2 * Copyright (c) 1989, 1990 William F. Jolitz
3 * Copyright (c) 1990 The Regents of the University of California.
6 * This code is derived from software contributed to Berkeley by
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10 * modification, are permitted provided that the following conditions
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21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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33 * from: @(#)segments.h 7.1 (Berkeley) 5/9/91
37 #ifndef _MACHINE_SEGMENTS_H_
38 #define _MACHINE_SEGMENTS_H_
41 * AMD64 Segmentation Data Structures and definitions
48 #define SEL_RPL_MASK 3 /* requester priv level */
49 #define ISPL(s) ((s)&3) /* what is the priority level of a selector */
50 #define SEL_KPL 0 /* kernel priority level */
51 #define SEL_UPL 3 /* user priority level */
52 #define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */
53 #define SEL_LDT 4 /* local descriptor table */
54 #define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */
55 #define LSEL(s,r) (((s)<<3) | SEL_LDT | r) /* a local selector */
56 #define GSEL(s,r) (((s)<<3) | r) /* a global selector */
59 * User segment descriptors (%cs, %ds etc for compatability apps. 64 bit wide)
60 * For long-mode apps, %cs only has the conforming bit in sd_type, the sd_dpl,
61 * sd_p, sd_l and sd_def32 which must be zero). %ds only has sd_p.
63 struct user_segment_descriptor {
64 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
65 u_int64_t sd_lobase:24; /* segment base address (lsb) */
66 u_int64_t sd_type:5; /* segment type */
67 u_int64_t sd_dpl:2; /* segment descriptor priority level */
68 u_int64_t sd_p:1; /* segment descriptor present */
69 u_int64_t sd_hilimit:4; /* segment extent (msb) */
70 u_int64_t sd_xx:1; /* unused */
71 u_int64_t sd_long:1; /* long mode (cs only) */
72 u_int64_t sd_def32:1; /* default 32 vs 16 bit size */
73 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
74 u_int64_t sd_hibase:8; /* segment base address (msb) */
78 * System segment descriptors (128 bit wide)
80 struct system_segment_descriptor {
81 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
82 u_int64_t sd_lobase:24; /* segment base address (lsb) */
83 u_int64_t sd_type:5; /* segment type */
84 u_int64_t sd_dpl:2; /* segment descriptor priority level */
85 u_int64_t sd_p:1; /* segment descriptor present */
86 u_int64_t sd_hilimit:4; /* segment extent (msb) */
87 u_int64_t sd_xx0:3; /* unused */
88 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
89 u_int64_t sd_hibase:40 __packed;/* segment base address (msb) */
91 u_int64_t sd_mbz:5; /* MUST be zero */
96 * Gate descriptors (e.g. indirect descriptors, trap, interrupt etc. 128 bit)
97 * Only interrupt and trap gates have gd_ist.
99 struct gate_descriptor {
100 u_int64_t gd_looffset:16; /* gate offset (lsb) */
101 u_int64_t gd_selector:16; /* gate segment selector */
102 u_int64_t gd_ist:3; /* IST table index */
103 u_int64_t gd_xx:5; /* unused */
104 u_int64_t gd_type:5; /* segment type */
105 u_int64_t gd_dpl:2; /* segment descriptor priority level */
106 u_int64_t gd_p:1; /* segment descriptor present */
107 u_int64_t gd_hioffset:48 __packed; /* gate offset (msb) */
115 struct user_segment_descriptor sd;
116 struct gate_descriptor gd;
119 /* system segments and gate types */
120 #define SDT_SYSNULL 0 /* system null */
121 #define SDT_SYS286TSS 1 /* system 286 TSS available */
122 #define SDT_SYSLDT 2 /* system 64 bit local descriptor table */
123 #define SDT_SYS286BSY 3 /* system 286 TSS busy */
124 #define SDT_SYS286CGT 4 /* system 286 call gate */
125 #define SDT_SYSTASKGT 5 /* system task gate */
126 #define SDT_SYS286IGT 6 /* system 286 interrupt gate */
127 #define SDT_SYS286TGT 7 /* system 286 trap gate */
128 #define SDT_SYSNULL2 8 /* system null again */
129 #define SDT_SYSTSS 9 /* system available 64 bit TSS */
130 #define SDT_SYSNULL3 10 /* system null again */
131 #define SDT_SYSBSY 11 /* system busy 64 bit TSS */
132 #define SDT_SYSCGT 12 /* system 64 bit call gate */
133 #define SDT_SYSNULL4 13 /* system null again */
134 #define SDT_SYSIGT 14 /* system 64 bit interrupt gate */
135 #define SDT_SYSTGT 15 /* system 64 bit trap gate */
137 /* memory segment types */
138 #define SDT_MEMRO 16 /* memory read only */
139 #define SDT_MEMROA 17 /* memory read only accessed */
140 #define SDT_MEMRW 18 /* memory read write */
141 #define SDT_MEMRWA 19 /* memory read write accessed */
142 #define SDT_MEMROD 20 /* memory read only expand dwn limit */
143 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
144 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */
145 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */
146 #define SDT_MEME 24 /* memory execute only */
147 #define SDT_MEMEA 25 /* memory execute only accessed */
148 #define SDT_MEMER 26 /* memory execute read */
149 #define SDT_MEMERA 27 /* memory execute read accessed */
150 #define SDT_MEMEC 28 /* memory execute only conforming */
151 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */
152 #define SDT_MEMERC 30 /* memory execute read conforming */
153 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */
156 * Software definitions are in this convenient format,
157 * which are translated into inconvenient segment descriptors
158 * when needed to be used by the 386 hardware
161 struct soft_segment_descriptor {
162 unsigned long ssd_base; /* segment base address */
163 unsigned long ssd_limit; /* segment extent */
164 unsigned long ssd_type:5; /* segment type */
165 unsigned long ssd_dpl:2; /* segment descriptor priority level */
166 unsigned long ssd_p:1; /* segment descriptor present */
167 unsigned long ssd_long:1; /* long mode (for %cs) */
168 unsigned long ssd_def32:1; /* default 32 vs 16 bit size */
169 unsigned long ssd_gran:1; /* limit granularity (byte/page units)*/
173 * region descriptors, used to load gdt/idt tables before segments yet exist.
175 struct region_descriptor {
176 unsigned long rd_limit:16; /* segment extent */
177 unsigned long rd_base:64 __packed; /* base address */
183 #define NIDT 256 /* 32 reserved, 16 h/w, 0 s/w, linux's 0x80 */
184 #define NRSVIDT 32 /* reserved entries for cpu exceptions */
187 * Entries in the Interrupt Descriptor Table (IDT)
189 #define IDT_DE 0 /* #DE: Divide Error */
190 #define IDT_DB 1 /* #DB: Debug */
191 #define IDT_NMI 2 /* Nonmaskable External Interrupt */
192 #define IDT_BP 3 /* #BP: Breakpoint */
193 #define IDT_OF 4 /* #OF: Overflow */
194 #define IDT_BR 5 /* #BR: Bound Range Exceeded */
195 #define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */
196 #define IDT_NM 7 /* #NM: No Math Coprocessor */
197 #define IDT_DF 8 /* #DF: Double Fault */
198 #define IDT_FPUGP 9 /* Coprocessor Segment Overrun */
199 #define IDT_TS 10 /* #TS: Invalid TSS */
200 #define IDT_NP 11 /* #NP: Segment Not Present */
201 #define IDT_SS 12 /* #SS: Stack Segment Fault */
202 #define IDT_GP 13 /* #GP: General Protection Fault */
203 #define IDT_PF 14 /* #PF: Page Fault */
204 #define IDT_MF 16 /* #MF: FPU Floating-Point Error */
205 #define IDT_AC 17 /* #AC: Alignment Check */
206 #define IDT_MC 18 /* #MC: Machine Check */
207 #define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
208 #define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
209 #define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
212 * Entries in the Global Descriptor Table (GDT)
214 #define GNULL_SEL 0 /* Null Descriptor */
215 #define GNULL2_SEL 1 /* Null Descriptor */
216 #define GUFS32_SEL 2 /* User 32 bit %fs Descriptor */
217 #define GUGS32_SEL 3 /* User 32 bit %gs Descriptor */
218 #define GCODE_SEL 4 /* Kernel Code Descriptor */
219 #define GDATA_SEL 5 /* Kernel Data Descriptor */
220 #define GUCODE32_SEL 6 /* User 32 bit code Descriptor */
221 #define GUDATA_SEL 7 /* User 32/64 bit Data Descriptor */
222 #define GUCODE_SEL 8 /* User 64 bit Code Descriptor */
223 #define GPROC0_SEL 9 /* TSS for entering kernel etc */
224 /* slot 10 is second half of GPROC0_SEL */
225 #define GUSERLDT_SEL 11 /* LDT */
226 /* slot 11 is second half of GUSERLDT_SEL */
230 extern struct user_segment_descriptor gdt[];
231 extern struct soft_segment_descriptor gdt_segs[];
232 extern struct gate_descriptor *idt;
233 extern struct region_descriptor r_gdt, r_idt;
235 void lgdt(struct region_descriptor *rdp);
236 void sdtossd(struct user_segment_descriptor *sdp,
237 struct soft_segment_descriptor *ssdp);
238 void ssdtosd(struct soft_segment_descriptor *ssdp,
239 struct user_segment_descriptor *sdp);
240 void ssdtosyssd(struct soft_segment_descriptor *ssdp,
241 struct system_segment_descriptor *sdp);
242 void update_gdt_gsbase(struct thread *td, uint32_t base);
243 void update_gdt_fsbase(struct thread *td, uint32_t base);
247 #endif /* !_MACHINE_SEGMENTS_H_ */