1 /* $NetBSD: kern_kthread.c,v 1.26 2009/01/30 04:09:35 agc Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 1999, 2007, 2009 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center, and by Andrew Doran. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: kern_kthread.c,v 1.26 2009/01/30 04:09:35 agc Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/proc.h> 41 #include <sys/sched.h> 42 #include <sys/kmem.h> 43 44 #include <uvm/uvm_extern.h> 45 46 /* 47 * note that stdarg.h and the ansi style va_start macro is used for both 48 * ansi and traditional c complers. 49 * XXX: this requires that stdarg.h define: va_alist and va_dcl 50 */ 51 #include <machine/stdarg.h> 52 53 /* 54 * Fork a kernel thread. Any process can request this to be done. 55 */ 56 int 57 kthread_create(pri_t pri, int flag, struct cpu_info *ci, 58 void (*func)(void *), void *arg, 59 lwp_t **lp, const char *fmt, ...) 60 { 61 lwp_t *l; 62 vaddr_t uaddr; 63 bool inmem; 64 int error; 65 va_list ap; 66 int lc; 67 68 inmem = uvm_uarea_alloc(&uaddr); 69 if (uaddr == 0) 70 return ENOMEM; 71 if ((flag & KTHREAD_TS) != 0) { 72 lc = SCHED_OTHER; 73 } else { 74 lc = SCHED_RR; 75 } 76 error = lwp_create(&lwp0, &proc0, uaddr, inmem, LWP_DETACHED, NULL, 77 0, func, arg, &l, lc); 78 if (error) { 79 uvm_uarea_free(uaddr, curcpu()); 80 return error; 81 } 82 uvm_lwp_hold(l); 83 if (fmt != NULL) { 84 l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP); 85 if (l->l_name == NULL) { 86 lwp_exit(l); 87 return ENOMEM; 88 } 89 va_start(ap, fmt); 90 vsnprintf(l->l_name, MAXCOMLEN, fmt, ap); 91 va_end(ap); 92 } 93 94 /* 95 * Set parameters. 96 */ 97 if ((flag & KTHREAD_INTR) != 0) { 98 KASSERT((flag & KTHREAD_MPSAFE) != 0); 99 } 100 101 if (pri == PRI_NONE) { 102 if ((flag & KTHREAD_TS) != 0) { 103 /* Maximum user priority level. */ 104 pri = MAXPRI_USER; 105 } else { 106 /* Minimum kernel priority level. */ 107 pri = PRI_KTHREAD; 108 } 109 } 110 mutex_enter(proc0.p_lock); 111 lwp_lock(l); 112 l->l_priority = pri; 113 if (ci != NULL) { 114 if (ci != l->l_cpu) { 115 lwp_unlock_to(l, ci->ci_schedstate.spc_mutex); 116 lwp_lock(l); 117 } 118 l->l_pflag |= LP_BOUND; 119 l->l_cpu = ci; 120 } 121 if ((flag & KTHREAD_INTR) != 0) 122 l->l_pflag |= LP_INTR; 123 if ((flag & KTHREAD_MPSAFE) == 0) 124 l->l_pflag &= ~LP_MPSAFE; 125 126 /* 127 * Set the new LWP running, unless the caller has requested 128 * otherwise. 129 */ 130 if ((flag & KTHREAD_IDLE) == 0) { 131 l->l_stat = LSRUN; 132 sched_enqueue(l, false); 133 lwp_unlock(l); 134 } else 135 lwp_unlock_to(l, ci->ci_schedstate.spc_lwplock); 136 137 /* 138 * The LWP is not created suspended or stopped and cannot be set 139 * into those states later, so must be considered runnable. 140 */ 141 proc0.p_nrlwps++; 142 mutex_exit(proc0.p_lock); 143 144 /* All done! */ 145 if (lp != NULL) 146 *lp = l; 147 148 return (0); 149 } 150 151 /* 152 * Cause a kernel thread to exit. Assumes the exiting thread is the 153 * current context. 154 */ 155 void 156 kthread_exit(int ecode) 157 { 158 const char *name; 159 lwp_t *l = curlwp; 160 161 /* We can't do much with the exit code, so just report it. */ 162 if (ecode != 0) { 163 if ((name = l->l_name) == NULL) 164 name = "unnamed"; 165 printf("WARNING: kthread `%s' (%d) exits with status %d\n", 166 name, l->l_lid, ecode); 167 } 168 169 /* And exit.. */ 170 lwp_exit(l); 171 172 /* 173 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 174 * XXX of worms right now. 175 */ 176 for (;;) 177 ; 178 } 179 180 /* 181 * Destroy an inactive kthread. The kthread must be in the LSIDL state. 182 */ 183 void 184 kthread_destroy(lwp_t *l) 185 { 186 187 KASSERT((l->l_flag & LW_SYSTEM) != 0); 188 KASSERT(l->l_stat == LSIDL); 189 190 lwp_exit(l); 191 } 192