xref: /freebsd/sys/amd64/include/pcb.h (revision 7aa65846327fe5bc7e5961c2f7fd0c61f2ec0b01)
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  * $FreeBSD$
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 
46 struct 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 	struct savefpu	*pcb_save;
95 
96 	uint64_t	pcb_pad[2];
97 };
98 
99 #ifdef _KERNEL
100 struct trapframe;
101 
102 /*
103  * The pcb_flags is only modified by current thread, or by other threads
104  * when current thread is stopped.  However, current thread may change it
105  * from the interrupt context in cpu_switch(), or in the trap handler.
106  * When we read-modify-write pcb_flags from C sources, compiler may generate
107  * code that is not atomic regarding the interrupt handler.  If a trap or
108  * interrupt happens and any flag is modified from the handler, it can be
109  * clobbered with the cached value later.  Therefore, we implement setting
110  * and clearing flags with single-instruction functions, which do not race
111  * with possible modification of the flags from the trap or interrupt context,
112  * because traps and interrupts are executed only on instruction boundary.
113  */
114 static __inline void
115 set_pcb_flags(struct pcb *pcb, const u_int flags)
116 {
117 
118 	__asm __volatile("orl %1,%0"
119 	    : "=m" (pcb->pcb_flags) : "ir" (flags), "m" (pcb->pcb_flags)
120 	    : "cc");
121 }
122 
123 static __inline void
124 clear_pcb_flags(struct pcb *pcb, const u_int flags)
125 {
126 
127 	__asm __volatile("andl %1,%0"
128 	    : "=m" (pcb->pcb_flags) : "ir" (~flags), "m" (pcb->pcb_flags)
129 	    : "cc");
130 }
131 
132 void	makectx(struct trapframe *, struct pcb *);
133 int	savectx(struct pcb *);
134 
135 #endif
136 
137 #endif /* _AMD64_PCB_H_ */
138