1 /* $NetBSD: segments.h,v 1.70 2022/05/18 13:56:32 andvar 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 XENPV 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 /* XENPV */ 98 #define SEL_UPL 3 /* user privilege level */ 99 #define SEL_RPL 3 /* requester's privilege level mask */ 100 #ifdef XENPV 101 #define CHK_UPL 2 /* user privilege level mask */ 102 #else 103 #define CHK_UPL SEL_RPL 104 #endif /* XENPV */ 105 #define ISLDT(s) ((s) & SEL_LDT) /* is it local or global */ 106 #define SEL_LDT 4 /* local descriptor table */ 107 108 #define IOPL_KPL SEL_KPL 109 110 /* Dynamically allocated TSSs and LDTs start (byte offset) */ 111 #define DYNSEL_START (NGDT << 3) 112 113 #define IDXSEL(s) (((s) >> 3) & 0x1fff) /* index of selector */ 114 #define IDXSELN(s) (((s) >> 3)) /* index of selector */ 115 #define IDXDYNSEL(s) ((((s) & ~SEL_RPL) - DYNSEL_START) >> 3) 116 117 #define GSEL(s,r) (((s) << 3) | r) /* a global selector */ 118 #define GSYSSEL(s,r) GSEL(s,r) /* compat with amd64 */ 119 #define GDYNSEL(s,r) ((((s) << 3) + DYNSEL_START) | r | SEL_KPL) 120 121 #define LSEL(s,r) (((s) << 3) | r | SEL_LDT) /* a local selector */ 122 123 #define USERMODE(c) (ISPL(c) == SEL_UPL) 124 #define KERNELMODE(c) (ISPL(c) == SEL_KPL) 125 126 #ifndef _LOCORE 127 128 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7 129 #pragma pack(1) 130 #endif 131 132 /* 133 * Memory and System segment descriptors (both 8 bytes). 134 */ 135 struct segment_descriptor { 136 unsigned sd_lolimit:16; /* segment extent (lsb) */ 137 unsigned sd_lobase:24; /* segment base address (lsb) */ 138 unsigned sd_type:5; /* segment type */ 139 unsigned sd_dpl:2; /* segment descriptor priority level */ 140 unsigned sd_p:1; /* segment descriptor present */ 141 unsigned sd_hilimit:4; /* segment extent (msb) */ 142 unsigned sd_xx:2; /* unused */ 143 unsigned sd_def32:1; /* default 32 vs 16 bit size */ 144 unsigned sd_gran:1; /* limit granularity (byte/page) */ 145 unsigned sd_hibase:8; /* segment base address (msb) */ 146 } __packed; 147 148 /* 149 * Gate descriptors (8 bytes). 150 */ 151 struct gate_descriptor { 152 unsigned gd_looffset:16; /* gate offset (lsb) */ 153 unsigned gd_selector:16; /* gate segment selector */ 154 unsigned gd_stkcpy:5; /* number of stack wds to cpy */ 155 unsigned gd_xx:3; /* unused */ 156 unsigned gd_type:5; /* segment type */ 157 unsigned gd_dpl:2; /* segment descriptor priority level */ 158 unsigned gd_p:1; /* segment descriptor present */ 159 unsigned gd_hioffset:16; /* gate offset (msb) */ 160 } __packed; 161 162 /* 163 * Xen-specific? 164 */ 165 struct ldt_descriptor { 166 __vaddr_t ld_base; 167 uint32_t ld_entries; 168 } __packed; 169 170 /* 171 * Generic descriptor (8 bytes). 172 */ 173 union descriptor { 174 struct segment_descriptor sd; 175 struct gate_descriptor gd; 176 struct ldt_descriptor ld; 177 uint32_t raw[2]; 178 uint64_t raw64; 179 } __packed; 180 181 /* 182 * Region descriptors, used to load gdt/idt tables before segments yet exist. 183 */ 184 struct region_descriptor { 185 unsigned rd_limit:16; /* segment extent */ 186 unsigned rd_base:32; /* base address */ 187 } __packed; 188 189 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7 190 #pragma pack(4) 191 #endif 192 193 #ifdef _KERNEL 194 #ifdef XENPV 195 typedef struct trap_info idt_descriptor_t; 196 #else 197 typedef struct gate_descriptor idt_descriptor_t; 198 #endif /* XENPV */ 199 extern union descriptor *gdtstore, *ldtstore; 200 201 void setgate(struct gate_descriptor *, void *, int, int, int, int); 202 void set_idtgate(idt_descriptor_t *, void *, int, int, int, int); 203 void unset_idtgate(idt_descriptor_t *); 204 void setregion(struct region_descriptor *, void *, size_t); 205 void setsegment(struct segment_descriptor *, const void *, size_t, int, int, 206 int, int); 207 void unsetgate(struct gate_descriptor *); 208 void update_descriptor(union descriptor *, union descriptor *); 209 210 struct idt_vec; 211 void idt_vec_reserve(struct idt_vec *, int); 212 int idt_vec_alloc(struct idt_vec *, int, int); 213 void idt_vec_set(struct idt_vec *, int, void (*)(void)); 214 void idt_vec_free(struct idt_vec *, int); 215 void idt_vec_init_cpu_md(struct idt_vec *, cpuid_t); 216 bool idt_vec_is_pcpu(void); 217 struct idt_vec* idt_vec_ref(struct idt_vec *); 218 219 220 #endif /* _KERNEL */ 221 222 #endif /* !_LOCORE */ 223 224 /* system segments and gate types */ 225 #define SDT_SYSNULL 0 /* system null */ 226 #define SDT_SYS286TSS 1 /* system 286 TSS available */ 227 #define SDT_SYSLDT 2 /* system local descriptor table */ 228 #define SDT_SYS286BSY 3 /* system 286 TSS busy */ 229 #define SDT_SYS286CGT 4 /* system 286 call gate */ 230 #define SDT_SYSTASKGT 5 /* system task gate */ 231 #define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 232 #define SDT_SYS286TGT 7 /* system 286 trap gate */ 233 #define SDT_SYSNULL2 8 /* system null again */ 234 #define SDT_SYS386TSS 9 /* system 386 TSS available */ 235 #define SDT_SYSNULL3 10 /* system null again */ 236 #define SDT_SYS386BSY 11 /* system 386 TSS busy */ 237 #define SDT_SYS386CGT 12 /* system 386 call gate */ 238 #define SDT_SYSNULL4 13 /* system null again */ 239 #define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 240 #define SDT_SYS386TGT 15 /* system 386 trap gate */ 241 242 /* memory segment types */ 243 #define SDT_MEMRO 16 /* memory read only */ 244 #define SDT_MEMROA 17 /* memory read only accessed */ 245 #define SDT_MEMRW 18 /* memory read write */ 246 #define SDT_MEMRWA 19 /* memory read write accessed */ 247 #define SDT_MEMROD 20 /* memory read only expand dwn limit */ 248 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 249 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 250 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */ 251 #define SDT_MEME 24 /* memory execute only */ 252 #define SDT_MEMEA 25 /* memory execute only accessed */ 253 #define SDT_MEMER 26 /* memory execute read */ 254 #define SDT_MEMERA 27 /* memory execute read accessed */ 255 #define SDT_MEMEC 28 /* memory execute only conforming */ 256 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 257 #define SDT_MEMERC 30 /* memory execute read conforming */ 258 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 259 260 #define SDTYPE(p) (((const struct segment_descriptor *)(p))->sd_type) 261 /* is memory segment descriptor pointer ? */ 262 #define ISMEMSDP(s) (SDTYPE(s) >= SDT_MEMRO && \ 263 SDTYPE(s) <= SDT_MEMERAC) 264 265 /* is 286 gate descriptor pointer ? */ 266 #define IS286GDP(s) (SDTYPE(s) >= SDT_SYS286CGT && \ 267 SDTYPE(s) < SDT_SYS286TGT) 268 269 /* is 386 gate descriptor pointer ? */ 270 #define IS386GDP(s) (SDTYPE(s) >= SDT_SYS386CGT && \ 271 SDTYPE(s) < SDT_SYS386TGT) 272 273 /* is gate descriptor pointer ? */ 274 #define ISGDP(s) (IS286GDP(s) || IS386GDP(s)) 275 276 /* is segment descriptor pointer ? */ 277 #define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s)) 278 279 /* is system segment descriptor pointer ? */ 280 #define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s)) 281 282 /* 283 * Segment Protection Exception code bits 284 */ 285 #define SEGEX_EXT 0x01 /* recursive or externally induced */ 286 #define SEGEX_IDT 0x02 /* interrupt descriptor table */ 287 #define SEGEX_TI 0x04 /* local descriptor table */ 288 289 /* 290 * Entries in the Interrupt Descriptor Table (IDT) 291 */ 292 #define NIDT 256 293 #define NRSVIDT 32 /* reserved entries for CPU exceptions */ 294 295 /* 296 * Entries in the Global Descriptor Table (GDT). 297 * 298 * NB: If you change GBIOSCODE/GBIOSDATA, you *must* rebuild arch/i386/ 299 * bioscall/biostramp.inc, as that relies on GBIOSCODE/GBIOSDATA and a 300 * normal kernel build does not rebuild it (it's merely included whole- 301 * sale from i386/bioscall.s) 302 * 303 * Also, note that the GEXTBIOSDATA_SEL selector is special, as it maps 304 * to the value 0x0040 (when created as a KPL global selector). Some 305 * BIOSes reference the extended BIOS data area at segment 0040 in a non 306 * relocatable fashion (even when in protected mode); mapping the zero page 307 * via the GEXTBIOSDATA_SEL allows these buggy BIOSes to continue to work 308 * under NetBSD. 309 * 310 * The order if the first 5 descriptors is special; the sysenter/sysexit 311 * instructions depend on them. 312 */ 313 #define GNULL_SEL 0 /* Null descriptor */ 314 #define GCODE_SEL 1 /* Kernel code descriptor */ 315 #define GDATA_SEL 2 /* Kernel data descriptor */ 316 #define GUCODE_SEL 3 /* User code descriptor */ 317 #define GUDATA_SEL 4 /* User data descriptor */ 318 #define GLDT_SEL 5 /* Default LDT descriptor */ 319 #define GCPU_SEL 6 /* per-CPU segment */ 320 #define GEXTBIOSDATA_SEL 8 /* magic to catch BIOS refs to EBDA */ 321 #define GAPM32CODE_SEL 9 /* 3 APM segments must be consecutive */ 322 #define GAPM16CODE_SEL 10 /* and in the specified order: code32 */ 323 #define GAPMDATA_SEL 11 /* code16 and then data per APM spec */ 324 #define GBIOSCODE_SEL 12 325 #define GBIOSDATA_SEL 13 326 #define GPNPBIOSCODE_SEL 14 327 #define GPNPBIOSDATA_SEL 15 328 #define GPNPBIOSSCRATCH_SEL 16 329 #define GPNPBIOSTRAMP_SEL 17 330 #define GTRAPTSS_SEL 18 331 #define GIPITSS_SEL 19 332 #define GUCODEBIG_SEL 20 /* User code with executable stack */ 333 #define GUFS_SEL 21 /* Per-thread %fs */ 334 #define GUGS_SEL 22 /* Per-thread %gs */ 335 #define NGDT 23 336 337 /* 338 * Entries in the Local Descriptor Table (LDT). 339 * DO NOT ADD KERNEL DATA/CODE SEGMENTS TO THIS TABLE. 340 */ 341 #define LSYS5CALLS_SEL 0 /* iBCS system call gate */ 342 #define LSYS5SIGR_SEL 1 /* iBCS sigreturn gate */ 343 #define LUCODE_SEL 2 /* User code descriptor */ 344 #define LUDATA_SEL 3 /* User data descriptor */ 345 #define LSOL26CALLS_SEL 4 /* Solaris 2.6 system call gate */ 346 #define LUCODEBIG_SEL 5 /* User code with executable stack */ 347 #define LBSDICALLS_SEL 16 /* BSDI system call gate */ 348 #define NLDT 17 349 350 #endif /* _I386_SEGMENTS_H_ */ 351