Commit | Line | Data |
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1da177e4 LT |
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 | ||
3ec96783 IM |
11 | #ifndef _ASM_FIXMAP_64_H |
12 | #define _ASM_FIXMAP_64_H | |
1da177e4 | 13 | |
1da177e4 LT |
14 | #include <linux/kernel.h> |
15 | #include <asm/apicdef.h> | |
16 | #include <asm/page.h> | |
17 | #include <asm/vsyscall.h> | |
5b83683f | 18 | #include <asm/efi.h> |
1da177e4 LT |
19 | |
20 | /* | |
21 | * Here we define all the compile-time 'special' virtual | |
22 | * addresses. The point is to have a constant address at | |
23 | * compile time, but to set the physical address only | |
24 | * in the boot process. | |
25 | * | |
bdb345a4 JK |
26 | * These 'compile-time allocated' memory buffers are |
27 | * fixed-size 4k pages (or larger if used with an increment | |
28 | * higher than 1). Use set_fixmap(idx,phys) to associate | |
1da177e4 LT |
29 | * physical memory with fixmap indices. |
30 | * | |
31 | * TLB entries of such buffers will not be flushed across | |
32 | * task switches. | |
33 | */ | |
34 | ||
35 | enum fixed_addresses { | |
36 | VSYSCALL_LAST_PAGE, | |
dca13fb0 JP |
37 | VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE |
38 | + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1, | |
1da177e4 | 39 | VSYSCALL_HPET, |
18a8bd94 YL |
40 | FIX_DBGP_BASE, |
41 | FIX_EARLYCON_MEM_BASE, | |
1da177e4 | 42 | FIX_HPET_BASE, |
1da177e4 | 43 | FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ |
1da177e4 | 44 | FIX_IO_APIC_BASE_0, |
dca13fb0 | 45 | FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, |
5b83683f | 46 | FIX_EFI_IO_MAP_LAST_PAGE, |
dca13fb0 JP |
47 | FIX_EFI_IO_MAP_FIRST_PAGE = FIX_EFI_IO_MAP_LAST_PAGE |
48 | + MAX_EFI_IO_PAGES - 1, | |
f212ec4b BK |
49 | #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT |
50 | FIX_OHCI1394_BASE, | |
51 | #endif | |
1da177e4 LT |
52 | __end_of_fixed_addresses |
53 | }; | |
54 | ||
dca13fb0 JP |
55 | extern void __set_fixmap(enum fixed_addresses idx, |
56 | unsigned long phys, pgprot_t flags); | |
1da177e4 | 57 | |
dca13fb0 JP |
58 | #define set_fixmap(idx, phys) \ |
59 | __set_fixmap(idx, phys, PAGE_KERNEL) | |
1da177e4 LT |
60 | /* |
61 | * Some hardware wants to get fixmapped without caching. | |
62 | */ | |
dca13fb0 JP |
63 | #define set_fixmap_nocache(idx, phys) \ |
64 | __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) | |
1da177e4 LT |
65 | |
66 | #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE) | |
67 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | |
68 | #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) | |
69 | ||
70 | /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */ | |
71 | #define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL) | |
72 | #define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE) | |
73 | ||
74 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) | |
75 | ||
76 | extern void __this_fixmap_does_not_exist(void); | |
77 | ||
78 | /* | |
79 | * 'index to address' translation. If anyone tries to use the idx | |
80 | * directly without translation, we catch the bug with a NULL-deference | |
81 | * kernel oops. Illegal ranges of incoming indices are caught too. | |
82 | */ | |
652050ae | 83 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) |
1da177e4 LT |
84 | { |
85 | /* | |
86 | * this branch gets completely eliminated after inlining, | |
87 | * except when someone tries to use fixaddr indices in an | |
88 | * illegal way. (such as mixing up address types or using | |
89 | * out-of-range indices). | |
90 | * | |
91 | * If it doesn't get removed, the linker will complain | |
92 | * loudly with a reasonably clear error message.. | |
93 | */ | |
94 | if (idx >= __end_of_fixed_addresses) | |
95 | __this_fixmap_does_not_exist(); | |
96 | ||
18a8bd94 | 97 | return __fix_to_virt(idx); |
1da177e4 LT |
98 | } |
99 | ||
100 | #endif |