2 * Copyright (c) 1989, 1990 William F. Jolitz
3 * Copyright (c) 1990 The Regents of the University of California.
4 * Copyright (c) 2008 The DragonFly Project.
7 * This code is derived from software contributed to Berkeley by
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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14 * notice, this list of conditions and the following disclaimer.
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20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
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26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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38 * from: @(#)segments.h 7.1 (Berkeley) 5/9/91
39 * $FreeBSD: src/sys/i386/include/segments.h,v 1.24 1999/12/29 04:33:07 peter Exp $
40 * $DragonFly: src/sys/cpu/amd64/include/segments.h,v 1.3 2008/08/29 17:07:06 dillon Exp $
43 #ifndef _CPU_SEGMENTS_H_
44 #define _CPU_SEGMENTS_H_
47 * AMD64 Segmentation Data Structures and definitions
54 #define SEL_RPL_MASK 3 /* requester priv level */
55 #define ISPL(s) ((s)&3) /* what is the privilege level of a selector */
56 #define SEL_KPL 0 /* kernel privilege level */
57 #define SEL_UPL 3 /* user privilege level */
58 #define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */
59 #define SEL_LDT 4 /* local descriptor table */
60 #define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */
61 #define LSEL(s,r) (((s)<<3) | SEL_LDT | r) /* a local selector */
62 #define GSEL(s,r) (((s)<<3) | r) /* a global selector */
67 * User segment descriptors (%cs, %ds etc for compatability apps. 64 bit wide)
68 * For long-mode apps, %cs only has the conforming bit in sd_type, the sd_dpl,
69 * sd_p, sd_l and sd_def32 which must be zero). %ds only has sd_p.
71 struct user_segment_descriptor {
72 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
73 u_int64_t sd_lobase:24; /* segment base address (lsb) */
74 u_int64_t sd_type:5; /* segment type */
75 u_int64_t sd_dpl:2; /* segment descriptor priority level */
76 u_int64_t sd_p:1; /* segment descriptor present */
77 u_int64_t sd_hilimit:4; /* segment extent (msb) */
78 u_int64_t sd_xx:1; /* unused */
79 u_int64_t sd_long:1; /* long mode (cs only) */
80 u_int64_t sd_def32:1; /* default 32 vs 16 bit size */
81 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
82 u_int64_t sd_hibase:8; /* segment base address (msb) */
86 * System segment descriptors (128 bit wide)
88 struct system_segment_descriptor {
89 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
90 u_int64_t sd_lobase:24; /* segment base address (lsb) */
91 u_int64_t sd_type:5; /* segment type */
92 u_int64_t sd_dpl:2; /* segment descriptor priority level */
93 u_int64_t sd_p:1; /* segment descriptor present */
94 u_int64_t sd_hilimit:4; /* segment extent (msb) */
95 u_int64_t sd_xx0:3; /* unused */
96 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
97 u_int64_t sd_hibase:40 __packed;/* segment base address (msb) */
99 u_int64_t sd_mbz:5; /* MUST be zero */
104 * Gate descriptors (e.g. indirect descriptors, trap, interrupt etc. 128 bit)
105 * Only interrupt and trap gates have gd_ist.
107 struct gate_descriptor {
108 u_int64_t gd_looffset:16; /* gate offset (lsb) */
109 u_int64_t gd_selector:16; /* gate segment selector */
110 u_int64_t gd_ist:3; /* IST table index */
111 u_int64_t gd_xx:5; /* unused */
112 u_int64_t gd_type:5; /* segment type */
113 u_int64_t gd_dpl:2; /* segment descriptor priority level */
114 u_int64_t gd_p:1; /* segment descriptor present */
115 u_int64_t gd_hioffset:48 __packed; /* gate offset (msb) */
121 /* system segments and gate types */
122 #define SDT_SYSNULL 0 /* system null */
123 #define SDT_SYSLDT 2 /* system 64-bit local descriptor table */
124 #define SDT_SYSTSS 9 /* system available 64-bit TSS */
125 #define SDT_SYSBSY 11 /* system busy 64-bit TSS */
126 #define SDT_SYSCGT 12 /* system 64-bit call gate */
127 #define SDT_SYSIGT 14 /* system 64-bit interrupt gate */
128 #define SDT_SYSTGT 15 /* system 64-bit trap gate */
130 /* memory segment types */
131 #define SDT_MEMRO 16 /* memory read only */
132 #define SDT_MEMROA 17 /* memory read only accessed */
133 #define SDT_MEMRW 18 /* memory read write */
134 #define SDT_MEMRWA 19 /* memory read write accessed */
135 #define SDT_MEMROD 20 /* memory read only expand dwn limit */
136 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
137 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */
138 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */
139 #define SDT_MEME 24 /* memory execute only */
140 #define SDT_MEMEA 25 /* memory execute only accessed */
141 #define SDT_MEMER 26 /* memory execute read */
142 #define SDT_MEMERA 27 /* memory execute read accessed */
143 #define SDT_MEMEC 28 /* memory execute only conforming */
144 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */
145 #define SDT_MEMERC 30 /* memory execute read conforming */
146 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */
156 struct tls_info info[2];
159 /* is memory segment descriptor pointer ? */
160 #define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC)
162 /* is 286 gate descriptor pointer ? */
163 #define IS286GDP(s) (((s->d_type) >= SDT_SYS286CGT \
164 && (s->d_type) < SDT_SYS286TGT))
166 /* is 386 gate descriptor pointer ? */
167 #define IS386GDP(s) (((s->d_type) >= SDT_SYS386CGT \
168 && (s->d_type) < SDT_SYS386TGT))
170 /* is gate descriptor pointer ? */
171 #define ISGDP(s) (IS286GDP(s) || IS386GDP(s))
173 /* is segment descriptor pointer ? */
174 #define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s))
176 /* is system segment descriptor pointer ? */
177 #define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s))
180 * Software definitions are in this convenient format,
181 * which are translated into inconvenient segment descriptors
182 * when needed to be used by the 386 hardware
185 struct soft_segment_descriptor {
186 uint64_t ssd_base; /* segment base address */
187 uint64_t ssd_limit; /* segment extent */
188 uint64_t ssd_type:5; /* segment type */
189 uint64_t ssd_dpl:2; /* segment descriptor priority level */
190 uint64_t ssd_p:1; /* segment descriptor present */
191 uint64_t ssd_long:1; /* long mode (for %cs) */
192 uint64_t ssd_def32:1; /* default 32 vs 16 bit size */
193 uint64_t ssd_gran:1; /* limit granularity (byte/page units)*/
197 * region descriptors, used to load gdt/idt tables before segments yet exist.
199 struct region_descriptor {
200 uint64_t rd_limit:16; /* segment extent */
201 uint64_t rd_base:64 __packed; /* base address */
207 * Segment Protection Exception code bits
210 #define SEGEX_EXT 0x01 /* recursive or externally induced */
211 #define SEGEX_IDT 0x02 /* interrupt descriptor table */
212 #define SEGEX_TI 0x04 /* local descriptor table */
213 /* other bits are affected descriptor index */
214 #define SEGEX_IDX(s) ((s)>>3)&0x1fff)
217 * Size of the IDT table. Theoretically we only need to cover past 0x81
218 * (NIDT=130) if not running APIC_IO or SMP, but at this point we might
219 * as well just use all of them.
221 #define NIDT 256 /* we use them all */
223 * Entries in the Interrupt Descriptor Table (IDT)
225 #define IDT_DE 0 /* #DE: Divide Error */
226 #define IDT_DB 1 /* #DB: Debug */
227 #define IDT_NMI 2 /* Nonmaskable External Interrupt */
228 #define IDT_BP 3 /* #BP: Breakpoint */
229 #define IDT_OF 4 /* #OF: Overflow */
230 #define IDT_BR 5 /* #BR: Bound Range Exceeded */
231 #define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */
232 #define IDT_NM 7 /* #NM: No Math Coprocessor */
233 #define IDT_DF 8 /* #DF: Double Fault */
234 #define IDT_FPUGP 9 /* Coprocessor Segment Overrun */
235 #define IDT_TS 10 /* #TS: Invalid TSS */
236 #define IDT_NP 11 /* #NP: Segment Not Present */
237 #define IDT_SS 12 /* #SS: Stack Segment Fault */
238 #define IDT_GP 13 /* #GP: General Protection Fault */
239 #define IDT_PF 14 /* #PF: Page Fault */
240 #define IDT_MF 16 /* #MF: FPU Floating-Point Error */
241 #define IDT_AC 17 /* #AC: Alignment Check */
242 #define IDT_MC 18 /* #MC: Machine Check */
243 #define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
244 #define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
245 #define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
248 * Entries in the Global Descriptor Table (GDT)
250 #define GNULL_SEL 0 /* Null Descriptor */
251 #define GCODE_SEL 1 /* Kernel Code Descriptor */
252 #define GDATA_SEL 2 /* Kernel Data Descriptor */
253 #define GUCODE32_SEL 3 /* User 32 bit code Descriptor */
254 #define GUDATA_SEL 4 /* User 32/64 bit Data Descriptor */
255 #define GUCODE_SEL 5 /* User 64 bit Code Descriptor */
256 #define GPROC0_SEL 6 /* TSS for entering kernel etc */
257 /* slot 7 is second half of GPROC0_SEL */
258 #define GUGS32_SEL 8 /* User 32 bit GS Descriptor */
264 extern struct user_segment_descriptor gdt[];
265 extern struct soft_segment_descriptor gdt_segs[];
266 extern struct gate_descriptor *idt;
268 void lgdt(struct region_descriptor *rdp);
269 void sdtossd(struct user_segment_descriptor *sdp,
270 struct soft_segment_descriptor *ssdp);
271 void ssdtosd(struct soft_segment_descriptor *ssdp,
272 struct user_segment_descriptor *sdp);
273 void ssdtosyssd(struct soft_segment_descriptor *ssdp,
274 struct system_segment_descriptor *sdp);
278 #endif /* !_CPU_SEGMENTS_H_ */