xref: /freebsd/sys/i386/include/pcpu.h (revision 262e143bd46171a6415a5b28af260a5efa2a3db8)
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 #ifndef _SYS_CDEFS_H_
33 #error this file needs sys/cdefs.h as a prerequisite
34 #endif
35 
36 #ifdef _KERNEL
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	pmap *pc_curpmap;					\
51 	struct	i386tss pc_common_tss;					\
52 	struct	segment_descriptor pc_common_tssd;			\
53 	struct	segment_descriptor *pc_tss_gdt;				\
54 	struct	segment_descriptor *pc_fsgs_gdt;			\
55 	int	pc_currentldt;						\
56 	u_int	pc_acpi_id;						\
57 	u_int	pc_apic_id
58 
59 #if defined(lint)
60 
61 extern struct pcpu *pcpup;
62 
63 #define PCPU_GET(member)        (pcpup->pc_ ## member)
64 #define PCPU_PTR(member)        (&pcpup->pc_ ## member)
65 #define PCPU_SET(member,value)  (pcpup->pc_ ## member = (value))
66 
67 #elif defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF) \
68     && defined(__GNUCLIKE___OFFSETOF)
69 
70 /*
71  * Evaluates to the byte offset of the per-cpu variable name.
72  */
73 #define	__pcpu_offset(name)						\
74 	__offsetof(struct pcpu, name)
75 
76 /*
77  * Evaluates to the type of the per-cpu variable name.
78  */
79 #define	__pcpu_type(name)						\
80 	__typeof(((struct pcpu *)0)->name)
81 
82 /*
83  * Evaluates to the address of the per-cpu variable name.
84  */
85 #define	__PCPU_PTR(name) __extension__ ({				\
86 	__pcpu_type(name) *__p;						\
87 									\
88 	__asm __volatile("movl %%fs:%1,%0; addl %2,%0"			\
89 	    : "=r" (__p)						\
90 	    : "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace))),	\
91 	      "i" (__pcpu_offset(name)));				\
92 									\
93 	__p;								\
94 })
95 
96 /*
97  * Evaluates to the value of the per-cpu variable name.
98  */
99 #define	__PCPU_GET(name) __extension__ ({				\
100 	__pcpu_type(name) __result;					\
101 									\
102 	if (sizeof(__result) == 1) {					\
103 		u_char __b;						\
104 		__asm __volatile("movb %%fs:%1,%0"			\
105 		    : "=r" (__b)					\
106 		    : "m" (*(u_char *)(__pcpu_offset(name))));		\
107 		__result = *(__pcpu_type(name) *)(void *)&__b;		\
108 	} else if (sizeof(__result) == 2) {				\
109 		u_short __w;						\
110 		__asm __volatile("movw %%fs:%1,%0"			\
111 		    : "=r" (__w)					\
112 		    : "m" (*(u_short *)(__pcpu_offset(name))));		\
113 		__result = *(__pcpu_type(name) *)(void *)&__w;		\
114 	} else if (sizeof(__result) == 4) {				\
115 		u_int __i;						\
116 		__asm __volatile("movl %%fs:%1,%0"			\
117 		    : "=r" (__i)					\
118 		    : "m" (*(u_int *)(__pcpu_offset(name))));		\
119 		__result = *(__pcpu_type(name) *)(void *)&__i;		\
120 	} else {							\
121 		__result = *__PCPU_PTR(name);				\
122 	}								\
123 									\
124 	__result;							\
125 })
126 
127 /*
128  * Sets the value of the per-cpu variable name to value val.
129  */
130 #define	__PCPU_SET(name, val) {						\
131 	__pcpu_type(name) __val = (val);				\
132 									\
133 	if (sizeof(__val) == 1) {					\
134 		u_char __b;						\
135 		__b = *(u_char *)&__val;				\
136 		__asm __volatile("movb %1,%%fs:%0"			\
137 		    : "=m" (*(u_char *)(__pcpu_offset(name)))		\
138 		    : "r" (__b));					\
139 	} else if (sizeof(__val) == 2) {				\
140 		u_short __w;						\
141 		__w = *(u_short *)&__val;				\
142 		__asm __volatile("movw %1,%%fs:%0"			\
143 		    : "=m" (*(u_short *)(__pcpu_offset(name)))		\
144 		    : "r" (__w));					\
145 	} else if (sizeof(__val) == 4) {				\
146 		u_int __i;						\
147 		__i = *(u_int *)&__val;					\
148 		__asm __volatile("movl %1,%%fs:%0"			\
149 		    : "=m" (*(u_int *)(__pcpu_offset(name)))		\
150 		    : "r" (__i));					\
151 	} else {							\
152 		*__PCPU_PTR(name) = __val;				\
153 	}								\
154 }
155 
156 #define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
157 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
158 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
159 
160 static __inline struct thread *
161 __curthread(void)
162 {
163 	struct thread *td;
164 
165 	__asm __volatile("movl %%fs:0,%0" : "=r" (td));
166 	return (td);
167 }
168 #define	curthread (__curthread())
169 
170 #else
171 #error this file needs to be ported to your compiler
172 #endif
173 
174 #endif	/* _KERNEL */
175 
176 #endif	/* ! _MACHINE_PCPU_H_ */
177