kernel: Make SMP support default (and non-optional).
[dragonfly.git] / sys / platform / vkernel64 / include / thread.h
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1/*
2 * Copyright (c) 2006 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
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33 */
34
35#ifndef _MACHINE_THREAD_H_
36#define _MACHINE_THREAD_H_
37
da673940 38#include <machine/vframe.h>
da673940 39#include <machine/npx.h>
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40
41struct md_thread {
42 unsigned int mtd_unused; /* used to be mtd_cpl */
43 union savefpu *mtd_savefpu; /* pointer to current fpu context */
44 struct vextframe mtd_savevext;
45};
46
47#ifdef _KERNEL
48
49#define td_savefpu td_mach.mtd_savefpu
50#define td_tls td_mach.mtd_savevext.vx_tls
51#define td_savevext td_mach.mtd_savevext
52
53/*
54 * mycpu() retrieves the base of the current cpu's globaldata structure.
55 * Note that it is *NOT* volatile, meaning that the value may be cached by
56 * GCC. We have to force a dummy memory reference so gcc does not cache
57 * the gd pointer across a procedure call (which might block and cause us
58 * to wakeup on a different cpu).
59 *
60 * Also note that in DragonFly a thread can be preempted, but only by an
61 * interrupt thread and the original thread will resume after the
62 * interrupt thread finishes or blocks. A thread cannot move to another
63 * cpu preemptively or at all, in fact, while you are in the kernel, even
64 * if you block.
65 */
66
67struct globaldata;
68
69extern int __mycpu__dummy;
70
71static __inline
72struct globaldata *
73_get_mycpu(void)
74{
75 struct globaldata *gd;
76
77 __asm ("movq %%gs:globaldata,%0" : "=r" (gd) : "m"(__mycpu__dummy));
78 return(gd);
79}
80
81#define mycpu _get_mycpu()
da673940 82#define mycpuid (_get_mycpu()->gd_cpuid)
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83
84/*
85 * note: curthread is never NULL, but curproc can be. Also note that
86 * that only processes really use the PCB. Threads fill in some fields
87 * but mostly store contextual data on the stack and do not use (much of)
88 * the PCB.
89 */
90#define curthread mycpu->gd_curthread
91#define curproc curthread->td_proc
92
93#endif /* _KERNEL */
94
95#endif /* !_MACHINE_THREAD_H_ */