xref: /netbsd-src/sys/arch/amd64/include/segments.h (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: segments.h,v 1.21 2010/09/05 20:14:40 chs 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  * Generic descriptor
213  */
214 union descriptor {
215 	struct mem_segment_descriptor sd;
216 	uint32_t raw[2];
217 	uint64_t raw64;
218 } __packed;
219 
220 /*
221  * region descriptors, used to load gdt/idt tables before segments yet exist.
222  */
223 struct region_descriptor {
224 	uint16_t rd_limit;		/* segment extent */
225 	uint64_t rd_base;		/* base address  */
226 } __packed;
227 
228 #ifdef _KERNEL
229 #if 0
230 extern struct sys_segment_descriptor *ldt;
231 #endif
232 #ifdef XEN
233 extern struct trap_info *idt;
234 #else
235 extern struct gate_descriptor *idt;
236 #endif
237 extern char *gdtstore;
238 extern char *ldtstore;
239 
240 void setgate(struct gate_descriptor *, void *, int, int, int, int);
241 void unsetgate(struct gate_descriptor *);
242 void setregion(struct region_descriptor *, void *, uint16_t);
243 void set_sys_segment(struct sys_segment_descriptor *, void *, size_t,
244 			  int, int, int);
245 void set_mem_segment(struct mem_segment_descriptor *, void *, size_t,
246 			  int, int, int, int, int);
247 void cpu_init_idt(void);
248 void update_descriptor(void *, void *);
249 
250 #if !defined(XEN)
251 void idt_init(void);
252 void idt_vec_reserve(int);
253 int idt_vec_alloc(int, int);
254 void idt_vec_set(int, void (*)(void));
255 void idt_vec_free(int);
256 #endif
257 
258 struct lwp;
259 int memseg_baseaddr(struct lwp *, uint64_t, char *, int, uint64_t *);
260 int valid_user_selector(struct lwp *, uint64_t, char *, int);
261 void cpu_fsgs_zero(struct lwp *);
262 void cpu_fsgs_reload(struct lwp *, int, int);
263 
264 #endif /* _KERNEL */
265 
266 #endif /* !_LOCORE */
267 
268 /* system segments and gate types */
269 #define	SDT_SYSNULL	 0	/* system null */
270 #define	SDT_SYS286TSS	 1	/* system 286 TSS available */
271 #define	SDT_SYSLDT	 2	/* system local descriptor table */
272 #define	SDT_SYS286BSY	 3	/* system 286 TSS busy */
273 #define	SDT_SYS286CGT	 4	/* system 286 call gate */
274 #define	SDT_SYSTASKGT	 5	/* system task gate */
275 #define	SDT_SYS286IGT	 6	/* system 286 interrupt gate */
276 #define	SDT_SYS286TGT	 7	/* system 286 trap gate */
277 #define	SDT_SYSNULL2	 8	/* system null again */
278 #define	SDT_SYS386TSS	 9	/* system 386 TSS available */
279 #define	SDT_SYSNULL3	10	/* system null again */
280 #define	SDT_SYS386BSY	11	/* system 386 TSS busy */
281 #define	SDT_SYS386CGT	12	/* system 386 call gate */
282 #define	SDT_SYSNULL4	13	/* system null again */
283 #define	SDT_SYS386IGT	14	/* system 386 interrupt gate */
284 #define	SDT_SYS386TGT	15	/* system 386 trap gate */
285 
286 /* memory segment types */
287 #define	SDT_MEMRO	16	/* memory read only */
288 #define	SDT_MEMROA	17	/* memory read only accessed */
289 #define	SDT_MEMRW	18	/* memory read write */
290 #define	SDT_MEMRWA	19	/* memory read write accessed */
291 #define	SDT_MEMROD	20	/* memory read only expand dwn limit */
292 #define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
293 #define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
294 #define	SDT_MEMRWDA	23	/* memory read write expand dwn limit acessed */
295 #define	SDT_MEME	24	/* memory execute only */
296 #define	SDT_MEMEA	25	/* memory execute only accessed */
297 #define	SDT_MEMER	26	/* memory execute read */
298 #define	SDT_MEMERA	27	/* memory execute read accessed */
299 #define	SDT_MEMEC	28	/* memory execute only conforming */
300 #define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
301 #define	SDT_MEMERC	30	/* memory execute read conforming */
302 #define	SDT_MEMERAC	31	/* memory execute read accessed conforming */
303 
304 /* is memory segment descriptor pointer ? */
305 #define ISMEMSDP(s)	((s->d_type) >= SDT_MEMRO && \
306 			 (s->d_type) <= SDT_MEMERAC)
307 
308 /* is 286 gate descriptor pointer ? */
309 #define IS286GDP(s)	((s->d_type) >= SDT_SYS286CGT && \
310 			 (s->d_type) < SDT_SYS286TGT)
311 
312 /* is 386 gate descriptor pointer ? */
313 #define IS386GDP(s)	((s->d_type) >= SDT_SYS386CGT && \
314 			 (s->d_type) < SDT_SYS386TGT)
315 
316 /* is gate descriptor pointer ? */
317 #define ISGDP(s)	(IS286GDP(s) || IS386GDP(s))
318 
319 /* is segment descriptor pointer ? */
320 #define ISSDP(s)	(ISMEMSDP(s) || !ISGDP(s))
321 
322 /* is system segment descriptor pointer ? */
323 #define ISSYSSDP(s)	(!ISMEMSDP(s) && !ISGDP(s))
324 
325 /*
326  * Segment Protection Exception code bits
327  */
328 #define	SEGEX_EXT	0x01	/* recursive or externally induced */
329 #define	SEGEX_IDT	0x02	/* interrupt descriptor table */
330 #define	SEGEX_TI	0x04	/* local descriptor table */
331 
332 /*
333  * Entries in the Interrupt Descriptor Table (IDT)
334  */
335 #define	NIDT	256
336 #define	NRSVIDT	32		/* reserved entries for CPU exceptions */
337 
338 /*
339  * Entries in the Global Descriptor Table (GDT)
340  * The code and data descriptors must come first. There
341  * are NGDT_MEM of them.
342  *
343  * Then come the predefined LDT (and possibly TSS) descriptors.
344  * There are NGDT_SYS of them.
345  */
346 #define	GNULL_SEL	0	/* Null descriptor */
347 #define	GCODE_SEL	1	/* Kernel code descriptor */
348 #define	GDATA_SEL	2	/* Kernel data descriptor */
349 #define	GUCODE_SEL	3	/* User code descriptor */
350 #define	GUDATA_SEL	4	/* User data descriptor */
351 #define	GAPM32CODE_SEL	5
352 #define	GAPM16CODE_SEL	6
353 #define	GAPMDATA_SEL	7
354 #define	GBIOSCODE_SEL	8
355 #define	GBIOSDATA_SEL	9
356 #define GPNPBIOSCODE_SEL 10
357 #define GPNPBIOSDATA_SEL 11
358 #define GPNPBIOSSCRATCH_SEL 12
359 #define GPNPBIOSTRAMP_SEL 13
360 #define GUCODE32_SEL	14
361 #define GUDATA32_SEL	15
362 #define GUFS_SEL	16	/* 32-bit Per-thread %fs */
363 #define GUGS_SEL	17	/* 32-bit Per-thread %gs */
364 #define NGDT_MEM 18
365 
366 #define	GLDT_SEL	0	/* Default LDT descriptor */
367 #define NGDT_SYS	1
368 
369 #define GDT_ADDR_MEM(s,i)	\
370     ((struct mem_segment_descriptor *)((s) + ((i) << 3)))
371 #define GDT_ADDR_SYS(s,i)	\
372    ((struct sys_segment_descriptor *)((s) + (((i) << 4) + SYSSEL_START)))
373 
374 /*
375  * Byte offsets in the Local Descriptor Table (LDT)
376  * Strange order because of syscall/sysret insns
377  */
378 #define	LSYS5CALLS_SEL	0	/* iBCS system call gate */
379 #define LUCODE32_SEL	8	/* 32 bit user code descriptor */
380 #define	LUDATA_SEL	16	/* User data descriptor */
381 #define	LUCODE_SEL	24	/* User code descriptor */
382 #define	LSOL26CALLS_SEL	32	/* Solaris 2.6 system call gate */
383 #define LUDATA32_SEL	56	/* 32 bit user data descriptor (needed?)*/
384 #define	LBSDICALLS_SEL	128	/* BSDI system call gate */
385 
386 #define LDT_SIZE	144
387 
388 #define LSYSRETBASE_SEL	LUCODE32_SEL
389 
390 /*
391  * Checks for valid user selectors. If USER_LDT ever gets implemented
392  * for amd64, these must check the ldt length and SEL_UPL if a user
393  * ldt is active.
394  */
395 #define VALID_USER_DSEL32(s) \
396     (((s) & 0xffff) == GSEL(GUDATA32_SEL, SEL_UPL) || \
397      ((s) & 0xffff) == LSEL(LUDATA32_SEL, SEL_UPL))
398 #define VALID_USER_CSEL32(s) \
399     ((s) == GSEL(GUCODE32_SEL, SEL_UPL) || (s) == LSEL(LUCODE32_SEL, SEL_UPL))
400 
401 #define VALID_USER_CSEL(s) \
402     ((s) == GSEL(GUCODE_SEL, SEL_UPL) || (s) == LSEL(LUCODE_SEL, SEL_UPL))
403 #define VALID_USER_DSEL(s) \
404     ((s) == GSEL(GUDATA_SEL, SEL_UPL) || (s) == LSEL(LUDATA_SEL, SEL_UPL))
405 
406 #else	/*	__x86_64__	*/
407 
408 #include <i386/segments.h>
409 
410 #endif	/*	__x86_64__	*/
411 
412 #endif /* _AMD64_SEGMENTS_H_ */
413