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1da177e4 LT |
1 | /* |
2 | * linux/arch/m32r/mm/ioremap.c | |
3 | * | |
4 | * Copyright (c) 2001, 2002 Hiroyuki Kondo | |
5 | * | |
6 | * Taken from mips version. | |
7 | * (C) Copyright 1995 1996 Linus Torvalds | |
8 | * (C) Copyright 2001 Ralf Baechle | |
9 | */ | |
10 | ||
11 | /* | |
12 | * This file is subject to the terms and conditions of the GNU General Public | |
13 | * License. See the file "COPYING" in the main directory of this archive | |
14 | * for more details. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/module.h> | |
19 | #include <asm/addrspace.h> | |
20 | #include <asm/byteorder.h> | |
21 | ||
22 | #include <linux/vmalloc.h> | |
9540fc42 | 23 | #include <linux/io.h> |
1da177e4 | 24 | #include <asm/pgalloc.h> |
1da177e4 LT |
25 | |
26 | /* | |
27 | * Generic mapping function (not visible outside): | |
28 | */ | |
29 | ||
30 | /* | |
31 | * Remap an arbitrary physical address space into the kernel virtual | |
32 | * address space. Needed when the kernel wants to access high addresses | |
33 | * directly. | |
34 | * | |
35 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
36 | * have to convert them into an offset in a page-aligned mapping, but the | |
37 | * caller shouldn't need to know that small detail. | |
38 | */ | |
39 | ||
40 | #define IS_LOW512(addr) (!((unsigned long)(addr) & ~0x1fffffffUL)) | |
41 | ||
42 | void __iomem * | |
43 | __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) | |
44 | { | |
45 | void __iomem * addr; | |
46 | struct vm_struct * area; | |
47 | unsigned long offset, last_addr; | |
9540fc42 | 48 | pgprot_t pgprot; |
1da177e4 LT |
49 | |
50 | /* Don't allow wraparound or zero size */ | |
51 | last_addr = phys_addr + size - 1; | |
52 | if (!size || last_addr < phys_addr) | |
53 | return NULL; | |
54 | ||
55 | /* | |
56 | * Map objects in the low 512mb of address space using KSEG1, otherwise | |
57 | * map using page tables. | |
58 | */ | |
59 | if (IS_LOW512(phys_addr) && IS_LOW512(phys_addr + size - 1)) | |
60 | return (void *) KSEG1ADDR(phys_addr); | |
61 | ||
62 | /* | |
63 | * Don't allow anybody to remap normal RAM that we're using.. | |
64 | */ | |
65 | if (phys_addr < virt_to_phys(high_memory)) { | |
66 | char *t_addr, *t_end; | |
67 | struct page *page; | |
68 | ||
69 | t_addr = __va(phys_addr); | |
70 | t_end = t_addr + (size - 1); | |
71 | ||
72 | for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) | |
73 | if(!PageReserved(page)) | |
74 | return NULL; | |
75 | } | |
76 | ||
9540fc42 HS |
77 | pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ |
78 | | _PAGE_WRITE | flags); | |
79 | ||
1da177e4 LT |
80 | /* |
81 | * Mappings have to be page-aligned | |
82 | */ | |
83 | offset = phys_addr & ~PAGE_MASK; | |
84 | phys_addr &= PAGE_MASK; | |
85 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; | |
86 | ||
87 | /* | |
88 | * Ok, go for it.. | |
89 | */ | |
90 | area = get_vm_area(size, VM_IOREMAP); | |
91 | if (!area) | |
92 | return NULL; | |
93 | area->phys_addr = phys_addr; | |
94 | addr = (void __iomem *) area->addr; | |
9540fc42 HS |
95 | if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, |
96 | phys_addr, pgprot)) { | |
1da177e4 LT |
97 | vunmap((void __force *) addr); |
98 | return NULL; | |
99 | } | |
100 | ||
101 | return (void __iomem *) (offset + (char __iomem *)addr); | |
102 | } | |
103 | ||
104 | #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1) | |
105 | ||
106 | void iounmap(volatile void __iomem *addr) | |
107 | { | |
108 | if (!IS_KSEG1(addr)) | |
109 | vfree((void *) (PAGE_MASK & (unsigned long) addr)); | |
110 | } | |
111 |