xref: /freebsd/sys/cddl/dev/dtrace/dtrace_vtime.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 }
102