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#ifdef CONFIG_X86_LOCAL_APIC 58 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 59#endif 60#ifdef CONFIG_X86_IO_APIC 61 FIX_IO_APIC_BASE_0, 62 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1, 63#endif 64#ifdef CONFIG_X86_VISWS_APIC 65 FIX_CO_CPU, /* Cobalt timer */ 66 FIX_CO_APIC, /* Cobalt APIC Redirection Table */ 67 FIX_LI_PCIA, /* Lithium PCI Bridge A */ 68 FIX_LI_PCIB, /* Lithium PCI Bridge B */ 69#endif 70#ifdef CONFIG_X86_F00F_BUG 71 FIX_F00F_IDT, /* Virtual mapping for IDT */ 72#endif 73#ifdef CONFIG_X86_CYCLONE_TIMER 74 FIX_CYCLONE_TIMER, /*cyclone timer register*/ 75#endif 76#ifdef CONFIG_HIGHMEM 77 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 78 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 79#endif 80#ifdef CONFIG_ACPI 81 FIX_ACPI_BEGIN, 82 FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, 83#endif 84#ifdef CONFIG_PCI_MMCONFIG 85 FIX_PCIE_MCFG, 86#endif 87#ifdef CONFIG_PARAVIRT 88 FIX_PARAVIRT_BOOTMAP, 89#endif 90 __end_of_permanent_fixed_addresses, 91 /* temporary boot-time mappings, used before ioremap() is functional */ 92#define NR_FIX_BTMAPS 16 93 FIX_BTMAP_END = __end_of_permanent_fixed_addresses, 94 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1, 95 FIX_WP_TEST, 96 __end_of_fixed_addresses 97}; 98 99extern void __set_fixmap (enum fixed_addresses idx, 100 unsigned long phys, pgprot_t flags); 101extern void reserve_top_address(unsigned long reserve); 102 103#define set_fixmap(idx, phys) \ 104 __set_fixmap(idx, phys, PAGE_KERNEL) 105/* 106 * Some hardware wants to get fixmapped without caching. 107 */ 108#define set_fixmap_nocache(idx, phys) \ 109 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 110 111#define clear_fixmap(idx) \ 112 __set_fixmap(idx, 0, __pgprot(0)) 113 114#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) 115 116#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 117#define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 118#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) 119#define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE) 120 121#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 122#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 123 124extern void __this_fixmap_does_not_exist(void); 125 126/* 127 * 'index to address' translation. If anyone tries to use the idx 128 * directly without tranlation, we catch the bug with a NULL-deference 129 * kernel oops. Illegal ranges of incoming indices are caught too. 130 */ 131static __always_inline unsigned long fix_to_virt(const unsigned int idx) 132{ 133 /* 134 * this branch gets completely eliminated after inlining, 135 * except when someone tries to use fixaddr indices in an 136 * illegal way. (such as mixing up address types or using 137 * out-of-range indices). 138 * 139 * If it doesn't get removed, the linker will complain 140 * loudly with a reasonably clear error message.. 141 */ 142 if (idx >= __end_of_fixed_addresses) 143 __this_fixmap_does_not_exist(); 144 145 return __fix_to_virt(idx); 146} 147 148static inline unsigned long virt_to_fix(const unsigned long vaddr) 149{ 150 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 151 return __virt_to_fix(vaddr); 152} 153 154#endif /* !__ASSEMBLY__ */ 155#endif 156