segments.h revision 210357
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 210357 2010-07-21 18:47:52Z rpaulo $ 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#define USD_GETBASE(sd) (((sd)->sd_lobase) | (sd)->sd_hibase << 24) 79#define USD_SETBASE(sd, b) (sd)->sd_lobase = (b); \ 80 (sd)->sd_hibase = ((b) >> 24); 81#define USD_GETLIMIT(sd) (((sd)->sd_lolimit) | (sd)->sd_hilimit << 16) 82#define USD_SETLIMIT(sd, l) (sd)->sd_lolimit = (l); \ 83 (sd)->sd_hilimit = ((l) >> 16); 84 85/* 86 * Gate descriptors (e.g. indirect descriptors) 87 */ 88struct gate_descriptor { 89 unsigned gd_looffset:16 ; /* gate offset (lsb) */ 90 unsigned gd_selector:16 ; /* gate segment selector */ 91 unsigned gd_stkcpy:5 ; /* number of stack wds to cpy */ 92 unsigned gd_xx:3 ; /* unused */ 93 unsigned gd_type:5 ; /* segment type */ 94 unsigned gd_dpl:2 ; /* segment descriptor priority level */ 95 unsigned gd_p:1 ; /* segment descriptor present */ 96 unsigned gd_hioffset:16 ; /* gate offset (msb) */ 97} ; 98 99/* 100 * Generic descriptor 101 */ 102union descriptor { 103 struct segment_descriptor sd; 104 struct gate_descriptor gd; 105}; 106 107 /* system segments and gate types */ 108#define SDT_SYSNULL 0 /* system null */ 109#define SDT_SYS286TSS 1 /* system 286 TSS available */ 110#define SDT_SYSLDT 2 /* system local descriptor table */ 111#define SDT_SYS286BSY 3 /* system 286 TSS busy */ 112#define SDT_SYS286CGT 4 /* system 286 call gate */ 113#define SDT_SYSTASKGT 5 /* system task gate */ 114#define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 115#define SDT_SYS286TGT 7 /* system 286 trap gate */ 116#define SDT_SYSNULL2 8 /* system null again */ 117#define SDT_SYS386TSS 9 /* system 386 TSS available */ 118#define SDT_SYSNULL3 10 /* system null again */ 119#define SDT_SYS386BSY 11 /* system 386 TSS busy */ 120#define SDT_SYS386CGT 12 /* system 386 call gate */ 121#define SDT_SYSNULL4 13 /* system null again */ 122#define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 123#define SDT_SYS386TGT 15 /* system 386 trap gate */ 124 125 /* memory segment types */ 126#define SDT_MEMRO 16 /* memory read only */ 127#define SDT_MEMROA 17 /* memory read only accessed */ 128#define SDT_MEMRW 18 /* memory read write */ 129#define SDT_MEMRWA 19 /* memory read write accessed */ 130#define SDT_MEMROD 20 /* memory read only expand dwn limit */ 131#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 132#define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 133#define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */ 134#define SDT_MEME 24 /* memory execute only */ 135#define SDT_MEMEA 25 /* memory execute only accessed */ 136#define SDT_MEMER 26 /* memory execute read */ 137#define SDT_MEMERA 27 /* memory execute read accessed */ 138#define SDT_MEMEC 28 /* memory execute only conforming */ 139#define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 140#define SDT_MEMERC 30 /* memory execute read conforming */ 141#define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 142 143/* 144 * Software definitions are in this convenient format, 145 * which are translated into inconvenient segment descriptors 146 * when needed to be used by the 386 hardware 147 */ 148 149struct soft_segment_descriptor { 150 unsigned ssd_base ; /* segment base address */ 151 unsigned ssd_limit ; /* segment extent */ 152 unsigned ssd_type:5 ; /* segment type */ 153 unsigned ssd_dpl:2 ; /* segment descriptor priority level */ 154 unsigned ssd_p:1 ; /* segment descriptor present */ 155 unsigned ssd_xx:4 ; /* unused */ 156 unsigned ssd_xx1:2 ; /* unused */ 157 unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */ 158 unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/ 159}; 160 161/* 162 * region descriptors, used to load gdt/idt tables before segments yet exist. 163 */ 164struct region_descriptor { 165 unsigned rd_limit:16; /* segment extent */ 166 unsigned rd_base:32 __packed; /* base address */ 167}; 168 169/* 170 * Segment Protection Exception code bits 171 */ 172 173#define SEGEX_EXT 0x01 /* recursive or externally induced */ 174#define SEGEX_IDT 0x02 /* interrupt descriptor table */ 175#define SEGEX_TI 0x04 /* local descriptor table */ 176 /* other bits are affected descriptor index */ 177#define SEGEX_IDX(s) (((s)>>3)&0x1fff) 178 179/* 180 * Size of IDT table 181 */ 182 183#define NIDT 256 /* 32 reserved, 0x80 syscall, most are h/w */ 184#define NRSVIDT 32 /* reserved entries for cpu exceptions */ 185 186/* 187 * Entries in the Interrupt Descriptor Table (IDT) 188 */ 189#define IDT_DE 0 /* #DE: Divide Error */ 190#define IDT_DB 1 /* #DB: Debug */ 191#define IDT_NMI 2 /* Nonmaskable External Interrupt */ 192#define IDT_BP 3 /* #BP: Breakpoint */ 193#define IDT_OF 4 /* #OF: Overflow */ 194#define IDT_BR 5 /* #BR: Bound Range Exceeded */ 195#define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */ 196#define IDT_NM 7 /* #NM: No Math Coprocessor */ 197#define IDT_DF 8 /* #DF: Double Fault */ 198#define IDT_FPUGP 9 /* Coprocessor Segment Overrun */ 199#define IDT_TS 10 /* #TS: Invalid TSS */ 200#define IDT_NP 11 /* #NP: Segment Not Present */ 201#define IDT_SS 12 /* #SS: Stack Segment Fault */ 202#define IDT_GP 13 /* #GP: General Protection Fault */ 203#define IDT_PF 14 /* #PF: Page Fault */ 204#define IDT_MF 16 /* #MF: FPU Floating-Point Error */ 205#define IDT_AC 17 /* #AC: Alignment Check */ 206#define IDT_MC 18 /* #MC: Machine Check */ 207#define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */ 208#define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */ 209#define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */ 210 211/* 212 * Entries in the Global Descriptor Table (GDT) 213 * Note that each 4 entries share a single 32 byte L1 cache line. 214 * Some of the fast syscall instructions require a specific order here. 215 */ 216#define GNULL_SEL 0 /* Null Descriptor */ 217#define GPRIV_SEL 1 /* SMP Per-Processor Private Data */ 218#define GUFS_SEL 2 /* User %fs Descriptor (order critical: 1) */ 219#define GUGS_SEL 3 /* User %gs Descriptor (order critical: 2) */ 220#define GCODE_SEL 4 /* Kernel Code Descriptor (order critical: 1) */ 221#define GDATA_SEL 5 /* Kernel Data Descriptor (order critical: 2) */ 222#define GUCODE_SEL 6 /* User Code Descriptor (order critical: 3) */ 223#define GUDATA_SEL 7 /* User Data Descriptor (order critical: 4) */ 224#define GBIOSLOWMEM_SEL 8 /* BIOS low memory access (must be entry 8) */ 225#define GPROC0_SEL 9 /* Task state process slot zero and up */ 226#define GLDT_SEL 10 /* Default User LDT */ 227#define GUSERLDT_SEL 11 /* User LDT */ 228#define GPANIC_SEL 12 /* Task state to consider panic from */ 229#define GBIOSCODE32_SEL 13 /* BIOS interface (32bit Code) */ 230#define GBIOSCODE16_SEL 14 /* BIOS interface (16bit Code) */ 231#define GBIOSDATA_SEL 15 /* BIOS interface (Data) */ 232#define GBIOSUTIL_SEL 16 /* BIOS interface (Utility) */ 233#define GBIOSARGS_SEL 17 /* BIOS interface (Arguments) */ 234#define GNDIS_SEL 18 /* For the NDIS layer */ 235 236#ifdef XEN 237#define NGDT 9 238#else 239#define NGDT 19 240#endif 241 242/* 243 * Entries in the Local Descriptor Table (LDT) 244 */ 245#define LSYS5CALLS_SEL 0 /* forced by intel BCS */ 246#define LSYS5SIGR_SEL 1 247#define L43BSDCALLS_SEL 2 /* notyet */ 248#define LUCODE_SEL 3 249#define LSOL26CALLS_SEL 4 /* Solaris >= 2.6 system call gate */ 250#define LUDATA_SEL 5 251/* separate stack, es,fs,gs sels ? */ 252/* #define LPOSIXCALLS_SEL 5*/ /* notyet */ 253#define LBSDICALLS_SEL 16 /* BSDI system call gate */ 254#define NLDT (LBSDICALLS_SEL + 1) 255 256#ifdef _KERNEL 257extern int _default_ldt; 258#ifdef XEN 259extern union descriptor *gdt; 260extern union descriptor *ldt; 261#else 262extern union descriptor gdt[]; 263extern union descriptor ldt[NLDT]; 264#endif 265extern struct soft_segment_descriptor gdt_segs[]; 266extern struct gate_descriptor *idt; 267extern struct region_descriptor r_gdt, r_idt; 268 269void lgdt(struct region_descriptor *rdp); 270void sdtossd(struct segment_descriptor *sdp, 271 struct soft_segment_descriptor *ssdp); 272void ssdtosd(struct soft_segment_descriptor *ssdp, 273 struct segment_descriptor *sdp); 274#endif /* _KERNEL */ 275 276#endif /* !_MACHINE_SEGMENTS_H_ */ 277