1 | /* |
2 | * fixmap.h: compile-time virtual memory allocation |
3 | * |
4 | * This file is subject to the terms and conditions of the GNU General Public |
5 | * License. See the file "COPYING" in the main directory of this archive |
6 | * for more details. |
7 | * |
8 | * Copyright (C) 1998 Ingo Molnar |
9 | * |
10 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 |
11 | * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009 |
12 | * Break out common bits to asm-generic by Mark Salter, November 2013 |
13 | */ |
14 | |
15 | #ifndef __ASM_GENERIC_FIXMAP_H |
16 | #define __ASM_GENERIC_FIXMAP_H |
17 | |
18 | #include <linux/bug.h> |
19 | #include <linux/mm_types.h> |
20 | |
21 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) |
22 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) |
23 | |
24 | #ifndef __ASSEMBLY__ |
25 | /* |
26 | * 'index to address' translation. If anyone tries to use the idx |
27 | * directly without translation, we catch the bug with a NULL-deference |
28 | * kernel oops. Illegal ranges of incoming indices are caught too. |
29 | */ |
30 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) |
31 | { |
32 | BUILD_BUG_ON(idx >= __end_of_fixed_addresses); |
33 | return __fix_to_virt(idx); |
34 | } |
35 | |
36 | static inline unsigned long virt_to_fix(const unsigned long vaddr) |
37 | { |
38 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); |
39 | return __virt_to_fix(vaddr); |
40 | } |
41 | |
42 | /* |
43 | * Provide some reasonable defaults for page flags. |
44 | * Not all architectures use all of these different types and some |
45 | * architectures use different names. |
46 | */ |
47 | #ifndef FIXMAP_PAGE_NORMAL |
48 | #define FIXMAP_PAGE_NORMAL PAGE_KERNEL |
49 | #endif |
50 | #if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO) |
51 | #define FIXMAP_PAGE_RO PAGE_KERNEL_RO |
52 | #endif |
53 | #ifndef FIXMAP_PAGE_NOCACHE |
54 | #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE |
55 | #endif |
56 | #ifndef FIXMAP_PAGE_IO |
57 | #define FIXMAP_PAGE_IO PAGE_KERNEL_IO |
58 | #endif |
59 | #ifndef FIXMAP_PAGE_CLEAR |
60 | #define FIXMAP_PAGE_CLEAR __pgprot(0) |
61 | #endif |
62 | |
63 | #ifndef set_fixmap |
64 | #define set_fixmap(idx, phys) \ |
65 | __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL) |
66 | #endif |
67 | |
68 | #ifndef clear_fixmap |
69 | #define clear_fixmap(idx) \ |
70 | __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR) |
71 | #endif |
72 | |
73 | /* Return a pointer with offset calculated */ |
74 | #define __set_fixmap_offset(idx, phys, flags) \ |
75 | ({ \ |
76 | unsigned long ________addr; \ |
77 | __set_fixmap(idx, phys, flags); \ |
78 | ________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \ |
79 | ________addr; \ |
80 | }) |
81 | |
82 | #define set_fixmap_offset(idx, phys) \ |
83 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL) |
84 | |
85 | /* |
86 | * Some hardware wants to get fixmapped without caching. |
87 | */ |
88 | #define set_fixmap_nocache(idx, phys) \ |
89 | __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE) |
90 | |
91 | #define set_fixmap_offset_nocache(idx, phys) \ |
92 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE) |
93 | |
94 | /* |
95 | * Some fixmaps are for IO |
96 | */ |
97 | #define set_fixmap_io(idx, phys) \ |
98 | __set_fixmap(idx, phys, FIXMAP_PAGE_IO) |
99 | |
100 | #define set_fixmap_offset_io(idx, phys) \ |
101 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO) |
102 | |
103 | #endif /* __ASSEMBLY__ */ |
104 | #endif /* __ASM_GENERIC_FIXMAP_H */ |
105 | |