pcpu.h revision 166536 
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: head/sys/i386/include/pcpu.h 166536 2007-02-06 16:21:09Z bde $
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
62extern 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 || sizeof(__result) == 2 ||		\
104	    sizeof(__result) == 4) {					\
105		struct __s {						\
106			u_char	__b[MIN(sizeof(__pcpu_type(name)), 4)];	\
107		} __s;							\
108		__asm __volatile("mov %%fs:%1,%0"			\
109		    : "=r" (__s)					\
110		    : "m" (*(struct __s *)(__pcpu_offset(name))));	\
111		*(struct __s *)(void *)&__result = __s;			\
112	} else {							\
113		__result = *__PCPU_PTR(name);				\
114	}								\
115									\
116	__result;							\
117})
118
119/*
120 * Sets the value of the per-cpu variable name to value val.
121 */
122#define	__PCPU_SET(name, val) {						\
123	__pcpu_type(name) __val = (val);				\
124									\
125	if (sizeof(__val) == 1 || sizeof(__val) == 2 ||			\
126	    sizeof(__val) == 4) {					\
127		struct __s {						\
128			u_char	__b[MIN(sizeof(__pcpu_type(name)), 4)];	\
129		} __s;							\
130		__s = *(struct __s *)(void *)&__val;			\
131		__asm __volatile("mov %1,%%fs:%0"			\
132		    : "=m" (*(struct __s *)(__pcpu_offset(name)))	\
133		    : "r" (__s));					\
134	} else {							\
135		*__PCPU_PTR(name) = __val;				\
136	}								\
137}
138
139#define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
140#define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
141#define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
142
143static __inline struct thread *
144__curthread(void)
145{
146	struct thread *td;
147
148	__asm __volatile("movl %%fs:0,%0" : "=r" (td));
149	return (td);
150}
151#define	curthread (__curthread())
152
153#else
154#error this file needs to be ported to your compiler
155#endif
156
157#endif	/* _KERNEL */
158
159#endif	/* ! _MACHINE_PCPU_H_ */
160