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 */ 40 extern 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 */ 73 enum 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_X86_LOCAL_APIC 86 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 87 #endif 88 #ifdef CONFIG_X86_IO_APIC 89 FIX_IO_APIC_BASE_0, 90 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, 91 #endif 92 #ifdef CONFIG_X86_VISWS_APIC 93 FIX_CO_CPU, /* Cobalt timer */ 94 FIX_CO_APIC, /* Cobalt APIC Redirection Table */ 95 FIX_LI_PCIA, /* Lithium PCI Bridge A */ 96 FIX_LI_PCIB, /* Lithium PCI Bridge B */ 97 #endif 98 #ifdef CONFIG_X86_F00F_BUG 99 FIX_F00F_IDT, /* Virtual mapping for IDT */ 100 #endif 101 #ifdef CONFIG_X86_CYCLONE_TIMER 102 FIX_CYCLONE_TIMER, /*cyclone timer register*/ 103 #endif 104 #ifdef CONFIG_X86_32 105 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 106 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 107 #ifdef CONFIG_PCI_MMCONFIG 108 FIX_PCIE_MCFG, 109 #endif 110 #endif 111 #ifdef CONFIG_PARAVIRT 112 FIX_PARAVIRT_BOOTMAP, 113 #endif 114 __end_of_permanent_fixed_addresses, 115 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT 116 FIX_OHCI1394_BASE, 117 #endif 118 /* 119 * 256 temporary boot-time mappings, used by early_ioremap(), 120 * before ioremap() is functional. 121 * 122 * We round it up to the next 256 pages boundary so that we 123 * can have a single pgd entry and a single pte table: 124 */ 125 #define NR_FIX_BTMAPS 64 126 #define FIX_BTMAPS_SLOTS 4 127 FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 256 - 128 (__end_of_permanent_fixed_addresses & 255), 129 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_SLOTS - 1, 130 #ifdef CONFIG_X86_32 131 FIX_WP_TEST, 132 #endif 133 __end_of_fixed_addresses 134 }; 135 136 137 extern void reserve_top_address(unsigned long reserve); 138 139 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 140 #define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 141 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 142 #define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE) 143 144 extern int fixmaps_set; 145 146 extern pte_t *kmap_pte; 147 extern pgprot_t kmap_prot; 148 extern pte_t *pkmap_page_table; 149 150 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); 151 void native_set_fixmap(enum fixed_addresses idx, 152 unsigned long phys, pgprot_t flags); 153 154 #ifndef CONFIG_PARAVIRT 155 static inline void __set_fixmap(enum fixed_addresses idx, 156 unsigned long phys, pgprot_t flags) 157 { 158 native_set_fixmap(idx, phys, flags); 159 } 160 #endif 161 162 #define set_fixmap(idx, phys) \ 163 __set_fixmap(idx, phys, PAGE_KERNEL) 164 165 /* 166 * Some hardware wants to get fixmapped without caching. 167 */ 168 #define set_fixmap_nocache(idx, phys) \ 169 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 170 171 #define clear_fixmap(idx) \ 172 __set_fixmap(idx, 0, __pgprot(0)) 173 174 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 175 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 176 177 extern void __this_fixmap_does_not_exist(void); 178 179 /* 180 * 'index to address' translation. If anyone tries to use the idx 181 * directly without translation, we catch the bug with a NULL-deference 182 * kernel oops. Illegal ranges of incoming indices are caught too. 183 */ 184 static __always_inline unsigned long fix_to_virt(const unsigned int idx) 185 { 186 /* 187 * this branch gets completely eliminated after inlining, 188 * except when someone tries to use fixaddr indices in an 189 * illegal way. (such as mixing up address types or using 190 * out-of-range indices). 191 * 192 * If it doesn't get removed, the linker will complain 193 * loudly with a reasonably clear error message.. 194 */ 195 if (idx >= __end_of_fixed_addresses) 196 __this_fixmap_does_not_exist(); 197 198 return __fix_to_virt(idx); 199 } 200 201 static inline unsigned long virt_to_fix(const unsigned long vaddr) 202 { 203 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 204 return __virt_to_fix(vaddr); 205 } 206 #endif /* !__ASSEMBLY__ */ 207 #endif /* _ASM_X86_FIXMAP_H */ 208