1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * Facilities for cross-processor subroutine calls using "mailbox" interrupts.
31*0Sstevel@tonic-gate  */
32*0Sstevel@tonic-gate 
33*0Sstevel@tonic-gate #include <sys/types.h>
34*0Sstevel@tonic-gate #include <sys/thread.h>
35*0Sstevel@tonic-gate #include <sys/cpuvar.h>
36*0Sstevel@tonic-gate #include <sys/x_call.h>
37*0Sstevel@tonic-gate #include <sys/systm.h>
38*0Sstevel@tonic-gate #include <sys/machsystm.h>
39*0Sstevel@tonic-gate #include <sys/intr.h>
40*0Sstevel@tonic-gate 
41*0Sstevel@tonic-gate /*
42*0Sstevel@tonic-gate  * Interrupt another CPU.
43*0Sstevel@tonic-gate  * 	This is useful to make the other CPU go through a trap so that
44*0Sstevel@tonic-gate  *	it recognizes an address space trap (AST) for preempting a thread.
45*0Sstevel@tonic-gate  *
46*0Sstevel@tonic-gate  *	It is possible to be preempted here and be resumed on the CPU
47*0Sstevel@tonic-gate  *	being poked, so it isn't an error to poke the current CPU.
48*0Sstevel@tonic-gate  *	We could check this and still get preempted after the check, so
49*0Sstevel@tonic-gate  *	we don't bother.
50*0Sstevel@tonic-gate  */
51*0Sstevel@tonic-gate void
52*0Sstevel@tonic-gate poke_cpu(int cpun)
53*0Sstevel@tonic-gate {
54*0Sstevel@tonic-gate 	uint32_t *ptr = (uint32_t *)&cpu[cpun]->cpu_m.poke_cpu_outstanding;
55*0Sstevel@tonic-gate 
56*0Sstevel@tonic-gate 	/*
57*0Sstevel@tonic-gate 	 * If panicstr is set or a poke_cpu is already pending,
58*0Sstevel@tonic-gate 	 * no need to send another one. Use atomic swap to protect
59*0Sstevel@tonic-gate 	 * against multiple CPUs sending redundant pokes.
60*0Sstevel@tonic-gate 	 */
61*0Sstevel@tonic-gate 	if (panicstr || *ptr == B_TRUE ||
62*0Sstevel@tonic-gate 	    atomic_swap_32(ptr, B_TRUE) == B_TRUE)
63*0Sstevel@tonic-gate 		return;
64*0Sstevel@tonic-gate 
65*0Sstevel@tonic-gate 	xt_one(cpun, setsoftint_tl1, poke_cpu_inum, 0);
66*0Sstevel@tonic-gate }
67