2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1989, 1990 William F. Jolitz
5 * Copyright (c) 1990 The Regents of the University of California.
8 * This code is derived from software contributed to Berkeley by
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35 * from: @(#)segments.h 7.1 (Berkeley) 5/9/91
39 #ifndef _MACHINE_SEGMENTS_H_
40 #define _MACHINE_SEGMENTS_H_
43 * AMD64 Segmentation Data Structures and definitions
46 #include <x86/segments.h>
49 * System segment descriptors (128 bit wide)
51 struct system_segment_descriptor {
52 u_int64_t sd_lolimit:16; /* segment extent (lsb) */
53 u_int64_t sd_lobase:24; /* segment base address (lsb) */
54 u_int64_t sd_type:5; /* segment type */
55 u_int64_t sd_dpl:2; /* segment descriptor priority level */
56 u_int64_t sd_p:1; /* segment descriptor present */
57 u_int64_t sd_hilimit:4; /* segment extent (msb) */
58 u_int64_t sd_xx0:3; /* unused */
59 u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
60 u_int64_t sd_hibase:40 __packed;/* segment base address (msb) */
62 u_int64_t sd_mbz:5; /* MUST be zero */
67 * Software definitions are in this convenient format,
68 * which are translated into inconvenient segment descriptors
69 * when needed to be used by the 386 hardware
72 struct soft_segment_descriptor {
73 unsigned long ssd_base; /* segment base address */
74 unsigned long ssd_limit; /* segment extent */
75 unsigned long ssd_type:5; /* segment type */
76 unsigned long ssd_dpl:2; /* segment descriptor priority level */
77 unsigned long ssd_p:1; /* segment descriptor present */
78 unsigned long ssd_long:1; /* long mode (for %cs) */
79 unsigned long ssd_def32:1; /* default 32 vs 16 bit size */
80 unsigned long ssd_gran:1; /* limit granularity (byte/page units)*/
84 * region descriptors, used to load gdt/idt tables before segments yet exist.
86 struct region_descriptor {
87 uint64_t rd_limit:16; /* segment extent */
88 uint64_t rd_base:64 __packed; /* base address */
92 extern struct soft_segment_descriptor gdt_segs[];
93 extern struct gate_descriptor *idt;
94 extern struct region_descriptor r_idt;
96 void lgdt(struct region_descriptor *rdp);
97 void sdtossd(struct user_segment_descriptor *sdp,
98 struct soft_segment_descriptor *ssdp);
99 void ssdtosd(struct soft_segment_descriptor *ssdp,
100 struct user_segment_descriptor *sdp);
101 void ssdtosyssd(struct soft_segment_descriptor *ssdp,
102 struct system_segment_descriptor *sdp);
103 void update_gdt_gsbase(struct thread *td, uint32_t base);
104 void update_gdt_fsbase(struct thread *td, uint32_t base);
107 #endif /* !_MACHINE_SEGMENTS_H_ */