xref: /freebsd/sys/i386/include/pcpu.h (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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 #include <machine/segments.h>
35 #include <machine/tss.h>
36 
37 /*
38  * The SMP parts are setup in pmap.c and locore.s for the BSP, and
39  * mp_machdep.c sets up the data for the AP's to "see" when they awake.
40  * The reason for doing it via a struct is so that an array of pointers
41  * to each CPU's data can be set up for things like "check curproc on all
42  * other processors"
43  */
44 #define	PCPU_MD_FIELDS							\
45 	struct	pcpu *pc_prvspace;		/* Self-reference */	\
46 	struct	pmap *pc_curpmap;					\
47 	struct	i386tss pc_common_tss;					\
48 	struct	segment_descriptor pc_common_tssd;			\
49 	struct	segment_descriptor *pc_tss_gdt;				\
50 	int	pc_currentldt;						\
51 	u_int	pc_acpi_id;						\
52 	u_int	pc_apic_id
53 
54 #if defined(lint)
55 
56 extern struct pcpu *pcpup;
57 
58 #define PCPU_GET(member)        (pcpup->pc_ ## member)
59 #define PCPU_PTR(member)        (&pcpup->pc_ ## member)
60 #define PCPU_SET(member,value)  (pcpup->pc_ ## member = (value))
61 
62 #elif defined(__GNUC__) || defined (__INTEL_COMPILER)
63 
64 /*
65  * Evaluates to the byte offset of the per-cpu variable name.
66  */
67 #define	__pcpu_offset(name)						\
68 	__offsetof(struct pcpu, name)
69 
70 /*
71  * Evaluates to the type of the per-cpu variable name.
72  */
73 #define	__pcpu_type(name)						\
74 	__typeof(((struct pcpu *)0)->name)
75 
76 /*
77  * Evaluates to the address of the per-cpu variable name.
78  */
79 #define	__PCPU_PTR(name) __extension__ ({				\
80 	__pcpu_type(name) *__p;						\
81 									\
82 	__asm __volatile("movl %%fs:%1,%0; addl %2,%0"			\
83 	    : "=r" (__p)						\
84 	    : "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace))),	\
85 	      "i" (__pcpu_offset(name)));				\
86 									\
87 	__p;								\
88 })
89 
90 /*
91  * Evaluates to the value of the per-cpu variable name.
92  */
93 #define	__PCPU_GET(name) __extension__ ({				\
94 	__pcpu_type(name) __result;					\
95 									\
96 	if (sizeof(__result) == 1) {					\
97 		u_char __b;						\
98 		__asm __volatile("movb %%fs:%1,%0"			\
99 		    : "=r" (__b)					\
100 		    : "m" (*(u_char *)(__pcpu_offset(name))));		\
101 		__result = *(__pcpu_type(name) *)(void *)&__b;		\
102 	} else if (sizeof(__result) == 2) {				\
103 		u_short __w;						\
104 		__asm __volatile("movw %%fs:%1,%0"			\
105 		    : "=r" (__w)					\
106 		    : "m" (*(u_short *)(__pcpu_offset(name))));		\
107 		__result = *(__pcpu_type(name) *)(void *)&__w;		\
108 	} else if (sizeof(__result) == 4) {				\
109 		u_int __i;						\
110 		__asm __volatile("movl %%fs:%1,%0"			\
111 		    : "=r" (__i)					\
112 		    : "m" (*(u_int *)(__pcpu_offset(name))));		\
113 		__result = *(__pcpu_type(name) *)(void *)&__i;		\
114 	} else {							\
115 		__result = *__PCPU_PTR(name);				\
116 	}								\
117 									\
118 	__result;							\
119 })
120 
121 /*
122  * Sets the value of the per-cpu variable name to value val.
123  */
124 #define	__PCPU_SET(name, val) {						\
125 	__pcpu_type(name) __val = (val);				\
126 									\
127 	if (sizeof(__val) == 1) {					\
128 		u_char __b;						\
129 		__b = *(u_char *)&__val;				\
130 		__asm __volatile("movb %1,%%fs:%0"			\
131 		    : "=m" (*(u_char *)(__pcpu_offset(name)))		\
132 		    : "r" (__b));					\
133 	} else if (sizeof(__val) == 2) {				\
134 		u_short __w;						\
135 		__w = *(u_short *)&__val;				\
136 		__asm __volatile("movw %1,%%fs:%0"			\
137 		    : "=m" (*(u_short *)(__pcpu_offset(name)))		\
138 		    : "r" (__w));					\
139 	} else if (sizeof(__val) == 4) {				\
140 		u_int __i;						\
141 		__i = *(u_int *)&__val;					\
142 		__asm __volatile("movl %1,%%fs:%0"			\
143 		    : "=m" (*(u_int *)(__pcpu_offset(name)))		\
144 		    : "r" (__i));					\
145 	} else {							\
146 		*__PCPU_PTR(name) = __val;				\
147 	}								\
148 }
149 
150 #define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
151 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
152 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
153 
154 static __inline struct thread *
155 __curthread(void)
156 {
157 	struct thread *td;
158 
159 	__asm __volatile("movl %%fs:0,%0" : "=r" (td));
160 	return (td);
161 }
162 #define	curthread (__curthread())
163 
164 #else
165 #error gcc or lint is required to use this file
166 #endif
167 
168 #endif	/* _KERNEL */
169 
170 #endif	/* ! _MACHINE_PCPU_H_ */
171