xref: /onnv-gate/usr/src/lib/libdtrace/common/dt_regset.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #include <sys/types.h>
30*0Sstevel@tonic-gate #include <sys/bitmap.h>
31*0Sstevel@tonic-gate #include <assert.h>
32*0Sstevel@tonic-gate #include <strings.h>
33*0Sstevel@tonic-gate #include <stdlib.h>
34*0Sstevel@tonic-gate 
35*0Sstevel@tonic-gate #include <dt_regset.h>
36*0Sstevel@tonic-gate 
37*0Sstevel@tonic-gate dt_regset_t *
dt_regset_create(ulong_t size)38*0Sstevel@tonic-gate dt_regset_create(ulong_t size)
39*0Sstevel@tonic-gate {
40*0Sstevel@tonic-gate 	ulong_t n = BT_BITOUL(size + 1); /* + 1 for %r0 */
41*0Sstevel@tonic-gate 	dt_regset_t *drp = malloc(sizeof (dt_regset_t));
42*0Sstevel@tonic-gate 
43*0Sstevel@tonic-gate 	if (drp == NULL)
44*0Sstevel@tonic-gate 		return (NULL);
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate 	drp->dr_bitmap = malloc(sizeof (ulong_t) * n);
47*0Sstevel@tonic-gate 	drp->dr_size = size + 1;
48*0Sstevel@tonic-gate 
49*0Sstevel@tonic-gate 	if (drp->dr_bitmap == NULL) {
50*0Sstevel@tonic-gate 		dt_regset_destroy(drp);
51*0Sstevel@tonic-gate 		return (NULL);
52*0Sstevel@tonic-gate 	}
53*0Sstevel@tonic-gate 
54*0Sstevel@tonic-gate 	bzero(drp->dr_bitmap, sizeof (ulong_t) * n);
55*0Sstevel@tonic-gate 	return (drp);
56*0Sstevel@tonic-gate }
57*0Sstevel@tonic-gate 
58*0Sstevel@tonic-gate void
dt_regset_destroy(dt_regset_t * drp)59*0Sstevel@tonic-gate dt_regset_destroy(dt_regset_t *drp)
60*0Sstevel@tonic-gate {
61*0Sstevel@tonic-gate 	free(drp->dr_bitmap);
62*0Sstevel@tonic-gate 	free(drp);
63*0Sstevel@tonic-gate }
64*0Sstevel@tonic-gate 
65*0Sstevel@tonic-gate void
dt_regset_reset(dt_regset_t * drp)66*0Sstevel@tonic-gate dt_regset_reset(dt_regset_t *drp)
67*0Sstevel@tonic-gate {
68*0Sstevel@tonic-gate 	bzero(drp->dr_bitmap, sizeof (ulong_t) * BT_BITOUL(drp->dr_size));
69*0Sstevel@tonic-gate }
70*0Sstevel@tonic-gate 
71*0Sstevel@tonic-gate int
dt_regset_alloc(dt_regset_t * drp)72*0Sstevel@tonic-gate dt_regset_alloc(dt_regset_t *drp)
73*0Sstevel@tonic-gate {
74*0Sstevel@tonic-gate 	ulong_t nbits = drp->dr_size - 1;
75*0Sstevel@tonic-gate 	ulong_t maxw = nbits >> BT_ULSHIFT;
76*0Sstevel@tonic-gate 	ulong_t wx;
77*0Sstevel@tonic-gate 
78*0Sstevel@tonic-gate 	for (wx = 0; wx <= maxw; wx++) {
79*0Sstevel@tonic-gate 		if (drp->dr_bitmap[wx] != ~0UL)
80*0Sstevel@tonic-gate 			break;
81*0Sstevel@tonic-gate 	}
82*0Sstevel@tonic-gate 
83*0Sstevel@tonic-gate 	if (wx <= maxw) {
84*0Sstevel@tonic-gate 		ulong_t maxb = (wx == maxw) ? nbits & BT_ULMASK : BT_NBIPUL - 1;
85*0Sstevel@tonic-gate 		ulong_t word = drp->dr_bitmap[wx];
86*0Sstevel@tonic-gate 		ulong_t bit, bx;
87*0Sstevel@tonic-gate 		int reg;
88*0Sstevel@tonic-gate 
89*0Sstevel@tonic-gate 		for (bit = 1, bx = 0; bx <= maxb; bx++, bit <<= 1) {
90*0Sstevel@tonic-gate 			if ((word & bit) == 0) {
91*0Sstevel@tonic-gate 				reg = (int)((wx << BT_ULSHIFT) | bx);
92*0Sstevel@tonic-gate 				BT_SET(drp->dr_bitmap, reg);
93*0Sstevel@tonic-gate 				return (reg);
94*0Sstevel@tonic-gate 			}
95*0Sstevel@tonic-gate 		}
96*0Sstevel@tonic-gate 	}
97*0Sstevel@tonic-gate 
98*0Sstevel@tonic-gate 	return (-1); /* no available registers */
99*0Sstevel@tonic-gate }
100*0Sstevel@tonic-gate 
101*0Sstevel@tonic-gate void
dt_regset_free(dt_regset_t * drp,int reg)102*0Sstevel@tonic-gate dt_regset_free(dt_regset_t *drp, int reg)
103*0Sstevel@tonic-gate {
104*0Sstevel@tonic-gate 	assert(reg > 0 && reg < drp->dr_size);
105*0Sstevel@tonic-gate 	assert(BT_TEST(drp->dr_bitmap, reg) != 0);
106*0Sstevel@tonic-gate 	BT_CLEAR(drp->dr_bitmap, reg);
107*0Sstevel@tonic-gate }
108