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1da177e4 LT |
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 | |
7c3576d2 | 42 | * 27 - per-cpu [ offset to per-cpu data area ] |
1da177e4 LT |
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 | ||
7c3576d2 | 77 | #define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE + 15) |
c5413fbe | 78 | #ifdef CONFIG_SMP |
7c3576d2 | 79 | #define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8) |
c5413fbe JF |
80 | #else |
81 | #define __KERNEL_PERCPU 0 | |
82 | #endif | |
9ca36101 | 83 | |
1da177e4 LT |
84 | #define GDT_ENTRY_DOUBLEFAULT_TSS 31 |
85 | ||
86 | /* | |
87 | * The GDT has 32 entries | |
88 | */ | |
89 | #define GDT_ENTRIES 32 | |
1da177e4 LT |
90 | #define GDT_SIZE (GDT_ENTRIES * 8) |
91 | ||
92 | /* Simple and small GDT entries for booting only */ | |
93 | ||
94 | #define GDT_ENTRY_BOOT_CS 2 | |
95 | #define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8) | |
96 | ||
97 | #define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1) | |
98 | #define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) | |
99 | ||
5702d0f7 ZA |
100 | /* The PnP BIOS entries in the GDT */ |
101 | #define GDT_ENTRY_PNPBIOS_CS32 (GDT_ENTRY_PNPBIOS_BASE + 0) | |
102 | #define GDT_ENTRY_PNPBIOS_CS16 (GDT_ENTRY_PNPBIOS_BASE + 1) | |
103 | #define GDT_ENTRY_PNPBIOS_DS (GDT_ENTRY_PNPBIOS_BASE + 2) | |
104 | #define GDT_ENTRY_PNPBIOS_TS1 (GDT_ENTRY_PNPBIOS_BASE + 3) | |
105 | #define GDT_ENTRY_PNPBIOS_TS2 (GDT_ENTRY_PNPBIOS_BASE + 4) | |
106 | ||
107 | /* The PnP BIOS selectors */ | |
108 | #define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */ | |
109 | #define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */ | |
110 | #define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */ | |
111 | #define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */ | |
112 | #define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */ | |
113 | ||
1da177e4 LT |
114 | /* |
115 | * The interrupt descriptor table has room for 256 idt's, | |
116 | * the global descriptor table is dependent on the number | |
117 | * of tasks we can have.. | |
118 | */ | |
119 | #define IDT_ENTRIES 256 | |
120 | ||
78be3706 RR |
121 | /* Bottom two bits of selector give the ring privilege level */ |
122 | #define SEGMENT_RPL_MASK 0x3 | |
123 | /* Bit 2 is table indicator (LDT/GDT) */ | |
124 | #define SEGMENT_TI_MASK 0x4 | |
125 | ||
126 | /* User mode is privilege level 3 */ | |
127 | #define USER_RPL 0x3 | |
128 | /* LDT segment has TI set, GDT has it cleared */ | |
129 | #define SEGMENT_LDT 0x4 | |
130 | #define SEGMENT_GDT 0x0 | |
131 | ||
d3561b7f | 132 | #ifndef CONFIG_PARAVIRT |
78be3706 | 133 | #define get_kernel_rpl() 0 |
1da177e4 | 134 | #endif |
7b355202 ZA |
135 | /* |
136 | * Matching rules for certain types of segments. | |
137 | */ | |
138 | ||
139 | /* Matches only __KERNEL_CS, ignoring PnP / USER / APM segments */ | |
140 | #define SEGMENT_IS_KERNEL_CODE(x) (((x) & 0xfc) == GDT_ENTRY_KERNEL_CS * 8) | |
141 | ||
142 | /* Matches __KERNEL_CS and __USER_CS (they must be 2 entries apart) */ | |
143 | #define SEGMENT_IS_FLAT_CODE(x) (((x) & 0xec) == GDT_ENTRY_KERNEL_CS * 8) | |
144 | ||
145 | /* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ | |
146 | #define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) | |
147 | ||
d3561b7f | 148 | #endif |