text: /*
   * Copyright 2002 by Peter Grehan. 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. The name of the author may not 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 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.
   *
   * $FreeBSD: src/sys/powerpc/powerpc/interrupt.c,v 1.3 2003/01/08 12:20:46 grehan Exp $
   */
  
  /*
   * Interrupts are dispatched to here from locore asm
   */
  
  #include <sys/cdefs.h>                  /* RCS ID & Copyright macro defns */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/bus.h>
  #include <sys/interrupt.h>
  #include <sys/kernel.h>
  #include <sys/kthread.h>
  #include <sys/ktr.h>
  #include <sys/lock.h>
  #include <sys/malloc.h>
  #include <sys/mutex.h>
  #include <sys/proc.h>
  #include <sys/smp.h>
  #include <sys/unistd.h>
  #include <sys/vmmeter.h>
  
  #include <machine/cpu.h>
  #include <machine/db_machdep.h>
  #include <machine/fpu.h>
  #include <machine/frame.h>
  #include <machine/pcb.h>
  #include <machine/psl.h>
  #include <machine/trap.h>
  #include <machine/spr.h>
  #include <machine/sr.h>
  #include <machine/interruptvar.h>
  
  void powerpc_interrupt(struct trapframe *);
  
  /*
   * External interrupt install routines
   */
  static void (*powerpc_extintr_handler)(void);
  
  void
  ext_intr_install(void (*new_extint)(void))
  {
  	powerpc_extintr_handler = new_extint;
  }
  
  extern void	decr_intr(struct clockframe *);
  extern void	trap(struct trapframe *);
  
  /*
   * A very short dispatch, to try and maximise assembler code use
   * between all exception types. Maybe 'true' interrupts should go
   * here, and the trap code can come in separately
   */
  void
  powerpc_interrupt(struct trapframe *framep)
  {
          struct thread *td;
  	struct clockframe ckframe;
  
  	td = curthread;
  
  	switch (framep->exc) {
  	case EXC_EXI:
  		atomic_add_int(&td->td_intr_nesting_level, 1);
  		(*powerpc_extintr_handler)();
  		atomic_subtract_int(&td->td_intr_nesting_level, 1);	
  		break;
  
  	case EXC_DECR:
  		atomic_add_int(&td->td_intr_nesting_level, 1);
  		ckframe.srr0 = framep->srr0;
  		ckframe.srr1 = framep->srr1;
  		decr_intr(&ckframe);
  		atomic_subtract_int(&td->td_intr_nesting_level, 1);	
  		break;
  
  	default:
  		/*
  		 * Re-enable interrupts and call the generic trap code
  		 */
  #if 0
  		printf("powerpc_interrupt: got trap\n");
  		mtmsr(mfmsr() | PSL_EE);
  		isync();
  #endif
  		trap(framep);
  	}	        
  }
  