xref: /freebsd/sys/i386/include/pcpu.h (revision f0a75d274af375d15b97b830966b99a02b7db911)
1 /*-
2  * Copyright (c) Peter Wemm
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 "sys/cdefs.h is a prerequisite for this file"
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;		/* ACPI CPU id */		\
57 	u_int	pc_apic_id;						\
58 	int	pc_private_tss		/* Flag indicating private tss */
59 
60 #ifdef lint
61 
62 extern struct pcpu *pcpup;
63 
64 #define	PCPU_GET(member)	(pcpup->pc_ ## member)
65 #define	PCPU_LAZY_INC(member)	(++pcpup->pc_ ## member)
66 #define	PCPU_PTR(member)	(&pcpup->pc_ ## member)
67 #define	PCPU_SET(member, val)	(pcpup->pc_ ## member = (val))
68 
69 #elif defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF)
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) __res;					\
102 	struct __s {							\
103 		u_char	__b[MIN(sizeof(__pcpu_type(name)), 4)];		\
104 	} __s;								\
105 									\
106 	if (sizeof(__res) == 1 || sizeof(__res) == 2 ||			\
107 	    sizeof(__res) == 4) {					\
108 		__asm __volatile("mov %%fs:%1,%0"			\
109 		    : "=r" (__s)					\
110 		    : "m" (*(struct __s *)(__pcpu_offset(name))));	\
111 		*(struct __s *)(void *)&__res = __s;			\
112 	} else {							\
113 		__res = *__PCPU_PTR(name);				\
114 	}								\
115 	__res;								\
116 })
117 
118 /*
119  * Increments the value of the per-cpu counter name.  The implementation
120  * must be atomic with respect to interrupts.
121  */
122 #define	__PCPU_LAZY_INC(name) do {					\
123 	CTASSERT(sizeof(__pcpu_type(name)) == 1 ||			\
124 	    sizeof(__pcpu_type(name)) == 2 ||				\
125 	    sizeof(__pcpu_type(name)) == 4);				\
126 	if (sizeof(__pcpu_type(name)) == 1) {				\
127 		__asm __volatile("incb %%fs:%0"				\
128 		    : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
129 		    : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
130 	} else if (sizeof(__pcpu_type(name)) == 2) {			\
131 		__asm __volatile("incw %%fs:%0"				\
132 		    : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
133 		    : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
134 	} else if (sizeof(__pcpu_type(name)) == 4) {			\
135 		__asm __volatile("incl %%fs:%0"				\
136 		    : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
137 		    : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
138 	}								\
139 } while (0)
140 
141 /*
142  * Sets the value of the per-cpu variable name to value val.
143  */
144 #define	__PCPU_SET(name, val) {						\
145 	__pcpu_type(name) __val;					\
146 	struct __s {							\
147 		u_char	__b[MIN(sizeof(__pcpu_type(name)), 4)];		\
148 	} __s;								\
149 									\
150 	__val = (val);							\
151 	if (sizeof(__val) == 1 || sizeof(__val) == 2 ||			\
152 	    sizeof(__val) == 4) {					\
153 		__s = *(struct __s *)(void *)&__val;			\
154 		__asm __volatile("mov %1,%%fs:%0"			\
155 		    : "=m" (*(struct __s *)(__pcpu_offset(name)))	\
156 		    : "r" (__s));					\
157 	} else {							\
158 		*__PCPU_PTR(name) = __val;				\
159 	}								\
160 }
161 
162 #define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
163 #define	PCPU_LAZY_INC(member)	__PCPU_LAZY_INC(pc_ ## member)
164 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
165 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
166 
167 static __inline struct thread *
168 __curthread(void)
169 {
170 	struct thread *td;
171 
172 	__asm __volatile("movl %%fs:0,%0" : "=r" (td));
173 	return (td);
174 }
175 #define	curthread		(__curthread())
176 
177 #else /* !lint || defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF) */
178 
179 #error "this file needs to be ported to your compiler"
180 
181 #endif /* lint, etc. */
182 
183 #endif /* _KERNEL */
184 
185 #endif /* !_MACHINE_PCPU_H_ */
186