAGE_CACHE_WC:
 150                 err = _set_memory_wc(vaddr, nrpages);
 151                 break;
 152         case _PAGE_CACHE_WB:
 153                 err = _set_memory_wb(vaddr, nrpages);
 154                 break;
 155         }
 156
 157         return err;
 158 }
 159
 160 /*
 161  * Remap an arbitrary physical address space into the kernel virtual
 162  * address space. Needed when the kernel wants to access high addresses
 163  * directly.
 164  *
 165  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 166  * have to convert them into an offset in a page-aligned mapping, but the
 167  * caller shouldn't need to know that small detail.
 168  */
 169 static void __iomem *__ioremap_caller(resource_size_t phys_addr,
 170                 unsigned long size, unsigned long prot_val, void *caller)
 171 {
 172         unsigned long pfn, offset, vaddr;
 173         resource_size_t last_addr;
 174         const resource_size_t unaligned_phys_addr = phys_addr;
 175         const unsigned long unaligned_size = size;
 176         struct vm_struct *area;
 177         unsigned long new_prot_val;
 178         pgprot_t prot;
 179         int retval;
 180         void __iomem *ret_addr;
 181
 182         /* Don't allow wraparound or zero size */
 183         last_addr = phys_addr + size - 1;
 184         if (!size || last_addr < phys_addr)
 185                 return NULL;
 186
 187         if (!phys_addr_valid(phys_addr)) {
 188                 printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
 189                        (unsigned long long)phys_addr);
 190                 WARN_ON_ONCE(1);
 191                 return NULL;
 192         }
 193
 194         /*
 195          * Don't remap the low PCI/ISA area, it's always mapped..
 196          */
 197         if (is_ISA_range(phys_addr, last_addr))
 198                 return (__force void __iomem *)phys_to_virt(phys_addr);
 199
 200         /*
 201          * Check if the request spans more than any BAR in the iomem resource
 202          * tree.
 203          */
 204         WARN_ONCE(iomem_map_sanity_check(phys_addr, size),
 205                   KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
 206
 207         /*
 208          * Don't allow anybody to remap normal RAM that we're using..
 209          */
 210         for (pfn = phys_addr >> PAGE_SHIFT;
 211                                 (pfn << PAGE_SHIFT) < (last_addr & PAGE_MASK);
 212                                 pfn++) {
 213
 214                 int is_ram = page_is_ram(pfn);
 215
 216                 if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
 217                         return NULL;
 218                 WARN_ON_ONCE(is_ram);
 219         }
 220
 221         /*
 222          * Mappings have to be page-aligned
 223          */
 224         offset = phys_addr & ~PAGE_MASK;
 225         phys_addr &= PAGE_MASK;
 226         size = PAGE_ALIGN(last_addr+1) - phys_addr;
 227
 228         retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
 229                                                 prot_val, &new_prot_val);
 230         if (retval) {
 231                 printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
 232                 return NULL;
 233         }
 234
 235         if (prot_val != new_prot_val) {
 236                 if (!is_new_memtype_allowed(phys_addr, size,
 237                                             prot_val, new_prot_val)) {
 238                         printk(KERN_ERR
 239                 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
 240                                 (unsigned long long)phys_addr,
 241                                 (unsigned long long)(phys_addr + size),
 242                                 prot_val, new_prot_val);
 243                         free_memtype(phys_addr, phys_addr + size);
 244                         return NULL;
 245                 }
 246                 prot_val = new_prot_val;
 247         }
 248
 249         switch (prot_val) {
 250         case _PAGE_CACHE_UC:
 251         default:
 252                 prot = PAGE_KERNEL_IO_NOCACHE;
 253                 break;
 254         case _PAGE_CACHE_UC_MINUS:
 255                 prot = PAGE_KERNEL_IO_UC_MINUS;
 256                 break;
 257         case _PAGE_CACHE_WC:
 258                 prot = PAGE_KERNEL_IO_WC;
 259                 break;
 260         case _PAGE_CACHE_WB:
 261                 prot = PAGE_KERNEL_IO;
 262                 break;
 263         }
 264
 265         /*
 266          * Ok, go for it..
 267          */
 268         area = get_vm_area_caller(size, VM_IOREMAP, caller);
 269         if (!area)
 270                 return NULL;
 271         area->phys_addr = phys_addr;
 272         vaddr = (unsigned long) area->addr;
 273
 274         if (kernel_map_sync_memtype(phys_addr, size, prot_val)) {
 275                 free_memtype(phys_addr, phys_addr + size);
 276                 free_vm_area(area);
 277                 return NULL;
 278         }
 279
 280         if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
 281                 free_memtype(phys_addr, phys_addr + size);
 282                 free_vm_area(area);
 283                 return NULL;
 284         }
 285
 286         ret_addr = (void __iomem *) (vaddr + offset);
 287         mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
 288
 289         return ret_addr;
 290 }
 291
 292 /**
 293  * ioremap_nocache     -   map bus memory into CPU space
 294  * @offset:    bus address of the memory
 295  * @size:      size of the resource to map
 296  *
 297  * ioremap_nocache performs a platform specific sequence of operations to
 298  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 299  * writew/writel functions and the other mmio helpers. The returned
 300  * address is not guaranteed to be usable directly as a virtual
 301  * address.
 302  *
 303  * This version of ioremap ensures that the memory is marked uncachable
 304  * on the CPU as well as honouring existing caching rules from things like
 305  * the PCI bus. Note that there are other caches and buffers on many
 306  * busses. In particular driver authors should read up on PCI writes
 307  *
 308  * It's useful if some control registers are in such an area and
 309  * write combining or read caching is not desirable:
 310  *
 311  * Must be freed with iounmap.
 312  */
 313 void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
 314 {
 315         /*
 316          * Ideally, this should be:
 317          *      pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
 318          *
 319          * Till we fix all X drivers to use ioremap_wc(), we will use
 320          * UC MINUS.
 321          */
 322         unsigned long val = _PAGE_CACHE_UC_MINUS;
 323
 324         return __ioremap_caller(phys_addr, size, val,
 325                                 __builtin_return_address(0));
 326 }
 327 EXPORT_SYMBOL(ioremap_nocache);
 328
 329 /**
 330  * ioremap_wc   -       map memory into CPU space write combined
 331  * @offset:     bus address of the memory
 332  * @size:       size of the resource to map
 333  *
 334  * This version of ioremap ensures that the memory is marked write combining.
 335  * Write combining allows faster writes to some hardware devices.
 336  *
 337  * Must be freed with iounmap.
 338  */
 339 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
 340 {
 341         if (pat_enabled)
 342                 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
 343                                         __builtin_return_address(0));
 344         else
 345                 return ioremap_nocache(phys_addr, size);
 346 }
 347 EXPORT_SYMBOL(ioremap_wc);
 348
 349 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
 350 {
 351         return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
 352                                 __builtin_return_address(0));
 353 }
 354 EXPORT_SYMBOL(ioremap_cache);
 355
 356 static void __iomem *ioremap_default(resource_size_t phys_addr,
 357                                         unsigned long size)
 358 {
 359         unsigned long flags;
 360         void __iomem *ret;
 361         int err;
 362
 363         /*
 364          * - WB for WB-able memory and no other conflicting mappings
 365          * - UC_MINUS for non-WB-able memory with no other conflicting mappings
 366          * - Inherit from confliting mappings otherwise
 367          */
 368         err = reserve_memtype(phys_addr, phys_addr + size,
 369                                 _PAGE_CACHE_WB, &flags);
 370         if (err < 0)
 371                 return NULL;
 372
 373         ret = __ioremap_caller(phys_addr, size, flags,
 374                                __builtin_return_address(0));
 375
 376         free_memtype(phys_addr, phys_addr + size);
 377         return ret;
 378 }
 379
 380 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
 381                                 unsigned long prot_val)
 382 {
 383         return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
 384                                 __builtin_return_address(0));
 385 }
 386 EXPORT_SYMBOL(ioremap_prot);
 387
 388 /**
 389  * iounmap - Free a IO remapping
 390  * @addr: virtual address from ioremap_*
 391  *
 392  * Caller must ensure there is only one unmapping for the same pointer.
 393  */
 394 void iounmap(volatile void __iomem *addr)
 395 {
 396         struct vm_struct *p, *o;
 397
 398         if ((void __force *)addr <= high_memory)
 399                 return;
 400
 401         /*
 402          * __ioremap special-cases the PCI/ISA range by not instantiating a
 403          * vm_area and by simply returning an address into the kernel mapping
 404          * of ISA space.   So handle that here.
 405          */
 406         if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
 407             (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
 408                 return;
 409
 410         addr = (volatile void __iomem *)
 411                 (PAGE_MASK & (unsigned long __force)addr);
 412
 413         mmiotrace_iounmap(addr);
 414
 415         /* Use the vm area unlocked, assuming the caller
 416            ensures there isn't another iounmap for the same address
 417            in parallel. Reuse of the virtual address is prevented by
 418            leaving it in the global lists until we're done with it.
 419            cpa takes care of the direct mappings. */
 420         read_lock(&vmlist_lock);
 421         for (p = vmlist; p; p = p->next) {
 422                 if (p->addr == (void __force *)addr)
 423                         break;
 424         }
 425         read_unlock(&vmlist_lock);
 426
 427         if (!p) {
 428                 printk(KERN_ERR "iounmap: bad address %p\n", addr);
 429                 dump_stack();
 430                 return;
 431         }
 432
 433         free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
 434
 435         /* Finally remove it */
 436         o = remove_vm_area((void __force *)addr);
 437         BUG_ON(p != o || o == NULL);
 438         kfree(p);
 439 }
 440 EXPORT_SYMBOL(iounmap);
 441
 442 /*
 443  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
 444  * access
 445  */
 446 void *xlate_dev_mem_ptr(unsigned long phys)
 447 {
 448         void *addr;
 449         unsigned long start = phys & PAGE_MASK;
 450
 451         /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
 452         if (page_is_ram(start >> PAGE_SHIFT))
 453                 return __va(phys);
 454
 455         addr = (void __force *)ioremap_default(start, PAGE_SIZE);
 456         if (addr)
 457                 addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
 458
 459         return addr;
 460 }
 461
 462 void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
 463 {
 464         if (page_is_ram(phys >> PAGE_SHIFT))
 465                 return;
 466
 467         iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
 468         return;
 469 }
 470
 471 static int __initdata early_ioremap_debug;
 472
 473 static int __init early_ioremap_debug_setup(char *str)
 474 {
 475         early_ioremap_debug = 1;
 476
 477         return 0;
 478 }
 479 early_param("early_ioremap_debug", early_ioremap_debug_setup);
 480
 481 static __initdata int after_paging_init;
 482 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
 483
 484 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
 485 {
 486         /* Don't assume we're using swapper_pg_dir at this point */
 487         pgd_t *base = __va(read_cr3());
 488         pgd_t *pgd = &base[pgd_index(addr)];
 489         pud_t *pud = pud_offset(pgd, addr);
 490         pmd_t *pmd = pmd_offset(pud, addr);
 491
 492         return pmd;
 493 }
 494
 495 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
 496 {
 497         return &bm_pte[pte_index(addr)];
 498 }
 499
 500 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
 501
 502 void __init early_ioremap_init(void)
 503 {
 504         pmd_t *pmd;
 505         int i;
 506
 507         if (early_ioremap_debug)
 508                 printk(KERN_INFO "early_ioremap_init()\n");
 509
 510         for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
 511                 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
 512
 513         pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
 514         memset(bm_pte, 0, sizeof(bm_pte));
 515         pmd_populate_kernel(&init_mm, pmd, bm_pte);
 516
 517         /*
 518          * The boot-ioremap range spans multiple pmds, for which
 519          * we are not prepared:
 520          */
 521         if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
 522                 WARN_ON(1);
 523                 printk(KERN_WARNING "pmd %p != %p\n",
 524                        pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
 525                 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
 526                         fix_to_virt(FIX_BTMAP_BEGIN));
 527                 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
 528                         fix_to_virt(FIX_BTMAP_END));
 529
 530                 printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
 531                 printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
 532                        FIX_BTMAP_BEGIN);
 533         }
 534 }
 535
 536 void __init early_ioremap_reset(void)
 537 {
 538         after_paging_init = 1;
 539 }
 540
 541 static void __init __early_set_fixmap(enum fixed_addresses idx,
 542                                       phys_addr_t phys, pgprot_t flags)
 543 {
 544         unsigned long addr = __fix_to_virt(idx);
 545         pte_t *pte;
 546
 547         if (idx >= __end_of_fixed_addresses) {
 548                 BUG();
 549                 return;
 550         }
 551         pte = early_ioremap_pte(addr);
 552
 553         if (pgprot_val(flags))
 554                 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 555         else
 556                 pte_clear(&init_mm, addr, pte);
 557         __flush_tlb_one(addr);
 558 }
 559
 560 static inline void __init early_set_fixmap(enum fixed_addresses idx,
 561                                            phys_addr_t phys, pgprot_t prot)
 562 {
 563         if (after_paging_init)
 564                 __set_fixmap(idx, phys, prot);
 565         else
 566                 __early_set_fixmap(idx, phys, prot);
 567 }
 568
 569 static inline void __init early_clear_fixmap(enum fixed_addresses idx)
 570 {
 571         if (after_paging_init)
 572                 clear_fixmap(idx);
 573         else
 574                 __early_set_fixmap(idx, 0, __pgprot(0));
 575 }
 576
 577 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
 578 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
 579
 580 static int __init check_early_ioremap_leak(void)
 581 {
 582         int count = 0;
 583         int i;
 584
 585         for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
 586                 if (prev_map[i])
 587                         count++;
 588
 589         if (!count)
 590                 return 0;
 591         WARN(1, KERN_WARNING
 592                "Debug warning: early ioremap leak of %d areas detected.\n",
 593                 count);
 594         printk(KERN_WARNING
 595                 "please boot with early_ioremap_debug and report the dmesg.\n");
 596
 597         return 1;
 598 }
 599 late_initcall(check_early_ioremap_leak);
 600
 601 static void __init __iomem *
 602 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
 603 {
 604         unsigned long offset;
 605         resource_size_t last_addr;
 606         unsigned int nrpages;
 607         enum fixed_addresses idx0, idx;
 608         int i, slot;
 609
 610         WARN_ON(system_state != SYSTEM_BOOTING);
 611
 612         slot = -1;
 613         for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
 614                 if (!prev_map[i]) {
 615                         slot = i;
 616                         break;
 617                 }
 618         }
 619
 620         if (slot < 0) {
 621                 printk(KERN_INFO "early_iomap(%08llx, %08lx) not found slot\n",
 622                          (u64)phys_addr, size);
 623                 WARN_ON(1);
 624                 return NULL;
 625         }
 626
 627         if (early_ioremap_debug) {
 628                 printk(KERN_INFO "early_ioremap(%08llx, %08lx) [%d] => ",
 629                        (u64)phys_addr, size, slot);
 630                 dump_stack();
 631         }
 632
 633         /* Don't allow wraparound or zero size */
 634         last_addr = phys_addr + size - 1;
 635         if (!size || last_addr < phys_addr) {
 636                 WARN_ON(1);
 637                 return NULL;
 638         }
 639
 640         prev_size[slot] = size;
 641         /*
 642          * Mappings have to be page-aligned
 643          */
 644         offset = phys_addr & ~PAGE_MASK;
 645         phys_addr &= PAGE_MASK;
 646         size = PAGE_ALIGN(last_addr + 1) - phys_addr;
 647
 648         /*
 649          * Mappings have to fit in the FIX_BTMAP area.
 650          */
 651         nrpages = size >> PAGE_SHIFT;
 652         if (nrpages > NR_FIX_BTMAPS) {
 653                 WARN_ON(1);
 654                 return NULL;
 655         }
 656
 657         /*
 658          * Ok, go for it..
 659          */
 660         idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 661         idx = idx0;
 662         while (nrpages > 0) {
 663                 early_set_fixmap(idx, phys_addr, prot);
 664                 phys_addr += PAGE_SIZE;
 665                 --idx;
 666                 --nrpages;
 667         }
 668         if (early_ioremap_debug)
 669                 printk(KERN_CONT "%08lx + %08lx\n", offset, slot_virt[slot]);
 670
 671         prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
 672         return prev_map[slot];
 673 }
 674
 675 /* Remap an IO device */
 676 void __init __iomem *
 677 early_ioremap(resource_size_t 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 *
 684 early_memremap(resource_size_t phys_addr, unsigned long size)
 685 {
 686         return __early_ioremap(phys_addr, size, PAGE_KERNEL);
 687 }
 688
 689 void __init early_iounmap(void __iomem *addr, unsigned long size)
 690 {
 691         unsigned long virt_addr;
 692         unsigned long offset;
 693         unsigned int nrpages;
 694         enum fixed_addresses idx;
 695         int i, slot;
 696
 697         slot = -1;
 698         for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
 699                 if (prev_map[i] == addr) {
 700                         slot = i;
 701                         break;
 702                 }
 703         }
 704
 705         if (slot < 0) {
 706                 printk(KERN_INFO "early_iounmap(%p, %08lx) not found slot\n",
 707                          addr, size);
 708                 WARN_ON(1);
 709                 return;
 710         }
 711
 712         if (prev_size[slot] != size) {
 713                 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
 714                          addr, size, slot, prev_size[slot]);
 715                 WARN_ON(1);
 716                 return;
 717         }
 718
 719         if (early_ioremap_debug) {
 720                 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
 721                        size, slot);
 722                 dump_stack();
 723         }
 724
 725         virt_addr = (unsigned long)addr;
 726         if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
 727                 WARN_ON(1);
 728                 return;
 729         }
 730         offset = virt_addr & ~PAGE_MASK;
 731         nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
 732
 733         idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 734         while (nrpages > 0) {
 735                 early_clear_fixmap(idx);
 736                 --idx;
 737                 --nrpages;
 738         }
 739         prev_map[slot] = NULL;
 740 }