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 #ifdef CONFIG_PARAVIRT_CLOCK 85 PVCLOCK_FIXMAP_BEGIN, 86 PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1, 87 #endif 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 FIX_RO_IDT, /* Virtual mapping for read-only IDT */ 108 #ifdef CONFIG_X86_32 109 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 110 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 111 #ifdef CONFIG_PCI_MMCONFIG 112 FIX_PCIE_MCFG, 113 #endif 114 #endif 115 #ifdef CONFIG_PARAVIRT 116 FIX_PARAVIRT_BOOTMAP, 117 #endif 118 FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */ 119 FIX_TEXT_POKE0, /* first page is last, because allocation is backward */ 120 #ifdef CONFIG_X86_INTEL_MID 121 FIX_LNW_VRTC, 122 #endif 123 __end_of_permanent_fixed_addresses, 124 125 /* 126 * 256 temporary boot-time mappings, used by early_ioremap(), 127 * before ioremap() is functional. 128 * 129 * If necessary we round it up to the next 256 pages boundary so 130 * that we can have a single pgd entry and a single pte table: 131 */ 132 #define NR_FIX_BTMAPS 64 133 #define FIX_BTMAPS_SLOTS 4 134 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 135 FIX_BTMAP_END = 136 (__end_of_permanent_fixed_addresses ^ 137 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 138 -PTRS_PER_PTE 139 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 140 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1)) 141 : __end_of_permanent_fixed_addresses, 142 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, 143 #ifdef CONFIG_X86_32 144 FIX_WP_TEST, 145 #endif 146 #ifdef CONFIG_INTEL_TXT 147 FIX_TBOOT_BASE, 148 #endif 149 __end_of_fixed_addresses 150 }; 151 152 153 extern void reserve_top_address(unsigned long reserve); 154 155 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 156 #define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 157 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 158 #define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE) 159 160 extern int fixmaps_set; 161 162 extern pte_t *kmap_pte; 163 extern pgprot_t kmap_prot; 164 extern pte_t *pkmap_page_table; 165 166 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); 167 void native_set_fixmap(enum fixed_addresses idx, 168 phys_addr_t phys, pgprot_t flags); 169 170 #ifndef CONFIG_PARAVIRT 171 static inline void __set_fixmap(enum fixed_addresses idx, 172 phys_addr_t phys, pgprot_t flags) 173 { 174 native_set_fixmap(idx, phys, flags); 175 } 176 #endif 177 178 #define set_fixmap(idx, phys) \ 179 __set_fixmap(idx, phys, PAGE_KERNEL) 180 181 /* 182 * Some hardware wants to get fixmapped without caching. 183 */ 184 #define set_fixmap_nocache(idx, phys) \ 185 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 186 187 #define clear_fixmap(idx) \ 188 __set_fixmap(idx, 0, __pgprot(0)) 189 190 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 191 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 192 193 extern void __this_fixmap_does_not_exist(void); 194 195 /* 196 * 'index to address' translation. If anyone tries to use the idx 197 * directly without translation, we catch the bug with a NULL-deference 198 * kernel oops. Illegal ranges of incoming indices are caught too. 199 */ 200 static __always_inline unsigned long fix_to_virt(const unsigned int idx) 201 { 202 /* 203 * this branch gets completely eliminated after inlining, 204 * except when someone tries to use fixaddr indices in an 205 * illegal way. (such as mixing up address types or using 206 * out-of-range indices). 207 * 208 * If it doesn't get removed, the linker will complain 209 * loudly with a reasonably clear error message.. 210 */ 211 if (idx >= __end_of_fixed_addresses) 212 __this_fixmap_does_not_exist(); 213 214 return __fix_to_virt(idx); 215 } 216 217 static inline unsigned long virt_to_fix(const unsigned long vaddr) 218 { 219 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 220 return __virt_to_fix(vaddr); 221 } 222 223 /* Return an pointer with offset calculated */ 224 static __always_inline unsigned long 225 __set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 226 { 227 __set_fixmap(idx, phys, flags); 228 return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1)); 229 } 230 231 #define set_fixmap_offset(idx, phys) \ 232 __set_fixmap_offset(idx, phys, PAGE_KERNEL) 233 234 #define set_fixmap_offset_nocache(idx, phys) \ 235 __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE) 236 237 #endif /* !__ASSEMBLY__ */ 238 #endif /* _ASM_X86_FIXMAP_H */ 239