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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 JF |
22 | #ifndef CONFIG_COMPAT_VDSO |
23 | extern unsigned long __FIXADDR_TOP; | |
24 | #else | |
25 | #define __FIXADDR_TOP 0xfffff000 | |
a1f3bb9a RM |
26 | #define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) |
27 | #define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) | |
052e7994 | 28 | #endif |
1da177e4 LT |
29 | |
30 | #ifndef __ASSEMBLY__ | |
31 | #include <linux/kernel.h> | |
32 | #include <asm/acpi.h> | |
33 | #include <asm/apicdef.h> | |
34 | #include <asm/page.h> | |
35 | #ifdef CONFIG_HIGHMEM | |
36 | #include <linux/threads.h> | |
37 | #include <asm/kmap_types.h> | |
38 | #endif | |
39 | ||
40 | /* | |
41 | * Here we define all the compile-time 'special' virtual | |
42 | * addresses. The point is to have a constant address at | |
43 | * compile time, but to set the physical address only | |
44 | * in the boot process. We allocate these special addresses | |
45 | * from the end of virtual memory (0xfffff000) backwards. | |
46 | * Also this lets us do fail-safe vmalloc(), we | |
47 | * can guarantee that these special addresses and | |
48 | * vmalloc()-ed addresses never overlap. | |
49 | * | |
50 | * these 'compile-time allocated' memory buffers are | |
51 | * fixed-size 4k pages. (or larger if used with an increment | |
52 | * highger than 1) use fixmap_set(idx,phys) to associate | |
53 | * physical memory with fixmap indices. | |
54 | * | |
55 | * TLB entries of such buffers will not be flushed across | |
56 | * task switches. | |
57 | */ | |
58 | enum fixed_addresses { | |
59 | FIX_HOLE, | |
e6e5494c | 60 | FIX_VDSO, |
1da177e4 LT |
61 | #ifdef CONFIG_X86_LOCAL_APIC |
62 | FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ | |
63 | #endif | |
64 | #ifdef CONFIG_X86_IO_APIC | |
65 | FIX_IO_APIC_BASE_0, | |
66 | FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1, | |
67 | #endif | |
68 | #ifdef CONFIG_X86_VISWS_APIC | |
69 | FIX_CO_CPU, /* Cobalt timer */ | |
70 | FIX_CO_APIC, /* Cobalt APIC Redirection Table */ | |
71 | FIX_LI_PCIA, /* Lithium PCI Bridge A */ | |
72 | FIX_LI_PCIB, /* Lithium PCI Bridge B */ | |
73 | #endif | |
74 | #ifdef CONFIG_X86_F00F_BUG | |
75 | FIX_F00F_IDT, /* Virtual mapping for IDT */ | |
76 | #endif | |
77 | #ifdef CONFIG_X86_CYCLONE_TIMER | |
78 | FIX_CYCLONE_TIMER, /*cyclone timer register*/ | |
79 | #endif | |
80 | #ifdef CONFIG_HIGHMEM | |
81 | FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ | |
82 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, | |
83 | #endif | |
888ba6c6 | 84 | #ifdef CONFIG_ACPI |
1da177e4 LT |
85 | FIX_ACPI_BEGIN, |
86 | FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, | |
87 | #endif | |
88 | #ifdef CONFIG_PCI_MMCONFIG | |
89 | FIX_PCIE_MCFG, | |
90 | #endif | |
91 | __end_of_permanent_fixed_addresses, | |
92 | /* temporary boot-time mappings, used before ioremap() is functional */ | |
93 | #define NR_FIX_BTMAPS 16 | |
94 | FIX_BTMAP_END = __end_of_permanent_fixed_addresses, | |
95 | FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1, | |
96 | FIX_WP_TEST, | |
97 | __end_of_fixed_addresses | |
98 | }; | |
99 | ||
100 | extern void __set_fixmap (enum fixed_addresses idx, | |
101 | unsigned long phys, pgprot_t flags); | |
052e7994 | 102 | extern void reserve_top_address(unsigned long reserve); |
1da177e4 LT |
103 | |
104 | #define set_fixmap(idx, phys) \ | |
105 | __set_fixmap(idx, phys, PAGE_KERNEL) | |
106 | /* | |
107 | * Some hardware wants to get fixmapped without caching. | |
108 | */ | |
109 | #define set_fixmap_nocache(idx, phys) \ | |
110 | __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) | |
111 | ||
112 | #define clear_fixmap(idx) \ | |
113 | __set_fixmap(idx, 0, __pgprot(0)) | |
114 | ||
115 | #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) | |
116 | ||
117 | #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) | |
118 | #define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | |
119 | #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) | |
120 | #define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE) | |
121 | ||
122 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) | |
123 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) | |
124 | ||
1da177e4 LT |
125 | extern void __this_fixmap_does_not_exist(void); |
126 | ||
127 | /* | |
128 | * 'index to address' translation. If anyone tries to use the idx | |
129 | * directly without tranlation, we catch the bug with a NULL-deference | |
130 | * kernel oops. Illegal ranges of incoming indices are caught too. | |
131 | */ | |
132 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) | |
133 | { | |
134 | /* | |
135 | * this branch gets completely eliminated after inlining, | |
136 | * except when someone tries to use fixaddr indices in an | |
137 | * illegal way. (such as mixing up address types or using | |
138 | * out-of-range indices). | |
139 | * | |
140 | * If it doesn't get removed, the linker will complain | |
141 | * loudly with a reasonably clear error message.. | |
142 | */ | |
143 | if (idx >= __end_of_fixed_addresses) | |
144 | __this_fixmap_does_not_exist(); | |
145 | ||
146 | return __fix_to_virt(idx); | |
147 | } | |
148 | ||
149 | static inline unsigned long virt_to_fix(const unsigned long vaddr) | |
150 | { | |
151 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); | |
152 | return __virt_to_fix(vaddr); | |
153 | } | |
154 | ||
155 | #endif /* !__ASSEMBLY__ */ | |
156 | #endif |