Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * (C) Copyright 1995 1996 Linus Torvalds |
| 7 | * (C) Copyright 2001, 2002 Ralf Baechle |
| 8 | */ |
| 9 | #include <linux/module.h> |
| 10 | #include <asm/addrspace.h> |
| 11 | #include <asm/byteorder.h> |
| 12 | |
| 13 | #include <linux/vmalloc.h> |
| 14 | #include <asm/cacheflush.h> |
| 15 | #include <asm/io.h> |
| 16 | #include <asm/tlbflush.h> |
| 17 | |
| 18 | static inline void remap_area_pte(pte_t * pte, unsigned long address, |
| 19 | phys_t size, phys_t phys_addr, unsigned long flags) |
| 20 | { |
| 21 | phys_t end; |
| 22 | unsigned long pfn; |
| 23 | pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE |
| 24 | | __WRITEABLE | flags); |
| 25 | |
| 26 | address &= ~PMD_MASK; |
| 27 | end = address + size; |
| 28 | if (end > PMD_SIZE) |
| 29 | end = PMD_SIZE; |
| 30 | if (address >= end) |
| 31 | BUG(); |
| 32 | pfn = phys_addr >> PAGE_SHIFT; |
| 33 | do { |
| 34 | if (!pte_none(*pte)) { |
| 35 | printk("remap_area_pte: page already exists\n"); |
| 36 | BUG(); |
| 37 | } |
| 38 | set_pte(pte, pfn_pte(pfn, pgprot)); |
| 39 | address += PAGE_SIZE; |
| 40 | pfn++; |
| 41 | pte++; |
| 42 | } while (address && (address < end)); |
| 43 | } |
| 44 | |
| 45 | static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, |
| 46 | phys_t size, phys_t phys_addr, unsigned long flags) |
| 47 | { |
| 48 | phys_t end; |
| 49 | |
| 50 | address &= ~PGDIR_MASK; |
| 51 | end = address + size; |
| 52 | if (end > PGDIR_SIZE) |
| 53 | end = PGDIR_SIZE; |
| 54 | phys_addr -= address; |
| 55 | if (address >= end) |
| 56 | BUG(); |
| 57 | do { |
Hugh Dickins | 872fec1 | 2005-10-29 18:16:21 -0700 | [diff] [blame] | 58 | pte_t * pte = pte_alloc_kernel(pmd, address); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | if (!pte) |
| 60 | return -ENOMEM; |
| 61 | remap_area_pte(pte, address, end - address, address + phys_addr, flags); |
| 62 | address = (address + PMD_SIZE) & PMD_MASK; |
| 63 | pmd++; |
| 64 | } while (address && (address < end)); |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static int remap_area_pages(unsigned long address, phys_t phys_addr, |
| 69 | phys_t size, unsigned long flags) |
| 70 | { |
| 71 | int error; |
| 72 | pgd_t * dir; |
| 73 | unsigned long end = address + size; |
| 74 | |
| 75 | phys_addr -= address; |
| 76 | dir = pgd_offset(&init_mm, address); |
| 77 | flush_cache_all(); |
| 78 | if (address >= end) |
| 79 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | do { |
Ralf Baechle | c6e8b58 | 2005-02-10 12:19:59 +0000 | [diff] [blame] | 81 | pud_t *pud; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | pmd_t *pmd; |
Ralf Baechle | c6e8b58 | 2005-02-10 12:19:59 +0000 | [diff] [blame] | 83 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | error = -ENOMEM; |
Ralf Baechle | c6e8b58 | 2005-02-10 12:19:59 +0000 | [diff] [blame] | 85 | pud = pud_alloc(&init_mm, dir, address); |
| 86 | if (!pud) |
| 87 | break; |
| 88 | pmd = pmd_alloc(&init_mm, pud, address); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | if (!pmd) |
| 90 | break; |
| 91 | if (remap_area_pmd(pmd, address, end - address, |
| 92 | phys_addr + address, flags)) |
| 93 | break; |
| 94 | error = 0; |
| 95 | address = (address + PGDIR_SIZE) & PGDIR_MASK; |
| 96 | dir++; |
| 97 | } while (address && (address < end)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | flush_tlb_all(); |
| 99 | return error; |
| 100 | } |
| 101 | |
| 102 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | * Generic mapping function (not visible outside): |
| 104 | */ |
| 105 | |
| 106 | /* |
| 107 | * Remap an arbitrary physical address space into the kernel virtual |
| 108 | * address space. Needed when the kernel wants to access high addresses |
| 109 | * directly. |
| 110 | * |
| 111 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously |
| 112 | * have to convert them into an offset in a page-aligned mapping, but the |
| 113 | * caller shouldn't need to know that small detail. |
| 114 | */ |
| 115 | |
| 116 | #define IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL)) |
| 117 | |
Maciej W. Rozycki | c3455b0 | 2005-06-30 10:48:40 +0000 | [diff] [blame] | 118 | void __iomem * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | { |
| 120 | struct vm_struct * area; |
| 121 | unsigned long offset; |
| 122 | phys_t last_addr; |
| 123 | void * addr; |
| 124 | |
| 125 | phys_addr = fixup_bigphys_addr(phys_addr, size); |
| 126 | |
| 127 | /* Don't allow wraparound or zero size */ |
| 128 | last_addr = phys_addr + size - 1; |
| 129 | if (!size || last_addr < phys_addr) |
| 130 | return NULL; |
| 131 | |
| 132 | /* |
| 133 | * Map uncached objects in the low 512mb of address space using KSEG1, |
| 134 | * otherwise map using page tables. |
| 135 | */ |
| 136 | if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) && |
| 137 | flags == _CACHE_UNCACHED) |
Maciej W. Rozycki | c3455b0 | 2005-06-30 10:48:40 +0000 | [diff] [blame] | 138 | return (void __iomem *) CKSEG1ADDR(phys_addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | |
| 140 | /* |
| 141 | * Don't allow anybody to remap normal RAM that we're using.. |
| 142 | */ |
| 143 | if (phys_addr < virt_to_phys(high_memory)) { |
| 144 | char *t_addr, *t_end; |
| 145 | struct page *page; |
| 146 | |
| 147 | t_addr = __va(phys_addr); |
| 148 | t_end = t_addr + (size - 1); |
| 149 | |
| 150 | for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) |
| 151 | if(!PageReserved(page)) |
| 152 | return NULL; |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * Mappings have to be page-aligned |
| 157 | */ |
| 158 | offset = phys_addr & ~PAGE_MASK; |
| 159 | phys_addr &= PAGE_MASK; |
| 160 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; |
| 161 | |
| 162 | /* |
| 163 | * Ok, go for it.. |
| 164 | */ |
| 165 | area = get_vm_area(size, VM_IOREMAP); |
| 166 | if (!area) |
| 167 | return NULL; |
| 168 | addr = area->addr; |
| 169 | if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { |
| 170 | vunmap(addr); |
| 171 | return NULL; |
| 172 | } |
| 173 | |
Maciej W. Rozycki | c3455b0 | 2005-06-30 10:48:40 +0000 | [diff] [blame] | 174 | return (void __iomem *) (offset + (char *)addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | } |
| 176 | |
Ralf Baechle | c6e8b58 | 2005-02-10 12:19:59 +0000 | [diff] [blame] | 177 | #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
Ralf Baechle | d89e36d | 2006-10-19 14:21:47 +0100 | [diff] [blame] | 179 | void __iounmap(const volatile void __iomem *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | { |
| 181 | struct vm_struct *p; |
| 182 | |
| 183 | if (IS_KSEG1(addr)) |
| 184 | return; |
| 185 | |
| 186 | p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr)); |
Ralf Baechle | c6e8b58 | 2005-02-10 12:19:59 +0000 | [diff] [blame] | 187 | if (!p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | printk(KERN_ERR "iounmap: bad address %p\n", addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | |
| 190 | kfree(p); |
| 191 | } |
| 192 | |
| 193 | EXPORT_SYMBOL(__ioremap); |
| 194 | EXPORT_SYMBOL(__iounmap); |