1 /*-
2 * Copyright (c) 1989, 1990 William F. Jolitz
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * from: @(#)segments.h 7.1 (Berkeley) 5/9/91
34 * $FreeBSD$
35 */
36
37 #ifndef _MACHINE_SEGMENTS_H_
38 #define _MACHINE_SEGMENTS_H_
39
40 /*
41 * 386 Segmentation Data Structures and definitions
42 * William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
43 */
44
45 /*
46 * Selectors
47 */
48
49 #define ISPL(s) ((s)&3) /* what is the priority level of a selector */
50 #ifdef XEN
51 #define SEL_KPL 1 /* kernel priority level */
52 #else
53 #define SEL_KPL 0 /* kernel priority level */
54 #endif
55 #define SEL_UPL 3 /* user priority level */
56 #define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */
57 #define SEL_LDT 4 /* local descriptor table */
58 #define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */
59 #define LSEL(s,r) (((s)<<3) | SEL_LDT | r) /* a local selector */
60 #define GSEL(s,r) (((s)<<3) | r) /* a global selector */
61
62 /*
63 * Memory and System segment descriptors
64 */
65 struct segment_descriptor {
66 unsigned sd_lolimit:16 ; /* segment extent (lsb) */
67 unsigned sd_lobase:24 __packed; /* segment base address (lsb) */
68 unsigned sd_type:5 ; /* segment type */
69 unsigned sd_dpl:2 ; /* segment descriptor priority level */
70 unsigned sd_p:1 ; /* segment descriptor present */
71 unsigned sd_hilimit:4 ; /* segment extent (msb) */
72 unsigned sd_xx:2 ; /* unused */
73 unsigned sd_def32:1 ; /* default 32 vs 16 bit size */
74 unsigned sd_gran:1 ; /* limit granularity (byte/page units)*/
75 unsigned sd_hibase:8 ; /* segment base address (msb) */
76 } ;
77
78 #define USD_GETBASE(sd) (((sd)->sd_lobase) | (sd)->sd_hibase << 24)
79 #define USD_SETBASE(sd, b) (sd)->sd_lobase = (b); \
80 (sd)->sd_hibase = ((b) >> 24);
81 #define USD_GETLIMIT(sd) (((sd)->sd_lolimit) | (sd)->sd_hilimit << 16)
82 #define USD_SETLIMIT(sd, l) (sd)->sd_lolimit = (l); \
83 (sd)->sd_hilimit = ((l) >> 16);
84
85 /*
86 * Gate descriptors (e.g. indirect descriptors)
87 */
88 struct gate_descriptor {
89 unsigned gd_looffset:16 ; /* gate offset (lsb) */
90 unsigned gd_selector:16 ; /* gate segment selector */
91 unsigned gd_stkcpy:5 ; /* number of stack wds to cpy */
92 unsigned gd_xx:3 ; /* unused */
93 unsigned gd_type:5 ; /* segment type */
94 unsigned gd_dpl:2 ; /* segment descriptor priority level */
95 unsigned gd_p:1 ; /* segment descriptor present */
96 unsigned gd_hioffset:16 ; /* gate offset (msb) */
97 } ;
98
99 /*
100 * Generic descriptor
101 */
102 union descriptor {
103 struct segment_descriptor sd;
104 struct gate_descriptor gd;
105 };
106
107 /* system segments and gate types */
108 #define SDT_SYSNULL 0 /* system null */
109 #define SDT_SYS286TSS 1 /* system 286 TSS available */
110 #define SDT_SYSLDT 2 /* system local descriptor table */
111 #define SDT_SYS286BSY 3 /* system 286 TSS busy */
112 #define SDT_SYS286CGT 4 /* system 286 call gate */
113 #define SDT_SYSTASKGT 5 /* system task gate */
114 #define SDT_SYS286IGT 6 /* system 286 interrupt gate */
115 #define SDT_SYS286TGT 7 /* system 286 trap gate */
116 #define SDT_SYSNULL2 8 /* system null again */
117 #define SDT_SYS386TSS 9 /* system 386 TSS available */
118 #define SDT_SYSNULL3 10 /* system null again */
119 #define SDT_SYS386BSY 11 /* system 386 TSS busy */
120 #define SDT_SYS386CGT 12 /* system 386 call gate */
121 #define SDT_SYSNULL4 13 /* system null again */
122 #define SDT_SYS386IGT 14 /* system 386 interrupt gate */
123 #define SDT_SYS386TGT 15 /* system 386 trap gate */
124
125 /* memory segment types */
126 #define SDT_MEMRO 16 /* memory read only */
127 #define SDT_MEMROA 17 /* memory read only accessed */
128 #define SDT_MEMRW 18 /* memory read write */
129 #define SDT_MEMRWA 19 /* memory read write accessed */
130 #define SDT_MEMROD 20 /* memory read only expand dwn limit */
131 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
132 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */
133 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */
134 #define SDT_MEME 24 /* memory execute only */
135 #define SDT_MEMEA 25 /* memory execute only accessed */
136 #define SDT_MEMER 26 /* memory execute read */
137 #define SDT_MEMERA 27 /* memory execute read accessed */
138 #define SDT_MEMEC 28 /* memory execute only conforming */
139 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */
140 #define SDT_MEMERC 30 /* memory execute read conforming */
141 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */
142
143 /*
144 * Software definitions are in this convenient format,
145 * which are translated into inconvenient segment descriptors
146 * when needed to be used by the 386 hardware
147 */
148
149 struct soft_segment_descriptor {
150 unsigned ssd_base ; /* segment base address */
151 unsigned ssd_limit ; /* segment extent */
152 unsigned ssd_type:5 ; /* segment type */
153 unsigned ssd_dpl:2 ; /* segment descriptor priority level */
154 unsigned ssd_p:1 ; /* segment descriptor present */
155 unsigned ssd_xx:4 ; /* unused */
156 unsigned ssd_xx1:2 ; /* unused */
157 unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */
158 unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/
159 };
160
161 /*
162 * region descriptors, used to load gdt/idt tables before segments yet exist.
163 */
164 struct region_descriptor {
165 unsigned rd_limit:16; /* segment extent */
166 unsigned rd_base:32 __packed; /* base address */
167 };
168
169 /*
170 * Segment Protection Exception code bits
171 */
172
173 #define SEGEX_EXT 0x01 /* recursive or externally induced */
174 #define SEGEX_IDT 0x02 /* interrupt descriptor table */
175 #define SEGEX_TI 0x04 /* local descriptor table */
176 /* other bits are affected descriptor index */
177 #define SEGEX_IDX(s) (((s)>>3)&0x1fff)
178
179 /*
180 * Size of IDT table
181 */
182
183 #define NIDT 256 /* 32 reserved, 0x80 syscall, most are h/w */
184 #define NRSVIDT 32 /* reserved entries for cpu exceptions */
185
186 /*
187 * Entries in the Interrupt Descriptor Table (IDT)
188 */
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 */
210 #define IDT_DTRACE_RET 0x92 /* DTrace pid provider Interrupt Vector */
211
212 /*
213 * Entries in the Global Descriptor Table (GDT)
214 * Note that each 4 entries share a single 32 byte L1 cache line.
215 * Some of the fast syscall instructions require a specific order here.
216 */
217 #define GNULL_SEL 0 /* Null Descriptor */
218 #define GPRIV_SEL 1 /* SMP Per-Processor Private Data */
219 #define GUFS_SEL 2 /* User %fs Descriptor (order critical: 1) */
220 #define GUGS_SEL 3 /* User %gs Descriptor (order critical: 2) */
221 #define GCODE_SEL 4 /* Kernel Code Descriptor (order critical: 1) */
222 #define GDATA_SEL 5 /* Kernel Data Descriptor (order critical: 2) */
223 #define GUCODE_SEL 6 /* User Code Descriptor (order critical: 3) */
224 #define GUDATA_SEL 7 /* User Data Descriptor (order critical: 4) */
225 #define GBIOSLOWMEM_SEL 8 /* BIOS low memory access (must be entry 8) */
226 #define GPROC0_SEL 9 /* Task state process slot zero and up */
227 #define GLDT_SEL 10 /* Default User LDT */
228 #define GUSERLDT_SEL 11 /* User LDT */
229 #define GPANIC_SEL 12 /* Task state to consider panic from */
230 #define GBIOSCODE32_SEL 13 /* BIOS interface (32bit Code) */
231 #define GBIOSCODE16_SEL 14 /* BIOS interface (16bit Code) */
232 #define GBIOSDATA_SEL 15 /* BIOS interface (Data) */
233 #define GBIOSUTIL_SEL 16 /* BIOS interface (Utility) */
234 #define GBIOSARGS_SEL 17 /* BIOS interface (Arguments) */
235 #define GNDIS_SEL 18 /* For the NDIS layer */
236
237 #ifdef XEN
238 #define NGDT 9
239 #else
240 #define NGDT 19
241 #endif
242
243 /*
244 * Entries in the Local Descriptor Table (LDT)
245 */
246 #define LSYS5CALLS_SEL 0 /* forced by intel BCS */
247 #define LSYS5SIGR_SEL 1
248 #define L43BSDCALLS_SEL 2 /* notyet */
249 #define LUCODE_SEL 3
250 #define LSOL26CALLS_SEL 4 /* Solaris >= 2.6 system call gate */
251 #define LUDATA_SEL 5
252 /* separate stack, es,fs,gs sels ? */
253 /* #define LPOSIXCALLS_SEL 5*/ /* notyet */
254 #define LBSDICALLS_SEL 16 /* BSDI system call gate */
255 #define NLDT (LBSDICALLS_SEL + 1)
256
257 #ifdef _KERNEL
258 extern int _default_ldt;
259 #ifdef XEN
260 extern struct proc_ldt default_proc_ldt;
261 extern union descriptor *gdt;
262 extern union descriptor *ldt;
263 #else
264 extern union descriptor gdt[];
265 extern union descriptor ldt[NLDT];
266 #endif
267 extern struct soft_segment_descriptor gdt_segs[];
268 extern struct gate_descriptor *idt;
269 extern struct region_descriptor r_gdt, r_idt;
270
271 void lgdt(struct region_descriptor *rdp);
272 void sdtossd(struct segment_descriptor *sdp,
273 struct soft_segment_descriptor *ssdp);
274 void ssdtosd(struct soft_segment_descriptor *ssdp,
275 struct segment_descriptor *sdp);
276 #endif /* _KERNEL */
277
278 #endif /* !_MACHINE_SEGMENTS_H_ */
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