1 /* $NetBSD: segments.h,v 1.44 2007/11/10 20:06:24 ad 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 84 /* 85 * Selectors 86 */ 87 88 #define ISPL(s) ((s) & SEL_RPL) /* what is the priority level of a selector */ 89 #define SEL_KPL 0 /* kernel privilege level */ 90 #define SEL_UPL 3 /* user privilege level */ 91 #define SEL_RPL 3 /* requester's privilege level mask */ 92 #define ISLDT(s) ((s) & SEL_LDT) /* is it local or global */ 93 #define SEL_LDT 4 /* local descriptor table */ 94 #define IDXSEL(s) (((s) >> 3) & 0x1fff) /* index of selector */ 95 #define GSEL(s,r) (((s) << 3) | r) /* a global selector */ 96 #define LSEL(s,r) (((s) << 3) | r | SEL_LDT) /* a local selector */ 97 #define GSYSSEL(s,r) GSEL(s,r) /* compat with amd64 */ 98 99 #if defined(_KERNEL_OPT) 100 #include "opt_vm86.h" 101 #endif 102 103 #ifdef VM86 104 #define USERMODE(c, f) (ISPL(c) == SEL_UPL || ((f) & PSL_VM) != 0) 105 #define KERNELMODE(c, f) (ISPL(c) == SEL_KPL && ((f) & PSL_VM) == 0) 106 #else 107 #define USERMODE(c, f) (ISPL(c) == SEL_UPL) 108 #define KERNELMODE(c, f) (ISPL(c) == SEL_KPL) 109 #endif 110 111 #ifndef _LOCORE 112 113 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7 114 #pragma pack(1) 115 #endif 116 117 /* 118 * Memory and System segment descriptors 119 */ 120 struct segment_descriptor { 121 unsigned sd_lolimit:16; /* segment extent (lsb) */ 122 unsigned sd_lobase:24; /* segment base address (lsb) */ 123 unsigned sd_type:5; /* segment type */ 124 unsigned sd_dpl:2; /* segment descriptor priority level */ 125 unsigned sd_p:1; /* segment descriptor present */ 126 unsigned sd_hilimit:4; /* segment extent (msb) */ 127 unsigned sd_xx:2; /* unused */ 128 unsigned sd_def32:1; /* default 32 vs 16 bit size */ 129 unsigned sd_gran:1; /* limit granularity (byte/page) */ 130 unsigned sd_hibase:8; /* segment base address (msb) */ 131 } __attribute__((packed)); 132 133 /* 134 * Gate descriptors (e.g. indirect descriptors) 135 */ 136 struct gate_descriptor { 137 unsigned gd_looffset:16; /* gate offset (lsb) */ 138 unsigned gd_selector:16; /* gate segment selector */ 139 unsigned gd_stkcpy:5; /* number of stack wds to cpy */ 140 unsigned gd_xx:3; /* unused */ 141 unsigned gd_type:5; /* segment type */ 142 unsigned gd_dpl:2; /* segment descriptor priority level */ 143 unsigned gd_p:1; /* segment descriptor present */ 144 unsigned gd_hioffset:16; /* gate offset (msb) */ 145 } __attribute__((packed)); 146 147 /* 148 * Generic descriptor 149 */ 150 union descriptor { 151 struct segment_descriptor sd; 152 struct gate_descriptor gd; 153 } __attribute__((packed)); 154 155 /* 156 * region descriptors, used to load gdt/idt tables before segments yet exist. 157 */ 158 struct region_descriptor { 159 unsigned rd_limit:16; /* segment extent */ 160 unsigned rd_base:32; /* base address */ 161 } __attribute__((packed)); 162 163 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7 164 #pragma pack(4) 165 #endif 166 167 #ifdef _KERNEL 168 extern union descriptor *gdt, *ldt; 169 extern struct gate_descriptor *idt; 170 171 void setgate(struct gate_descriptor *, void *, int, int, int, int); 172 void setregion(struct region_descriptor *, void *, size_t); 173 void setsegment(struct segment_descriptor *, void *, size_t, int, int, 174 int, int); 175 void setgdt(int, void *, size_t, int, int, int, int); 176 void unsetgate(struct gate_descriptor *); 177 void cpu_init_idt(void); 178 179 int idt_vec_alloc(int, int); 180 void idt_vec_set(int, void (*)(void)); 181 void idt_vec_free(int); 182 183 #endif /* _KERNEL */ 184 185 #endif /* !_LOCORE */ 186 187 /* system segments and gate types */ 188 #define SDT_SYSNULL 0 /* system null */ 189 #define SDT_SYS286TSS 1 /* system 286 TSS available */ 190 #define SDT_SYSLDT 2 /* system local descriptor table */ 191 #define SDT_SYS286BSY 3 /* system 286 TSS busy */ 192 #define SDT_SYS286CGT 4 /* system 286 call gate */ 193 #define SDT_SYSTASKGT 5 /* system task gate */ 194 #define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 195 #define SDT_SYS286TGT 7 /* system 286 trap gate */ 196 #define SDT_SYSNULL2 8 /* system null again */ 197 #define SDT_SYS386TSS 9 /* system 386 TSS available */ 198 #define SDT_SYSNULL3 10 /* system null again */ 199 #define SDT_SYS386BSY 11 /* system 386 TSS busy */ 200 #define SDT_SYS386CGT 12 /* system 386 call gate */ 201 #define SDT_SYSNULL4 13 /* system null again */ 202 #define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 203 #define SDT_SYS386TGT 15 /* system 386 trap gate */ 204 205 /* memory segment types */ 206 #define SDT_MEMRO 16 /* memory read only */ 207 #define SDT_MEMROA 17 /* memory read only accessed */ 208 #define SDT_MEMRW 18 /* memory read write */ 209 #define SDT_MEMRWA 19 /* memory read write accessed */ 210 #define SDT_MEMROD 20 /* memory read only expand dwn limit */ 211 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 212 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 213 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */ 214 #define SDT_MEME 24 /* memory execute only */ 215 #define SDT_MEMEA 25 /* memory execute only accessed */ 216 #define SDT_MEMER 26 /* memory execute read */ 217 #define SDT_MEMERA 27 /* memory execute read accessed */ 218 #define SDT_MEMEC 28 /* memory execute only conforming */ 219 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 220 #define SDT_MEMERC 30 /* memory execute read conforming */ 221 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 222 223 /* is memory segment descriptor pointer ? */ 224 #define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && \ 225 (s->d_type) <= SDT_MEMERAC) 226 227 /* is 286 gate descriptor pointer ? */ 228 #define IS286GDP(s) ((s->d_type) >= SDT_SYS286CGT && \ 229 (s->d_type) < SDT_SYS286TGT) 230 231 /* is 386 gate descriptor pointer ? */ 232 #define IS386GDP(s) ((s->d_type) >= SDT_SYS386CGT && \ 233 (s->d_type) < SDT_SYS386TGT) 234 235 /* is gate descriptor pointer ? */ 236 #define ISGDP(s) (IS286GDP(s) || IS386GDP(s)) 237 238 /* is segment descriptor pointer ? */ 239 #define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s)) 240 241 /* is system segment descriptor pointer ? */ 242 #define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s)) 243 244 /* 245 * Segment Protection Exception code bits 246 */ 247 #define SEGEX_EXT 0x01 /* recursive or externally induced */ 248 #define SEGEX_IDT 0x02 /* interrupt descriptor table */ 249 #define SEGEX_TI 0x04 /* local descriptor table */ 250 251 /* 252 * Entries in the Interrupt Descriptor Table (IDT) 253 */ 254 #define NIDT 256 255 #define NRSVIDT 32 /* reserved entries for CPU exceptions */ 256 257 /* 258 * Entries in the Global Descriptor Table (GDT). 259 * 260 * NB: If you change GBIOSCODE/GBIOSDATA, you *must* rebuild arch/i386/ 261 * bioscall/biostramp.inc, as that relies on GBIOSCODE/GBIOSDATA and a 262 * normal kernel build does not rebuild it (it's merely included whole- 263 * sale from i386/bioscall.s) 264 * 265 * Also, note that the GEXTBIOSDATA_SEL selector is special, as it maps 266 * to the value 0x0040 (when created as a KPL global selector). Some 267 * BIOSes reference the extended BIOS data area at segment 0040 in a non 268 * relocatable fashion (even when in protected mode); mapping the zero page 269 * via the GEXTBIOSDATA_SEL allows these buggy BIOSes to continue to work 270 * under NetBSD. 271 * 272 * The order if the first 5 descriptors is special; the sysenter/sysexit 273 * instructions depend on them. 274 */ 275 #define GNULL_SEL 0 /* Null descriptor */ 276 #define GCODE_SEL 1 /* Kernel code descriptor */ 277 #define GDATA_SEL 2 /* Kernel data descriptor */ 278 #define GUCODE_SEL 3 /* User code descriptor */ 279 #define GUDATA_SEL 4 /* User data descriptor */ 280 #define GLDT_SEL 5 /* Default LDT descriptor */ 281 #define GCPU_SEL 6 /* per-CPU segment */ 282 #define GMACHCALLS_SEL 7 /* Darwin (mach trap) system call gate */ 283 #define GEXTBIOSDATA_SEL 8 /* magic to catch BIOS refs to EBDA */ 284 #define GAPM32CODE_SEL 9 /* 3 APM segments must be consecutive */ 285 #define GAPM16CODE_SEL 10 /* and in the specified order: code32 */ 286 #define GAPMDATA_SEL 11 /* code16 and then data per APM spec */ 287 #define GBIOSCODE_SEL 12 288 #define GBIOSDATA_SEL 13 289 #define GPNPBIOSCODE_SEL 14 290 #define GPNPBIOSDATA_SEL 15 291 #define GPNPBIOSSCRATCH_SEL 16 292 #define GPNPBIOSTRAMP_SEL 17 293 #define GTRAPTSS_SEL 18 294 #define GIPITSS_SEL 19 295 #define GUCODEBIG_SEL 20 /* User code with executable stack */ 296 #define GUFS_SEL 21 297 #define GUGS_SEL 22 298 #define NGDT 23 299 300 /* 301 * Entries in the Local Descriptor Table (LDT) 302 */ 303 #define LSYS5CALLS_SEL 0 /* iBCS system call gate */ 304 #define LSYS5SIGR_SEL 1 /* iBCS sigreturn gate */ 305 #define LUCODE_SEL 2 /* User code descriptor */ 306 #define LUDATA_SEL 3 /* User data descriptor */ 307 #define LSOL26CALLS_SEL 4 /* Solaris 2.6 system call gate */ 308 #define LUCODEBIG_SEL 5 /* User code with executable stack */ 309 #define LBSDICALLS_SEL 16 /* BSDI system call gate */ 310 #define NLDT 17 311 312 #endif /* _I386_SEGMENTS_H_ */ 313