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 /*
12 * Low-level interface mapping flags/field names to bits
13 */
14
15 /* Flags for _DESC_S (non-system) descriptors */
16 #define _DESC_ACCESSED 0x0001
17 #define _DESC_DATA_WRITABLE 0x0002
18 #define _DESC_CODE_READABLE 0x0002
19 #define _DESC_DATA_EXPAND_DOWN 0x0004
20 #define _DESC_CODE_CONFORMING 0x0004
21 #define _DESC_CODE_EXECUTABLE 0x0008
22
23 /* Common flags */
24 #define _DESC_S 0x0010
25 #define _DESC_DPL(dpl) ((dpl) << 5)
26 #define _DESC_PRESENT 0x0080
27
28 #define _DESC_LONG_CODE 0x2000
29 #define _DESC_DB 0x4000
30 #define _DESC_GRANULARITY_4K 0x8000
31
32 /* System descriptors have a numeric "type" field instead of flags */
33 #define _DESC_SYSTEM(code) (code)
34
35 /*
36 * High-level interface mapping intended usage to low-level combinations
37 * of flags
38 */
39
40 #define _DESC_DATA (_DESC_S | _DESC_PRESENT | _DESC_ACCESSED | \
41 _DESC_DATA_WRITABLE)
42 #define _DESC_CODE (_DESC_S | _DESC_PRESENT | _DESC_ACCESSED | \
43 _DESC_CODE_READABLE | _DESC_CODE_EXECUTABLE)
44
45 #define DESC_DATA16 (_DESC_DATA)
46 #define DESC_CODE16 (_DESC_CODE)
47
48 #define DESC_DATA32 (_DESC_DATA | _DESC_GRANULARITY_4K | _DESC_DB)
49 #define DESC_DATA32_BIOS (_DESC_DATA | _DESC_DB)
50
51 #define DESC_CODE32 (_DESC_CODE | _DESC_GRANULARITY_4K | _DESC_DB)
52 #define DESC_CODE32_BIOS (_DESC_CODE | _DESC_DB)
53
54 #define DESC_TSS32 (_DESC_SYSTEM(9) | _DESC_PRESENT)
55
56 #define DESC_DATA64 (_DESC_DATA | _DESC_GRANULARITY_4K | _DESC_DB)
57 #define DESC_CODE64 (_DESC_CODE | _DESC_GRANULARITY_4K | _DESC_LONG_CODE)
58
59 #define DESC_USER (_DESC_DPL(3))
60
61 #ifndef __ASSEMBLY__
62
63 #include <linux/types.h>
64
65 /* 8 byte segment descriptor */
66 struct desc_struct {
67 u16 limit0;
68 u16 base0;
69 u16 base1: 8, type: 4, s: 1, dpl: 2, p: 1;
70 u16 limit1: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
71 } __attribute__((packed));
72
73 #define GDT_ENTRY_INIT(flags, base, limit) \
74 { \
75 .limit0 = ((limit) >> 0) & 0xFFFF, \
76 .limit1 = ((limit) >> 16) & 0x000F, \
77 .base0 = ((base) >> 0) & 0xFFFF, \
78 .base1 = ((base) >> 16) & 0x00FF, \
79 .base2 = ((base) >> 24) & 0x00FF, \
80 .type = ((flags) >> 0) & 0x000F, \
81 .s = ((flags) >> 4) & 0x0001, \
82 .dpl = ((flags) >> 5) & 0x0003, \
83 .p = ((flags) >> 7) & 0x0001, \
84 .avl = ((flags) >> 12) & 0x0001, \
85 .l = ((flags) >> 13) & 0x0001, \
86 .d = ((flags) >> 14) & 0x0001, \
87 .g = ((flags) >> 15) & 0x0001, \
88 }
89
90 enum {
91 GATE_INTERRUPT = 0xE,
92 GATE_TRAP = 0xF,
93 GATE_CALL = 0xC,
94 GATE_TASK = 0x5,
95 };
96
97 enum {
98 DESC_TSS = 0x9,
99 DESC_LDT = 0x2,
100 DESCTYPE_S = 0x10, /* !system */
101 };
102
103 /* LDT or TSS descriptor in the GDT. */
104 struct ldttss_desc {
105 u16 limit0;
106 u16 base0;
107
108 u16 base1 : 8, type : 5, dpl : 2, p : 1;
109 u16 limit1 : 4, zero0 : 3, g : 1, base2 : 8;
110 #ifdef CONFIG_X86_64
111 u32 base3;
112 u32 zero1;
113 #endif
114 } __attribute__((packed));
115
116 typedef struct ldttss_desc ldt_desc;
117 typedef struct ldttss_desc tss_desc;
118
119 struct idt_bits {
120 u16 ist : 3,
121 zero : 5,
122 type : 5,
123 dpl : 2,
124 p : 1;
125 } __attribute__((packed));
126
127 struct idt_data {
128 unsigned int vector;
129 unsigned int segment;
130 struct idt_bits bits;
131 const void *addr;
132 };
133
134 struct gate_struct {
135 u16 offset_low;
136 u16 segment;
137 struct idt_bits bits;
138 u16 offset_middle;
139 #ifdef CONFIG_X86_64
140 u32 offset_high;
141 u32 reserved;
142 #endif
143 } __attribute__((packed));
144
145 typedef struct gate_struct gate_desc;
146
147 #ifndef _SETUP
148 static inline unsigned long gate_offset(const gate_desc *g)
149 {
150 #ifdef CONFIG_X86_64
151 return g->offset_low | ((unsigned long)g->offset_middle << 16) |
152 ((unsigned long) g->offset_high << 32);
153 #else
154 return g->offset_low | ((unsigned long)g->offset_middle << 16);
155 #endif
156 }
157
158 static inline unsigned long gate_segment(const gate_desc *g)
159 {
160 return g->segment;
161 }
162 #endif
163
164 struct desc_ptr {
165 unsigned short size;
166 unsigned long address;
167 } __attribute__((packed)) ;
168
169 #endif /* !__ASSEMBLY__ */
170
171 /* Boot IDT definitions */
172 #define BOOT_IDT_ENTRIES 32
173
174 /* Access rights as returned by LAR */
175 #define AR_TYPE_RODATA (0 * (1 << 9))
176 #define AR_TYPE_RWDATA (1 * (1 << 9))
177 #define AR_TYPE_RODATA_EXPDOWN (2 * (1 << 9))
178 #define AR_TYPE_RWDATA_EXPDOWN (3 * (1 << 9))
179 #define AR_TYPE_XOCODE (4 * (1 << 9))
180 #define AR_TYPE_XRCODE (5 * (1 << 9))
181 #define AR_TYPE_XOCODE_CONF (6 * (1 << 9))
182 #define AR_TYPE_XRCODE_CONF (7 * (1 << 9))
183 #define AR_TYPE_MASK (7 * (1 << 9))
184
185 #define AR_DPL0 (0 * (1 << 13))
186 #define AR_DPL3 (3 * (1 << 13))
187 #define AR_DPL_MASK (3 * (1 << 13))
188
189 #define AR_A (1 << 8) /* "Accessed" */
190 #define AR_S (1 << 12) /* If clear, "System" segment */
191 #define AR_P (1 << 15) /* "Present" */
192 #define AR_AVL (1 << 20) /* "AVaiLable" (no HW effect) */
193 #define AR_L (1 << 21) /* "Long mode" for code segments */
194 #define AR_DB (1 << 22) /* D/B, effect depends on type */
195 #define AR_G (1 << 23) /* "Granularity" (limit in pages) */
196
197 #endif /* _ASM_X86_DESC_DEFS_H */
198
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