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 __ASSEMBLER__
62
63#include <linux/types.h>
64
65/* 8 byte segment descriptor */
66struct 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
90enum {
91 GATE_INTERRUPT = 0xE,
92 GATE_TRAP = 0xF,
93 GATE_CALL = 0xC,
94 GATE_TASK = 0x5,
95};
96
97enum {
98 DESC_TSS = 0x9,
99 DESC_LDT = 0x2,
100 DESCTYPE_S = 0x10, /* !system */
101};
102
103/* LDT or TSS descriptor in the GDT. */
104struct 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
116typedef struct ldttss_desc ldt_desc;
117typedef struct ldttss_desc tss_desc;
118
119struct idt_bits {
120 u16 ist : 3,
121 zero : 5,
122 type : 5,
123 dpl : 2,
124 p : 1;
125} __attribute__((packed));
126
127struct idt_data {
128 unsigned int vector;
129 unsigned int segment;
130 struct idt_bits bits;
131 const void *addr;
132};
133
134struct 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
145typedef struct gate_struct gate_desc;
146
147#ifndef _SETUP
148static 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
158static inline unsigned long gate_segment(const gate_desc *g)
159{
160 return g->segment;
161}
162#endif
163
164struct desc_ptr {
165 unsigned short size;
166 unsigned long address;
167} __attribute__((packed)) ;
168
169#endif /* !__ASSEMBLER__ */
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

source code of linux/arch/x86/include/asm/desc_defs.h