diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-mips/fixmap.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-mips/fixmap.h')
-rw-r--r-- | include/asm-mips/fixmap.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/include/asm-mips/fixmap.h b/include/asm-mips/fixmap.h new file mode 100644 index 000000000000..26b6a90a690b --- /dev/null +++ b/include/asm-mips/fixmap.h | |||
@@ -0,0 +1,110 @@ | |||
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 | */ | ||
12 | |||
13 | #ifndef _ASM_FIXMAP_H | ||
14 | #define _ASM_FIXMAP_H | ||
15 | |||
16 | #include <linux/config.h> | ||
17 | #include <asm/page.h> | ||
18 | #ifdef CONFIG_HIGHMEM | ||
19 | #include <linux/threads.h> | ||
20 | #include <asm/kmap_types.h> | ||
21 | #endif | ||
22 | |||
23 | /* | ||
24 | * Here we define all the compile-time 'special' virtual | ||
25 | * addresses. The point is to have a constant address at | ||
26 | * compile time, but to set the physical address only | ||
27 | * in the boot process. We allocate these special addresses | ||
28 | * from the end of virtual memory (0xfffff000) backwards. | ||
29 | * Also this lets us do fail-safe vmalloc(), we | ||
30 | * can guarantee that these special addresses and | ||
31 | * vmalloc()-ed addresses never overlap. | ||
32 | * | ||
33 | * these 'compile-time allocated' memory buffers are | ||
34 | * fixed-size 4k pages. (or larger if used with an increment | ||
35 | * highger than 1) use fixmap_set(idx,phys) to associate | ||
36 | * physical memory with fixmap indices. | ||
37 | * | ||
38 | * TLB entries of such buffers will not be flushed across | ||
39 | * task switches. | ||
40 | */ | ||
41 | |||
42 | /* | ||
43 | * on UP currently we will have no trace of the fixmap mechanizm, | ||
44 | * no page table allocations, etc. This might change in the | ||
45 | * future, say framebuffers for the console driver(s) could be | ||
46 | * fix-mapped? | ||
47 | */ | ||
48 | enum fixed_addresses { | ||
49 | #ifdef CONFIG_HIGHMEM | ||
50 | FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ | ||
51 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, | ||
52 | #endif | ||
53 | __end_of_fixed_addresses | ||
54 | }; | ||
55 | |||
56 | extern void __set_fixmap (enum fixed_addresses idx, | ||
57 | unsigned long phys, pgprot_t flags); | ||
58 | |||
59 | #define set_fixmap(idx, phys) \ | ||
60 | __set_fixmap(idx, phys, PAGE_KERNEL) | ||
61 | /* | ||
62 | * Some hardware wants to get fixmapped without caching. | ||
63 | */ | ||
64 | #define set_fixmap_nocache(idx, phys) \ | ||
65 | __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) | ||
66 | /* | ||
67 | * used by vmalloc.c. | ||
68 | * | ||
69 | * Leave one empty page between vmalloc'ed areas and | ||
70 | * the start of the fixmap, and leave one page empty | ||
71 | * at the top of mem.. | ||
72 | */ | ||
73 | #define FIXADDR_TOP (0xffffe000UL) | ||
74 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | ||
75 | #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) | ||
76 | |||
77 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) | ||
78 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) | ||
79 | |||
80 | extern void __this_fixmap_does_not_exist(void); | ||
81 | |||
82 | /* | ||
83 | * 'index to address' translation. If anyone tries to use the idx | ||
84 | * directly without tranlation, we catch the bug with a NULL-deference | ||
85 | * kernel oops. Illegal ranges of incoming indices are caught too. | ||
86 | */ | ||
87 | static inline unsigned long fix_to_virt(const unsigned int idx) | ||
88 | { | ||
89 | /* | ||
90 | * this branch gets completely eliminated after inlining, | ||
91 | * except when someone tries to use fixaddr indices in an | ||
92 | * illegal way. (such as mixing up address types or using | ||
93 | * out-of-range indices). | ||
94 | * | ||
95 | * If it doesn't get removed, the linker will complain | ||
96 | * loudly with a reasonably clear error message.. | ||
97 | */ | ||
98 | if (idx >= __end_of_fixed_addresses) | ||
99 | __this_fixmap_does_not_exist(); | ||
100 | |||
101 | return __fix_to_virt(idx); | ||
102 | } | ||
103 | |||
104 | static inline unsigned long virt_to_fix(const unsigned long vaddr) | ||
105 | { | ||
106 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); | ||
107 | return __virt_to_fix(vaddr); | ||
108 | } | ||
109 | |||
110 | #endif | ||