segments.h revision 181775
1/*- 2 * Copyright (c) 1989, 1990 William F. Jolitz 3 * Copyright (c) 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)segments.h 7.1 (Berkeley) 5/9/91 34 * $FreeBSD: head/sys/i386/include/segments.h 181775 2008-08-15 20:51:31Z kmacy $ 35 */ 36 37#ifndef _MACHINE_SEGMENTS_H_ 38#define _MACHINE_SEGMENTS_H_ 39 40/* 41 * 386 Segmentation Data Structures and definitions 42 * William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989 43 */ 44 45/* 46 * Selectors 47 */ 48 49#define ISPL(s) ((s)&3) /* what is the priority level of a selector */ 50#ifdef XEN 51#define SEL_KPL 1 /* kernel priority level */ 52#else 53#define SEL_KPL 0 /* kernel priority level */ 54#endif 55#define SEL_UPL 3 /* user priority level */ 56#define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */ 57#define SEL_LDT 4 /* local descriptor table */ 58#define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */ 59#define LSEL(s,r) (((s)<<3) | SEL_LDT | r) /* a local selector */ 60#define GSEL(s,r) (((s)<<3) | r) /* a global selector */ 61 62/* 63 * Memory and System segment descriptors 64 */ 65struct segment_descriptor { 66 unsigned sd_lolimit:16 ; /* segment extent (lsb) */ 67 unsigned sd_lobase:24 __packed; /* segment base address (lsb) */ 68 unsigned sd_type:5 ; /* segment type */ 69 unsigned sd_dpl:2 ; /* segment descriptor priority level */ 70 unsigned sd_p:1 ; /* segment descriptor present */ 71 unsigned sd_hilimit:4 ; /* segment extent (msb) */ 72 unsigned sd_xx:2 ; /* unused */ 73 unsigned sd_def32:1 ; /* default 32 vs 16 bit size */ 74 unsigned sd_gran:1 ; /* limit granularity (byte/page units)*/ 75 unsigned sd_hibase:8 ; /* segment base address (msb) */ 76} ; 77 78/* 79 * Gate descriptors (e.g. indirect descriptors) 80 */ 81struct gate_descriptor { 82 unsigned gd_looffset:16 ; /* gate offset (lsb) */ 83 unsigned gd_selector:16 ; /* gate segment selector */ 84 unsigned gd_stkcpy:5 ; /* number of stack wds to cpy */ 85 unsigned gd_xx:3 ; /* unused */ 86 unsigned gd_type:5 ; /* segment type */ 87 unsigned gd_dpl:2 ; /* segment descriptor priority level */ 88 unsigned gd_p:1 ; /* segment descriptor present */ 89 unsigned gd_hioffset:16 ; /* gate offset (msb) */ 90} ; 91 92/* 93 * Generic descriptor 94 */ 95union descriptor { 96 struct segment_descriptor sd; 97 struct gate_descriptor gd; 98}; 99 100 /* system segments and gate types */ 101#define SDT_SYSNULL 0 /* system null */ 102#define SDT_SYS286TSS 1 /* system 286 TSS available */ 103#define SDT_SYSLDT 2 /* system local descriptor table */ 104#define SDT_SYS286BSY 3 /* system 286 TSS busy */ 105#define SDT_SYS286CGT 4 /* system 286 call gate */ 106#define SDT_SYSTASKGT 5 /* system task gate */ 107#define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 108#define SDT_SYS286TGT 7 /* system 286 trap gate */ 109#define SDT_SYSNULL2 8 /* system null again */ 110#define SDT_SYS386TSS 9 /* system 386 TSS available */ 111#define SDT_SYSNULL3 10 /* system null again */ 112#define SDT_SYS386BSY 11 /* system 386 TSS busy */ 113#define SDT_SYS386CGT 12 /* system 386 call gate */ 114#define SDT_SYSNULL4 13 /* system null again */ 115#define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 116#define SDT_SYS386TGT 15 /* system 386 trap gate */ 117 118 /* memory segment types */ 119#define SDT_MEMRO 16 /* memory read only */ 120#define SDT_MEMROA 17 /* memory read only accessed */ 121#define SDT_MEMRW 18 /* memory read write */ 122#define SDT_MEMRWA 19 /* memory read write accessed */ 123#define SDT_MEMROD 20 /* memory read only expand dwn limit */ 124#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 125#define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 126#define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */ 127#define SDT_MEME 24 /* memory execute only */ 128#define SDT_MEMEA 25 /* memory execute only accessed */ 129#define SDT_MEMER 26 /* memory execute read */ 130#define SDT_MEMERA 27 /* memory execute read accessed */ 131#define SDT_MEMEC 28 /* memory execute only conforming */ 132#define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 133#define SDT_MEMERC 30 /* memory execute read conforming */ 134#define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 135 136/* 137 * Software definitions are in this convenient format, 138 * which are translated into inconvenient segment descriptors 139 * when needed to be used by the 386 hardware 140 */ 141 142struct soft_segment_descriptor { 143 unsigned ssd_base ; /* segment base address */ 144 unsigned ssd_limit ; /* segment extent */ 145 unsigned ssd_type:5 ; /* segment type */ 146 unsigned ssd_dpl:2 ; /* segment descriptor priority level */ 147 unsigned ssd_p:1 ; /* segment descriptor present */ 148 unsigned ssd_xx:4 ; /* unused */ 149 unsigned ssd_xx1:2 ; /* unused */ 150 unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */ 151 unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/ 152}; 153 154/* 155 * region descriptors, used to load gdt/idt tables before segments yet exist. 156 */ 157struct region_descriptor { 158 unsigned rd_limit:16; /* segment extent */ 159 unsigned rd_base:32 __packed; /* base address */ 160}; 161 162/* 163 * Segment Protection Exception code bits 164 */ 165 166#define SEGEX_EXT 0x01 /* recursive or externally induced */ 167#define SEGEX_IDT 0x02 /* interrupt descriptor table */ 168#define SEGEX_TI 0x04 /* local descriptor table */ 169 /* other bits are affected descriptor index */ 170#define SEGEX_IDX(s) (((s)>>3)&0x1fff) 171 172/* 173 * Size of IDT table 174 */ 175 176#define NIDT 256 /* 32 reserved, 0x80 syscall, most are h/w */ 177#define NRSVIDT 32 /* reserved entries for cpu exceptions */ 178 179/* 180 * Entries in the Interrupt Descriptor Table (IDT) 181 */ 182#define IDT_DE 0 /* #DE: Divide Error */ 183#define IDT_DB 1 /* #DB: Debug */ 184#define IDT_NMI 2 /* Nonmaskable External Interrupt */ 185#define IDT_BP 3 /* #BP: Breakpoint */ 186#define IDT_OF 4 /* #OF: Overflow */ 187#define IDT_BR 5 /* #BR: Bound Range Exceeded */ 188#define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */ 189#define IDT_NM 7 /* #NM: No Math Coprocessor */ 190#define IDT_DF 8 /* #DF: Double Fault */ 191#define IDT_FPUGP 9 /* Coprocessor Segment Overrun */ 192#define IDT_TS 10 /* #TS: Invalid TSS */ 193#define IDT_NP 11 /* #NP: Segment Not Present */ 194#define IDT_SS 12 /* #SS: Stack Segment Fault */ 195#define IDT_GP 13 /* #GP: General Protection Fault */ 196#define IDT_PF 14 /* #PF: Page Fault */ 197#define IDT_MF 16 /* #MF: FPU Floating-Point Error */ 198#define IDT_AC 17 /* #AC: Alignment Check */ 199#define IDT_MC 18 /* #MC: Machine Check */ 200#define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */ 201#define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */ 202#define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */ 203 204/* 205 * Entries in the Global Descriptor Table (GDT) 206 * Note that each 4 entries share a single 32 byte L1 cache line. 207 * Some of the fast syscall instructions require a specific order here. 208 */ 209#define GNULL_SEL 0 /* Null Descriptor */ 210#define GPRIV_SEL 1 /* SMP Per-Processor Private Data */ 211#define GUFS_SEL 2 /* User %fs Descriptor (order critical: 1) */ 212#define GUGS_SEL 3 /* User %gs Descriptor (order critical: 2) */ 213#define GCODE_SEL 4 /* Kernel Code Descriptor (order critical: 1) */ 214#define GDATA_SEL 5 /* Kernel Data Descriptor (order critical: 2) */ 215#define GUCODE_SEL 6 /* User Code Descriptor (order critical: 3) */ 216#define GUDATA_SEL 7 /* User Data Descriptor (order critical: 4) */ 217#define GBIOSLOWMEM_SEL 8 /* BIOS low memory access (must be entry 8) */ 218#define GPROC0_SEL 9 /* Task state process slot zero and up */ 219#define GLDT_SEL 10 /* Default User LDT */ 220#define GUSERLDT_SEL 11 /* User LDT */ 221#define GPANIC_SEL 12 /* Task state to consider panic from */ 222#define GBIOSCODE32_SEL 13 /* BIOS interface (32bit Code) */ 223#define GBIOSCODE16_SEL 14 /* BIOS interface (16bit Code) */ 224#define GBIOSDATA_SEL 15 /* BIOS interface (Data) */ 225#define GBIOSUTIL_SEL 16 /* BIOS interface (Utility) */ 226#define GBIOSARGS_SEL 17 /* BIOS interface (Arguments) */ 227#define GNDIS_SEL 18 /* For the NDIS layer */ 228 229#ifdef XEN 230#define NGDT 9 231#else 232#define NGDT 19 233#endif 234 235/* 236 * Entries in the Local Descriptor Table (LDT) 237 */ 238#define LSYS5CALLS_SEL 0 /* forced by intel BCS */ 239#define LSYS5SIGR_SEL 1 240#define L43BSDCALLS_SEL 2 /* notyet */ 241#define LUCODE_SEL 3 242#define LSOL26CALLS_SEL 4 /* Solaris >= 2.6 system call gate */ 243#define LUDATA_SEL 5 244/* separate stack, es,fs,gs sels ? */ 245/* #define LPOSIXCALLS_SEL 5*/ /* notyet */ 246#define LBSDICALLS_SEL 16 /* BSDI system call gate */ 247#define NLDT (LBSDICALLS_SEL + 1) 248 249#ifdef _KERNEL 250extern int _default_ldt; 251#ifdef XEN 252extern union descriptor *gdt; 253extern union descriptor *ldt; 254#else 255extern union descriptor gdt[]; 256extern union descriptor ldt[NLDT]; 257#endif 258extern struct soft_segment_descriptor gdt_segs[]; 259extern struct gate_descriptor *idt; 260extern struct region_descriptor r_gdt, r_idt; 261 262void lgdt(struct region_descriptor *rdp); 263void sdtossd(struct segment_descriptor *sdp, 264 struct soft_segment_descriptor *ssdp); 265void ssdtosd(struct soft_segment_descriptor *ssdp, 266 struct segment_descriptor *sdp); 267#endif /* _KERNEL */ 268 269#endif /* !_MACHINE_SEGMENTS_H_ */ 270