diff options
Diffstat (limited to 'include/asm-x86/fixmap_64.h')
-rw-r--r-- | include/asm-x86/fixmap_64.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/include/asm-x86/fixmap_64.h b/include/asm-x86/fixmap_64.h new file mode 100644 index 000000000000..cdfbe4a6ae6f --- /dev/null +++ b/include/asm-x86/fixmap_64.h | |||
@@ -0,0 +1,92 @@ | |||
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 | |||
11 | #ifndef _ASM_FIXMAP_H | ||
12 | #define _ASM_FIXMAP_H | ||
13 | |||
14 | #include <linux/kernel.h> | ||
15 | #include <asm/apicdef.h> | ||
16 | #include <asm/page.h> | ||
17 | #include <asm/vsyscall.h> | ||
18 | |||
19 | /* | ||
20 | * Here we define all the compile-time 'special' virtual | ||
21 | * addresses. The point is to have a constant address at | ||
22 | * compile time, but to set the physical address only | ||
23 | * in the boot process. | ||
24 | * | ||
25 | * These 'compile-time allocated' memory buffers are | ||
26 | * fixed-size 4k pages (or larger if used with an increment | ||
27 | * higher than 1). Use set_fixmap(idx,phys) to associate | ||
28 | * physical memory with fixmap indices. | ||
29 | * | ||
30 | * TLB entries of such buffers will not be flushed across | ||
31 | * task switches. | ||
32 | */ | ||
33 | |||
34 | enum fixed_addresses { | ||
35 | VSYSCALL_LAST_PAGE, | ||
36 | VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1, | ||
37 | VSYSCALL_HPET, | ||
38 | FIX_DBGP_BASE, | ||
39 | FIX_EARLYCON_MEM_BASE, | ||
40 | FIX_HPET_BASE, | ||
41 | FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ | ||
42 | FIX_IO_APIC_BASE_0, | ||
43 | FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1, | ||
44 | __end_of_fixed_addresses | ||
45 | }; | ||
46 | |||
47 | extern void __set_fixmap (enum fixed_addresses idx, | ||
48 | unsigned long phys, pgprot_t flags); | ||
49 | |||
50 | #define set_fixmap(idx, phys) \ | ||
51 | __set_fixmap(idx, phys, PAGE_KERNEL) | ||
52 | /* | ||
53 | * Some hardware wants to get fixmapped without caching. | ||
54 | */ | ||
55 | #define set_fixmap_nocache(idx, phys) \ | ||
56 | __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) | ||
57 | |||
58 | #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE) | ||
59 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | ||
60 | #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) | ||
61 | |||
62 | /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */ | ||
63 | #define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL) | ||
64 | #define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE) | ||
65 | |||
66 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) | ||
67 | |||
68 | extern void __this_fixmap_does_not_exist(void); | ||
69 | |||
70 | /* | ||
71 | * 'index to address' translation. If anyone tries to use the idx | ||
72 | * directly without translation, we catch the bug with a NULL-deference | ||
73 | * kernel oops. Illegal ranges of incoming indices are caught too. | ||
74 | */ | ||
75 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) | ||
76 | { | ||
77 | /* | ||
78 | * this branch gets completely eliminated after inlining, | ||
79 | * except when someone tries to use fixaddr indices in an | ||
80 | * illegal way. (such as mixing up address types or using | ||
81 | * out-of-range indices). | ||
82 | * | ||
83 | * If it doesn't get removed, the linker will complain | ||
84 | * loudly with a reasonably clear error message.. | ||
85 | */ | ||
86 | if (idx >= __end_of_fixed_addresses) | ||
87 | __this_fixmap_does_not_exist(); | ||
88 | |||
89 | return __fix_to_virt(idx); | ||
90 | } | ||
91 | |||
92 | #endif | ||