pcb.h revision 237037 
1/*-
2 * Copyright (c) 2003 Peter Wemm.
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: @(#)pcb.h	5.10 (Berkeley) 5/12/91
34 * $FreeBSD: head/sys/amd64/include/pcb.h 237037 2012-06-13 22:53:56Z jkim $
35 */
36
37#ifndef _AMD64_PCB_H_
38#define _AMD64_PCB_H_
39
40/*
41 * AMD64 process control block
42 */
43#include <machine/fpu.h>
44#include <machine/segments.h>
45
46struct pcb {
47	register_t	pcb_r15;
48	register_t	pcb_r14;
49	register_t	pcb_r13;
50	register_t	pcb_r12;
51	register_t	pcb_rbp;
52	register_t	pcb_rsp;
53	register_t	pcb_rbx;
54	register_t	pcb_rip;
55	register_t	pcb_fsbase;
56	register_t	pcb_gsbase;
57	register_t	pcb_kgsbase;
58	register_t	pcb_cr0;
59	register_t	pcb_cr2;
60	register_t	pcb_cr3;
61	register_t	pcb_cr4;
62	register_t	pcb_dr0;
63	register_t	pcb_dr1;
64	register_t	pcb_dr2;
65	register_t	pcb_dr3;
66	register_t	pcb_dr6;
67	register_t	pcb_dr7;
68
69	struct region_descriptor pcb_gdt;
70	struct region_descriptor pcb_idt;
71	struct region_descriptor pcb_ldt;
72	uint16_t	pcb_tr;
73
74	u_int		pcb_flags;
75#define	PCB_FULL_IRET	0x01	/* full iret is required */
76#define	PCB_DBREGS	0x02	/* process using debug registers */
77#define	PCB_KERNFPU	0x04	/* kernel uses fpu */
78#define	PCB_FPUINITDONE	0x08	/* fpu state is initialized */
79#define	PCB_USERFPUINITDONE 0x10 /* fpu user state is initialized */
80#define	PCB_GS32BIT	0x20	/* linux gs switch */
81#define	PCB_32BIT	0x40	/* process has 32 bit context (segs etc) */
82
83	uint16_t	pcb_initial_fpucw;
84
85	/* copyin/out fault recovery */
86	caddr_t		pcb_onfault;
87
88	/* 32-bit segment descriptor */
89	struct user_segment_descriptor pcb_gs32sd;
90
91	/* local tss, with i/o bitmap; NULL for common */
92	struct amd64tss *pcb_tssp;
93
94	/* model specific registers */
95	register_t	pcb_efer;
96	register_t	pcb_star;
97	register_t	pcb_lstar;
98	register_t	pcb_cstar;
99	register_t	pcb_sfmask;
100	register_t	pcb_xsmask;
101
102	/* fpu context for suspend/resume */
103	void		*pcb_fpususpend;
104
105	struct savefpu	*pcb_save;
106
107	uint64_t	pcb_pad[3];
108};
109
110#ifdef _KERNEL
111struct trapframe;
112
113/*
114 * The pcb_flags is only modified by current thread, or by other threads
115 * when current thread is stopped.  However, current thread may change it
116 * from the interrupt context in cpu_switch(), or in the trap handler.
117 * When we read-modify-write pcb_flags from C sources, compiler may generate
118 * code that is not atomic regarding the interrupt handler.  If a trap or
119 * interrupt happens and any flag is modified from the handler, it can be
120 * clobbered with the cached value later.  Therefore, we implement setting
121 * and clearing flags with single-instruction functions, which do not race
122 * with possible modification of the flags from the trap or interrupt context,
123 * because traps and interrupts are executed only on instruction boundary.
124 */
125static __inline void
126set_pcb_flags(struct pcb *pcb, const u_int flags)
127{
128
129	__asm __volatile("orl %1,%0"
130	    : "=m" (pcb->pcb_flags) : "ir" (flags), "m" (pcb->pcb_flags)
131	    : "cc");
132}
133
134static __inline void
135clear_pcb_flags(struct pcb *pcb, const u_int flags)
136{
137
138	__asm __volatile("andl %1,%0"
139	    : "=m" (pcb->pcb_flags) : "ir" (~flags), "m" (pcb->pcb_flags)
140	    : "cc");
141}
142
143void	makectx(struct trapframe *, struct pcb *);
144int	savectx(struct pcb *) __returns_twice;
145void	resumectx(struct pcb *);
146
147#endif
148
149#endif /* _AMD64_PCB_H_ */
150