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Linux kernel mirror (for testing)
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linux
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
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 */
22extern unsigned long __FIXADDR_TOP;
23#define FIXADDR_USER_START __fix_to_virt(FIX_VDSO)
24#define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1)
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 */
54enum fixed_addresses {
55 FIX_HOLE,
56 FIX_VDSO,
57 FIX_DBGP_BASE,
58 FIX_EARLYCON_MEM_BASE,
59#ifdef CONFIG_X86_LOCAL_APIC
60 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
61#endif
62#ifdef CONFIG_X86_IO_APIC
63 FIX_IO_APIC_BASE_0,
64 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
65#endif
66#ifdef CONFIG_X86_VISWS_APIC
67 FIX_CO_CPU, /* Cobalt timer */
68 FIX_CO_APIC, /* Cobalt APIC Redirection Table */
69 FIX_LI_PCIA, /* Lithium PCI Bridge A */
70 FIX_LI_PCIB, /* Lithium PCI Bridge B */
71#endif
72#ifdef CONFIG_X86_F00F_BUG
73 FIX_F00F_IDT, /* Virtual mapping for IDT */
74#endif
75#ifdef CONFIG_X86_CYCLONE_TIMER
76 FIX_CYCLONE_TIMER, /*cyclone timer register*/
77#endif
78#ifdef CONFIG_HIGHMEM
79 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
80 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
81#endif
82#ifdef CONFIG_ACPI
83 FIX_ACPI_BEGIN,
84 FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1,
85#endif
86#ifdef CONFIG_PCI_MMCONFIG
87 FIX_PCIE_MCFG,
88#endif
89#ifdef CONFIG_PARAVIRT
90 FIX_PARAVIRT_BOOTMAP,
91#endif
92 __end_of_permanent_fixed_addresses,
93 /*
94 * 256 temporary boot-time mappings, used by early_ioremap(),
95 * before ioremap() is functional.
96 *
97 * We round it up to the next 512 pages boundary so that we
98 * can have a single pgd entry and a single pte table:
99 */
100#define NR_FIX_BTMAPS 64
101#define FIX_BTMAPS_NESTING 4
102 FIX_BTMAP_END =
103 __end_of_permanent_fixed_addresses + 512 -
104 (__end_of_permanent_fixed_addresses & 511),
105 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
106 FIX_WP_TEST,
107#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
108 FIX_OHCI1394_BASE,
109#endif
110 __end_of_fixed_addresses
111};
112
113extern void __set_fixmap (enum fixed_addresses idx,
114 unsigned long phys, pgprot_t flags);
115extern void reserve_top_address(unsigned long reserve);
116
117#define set_fixmap(idx, phys) \
118 __set_fixmap(idx, phys, PAGE_KERNEL)
119/*
120 * Some hardware wants to get fixmapped without caching.
121 */
122#define set_fixmap_nocache(idx, phys) \
123 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
124
125#define clear_fixmap(idx) \
126 __set_fixmap(idx, 0, __pgprot(0))
127
128#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
129
130#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
131#define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
132#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
133#define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE)
134
135#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
136#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
137
138extern void __this_fixmap_does_not_exist(void);
139
140/*
141 * 'index to address' translation. If anyone tries to use the idx
142 * directly without tranlation, we catch the bug with a NULL-deference
143 * kernel oops. Illegal ranges of incoming indices are caught too.
144 */
145static __always_inline unsigned long fix_to_virt(const unsigned int idx)
146{
147 /*
148 * this branch gets completely eliminated after inlining,
149 * except when someone tries to use fixaddr indices in an
150 * illegal way. (such as mixing up address types or using
151 * out-of-range indices).
152 *
153 * If it doesn't get removed, the linker will complain
154 * loudly with a reasonably clear error message..
155 */
156 if (idx >= __end_of_fixed_addresses)
157 __this_fixmap_does_not_exist();
158
159 return __fix_to_virt(idx);
160}
161
162static inline unsigned long virt_to_fix(const unsigned long vaddr)
163{
164 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
165 return __virt_to_fix(vaddr);
166}
167
168#endif /* !__ASSEMBLY__ */
169#endif