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
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#)segments.h 7.1 (Berkeley) 5/9/91
35 * $FreeBSD: src/sys/i386/include/segments.h,v 1.24 1999/12/29 04:33:07 peter Exp $
38 #ifndef _CPU_SEGMENTS_H_
39 #define _CPU_SEGMENTS_H_
46 * x86_64 Segmentation Data Structures and definitions
53 #define SEL_RPL_MASK 3 /* requester's privilege level mask */
54 #define ISPL(s) ((s) & SEL_RPL_MASK) /* privilege level of a selector */
55 #define SEL_KPL 0 /* kernel privilege level */
56 #define SEL_UPL 3 /* user privilege level */
57 #define SEL_LDT 4 /* local descriptor table */
58 #define ISLDT(s) ((s) & SEL_LDT) /* is it local or global */
59 #define IDXSEL(s) (((s) >> 3) & 0x1fff) /* index of selector */
60 #define LSEL(s,r) (((s) << 3) | r | SEL_LDT) /* a local selector */
61 #define GSEL(s,r) (((s) << 3) | r) /* a global selector */
66 * User segment descriptors (%cs, %ds etc for compatibility apps. 64 bit wide)
67 * For long-mode apps, %cs only has the conforming bit in sd_type, the sd_dpl,
68 * sd_p, sd_l and sd_def32 which must be zero). %ds only has sd_p.
70 struct user_segment_descriptor {
71 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
72 u_int64_t sd_lobase:24; /* segment base address (lsb) */
73 u_int64_t sd_type:5; /* segment type */
74 u_int64_t sd_dpl:2; /* segment descriptor priority level */
75 u_int64_t sd_p:1; /* segment descriptor present */
76 u_int64_t sd_hilimit:4; /* segment extent (msb) */
77 u_int64_t sd_xx:1; /* unused */
78 u_int64_t sd_long:1; /* long mode (cs only) */
79 u_int64_t sd_def32:1; /* default 32 vs 16 bit size */
80 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
81 u_int64_t sd_hibase:8; /* segment base address (msb) */
85 * System segment descriptors (128 bit wide)
87 struct system_segment_descriptor {
88 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
89 u_int64_t sd_lobase:24; /* segment base address (lsb) */
90 u_int64_t sd_type:5; /* segment type */
91 u_int64_t sd_dpl:2; /* segment descriptor priority level */
92 u_int64_t sd_p:1; /* segment descriptor present */
93 u_int64_t sd_hilimit:4; /* segment extent (msb) */
94 u_int64_t sd_xx0:3; /* unused */
95 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
96 u_int64_t sd_hibase:40 __packed;/* segment base address (msb) */
98 u_int64_t sd_mbz:5; /* MUST be zero */
103 * Gate descriptors (e.g. indirect descriptors, trap, interrupt etc. 128 bit)
104 * Only interrupt and trap gates have gd_ist.
106 struct gate_descriptor {
107 u_int64_t gd_looffset:16; /* gate offset (lsb) */
108 u_int64_t gd_selector:16; /* gate segment selector */
109 u_int64_t gd_ist:3; /* IST table index */
110 u_int64_t gd_xx:5; /* unused */
111 u_int64_t gd_type:5; /* segment type */
112 u_int64_t gd_dpl:2; /* segment descriptor priority level */
113 u_int64_t gd_p:1; /* segment descriptor present */
114 u_int64_t gd_hioffset:48 __packed; /* gate offset (msb) */
120 /* system segments and gate types */
121 #define SDT_SYSNULL 0 /* system null */
122 #define SDT_SYS286TSS 1 /* system 286 TSS available */
123 #define SDT_SYSLDT 2 /* system 64-bit local descriptor table */
124 #define SDT_SYS286BSY 3 /* system 286 TSS busy */
125 #define SDT_SYS286CGT 4 /* system 286 call gate */
126 #define SDT_SYSTASKGT 5 /* system task gate */
127 #define SDT_SYS286IGT 6 /* system 286 interrupt gate */
128 #define SDT_SYS286TGT 7 /* system 286 trap gate */
129 #define SDT_SYSNULL2 8 /* system null again */
130 #define SDT_SYSTSS 9 /* system 64-bit TSS available */
131 #define SDT_SYSNULL3 10 /* system null again */
132 #define SDT_SYSBSY 11 /* system 64-bit TSS busy */
133 #define SDT_SYSCGT 12 /* system 64-bit call gate */
134 #define SDT_SYSNULL4 13 /* system null again */
135 #define SDT_SYSIGT 14 /* system 64-bit interrupt gate */
136 #define SDT_SYSTGT 15 /* system 64-bit trap gate */
138 /* memory segment types */
139 #define SDT_MEMRO 16 /* memory read only */
140 #define SDT_MEMROA 17 /* memory read only accessed */
141 #define SDT_MEMRW 18 /* memory read write */
142 #define SDT_MEMRWA 19 /* memory read write accessed */
143 #define SDT_MEMROD 20 /* memory read only expand dwn limit */
144 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
145 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */
146 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */
147 #define SDT_MEME 24 /* memory execute only */
148 #define SDT_MEMEA 25 /* memory execute only accessed */
149 #define SDT_MEMER 26 /* memory execute read */
150 #define SDT_MEMERA 27 /* memory execute read accessed */
151 #define SDT_MEMEC 28 /* memory execute only conforming */
152 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */
153 #define SDT_MEMERC 30 /* memory execute read conforming */
154 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */
159 struct tls_info info[2];
163 * Software definitions are in this convenient format,
164 * which are translated into inconvenient segment descriptors
165 * when needed to be used by the x86 hardware.
168 struct soft_segment_descriptor {
169 uint64_t ssd_base; /* segment base address */
170 uint64_t ssd_limit; /* segment extent */
171 uint64_t ssd_type:5; /* segment type */
172 uint64_t ssd_dpl:2; /* segment descriptor priority level */
173 uint64_t ssd_p:1; /* segment descriptor present */
174 uint64_t ssd_long:1; /* long mode (for %cs) */
175 uint64_t ssd_def32:1; /* default 32 vs 16 bit size */
176 uint64_t ssd_gran:1; /* limit granularity (byte/page units)*/
180 * region descriptors, used to load gdt/idt tables before segments yet exist.
182 struct region_descriptor {
183 uint64_t rd_limit:16; /* segment extent */
184 uint64_t rd_base:64 __packed; /* base address */
190 * Segment Protection Exception code bits
193 #define SEGEX_EXT 0x01 /* recursive or externally induced */
194 #define SEGEX_IDT 0x02 /* interrupt descriptor table */
195 #define SEGEX_TI 0x04 /* local descriptor table */
196 /* other bits are affected descriptor index */
197 #define SEGEX_IDX(s) (((s) >> 3) & 0x1fff)
200 * Size of the IDT table.
202 #define NIDT 256 /* we use them all */
204 * Entries in the Interrupt Descriptor Table (IDT)
206 #define IDT_DE 0 /* #DE: Divide Error */
207 #define IDT_DB 1 /* #DB: Debug */
208 #define IDT_NMI 2 /* Nonmaskable External Interrupt */
209 #define IDT_BP 3 /* #BP: Breakpoint */
210 #define IDT_OF 4 /* #OF: Overflow */
211 #define IDT_BR 5 /* #BR: Bound Range Exceeded */
212 #define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */
213 #define IDT_NM 7 /* #NM: No Math Coprocessor */
214 #define IDT_DF 8 /* #DF: Double Fault */
215 #define IDT_FPUGP 9 /* Coprocessor Segment Overrun */
216 #define IDT_TS 10 /* #TS: Invalid TSS */
217 #define IDT_NP 11 /* #NP: Segment Not Present */
218 #define IDT_SS 12 /* #SS: Stack Segment Fault */
219 #define IDT_GP 13 /* #GP: General Protection Fault */
220 #define IDT_PF 14 /* #PF: Page Fault */
221 #define IDT_MF 16 /* #MF: FPU Floating-Point Error */
222 #define IDT_AC 17 /* #AC: Alignment Check */
223 #define IDT_MC 18 /* #MC: Machine Check */
224 #define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
225 #define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
226 #define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
229 * Entries in the Global Descriptor Table (GDT)
231 * NOTE 1: Due to quirks in Intel's VMX implementation, the GDT
232 * limit is set to 0xFFFF (representing 65536 bytes) on
233 * VM exit. Rather then have to do a heavy-weight reload,
234 * we just maximally-size the table.
236 #define GNULL_SEL 0 /* Null Descriptor */
237 #define GCODE_SEL 1 /* Kernel Code Descriptor */
238 #define GDATA_SEL 2 /* Kernel Data Descriptor */
239 #define GUCODE32_SEL 3 /* User 32 bit Code Descriptor */
240 #define GUDATA_SEL 4 /* User 32/64 bit Data Descriptor */
241 #define GUCODE_SEL 5 /* User 64 bit Code Descriptor */
242 #define GPROC0_SEL 6 /* TSS for entering kernel etc */
243 /* slot 7 is second half of GPROC0_SEL */
244 #define GUGS32_SEL 8 /* User 32 bit GS Descriptor */
246 #define MAXGDT_LIMIT 65536 /* (see note 1 above) */
247 #define MAXGDT_COUNT (MAXGDT_LIMIT / sizeof(struct user_segment_descriptor))
252 extern struct soft_segment_descriptor gdt_segs[];
253 extern struct gate_descriptor idt_arr[MAXCPU][NIDT];
254 extern struct region_descriptor r_idt_arr[];
255 extern struct region_descriptor r_gdt;
256 extern struct user_segment_descriptor gdt_cpu0[MAXGDT_COUNT];
258 void lgdt(struct region_descriptor *rdp);
259 void sdtossd(struct user_segment_descriptor *sdp,
260 struct soft_segment_descriptor *ssdp);
261 void ssdtosd(struct soft_segment_descriptor *ssdp,
262 struct user_segment_descriptor *sdp);
263 void ssdtosyssd(struct soft_segment_descriptor *ssdp,
264 struct system_segment_descriptor *sdp);
269 #endif /* !_CPU_SEGMENTS_H_ */