include/asm-x86/segment.h

   1 #ifndef _ASM_X86_SEGMENT_H_
   2 #define _ASM_X86_SEGMENT_H_
   3
   4 /* Simple and small GDT entries for booting only */
   5
   6 #define GDT_ENTRY_BOOT_CS       2
   7 #define __BOOT_CS               (GDT_ENTRY_BOOT_CS * 8)
   8
   9 #define GDT_ENTRY_BOOT_DS       (GDT_ENTRY_BOOT_CS + 1)
  10 #define __BOOT_DS               (GDT_ENTRY_BOOT_DS * 8)
  11
  12 #define GDT_ENTRY_BOOT_TSS      (GDT_ENTRY_BOOT_CS + 2)
  13 #define __BOOT_TSS              (GDT_ENTRY_BOOT_TSS * 8)
  14
  15 #ifdef CONFIG_X86_32
  16 /*
  17  * The layout of the per-CPU GDT under Linux:
  18  *
  19  *   0 - null
  20  *   1 - reserved
  21  *   2 - reserved
  22  *   3 - reserved
  23  *
  24  *   4 - unused                 <==== new cacheline
  25  *   5 - unused
  26  *
  27  *  ------- start of TLS (Thread-Local Storage) segments:
  28  *
  29  *   6 - TLS segment #1                 [ glibc's TLS segment ]
  30  *   7 - TLS segment #2                 [ Wine's %fs Win32 segment ]
  31  *   8 - TLS segment #3
  32  *   9 - reserved
  33  *  10 - reserved
  34  *  11 - reserved
  35  *
  36  *  ------- start of kernel segments:
  37  *
  38  *  12 - kernel code segment            <==== new cacheline
  39  *  13 - kernel data segment
  40  *  14 - default user CS
  41  *  15 - default user DS
  42  *  16 - TSS
  43  *  17 - LDT
  44  *  18 - PNPBIOS support (16->32 gate)
  45  *  19 - PNPBIOS support
  46  *  20 - PNPBIOS support
  47  *  21 - PNPBIOS support
  48  *  22 - PNPBIOS support
  49  *  23 - APM BIOS support
  50  *  24 - APM BIOS support
  51  *  25 - APM BIOS support
  52  *
  53  *  26 - ESPFIX small SS
  54  *  27 - per-cpu                        [ offset to per-cpu data area ]
  55  *  28 - unused
  56  *  29 - unused
  57  *  30 - unused
  58  *  31 - TSS for double fault handler
  59  */
  60 #define GDT_ENTRY_TLS_MIN       6
  61 #define GDT_ENTRY_TLS_MAX       (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
  62
  63 #define GDT_ENTRY_DEFAULT_USER_CS       14
  64
  65 #define GDT_ENTRY_DEFAULT_USER_DS       15
  66
  67 #define GDT_ENTRY_KERNEL_BASE   12
  68
  69 #define GDT_ENTRY_KERNEL_CS             (GDT_ENTRY_KERNEL_BASE + 0)
  70
  71 #define GDT_ENTRY_KERNEL_DS             (GDT_ENTRY_KERNEL_BASE + 1)
  72
  73 #define GDT_ENTRY_TSS                   (GDT_ENTRY_KERNEL_BASE + 4)
  74 #define GDT_ENTRY_LDT                   (GDT_ENTRY_KERNEL_BASE + 5)
  75
  76 #define GDT_ENTRY_PNPBIOS_BASE          (GDT_ENTRY_KERNEL_BASE + 6)
  77 #define GDT_ENTRY_APMBIOS_BASE          (GDT_ENTRY_KERNEL_BASE + 11)
  78
  79 #define GDT_ENTRY_ESPFIX_SS             (GDT_ENTRY_KERNEL_BASE + 14)
  80 #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8)
  81
  82 #define GDT_ENTRY_PERCPU                        (GDT_ENTRY_KERNEL_BASE + 15)
  83 #ifdef CONFIG_SMP
  84 #define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8)
  85 #else
  86 #define __KERNEL_PERCPU 0
  87 #endif
  88
  89 #define GDT_ENTRY_DOUBLEFAULT_TSS       31
  90
  91 /*
  92  * The GDT has 32 entries
  93  */
  94 #define GDT_ENTRIES 32
  95
  96 /* The PnP BIOS entries in the GDT */
  97 #define GDT_ENTRY_PNPBIOS_CS32          (GDT_ENTRY_PNPBIOS_BASE + 0)
  98 #define GDT_ENTRY_PNPBIOS_CS16          (GDT_ENTRY_PNPBIOS_BASE + 1)
  99 #define GDT_ENTRY_PNPBIOS_DS            (GDT_ENTRY_PNPBIOS_BASE + 2)
 100 #define GDT_ENTRY_PNPBIOS_TS1           (GDT_ENTRY_PNPBIOS_BASE + 3)
 101 #define GDT_ENTRY_PNPBIOS_TS2           (GDT_ENTRY_PNPBIOS_BASE + 4)
 102
 103 /* The PnP BIOS selectors */
 104 #define PNP_CS32   (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */
 105 #define PNP_CS16   (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */
 106 #define PNP_DS     (GDT_ENTRY_PNPBIOS_DS * 8)   /* data segment for BIOS */
 107 #define PNP_TS1    (GDT_ENTRY_PNPBIOS_TS1 * 8)  /* transfer data segment */
 108 #define PNP_TS2    (GDT_ENTRY_PNPBIOS_TS2 * 8)  /* another data segment */
 109
 110 /* Bottom two bits of selector give the ring privilege level */
 111 #define SEGMENT_RPL_MASK        0x3
 112 /* Bit 2 is table indicator (LDT/GDT) */
 113 #define SEGMENT_TI_MASK         0x4
 114
 115 /* User mode is privilege level 3 */
 116 #define USER_RPL                0x3
 117 /* LDT segment has TI set, GDT has it cleared */
 118 #define SEGMENT_LDT             0x4
 119 #define SEGMENT_GDT             0x0
 120
 121 /*
 122  * Matching rules for certain types of segments.
 123  */
 124
 125 /* Matches only __KERNEL_CS, ignoring PnP / USER / APM segments */
 126 #define SEGMENT_IS_KERNEL_CODE(x) (((x) & 0xfc) == GDT_ENTRY_KERNEL_CS * 8)
 127
 128 /* Matches __KERNEL_CS and __USER_CS (they must be 2 entries apart) */
 129 #define SEGMENT_IS_FLAT_CODE(x)  (((x) & 0xec) == GDT_ENTRY_KERNEL_CS * 8)
 130
 131 /* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */
 132 #define SEGMENT_IS_PNP_CODE(x)   (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8)
 133
 134
 135 #else
 136 #include <asm/cache.h>
 137
 138 #define GDT_ENTRY_KERNEL32_CS 1
 139 #define GDT_ENTRY_KERNEL_CS 2
 140 #define GDT_ENTRY_KERNEL_DS 3
 141
 142 #define __KERNEL32_CS   (GDT_ENTRY_KERNEL32_CS * 8)
 143
 144 /*
 145  * we cannot use the same code segment descriptor for user and kernel
 146  * -- not even in the long flat mode, because of different DPL /kkeil
 147  * The segment offset needs to contain a RPL. Grr. -AK
 148  * GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)
 149  */
 150 #define GDT_ENTRY_DEFAULT_USER32_CS 4
 151 #define GDT_ENTRY_DEFAULT_USER_DS 5
 152 #define GDT_ENTRY_DEFAULT_USER_CS 6
 153 #define __USER32_CS   (GDT_ENTRY_DEFAULT_USER32_CS * 8 + 3)
 154 #define __USER32_DS     __USER_DS
 155
 156 #define GDT_ENTRY_TSS 8 /* needs two entries */
 157 #define GDT_ENTRY_LDT 10 /* needs two entries */
 158 #define GDT_ENTRY_TLS_MIN 12
 159 #define GDT_ENTRY_TLS_MAX 14
 160
 161 #define GDT_ENTRY_PER_CPU 15    /* Abused to load per CPU data from limit */
 162 #define __PER_CPU_SEG   (GDT_ENTRY_PER_CPU * 8 + 3)
 163
 164 /* TLS indexes for 64bit - hardcoded in arch_prctl */
 165 #define FS_TLS 0
 166 #define GS_TLS 1
 167
 168 #define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
 169 #define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)
 170
 171 #define GDT_ENTRIES 16
 172
 173 #endif
 174
 175 #define __KERNEL_CS     (GDT_ENTRY_KERNEL_CS * 8)
 176 #define __KERNEL_DS     (GDT_ENTRY_KERNEL_DS * 8)
 177 #define __USER_DS     (GDT_ENTRY_DEFAULT_USER_DS* 8 + 3)
 178 #define __USER_CS     (GDT_ENTRY_DEFAULT_USER_CS* 8 + 3)
 179 #ifndef CONFIG_PARAVIRT
 180 #define get_kernel_rpl()  0
 181 #endif
 182
 183 /* User mode is privilege level 3 */
 184 #define USER_RPL                0x3
 185 /* LDT segment has TI set, GDT has it cleared */
 186 #define SEGMENT_LDT             0x4
 187 #define SEGMENT_GDT             0x0
 188
 189 /* Bottom two bits of selector give the ring privilege level */
 190 #define SEGMENT_RPL_MASK        0x3
 191 /* Bit 2 is table indicator (LDT/GDT) */
 192 #define SEGMENT_TI_MASK         0x4
 193
 194 #define IDT_ENTRIES 256
 195 #define NUM_EXCEPTION_VECTORS 32
 196 #define GDT_SIZE (GDT_ENTRIES * 8)
 197 #define GDT_ENTRY_TLS_ENTRIES 3
 198 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
 199
 200 #ifdef __KERNEL__
 201 #ifndef __ASSEMBLY__
 202 extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10];
 203 #endif
 204 #endif
 205
 206 #endif