hw_opic.c

这个是LINUX下的GDB调度工具的源码

  opic->nr_interprocessor_interrupts = 4;
  opic->nr_timer_interrupts = 4;


  /* create space for the interrupt source registers */
  if (opic->interrupt_source != NULL) {
    memset(opic->interrupt_source, 0, opic->sizeof_interrupt_source);
  }
  else {
    opic->nr_interrupt_sources = (opic->nr_external_interrupts
				  + opic->nr_interprocessor_interrupts
				  + opic->nr_timer_interrupts);
    if (opic->nr_interrupt_sources > max_nr_interrupt_sources)
      device_error(me, "number of interrupt sources exceeded");
    opic->sizeof_interrupt_source = (sizeof(opic_interrupt_source)
				     * opic->nr_interrupt_sources);
    opic->interrupt_source = zalloc(opic->sizeof_interrupt_source);
    opic->external_interrupt_source = opic->interrupt_source;
    opic->interprocessor_interrupt_source = (opic->external_interrupt_source
					     + opic->nr_external_interrupts);
    opic->timer_interrupt_source = (opic->interprocessor_interrupt_source
				    + opic->nr_interprocessor_interrupts);
  }
  for (i = 0; i < opic->nr_interrupt_sources; i++) {
    opic_interrupt_source *source = &opic->interrupt_source[i];
    source->nr = i;
    source->is_masked = isu_mask_bit;
  }
  DTRACE(opic, ("interrupt sources - external %d, timer %d, ipi %d, total %d\n",
		opic->nr_external_interrupts,
		opic->nr_timer_interrupts,
		opic->nr_interprocessor_interrupts,
		opic->nr_interrupt_sources));


  /* timers or interprocessor interrupts */
  if (opic->timer != NULL)
    memset(opic->timer, 0, opic->sizeof_timer);
  else {
    opic->nr_timer_interrupts = 4;
    opic->sizeof_timer = sizeof(opic_timer) * opic->nr_timer_interrupts;
    opic->timer = zalloc(opic->sizeof_timer);
  }
  for (i = 0; i < opic->nr_timer_interrupts; i++) {
    opic_timer *timer = &opic->timer[i];
    timer->nr = i;
    timer->me = me;
    timer->opic = opic;
    timer->inhibited = 1;
    timer->interrupt_source = &opic->timer_interrupt_source[i];
  }
  if (device_find_property(me, "timer-frequency"))
    opic->timer_frequency = device_find_integer_property(me, "timer-frequency");
  else
    opic->timer_frequency = 1;


  /* create space for the interrupt destination registers */
  if (opic->interrupt_destination != NULL) {
    memset(opic->interrupt_destination, 0, opic->sizeof_interrupt_destination);
  }
  else {
    opic->nr_interrupt_destinations = tree_find_integer_property(me, "/openprom/options/smp");
    opic->sizeof_interrupt_destination = (sizeof(opic_interrupt_destination)
					  * opic->nr_interrupt_destinations);
    opic->interrupt_destination = zalloc(opic->sizeof_interrupt_destination);
    if (opic->nr_interrupt_destinations > max_nr_interrupt_destinations)
      device_error(me, "number of interrupt destinations exceeded");
  }
  for (i = 0; i < opic->nr_interrupt_destinations; i++) {
    opic_interrupt_destination *dest = &opic->interrupt_destination[i];
    dest->bit = (1 << i);
    dest->nr = i;
    dest->init_port = (device_interrupt_decode(me, "init0", output_port)
		       + i);
    dest->intr_port = (device_interrupt_decode(me, "intr0", output_port)
		       + i);
    dest->base_priority = max_nr_task_priorities - 1;
  }
  DTRACE(opic, ("interrupt destinations - total %d\n",
		(int)opic->nr_interrupt_destinations));
  

  /* verify and print out the ISU's */
  for (isb = 0; isb < opic->nr_isu_blocks; isb++) {
    unsigned correct_size;
    if ((opic->isu_block[isb].address % opic_alignment) != 0)
      device_error(me, "interrupt source unit %d address not aligned to %d byte boundary",
		   isb, opic_alignment);
    correct_size = opic->isu_block[isb].range * sizeof_isu_register_block;
    if (opic->isu_block[isb].size != correct_size)
      device_error(me, "interrupt source unit %d (reg %d) has an incorrect size, should be 0x%x",
		   isb, opic->isu_block[isb].reg, correct_size);
    DTRACE(opic, ("interrupt source unit block %ld - address %d:0x%lx, size 0x%lx, int-number %ld, range %ld\n",
		  (long)isb,
		  (int)opic->isu_block[isb].space,
		  (unsigned long)opic->isu_block[isb].address,
		  (unsigned long)opic->isu_block[isb].size,
		  (long)opic->isu_block[isb].int_number,
		  (long)opic->isu_block[isb].range));
  }


  /* verify and print out the IDU */
  {
    unsigned correct_size;
    unsigned alternate_size;
    if ((opic->idu.address % opic_alignment) != 0)
      device_error(me, "interrupt delivery unit not aligned to %d byte boundary",
		   opic_alignment);
    correct_size = (idu_per_processor_register_base
		    + (sizeof_idu_per_processor_register_block
		       * opic->nr_interrupt_destinations));
    alternate_size = (idu_per_processor_register_base
		      + (sizeof_idu_per_processor_register_block
			 * max_nr_interrupt_destinations));
    if (opic->idu.size != correct_size
	&& opic->idu.size != alternate_size)
      device_error(me, "interrupt delivery unit has incorrect size, should be 0x%x or 0x%x",
		   correct_size, alternate_size);
    DTRACE(opic, ("interrupt delivery unit - address %d:0x%lx, size 0x%lx\n",
		  (int)opic->idu.space,
		  (unsigned long)opic->idu.address,
		  (unsigned long)opic->idu.size));
  }

  /* initialize the init interrupts */
  opic->init = 0;


  /* vendor ident */
  if (device_find_property(me, "vendor-identification") != NULL)
    opic->vendor_identification = device_find_integer_property(me, "vendor-identification");
  else
    opic->vendor_identification = 0;

  /* misc registers */
  opic->spurious_vector = 0xff;

}


/* interrupt related actions */

static void
assert_interrupt(device *me,
		 hw_opic_device *opic,
		 opic_interrupt_destination *dest)
{
  ASSERT(dest >= opic->interrupt_destination);
  ASSERT(dest < opic->interrupt_destination + opic->nr_interrupt_destinations);
  DTRACE(opic, ("assert interrupt - intr port %d\n", dest->intr_port));
  device_interrupt_event(me, dest->intr_port, 1, NULL, 0);
}


static void
negate_interrupt(device *me,
		 hw_opic_device *opic,
		 opic_interrupt_destination *dest)
{
  ASSERT(dest >= opic->interrupt_destination);
  ASSERT(dest < opic->interrupt_destination + opic->nr_interrupt_destinations);
  DTRACE(opic, ("negate interrupt - intr port %d\n", dest->intr_port));
  device_interrupt_event(me, dest->intr_port, 0, NULL, 0);
}


static int
can_deliver(device *me,
	    opic_interrupt_source *source,
	    opic_interrupt_destination *dest)
{
  return (source != NULL && dest != NULL
	  && source->priority > dest->base_priority
	  && (dest->current_in_service == NULL
	      || source->priority > dest->current_in_service->priority));
}


static unsigned
deliver_pending(device *me,
		hw_opic_device *opic,
		opic_interrupt_destination *dest)
{
  ASSERT(can_deliver(me, dest->current_pending, dest));
  dest->current_in_service = dest->current_pending;
  dest->current_in_service->in_service |= dest->bit;
  if (!dest->current_pending->is_level_triggered) {
    if (dest->current_pending->is_multicast)
      dest->current_pending->pending &= ~dest->bit;
    else
      dest->current_pending->pending = 0;
  }
  dest->current_pending = NULL;
  negate_interrupt(me, opic, dest);
  return dest->current_in_service->vector;
}


typedef enum {
  pending_interrupt,
  in_service_interrupt,
} interrupt_class;

static opic_interrupt_source *
find_interrupt_for_dest(device *me,
			hw_opic_device *opic,
			opic_interrupt_destination *dest,
			interrupt_class class)
{
  int i;
  opic_interrupt_source *pending = NULL;
  for (i = 0; i < opic->nr_interrupt_sources; i++) {
    opic_interrupt_source *src = &opic->interrupt_source[i];
    /* is this a potential hit? */
    switch (class) {
    case in_service_interrupt:
      if ((src->in_service & dest->bit) == 0)
	continue;
      break;
    case pending_interrupt:
      if ((src->pending & dest->bit) == 0)
	continue;
      break;
    }
    /* see if it is the highest priority */
    if (pending == NULL)
      pending = src;
    else if (src->priority > pending->priority)
      pending = src;
  }
  return pending;
}


static opic_interrupt_destination *
find_lowest_dest(device *me, 
		 hw_opic_device *opic,
		 opic_interrupt_source *src)
{
  int i;
  opic_interrupt_destination *lowest = NULL;
  for (i = 0; i < opic->nr_interrupt_destinations; i++) {
    opic_interrupt_destination *dest = &opic->interrupt_destination[i];
    if (src->destination & dest->bit) {
      if (dest->base_priority < src->priority) {
	if (lowest == NULL)
	  lowest = dest;
	else if (lowest->base_priority > dest->base_priority)
	  lowest = dest;
	else if (lowest->current_in_service != NULL
		 && dest->current_in_service == NULL)
	  lowest = dest; /* not doing anything */
	else if (lowest->current_in_service != NULL
		 && dest->current_in_service != NULL
		 && (lowest->current_in_service->priority
		     > dest->current_in_service->priority))
	  lowest = dest; /* less urgent */
	/* FIXME - need to be more fair */	
      }
    }
  }
  return lowest;
}


static void
handle_interrupt(device *me,
		 hw_opic_device *opic,
		 opic_interrupt_source *src,
		 int asserted)
{
  if (src->is_masked) {
    DTRACE(opic, ("interrupt %d - ignore masked\n", src->nr));
  }
  else if (src->is_multicast) {
    /* always try to deliver multicast interrupts - just easier */
    int i;
    ASSERT(!src->is_level_triggered);
    ASSERT(src->is_positive_polarity);
    ASSERT(asserted);
    for (i = 0; i < opic->nr_interrupt_destinations; i++) {
      opic_interrupt_destination *dest = &opic->interrupt_destination[i];
      if (src->destination & dest->bit) {
	if (src->pending & dest->bit) {
	  DTRACE(opic, ("interrupt %d - multicast still pending to %d\n",
			src->nr, dest->nr));
	}
	else if (can_deliver(me, src, dest)) {
	  dest->current_pending = src;
	  src->pending |= dest->bit;
	  assert_interrupt(me, opic, dest);
	  DTRACE(opic, ("interrupt %d - multicast to %d\n",
			src->nr, dest->nr));
	}
	else {
	  src->pending |= dest->bit;
	  DTRACE(opic, ("interrupt %d - multicast pending to %d\n",
			src->nr, dest->nr));
	}
      }
    }
  }
  else if (src->is_level_triggered
	   && src->is_positive_polarity
	   && !asserted) {
    if (src->pending)
      DTRACE(opic, ("interrupt %d - ignore withdrawn (active high)\n",
		    src->nr));
    else
      DTRACE(opic, ("interrupt %d - ignore low level (active high)\n",
		    src->nr));
    ASSERT(!src->is_multicast);
    src->pending = 0;
  }
  else if (src->is_level_triggered
	   && !src->is_positive_polarity
	   && asserted) {
    if (src->pending)
      DTRACE(opic, ("interrupt %d - ignore withdrawn (active low)\n",
		    src->nr));
    else
      DTRACE(opic, ("interrupt %d - ignore high level (active low)\n",
		    src->nr));

    ASSERT(!src->is_multicast);
    src->pending = 0;
  }
  else if (!src->is_level_triggered
	   && src->is_positive_polarity
	   && !asserted) {
    DTRACE(opic, ("interrupt %d - ignore falling edge (positive edge trigered)\n",
		  src->nr));
  }
  else if (!src->is_level_triggered
	   && !src->is_positive_polarity
	   && asserted) {
    DTRACE(opic, ("interrupt %d - ignore rising edge (negative edge trigered)\n",
		  src->nr));
  }
  else if (src->in_service != 0) {
    /* leave the interrupt where it is */
    ASSERT(!src->is_multicast);
    ASSERT(src->pending == 0 || src->pending == src->in_service);
    src->pending = src->in_service;
    DTRACE(opic, ("interrupt %ld - ignore already in service to 0x%lx\n",
		  (long)src->nr, (long)src->in_service));
  }
  else if (src->pending != 0) {
    DTRACE(opic, ("interrupt %ld - ignore still pending to 0x%lx\n",
		  (long)src->nr, (long)src->pending));
  }
  else {
    /* delivery is needed */
    opic_interrupt_destination *dest = find_lowest_dest(me, opic, src);
    if (can_deliver(me, src, dest)) {
      dest->current_pending = src;
      src->pending = dest->bit;
      DTRACE(opic, ("interrupt %d - delivered to %d\n", src->nr, dest->nr));
      assert_interrupt(me, opic, dest);
    }
    else {
      src->pending = src->destination; /* any can take this */
      DTRACE(opic, ("interrupt %ld - pending to 0x%lx\n",
		    (long)src->nr, (long)src->pending));
    }
  }
}

static unsigned
do_interrupt_acknowledge_register_N_read(device *me,
					 hw_opic_device *opic,
					 int dest_nr)
{
  opic_interrupt_destination *dest = &opic->interrupt_destination[dest_nr];
  unsigned vector;

  ASSERT(dest_nr >= 0 && dest_nr < opic->nr_interrupt_destinations);
  ASSERT(dest_nr == dest->nr);

  /* try the current pending */
  if (can_deliver(me, dest->current_pending, dest)) {
    ASSERT(dest->current_pending->pending & dest->bit);
    vector = deliver_pending(me, opic, dest);
    DTRACE(opic, ("interrupt ack %d - entering %d (pending) - vector %d (%d), priority %d\n",
		  dest->nr,
		  dest->current_in_service->nr,
		  dest->current_in_service->vector, vector,
		  dest->current_in_service->priority));
  }
  else {
    /* try for something else */
    dest->current_pending = find_interrupt_for_dest(me, opic, dest, pending_interrupt);
    if (can_deliver(me, dest->current_pending, dest)) {
      vector = deliver_pending(me, opic, dest);    
      DTRACE(opic, ("interrupt ack %d - entering %d (not pending) - vector %d (%d), priority %d\n",
		    dest->nr,
		    dest->current_in_service->nr,
		    dest->current_in_service->vector, vector,
		    dest->current_in_service->priority));
    }
    else {
      dest->current_pending = NULL;
      vector = opic->spurious_vector;
      DTRACE(opic, ("interrupt ack %d - spurious interrupt %d\n",
		    dest->nr, vector));
    }
  }
  return vector;
}


static void
do_end_of_interrupt_register_N_write(device *me,
				     hw_opic_device *opic,
				     int dest_nr,
				     unsigned reg)
{
  opic_interrupt_destination *dest = &opic->interrupt_destination[dest_nr];

  ASSERT(dest_nr >= 0 && dest_nr < opic->nr_interrupt_destinations);
  ASSERT(dest_nr == dest->nr);

  /* check the value written is zero */
  if (reg != 0) {
    DTRACE(opic, ("eoi %d - ignoring nonzero value\n", dest->nr));
  }

  /* user doing wierd things? */
  if (dest->current_in_service == NULL) {
    DTRACE(opic, ("eoi %d - strange, no current interrupt\n", dest->nr));
    return;
  }

  /* an internal stuff up? */
  if (!(dest->current_in_service->in_service & dest->bit)) {
    device_error(me, "eoi %d - current interrupt not in service", dest->nr);
  }

  /* find what was probably the previous in service interrupt */
  dest->current_in_service->in_service &= ~dest->bit;
  DTRACE(opic, ("eoi %d - ending %d - priority %d, vector %d\n",
		dest->nr,
		dest->current_in_service->nr,
		dest->current_in_service->priority,
		dest->current_in_service->vector));
  dest->current_in_service = find_interrupt_for_dest(me, opic, dest, in_service_interrupt);
  if (dest->current_in_service != NULL)
    DTRACE(opic, ("eoi %d - resuming %d - priority %d, vector %d\n",
		  dest->nr,
		  dest->current_in_service->nr,
		  dest->current_in_service->priority,
		  dest->current_in_service->vector));
  else
    DTRACE(opic, ("eoi %d - resuming none\n", dest->nr));