1 /* $NetBSD: kern_kthread.c,v 1.21 2008/02/14 14:26:57 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 1999, 2007 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 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 __KERNEL_RCSID(0, "$NetBSD: kern_kthread.c,v 1.21 2008/02/14 14:26:57 ad Exp $"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/kthread.h> 47 #include <sys/proc.h> 48 #include <sys/sched.h> 49 #include <sys/kmem.h> 50 51 #include <uvm/uvm_extern.h> 52 53 /* 54 * note that stdarg.h and the ansi style va_start macro is used for both 55 * ansi and traditional c complers. 56 * XXX: this requires that stdarg.h define: va_alist and va_dcl 57 */ 58 #include <machine/stdarg.h> 59 60 /* 61 * Fork a kernel thread. Any process can request this to be done. 62 */ 63 int 64 kthread_create(pri_t pri, int flag, struct cpu_info *ci, 65 void (*func)(void *), void *arg, 66 lwp_t **lp, const char *fmt, ...) 67 { 68 lwp_t *l; 69 vaddr_t uaddr; 70 bool inmem; 71 int error; 72 va_list ap; 73 74 inmem = uvm_uarea_alloc(&uaddr); 75 if (uaddr == 0) 76 return ENOMEM; 77 error = lwp_create(&lwp0, &proc0, uaddr, inmem, LWP_DETACHED, NULL, 78 0, func, arg, &l, SCHED_FIFO); 79 if (error) { 80 uvm_uarea_free(uaddr, curcpu()); 81 return error; 82 } 83 uvm_lwp_hold(l); 84 if (fmt != NULL) { 85 l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP); 86 if (l->l_name == NULL) { 87 lwp_exit(l); 88 return ENOMEM; 89 } 90 va_start(ap, fmt); 91 vsnprintf(l->l_name, MAXCOMLEN, fmt, ap); 92 va_end(ap); 93 } 94 95 /* 96 * Set parameters. 97 */ 98 if ((flag & KTHREAD_INTR) != 0) { 99 KASSERT((flag & KTHREAD_MPSAFE) != 0); 100 } 101 102 if (pri == PRI_NONE) { 103 /* Minimum kernel priority level. */ 104 pri = PRI_KTHREAD; 105 } 106 mutex_enter(&proc0.p_smutex); 107 lwp_lock(l); 108 l->l_priority = pri; 109 if (ci != NULL) { 110 if (ci != l->l_cpu) { 111 lwp_unlock_to(l, ci->ci_schedstate.spc_mutex); 112 lwp_lock(l); 113 } 114 l->l_flag |= LW_BOUND; 115 l->l_cpu = ci; 116 } 117 if ((flag & KTHREAD_INTR) != 0) 118 l->l_pflag |= LP_INTR; 119 if ((flag & KTHREAD_MPSAFE) == 0) 120 l->l_pflag &= ~LP_MPSAFE; 121 122 /* 123 * Set the new LWP running, unless the caller has requested 124 * otherwise. 125 */ 126 if ((flag & KTHREAD_IDLE) == 0) { 127 l->l_stat = LSRUN; 128 sched_enqueue(l, false); 129 lwp_unlock(l); 130 } else 131 lwp_unlock_to(l, ci->ci_schedstate.spc_lwplock); 132 133 /* 134 * The LWP is not created suspended or stopped and cannot be set 135 * into those states later, so must be considered runnable. 136 */ 137 proc0.p_nrlwps++; 138 mutex_exit(&proc0.p_smutex); 139 140 /* All done! */ 141 if (lp != NULL) 142 *lp = l; 143 144 return (0); 145 } 146 147 /* 148 * Cause a kernel thread to exit. Assumes the exiting thread is the 149 * current context. 150 */ 151 void 152 kthread_exit(int ecode) 153 { 154 const char *name; 155 lwp_t *l = curlwp; 156 157 /* We can't do much with the exit code, so just report it. */ 158 if (ecode != 0) { 159 if ((name = l->l_name) == NULL) 160 name = "unnamed"; 161 printf("WARNING: kthread `%s' (%d) exits with status %d\n", 162 name, l->l_lid, ecode); 163 } 164 165 /* And exit.. */ 166 lwp_exit(l); 167 168 /* 169 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 170 * XXX of worms right now. 171 */ 172 for (;;) 173 ; 174 } 175 176 /* 177 * Destroy an inactive kthread. The kthread must be in the LSIDL state. 178 */ 179 void 180 kthread_destroy(lwp_t *l) 181 { 182 183 KASSERT((l->l_flag & LW_SYSTEM) != 0); 184 KASSERT(l->l_stat == LSIDL); 185 186 lwp_exit(l); 187 } 188