/* $NetBSD: ast.c,v 1.15 2008/07/22 07:07:23 matt Exp $ */ /* * Copyright (c) 1994,1995 Mark Brinicombe * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the RiscBSD team. * 4. The name of the company nor the name of the author may be used to * endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTERS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * RiscBSD kernel project * * ast.c * * Code to handle ast's and returns to user mode * * Created : 11/10/94 */ #include <sys/cdefs.h> __KERNEL_RCSID(0, "$NetBSD: ast.c,v 1.15 2008/07/22 07:07:23 matt Exp $"); #include "opt_ddb.h" #include <sys/param.h> #include <sys/proc.h> #include <sys/user.h> #include <sys/acct.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/signal.h> #include <sys/vmmeter.h> #include <sys/userret.h> #include <machine/cpu.h> #include <machine/frame.h> #include <arm/cpufunc.h> #include <uvm/uvm_extern.h> #ifdef acorn26 #include <machine/machdep.h> #endif /* * Prototypes */ void ast(struct trapframe *); void userret(struct lwp *l) { /* Invoke MI userret code */ mi_userret(l); } /* * Handle asynchronous system traps. * This is called from the irq handler to deliver signals * and switch processes if required. */ void ast(struct trapframe *tf) { struct lwp *l = curlwp; struct proc *p; #ifdef acorn26 /* Enable interrupts if they were enabled before the trap. */ if ((tf->tf_r15 & R15_IRQ_DISABLE) == 0) int_on(); #else /* Interrupts were restored by exception_exit. */ #endif uvmexp.traps++; uvmexp.softs++; #ifdef DEBUG if (l == NULL) panic("ast: no curlwp!"); if (&l->l_addr->u_pcb == NULL) panic("ast: no pcb!"); #endif p = l->l_proc; if (l->l_pflag & LP_OWEUPC) { l->l_pflag &= ~LP_OWEUPC; ADDUPROF(p); } /* Allow a forced task switch. */ if (l->l_cpu->ci_want_resched) preempt(); userret(l); }