usr/src/uts/i86pc/os/mp_call.c

   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 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #include <sys/types.h>
  28 #include <sys/param.h>
  29 #include <sys/thread.h>
  30 #include <sys/cpuvar.h>
  31 #include <sys/machsystm.h>
  32 #include <sys/systm.h>
  33 #include <sys/promif.h>
  34 #include <sys/xc_levels.h>
  35 #include <sys/spl.h>
  36 #include <sys/bitmap.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         send_dirint(cpun, XC_CPUPOKE_PIL);
  58 }
  59
  60 /*
  61  * Call a function on a target CPU
  62  */
  63 void
  64 cpu_call(cpu_t *cp, cpu_call_func_t func, uintptr_t arg1, uintptr_t arg2)
  65 {
  66         cpuset_t set;
  67
  68         if (panicstr)
  69                 return;
  70
  71         /*
  72          * Prevent CPU from going off-line
  73          */
  74         kpreempt_disable();
  75
  76         /*
  77          * If we are on the target CPU, call the function directly, but raise
  78          * the PIL to XC_PIL.
  79          * This guarantees that functions called via cpu_call() can not ever
  80          * interrupt each other.
  81          */
  82         if (CPU == cp) {
  83                 int save_spl = splr(ipltospl(XC_HI_PIL));
  84
  85                 (*func)(arg1, arg2);
  86                 splx(save_spl);
  87         } else {
  88                 CPUSET_ONLY(set, cp->cpu_id);
  89                 xc_call((xc_arg_t)arg1, (xc_arg_t)arg2, 0, CPUSET2BV(set),
  90                     (xc_func_t)func);
  91         }
  92         kpreempt_enable();
  93 }