xref: /illumos-gate/usr/src/uts/i86pc/os/mp_call.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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)(uintptr_t)func);
91 	}
92 	kpreempt_enable();
93 }
94