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_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 #ifdef CONFIG_X86_MRST 120 FIX_LNW_VRTC, 121 #endif 122 __end_of_permanent_fixed_addresses, 123 124 /* 125 * 256 temporary boot-time mappings, used by early_ioremap(), 126 * before ioremap() is functional. 127 * 128 * If necessary we round it up to the next 256 pages boundary so 129 * that we can have a single pgd entry and a single pte table: 130 */ 131 #define NR_FIX_BTMAPS 64 132 #define FIX_BTMAPS_SLOTS 4 133 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 134 FIX_BTMAP_END = 135 (__end_of_permanent_fixed_addresses ^ 136 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 137 -PTRS_PER_PTE 138 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 139 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1)) 140 : __end_of_permanent_fixed_addresses, 141 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, 142 #ifdef CONFIG_X86_32 143 FIX_WP_TEST, 144 #endif 145 #ifdef CONFIG_INTEL_TXT 146 FIX_TBOOT_BASE, 147 #endif 148 __end_of_fixed_addresses 149 }; 150 151 152 extern void reserve_top_address(unsigned long reserve); 153 154 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 155 #define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 156 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 157 #define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE) 158 159 extern int fixmaps_set; 160 161 extern pte_t *kmap_pte; 162 extern pgprot_t kmap_prot; 163 extern pte_t *pkmap_page_table; 164 165 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); 166 void native_set_fixmap(enum fixed_addresses idx, 167 phys_addr_t phys, pgprot_t flags); 168 169 #ifndef CONFIG_PARAVIRT 170 static inline void __set_fixmap(enum fixed_addresses idx, 171 phys_addr_t phys, pgprot_t flags) 172 { 173 native_set_fixmap(idx, phys, flags); 174 } 175 #endif 176 177 #define set_fixmap(idx, phys) \ 178 __set_fixmap(idx, phys, PAGE_KERNEL) 179 180 /* 181 * Some hardware wants to get fixmapped without caching. 182 */ 183 #define set_fixmap_nocache(idx, phys) \ 184 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 185 186 #define clear_fixmap(idx) \ 187 __set_fixmap(idx, 0, __pgprot(0)) 188 189 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 190 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 191 192 extern void __this_fixmap_does_not_exist(void); 193 194 /* 195 * 'index to address' translation. If anyone tries to use the idx 196 * directly without translation, we catch the bug with a NULL-deference 197 * kernel oops. Illegal ranges of incoming indices are caught too. 198 */ 199 static __always_inline unsigned long fix_to_virt(const unsigned int idx) 200 { 201 /* 202 * this branch gets completely eliminated after inlining, 203 * except when someone tries to use fixaddr indices in an 204 * illegal way. (such as mixing up address types or using 205 * out-of-range indices). 206 * 207 * If it doesn't get removed, the linker will complain 208 * loudly with a reasonably clear error message.. 209 */ 210 if (idx >= __end_of_fixed_addresses) 211 __this_fixmap_does_not_exist(); 212 213 return __fix_to_virt(idx); 214 } 215 216 static inline unsigned long virt_to_fix(const unsigned long vaddr) 217 { 218 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 219 return __virt_to_fix(vaddr); 220 } 221 222 /* Return an pointer with offset calculated */ 223 static __always_inline unsigned long 224 __set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 225 { 226 __set_fixmap(idx, phys, flags); 227 return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1)); 228 } 229 230 #define set_fixmap_offset(idx, phys) \ 231 __set_fixmap_offset(idx, phys, PAGE_KERNEL) 232 233 #define set_fixmap_offset_nocache(idx, phys) \ 234 __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE) 235 236 #endif /* !__ASSEMBLY__ */ 237 #endif /* _ASM_X86_FIXMAP_H */ 238