ia64/linux-2.6.18-xen.hg

view include/asm-i386/fixmap.h @ 20:cb5094f46707

Imported patch fixaddr-top.patch from xen-unstable.hg 15200:bd3d6b4c52ec
author Ian Campbell <ian.campbell@xensource.com>
date Mon Jun 04 10:05:24 2007 +0100 (2007-06-04)
parents 831230e53067
children
line source
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 */
13 #ifndef _ASM_FIXMAP_H
14 #define _ASM_FIXMAP_H
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 extern unsigned long __FIXADDR_TOP;
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
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 */
52 enum fixed_addresses {
53 FIX_HOLE,
54 FIX_VDSO,
55 #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
78 #ifdef CONFIG_ACPI
79 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 };
94 extern void __set_fixmap (enum fixed_addresses idx,
95 unsigned long phys, pgprot_t flags);
97 extern void set_fixaddr_top(unsigned long top);
99 #define set_fixmap(idx, phys) \
100 __set_fixmap(idx, phys, PAGE_KERNEL)
101 /*
102 * Some hardware wants to get fixmapped without caching.
103 */
104 #define set_fixmap_nocache(idx, phys) \
105 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
107 #define clear_fixmap(idx) \
108 __set_fixmap(idx, 0, __pgprot(0))
110 #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
112 #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
113 #define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
114 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
115 #define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE)
117 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
118 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
120 extern void __this_fixmap_does_not_exist(void);
122 /*
123 * 'index to address' translation. If anyone tries to use the idx
124 * directly without tranlation, we catch the bug with a NULL-deference
125 * kernel oops. Illegal ranges of incoming indices are caught too.
126 */
127 static __always_inline unsigned long fix_to_virt(const unsigned int idx)
128 {
129 /*
130 * this branch gets completely eliminated after inlining,
131 * except when someone tries to use fixaddr indices in an
132 * illegal way. (such as mixing up address types or using
133 * out-of-range indices).
134 *
135 * If it doesn't get removed, the linker will complain
136 * loudly with a reasonably clear error message..
137 */
138 if (idx >= __end_of_fixed_addresses)
139 __this_fixmap_does_not_exist();
141 return __fix_to_virt(idx);
142 }
144 static inline unsigned long virt_to_fix(const unsigned long vaddr)
145 {
146 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
147 return __virt_to_fix(vaddr);
148 }
150 #endif /* !__ASSEMBLY__ */
151 #endif