xref: /dragonfly/sys/cpu/x86_64/include/psl.h (revision cd1c6085)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)psl.h	5.2 (Berkeley) 1/18/91
37  * $FreeBSD: src/sys/amd64/include/psl.h,v 1.12 2003/05/01 01:05:23 peter Exp $
38  */
39 
40 #ifndef _CPU_PSL_H_
41 #define	_CPU_PSL_H_
42 
43 /*
44  * 386 processor status longword.
45  */
46 #define	PSL_C		0x00000001	/* carry bit */
47 #define	PSL_PF		0x00000004	/* parity bit */
48 #define	PSL_AF		0x00000010	/* bcd carry bit */
49 #define	PSL_Z		0x00000040	/* zero bit */
50 #define	PSL_N		0x00000080	/* negative bit */
51 #define	PSL_T		0x00000100	/* trace enable bit */
52 #define	PSL_I		0x00000200	/* interrupt enable bit */
53 #define	PSL_D		0x00000400	/* string instruction direction bit */
54 #define	PSL_V		0x00000800	/* overflow bit */
55 #define	PSL_IOPL	0x00003000	/* i/o privilege level */
56 #define	PSL_NT		0x00004000	/* nested task bit */
57 #define	PSL_RF		0x00010000	/* resume flag bit */
58 #define PSL_VM_UNSUPP	0x00020000 	/* virtual 8086 mode bit */
59 #define	PSL_AC		0x00040000	/* alignment checking */
60 /* #define PSL_VIF	0x00080000 */	/* virtual interrupt enable */
61 /* #define PSL_VIP	0x00100000 */	/* virtual interrupt pending */
62 #define	PSL_ID		0x00200000	/* identification bit */
63 
64 /*
65  * The i486 manual says that we are not supposed to change reserved flags,
66  * but this is too much trouble since the reserved flags depend on the cpu
67  * and setting them to their historical values works in practice.
68  */
69 #define	PSL_RESERVED_DEFAULT	0x00000002
70 
71 /*
72  * Initial flags for kernel and user mode.  The kernel later inherits
73  * PSL_I and some other flags from user mode.
74  */
75 #define	PSL_KERNEL	PSL_RESERVED_DEFAULT
76 #define	PSL_USER	(PSL_RESERVED_DEFAULT | PSL_I)
77 
78 /*
79  * Bits that can be changed in user mode on 486's.  We allow these bits
80  * to be changed using ptrace(), sigreturn() and procfs.  Setting PS_NT
81  * is undesirable but it may as well be allowed since users can inflict
82  * it on the kernel directly.  Changes to PSL_AC are silently ignored on
83  * 386's.
84  */
85 #define	PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \
86 			| PSL_D | PSL_V | PSL_NT | PSL_AC | PSL_ID)
87 
88 #endif /* !_CPU_PSL_H_ */
89