xref: /freebsd/sys/i386/include/pcpu.h (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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 	int	pc_private_tss	/* flag indicating private tss */
59 
60 #if defined(lint)
61 
62 extern struct pcpu *pcpup;
63 
64 #define PCPU_GET(member)        (pcpup->pc_ ## member)
65 #define PCPU_PTR(member)        (&pcpup->pc_ ## member)
66 #define PCPU_SET(member,value)  (pcpup->pc_ ## member = (value))
67 
68 #elif defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF) \
69     && defined(__GNUCLIKE___OFFSETOF)
70 
71 /*
72  * Evaluates to the byte offset of the per-cpu variable name.
73  */
74 #define	__pcpu_offset(name)						\
75 	__offsetof(struct pcpu, name)
76 
77 /*
78  * Evaluates to the type of the per-cpu variable name.
79  */
80 #define	__pcpu_type(name)						\
81 	__typeof(((struct pcpu *)0)->name)
82 
83 /*
84  * Evaluates to the address of the per-cpu variable name.
85  */
86 #define	__PCPU_PTR(name) __extension__ ({				\
87 	__pcpu_type(name) *__p;						\
88 									\
89 	__asm __volatile("movl %%fs:%1,%0; addl %2,%0"			\
90 	    : "=r" (__p)						\
91 	    : "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace))),	\
92 	      "i" (__pcpu_offset(name)));				\
93 									\
94 	__p;								\
95 })
96 
97 /*
98  * Evaluates to the value of the per-cpu variable name.
99  */
100 #define	__PCPU_GET(name) __extension__ ({				\
101 	__pcpu_type(name) __result;					\
102 									\
103 	if (sizeof(__result) == 1) {					\
104 		u_char __b;						\
105 		__asm __volatile("movb %%fs:%1,%0"			\
106 		    : "=r" (__b)					\
107 		    : "m" (*(u_char *)(__pcpu_offset(name))));		\
108 		__result = *(__pcpu_type(name) *)(void *)&__b;		\
109 	} else if (sizeof(__result) == 2) {				\
110 		u_short __w;						\
111 		__asm __volatile("movw %%fs:%1,%0"			\
112 		    : "=r" (__w)					\
113 		    : "m" (*(u_short *)(__pcpu_offset(name))));		\
114 		__result = *(__pcpu_type(name) *)(void *)&__w;		\
115 	} else if (sizeof(__result) == 4) {				\
116 		u_int __i;						\
117 		__asm __volatile("movl %%fs:%1,%0"			\
118 		    : "=r" (__i)					\
119 		    : "m" (*(u_int *)(__pcpu_offset(name))));		\
120 		__result = *(__pcpu_type(name) *)(void *)&__i;		\
121 	} else {							\
122 		__result = *__PCPU_PTR(name);				\
123 	}								\
124 									\
125 	__result;							\
126 })
127 
128 /*
129  * Sets the value of the per-cpu variable name to value val.
130  */
131 #define	__PCPU_SET(name, val) {						\
132 	__pcpu_type(name) __val = (val);				\
133 									\
134 	if (sizeof(__val) == 1) {					\
135 		u_char __b;						\
136 		__b = *(u_char *)&__val;				\
137 		__asm __volatile("movb %1,%%fs:%0"			\
138 		    : "=m" (*(u_char *)(__pcpu_offset(name)))		\
139 		    : "r" (__b));					\
140 	} else if (sizeof(__val) == 2) {				\
141 		u_short __w;						\
142 		__w = *(u_short *)&__val;				\
143 		__asm __volatile("movw %1,%%fs:%0"			\
144 		    : "=m" (*(u_short *)(__pcpu_offset(name)))		\
145 		    : "r" (__w));					\
146 	} else if (sizeof(__val) == 4) {				\
147 		u_int __i;						\
148 		__i = *(u_int *)&__val;					\
149 		__asm __volatile("movl %1,%%fs:%0"			\
150 		    : "=m" (*(u_int *)(__pcpu_offset(name)))		\
151 		    : "r" (__i));					\
152 	} else {							\
153 		*__PCPU_PTR(name) = __val;				\
154 	}								\
155 }
156 
157 #define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
158 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
159 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
160 
161 static __inline struct thread *
162 __curthread(void)
163 {
164 	struct thread *td;
165 
166 	__asm __volatile("movl %%fs:0,%0" : "=r" (td));
167 	return (td);
168 }
169 #define	curthread (__curthread())
170 
171 #else
172 #error this file needs to be ported to your compiler
173 #endif
174 
175 #endif	/* _KERNEL */
176 
177 #endif	/* ! _MACHINE_PCPU_H_ */
178