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867e359b CM |
1 | /* |
2 | * Copyright (C) 1998 Ingo Molnar | |
3 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation, version 2. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
12 | * NON INFRINGEMENT. See the GNU General Public License for | |
13 | * more details. | |
14 | */ | |
15 | ||
16 | #ifndef _ASM_TILE_FIXMAP_H | |
17 | #define _ASM_TILE_FIXMAP_H | |
18 | ||
19 | #include <asm/page.h> | |
20 | ||
21 | #ifndef __ASSEMBLY__ | |
22 | #include <linux/kernel.h> | |
23 | #ifdef CONFIG_HIGHMEM | |
24 | #include <linux/threads.h> | |
25 | #include <asm/kmap_types.h> | |
26 | #endif | |
27 | ||
28 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) | |
29 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) | |
30 | ||
31 | /* | |
32 | * Here we define all the compile-time 'special' virtual | |
33 | * addresses. The point is to have a constant address at | |
34 | * compile time, but to set the physical address only | |
35 | * in the boot process. We allocate these special addresses | |
36 | * from the end of supervisor virtual memory backwards. | |
37 | * Also this lets us do fail-safe vmalloc(), we | |
38 | * can guarantee that these special addresses and | |
39 | * vmalloc()-ed addresses never overlap. | |
40 | * | |
41 | * these 'compile-time allocated' memory buffers are | |
42 | * fixed-size 4k pages. (or larger if used with an increment | |
43 | * higher than 1) use fixmap_set(idx,phys) to associate | |
44 | * physical memory with fixmap indices. | |
45 | * | |
46 | * TLB entries of such buffers will not be flushed across | |
47 | * task switches. | |
48 | * | |
49 | * We don't bother with a FIX_HOLE since above the fixmaps | |
50 | * is unmapped memory in any case. | |
51 | */ | |
52 | enum fixed_addresses { | |
53 | #ifdef CONFIG_HIGHMEM | |
54 | FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ | |
55 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, | |
56 | #endif | |
57 | __end_of_permanent_fixed_addresses, | |
58 | ||
59 | /* | |
60 | * Temporary boot-time mappings, used before ioremap() is functional. | |
61 | * Not currently needed by the Tile architecture. | |
62 | */ | |
63 | #define NR_FIX_BTMAPS 0 | |
64 | #if NR_FIX_BTMAPS | |
65 | FIX_BTMAP_END = __end_of_permanent_fixed_addresses, | |
66 | FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1, | |
67 | __end_of_fixed_addresses | |
68 | #else | |
69 | __end_of_fixed_addresses = __end_of_permanent_fixed_addresses | |
70 | #endif | |
71 | }; | |
72 | ||
73 | extern void __set_fixmap(enum fixed_addresses idx, | |
74 | unsigned long phys, pgprot_t flags); | |
75 | ||
76 | #define set_fixmap(idx, phys) \ | |
77 | __set_fixmap(idx, phys, PAGE_KERNEL) | |
78 | /* | |
79 | * Some hardware wants to get fixmapped without caching. | |
80 | */ | |
81 | #define set_fixmap_nocache(idx, phys) \ | |
82 | __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) | |
83 | ||
84 | #define clear_fixmap(idx) \ | |
85 | __set_fixmap(idx, 0, __pgprot(0)) | |
86 | ||
87 | #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) | |
88 | #define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | |
89 | #define FIXADDR_START (FIXADDR_TOP + PAGE_SIZE - __FIXADDR_SIZE) | |
90 | #define FIXADDR_BOOT_START (FIXADDR_TOP + PAGE_SIZE - __FIXADDR_BOOT_SIZE) | |
91 | ||
92 | extern void __this_fixmap_does_not_exist(void); | |
93 | ||
94 | /* | |
95 | * 'index to address' translation. If anyone tries to use the idx | |
96 | * directly without tranlation, we catch the bug with a NULL-deference | |
97 | * kernel oops. Illegal ranges of incoming indices are caught too. | |
98 | */ | |
99 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) | |
100 | { | |
101 | /* | |
102 | * this branch gets completely eliminated after inlining, | |
103 | * except when someone tries to use fixaddr indices in an | |
104 | * illegal way. (such as mixing up address types or using | |
105 | * out-of-range indices). | |
106 | * | |
107 | * If it doesn't get removed, the linker will complain | |
108 | * loudly with a reasonably clear error message.. | |
109 | */ | |
110 | if (idx >= __end_of_fixed_addresses) | |
111 | __this_fixmap_does_not_exist(); | |
112 | ||
113 | return __fix_to_virt(idx); | |
114 | } | |
115 | ||
116 | static inline unsigned long virt_to_fix(const unsigned long vaddr) | |
117 | { | |
118 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); | |
119 | return __virt_to_fix(vaddr); | |
120 | } | |
121 | ||
122 | #endif /* !__ASSEMBLY__ */ | |
123 | ||
124 | #endif /* _ASM_TILE_FIXMAP_H */ |