Commit | Line | Data |
---|---|---|
373cd784 JH |
1 | /* |
2 | * Re-map IO memory to kernel address space so that we can access it. | |
3 | * Needed for memory-mapped I/O devices mapped outside our normal DRAM | |
4 | * window (that is, all memory-mapped I/O devices). | |
5 | * | |
6 | * Copyright (C) 1995,1996 Linus Torvalds | |
7 | * | |
8 | * Meta port based on CRIS-port by Axis Communications AB | |
9 | */ | |
10 | ||
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/io.h> | |
13 | #include <linux/export.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/mm.h> | |
16 | ||
17 | #include <asm/pgtable.h> | |
18 | ||
19 | /* | |
20 | * Remap an arbitrary physical address space into the kernel virtual | |
21 | * address space. Needed when the kernel wants to access high addresses | |
22 | * directly. | |
23 | * | |
24 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
25 | * have to convert them into an offset in a page-aligned mapping, but the | |
26 | * caller shouldn't need to know that small detail. | |
27 | */ | |
28 | void __iomem *__ioremap(unsigned long phys_addr, size_t size, | |
29 | unsigned long flags) | |
30 | { | |
31 | unsigned long addr; | |
32 | struct vm_struct *area; | |
33 | unsigned long offset, last_addr; | |
34 | pgprot_t prot; | |
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 | /* Custom region addresses are accessible and uncached by default. */ | |
42 | if (phys_addr >= LINSYSCUSTOM_BASE && | |
43 | phys_addr < (LINSYSCUSTOM_BASE + LINSYSCUSTOM_LIMIT)) | |
44 | return (__force void __iomem *) phys_addr; | |
45 | ||
46 | /* | |
47 | * Mappings have to be page-aligned | |
48 | */ | |
49 | offset = phys_addr & ~PAGE_MASK; | |
50 | phys_addr &= PAGE_MASK; | |
51 | size = PAGE_ALIGN(last_addr+1) - phys_addr; | |
52 | prot = __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_DIRTY | | |
53 | _PAGE_ACCESSED | _PAGE_KERNEL | _PAGE_CACHE_WIN0 | | |
54 | flags); | |
55 | ||
56 | /* | |
57 | * Ok, go for it.. | |
58 | */ | |
59 | area = get_vm_area(size, VM_IOREMAP); | |
60 | if (!area) | |
61 | return NULL; | |
62 | area->phys_addr = phys_addr; | |
63 | addr = (unsigned long) area->addr; | |
64 | if (ioremap_page_range(addr, addr + size, phys_addr, prot)) { | |
65 | vunmap((void *) addr); | |
66 | return NULL; | |
67 | } | |
68 | return (__force void __iomem *) (offset + (char *)addr); | |
69 | } | |
70 | EXPORT_SYMBOL(__ioremap); | |
71 | ||
72 | void __iounmap(void __iomem *addr) | |
73 | { | |
74 | struct vm_struct *p; | |
75 | ||
76 | if ((__force unsigned long)addr >= LINSYSCUSTOM_BASE && | |
77 | (__force unsigned long)addr < (LINSYSCUSTOM_BASE + | |
78 | LINSYSCUSTOM_LIMIT)) | |
79 | return; | |
80 | ||
81 | p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr)); | |
82 | if (unlikely(!p)) { | |
83 | pr_err("iounmap: bad address %p\n", addr); | |
84 | return; | |
85 | } | |
86 | ||
87 | kfree(p); | |
88 | } | |
89 | EXPORT_SYMBOL(__iounmap); |