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 * Copyright (c) 2016 Pedro Giffuni. All rights reserved.
31 */
32
33 #include <sys/types.h>
34 #include <sys/bitmap.h>
35 #include <assert.h>
36 #include <strings.h>
37 #include <stdlib.h>
38
39 #include <dt_regset.h>
40 #include <dt_impl.h>
41
42 dt_regset_t *
dt_regset_create(ulong_t nregs)43 dt_regset_create(ulong_t nregs)
44 {
45 ulong_t n = BT_BITOUL(nregs);
46 dt_regset_t *drp = malloc(sizeof (dt_regset_t));
47
48 if (drp == NULL)
49 return (NULL);
50
51 drp->dr_bitmap = calloc(n, sizeof (ulong_t));
52
53 if (drp->dr_bitmap == NULL) {
54 dt_regset_destroy(drp);
55 return (NULL);
56 }
57
58 drp->dr_size = nregs;
59
60 return (drp);
61 }
62
63 void
dt_regset_destroy(dt_regset_t * drp)64 dt_regset_destroy(dt_regset_t *drp)
65 {
66 free(drp->dr_bitmap);
67 free(drp);
68 }
69
70 void
dt_regset_reset(dt_regset_t * drp)71 dt_regset_reset(dt_regset_t *drp)
72 {
73 bzero(drp->dr_bitmap, sizeof (ulong_t) * BT_BITOUL(drp->dr_size));
74 }
75
76 void
dt_regset_assert_free(dt_regset_t * drp)77 dt_regset_assert_free(dt_regset_t *drp)
78 {
79 int reg;
80 boolean_t fail = B_FALSE;
81 for (reg = 0; reg < drp->dr_size; reg++) {
82 if (BT_TEST(drp->dr_bitmap, reg) != 0) {
83 dt_dprintf("%%r%d was left allocated\n", reg);
84 fail = B_TRUE;
85 }
86 }
87
88 /*
89 * We set this during dtest runs to check for register leaks.
90 */
91 if (fail && getenv("DTRACE_DEBUG_REGSET") != NULL)
92 abort();
93 }
94
95 int
dt_regset_alloc(dt_regset_t * drp)96 dt_regset_alloc(dt_regset_t *drp)
97 {
98 ulong_t nbits = drp->dr_size - 1;
99 ulong_t maxw = nbits >> BT_ULSHIFT;
100 ulong_t wx;
101
102 for (wx = 0; wx <= maxw; wx++) {
103 if (drp->dr_bitmap[wx] != ~0UL)
104 break;
105 }
106
107 if (wx <= maxw) {
108 ulong_t maxb = (wx == maxw) ? nbits & BT_ULMASK : BT_NBIPUL - 1;
109 ulong_t word = drp->dr_bitmap[wx];
110 ulong_t bit, bx;
111 int reg;
112
113 for (bit = 1, bx = 0; bx <= maxb; bx++, bit <<= 1) {
114 if ((word & bit) == 0) {
115 reg = (int)((wx << BT_ULSHIFT) | bx);
116 BT_SET(drp->dr_bitmap, reg);
117 return (reg);
118 }
119 }
120 }
121
122 xyerror(D_NOREG, "Insufficient registers to generate code");
123 /*NOTREACHED*/
124 return (-1);
125 }
126
127 void
dt_regset_free(dt_regset_t * drp,int reg)128 dt_regset_free(dt_regset_t *drp, int reg)
129 {
130 assert(reg >= 0 && reg < drp->dr_size);
131 assert(BT_TEST(drp->dr_bitmap, reg) != 0);
132 BT_CLEAR(drp->dr_bitmap, reg);
133 }
134