1 /* $NetBSD: segments.h,v 1.59 2017/02/08 09:39:32 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 * 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 (both 8 bytes). 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 (8 bytes). 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 /* 162 * Xen-specific? 163 */ 164 struct ldt_descriptor { 165 __vaddr_t ld_base; 166 uint32_t ld_entries; 167 } __packed; 168 169 /* 170 * Generic descriptor (8 bytes). 171 */ 172 union descriptor { 173 struct segment_descriptor sd; 174 struct gate_descriptor gd; 175 struct ldt_descriptor ld; 176 uint32_t raw[2]; 177 uint64_t raw64; 178 } __packed; 179 180 /* 181 * Region descriptors, used to load gdt/idt tables before segments yet exist. 182 */ 183 struct region_descriptor { 184 unsigned rd_limit:16; /* segment extent */ 185 unsigned rd_base:32; /* base address */ 186 } __packed; 187 188 #if __GNUC__ == 2 && __GNUC_MINOR__ < 7 189 #pragma pack(4) 190 #endif 191 192 #ifdef _KERNEL 193 extern union descriptor *gdtstore, *ldtstore; 194 extern struct gate_descriptor *idt; 195 196 void setgate(struct gate_descriptor *, void *, int, int, int, int); 197 void setregion(struct region_descriptor *, void *, size_t); 198 void setsegment(struct segment_descriptor *, const void *, size_t, int, int, 199 int, int); 200 void unsetgate(struct gate_descriptor *); 201 void cpu_init_idt(void); 202 void update_descriptor(union descriptor *, union descriptor *); 203 204 #if !defined(XEN) 205 void idt_vec_reserve(int); 206 int idt_vec_alloc(int, int); 207 void idt_vec_set(int, void (*)(void)); 208 void idt_vec_free(int); 209 #endif 210 211 #endif /* _KERNEL */ 212 213 #endif /* !_LOCORE */ 214 215 /* system segments and gate types */ 216 #define SDT_SYSNULL 0 /* system null */ 217 #define SDT_SYS286TSS 1 /* system 286 TSS available */ 218 #define SDT_SYSLDT 2 /* system local descriptor table */ 219 #define SDT_SYS286BSY 3 /* system 286 TSS busy */ 220 #define SDT_SYS286CGT 4 /* system 286 call gate */ 221 #define SDT_SYSTASKGT 5 /* system task gate */ 222 #define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 223 #define SDT_SYS286TGT 7 /* system 286 trap gate */ 224 #define SDT_SYSNULL2 8 /* system null again */ 225 #define SDT_SYS386TSS 9 /* system 386 TSS available */ 226 #define SDT_SYSNULL3 10 /* system null again */ 227 #define SDT_SYS386BSY 11 /* system 386 TSS busy */ 228 #define SDT_SYS386CGT 12 /* system 386 call gate */ 229 #define SDT_SYSNULL4 13 /* system null again */ 230 #define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 231 #define SDT_SYS386TGT 15 /* system 386 trap gate */ 232 233 /* memory segment types */ 234 #define SDT_MEMRO 16 /* memory read only */ 235 #define SDT_MEMROA 17 /* memory read only accessed */ 236 #define SDT_MEMRW 18 /* memory read write */ 237 #define SDT_MEMRWA 19 /* memory read write accessed */ 238 #define SDT_MEMROD 20 /* memory read only expand dwn limit */ 239 #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 240 #define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 241 #define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */ 242 #define SDT_MEME 24 /* memory execute only */ 243 #define SDT_MEMEA 25 /* memory execute only accessed */ 244 #define SDT_MEMER 26 /* memory execute read */ 245 #define SDT_MEMERA 27 /* memory execute read accessed */ 246 #define SDT_MEMEC 28 /* memory execute only conforming */ 247 #define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 248 #define SDT_MEMERC 30 /* memory execute read conforming */ 249 #define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 250 251 #define SDTYPE(p) (((const struct segment_descriptor *)(p))->sd_type) 252 /* is memory segment descriptor pointer ? */ 253 #define ISMEMSDP(s) (SDTYPE(s) >= SDT_MEMRO && \ 254 SDTYPE(s) <= SDT_MEMERAC) 255 256 /* is 286 gate descriptor pointer ? */ 257 #define IS286GDP(s) (SDTYPE(s) >= SDT_SYS286CGT && \ 258 SDTYPE(s) < SDT_SYS286TGT) 259 260 /* is 386 gate descriptor pointer ? */ 261 #define IS386GDP(s) (SDTYPE(s) >= SDT_SYS386CGT && \ 262 SDTYPE(s) < SDT_SYS386TGT) 263 264 /* is gate descriptor pointer ? */ 265 #define ISGDP(s) (IS286GDP(s) || IS386GDP(s)) 266 267 /* is segment descriptor pointer ? */ 268 #define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s)) 269 270 /* is system segment descriptor pointer ? */ 271 #define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s)) 272 273 /* 274 * Segment Protection Exception code bits 275 */ 276 #define SEGEX_EXT 0x01 /* recursive or externally induced */ 277 #define SEGEX_IDT 0x02 /* interrupt descriptor table */ 278 #define SEGEX_TI 0x04 /* local descriptor table */ 279 280 /* 281 * Entries in the Interrupt Descriptor Table (IDT) 282 */ 283 #define NIDT 256 284 #define NRSVIDT 32 /* reserved entries for CPU exceptions */ 285 286 /* 287 * Entries in the Global Descriptor Table (GDT). 288 * 289 * NB: If you change GBIOSCODE/GBIOSDATA, you *must* rebuild arch/i386/ 290 * bioscall/biostramp.inc, as that relies on GBIOSCODE/GBIOSDATA and a 291 * normal kernel build does not rebuild it (it's merely included whole- 292 * sale from i386/bioscall.s) 293 * 294 * Also, note that the GEXTBIOSDATA_SEL selector is special, as it maps 295 * to the value 0x0040 (when created as a KPL global selector). Some 296 * BIOSes reference the extended BIOS data area at segment 0040 in a non 297 * relocatable fashion (even when in protected mode); mapping the zero page 298 * via the GEXTBIOSDATA_SEL allows these buggy BIOSes to continue to work 299 * under NetBSD. 300 * 301 * The order if the first 5 descriptors is special; the sysenter/sysexit 302 * instructions depend on them. 303 */ 304 #define GNULL_SEL 0 /* Null descriptor */ 305 #define GCODE_SEL 1 /* Kernel code descriptor */ 306 #define GDATA_SEL 2 /* Kernel data descriptor */ 307 #define GUCODE_SEL 3 /* User code descriptor */ 308 #define GUDATA_SEL 4 /* User data descriptor */ 309 #define GLDT_SEL 5 /* Default LDT descriptor */ 310 #define GCPU_SEL 6 /* per-CPU segment */ 311 #define GEXTBIOSDATA_SEL 8 /* magic to catch BIOS refs to EBDA */ 312 #define GAPM32CODE_SEL 9 /* 3 APM segments must be consecutive */ 313 #define GAPM16CODE_SEL 10 /* and in the specified order: code32 */ 314 #define GAPMDATA_SEL 11 /* code16 and then data per APM spec */ 315 #define GBIOSCODE_SEL 12 316 #define GBIOSDATA_SEL 13 317 #define GPNPBIOSCODE_SEL 14 318 #define GPNPBIOSDATA_SEL 15 319 #define GPNPBIOSSCRATCH_SEL 16 320 #define GPNPBIOSTRAMP_SEL 17 321 #define GTRAPTSS_SEL 18 322 #define GIPITSS_SEL 19 323 #define GUCODEBIG_SEL 20 /* User code with executable stack */ 324 #define GUFS_SEL 21 /* Per-thread %fs */ 325 #define GUGS_SEL 22 /* Per-thread %gs */ 326 #define NGDT 23 327 328 /* 329 * Entries in the Local Descriptor Table (LDT). 330 * DO NOT ADD KERNEL DATA/CODE SEGMENTS TO THIS TABLE. 331 */ 332 #define LSYS5CALLS_SEL 0 /* iBCS system call gate */ 333 #define LSYS5SIGR_SEL 1 /* iBCS sigreturn gate */ 334 #define LUCODE_SEL 2 /* User code descriptor */ 335 #define LUDATA_SEL 3 /* User data descriptor */ 336 #define LSOL26CALLS_SEL 4 /* Solaris 2.6 system call gate */ 337 #define LUCODEBIG_SEL 5 /* User code with executable stack */ 338 #define LBSDICALLS_SEL 16 /* BSDI system call gate */ 339 #define NLDT 17 340 341 #endif /* _I386_SEGMENTS_H_ */ 342