mp_call.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Facilities for cross-processor subroutine calls using "mailbox" interrupts.
*/
#include <sys/types.h>
#include <sys/thread.h>
#include <sys/cpuvar.h>
#include <sys/x_call.h>
#include <sys/systm.h>
#include <sys/machsystm.h>
#include <sys/intr.h>
/*
* Interrupt another CPU.
* This is useful to make the other CPU go through a trap so that
* it recognizes an address space trap (AST) for preempting a thread.
*
* It is possible to be preempted here and be resumed on the CPU
* being poked, so it isn't an error to poke the current CPU.
* We could check this and still get preempted after the check, so
* we don't bother.
*/
void
poke_cpu(int cpun)
{
uint32_t *ptr = (uint32_t *)&cpu[cpun]->cpu_m.poke_cpu_outstanding;
/*
* If panicstr is set or a poke_cpu is already pending,
* no need to send another one. Use atomic swap to protect
* against multiple CPUs sending redundant pokes.
*/
if (panicstr || *ptr == B_TRUE ||
atomic_swap_32(ptr, B_TRUE) == B_TRUE)
return;
xt_one(cpun, setsoftint_tl1, poke_cpu_inum, 0);
}