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 #include <asm/pvclock.h> 23 #ifdef CONFIG_X86_32 24 #include <linux/threads.h> 25 #include <asm/kmap_types.h> 26 #else 27 #include <asm/vsyscall.h> 28 #endif 29 30 /* 31 * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall 32 * uses fixmaps that relies on FIXADDR_TOP for proper address calculation. 33 * Because of this, FIXADDR_TOP x86 integration was left as later work. 34 */ 35 #ifdef CONFIG_X86_32 36 /* used by vmalloc.c, vsyscall.lds.S. 37 * 38 * Leave one empty page between vmalloc'ed areas and 39 * the start of the fixmap. 40 */ 41 extern unsigned long __FIXADDR_TOP; 42 #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) 43 44 #define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) 45 #define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) 46 #else 47 #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE) 48 49 /* Only covers 32bit vsyscalls currently. Need another set for 64bit. */ 50 #define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL) 51 #define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE) 52 #endif 53 54 55 /* 56 * Here we define all the compile-time 'special' virtual 57 * addresses. The point is to have a constant address at 58 * compile time, but to set the physical address only 59 * in the boot process. 60 * for x86_32: We allocate these special addresses 61 * from the end of virtual memory (0xfffff000) backwards. 62 * Also this lets us do fail-safe vmalloc(), we 63 * can guarantee that these special addresses and 64 * vmalloc()-ed addresses never overlap. 65 * 66 * These 'compile-time allocated' memory buffers are 67 * fixed-size 4k pages (or larger if used with an increment 68 * higher than 1). Use set_fixmap(idx,phys) to associate 69 * physical memory with fixmap indices. 70 * 71 * TLB entries of such buffers will not be flushed across 72 * task switches. 73 */ 74 enum fixed_addresses { 75 #ifdef CONFIG_X86_32 76 FIX_HOLE, 77 FIX_VDSO, 78 #else 79 VSYSCALL_LAST_PAGE, 80 VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE 81 + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1, 82 VVAR_PAGE, 83 VSYSCALL_HPET, 84 #endif 85 #ifdef CONFIG_PARAVIRT_CLOCK 86 PVCLOCK_FIXMAP_BEGIN, 87 PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1, 88 #endif 89 FIX_DBGP_BASE, 90 FIX_EARLYCON_MEM_BASE, 91 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT 92 FIX_OHCI1394_BASE, 93 #endif 94 #ifdef CONFIG_X86_LOCAL_APIC 95 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 96 #endif 97 #ifdef CONFIG_X86_IO_APIC 98 FIX_IO_APIC_BASE_0, 99 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, 100 #endif 101 #ifdef CONFIG_X86_VISWS_APIC 102 FIX_CO_CPU, /* Cobalt timer */ 103 FIX_CO_APIC, /* Cobalt APIC Redirection Table */ 104 FIX_LI_PCIA, /* Lithium PCI Bridge A */ 105 FIX_LI_PCIB, /* Lithium PCI Bridge B */ 106 #endif 107 #ifdef CONFIG_X86_F00F_BUG 108 FIX_F00F_IDT, /* Virtual mapping for IDT */ 109 #endif 110 #ifdef CONFIG_X86_CYCLONE_TIMER 111 FIX_CYCLONE_TIMER, /*cyclone timer register*/ 112 #endif 113 #ifdef CONFIG_X86_32 114 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 115 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 116 #ifdef CONFIG_PCI_MMCONFIG 117 FIX_PCIE_MCFG, 118 #endif 119 #endif 120 #ifdef CONFIG_PARAVIRT 121 FIX_PARAVIRT_BOOTMAP, 122 #endif 123 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */ 124 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */ 125 #ifdef CONFIG_X86_INTEL_MID 126 FIX_LNW_VRTC, 127 #endif 128 __end_of_permanent_fixed_addresses, 129 130 /* 131 * 256 temporary boot-time mappings, used by early_ioremap(), 132 * before ioremap() is functional. 133 * 134 * If necessary we round it up to the next 256 pages boundary so 135 * that we can have a single pgd entry and a single pte table: 136 */ 137 #define NR_FIX_BTMAPS 64 138 #define FIX_BTMAPS_SLOTS 4 139 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 140 FIX_BTMAP_END = 141 (__end_of_permanent_fixed_addresses ^ 142 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 143 -PTRS_PER_PTE 144 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 145 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1)) 146 : __end_of_permanent_fixed_addresses, 147 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, 148 #ifdef CONFIG_X86_32 149 FIX_WP_TEST, 150 #endif 151 #ifdef CONFIG_INTEL_TXT 152 FIX_TBOOT_BASE, 153 #endif 154 __end_of_fixed_addresses 155 }; 156 157 158 extern void reserve_top_address(unsigned long reserve); 159 160 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 161 #define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 162 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 163 #define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE) 164 165 extern int fixmaps_set; 166 167 extern pte_t *kmap_pte; 168 extern pgprot_t kmap_prot; 169 extern pte_t *pkmap_page_table; 170 171 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); 172 void native_set_fixmap(enum fixed_addresses idx, 173 phys_addr_t phys, pgprot_t flags); 174 175 #ifndef CONFIG_PARAVIRT 176 static inline void __set_fixmap(enum fixed_addresses idx, 177 phys_addr_t phys, pgprot_t flags) 178 { 179 native_set_fixmap(idx, phys, flags); 180 } 181 #endif 182 183 #define set_fixmap(idx, phys) \ 184 __set_fixmap(idx, phys, PAGE_KERNEL) 185 186 /* 187 * Some hardware wants to get fixmapped without caching. 188 */ 189 #define set_fixmap_nocache(idx, phys) \ 190 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 191 192 #define clear_fixmap(idx) \ 193 __set_fixmap(idx, 0, __pgprot(0)) 194 195 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 196 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 197 198 extern void __this_fixmap_does_not_exist(void); 199 200 /* 201 * 'index to address' translation. If anyone tries to use the idx 202 * directly without translation, we catch the bug with a NULL-deference 203 * kernel oops. Illegal ranges of incoming indices are caught too. 204 */ 205 static __always_inline unsigned long fix_to_virt(const unsigned int idx) 206 { 207 /* 208 * this branch gets completely eliminated after inlining, 209 * except when someone tries to use fixaddr indices in an 210 * illegal way. (such as mixing up address types or using 211 * out-of-range indices). 212 * 213 * If it doesn't get removed, the linker will complain 214 * loudly with a reasonably clear error message.. 215 */ 216 if (idx >= __end_of_fixed_addresses) 217 __this_fixmap_does_not_exist(); 218 219 return __fix_to_virt(idx); 220 } 221 222 static inline unsigned long virt_to_fix(const unsigned long vaddr) 223 { 224 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 225 return __virt_to_fix(vaddr); 226 } 227 228 /* Return an pointer with offset calculated */ 229 static __always_inline unsigned long 230 __set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 231 { 232 __set_fixmap(idx, phys, flags); 233 return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1)); 234 } 235 236 #define set_fixmap_offset(idx, phys) \ 237 __set_fixmap_offset(idx, phys, PAGE_KERNEL) 238 239 #define set_fixmap_offset_nocache(idx, phys) \ 240 __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE) 241 242 #endif /* !__ASSEMBLY__ */ 243 #endif /* _ASM_X86_FIXMAP_H */ 244