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segments.h revision 1.26
      1 /*	$NetBSD: segments.h,v 1.26 2016/08/27 14:12:58 maxv 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 (at) wasabisystems.com.
     78  */
     79 
     80 /*
     81  * 386 Segmentation Data Structures and definitions
     82  *	William F. Jolitz (william (at) 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 	uint64_t sd_lolimit:16;	/* segment extent (lsb) */
    154 	uint64_t sd_lobase:24;	/* segment base address (lsb) */
    155 	uint64_t sd_type:5;	/* segment type */
    156 	uint64_t sd_dpl:2;	/* segment descriptor priority level */
    157 	uint64_t sd_p:1;	/* segment descriptor present */
    158 	uint64_t sd_hilimit:4;	/* segment extent (msb) */
    159 	uint64_t sd_xx1:3;	/* avl, long and def32 (not used) */
    160 	uint64_t sd_gran:1;	/* limit granularity (byte/page) */
    161 	uint64_t sd_hibase:40;	/* segment base address (msb) */
    162 	uint64_t sd_xx2:8;	/* reserved */
    163 	uint64_t sd_zero:5;	/* must be zero */
    164 	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 	uint64_t gd_looffset:16;/* gate offset (lsb) */
    199 	uint64_t gd_selector:16;/* gate segment selector */
    200 	uint64_t gd_ist:3;	/* IST select */
    201 	uint64_t gd_xx1:5;	/* reserved */
    202 	uint64_t gd_type:5;	/* segment type */
    203 	uint64_t gd_dpl:2;	/* segment descriptor priority level */
    204 	uint64_t gd_p:1;	/* segment descriptor present */
    205 	uint64_t gd_hioffset:48;/* gate offset (msb) */
    206 	uint64_t gd_xx2:8;	/* reserved */
    207 	uint64_t gd_zero:5;	/* must be zero */
    208 	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 void cpu_fsgs_zero(struct lwp *);
    260 void cpu_fsgs_reload(struct lwp *, int, int);
    261 
    262 #endif /* _KERNEL */
    263 
    264 #endif /* !_LOCORE */
    265 
    266 /* system segments and gate types */
    267 #define SDT_SYSNULL	 0	/* system null */
    268 #define SDT_SYS286TSS	 1	/* system 286 TSS available */
    269 #define SDT_SYSLDT	 2	/* system local descriptor table */
    270 #define SDT_SYS286BSY	 3	/* system 286 TSS busy */
    271 #define SDT_SYS286CGT	 4	/* system 286 call gate */
    272 #define SDT_SYSTASKGT	 5	/* system task gate */
    273 #define SDT_SYS286IGT	 6	/* system 286 interrupt gate */
    274 #define SDT_SYS286TGT	 7	/* system 286 trap gate */
    275 #define SDT_SYSNULL2	 8	/* system null again */
    276 #define SDT_SYS386TSS	 9	/* system 386 TSS available */
    277 #define SDT_SYSNULL3	10	/* system null again */
    278 #define SDT_SYS386BSY	11	/* system 386 TSS busy */
    279 #define SDT_SYS386CGT	12	/* system 386 call gate */
    280 #define SDT_SYSNULL4	13	/* system null again */
    281 #define SDT_SYS386IGT	14	/* system 386 interrupt gate */
    282 #define SDT_SYS386TGT	15	/* system 386 trap gate */
    283 
    284 /* memory segment types */
    285 #define SDT_MEMRO	16	/* memory read only */
    286 #define SDT_MEMROA	17	/* memory read only accessed */
    287 #define SDT_MEMRW	18	/* memory read write */
    288 #define SDT_MEMRWA	19	/* memory read write accessed */
    289 #define SDT_MEMROD	20	/* memory read only expand dwn limit */
    290 #define SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
    291 #define SDT_MEMRWD	22	/* memory read write expand dwn limit */
    292 #define SDT_MEMRWDA	23	/* memory read write expand dwn limit accessed */
    293 #define SDT_MEME	24	/* memory execute only */
    294 #define SDT_MEMEA	25	/* memory execute only accessed */
    295 #define SDT_MEMER	26	/* memory execute read */
    296 #define SDT_MEMERA	27	/* memory execute read accessed */
    297 #define SDT_MEMEC	28	/* memory execute only conforming */
    298 #define SDT_MEMEAC	29	/* memory execute only accessed conforming */
    299 #define SDT_MEMERC	30	/* memory execute read conforming */
    300 #define SDT_MEMERAC	31	/* memory execute read accessed conforming */
    301 
    302 /* is memory segment descriptor pointer ? */
    303 #define ISMEMSDP(s)	((s->d_type) >= SDT_MEMRO && \
    304 			 (s->d_type) <= SDT_MEMERAC)
    305 
    306 /* is 286 gate descriptor pointer ? */
    307 #define IS286GDP(s)	((s->d_type) >= SDT_SYS286CGT && \
    308 			 (s->d_type) < SDT_SYS286TGT)
    309 
    310 /* is 386 gate descriptor pointer ? */
    311 #define IS386GDP(s)	((s->d_type) >= SDT_SYS386CGT && \
    312 			 (s->d_type) < SDT_SYS386TGT)
    313 
    314 /* is gate descriptor pointer ? */
    315 #define ISGDP(s)	(IS286GDP(s) || IS386GDP(s))
    316 
    317 /* is segment descriptor pointer ? */
    318 #define ISSDP(s)	(ISMEMSDP(s) || !ISGDP(s))
    319 
    320 /* is system segment descriptor pointer ? */
    321 #define ISSYSSDP(s)	(!ISMEMSDP(s) && !ISGDP(s))
    322 
    323 /*
    324  * Segment Protection Exception code bits
    325  */
    326 #define SEGEX_EXT	0x01	/* recursive or externally induced */
    327 #define SEGEX_IDT	0x02	/* interrupt descriptor table */
    328 #define SEGEX_TI	0x04	/* local descriptor table */
    329 
    330 /*
    331  * Entries in the Interrupt Descriptor Table (IDT)
    332  */
    333 #define NIDT	256
    334 #define NCPUIDT	32		/* reserved entries for CPU exceptions */
    335 
    336 /*
    337  * Entries in the Global Descriptor Table (GDT)
    338  * The code and data descriptors must come first. There
    339  * are NGDT_MEM of them.
    340  *
    341  * Then come the predefined LDT (and possibly TSS) descriptors.
    342  * There are NGDT_SYS of them.
    343  */
    344 #define GNULL_SEL	0	/* Null descriptor */
    345 #define GCODE_SEL	1	/* Kernel code descriptor */
    346 #define GDATA_SEL	2	/* Kernel data descriptor */
    347 #define GUCODE_SEL	3	/* User code descriptor */
    348 #define GUDATA_SEL	4	/* User data descriptor */
    349 #define GAPM32CODE_SEL	5
    350 #define GAPM16CODE_SEL	6
    351 #define GAPMDATA_SEL	7
    352 #define GBIOSCODE_SEL	8
    353 #define GBIOSDATA_SEL	9
    354 #define GPNPBIOSCODE_SEL 10
    355 #define GPNPBIOSDATA_SEL 11
    356 #define GPNPBIOSSCRATCH_SEL 12
    357 #define GPNPBIOSTRAMP_SEL 13
    358 #define GUCODE32_SEL	14
    359 #define GUDATA32_SEL	15
    360 #define GUFS_SEL	16	/* 32-bit Per-thread %fs */
    361 #define GUGS_SEL	17	/* 32-bit Per-thread %gs */
    362 #define NGDT_MEM	18
    363 
    364 #define GLDT_SEL	0	/* Default LDT descriptor */
    365 #define NGDT_SYS	1
    366 
    367 #define GDT_ADDR_MEM(s,i)	\
    368     ((struct mem_segment_descriptor *)((s) + ((i) << 3)))
    369 #define GDT_ADDR_SYS(s,i)	\
    370    ((struct sys_segment_descriptor *)((s) + (((i) << 4) + SYSSEL_START)))
    371 
    372 /*
    373  * Byte offsets in the Local Descriptor Table (LDT)
    374  * Strange order because of syscall/sysret insns
    375  */
    376 #define LSYS5CALLS_SEL	0	/* iBCS system call gate */
    377 /*			8	   second half */
    378 #define LSOL26CALLS_SEL	32	/* Solaris 2.6 system call gate */
    379 /*			40	   second half */
    380 #define LUCODE32_SEL	48	/* 32 bit user code descriptor */
    381 #define LUDATA_SEL	56	/* User data descriptor */
    382 #define LUCODE_SEL	64	/* User code descriptor */
    383 #define LUDATA32_SEL	72	/* 32 bit user data descriptor (needed?)*/
    384 #define LBSDICALLS_SEL	128	/* BSDI system call gate */
    385 /*			136	   second half */
    386 
    387 #define LDT_SIZE	144
    388 
    389 #define LSYSRETBASE_SEL	LUCODE32_SEL
    390 
    391 /*
    392  * Checks for valid user selectors. If USER_LDT ever gets implemented
    393  * for amd64, these must check the ldt length and SEL_UPL if a user
    394  * ldt is active.
    395  */
    396 #define VALID_USER_DSEL32(s) \
    397     (((s) & 0xffff) == GSEL(GUDATA32_SEL, SEL_UPL) || \
    398      ((s) & 0xffff) == LSEL(LUDATA32_SEL, SEL_UPL))
    399 #define VALID_USER_CSEL32(s) \
    400     ((s) == GSEL(GUCODE32_SEL, SEL_UPL) || (s) == LSEL(LUCODE32_SEL, SEL_UPL))
    401 #define VALID_USER_FSEL32(s) \
    402     (((s) & 0xffff) == GSEL(GUFS_SEL, SEL_UPL))
    403 #define VALID_USER_GSEL32(s) \
    404     (((s) & 0xffff) == GSEL(GUGS_SEL, SEL_UPL))
    405 
    406 #define VALID_USER_CSEL(s) \
    407     ((s) == GSEL(GUCODE_SEL, SEL_UPL) || (s) == LSEL(LUCODE_SEL, SEL_UPL))
    408 #define VALID_USER_DSEL(s) \
    409     ((s) == GSEL(GUDATA_SEL, SEL_UPL) || (s) == LSEL(LUDATA_SEL, SEL_UPL))
    410 
    411 #else	/*	__x86_64__	*/
    412 
    413 #include <i386/segments.h>
    414 
    415 #endif	/*	__x86_64__	*/
    416 
    417 #endif /* _AMD64_SEGMENTS_H_ */
    418