1 #ifndef _ASM_X86_SEGMENT_H 2 #define _ASM_X86_SEGMENT_H 3 4 /* Constructor for a conventional segment GDT (or LDT) entry */ 5 /* This is a macro so it can be used in initializers */ 6 #define GDT_ENTRY(flags, base, limit) \ 7 ((((base) & 0xff000000ULL) << (56-24)) | \ 8 (((flags) & 0x0000f0ffULL) << 40) | \ 9 (((limit) & 0x000f0000ULL) << (48-16)) | \ 10 (((base) & 0x00ffffffULL) << 16) | \ 11 (((limit) & 0x0000ffffULL))) 12 13 /* Simple and small GDT entries for booting only */ 14 15 #define GDT_ENTRY_BOOT_CS 2 16 #define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8) 17 18 #define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1) 19 #define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) 20 21 #define GDT_ENTRY_BOOT_TSS (GDT_ENTRY_BOOT_CS + 2) 22 #define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8) 23 24 #ifdef CONFIG_X86_32 25 /* 26 * The layout of the per-CPU GDT under Linux: 27 * 28 * 0 - null 29 * 1 - reserved 30 * 2 - reserved 31 * 3 - reserved 32 * 33 * 4 - unused <==== new cacheline 34 * 5 - unused 35 * 36 * ------- start of TLS (Thread-Local Storage) segments: 37 * 38 * 6 - TLS segment #1 [ glibc's TLS segment ] 39 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ] 40 * 8 - TLS segment #3 41 * 9 - reserved 42 * 10 - reserved 43 * 11 - reserved 44 * 45 * ------- start of kernel segments: 46 * 47 * 12 - kernel code segment <==== new cacheline 48 * 13 - kernel data segment 49 * 14 - default user CS 50 * 15 - default user DS 51 * 16 - TSS 52 * 17 - LDT 53 * 18 - PNPBIOS support (16->32 gate) 54 * 19 - PNPBIOS support 55 * 20 - PNPBIOS support 56 * 21 - PNPBIOS support 57 * 22 - PNPBIOS support 58 * 23 - APM BIOS support 59 * 24 - APM BIOS support 60 * 25 - APM BIOS support 61 * 62 * 26 - ESPFIX small SS 63 * 27 - per-cpu [ offset to per-cpu data area ] 64 * 28 - unused 65 * 29 - unused 66 * 30 - unused 67 * 31 - TSS for double fault handler 68 */ 69 #define GDT_ENTRY_TLS_MIN 6 70 #define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1) 71 72 #define GDT_ENTRY_DEFAULT_USER_CS 14 73 74 #define GDT_ENTRY_DEFAULT_USER_DS 15 75 76 #define GDT_ENTRY_KERNEL_BASE 12 77 78 #define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE + 0) 79 80 #define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE + 1) 81 82 #define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE + 4) 83 #define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE + 5) 84 85 #define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 6) 86 #define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 11) 87 88 #define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14) 89 #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8) 90 91 #define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE + 15) 92 #ifdef CONFIG_SMP 93 #define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8) 94 #else 95 #define __KERNEL_PERCPU 0 96 #endif 97 98 #define GDT_ENTRY_DOUBLEFAULT_TSS 31 99 100 /* 101 * The GDT has 32 entries 102 */ 103 #define GDT_ENTRIES 32 104 105 /* The PnP BIOS entries in the GDT */ 106 #define GDT_ENTRY_PNPBIOS_CS32 (GDT_ENTRY_PNPBIOS_BASE + 0) 107 #define GDT_ENTRY_PNPBIOS_CS16 (GDT_ENTRY_PNPBIOS_BASE + 1) 108 #define GDT_ENTRY_PNPBIOS_DS (GDT_ENTRY_PNPBIOS_BASE + 2) 109 #define GDT_ENTRY_PNPBIOS_TS1 (GDT_ENTRY_PNPBIOS_BASE + 3) 110 #define GDT_ENTRY_PNPBIOS_TS2 (GDT_ENTRY_PNPBIOS_BASE + 4) 111 112 /* The PnP BIOS selectors */ 113 #define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */ 114 #define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */ 115 #define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */ 116 #define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */ 117 #define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */ 118 119 /* Bottom two bits of selector give the ring privilege level */ 120 #define SEGMENT_RPL_MASK 0x3 121 /* Bit 2 is table indicator (LDT/GDT) */ 122 #define SEGMENT_TI_MASK 0x4 123 124 /* User mode is privilege level 3 */ 125 #define USER_RPL 0x3 126 /* LDT segment has TI set, GDT has it cleared */ 127 #define SEGMENT_LDT 0x4 128 #define SEGMENT_GDT 0x0 129 130 /* 131 * Matching rules for certain types of segments. 132 */ 133 134 /* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ 135 #define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) 136 137 138 #else 139 #include <asm/cache.h> 140 141 #define GDT_ENTRY_KERNEL32_CS 1 142 #define GDT_ENTRY_KERNEL_CS 2 143 #define GDT_ENTRY_KERNEL_DS 3 144 145 #define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS * 8) 146 147 /* 148 * we cannot use the same code segment descriptor for user and kernel 149 * -- not even in the long flat mode, because of different DPL /kkeil 150 * The segment offset needs to contain a RPL. Grr. -AK 151 * GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets) 152 */ 153 #define GDT_ENTRY_DEFAULT_USER32_CS 4 154 #define GDT_ENTRY_DEFAULT_USER_DS 5 155 #define GDT_ENTRY_DEFAULT_USER_CS 6 156 #define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS * 8 + 3) 157 #define __USER32_DS __USER_DS 158 159 #define GDT_ENTRY_TSS 8 /* needs two entries */ 160 #define GDT_ENTRY_LDT 10 /* needs two entries */ 161 #define GDT_ENTRY_TLS_MIN 12 162 #define GDT_ENTRY_TLS_MAX 14 163 164 #define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */ 165 #define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3) 166 167 /* TLS indexes for 64bit - hardcoded in arch_prctl */ 168 #define FS_TLS 0 169 #define GS_TLS 1 170 171 #define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3) 172 #define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3) 173 174 #define GDT_ENTRIES 16 175 176 #endif 177 178 #define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8) 179 #define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8) 180 #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS* 8 + 3) 181 #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS* 8 + 3) 182 #ifndef CONFIG_PARAVIRT 183 #define get_kernel_rpl() 0 184 #endif 185 186 /* User mode is privilege level 3 */ 187 #define USER_RPL 0x3 188 /* LDT segment has TI set, GDT has it cleared */ 189 #define SEGMENT_LDT 0x4 190 #define SEGMENT_GDT 0x0 191 192 /* Bottom two bits of selector give the ring privilege level */ 193 #define SEGMENT_RPL_MASK 0x3 194 /* Bit 2 is table indicator (LDT/GDT) */ 195 #define SEGMENT_TI_MASK 0x4 196 197 #define IDT_ENTRIES 256 198 #define NUM_EXCEPTION_VECTORS 32 199 #define GDT_SIZE (GDT_ENTRIES * 8) 200 #define GDT_ENTRY_TLS_ENTRIES 3 201 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) 202 203 #ifdef __KERNEL__ 204 #ifndef __ASSEMBLY__ 205 extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10]; 206 #endif 207 #endif 208 209 #endif /* _ASM_X86_SEGMENT_H */ 210