xref: /illumos-gate/usr/src/uts/common/io/usb/clients/usbser/usbser_rseq.c (revision 355b4669e025ff377602b6fc7caaf30dbc218371)
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  * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * rseq implementation
31  */
32 
33 #include <sys/usb/clients/usbser/usbser_rseq.h>
34 
35 #ifdef _KERNEL
36 #include <sys/debug.h>
37 #include <sys/ddi.h>
38 #include <sys/sunddi.h>
39 static long rseq_random();
40 #define	random	rseq_random
41 #else
42 #include <assert.h>
43 #define	ASSERT	assert
44 #include <stdlib.h>
45 #endif
46 
47 
48 /*ARGSUSED*/
49 static int
50 rseq_do_common(rseq_t *rseq, int num, uintptr_t arg, int flags, int fail_err,
51 		uintptr_t fail_num)
52 {
53 	int		i;
54 	rseq_step_t	*s;
55 	int		rval = RSEQ_OK;
56 
57 	for (i = 0; i < num; i++) {
58 		s = &rseq[i].r_do;
59 
60 		if (s->s_func == NULL) {
61 			continue;
62 		}
63 		s->s_rval = (i != fail_num) ? s->s_func(arg) : fail_err;
64 		rval = (s->s_cb) ? (s->s_cb(rseq, i, arg)) : RSEQ_OK;
65 
66 		if (rval == RSEQ_UNDO) {
67 			(void) rseq_undo(rseq, i, arg, flags);
68 			break;
69 		} else if (rval == RSEQ_ABORT) {
70 			break;
71 		}
72 		ASSERT(rval == RSEQ_OK);
73 	}
74 	return (rval);
75 }
76 
77 
78 /*ARGSUSED*/
79 static int
80 rseq_undo_common(rseq_t *rseq, int num, uintptr_t arg, int flags, int fail_err,
81 		uintptr_t fail_num)
82 {
83 	int		i;
84 	rseq_step_t	*s;
85 	int		rval = RSEQ_OK;
86 
87 	for (i = num - 1; i >= 0; i--) {
88 		s = &rseq[i].r_undo;
89 
90 		if (s->s_func == NULL) {
91 			continue;
92 		}
93 		s->s_rval = (i != fail_num) ? s->s_func(arg) : fail_err;
94 		rval = (s->s_cb) ? (s->s_cb(rseq, i, arg)) : RSEQ_OK;
95 
96 		if (rval == RSEQ_ABORT) {
97 			break;
98 		}
99 		ASSERT(rval == RSEQ_OK);
100 	}
101 	return (rval);
102 }
103 
104 
105 int
106 rseq_do(rseq_t *rseq, int num, uintptr_t arg, int flags)
107 {
108 	return (rseq_do_common(rseq, num, arg, flags, 0, -1));
109 }
110 
111 
112 int
113 rseq_undo(rseq_t *rseq, int num, uintptr_t arg, int flags)
114 {
115 	return (rseq_undo_common(rseq, num, arg, flags, 0, -1));
116 }
117 
118 #ifdef DEBUG
119 
120 #ifndef __lock_lint
121 
122 static int
123 rseq_debug(rseq_t *rseq, int num, uintptr_t arg, int flags, int scenario,
124 		uintptr_t sarg1, uintptr_t sarg2,
125 		int (*func)(rseq_t *, int, uintptr_t, int, int, uintptr_t))
126 {
127 	int	rnd, rval, i;
128 
129 	switch (scenario) {
130 	case RSEQ_DBG_FAIL_ONE:
131 		rval = func(rseq, num, arg, flags, sarg1, sarg2);
132 		break;
133 	case RSEQ_DBG_FAIL_ONE_RANDOM:
134 		rnd = random() % num;
135 		rval = func(rseq, num, arg, flags, sarg1, rnd);
136 		break;
137 	case RSEQ_DBG_FAIL_ONEBYONE:
138 		for (i = 0; i < num; i++) {
139 			rval = func(rseq, num, arg, flags, sarg1, i);
140 			/*
141 			 * when aborted, the undo path is not executed, so we
142 			 * can't continue without the risk of resource leakage.
143 			 */
144 			if (rval == RSEQ_ABORT) {
145 				break;
146 			}
147 		}
148 		break;
149 	default:
150 		ASSERT(!"rseq_debug: incorrect debug scenario");
151 	}
152 	return (rval);
153 }
154 
155 
156 int
157 rseq_do_debug(rseq_t *rseq, int num, uintptr_t arg, int flags, int scenario,
158 		uintptr_t sarg1, uintptr_t sarg2)
159 {
160 	return (rseq_debug(rseq, num, arg, flags, scenario, sarg1, sarg2,
161 			rseq_do_common));
162 }
163 
164 
165 int
166 rseq_undo_debug(rseq_t *rseq, int num, uintptr_t arg, int flags, int scenario,
167 		uintptr_t sarg1, uintptr_t sarg2)
168 {
169 	return (rseq_debug(rseq, num, arg, flags, scenario, sarg1, sarg2,
170 			rseq_undo_common));
171 }
172 
173 #ifdef _KERNEL
174 static long
175 rseq_random()
176 {
177 	return (ddi_get_lbolt());
178 }
179 #endif /* _KERNEL */
180 
181 #endif /* __lock_lint */
182 
183 #endif /* DEBUG */
184