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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 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
11 | */ | |
12 | ||
13 | #ifndef _ASM_FIXMAP_H | |
14 | #define _ASM_FIXMAP_H | |
15 | ||
1da177e4 LT |
16 | |
17 | /* used by vmalloc.c, vsyscall.lds.S. | |
18 | * | |
19 | * Leave one empty page between vmalloc'ed areas and | |
20 | * the start of the fixmap. | |
21 | */ | |
052e7994 | 22 | extern unsigned long __FIXADDR_TOP; |
d4f7a2c1 JF |
23 | #define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) |
24 | #define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) | |
1da177e4 LT |
25 | |
26 | #ifndef __ASSEMBLY__ | |
27 | #include <linux/kernel.h> | |
28 | #include <asm/acpi.h> | |
29 | #include <asm/apicdef.h> | |
30 | #include <asm/page.h> | |
31 | #ifdef CONFIG_HIGHMEM | |
32 | #include <linux/threads.h> | |
33 | #include <asm/kmap_types.h> | |
34 | #endif | |
35 | ||
36 | /* | |
37 | * Here we define all the compile-time 'special' virtual | |
38 | * addresses. The point is to have a constant address at | |
39 | * compile time, but to set the physical address only | |
40 | * in the boot process. We allocate these special addresses | |
41 | * from the end of virtual memory (0xfffff000) backwards. | |
42 | * Also this lets us do fail-safe vmalloc(), we | |
43 | * can guarantee that these special addresses and | |
44 | * vmalloc()-ed addresses never overlap. | |
45 | * | |
46 | * these 'compile-time allocated' memory buffers are | |
47 | * fixed-size 4k pages. (or larger if used with an increment | |
48 | * highger than 1) use fixmap_set(idx,phys) to associate | |
49 | * physical memory with fixmap indices. | |
50 | * | |
51 | * TLB entries of such buffers will not be flushed across | |
52 | * task switches. | |
53 | */ | |
54 | enum fixed_addresses { | |
55 | FIX_HOLE, | |
e6e5494c | 56 | FIX_VDSO, |
1da177e4 LT |
57 | #ifdef CONFIG_X86_LOCAL_APIC |
58 | FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ | |
59 | #endif | |
60 | #ifdef CONFIG_X86_IO_APIC | |
61 | FIX_IO_APIC_BASE_0, | |
62 | FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1, | |
63 | #endif | |
64 | #ifdef CONFIG_X86_VISWS_APIC | |
65 | FIX_CO_CPU, /* Cobalt timer */ | |
66 | FIX_CO_APIC, /* Cobalt APIC Redirection Table */ | |
67 | FIX_LI_PCIA, /* Lithium PCI Bridge A */ | |
68 | FIX_LI_PCIB, /* Lithium PCI Bridge B */ | |
69 | #endif | |
70 | #ifdef CONFIG_X86_F00F_BUG | |
71 | FIX_F00F_IDT, /* Virtual mapping for IDT */ | |
72 | #endif | |
73 | #ifdef CONFIG_X86_CYCLONE_TIMER | |
74 | FIX_CYCLONE_TIMER, /*cyclone timer register*/ | |
75 | #endif | |
76 | #ifdef CONFIG_HIGHMEM | |
77 | FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ | |
78 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, | |
79 | #endif | |
888ba6c6 | 80 | #ifdef CONFIG_ACPI |
1da177e4 LT |
81 | FIX_ACPI_BEGIN, |
82 | FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, | |
83 | #endif | |
84 | #ifdef CONFIG_PCI_MMCONFIG | |
85 | FIX_PCIE_MCFG, | |
86 | #endif | |
87 | __end_of_permanent_fixed_addresses, | |
88 | /* temporary boot-time mappings, used before ioremap() is functional */ | |
89 | #define NR_FIX_BTMAPS 16 | |
90 | FIX_BTMAP_END = __end_of_permanent_fixed_addresses, | |
91 | FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1, | |
92 | FIX_WP_TEST, | |
93 | __end_of_fixed_addresses | |
94 | }; | |
95 | ||
96 | extern void __set_fixmap (enum fixed_addresses idx, | |
97 | unsigned long phys, pgprot_t flags); | |
052e7994 | 98 | extern void reserve_top_address(unsigned long reserve); |
1da177e4 LT |
99 | |
100 | #define set_fixmap(idx, phys) \ | |
101 | __set_fixmap(idx, phys, PAGE_KERNEL) | |
102 | /* | |
103 | * Some hardware wants to get fixmapped without caching. | |
104 | */ | |
105 | #define set_fixmap_nocache(idx, phys) \ | |
106 | __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) | |
107 | ||
108 | #define clear_fixmap(idx) \ | |
109 | __set_fixmap(idx, 0, __pgprot(0)) | |
110 | ||
111 | #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) | |
112 | ||
113 | #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) | |
114 | #define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | |
115 | #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) | |
116 | #define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE) | |
117 | ||
118 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) | |
119 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) | |
120 | ||
1da177e4 LT |
121 | extern void __this_fixmap_does_not_exist(void); |
122 | ||
123 | /* | |
124 | * 'index to address' translation. If anyone tries to use the idx | |
125 | * directly without tranlation, we catch the bug with a NULL-deference | |
126 | * kernel oops. Illegal ranges of incoming indices are caught too. | |
127 | */ | |
128 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) | |
129 | { | |
130 | /* | |
131 | * this branch gets completely eliminated after inlining, | |
132 | * except when someone tries to use fixaddr indices in an | |
133 | * illegal way. (such as mixing up address types or using | |
134 | * out-of-range indices). | |
135 | * | |
136 | * If it doesn't get removed, the linker will complain | |
137 | * loudly with a reasonably clear error message.. | |
138 | */ | |
139 | if (idx >= __end_of_fixed_addresses) | |
140 | __this_fixmap_does_not_exist(); | |
141 | ||
142 | return __fix_to_virt(idx); | |
143 | } | |
144 | ||
145 | static inline unsigned long virt_to_fix(const unsigned long vaddr) | |
146 | { | |
147 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); | |
148 | return __virt_to_fix(vaddr); | |
149 | } | |
150 | ||
151 | #endif /* !__ASSEMBLY__ */ | |
152 | #endif |