segments.h revision 190620
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: head/sys/amd64/include/segments.h 190620 2009-04-01 13:09:26Z kib $
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 */
63struct	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 */
80struct	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 */
99struct	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/*
112 * Generic descriptor
113 */
114union	descriptor	{
115	struct	user_segment_descriptor sd;
116	struct	gate_descriptor gd;
117};
118
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 */
136
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 */
154
155/*
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
159 */
160
161struct	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)*/
170} __packed;
171
172/*
173 * region descriptors, used to load gdt/idt tables before segments yet exist.
174 */
175struct region_descriptor {
176	unsigned long rd_limit:16;		/* segment extent */
177	unsigned long rd_base:64 __packed;	/* base address  */
178} __packed;
179
180/*
181 * Size of IDT table
182 */
183#define	NIDT	256		/* 32 reserved, 16 h/w, 0 s/w, linux's 0x80 */
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
211/*
212 * Entries in the Global Descriptor Table (GDT)
213 */
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 */
227#define	NGDT 		13
228
229#ifdef _KERNEL
230extern struct user_segment_descriptor gdt[];
231extern struct soft_segment_descriptor gdt_segs[];
232extern struct gate_descriptor *idt;
233extern struct region_descriptor r_gdt, r_idt;
234
235void	lgdt(struct region_descriptor *rdp);
236void	sdtossd(struct user_segment_descriptor *sdp,
237	    struct soft_segment_descriptor *ssdp);
238void	ssdtosd(struct soft_segment_descriptor *ssdp,
239	    struct user_segment_descriptor *sdp);
240void	ssdtosyssd(struct soft_segment_descriptor *ssdp,
241	    struct system_segment_descriptor *sdp);
242void	update_gdt_gsbase(struct thread *td, uint32_t base);
243void	update_gdt_fsbase(struct thread *td, uint32_t base);
244
245#endif /* _KERNEL */
246
247#endif /* !_MACHINE_SEGMENTS_H_ */
248