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1da177e4 LT |
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> | |
e8edc6e0 | 12 | #include <linux/sched.h> |
5a0e3ad6 | 13 | #include <linux/slab.h> |
1da177e4 | 14 | #include <linux/vmalloc.h> |
5ce704f8 RB |
15 | #include <asm/cacheflush.h> |
16 | #include <asm/io.h> | |
17 | #include <asm/tlbflush.h> | |
18 | ||
19 | static inline void remap_area_pte(pte_t * pte, unsigned long address, | |
15d45cce | 20 | phys_addr_t size, phys_addr_t phys_addr, unsigned long flags) |
5ce704f8 | 21 | { |
15d45cce | 22 | phys_addr_t end; |
5ce704f8 RB |
23 | unsigned long pfn; |
24 | pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE | |
70342287 | 25 | | __WRITEABLE | flags); |
5ce704f8 RB |
26 | |
27 | address &= ~PMD_MASK; | |
28 | end = address + size; | |
29 | if (end > PMD_SIZE) | |
30 | end = PMD_SIZE; | |
b72b7092 | 31 | BUG_ON(address >= end); |
5ce704f8 RB |
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, | |
15d45cce | 46 | phys_addr_t size, phys_addr_t phys_addr, unsigned long flags) |
5ce704f8 | 47 | { |
15d45cce | 48 | phys_addr_t end; |
5ce704f8 RB |
49 | |
50 | address &= ~PGDIR_MASK; | |
51 | end = address + size; | |
52 | if (end > PGDIR_SIZE) | |
53 | end = PGDIR_SIZE; | |
54 | phys_addr -= address; | |
b72b7092 | 55 | BUG_ON(address >= end); |
5ce704f8 RB |
56 | do { |
57 | pte_t * pte = pte_alloc_kernel(pmd, address); | |
58 | if (!pte) | |
59 | return -ENOMEM; | |
60 | remap_area_pte(pte, address, end - address, address + phys_addr, flags); | |
61 | address = (address + PMD_SIZE) & PMD_MASK; | |
62 | pmd++; | |
63 | } while (address && (address < end)); | |
64 | return 0; | |
65 | } | |
66 | ||
15d45cce RB |
67 | static int remap_area_pages(unsigned long address, phys_addr_t phys_addr, |
68 | phys_addr_t size, unsigned long flags) | |
5ce704f8 RB |
69 | { |
70 | int error; | |
71 | pgd_t * dir; | |
72 | unsigned long end = address + size; | |
73 | ||
74 | phys_addr -= address; | |
75 | dir = pgd_offset(&init_mm, address); | |
76 | flush_cache_all(); | |
b72b7092 | 77 | BUG_ON(address >= end); |
5ce704f8 RB |
78 | do { |
79 | pud_t *pud; | |
80 | pmd_t *pmd; | |
81 | ||
82 | error = -ENOMEM; | |
83 | pud = pud_alloc(&init_mm, dir, address); | |
84 | if (!pud) | |
85 | break; | |
86 | pmd = pmd_alloc(&init_mm, pud, address); | |
87 | if (!pmd) | |
88 | break; | |
89 | if (remap_area_pmd(pmd, address, end - address, | |
90 | phys_addr + address, flags)) | |
91 | break; | |
92 | error = 0; | |
93 | address = (address + PGDIR_SIZE) & PGDIR_MASK; | |
94 | dir++; | |
95 | } while (address && (address < end)); | |
96 | flush_tlb_all(); | |
97 | return error; | |
98 | } | |
1da177e4 | 99 | |
1da177e4 LT |
100 | /* |
101 | * Generic mapping function (not visible outside): | |
102 | */ | |
103 | ||
104 | /* | |
105 | * Remap an arbitrary physical address space into the kernel virtual | |
106 | * address space. Needed when the kernel wants to access high addresses | |
107 | * directly. | |
108 | * | |
109 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
110 | * have to convert them into an offset in a page-aligned mapping, but the | |
111 | * caller shouldn't need to know that small detail. | |
112 | */ | |
113 | ||
15d45cce | 114 | #define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL)) |
1da177e4 | 115 | |
15d45cce | 116 | void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long flags) |
1da177e4 LT |
117 | { |
118 | struct vm_struct * area; | |
119 | unsigned long offset; | |
15d45cce | 120 | phys_addr_t last_addr; |
1da177e4 LT |
121 | void * addr; |
122 | ||
123 | phys_addr = fixup_bigphys_addr(phys_addr, size); | |
124 | ||
125 | /* Don't allow wraparound or zero size */ | |
126 | last_addr = phys_addr + size - 1; | |
127 | if (!size || last_addr < phys_addr) | |
128 | return NULL; | |
129 | ||
130 | /* | |
131 | * Map uncached objects in the low 512mb of address space using KSEG1, | |
132 | * otherwise map using page tables. | |
133 | */ | |
134 | if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) && | |
135 | flags == _CACHE_UNCACHED) | |
c3455b0e | 136 | return (void __iomem *) CKSEG1ADDR(phys_addr); |
1da177e4 LT |
137 | |
138 | /* | |
139 | * Don't allow anybody to remap normal RAM that we're using.. | |
140 | */ | |
141 | if (phys_addr < virt_to_phys(high_memory)) { | |
142 | char *t_addr, *t_end; | |
143 | struct page *page; | |
144 | ||
145 | t_addr = __va(phys_addr); | |
146 | t_end = t_addr + (size - 1); | |
147 | ||
148 | for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) | |
149 | if(!PageReserved(page)) | |
150 | return NULL; | |
151 | } | |
152 | ||
153 | /* | |
154 | * Mappings have to be page-aligned | |
155 | */ | |
156 | offset = phys_addr & ~PAGE_MASK; | |
157 | phys_addr &= PAGE_MASK; | |
158 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; | |
159 | ||
160 | /* | |
161 | * Ok, go for it.. | |
162 | */ | |
163 | area = get_vm_area(size, VM_IOREMAP); | |
164 | if (!area) | |
165 | return NULL; | |
166 | addr = area->addr; | |
5ce704f8 | 167 | if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { |
1da177e4 LT |
168 | vunmap(addr); |
169 | return NULL; | |
170 | } | |
171 | ||
c3455b0e | 172 | return (void __iomem *) (offset + (char *)addr); |
1da177e4 LT |
173 | } |
174 | ||
c6e8b587 | 175 | #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1) |
1da177e4 | 176 | |
d89e36d8 | 177 | void __iounmap(const volatile void __iomem *addr) |
1da177e4 LT |
178 | { |
179 | struct vm_struct *p; | |
180 | ||
181 | if (IS_KSEG1(addr)) | |
182 | return; | |
183 | ||
184 | p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr)); | |
c6e8b587 | 185 | if (!p) |
1da177e4 | 186 | printk(KERN_ERR "iounmap: bad address %p\n", addr); |
1da177e4 | 187 | |
70342287 | 188 | kfree(p); |
1da177e4 LT |
189 | } |
190 | ||
191 | EXPORT_SYMBOL(__ioremap); | |
192 | EXPORT_SYMBOL(__iounmap); |