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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
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 */
22#define __FIXADDR_TOP 0xfffff000
23
24#ifndef __ASSEMBLY__
25#include <linux/kernel.h>
26#include <asm/acpi.h>
27#include <asm/apicdef.h>
28#include <asm/page.h>
29#ifdef CONFIG_HIGHMEM
30#include <linux/threads.h>
31#include <asm/kmap_types.h>
32#endif
33
34/*
35 * Here we define all the compile-time 'special' virtual
36 * addresses. The point is to have a constant address at
37 * compile time, but to set the physical address only
38 * in the boot process. We allocate these special addresses
39 * from the end of virtual memory (0xfffff000) backwards.
40 * Also this lets us do fail-safe vmalloc(), we
41 * can guarantee that these special addresses and
42 * vmalloc()-ed addresses never overlap.
43 *
44 * these 'compile-time allocated' memory buffers are
45 * fixed-size 4k pages. (or larger if used with an increment
46 * highger than 1) use fixmap_set(idx,phys) to associate
47 * physical memory with fixmap indices.
48 *
49 * TLB entries of such buffers will not be flushed across
50 * task switches.
51 */
52enum fixed_addresses {
53 FIX_HOLE,
Ingo Molnare6e54942006-06-27 02:53:50 -070054 FIX_VDSO,
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#ifdef CONFIG_X86_LOCAL_APIC
56 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
57#endif
58#ifdef CONFIG_X86_IO_APIC
59 FIX_IO_APIC_BASE_0,
60 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
61#endif
62#ifdef CONFIG_X86_VISWS_APIC
63 FIX_CO_CPU, /* Cobalt timer */
64 FIX_CO_APIC, /* Cobalt APIC Redirection Table */
65 FIX_LI_PCIA, /* Lithium PCI Bridge A */
66 FIX_LI_PCIB, /* Lithium PCI Bridge B */
67#endif
68#ifdef CONFIG_X86_F00F_BUG
69 FIX_F00F_IDT, /* Virtual mapping for IDT */
70#endif
71#ifdef CONFIG_X86_CYCLONE_TIMER
72 FIX_CYCLONE_TIMER, /*cyclone timer register*/
73#endif
74#ifdef CONFIG_HIGHMEM
75 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
76 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
77#endif
Len Brown888ba6c2005-08-24 12:07:20 -040078#ifdef CONFIG_ACPI
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 FIX_ACPI_BEGIN,
80 FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1,
81#endif
82#ifdef CONFIG_PCI_MMCONFIG
83 FIX_PCIE_MCFG,
84#endif
85 __end_of_permanent_fixed_addresses,
86 /* temporary boot-time mappings, used before ioremap() is functional */
87#define NR_FIX_BTMAPS 16
88 FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
89 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1,
90 FIX_WP_TEST,
91 __end_of_fixed_addresses
92};
93
94extern void __set_fixmap (enum fixed_addresses idx,
95 unsigned long phys, pgprot_t flags);
96
97#define set_fixmap(idx, phys) \
98 __set_fixmap(idx, phys, PAGE_KERNEL)
99/*
100 * Some hardware wants to get fixmapped without caching.
101 */
102#define set_fixmap_nocache(idx, phys) \
103 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
104
105#define clear_fixmap(idx) \
106 __set_fixmap(idx, 0, __pgprot(0))
107
108#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
109
110#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
111#define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
112#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
113#define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE)
114
115#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
116#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118extern void __this_fixmap_does_not_exist(void);
119
120/*
121 * 'index to address' translation. If anyone tries to use the idx
122 * directly without tranlation, we catch the bug with a NULL-deference
123 * kernel oops. Illegal ranges of incoming indices are caught too.
124 */
125static __always_inline unsigned long fix_to_virt(const unsigned int idx)
126{
127 /*
128 * this branch gets completely eliminated after inlining,
129 * except when someone tries to use fixaddr indices in an
130 * illegal way. (such as mixing up address types or using
131 * out-of-range indices).
132 *
133 * If it doesn't get removed, the linker will complain
134 * loudly with a reasonably clear error message..
135 */
136 if (idx >= __end_of_fixed_addresses)
137 __this_fixmap_does_not_exist();
138
139 return __fix_to_virt(idx);
140}
141
142static inline unsigned long virt_to_fix(const unsigned long vaddr)
143{
144 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
145 return __virt_to_fix(vaddr);
146}
147
148#endif /* !__ASSEMBLY__ */
149#endif