xref: /netbsd-src/sys/rump/librump/rumpkern/threads.c (revision 9ddb6ab554e70fb9bbd90c3d96b812bc57755a14)
1 /*	$NetBSD: threads.c,v 1.15 2011/08/07 14:03:16 rmind Exp $	*/
2 
3 /*
4  * Copyright (c) 2007-2009 Antti Kantee.  All Rights Reserved.
5  *
6  * Development of this software was supported by
7  * The Finnish Cultural Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: threads.c,v 1.15 2011/08/07 14:03:16 rmind Exp $");
33 
34 #include <sys/param.h>
35 #include <sys/atomic.h>
36 #include <sys/kmem.h>
37 #include <sys/kthread.h>
38 #include <sys/malloc.h>
39 #include <sys/systm.h>
40 
41 #include <rump/rumpuser.h>
42 
43 #include "rump_private.h"
44 
45 struct kthdesc {
46 	void (*f)(void *);
47 	void *arg;
48 	struct lwp *mylwp;
49 };
50 
51 static void *
52 threadbouncer(void *arg)
53 {
54 	struct kthdesc *k = arg;
55 	struct lwp *l = k->mylwp;
56 	void (*f)(void *);
57 	void *thrarg;
58 
59 	f = k->f;
60 	thrarg = k->arg;
61 
62 	/* schedule ourselves */
63 	rumpuser_set_curlwp(l);
64 	rump_schedule();
65 
66 	/* free dance struct */
67 	free(k, M_TEMP);
68 
69 	if ((curlwp->l_pflag & LP_MPSAFE) == 0)
70 		KERNEL_LOCK(1, NULL);
71 
72 	f(thrarg);
73 
74 	panic("unreachable, should kthread_exit()");
75 }
76 
77 int
78 kthread_create(pri_t pri, int flags, struct cpu_info *ci,
79 	void (*func)(void *), void *arg, lwp_t **newlp, const char *fmt, ...)
80 {
81 	char thrstore[MAXCOMLEN];
82 	const char *thrname = NULL;
83 	va_list ap;
84 	struct kthdesc *k;
85 	struct lwp *l;
86 	int rv;
87 
88 	thrstore[0] = '\0';
89 	if (fmt) {
90 		va_start(ap, fmt);
91 		vsnprintf(thrstore, sizeof(thrstore), fmt, ap);
92 		va_end(ap);
93 		thrname = thrstore;
94 	}
95 
96 	/*
97 	 * We don't want a module unload thread.
98 	 * (XXX: yes, this is a kludge too, and the kernel should
99 	 * have a more flexible method for configuring which threads
100 	 * we want).
101 	 */
102 	if (strcmp(thrstore, "modunload") == 0) {
103 		return 0;
104 	}
105 
106 	if (!rump_threads) {
107 		/* fake them */
108 		if (strcmp(thrstore, "vrele") == 0) {
109 			printf("rump warning: threads not enabled, not starting"
110 			   " vrele thread\n");
111 			return 0;
112 		} else if (strcmp(thrstore, "cachegc") == 0) {
113 			printf("rump warning: threads not enabled, not starting"
114 			   " namecache g/c thread\n");
115 			return 0;
116 		} else if (strcmp(thrstore, "nfssilly") == 0) {
117 			printf("rump warning: threads not enabled, not enabling"
118 			   " nfs silly rename\n");
119 			return 0;
120 		} else if (strcmp(thrstore, "unpgc") == 0) {
121 			printf("rump warning: threads not enabled, not enabling"
122 			   " UNP garbage collection\n");
123 			return 0;
124 		} else if (strncmp(thrstore, "pmf", sizeof("pmf")-1) == 0) {
125 			printf("rump warning: threads not enabled, not enabling"
126 			   " pmf thread\n");
127 			return 0;
128 		} else if (strncmp(thrstore, "xcall", sizeof("xcall")-1) == 0) {
129 			printf("rump warning: threads not enabled, CPU xcall"
130 			   " not functional\n");
131 			return 0;
132 		} else
133 			panic("threads not available, setenv RUMP_THREADS 1");
134 	}
135 	KASSERT(fmt != NULL);
136 
137 	k = malloc(sizeof(*k), M_TEMP, M_WAITOK);
138 	k->f = func;
139 	k->arg = arg;
140 	k->mylwp = l = rump__lwproc_alloclwp(&proc0);
141 	l->l_flag |= LW_SYSTEM;
142 	if (flags & KTHREAD_MPSAFE)
143 		l->l_pflag |= LP_MPSAFE;
144 	if (flags & KTHREAD_INTR)
145 		l->l_pflag |= LP_INTR;
146 	if (ci) {
147 		l->l_pflag |= LP_BOUND;
148 		l->l_target_cpu = ci;
149 	}
150 	if (thrname) {
151 		l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP);
152 		strlcpy(l->l_name, thrname, MAXCOMLEN);
153 	}
154 
155 	rv = rumpuser_thread_create(threadbouncer, k, thrname,
156 	    (flags & KTHREAD_MUSTJOIN) == KTHREAD_MUSTJOIN, &l->l_ctxlink);
157 	if (rv)
158 		return rv;
159 
160 	if (newlp) {
161 		*newlp = l;
162 	} else {
163 		KASSERT((flags & KTHREAD_MUSTJOIN) == 0);
164 	}
165 
166 	return 0;
167 }
168 
169 void
170 kthread_exit(int ecode)
171 {
172 
173 	if ((curlwp->l_pflag & LP_MPSAFE) == 0)
174 		KERNEL_UNLOCK_LAST(NULL);
175 	rump_lwproc_releaselwp();
176 	/* unschedule includes membar */
177 	rump_unschedule();
178 	rumpuser_thread_exit();
179 }
180 
181 int
182 kthread_join(struct lwp *l)
183 {
184 	int rv;
185 
186 	KASSERT(l->l_ctxlink != NULL);
187 	rv = rumpuser_thread_join(l->l_ctxlink);
188 	membar_consumer();
189 
190 	return rv;
191 }
192