xref: /netbsd-src/sys/arch/amd64/include/segments.h (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: segments.h,v 1.19 2008/10/26 00:08:15 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
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.
21  *
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
32  * SUCH DAMAGE.
33  *
34  *	@(#)segments.h	7.1 (Berkeley) 5/9/91
35  */
36 
37 /*-
38  * Copyright (c) 1995, 1997
39  *	Charles M. Hannum.  All rights reserved.
40  * Copyright (c) 1989, 1990 William F. Jolitz
41  *
42  * This code is derived from software contributed to Berkeley by
43  * William Jolitz.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. All advertising materials mentioning features or use of this software
54  *    must display the following acknowledgement:
55  *	This product includes software developed by the University of
56  *	California, Berkeley and its contributors.
57  * 4. Neither the name of the University nor the names of its contributors
58  *    may be used to endorse or promote products derived from this software
59  *    without specific prior written permission.
60  *
61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71  * SUCH DAMAGE.
72  *
73  *	@(#)segments.h	7.1 (Berkeley) 5/9/91
74  */
75 
76 /*
77  * Adapted for NetBSD/amd64 by fvdl@wasabisystems.com.
78  */
79 
80 /*
81  * 386 Segmentation Data Structures and definitions
82  *	William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
83  */
84 
85 #ifndef _AMD64_SEGMENTS_H_
86 #define _AMD64_SEGMENTS_H_
87 
88 #ifdef __x86_64__
89 
90 #ifdef _KERNEL_OPT
91 #include "opt_xen.h"
92 #endif
93 
94 /*
95  * Selectors
96  */
97 
98 #define	ISPL(s)		((s) & SEL_RPL)	/* what is the priority level of a selector */
99 #ifdef XEN
100 #define	SEL_KPL		3		/* kernel privilege level */
101 #define	SEL_XPL		0		/* Xen Hypervisor privilege level */
102 #else
103 #define	SEL_KPL		0		/* kernel privilege level */
104 #endif
105 #define	SEL_UPL		3		/* user privilege level */
106 #define	SEL_RPL		3		/* requester's privilege level mask */
107 #define	ISLDT(s)	((s) & SEL_LDT)	/* is it local or global */
108 #define	SEL_LDT		4		/* local descriptor table */
109 
110 /* Dynamically allocated TSSs and LDTs start (byte offset) */
111 #define SYSSEL_START	(NGDT_MEM << 3)
112 #define DYNSEL_START	(SYSSEL_START + (NGDT_SYS << 4))
113 
114 /*
115  * These define the index not from the start of the GDT, but from
116  * the part of the GDT that they're allocated from.
117  * First NGDT_MEM entries are 8-byte descriptors for CS and DS.
118  * Next NGDT_SYS entries are 16-byte descriptors defining LDTs.
119  *
120  * The rest is 16-byte descriptors for TSS and LDT.
121  */
122 
123 #define	IDXSEL(s)	(((s) >> 3) & 0x1fff)
124 #define IDXDYNSEL(s)	((((s) & ~SEL_RPL) - DYNSEL_START) >> 4)
125 
126 #define	GSEL(s,r)	(((s) << 3) | r)
127 #define	GSYSSEL(s,r)	((((s) << 4) + SYSSEL_START) | r)
128 #define GDYNSEL(s,r)	((((s) << 4) + DYNSEL_START) | r | SEL_KPL)
129 
130 #define LSEL(s,r)	((s) | r | SEL_LDT)
131 
132 #define	USERMODE(c, f)		(ISPL(c) == SEL_UPL)
133 #ifdef XEN
134 /*
135  * As KPL == UPL, Xen emulate interrupt in kernel context by pushing
136  * a fake CS with XPL privilege
137  */
138 #define	KERNELMODE(c, f)	(ISPL(c) == SEL_XPL)
139 #else
140 #define	KERNELMODE(c, f)	(ISPL(c) == SEL_KPL)
141 #endif
142 
143 #ifndef _LOCORE
144 
145 /*
146  * Memory and System segment descriptors
147  */
148 
149 /*
150  * Below is used for TSS and LDT.
151  */
152 struct sys_segment_descriptor {
153 /*BITFIELDTYPE*/ uint64_t sd_lolimit:16;/* segment extent (lsb) */
154 /*BITFIELDTYPE*/ uint64_t sd_lobase:24;/* segment base address (lsb) */
155 /*BITFIELDTYPE*/ uint64_t sd_type:5;	/* segment type */
156 /*BITFIELDTYPE*/ uint64_t sd_dpl:2;	/* segment descriptor priority level */
157 /*BITFIELDTYPE*/ uint64_t sd_p:1;	/* segment descriptor present */
158 /*BITFIELDTYPE*/ uint64_t sd_hilimit:4;/* segment extent (msb) */
159 /*BITFIELDTYPE*/ uint64_t sd_xx1:3;	/* avl, long and def32 (not used) */
160 /*BITFIELDTYPE*/ uint64_t sd_gran:1;	/* limit granularity (byte/page) */
161 /*BITFIELDTYPE*/ uint64_t sd_hibase:40;/* segment base address (msb) */
162 /*BITFIELDTYPE*/ uint64_t sd_xx2:8;	/* reserved */
163 /*BITFIELDTYPE*/ uint64_t sd_zero:5;	/* must be zero */
164 /*BITFIELDTYPE*/ uint64_t sd_xx3:19;	/* reserved */
165 } __packed;
166 
167 /*
168  * Below is used for cs, ds, etc.
169  */
170 struct mem_segment_descriptor {
171 	unsigned sd_lolimit:16;         /* segment extent (lsb) */
172 	unsigned sd_lobase:24;          /* segment base address (lsb) */
173 	unsigned sd_type:5;             /* segment type */
174 	unsigned sd_dpl:2;              /* segment descriptor priority level */
175 	unsigned sd_p:1;                /* segment descriptor present */
176 	unsigned sd_hilimit:4;          /* segment extent (msb) */
177 	unsigned sd_avl:1;		/* available */
178 	unsigned sd_long:1;		/* long mode */
179 	unsigned sd_def32:1;            /* default 32 vs 16 bit size */
180 	unsigned sd_gran:1;             /* limit granularity (byte/page) */
181 	unsigned sd_hibase:8;           /* segment base address (msb) */
182 } __packed;
183 
184 /*
185  * Common part of the above structures. Used to walk descriptor tables.
186  */
187 struct common_segment_descriptor {
188 	unsigned sdc_lolimit:16;
189 	unsigned sdc_lobase:24;
190 	unsigned sdc_type:5;
191 	unsigned sdc_other:19;
192 } __packed;
193 
194 /*
195  * Gate descriptors (e.g. indirect descriptors)
196  */
197 struct gate_descriptor {
198 /*BITFIELDTYPE*/ uint64_t gd_looffset:16;/* gate offset (lsb) */
199 /*BITFIELDTYPE*/ uint64_t gd_selector:16;/* gate segment selector */
200 /*BITFIELDTYPE*/ uint64_t gd_ist:3;	/* IST select */
201 /*BITFIELDTYPE*/ uint64_t gd_xx1:5;	/* reserved */
202 /*BITFIELDTYPE*/ uint64_t gd_type:5;	/* segment type */
203 /*BITFIELDTYPE*/ uint64_t gd_dpl:2;	/* segment descriptor priority level */
204 /*BITFIELDTYPE*/ uint64_t gd_p:1;	/* segment descriptor present */
205 /*BITFIELDTYPE*/ uint64_t gd_hioffset:48;/* gate offset (msb) */
206 /*BITFIELDTYPE*/ uint64_t gd_xx2:8;	/* reserved */
207 /*BITFIELDTYPE*/ uint64_t gd_zero:5;	/* must be zero */
208 /*BITFIELDTYPE*/ uint64_t gd_xx3:19;	/* reserved */
209 } __packed;
210 
211 /*
212  * region descriptors, used to load gdt/idt tables before segments yet exist.
213  */
214 struct region_descriptor {
215 	uint16_t rd_limit;		/* segment extent */
216 	uint64_t rd_base;		/* base address  */
217 } __packed;
218 
219 #ifdef _KERNEL
220 #if 0
221 extern struct sys_segment_descriptor *ldt;
222 #endif
223 #ifdef XEN
224 extern struct trap_info *idt;
225 #else
226 extern struct gate_descriptor *idt;
227 #endif
228 extern char *gdtstore;
229 extern char *ldtstore;
230 
231 void setgate(struct gate_descriptor *, void *, int, int, int, int);
232 void unsetgate(struct gate_descriptor *);
233 void setregion(struct region_descriptor *, void *, uint16_t);
234 void set_sys_segment(struct sys_segment_descriptor *, void *, size_t,
235 			  int, int, int);
236 void set_mem_segment(struct mem_segment_descriptor *, void *, size_t,
237 			  int, int, int, int, int);
238 void cpu_init_idt(void);
239 
240 #if !defined(XEN)
241 void idt_init(void);
242 void idt_vec_reserve(int);
243 int idt_vec_alloc(int, int);
244 void idt_vec_set(int, void (*)(void));
245 void idt_vec_free(int);
246 #endif
247 
248 struct lwp;
249 int memseg_baseaddr(struct lwp *, uint64_t, char *, int, uint64_t *);
250 int valid_user_selector(struct lwp *, uint64_t, char *, int);
251 
252 
253 #endif /* _KERNEL */
254 
255 #endif /* !_LOCORE */
256 
257 /* system segments and gate types */
258 #define	SDT_SYSNULL	 0	/* system null */
259 #define	SDT_SYS286TSS	 1	/* system 286 TSS available */
260 #define	SDT_SYSLDT	 2	/* system local descriptor table */
261 #define	SDT_SYS286BSY	 3	/* system 286 TSS busy */
262 #define	SDT_SYS286CGT	 4	/* system 286 call gate */
263 #define	SDT_SYSTASKGT	 5	/* system task gate */
264 #define	SDT_SYS286IGT	 6	/* system 286 interrupt gate */
265 #define	SDT_SYS286TGT	 7	/* system 286 trap gate */
266 #define	SDT_SYSNULL2	 8	/* system null again */
267 #define	SDT_SYS386TSS	 9	/* system 386 TSS available */
268 #define	SDT_SYSNULL3	10	/* system null again */
269 #define	SDT_SYS386BSY	11	/* system 386 TSS busy */
270 #define	SDT_SYS386CGT	12	/* system 386 call gate */
271 #define	SDT_SYSNULL4	13	/* system null again */
272 #define	SDT_SYS386IGT	14	/* system 386 interrupt gate */
273 #define	SDT_SYS386TGT	15	/* system 386 trap gate */
274 
275 /* memory segment types */
276 #define	SDT_MEMRO	16	/* memory read only */
277 #define	SDT_MEMROA	17	/* memory read only accessed */
278 #define	SDT_MEMRW	18	/* memory read write */
279 #define	SDT_MEMRWA	19	/* memory read write accessed */
280 #define	SDT_MEMROD	20	/* memory read only expand dwn limit */
281 #define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
282 #define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
283 #define	SDT_MEMRWDA	23	/* memory read write expand dwn limit acessed */
284 #define	SDT_MEME	24	/* memory execute only */
285 #define	SDT_MEMEA	25	/* memory execute only accessed */
286 #define	SDT_MEMER	26	/* memory execute read */
287 #define	SDT_MEMERA	27	/* memory execute read accessed */
288 #define	SDT_MEMEC	28	/* memory execute only conforming */
289 #define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
290 #define	SDT_MEMERC	30	/* memory execute read conforming */
291 #define	SDT_MEMERAC	31	/* memory execute read accessed conforming */
292 
293 /* is memory segment descriptor pointer ? */
294 #define ISMEMSDP(s)	((s->d_type) >= SDT_MEMRO && \
295 			 (s->d_type) <= SDT_MEMERAC)
296 
297 /* is 286 gate descriptor pointer ? */
298 #define IS286GDP(s)	((s->d_type) >= SDT_SYS286CGT && \
299 			 (s->d_type) < SDT_SYS286TGT)
300 
301 /* is 386 gate descriptor pointer ? */
302 #define IS386GDP(s)	((s->d_type) >= SDT_SYS386CGT && \
303 			 (s->d_type) < SDT_SYS386TGT)
304 
305 /* is gate descriptor pointer ? */
306 #define ISGDP(s)	(IS286GDP(s) || IS386GDP(s))
307 
308 /* is segment descriptor pointer ? */
309 #define ISSDP(s)	(ISMEMSDP(s) || !ISGDP(s))
310 
311 /* is system segment descriptor pointer ? */
312 #define ISSYSSDP(s)	(!ISMEMSDP(s) && !ISGDP(s))
313 
314 /*
315  * Segment Protection Exception code bits
316  */
317 #define	SEGEX_EXT	0x01	/* recursive or externally induced */
318 #define	SEGEX_IDT	0x02	/* interrupt descriptor table */
319 #define	SEGEX_TI	0x04	/* local descriptor table */
320 
321 /*
322  * Entries in the Interrupt Descriptor Table (IDT)
323  */
324 #define	NIDT	256
325 #define	NRSVIDT	32		/* reserved entries for CPU exceptions */
326 
327 /*
328  * Entries in the Global Descriptor Table (GDT)
329  * The code and data descriptors must come first. There
330  * are NGDT_MEM of them.
331  *
332  * Then come the predefined LDT (and possibly TSS) descriptors.
333  * There are NGDT_SYS of them.
334  */
335 #define	GNULL_SEL	0	/* Null descriptor */
336 #define	GCODE_SEL	1	/* Kernel code descriptor */
337 #define	GDATA_SEL	2	/* Kernel data descriptor */
338 #define	GUCODE_SEL	3	/* User code descriptor */
339 #define	GUDATA_SEL	4	/* User data descriptor */
340 #define	GAPM32CODE_SEL	5
341 #define	GAPM16CODE_SEL	6
342 #define	GAPMDATA_SEL	7
343 #define	GBIOSCODE_SEL	8
344 #define	GBIOSDATA_SEL	9
345 #define GPNPBIOSCODE_SEL 10
346 #define GPNPBIOSDATA_SEL 11
347 #define GPNPBIOSSCRATCH_SEL 12
348 #define GPNPBIOSTRAMP_SEL 13
349 #define GUCODE32_SEL	14
350 #define GUDATA32_SEL	15
351 #define NGDT_MEM 16
352 
353 #define	GLDT_SEL	0	/* Default LDT descriptor */
354 #define NGDT_SYS	1
355 
356 #define GDT_ADDR_MEM(s,i)	\
357     ((struct mem_segment_descriptor *)((s) + ((i) << 3)))
358 #define GDT_ADDR_SYS(s,i)	\
359    ((struct sys_segment_descriptor *)((s) + (((i) << 4) + SYSSEL_START)))
360 
361 /*
362  * Byte offsets in the Local Descriptor Table (LDT)
363  * Strange order because of syscall/sysret insns
364  */
365 #define	LSYS5CALLS_SEL	0	/* iBCS system call gate */
366 #define LUCODE32_SEL	8	/* 32 bit user code descriptor */
367 #define	LUDATA_SEL	16	/* User data descriptor */
368 #define	LUCODE_SEL	24	/* User code descriptor */
369 #define	LSOL26CALLS_SEL	32	/* Solaris 2.6 system call gate */
370 #define LUDATA32_SEL	56	/* 32 bit user data descriptor (needed?)*/
371 #define	LBSDICALLS_SEL	128	/* BSDI system call gate */
372 
373 #define LDT_SIZE	144
374 
375 #define LSYSRETBASE_SEL	LUCODE32_SEL
376 
377 /*
378  * Checks for valid user selectors. If USER_LDT ever gets implemented
379  * for amd64, these must check the ldt length and SEL_UPL if a user
380  * ldt is active.
381  */
382 #define VALID_USER_DSEL32(s) \
383     (((s) & 0xffff) == GSEL(GUDATA32_SEL, SEL_UPL) || \
384      ((s) & 0xffff) == LSEL(LUDATA32_SEL, SEL_UPL))
385 #if 0 /* not used */
386 #define VALID_USER_CSEL32(s) \
387     ((s) == GSEL(GUCODE32_SEL, SEL_UPL) || (s) == LSEL(LUCODE32_SEL, SEL_UPL))
388 #endif
389 
390 #define VALID_USER_CSEL(s) \
391     ((s) == GSEL(GUCODE_SEL, SEL_UPL) || (s) == LSEL(LUCODE_SEL, SEL_UPL))
392 #define VALID_USER_DSEL(s) \
393     ((s) == GSEL(GUDATA_SEL, SEL_UPL) || (s) == LSEL(LUDATA_SEL, SEL_UPL))
394 
395 #else	/*	__x86_64__	*/
396 
397 #include <i386/segments.h>
398 
399 #endif	/*	__x86_64__	*/
400 
401 #endif /* _AMD64_SEGMENTS_H_ */
402