kernel: Make SMP support default (and non-optional).
[dragonfly.git] / sys / platform / pc64 / include / thread.h
CommitLineData
39923942 1/*
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2 * Copyright (c) 2003 Matt Dillon <dillon@backplane.com>
3 * Copyright (c) 2008 The DragonFly Project.
4 * All rights reserved.
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5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * Machine independant code should not directly include this file.
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28 */
29
30#ifndef _MACHINE_THREAD_H_
31#define _MACHINE_THREAD_H_
32
d7f50089 33#include <machine/segments.h>
d7f50089 34
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35struct md_thread {
36 unsigned int mtd_cpl;
d7f50089 37 union savefpu *mtd_savefpu;
c8fe38ae 38 struct savetls mtd_savetls;
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39};
40
41#ifdef _KERNEL
42
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43#define td_cpl td_mach.mtd_cpl
44#define td_tls td_mach.mtd_savetls
45#define td_savefpu td_mach.mtd_savefpu
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46
47/*
48 * mycpu() retrieves the base of the current cpu's globaldata structure.
49 * Note that it is *NOT* volatile, meaning that the value may be cached by
50 * GCC. We have to force a dummy memory reference so gcc does not cache
51 * the gd pointer across a procedure call (which might block and cause us
52 * to wakeup on a different cpu).
53 *
54 * Also note that in DragonFly a thread can be preempted, but it cannot
55 * move to another cpu preemptively so the 'gd' pointer is good until you
56 * block.
57 */
58
59struct globaldata;
60
61extern int __mycpu__dummy;
62
63static __inline
64struct globaldata *
65_get_mycpu(void)
66{
67 struct globaldata *gd;
68
c8fe38ae 69 __asm ("movq %%gs:globaldata,%0" : "=r" (gd) : "m"(__mycpu__dummy));
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70 return(gd);
71}
72
73#define mycpu _get_mycpu()
d7f50089 74#define mycpuid (_get_mycpu()->gd_cpuid)
d7f50089 75
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76/*
77 * note: curthread is never NULL, but curproc can be. Also note that
78 * in DragonFly, the current pcb is stored in the thread structure.
79 */
80#define curthread mycpu->gd_curthread
81#define curproc curthread->td_proc
82
83#endif /* _KERNEL */
84
85#endif /* !_MACHINE_THREAD_H_ */