2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
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
34 * Machine independant code should not directly include this file.
36 * $DragonFly: src/sys/platform/pc32/include/thread.h,v 1.7 2004/07/16 05:48:46 dillon Exp $
39 #ifndef _MACHINE_THREAD_H_
40 #define _MACHINE_THREAD_H_
46 union savefpu *mtd_savefpu;
51 #define td_cpl td_mach.mtd_cpl
52 #define td_savefpu td_mach.mtd_savefpu
55 * mycpu() retrieves the base of the current cpu's globaldata structure.
56 * Note that it is *NOT* volatile, meaning that the value may be cached by
57 * GCC. We have to force a dummy memory reference so gcc does not cache
58 * the gd pointer across a procedure call (which might block and cause us
59 * to wakeup on a different cpu).
61 * Also note that in TurtleBSD a thread can be preempted, but it cannot
62 * move to another cpu preemptively so the 'gd' pointer is good until you
68 extern int __mycpu__dummy;
74 struct globaldata *gd;
76 __asm ("movl %%fs:globaldata,%0" : "=r" (gd) : "m"(__mycpu__dummy));
80 #define mycpu _get_mycpu()
83 * note: curthread is never NULL, but curproc can be. Also note that
84 * in Turtle, the current pcb is stored in the thread structure.
86 #define curthread mycpu->gd_curthread
87 #define curproc curthread->td_proc
91 #endif /* !_MACHINE_THREAD_H_ */