sys/arch/i386/include/segments.h

   1 /*      $NetBSD: segments.h,v 1.54 2011/04/26 15:51:23 joerg 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  * 386 Segmentation Data Structures and definitions
  78  *      William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
  79  */
  80
  81 #ifndef _I386_SEGMENTS_H_
  82 #define _I386_SEGMENTS_H_
  83 #ifdef _KERNEL_OPT
  84 #include "opt_xen.h"
  85 #endif
  86
  87 /*
  88  * Selectors
  89  */
  90
  91 #define ISPL(s)         ((s) & SEL_RPL) /* what is the priority level of a selector */
  92 #ifndef XEN
  93 #define SEL_KPL         0               /* kernel privilege level */
  94 #else
  95 #define SEL_XEN         0               /* Xen privilege level */
  96 #define SEL_KPL         1               /* kernel privilege level */
  97 #endif /* XEN */
  98 #define SEL_UPL         3               /* user privilege level */
  99 #define SEL_RPL         3               /* requester's privilege level mask */
 100 #ifdef XEN
 101 #define CHK_UPL         2               /* user privilege level mask */
 102 #else
 103 #define CHK_UPL         SEL_RPL
 104 #endif /* XEN */
 105 #define ISLDT(s)        ((s) & SEL_LDT) /* is it local or global */
 106 #define SEL_LDT         4               /* local descriptor table */
 107 #define IDXSEL(s)       (((s) >> 3) & 0x1fff)           /* index of selector */
 108 #define IDXSELN(s)      (((s) >> 3))                    /* index of selector */
 109 #define GSEL(s,r)       (((s) << 3) | r)                /* a global selector */
 110 #define LSEL(s,r)       (((s) << 3) | r | SEL_LDT)      /* a local selector */
 111 #define GSYSSEL(s,r)    GSEL(s,r)       /* compat with amd64 */
 112
 113 #if defined(_KERNEL_OPT)
 114 #include "opt_vm86.h"
 115 #endif
 116
 117 #ifdef VM86
 118 #define USERMODE(c, f)          (ISPL(c) == SEL_UPL || ((f) & PSL_VM) != 0)
 119 #define KERNELMODE(c, f)        (ISPL(c) == SEL_KPL && ((f) & PSL_VM) == 0)
 120 #else
 121 #define USERMODE(c, f)          (ISPL(c) == SEL_UPL)
 122 #define KERNELMODE(c, f)        (ISPL(c) == SEL_KPL)
 123 #endif
 124
 125 #ifndef _LOCORE
 126
 127 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 128 #pragma pack(1)
 129 #endif
 130
 131 /*
 132  * Memory and System segment descriptors
 133  */
 134 struct segment_descriptor {
 135         unsigned sd_lolimit:16;         /* segment extent (lsb) */
 136         unsigned sd_lobase:24;          /* segment base address (lsb) */
 137         unsigned sd_type:5;             /* segment type */
 138         unsigned sd_dpl:2;              /* segment descriptor priority level */
 139         unsigned sd_p:1;                /* segment descriptor present */
 140         unsigned sd_hilimit:4;          /* segment extent (msb) */
 141         unsigned sd_xx:2;               /* unused */
 142         unsigned sd_def32:1;            /* default 32 vs 16 bit size */
 143         unsigned sd_gran:1;             /* limit granularity (byte/page) */
 144         unsigned sd_hibase:8;           /* segment base address (msb) */
 145 } __packed;
 146
 147 /*
 148  * Gate descriptors (e.g. indirect descriptors)
 149  */
 150 struct gate_descriptor {
 151         unsigned gd_looffset:16;        /* gate offset (lsb) */
 152         unsigned gd_selector:16;        /* gate segment selector */
 153         unsigned gd_stkcpy:5;           /* number of stack wds to cpy */
 154         unsigned gd_xx:3;               /* unused */
 155         unsigned gd_type:5;             /* segment type */
 156         unsigned gd_dpl:2;              /* segment descriptor priority level */
 157         unsigned gd_p:1;                /* segment descriptor present */
 158         unsigned gd_hioffset:16;        /* gate offset (msb) */
 159 } __packed;
 160
 161 struct ldt_descriptor {
 162         vaddr_t ld_base;
 163         uint32_t ld_entries;
 164 } __packed;
 165
 166 /*
 167  * Generic descriptor
 168  */
 169 union descriptor {
 170         struct segment_descriptor sd;
 171         struct gate_descriptor gd;
 172         struct ldt_descriptor ld;
 173         uint32_t raw[2];
 174         uint64_t raw64;
 175 } __packed;
 176
 177 /*
 178  * region descriptors, used to load gdt/idt tables before segments yet exist.
 179  */
 180 struct region_descriptor {
 181         unsigned rd_limit:16;           /* segment extent */
 182         unsigned rd_base:32;            /* base address  */
 183 } __packed;
 184
 185 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 186 #pragma pack(4)
 187 #endif
 188
 189 #ifdef _KERNEL
 190 extern union descriptor *gdt, *ldt;
 191 extern struct gate_descriptor *idt;
 192
 193 void setgate(struct gate_descriptor *, void *, int, int, int, int);
 194 void setregion(struct region_descriptor *, void *, size_t);
 195 void setsegment(struct segment_descriptor *, const void *, size_t, int, int,
 196     int, int);
 197 void setgdt(int, const void *, size_t, int, int, int, int);
 198 void unsetgate(struct gate_descriptor *);
 199 void cpu_init_idt(void);
 200 void update_descriptor(union descriptor *, union descriptor *);
 201
 202 #if !defined(XEN)
 203 void idt_init(void);
 204 void idt_vec_reserve(int);
 205 int idt_vec_alloc(int, int);
 206 void idt_vec_set(int, void (*)(void));
 207 void idt_vec_free(int);
 208 #endif
 209
 210 #endif /* _KERNEL */
 211
 212 #endif /* !_LOCORE */
 213
 214 /* system segments and gate types */
 215 #define SDT_SYSNULL      0      /* system null */
 216 #define SDT_SYS286TSS    1      /* system 286 TSS available */
 217 #define SDT_SYSLDT       2      /* system local descriptor table */
 218 #define SDT_SYS286BSY    3      /* system 286 TSS busy */
 219 #define SDT_SYS286CGT    4      /* system 286 call gate */
 220 #define SDT_SYSTASKGT    5      /* system task gate */
 221 #define SDT_SYS286IGT    6      /* system 286 interrupt gate */
 222 #define SDT_SYS286TGT    7      /* system 286 trap gate */
 223 #define SDT_SYSNULL2     8      /* system null again */
 224 #define SDT_SYS386TSS    9      /* system 386 TSS available */
 225 #define SDT_SYSNULL3    10      /* system null again */
 226 #define SDT_SYS386BSY   11      /* system 386 TSS busy */
 227 #define SDT_SYS386CGT   12      /* system 386 call gate */
 228 #define SDT_SYSNULL4    13      /* system null again */
 229 #define SDT_SYS386IGT   14      /* system 386 interrupt gate */
 230 #define SDT_SYS386TGT   15      /* system 386 trap gate */
 231
 232 /* memory segment types */
 233 #define SDT_MEMRO       16      /* memory read only */
 234 #define SDT_MEMROA      17      /* memory read only accessed */
 235 #define SDT_MEMRW       18      /* memory read write */
 236 #define SDT_MEMRWA      19      /* memory read write accessed */
 237 #define SDT_MEMROD      20      /* memory read only expand dwn limit */
 238 #define SDT_MEMRODA     21      /* memory read only expand dwn limit accessed */
 239 #define SDT_MEMRWD      22      /* memory read write expand dwn limit */
 240 #define SDT_MEMRWDA     23      /* memory read write expand dwn limit acessed */
 241 #define SDT_MEME        24      /* memory execute only */
 242 #define SDT_MEMEA       25      /* memory execute only accessed */
 243 #define SDT_MEMER       26      /* memory execute read */
 244 #define SDT_MEMERA      27      /* memory execute read accessed */
 245 #define SDT_MEMEC       28      /* memory execute only conforming */
 246 #define SDT_MEMEAC      29      /* memory execute only accessed conforming */
 247 #define SDT_MEMERC      30      /* memory execute read conforming */
 248 #define SDT_MEMERAC     31      /* memory execute read accessed conforming */
 249
 250 #define SDTYPE(p)       (((const struct segment_descriptor *)(p))->sd_type)
 251 /* is memory segment descriptor pointer ? */
 252 #define ISMEMSDP(s)     (SDTYPE(s) >= SDT_MEMRO && \
 253                          SDTYPE(s) <= SDT_MEMERAC)
 254
 255 /* is 286 gate descriptor pointer ? */
 256 #define IS286GDP(s)     (SDTYPE(s) >= SDT_SYS286CGT && \
 257                          SDTYPE(s) < SDT_SYS286TGT)
 258
 259 /* is 386 gate descriptor pointer ? */
 260 #define IS386GDP(s)     (SDTYPE(s) >= SDT_SYS386CGT && \
 261                          SDTYPE(s) < SDT_SYS386TGT)
 262
 263 /* is gate descriptor pointer ? */
 264 #define ISGDP(s)        (IS286GDP(s) || IS386GDP(s))
 265
 266 /* is segment descriptor pointer ? */
 267 #define ISSDP(s)        (ISMEMSDP(s) || !ISGDP(s))
 268
 269 /* is system segment descriptor pointer ? */
 270 #define ISSYSSDP(s)     (!ISMEMSDP(s) && !ISGDP(s))
 271
 272 /*
 273  * Segment Protection Exception code bits
 274  */
 275 #define SEGEX_EXT       0x01    /* recursive or externally induced */
 276 #define SEGEX_IDT       0x02    /* interrupt descriptor table */
 277 #define SEGEX_TI        0x04    /* local descriptor table */
 278
 279 /*
 280  * Entries in the Interrupt Descriptor Table (IDT)
 281  */
 282 #define NIDT    256
 283 #define NRSVIDT 32              /* reserved entries for CPU exceptions */
 284
 285 /*
 286  * Entries in the Global Descriptor Table (GDT).
 287  *
 288  * NB: If you change GBIOSCODE/GBIOSDATA, you *must* rebuild arch/i386/
 289  * bioscall/biostramp.inc, as that relies on GBIOSCODE/GBIOSDATA and a
 290  * normal kernel build does not rebuild it (it's merely included whole-
 291  * sale from i386/bioscall.s)
 292  *
 293  * Also, note that the GEXTBIOSDATA_SEL selector is special, as it maps
 294  * to the value 0x0040 (when created as a KPL global selector).  Some
 295  * BIOSes reference the extended BIOS data area at segment 0040 in a non
 296  * relocatable fashion (even when in protected mode); mapping the zero page
 297  * via the GEXTBIOSDATA_SEL allows these buggy BIOSes to continue to work
 298  * under NetBSD.
 299  *
 300  * The order if the first 5 descriptors is special; the sysenter/sysexit
 301  * instructions depend on them.
 302  */
 303 #define GNULL_SEL       0       /* Null descriptor */
 304 #define GCODE_SEL       1       /* Kernel code descriptor */
 305 #define GDATA_SEL       2       /* Kernel data descriptor */
 306 #define GUCODE_SEL      3       /* User code descriptor */
 307 #define GUDATA_SEL      4       /* User data descriptor */
 308 #define GLDT_SEL        5       /* Default LDT descriptor */
 309 #define GCPU_SEL        6       /* per-CPU segment */
 310 #define GEXTBIOSDATA_SEL 8      /* magic to catch BIOS refs to EBDA */
 311 #define GAPM32CODE_SEL  9       /* 3 APM segments must be consecutive */
 312 #define GAPM16CODE_SEL  10      /* and in the specified order: code32 */
 313 #define GAPMDATA_SEL    11      /* code16 and then data per APM spec */
 314 #define GBIOSCODE_SEL   12
 315 #define GBIOSDATA_SEL   13
 316 #define GPNPBIOSCODE_SEL 14
 317 #define GPNPBIOSDATA_SEL 15
 318 #define GPNPBIOSSCRATCH_SEL 16
 319 #define GPNPBIOSTRAMP_SEL 17
 320 #define GTRAPTSS_SEL    18
 321 #define GIPITSS_SEL     19
 322 #define GUCODEBIG_SEL   20      /* User code with executable stack */
 323 #define GUFS_SEL        21      /* Per-thread %fs */
 324 #define GUGS_SEL        22      /* Per-thread %gs */
 325 #define NGDT            23
 326
 327 /*
 328  * Entries in the Local Descriptor Table (LDT).
 329  * DO NOT ADD KERNEL DATA/CODE SEGMENTS TO THIS TABLE.
 330  */
 331 #define LSYS5CALLS_SEL  0       /* iBCS system call gate */
 332 #define LSYS5SIGR_SEL   1       /* iBCS sigreturn gate */
 333 #define LUCODE_SEL      2       /* User code descriptor */
 334 #define LUDATA_SEL      3       /* User data descriptor */
 335 #define LSOL26CALLS_SEL 4       /* Solaris 2.6 system call gate */
 336 #define LUCODEBIG_SEL   5       /* User code with executable stack */
 337 #define LBSDICALLS_SEL  16      /* BSDI system call gate */
 338 #define NLDT            17
 339
 340 #endif /* _I386_SEGMENTS_H_ */