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