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 * $FreeBSD$ 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 #include <x86/segments.h> 46 47 /* 48 * Software definitions are in this convenient format, 49 * which are translated into inconvenient segment descriptors 50 * when needed to be used by the 386 hardware 51 */ 52 53 struct soft_segment_descriptor { 54 unsigned ssd_base ; /* segment base address */ 55 unsigned ssd_limit ; /* segment extent */ 56 unsigned ssd_type:5 ; /* segment type */ 57 unsigned ssd_dpl:2 ; /* segment descriptor priority level */ 58 unsigned ssd_p:1 ; /* segment descriptor present */ 59 unsigned ssd_xx:4 ; /* unused */ 60 unsigned ssd_xx1:2 ; /* unused */ 61 unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */ 62 unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/ 63 }; 64 65 /* 66 * region descriptors, used to load gdt/idt tables before segments yet exist. 67 */ 68 struct region_descriptor { 69 unsigned rd_limit:16; /* segment extent */ 70 unsigned rd_base:32 __packed; /* base address */ 71 }; 72 73 /* 74 * Segment Protection Exception code bits 75 */ 76 77 #define SEGEX_EXT 0x01 /* recursive or externally induced */ 78 #define SEGEX_IDT 0x02 /* interrupt descriptor table */ 79 #define SEGEX_TI 0x04 /* local descriptor table */ 80 /* other bits are affected descriptor index */ 81 #define SEGEX_IDX(s) (((s)>>3)&0x1fff) 82 83 #ifdef _KERNEL 84 extern int _default_ldt; 85 #ifdef XEN 86 extern struct proc_ldt default_proc_ldt; 87 extern union descriptor *gdt; 88 extern union descriptor *ldt; 89 #else 90 extern union descriptor gdt[]; 91 extern union descriptor ldt[NLDT]; 92 #endif 93 extern struct soft_segment_descriptor gdt_segs[]; 94 extern struct gate_descriptor *idt; 95 extern struct region_descriptor r_gdt, r_idt; 96 97 void lgdt(struct region_descriptor *rdp); 98 void sdtossd(struct segment_descriptor *sdp, 99 struct soft_segment_descriptor *ssdp); 100 void ssdtosd(struct soft_segment_descriptor *ssdp, 101 struct segment_descriptor *sdp); 102 #endif /* _KERNEL */ 103 104 #endif /* !_MACHINE_SEGMENTS_H_ */ 105