xref: /titanic_44/usr/src/uts/i86pc/os/mp_call.c (revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/thread.h>
32 #include <sys/cpuvar.h>
33 #include <sys/machsystm.h>
34 #include <sys/systm.h>
35 #include <sys/promif.h>
36 #include <sys/x_call.h>
37 
38 /*
39  * Interrupt another CPU.
40  * 	This is useful to make the other CPU go through a trap so that
41  *	it recognizes an address space trap (AST) for preempting a thread.
42  *
43  *	It is possible to be preempted here and be resumed on the CPU
44  *	being poked, so it isn't an error to poke the current CPU.
45  *	We could check this and still get preempted after the check, so
46  *	we don't bother.
47  */
48 void
49 poke_cpu(int cpun)
50 {
51 	if (panicstr)
52 		return;
53 	/*
54 	 * We don't need to receive an ACK from the CPU being poked,
55 	 * so just send out a directed interrupt.
56 	 */
57 	XC_TRACE(TT_XC_POKE_CPU, -1, cpun);
58 	send_dirint(cpun, XC_CPUPOKE_PIL);
59 }
60