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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22
23 /*
24 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
25 * Use is subject to license terms.
26 */
27
28 /*
29 * Copyright (c) 2012 by Delphix. All rights reserved.
30 */
31
32 #include <sys/types.h>
33 #include <sys/bitmap.h>
34 #include <assert.h>
35 #include <strings.h>
36 #include <stdlib.h>
37
38 #include <dt_regset.h>
39 #include <dt_impl.h>
40
41 dt_regset_t *
dt_regset_create(ulong_t nregs)42 dt_regset_create(ulong_t nregs)
43 {
44 ulong_t n = BT_BITOUL(nregs);
45 dt_regset_t *drp = malloc(sizeof (dt_regset_t));
46
47 if (drp == NULL)
48 return (NULL);
49
50 drp->dr_bitmap = malloc(sizeof (ulong_t) * n);
51 drp->dr_size = nregs;
52
53 if (drp->dr_bitmap == NULL) {
54 dt_regset_destroy(drp);
55 return (NULL);
56 }
57
58 bzero(drp->dr_bitmap, sizeof (ulong_t) * n);
59 return (drp);
60 }
61
62 void
dt_regset_destroy(dt_regset_t * drp)63 dt_regset_destroy(dt_regset_t *drp)
64 {
65 free(drp->dr_bitmap);
66 free(drp);
67 }
68
69 void
dt_regset_reset(dt_regset_t * drp)70 dt_regset_reset(dt_regset_t *drp)
71 {
72 bzero(drp->dr_bitmap, sizeof (ulong_t) * BT_BITOUL(drp->dr_size));
73 }
74
75 void
dt_regset_assert_free(dt_regset_t * drp)76 dt_regset_assert_free(dt_regset_t *drp)
77 {
78 int reg;
79 boolean_t fail = B_FALSE;
80 for (reg = 0; reg < drp->dr_size; reg++) {
81 if (BT_TEST(drp->dr_bitmap, reg) != 0) {
82 dt_dprintf("%%r%d was left allocated\n", reg);
83 fail = B_TRUE;
84 }
85 }
86
87 /*
88 * We set this during dtest runs to check for register leaks.
89 */
90 if (fail && getenv("DTRACE_DEBUG_REGSET") != NULL)
91 abort();
92 }
93
94 int
dt_regset_alloc(dt_regset_t * drp)95 dt_regset_alloc(dt_regset_t *drp)
96 {
97 ulong_t nbits = drp->dr_size - 1;
98 ulong_t maxw = nbits >> BT_ULSHIFT;
99 ulong_t wx;
100
101 for (wx = 0; wx <= maxw; wx++) {
102 if (drp->dr_bitmap[wx] != ~0UL)
103 break;
104 }
105
106 if (wx <= maxw) {
107 ulong_t maxb = (wx == maxw) ? nbits & BT_ULMASK : BT_NBIPUL - 1;
108 ulong_t word = drp->dr_bitmap[wx];
109 ulong_t bit, bx;
110 int reg;
111
112 for (bit = 1, bx = 0; bx <= maxb; bx++, bit <<= 1) {
113 if ((word & bit) == 0) {
114 reg = (int)((wx << BT_ULSHIFT) | bx);
115 BT_SET(drp->dr_bitmap, reg);
116 return (reg);
117 }
118 }
119 }
120
121 xyerror(D_NOREG, "Insufficient registers to generate code");
122 /*NOTREACHED*/
123 return (-1);
124 }
125
126 void
dt_regset_free(dt_regset_t * drp,int reg)127 dt_regset_free(dt_regset_t *drp, int reg)
128 {
129 assert(reg >= 0 && reg < drp->dr_size);
130 assert(BT_TEST(drp->dr_bitmap, reg) != 0);
131 BT_CLEAR(drp->dr_bitmap, reg);
132 }
133