xref: /freebsd/sys/amd64/include/segments.h (revision 13014ca04aad1931d41958b56f71a2c65b9a7a2c)
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  * AMD64 Segmentation Data Structures and definitions
42  */
43 
44 /*
45  * Selectors
46  */
47 
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 */
57 
58 /*
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.
62  */
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) */
75 } __packed;
76 
77 /*
78  * System segment descriptors (128 bit wide)
79  */
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) */
90 	u_int64_t sd_xx1:8;
91 	u_int64_t sd_mbz:5;		/* MUST be zero */
92 	u_int64_t sd_xx2:19;
93 } __packed;
94 
95 /*
96  * Gate descriptors (e.g. indirect descriptors, trap, interrupt etc. 128 bit)
97  * Only interrupt and trap gates have gd_ist.
98  */
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) */
108 	u_int64_t sd_xx1:32;
109 } __packed;
110 
111 	/* system segments and gate types */
112 #define	SDT_SYSNULL	 0	/* system null */
113 #define	SDT_SYSLDT	 2	/* system 64 bit local descriptor table */
114 #define	SDT_SYSTSS	 9	/* system available 64 bit TSS */
115 #define	SDT_SYSBSY	11	/* system busy 64 bit TSS */
116 #define	SDT_SYSCGT	12	/* system 64 bit call gate */
117 #define	SDT_SYSIGT	14	/* system 64 bit interrupt gate */
118 #define	SDT_SYSTGT	15	/* system 64 bit trap gate */
119 
120 	/* memory segment types */
121 #define	SDT_MEMRO	16	/* memory read only */
122 #define	SDT_MEMROA	17	/* memory read only accessed */
123 #define	SDT_MEMRW	18	/* memory read write */
124 #define	SDT_MEMRWA	19	/* memory read write accessed */
125 #define	SDT_MEMROD	20	/* memory read only expand dwn limit */
126 #define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
127 #define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
128 #define	SDT_MEMRWDA	23	/* memory read write expand dwn limit accessed */
129 #define	SDT_MEME	24	/* memory execute only */
130 #define	SDT_MEMEA	25	/* memory execute only accessed */
131 #define	SDT_MEMER	26	/* memory execute read */
132 #define	SDT_MEMERA	27	/* memory execute read accessed */
133 #define	SDT_MEMEC	28	/* memory execute only conforming */
134 #define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
135 #define	SDT_MEMERC	30	/* memory execute read conforming */
136 #define	SDT_MEMERAC	31	/* memory execute read accessed conforming */
137 
138 /*
139  * Software definitions are in this convenient format,
140  * which are translated into inconvenient segment descriptors
141  * when needed to be used by the 386 hardware
142  */
143 
144 struct	soft_segment_descriptor {
145 	unsigned long ssd_base;		/* segment base address  */
146 	unsigned long ssd_limit;	/* segment extent */
147 	unsigned long ssd_type:5;	/* segment type */
148 	unsigned long ssd_dpl:2;	/* segment descriptor priority level */
149 	unsigned long ssd_p:1;		/* segment descriptor present */
150 	unsigned long ssd_long:1;	/* long mode (for %cs) */
151 	unsigned long ssd_def32:1;	/* default 32 vs 16 bit size */
152 	unsigned long ssd_gran:1;	/* limit granularity (byte/page units)*/
153 } __packed;
154 
155 /*
156  * region descriptors, used to load gdt/idt tables before segments yet exist.
157  */
158 struct region_descriptor {
159 	unsigned long rd_limit:16;		/* segment extent */
160 	unsigned long rd_base:64 __packed;	/* base address  */
161 } __packed;
162 
163 /*
164  * Size of IDT table
165  */
166 #define	NIDT	256		/* 32 reserved, 16 h/w, 0 s/w, linux's 0x80 */
167 #define	NRSVIDT	32		/* reserved entries for cpu exceptions */
168 
169 /*
170  * Entries in the Interrupt Descriptor Table (IDT)
171  */
172 #define	IDT_DE		0	/* #DE: Divide Error */
173 #define	IDT_DB		1	/* #DB: Debug */
174 #define	IDT_NMI		2	/* Nonmaskable External Interrupt */
175 #define	IDT_BP		3	/* #BP: Breakpoint */
176 #define	IDT_OF		4	/* #OF: Overflow */
177 #define	IDT_BR		5	/* #BR: Bound Range Exceeded */
178 #define	IDT_UD		6	/* #UD: Undefined/Invalid Opcode */
179 #define	IDT_NM		7	/* #NM: No Math Coprocessor */
180 #define	IDT_DF		8	/* #DF: Double Fault */
181 #define	IDT_FPUGP	9	/* Coprocessor Segment Overrun */
182 #define	IDT_TS		10	/* #TS: Invalid TSS */
183 #define	IDT_NP		11	/* #NP: Segment Not Present */
184 #define	IDT_SS		12	/* #SS: Stack Segment Fault */
185 #define	IDT_GP		13	/* #GP: General Protection Fault */
186 #define	IDT_PF		14	/* #PF: Page Fault */
187 #define	IDT_MF		16	/* #MF: FPU Floating-Point Error */
188 #define	IDT_AC		17	/* #AC: Alignment Check */
189 #define	IDT_MC		18	/* #MC: Machine Check */
190 #define	IDT_XF		19	/* #XF: SIMD Floating-Point Exception */
191 #define	IDT_IO_INTS	NRSVIDT	/* Base of IDT entries for I/O interrupts. */
192 #define	IDT_SYSCALL	0x80	/* System Call Interrupt Vector */
193 
194 /*
195  * Entries in the Global Descriptor Table (GDT)
196  */
197 #define	GNULL_SEL	0	/* Null Descriptor */
198 #define	GCODE_SEL	1	/* Kernel Code Descriptor */
199 #define	GDATA_SEL	2	/* Kernel Data Descriptor */
200 #define	GUCODE32_SEL	3	/* User 32 bit code Descriptor */
201 #define	GUDATA_SEL	4	/* User 32/64 bit Data Descriptor */
202 #define	GUCODE_SEL	5	/* User 64 bit Code Descriptor */
203 #define	GPROC0_SEL	6	/* TSS for entering kernel etc */
204 /* slot 7 is second half of GPROC0_SEL */
205 #define	GUGS32_SEL	8	/* User 32 bit GS Descriptor */
206 #define	NGDT 		9
207 
208 #ifdef _KERNEL
209 extern struct user_segment_descriptor gdt[];
210 extern struct soft_segment_descriptor gdt_segs[];
211 extern struct gate_descriptor *idt;
212 extern struct region_descriptor r_gdt, r_idt;
213 
214 void	lgdt(struct region_descriptor *rdp);
215 void	sdtossd(struct user_segment_descriptor *sdp,
216 	    struct soft_segment_descriptor *ssdp);
217 void	ssdtosd(struct soft_segment_descriptor *ssdp,
218 	    struct user_segment_descriptor *sdp);
219 void	ssdtosyssd(struct soft_segment_descriptor *ssdp,
220 	    struct system_segment_descriptor *sdp);
221 #endif /* _KERNEL */
222 
223 #endif /* !_MACHINE_SEGMENTS_H_ */
224