diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/mm/ioremap.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/mips/mm/ioremap.c')
-rw-r--r-- | arch/mips/mm/ioremap.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c new file mode 100644 index 000000000000..adf352273f63 --- /dev/null +++ b/arch/mips/mm/ioremap.c | |||
@@ -0,0 +1,202 @@ | |||
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 { | ||
58 | pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address); | ||
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(); | ||
80 | spin_lock(&init_mm.page_table_lock); | ||
81 | do { | ||
82 | pmd_t *pmd; | ||
83 | pmd = pmd_alloc(&init_mm, dir, address); | ||
84 | error = -ENOMEM; | ||
85 | if (!pmd) | ||
86 | break; | ||
87 | if (remap_area_pmd(pmd, address, end - address, | ||
88 | phys_addr + address, flags)) | ||
89 | break; | ||
90 | error = 0; | ||
91 | address = (address + PGDIR_SIZE) & PGDIR_MASK; | ||
92 | dir++; | ||
93 | } while (address && (address < end)); | ||
94 | spin_unlock(&init_mm.page_table_lock); | ||
95 | flush_tlb_all(); | ||
96 | return error; | ||
97 | } | ||
98 | |||
99 | /* | ||
100 | * Allow physical addresses to be fixed up to help 36 bit peripherals. | ||
101 | */ | ||
102 | phys_t __attribute__ ((weak)) | ||
103 | fixup_bigphys_addr(phys_t phys_addr, phys_t size) | ||
104 | { | ||
105 | return phys_addr; | ||
106 | } | ||
107 | |||
108 | /* | ||
109 | * Generic mapping function (not visible outside): | ||
110 | */ | ||
111 | |||
112 | /* | ||
113 | * Remap an arbitrary physical address space into the kernel virtual | ||
114 | * address space. Needed when the kernel wants to access high addresses | ||
115 | * directly. | ||
116 | * | ||
117 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | ||
118 | * have to convert them into an offset in a page-aligned mapping, but the | ||
119 | * caller shouldn't need to know that small detail. | ||
120 | */ | ||
121 | |||
122 | #define IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL)) | ||
123 | |||
124 | void * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags) | ||
125 | { | ||
126 | struct vm_struct * area; | ||
127 | unsigned long offset; | ||
128 | phys_t last_addr; | ||
129 | void * addr; | ||
130 | |||
131 | phys_addr = fixup_bigphys_addr(phys_addr, size); | ||
132 | |||
133 | /* Don't allow wraparound or zero size */ | ||
134 | last_addr = phys_addr + size - 1; | ||
135 | if (!size || last_addr < phys_addr) | ||
136 | return NULL; | ||
137 | |||
138 | /* | ||
139 | * Map uncached objects in the low 512mb of address space using KSEG1, | ||
140 | * otherwise map using page tables. | ||
141 | */ | ||
142 | if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) && | ||
143 | flags == _CACHE_UNCACHED) | ||
144 | return (void *) KSEG1ADDR(phys_addr); | ||
145 | |||
146 | /* | ||
147 | * Don't allow anybody to remap normal RAM that we're using.. | ||
148 | */ | ||
149 | if (phys_addr < virt_to_phys(high_memory)) { | ||
150 | char *t_addr, *t_end; | ||
151 | struct page *page; | ||
152 | |||
153 | t_addr = __va(phys_addr); | ||
154 | t_end = t_addr + (size - 1); | ||
155 | |||
156 | for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) | ||
157 | if(!PageReserved(page)) | ||
158 | return NULL; | ||
159 | } | ||
160 | |||
161 | /* | ||
162 | * Mappings have to be page-aligned | ||
163 | */ | ||
164 | offset = phys_addr & ~PAGE_MASK; | ||
165 | phys_addr &= PAGE_MASK; | ||
166 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; | ||
167 | |||
168 | /* | ||
169 | * Ok, go for it.. | ||
170 | */ | ||
171 | area = get_vm_area(size, VM_IOREMAP); | ||
172 | if (!area) | ||
173 | return NULL; | ||
174 | addr = area->addr; | ||
175 | if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { | ||
176 | vunmap(addr); | ||
177 | return NULL; | ||
178 | } | ||
179 | |||
180 | return (void *) (offset + (char *)addr); | ||
181 | } | ||
182 | |||
183 | #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1) | ||
184 | |||
185 | void __iounmap(volatile void __iomem *addr) | ||
186 | { | ||
187 | struct vm_struct *p; | ||
188 | |||
189 | if (IS_KSEG1(addr)) | ||
190 | return; | ||
191 | |||
192 | p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr)); | ||
193 | if (!p) { | ||
194 | printk(KERN_ERR "iounmap: bad address %p\n", addr); | ||
195 | return; | ||
196 | } | ||
197 | |||
198 | kfree(p); | ||
199 | } | ||
200 | |||
201 | EXPORT_SYMBOL(__ioremap); | ||
202 | EXPORT_SYMBOL(__iounmap); | ||