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 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*
27 * Facilities for cross-processor subroutine calls using "mailbox" interrupts.
28 */
29
30#include <sys/types.h>
31#include <sys/thread.h>
32#include <sys/cpuvar.h>
33#include <sys/x_call.h>
34#include <sys/systm.h>
35#include <sys/machsystm.h>
36#include <sys/intr.h>
37#include <sys/xc_impl.h>
38
39/*
40 * Interrupt another CPU.
41 * 	This is useful to make the other CPU go through a trap so that
42 *	it recognizes an address space trap (AST) for preempting a thread.
43 *
44 *	It is possible to be preempted here and be resumed on the CPU
45 *	being poked, so it isn't an error to poke the current CPU.
46 *	We could check this and still get preempted after the check, so
47 *	we don't bother.
48 */
49void
50poke_cpu(int cpun)
51{
52	uint32_t *ptr = (uint32_t *)&cpu[cpun]->cpu_m.poke_cpu_outstanding;
53
54	/*
55	 * If panicstr is set or a poke_cpu is already pending,
56	 * no need to send another one. Use atomic swap to protect
57	 * against multiple CPUs sending redundant pokes.
58	 */
59	if (panicstr || *ptr == B_TRUE ||
60	    atomic_swap_32(ptr, B_TRUE) == B_TRUE)
61		return;
62
63	xt_one(cpun, setsoftint_tl1, poke_cpu_inum, 0);
64}
65
66extern int xc_spl_enter[];
67
68/*
69 * Call a function on a target CPU
70 */
71void
72cpu_call(cpu_t *cp, cpu_call_func_t func, uintptr_t arg1, uintptr_t arg2)
73{
74	if (panicstr)
75		return;
76
77	/*
78	 * Prevent CPU from going offline
79	 */
80	kpreempt_disable();
81
82	/*
83	 * If we are on the target CPU, call the function directly, but raise
84	 * the PIL to XC_PIL.
85	 * This guarantees that functions called via cpu_call() can not ever
86	 * interrupt each other.
87	 */
88	if (CPU != cp) {
89		xc_one(cp->cpu_id, (xcfunc_t *)func, (uint64_t)arg1,
90		    (uint64_t)arg2);
91	} else {
92		int lcx;
93		int opl;
94
95		XC_SPL_ENTER(lcx, opl);
96		func(arg1, arg2);
97		XC_SPL_EXIT(lcx, opl);
98	}
99
100	kpreempt_enable();
101}
102