1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Written 2000 by Andi Kleen */
3 #ifndef _ASM_X86_DESC_DEFS_H
4 #define _ASM_X86_DESC_DEFS_H
5
6 /*
7 * Segment descriptor structure definitions, usable from both x86_64 and i386
8 * archs.
9 */
10
11 #ifndef __ASSEMBLY__
12
13 #include <linux/types.h>
14
15 /* 8 byte segment descriptor */
16 struct desc_struct {
17 u16 limit0;
18 u16 base0;
19 u16 base1: 8, type: 4, s: 1, dpl: 2, p: 1;
20 u16 limit1: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
21 } __attribute__((packed));
22
23 #define GDT_ENTRY_INIT(flags, base, limit) \
24 { \
25 .limit0 = (u16) (limit), \
26 .limit1 = ((limit) >> 16) & 0x0F, \
27 .base0 = (u16) (base), \
28 .base1 = ((base) >> 16) & 0xFF, \
29 .base2 = ((base) >> 24) & 0xFF, \
30 .type = (flags & 0x0f), \
31 .s = (flags >> 4) & 0x01, \
32 .dpl = (flags >> 5) & 0x03, \
33 .p = (flags >> 7) & 0x01, \
34 .avl = (flags >> 12) & 0x01, \
35 .l = (flags >> 13) & 0x01, \
36 .d = (flags >> 14) & 0x01, \
37 .g = (flags >> 15) & 0x01, \
38 }
39
40 enum {
41 GATE_INTERRUPT = 0xE,
42 GATE_TRAP = 0xF,
43 GATE_CALL = 0xC,
44 GATE_TASK = 0x5,
45 };
46
47 enum {
48 DESC_TSS = 0x9,
49 DESC_LDT = 0x2,
50 DESCTYPE_S = 0x10, /* !system */
51 };
52
53 /* LDT or TSS descriptor in the GDT. */
54 struct ldttss_desc {
55 u16 limit0;
56 u16 base0;
57
58 u16 base1 : 8, type : 5, dpl : 2, p : 1;
59 u16 limit1 : 4, zero0 : 3, g : 1, base2 : 8;
60 #ifdef CONFIG_X86_64
61 u32 base3;
62 u32 zero1;
63 #endif
64 } __attribute__((packed));
65
66 typedef struct ldttss_desc ldt_desc;
67 typedef struct ldttss_desc tss_desc;
68
69 struct idt_bits {
70 u16 ist : 3,
71 zero : 5,
72 type : 5,
73 dpl : 2,
74 p : 1;
75 } __attribute__((packed));
76
77 struct gate_struct {
78 u16 offset_low;
79 u16 segment;
80 struct idt_bits bits;
81 u16 offset_middle;
82 #ifdef CONFIG_X86_64
83 u32 offset_high;
84 u32 reserved;
85 #endif
86 } __attribute__((packed));
87
88 typedef struct gate_struct gate_desc;
89
gate_offset(const gate_desc * g)90 static inline unsigned long gate_offset(const gate_desc *g)
91 {
92 #ifdef CONFIG_X86_64
93 return g->offset_low | ((unsigned long)g->offset_middle << 16) |
94 ((unsigned long) g->offset_high << 32);
95 #else
96 return g->offset_low | ((unsigned long)g->offset_middle << 16);
97 #endif
98 }
99
gate_segment(const gate_desc * g)100 static inline unsigned long gate_segment(const gate_desc *g)
101 {
102 return g->segment;
103 }
104
105 struct desc_ptr {
106 unsigned short size;
107 unsigned long address;
108 } __attribute__((packed)) ;
109
110 #endif /* !__ASSEMBLY__ */
111
112 /* Access rights as returned by LAR */
113 #define AR_TYPE_RODATA (0 * (1 << 9))
114 #define AR_TYPE_RWDATA (1 * (1 << 9))
115 #define AR_TYPE_RODATA_EXPDOWN (2 * (1 << 9))
116 #define AR_TYPE_RWDATA_EXPDOWN (3 * (1 << 9))
117 #define AR_TYPE_XOCODE (4 * (1 << 9))
118 #define AR_TYPE_XRCODE (5 * (1 << 9))
119 #define AR_TYPE_XOCODE_CONF (6 * (1 << 9))
120 #define AR_TYPE_XRCODE_CONF (7 * (1 << 9))
121 #define AR_TYPE_MASK (7 * (1 << 9))
122
123 #define AR_DPL0 (0 * (1 << 13))
124 #define AR_DPL3 (3 * (1 << 13))
125 #define AR_DPL_MASK (3 * (1 << 13))
126
127 #define AR_A (1 << 8) /* "Accessed" */
128 #define AR_S (1 << 12) /* If clear, "System" segment */
129 #define AR_P (1 << 15) /* "Present" */
130 #define AR_AVL (1 << 20) /* "AVaiLable" (no HW effect) */
131 #define AR_L (1 << 21) /* "Long mode" for code segments */
132 #define AR_DB (1 << 22) /* D/B, effect depends on type */
133 #define AR_G (1 << 23) /* "Granularity" (limit in pages) */
134
135 #endif /* _ASM_X86_DESC_DEFS_H */
136
