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5f97f7f9 HS |
1 | /* |
2 | * Copyright (C) 2004-2006 Atmel Corporation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | #include <linux/vmalloc.h> | |
9 | #include <linux/module.h> | |
86c8eb36 | 10 | #include <linux/io.h> |
5f97f7f9 | 11 | |
5f97f7f9 | 12 | #include <asm/pgtable.h> |
5f97f7f9 HS |
13 | #include <asm/addrspace.h> |
14 | ||
5f97f7f9 HS |
15 | /* |
16 | * Re-map an arbitrary physical address space into the kernel virtual | |
17 | * address space. Needed when the kernel wants to access physical | |
18 | * memory directly. | |
19 | */ | |
20 | void __iomem *__ioremap(unsigned long phys_addr, size_t size, | |
21 | unsigned long flags) | |
22 | { | |
86c8eb36 | 23 | unsigned long addr; |
5f97f7f9 HS |
24 | struct vm_struct *area; |
25 | unsigned long offset, last_addr; | |
26 | pgprot_t prot; | |
27 | ||
28 | /* | |
29 | * Check if we can simply use the P4 segment. This area is | |
30 | * uncacheable, so if caching/buffering is requested, we can't | |
31 | * use it. | |
32 | */ | |
33 | if ((phys_addr >= P4SEG) && (flags == 0)) | |
34 | return (void __iomem *)phys_addr; | |
35 | ||
36 | /* Don't allow wraparound or zero size */ | |
37 | last_addr = phys_addr + size - 1; | |
38 | if (!size || last_addr < phys_addr) | |
39 | return NULL; | |
40 | ||
41 | /* | |
42 | * XXX: When mapping regular RAM, we'd better make damn sure | |
43 | * it's never used for anything else. But this is really the | |
44 | * caller's responsibility... | |
45 | */ | |
46 | if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr) | |
47 | return (void __iomem *)P2SEGADDR(phys_addr); | |
48 | ||
49 | /* Mappings have to be page-aligned */ | |
50 | offset = phys_addr & ~PAGE_MASK; | |
51 | phys_addr &= PAGE_MASK; | |
52 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; | |
53 | ||
86c8eb36 | 54 | prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY |
5f97f7f9 HS |
55 | | _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags); |
56 | ||
57 | /* | |
58 | * Ok, go for it.. | |
59 | */ | |
60 | area = get_vm_area(size, VM_IOREMAP); | |
61 | if (!area) | |
62 | return NULL; | |
63 | area->phys_addr = phys_addr; | |
86c8eb36 HS |
64 | addr = (unsigned long )area->addr; |
65 | if (ioremap_page_range(addr, addr + size, phys_addr, prot)) { | |
66 | vunmap((void *)addr); | |
5f97f7f9 HS |
67 | return NULL; |
68 | } | |
69 | ||
70 | return (void __iomem *)(offset + (char *)addr); | |
71 | } | |
72 | EXPORT_SYMBOL(__ioremap); | |
73 | ||
74 | void __iounmap(void __iomem *addr) | |
75 | { | |
76 | struct vm_struct *p; | |
77 | ||
78 | if ((unsigned long)addr >= P4SEG) | |
79 | return; | |
80 | ||
81 | p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr)); | |
82 | if (unlikely(!p)) { | |
83 | printk (KERN_ERR "iounmap: bad address %p\n", addr); | |
84 | return; | |
85 | } | |
86 | ||
87 | kfree (p); | |
88 | } | |
89 | EXPORT_SYMBOL(__iounmap); |