initial commit
[freebsd-arm:freebsd-arm.git] / cddl / dev / dtrace / dtrace_vtime.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  * $FreeBSD$
22  */
23
24 /*
25  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28
29 void
30 dtrace_vtime_enable(void)
31 {
32         dtrace_vtime_state_t state, nstate = 0;
33
34         do {
35                 state = dtrace_vtime_active;
36
37                 switch (state) {
38                 case DTRACE_VTIME_INACTIVE:
39                         nstate = DTRACE_VTIME_ACTIVE;
40                         break;
41
42                 case DTRACE_VTIME_INACTIVE_TNF:
43                         nstate = DTRACE_VTIME_ACTIVE_TNF;
44                         break;
45
46                 case DTRACE_VTIME_ACTIVE:
47                 case DTRACE_VTIME_ACTIVE_TNF:
48                         panic("DTrace virtual time already enabled");
49                         /*NOTREACHED*/
50                 }
51
52         } while (dtrace_cas32((uint32_t *)&dtrace_vtime_active,
53             state, nstate) != state);
54 }
55
56 void
57 dtrace_vtime_disable(void)
58 {
59         dtrace_vtime_state_t state, nstate = 0;
60
61         do {
62                 state = dtrace_vtime_active;
63
64                 switch (state) {
65                 case DTRACE_VTIME_ACTIVE:
66                         nstate = DTRACE_VTIME_INACTIVE;
67                         break;
68
69                 case DTRACE_VTIME_ACTIVE_TNF:
70                         nstate = DTRACE_VTIME_INACTIVE_TNF;
71                         break;
72
73                 case DTRACE_VTIME_INACTIVE:
74                 case DTRACE_VTIME_INACTIVE_TNF:
75                         panic("DTrace virtual time already disabled");
76                         /*NOTREACHED*/
77                 }
78
79         } while (dtrace_cas32((uint32_t *)&dtrace_vtime_active,
80             state, nstate) != state);
81 }
82
83 void
84 dtrace_vtime_switch(kthread_t *next)
85 {
86         dtrace_icookie_t cookie;
87         hrtime_t ts;
88
89         cookie = dtrace_interrupt_disable();
90         ts = dtrace_gethrtime();
91
92         if (curthread->t_dtrace_start != 0) {
93                 curthread->t_dtrace_vtime += ts - curthread->t_dtrace_start;
94                 curthread->t_dtrace_start = 0;
95         }
96
97         if (next != NULL)
98                 next->t_dtrace_start = ts;
99
100         dtrace_interrupt_enable(cookie);
101 }