source: trunk/packages/xen-3.1/xen-3.1/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/fixmap.h @ 34

Last change on this file since 34 was 34, checked in by hartmans, 18 years ago

Add xen and xen-common

File size: 3.3 KB
Line 
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#include <asm/vsyscall32.h>
19#include <asm/acpi.h>
20
21/*
22 * Here we define all the compile-time 'special' virtual
23 * addresses. The point is to have a constant address at
24 * compile time, but to set the physical address only
25 * in the boot process.
26 *
27 * these 'compile-time allocated' memory buffers are
28 * fixed-size 4k pages. (or larger if used with an increment
29 * highger than 1) use fixmap_set(idx,phys) to associate
30 * physical memory with fixmap indices.
31 *
32 * TLB entries of such buffers will not be flushed across
33 * task switches.
34 */
35
36enum fixed_addresses {
37        VSYSCALL_LAST_PAGE,
38        VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
39        VSYSCALL_HPET,
40        FIX_HPET_BASE,
41#ifdef CONFIG_X86_LOCAL_APIC
42        FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
43#endif
44#ifdef CONFIG_X86_IO_APIC
45        FIX_IO_APIC_BASE_0,
46        FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
47#endif
48#ifdef CONFIG_ACPI
49        FIX_ACPI_BEGIN,
50        FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1,
51#endif
52        FIX_SHARED_INFO,
53#define NR_FIX_ISAMAPS  256
54        FIX_ISAMAP_END,
55        FIX_ISAMAP_BEGIN = FIX_ISAMAP_END + NR_FIX_ISAMAPS - 1,
56        __end_of_permanent_fixed_addresses,
57        /* temporary boot-time mappings, used before ioremap() is functional */
58#define NR_FIX_BTMAPS   16
59        FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
60        FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1,
61        __end_of_fixed_addresses
62};
63
64extern void __set_fixmap (enum fixed_addresses idx,
65                                        unsigned long phys, pgprot_t flags);
66
67#define set_fixmap(idx, phys) \
68                __set_fixmap(idx, phys, PAGE_KERNEL)
69/*
70 * Some hardware wants to get fixmapped without caching.
71 */
72#define set_fixmap_nocache(idx, phys) \
73                __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
74
75#define clear_fixmap(idx) \
76                __set_fixmap(idx, 0, __pgprot(0))
77
78#define FIXADDR_TOP     (VSYSCALL_END-PAGE_SIZE)
79#define FIXADDR_SIZE    (__end_of_fixed_addresses << PAGE_SHIFT)
80#define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
81
82/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
83#define FIXADDR_USER_START      ((unsigned long)VSYSCALL32_VSYSCALL)
84#define FIXADDR_USER_END        (FIXADDR_USER_START + PAGE_SIZE)
85
86#define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
87
88extern void __this_fixmap_does_not_exist(void);
89
90/*
91 * 'index to address' translation. If anyone tries to use the idx
92 * directly without translation, we catch the bug with a NULL-deference
93 * kernel oops. Illegal ranges of incoming indices are caught too.
94 */
95static __always_inline unsigned long fix_to_virt(const unsigned int idx)
96{
97        /*
98         * this branch gets completely eliminated after inlining,
99         * except when someone tries to use fixaddr indices in an
100         * illegal way. (such as mixing up address types or using
101         * out-of-range indices).
102         *
103         * If it doesn't get removed, the linker will complain
104         * loudly with a reasonably clear error message..
105         */
106        if (idx >= __end_of_fixed_addresses)
107                __this_fixmap_does_not_exist();
108
109        return __fix_to_virt(idx);
110}
111
112#endif
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