1/* $OpenBSD: segments.h,v 1.17 2024/02/25 22:33:09 guenther Exp $ */ 2/* $NetBSD: segments.h,v 1.1 2003/04/26 18:39:47 fvdl Exp $ */ 3 4/*- 5 * Copyright (c) 1995, 1997 6 * Charles M. Hannum. All rights reserved. 7 * Copyright (c) 1989, 1990 William F. Jolitz 8 * Copyright (c) 1990 The Regents of the University of California. 9 * All rights reserved. 10 * 11 * This code is derived from software contributed to Berkeley by 12 * William Jolitz. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)segments.h 7.1 (Berkeley) 5/9/91 39 */ 40 41/* 42 * Adapted for NetBSD/amd64 by fvdl@wasabisystems.com. 43 */ 44 45/* 46 * 386 Segmentation Data Structures and definitions 47 * William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989 48 */ 49 50#ifndef _MACHINE_SEGMENTS_H_ 51#define _MACHINE_SEGMENTS_H_ 52 53/* 54 * Selectors 55 */ 56 57#define ISPL(s) ((s) & SEL_RPL) /* what is the priority level of a selector */ 58#define SEL_KPL 0 /* kernel privilege level */ 59#define SEL_UPL 3 /* user privilege level */ 60#define SEL_RPL 3 /* requester's privilege level mask */ 61#define ISLDT(s) ((s) & SEL_LDT) /* is it local or global */ 62#define SEL_LDT 4 /* local descriptor table */ 63 64#define SYSSEL_START (NGDT_MEM << 3) 65#define GDT_SIZE (SYSSEL_START + (NGDT_SYS << 4)) 66 67/* 68 * These define the index not from the start of the GDT, but from 69 * the part of the GDT that they're allocated from. 70 * First NGDT_MEM entries are 8-byte descriptors for CS and DS. 71 * Next NGDT_SYS entries are 16-byte descriptors defining TSSs. 72 */ 73 74#define IDXSEL(s) (((s) >> 3) & 0x1fff) 75#define IDXDYNSEL(s) ((((s) & ~SEL_RPL) - DYNSEL_START) >> 4) 76 77#define GSEL(s,r) (((s) << 3) | r) 78#define GSYSSEL(s,r) ((((s) << 4) + SYSSEL_START) | r) 79#define GDYNSEL(s,r) ((((s) << 4) + DYNSEL_START) | r | SEL_KPL) 80 81#define LSEL(s,r) ((s) | r | SEL_LDT) 82 83#define USERMODE(c, f) (ISPL(c) == SEL_UPL) 84#define KERNELMODE(c, f) (ISPL(c) == SEL_KPL) 85 86#ifndef _LOCORE 87 88/* 89 * Memory and System segment descriptors 90 */ 91 92/* 93 * Below is used for TSS and LDT. 94 */ 95struct sys_segment_descriptor { 96 u_int64_t sd_lolimit:16; /* segment extent (lsb) */ 97 u_int64_t sd_lobase:24; /* segment base address (lsb) */ 98 u_int64_t sd_type:5; /* segment type */ 99 u_int64_t sd_dpl:2; /* segment descriptor priority level */ 100 u_int64_t sd_p:1; /* segment descriptor present */ 101 u_int64_t sd_hilimit:4; /* segment extent (msb) */ 102 u_int64_t sd_xx1:3; /* avl, long and def32 (not used) */ 103 u_int64_t sd_gran:1; /* limit granularity (byte/page) */ 104 u_int64_t sd_hibase:40; /* segment base address (msb) */ 105 u_int64_t sd_xx2:8; /* reserved */ 106 u_int64_t sd_zero:5; /* must be zero */ 107 u_int64_t sd_xx3:19; /* reserved */ 108} __packed; 109 110/* 111 * Below is used for cs, ds, etc. 112 */ 113struct mem_segment_descriptor { 114 unsigned int sd_lolimit:16; /* segment extent (lsb) */ 115 unsigned int sd_lobase:24; /* segment base address (lsb) */ 116 unsigned int sd_type:5; /* segment type */ 117 unsigned int sd_dpl:2; /* segment descriptor priority level */ 118 unsigned int sd_p:1; /* segment descriptor present */ 119 unsigned int sd_hilimit:4; /* segment extent (msb) */ 120 unsigned int sd_avl:1; /* available */ 121 unsigned int sd_long:1; /* long mode */ 122 unsigned int sd_def32:1; /* default 32 vs 16 bit size */ 123 unsigned int sd_gran:1; /* limit granularity (byte/page) */ 124 unsigned int sd_hibase:8; /* segment base address (msb) */ 125} __packed; 126 127/* 128 * Gate descriptors (e.g. indirect descriptors) 129 */ 130struct gate_descriptor { 131 u_int64_t gd_looffset:16; /* gate offset (lsb) */ 132 u_int64_t gd_selector:16; /* gate segment selector */ 133 u_int64_t gd_ist:3; /* IST select */ 134 u_int64_t gd_xx1:5; /* reserved */ 135 u_int64_t gd_type:5; /* segment type */ 136 u_int64_t gd_dpl:2; /* segment descriptor priority level */ 137 u_int64_t gd_p:1; /* segment descriptor present */ 138 u_int64_t gd_hioffset:48; /* gate offset (msb) */ 139 u_int64_t gd_xx2:8; /* reserved */ 140 u_int64_t gd_zero:5; /* must be zero */ 141 u_int64_t gd_xx3:19; /* reserved */ 142} __packed; 143 144/* 145 * region descriptors, used to load gdt/idt tables before segments yet exist. 146 */ 147struct region_descriptor { 148 u_int16_t rd_limit; /* segment extent */ 149 u_int64_t rd_base; /* base address */ 150} __packed; 151 152#ifdef _KERNEL 153extern struct gate_descriptor *idt; 154 155void setgate(struct gate_descriptor *, void *, int, int, int, int); 156void unsetgate(struct gate_descriptor *); 157void setregion(struct region_descriptor *, void *, u_int16_t); 158void set_sys_segment(struct sys_segment_descriptor *, void *, size_t, 159 int, int, int); 160void set_mem_segment(struct mem_segment_descriptor *, void *, size_t, 161 int, int, int, int, int); 162int idt_vec_alloc(int, int); 163int idt_vec_alloc_range(int, int, int); 164void idt_vec_set(int, void (*)(void)); 165void idt_vec_free(int); 166void cpu_init_idt(void); 167 168#endif /* _KERNEL */ 169 170#endif /* !_LOCORE */ 171 172/* system segments and gate types */ 173#define SDT_SYSNULL 0 /* system null */ 174#define SDT_SYS286TSS 1 /* system 286 TSS available */ 175#define SDT_SYSLDT 2 /* system local descriptor table */ 176#define SDT_SYS286BSY 3 /* system 286 TSS busy */ 177#define SDT_SYS286CGT 4 /* system 286 call gate */ 178#define SDT_SYSTASKGT 5 /* system task gate */ 179#define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 180#define SDT_SYS286TGT 7 /* system 286 trap gate */ 181#define SDT_SYSNULL2 8 /* system null again */ 182#define SDT_SYS386TSS 9 /* system 386 TSS available */ 183#define SDT_SYSNULL3 10 /* system null again */ 184#define SDT_SYS386BSY 11 /* system 386 TSS busy */ 185#define SDT_SYS386CGT 12 /* system 386 call gate */ 186#define SDT_SYSNULL4 13 /* system null again */ 187#define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 188#define SDT_SYS386TGT 15 /* system 386 trap gate */ 189 190/* memory segment types */ 191#define SDT_MEMRO 16 /* memory read only */ 192#define SDT_MEMROA 17 /* memory read only accessed */ 193#define SDT_MEMRW 18 /* memory read write */ 194#define SDT_MEMRWA 19 /* memory read write accessed */ 195#define SDT_MEMROD 20 /* memory read only expand dwn limit */ 196#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 197#define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 198#define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */ 199#define SDT_MEME 24 /* memory execute only */ 200#define SDT_MEMEA 25 /* memory execute only accessed */ 201#define SDT_MEMER 26 /* memory execute read */ 202#define SDT_MEMERA 27 /* memory execute read accessed */ 203#define SDT_MEMEC 28 /* memory execute only conforming */ 204#define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 205#define SDT_MEMERC 30 /* memory execute read conforming */ 206#define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 207 208/* is memory segment descriptor pointer ? */ 209#define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && \ 210 (s->d_type) <= SDT_MEMERAC) 211 212/* is 286 gate descriptor pointer ? */ 213#define IS286GDP(s) ((s->d_type) >= SDT_SYS286CGT && \ 214 (s->d_type) < SDT_SYS286TGT) 215 216/* is 386 gate descriptor pointer ? */ 217#define IS386GDP(s) ((s->d_type) >= SDT_SYS386CGT && \ 218 (s->d_type) < SDT_SYS386TGT) 219 220/* is gate descriptor pointer ? */ 221#define ISGDP(s) (IS286GDP(s) || IS386GDP(s)) 222 223/* is segment descriptor pointer ? */ 224#define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s)) 225 226/* is system segment descriptor pointer ? */ 227#define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s)) 228 229/* 230 * Segment Protection Exception code bits 231 */ 232#define SEGEX_EXT 0x01 /* recursive or externally induced */ 233#define SEGEX_IDT 0x02 /* interrupt descriptor table */ 234#define SEGEX_TI 0x04 /* local descriptor table */ 235 236/* 237 * Entries in the Interrupt Descriptor Table (IDT) 238 */ 239#define NIDT 256 240#define NRSVIDT 32 /* reserved entries for cpu exceptions */ 241 242/* 243 * Entries in the Global Descriptor Table (GDT) 244 * The code and data descriptors must come first. There 245 * are NGDT_MEM of them. 246 * 247 * Then comes the predefined TSS descriptor. 248 * There are NGDT_SYS of them. 249 * 250 * The particular order of the UDATA and UCODE descriptors is 251 * required by the sysretq instruction. 252 */ 253#define GNULL_SEL 0 /* Null descriptor */ 254#define GCODE_SEL 1 /* Kernel code descriptor */ 255#define GDATA_SEL 2 /* Kernel data descriptor */ 256#define GUDATA_SEL 3 /* User data descriptor */ 257#define GUCODE_SEL 4 /* User code descriptor */ 258#define NGDT_MEM 5 259 260#define GPROC0_SEL 0 /* common TSS */ 261#define NGDT_SYS 1 262 263#define GDT_SYS_OFFSET (NGDT_MEM << 3) 264 265#define GDT_ADDR_MEM(s,i) \ 266 ((struct mem_segment_descriptor *)((char *)(s) + ((i) << 3))) 267#define GDT_ADDR_SYS(s,i) \ 268 ((struct sys_segment_descriptor *)((char *)(s) + ((i) << 4) + SYSSEL_START)) 269 270/* 271 * Checks for valid user selectors. 272 */ 273#define VALID_USER_CSEL(s) \ 274 ((s) == GSEL(GUCODE_SEL, SEL_UPL)) 275#define VALID_USER_DSEL(s) \ 276 ((s) == GSEL(GUDATA_SEL, SEL_UPL)) 277 278#endif /* _MACHINE_SEGMENTS_H_ */ 279