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