| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | #ifndef _ASM_SEGMENT_H |
| 2 | #define _ASM_SEGMENT_H |
| 3 | |
| 4 | /* |
| 5 | * The layout of the per-CPU GDT under Linux: |
| 6 | * |
| 7 | * 0 - null |
| 8 | * 1 - reserved |
| 9 | * 2 - reserved |
| 10 | * 3 - reserved |
| 11 | * |
| 12 | * 4 - unused <==== new cacheline |
| 13 | * 5 - unused |
| 14 | * |
| 15 | * ------- start of TLS (Thread-Local Storage) segments: |
| 16 | * |
| 17 | * 6 - TLS segment #1 [ glibc's TLS segment ] |
| 18 | * 7 - TLS segment #2 [ Wine's %fs Win32 segment ] |
| 19 | * 8 - TLS segment #3 |
| 20 | * 9 - reserved |
| 21 | * 10 - reserved |
| 22 | * 11 - reserved |
| 23 | * |
| 24 | * ------- start of kernel segments: |
| 25 | * |
| 26 | * 12 - kernel code segment <==== new cacheline |
| 27 | * 13 - kernel data segment |
| 28 | * 14 - default user CS |
| 29 | * 15 - default user DS |
| 30 | * 16 - TSS |
| 31 | * 17 - LDT |
| 32 | * 18 - PNPBIOS support (16->32 gate) |
| 33 | * 19 - PNPBIOS support |
| 34 | * 20 - PNPBIOS support |
| 35 | * 21 - PNPBIOS support |
| 36 | * 22 - PNPBIOS support |
| 37 | * 23 - APM BIOS support |
| 38 | * 24 - APM BIOS support |
| 39 | * 25 - APM BIOS support |
| 40 | * |
| 41 | * 26 - ESPFIX small SS |
| 42 | * 27 - unused |
| 43 | * 28 - unused |
| 44 | * 29 - unused |
| 45 | * 30 - unused |
| 46 | * 31 - TSS for double fault handler |
| 47 | */ |
| 48 | #define GDT_ENTRY_TLS_ENTRIES 3 |
| 49 | #define GDT_ENTRY_TLS_MIN 6 |
| 50 | #define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1) |
| 51 | |
| 52 | #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) |
| 53 | |
| 54 | #define GDT_ENTRY_DEFAULT_USER_CS 14 |
| 55 | #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS * 8 + 3) |
| 56 | |
| 57 | #define GDT_ENTRY_DEFAULT_USER_DS 15 |
| 58 | #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS * 8 + 3) |
| 59 | |
| 60 | #define GDT_ENTRY_KERNEL_BASE 12 |
| 61 | |
| 62 | #define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE + 0) |
| 63 | #define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8) |
| 64 | |
| 65 | #define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE + 1) |
| 66 | #define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8) |
| 67 | |
| 68 | #define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE + 4) |
| 69 | #define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE + 5) |
| 70 | |
| 71 | #define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 6) |
| 72 | #define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 11) |
| 73 | |
| 74 | #define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14) |
| 75 | #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8) |
| 76 | |
| 77 | #define GDT_ENTRY_DOUBLEFAULT_TSS 31 |
| 78 | |
| 79 | /* |
| 80 | * The GDT has 32 entries |
| 81 | */ |
| 82 | #define GDT_ENTRIES 32 |
| 83 | |
| 84 | #define GDT_SIZE (GDT_ENTRIES * 8) |
| 85 | |
| 86 | /* Simple and small GDT entries for booting only */ |
| 87 | |
| 88 | #define GDT_ENTRY_BOOT_CS 2 |
| 89 | #define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8) |
| 90 | |
| 91 | #define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1) |
| 92 | #define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) |
| 93 | |
| 94 | /* |
| 95 | * The interrupt descriptor table has room for 256 idt's, |
| 96 | * the global descriptor table is dependent on the number |
| 97 | * of tasks we can have.. |
| 98 | */ |
| 99 | #define IDT_ENTRIES 256 |
| 100 | |
| 101 | #endif |