xref: /freebsd/sys/amd64/include/pcpu.h (revision 42c159fe388a3765f69860c84183700af37aca8a)
1 /*-
2  * Copyright (c) Peter Wemm <peter@netplex.com.au>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _MACHINE_PCPU_H_
30 #define _MACHINE_PCPU_H_
31 
32 #ifdef _KERNEL
33 
34 #ifndef	__GNUC__
35 #error	gcc is required to use this file
36 #endif
37 
38 #include <machine/segments.h>
39 #include <machine/tss.h>
40 
41 /*
42  * The SMP parts are setup in pmap.c and locore.s for the BSP, and
43  * mp_machdep.c sets up the data for the AP's to "see" when they awake.
44  * The reason for doing it via a struct is so that an array of pointers
45  * to each CPU's data can be set up for things like "check curproc on all
46  * other processors"
47  */
48 #define	PCPU_MD_FIELDS							\
49 	struct	pcpu *pc_prvspace;		/* Self-reference */	\
50 	struct	i386tss pc_common_tss;					\
51 	struct	segment_descriptor pc_common_tssd;			\
52 	struct	segment_descriptor *pc_tss_gdt;				\
53 	int	pc_currentldt
54 
55 /*
56  * Evaluates to the byte offset of the per-cpu variable name.
57  */
58 #define	__pcpu_offset(name)						\
59 	__offsetof(struct pcpu, name)
60 
61 /*
62  * Evaluates to the type of the per-cpu variable name.
63  */
64 #define	__pcpu_type(name)						\
65 	__typeof(((struct pcpu *)0)->name)
66 
67 /*
68  * Evaluates to the address of the per-cpu variable name.
69  */
70 #define	__PCPU_PTR(name) ({						\
71 	__pcpu_type(name) *__p;						\
72 									\
73 	__asm __volatile("movl %%fs:%1,%0; addl %2,%0"			\
74 	    : "=r" (__p)						\
75 	    : "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace))),	\
76 	      "i" (__pcpu_offset(name)));				\
77 									\
78 	__p;								\
79 })
80 
81 /*
82  * Evaluates to the value of the per-cpu variable name.
83  */
84 #define	__PCPU_GET(name) ({						\
85 	__pcpu_type(name) __result;					\
86 									\
87 	if (sizeof(__result) == 1) {					\
88 		u_char __b;						\
89 		__asm __volatile("movb %%fs:%1,%0"			\
90 		    : "=r" (__b)					\
91 		    : "m" (*(u_char *)(__pcpu_offset(name))));		\
92 		__result = *(__pcpu_type(name) *)&__b;			\
93 	} else if (sizeof(__result) == 2) {				\
94 		u_short __w;						\
95 		__asm __volatile("movw %%fs:%1,%0"			\
96 		    : "=r" (__w)					\
97 		    : "m" (*(u_short *)(__pcpu_offset(name))));		\
98 		__result = *(__pcpu_type(name) *)&__w;			\
99 	} else if (sizeof(__result) == 4) {				\
100 		u_int __i;						\
101 		__asm __volatile("movl %%fs:%1,%0"			\
102 		    : "=r" (__i)					\
103 		    : "m" (*(u_int *)(__pcpu_offset(name))));		\
104 		__result = *(__pcpu_type(name) *)&__i;			\
105 	} else {							\
106 		__result = *__PCPU_PTR(name);				\
107 	}								\
108 									\
109 	__result;							\
110 })
111 
112 /*
113  * Sets the value of the per-cpu variable name to value val.
114  */
115 #define	__PCPU_SET(name, val) ({					\
116 	__pcpu_type(name) __val = (val);				\
117 									\
118 	if (sizeof(__val) == 1) {					\
119 		u_char __b;						\
120 		__b = *(u_char *)&__val;				\
121 		__asm __volatile("movb %1,%%fs:%0"			\
122 		    : "=m" (*(u_char *)(__pcpu_offset(name)))		\
123 		    : "r" (__b));					\
124 	} else if (sizeof(__val) == 2) {				\
125 		u_short __w;						\
126 		__w = *(u_short *)&__val;				\
127 		__asm __volatile("movw %1,%%fs:%0"			\
128 		    : "=m" (*(u_short *)(__pcpu_offset(name)))		\
129 		    : "r" (__w));					\
130 	} else if (sizeof(__val) == 4) {				\
131 		u_int __i;						\
132 		__i = *(u_int *)&__val;					\
133 		__asm __volatile("movl %1,%%fs:%0"			\
134 		    : "=m" (*(u_int *)(__pcpu_offset(name)))		\
135 		    : "r" (__i));					\
136 	} else {							\
137 		*__PCPU_PTR(name) = __val;				\
138 	}								\
139 })
140 
141 #define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
142 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
143 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
144 
145 #endif	/* _KERNEL */
146 
147 #endif	/* ! _MACHINE_PCPU_H_ */
148