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 * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009 12 */ 13 14#ifndef _ASM_X86_FIXMAP_H 15#define _ASM_X86_FIXMAP_H 16 17#ifndef __ASSEMBLY__ 18#include <linux/kernel.h> 19#include <asm/acpi.h> 20#include <asm/apicdef.h> 21#include <asm/page.h> 22#ifdef CONFIG_X86_32 23#include <linux/threads.h> 24#include <asm/kmap_types.h> 25#else 26#include <asm/vsyscall.h> 27#endif 28 29/* 30 * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall 31 * uses fixmaps that relies on FIXADDR_TOP for proper address calculation. 32 * Because of this, FIXADDR_TOP x86 integration was left as later work. 33 */ 34#ifdef CONFIG_X86_32 35/* used by vmalloc.c, vsyscall.lds.S. 36 * 37 * Leave one empty page between vmalloc'ed areas and 38 * the start of the fixmap. 39 */ 40extern unsigned long __FIXADDR_TOP; 41#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) 42 43#define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) 44#define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) 45#else 46#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE) 47 48/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */ 49#define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL) 50#define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE) 51#endif 52 53 54/* 55 * Here we define all the compile-time 'special' virtual 56 * addresses. The point is to have a constant address at 57 * compile time, but to set the physical address only 58 * in the boot process. 59 * for x86_32: We allocate these special addresses 60 * from the end of virtual memory (0xfffff000) backwards. 61 * Also this lets us do fail-safe vmalloc(), we 62 * can guarantee that these special addresses and 63 * vmalloc()-ed addresses never overlap. 64 * 65 * These 'compile-time allocated' memory buffers are 66 * fixed-size 4k pages (or larger if used with an increment 67 * higher than 1). Use set_fixmap(idx,phys) to associate 68 * physical memory with fixmap indices. 69 * 70 * TLB entries of such buffers will not be flushed across 71 * task switches. 72 */ 73enum fixed_addresses { 74#ifdef CONFIG_X86_32 75 FIX_HOLE, 76 FIX_VDSO, 77#else 78 VSYSCALL_LAST_PAGE, 79 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE 80 + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1, 81 VSYSCALL_HPET, 82#endif 83 FIX_DBGP_BASE, 84 FIX_EARLYCON_MEM_BASE, 85#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT 86 FIX_OHCI1394_BASE, 87#endif 88#ifdef CONFIG_X86_LOCAL_APIC 89 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 90#endif 91#ifdef CONFIG_X86_IO_APIC 92 FIX_IO_APIC_BASE_0, 93 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, 94#endif 95#ifdef CONFIG_X86_VISWS_APIC 96 FIX_CO_CPU, /* Cobalt timer */ 97 FIX_CO_APIC, /* Cobalt APIC Redirection Table */ 98 FIX_LI_PCIA, /* Lithium PCI Bridge A */ 99 FIX_LI_PCIB, /* Lithium PCI Bridge B */ 100#endif 101#ifdef CONFIG_X86_F00F_BUG 102 FIX_F00F_IDT, /* Virtual mapping for IDT */ 103#endif 104#ifdef CONFIG_X86_CYCLONE_TIMER 105 FIX_CYCLONE_TIMER, /*cyclone timer register*/ 106#endif 107#ifdef CONFIG_X86_32 108 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 109 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 110#ifdef CONFIG_PCI_MMCONFIG 111 FIX_PCIE_MCFG, 112#endif 113#endif 114#ifdef CONFIG_PARAVIRT 115 FIX_PARAVIRT_BOOTMAP, 116#endif 117 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */ 118 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */ 119 __end_of_permanent_fixed_addresses, 120 /* 121 * 256 temporary boot-time mappings, used by early_ioremap(), 122 * before ioremap() is functional. 123 * 124 * If necessary we round it up to the next 256 pages boundary so 125 * that we can have a single pgd entry and a single pte table: 126 */ 127#define NR_FIX_BTMAPS 64 128#define FIX_BTMAPS_SLOTS 4 129#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 130 FIX_BTMAP_END = 131 (__end_of_permanent_fixed_addresses ^ 132 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 133 -PTRS_PER_PTE 134 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 135 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1)) 136 : __end_of_permanent_fixed_addresses, 137 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, 138#ifdef CONFIG_X86_32 139 FIX_WP_TEST, 140#endif 141#ifdef CONFIG_INTEL_TXT 142 FIX_TBOOT_BASE, 143#endif 144 __end_of_fixed_addresses 145}; 146 147 148extern void reserve_top_address(unsigned long reserve); 149 150#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 151#define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 152#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 153#define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE) 154 155extern int fixmaps_set; 156 157extern pte_t *kmap_pte; 158extern pgprot_t kmap_prot; 159extern pte_t *pkmap_page_table; 160 161void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); 162void native_set_fixmap(enum fixed_addresses idx, 163 phys_addr_t phys, pgprot_t flags); 164 165#ifndef CONFIG_PARAVIRT 166static inline void __set_fixmap(enum fixed_addresses idx, 167 phys_addr_t phys, pgprot_t flags) 168{ 169 native_set_fixmap(idx, phys, flags); 170} 171#endif 172 173#define set_fixmap(idx, phys) \ 174 __set_fixmap(idx, phys, PAGE_KERNEL) 175 176/* 177 * Some hardware wants to get fixmapped without caching. 178 */ 179#define set_fixmap_nocache(idx, phys) \ 180 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 181 182#define clear_fixmap(idx) \ 183 __set_fixmap(idx, 0, __pgprot(0)) 184 185#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 186#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 187 188extern void __this_fixmap_does_not_exist(void); 189 190/* 191 * 'index to address' translation. If anyone tries to use the idx 192 * directly without translation, we catch the bug with a NULL-deference 193 * kernel oops. Illegal ranges of incoming indices are caught too. 194 */ 195static __always_inline unsigned long fix_to_virt(const unsigned int idx) 196{ 197 /* 198 * this branch gets completely eliminated after inlining, 199 * except when someone tries to use fixaddr indices in an 200 * illegal way. (such as mixing up address types or using 201 * out-of-range indices). 202 * 203 * If it doesn't get removed, the linker will complain 204 * loudly with a reasonably clear error message.. 205 */ 206 if (idx >= __end_of_fixed_addresses) 207 __this_fixmap_does_not_exist(); 208 209 return __fix_to_virt(idx); 210} 211 212static inline unsigned long virt_to_fix(const unsigned long vaddr) 213{ 214 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 215 return __virt_to_fix(vaddr); 216} 217#endif /* !__ASSEMBLY__ */ 218#endif /* _ASM_X86_FIXMAP_H */ 219