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threads.c revision 1.9 
      1 /*	$NetBSD: threads.c,v 1.9 2010/05/28 16:44:14 pooka 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 1.9 2010/05/28 16:44:14 pooka Exp $");
     33 
     34 #include <sys/param.h>
     35 #include <sys/kmem.h>
     36 #include <sys/kthread.h>
     37 #include <sys/systm.h>
     38 
     39 #include <machine/stdarg.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 	rumpuser_free(k);
     62 
     63 	/* schedule ourselves */
     64 	rumpuser_set_curlwp(l);
     65 	rump_schedule();
     66 
     67 	if ((curlwp->l_pflag & LP_MPSAFE) == 0)
     68 		KERNEL_LOCK(1, NULL);
     69 
     70 	f(thrarg);
     71 
     72 	panic("unreachable, should kthread_exit()");
     73 }
     74 
     75 int
     76 kthread_create(pri_t pri, int flags, struct cpu_info *ci,
     77 	void (*func)(void *), void *arg, lwp_t **newlp, const char *fmt, ...)
     78 {
     79 	char thrstore[MAXCOMLEN];
     80 	const char *thrname = NULL;
     81 	va_list ap;
     82 	struct kthdesc *k;
     83 	struct lwp *l;
     84 	int rv;
     85 
     86 	thrstore[0] = '\0';
     87 	if (fmt) {
     88 		va_start(ap, fmt);
     89 		vsnprintf(thrstore, sizeof(thrstore), fmt, ap);
     90 		va_end(ap);
     91 		thrname = thrstore;
     92 	}
     93 
     94 	/*
     95 	 * We don't want a module unload thread.
     96 	 * (XXX: yes, this is a kludge too, and the kernel should
     97 	 * have a more flexible method for configuring which threads
     98 	 * we want).
     99 	 */
    100 	if (strcmp(thrstore, "modunload") == 0) {
    101 		return 0;
    102 	}
    103 
    104 	if (!rump_threads) {
    105 		/* fake them */
    106 		if (strcmp(thrstore, "vrele") == 0) {
    107 			printf("rump warning: threads not enabled, not starting"
    108 			   " vrele thread\n");
    109 			return 0;
    110 		} else if (strcmp(thrstore, "cachegc") == 0) {
    111 			printf("rump warning: threads not enabled, not starting"
    112 			   " namecache g/c thread\n");
    113 			return 0;
    114 		} else if (strcmp(thrstore, "nfssilly") == 0) {
    115 			printf("rump warning: threads not enabled, not enabling"
    116 			   " nfs silly rename\n");
    117 			return 0;
    118 		} else if (strcmp(thrstore, "unpgc") == 0) {
    119 			printf("rump warning: threads not enabled, not enabling"
    120 			   " UNP garbage collection\n");
    121 			return 0;
    122 		} else if (strncmp(thrstore, "pmf", sizeof("pmf")-1) == 0) {
    123 			printf("rump warning: threads not enabled, not enabling"
    124 			   " pmf thread\n");
    125 			return 0;
    126 		} else if (strncmp(thrstore, "xcall", sizeof("xcall")-1) == 0) {
    127 			printf("rump warning: threads not enabled, CPU xcall"
    128 			   " not functional\n");
    129 			return 0;
    130 		} else
    131 			panic("threads not available, setenv RUMP_THREADS 1");
    132 	}
    133 	KASSERT(fmt != NULL);
    134 
    135 	k = rumpuser_malloc(sizeof(struct kthdesc), 0);
    136 	k->f = func;
    137 	k->arg = arg;
    138 	k->mylwp = l = rump_lwp_alloc(0, rump_nextlid());
    139 	l->l_flag |= LW_SYSTEM;
    140 	if (flags & KTHREAD_MPSAFE)
    141 		l->l_pflag |= LP_MPSAFE;
    142 	if (flags & KTHREAD_INTR)
    143 		l->l_pflag |= LP_INTR;
    144 	if (ci) {
    145 		l->l_pflag |= LP_BOUND;
    146 		l->l_target_cpu = ci;
    147 	}
    148 	if (thrname) {
    149 		l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP);
    150 		strlcpy(l->l_name, thrname, MAXCOMLEN);
    151 	}
    152 
    153 	rv = rumpuser_thread_create(threadbouncer, k, thrname);
    154 	if (rv)
    155 		return rv;
    156 
    157 	if (newlp)
    158 		*newlp = l;
    159 	return 0;
    160 }
    161 
    162 void
    163 kthread_exit(int ecode)
    164 {
    165 
    166 	if ((curlwp->l_pflag & LP_MPSAFE) == 0)
    167 		KERNEL_UNLOCK_LAST(NULL);
    168 	rump_lwp_release(curlwp);
    169 	rump_unschedule();
    170 	rumpuser_thread_exit();
    171 }
    172