1 files changed, 98 insertions, 0 deletions
diff --git a/sim/ppc/hw_pic.c b/sim/ppc/hw_pic.c
new file mode 100644
index 0000000..3203f8c
--- /dev/null
+++ b/sim/ppc/hw_pic.c
@@ -0,0 +1,98 @@
+/* ICU device: icu@<address>
+
+   <address> : read - processor nr
+   <address> : write - interrupt processor nr
+   <address> + 4 : read - nr processors
+
+   Single byte registers that control a simple ICU.
+
+   Illustrates passing of events to parent device. Passing of
+   interrupts to an interrupt destination. */
+
+
+static unsigned
+icu_io_read_buffer_callback(device *me,
+			    void *dest,
+			    int space,
+			    unsigned_word addr,
+			    unsigned nr_bytes,
+			    cpu *processor,
+			    unsigned_word cia)
+{
+  memset(dest, 0, nr_bytes);
+  switch (addr & 4) {
+  case 0:
+    *(unsigned_1*)dest = cpu_nr(processor);
+    break;
+  case 4:
+    *(unsigned_1*)dest =
+      device_find_integer_property(me, "/openprom/options/smp");
+    break;
+  }
+  return nr_bytes;
+}
+
+
+static unsigned
+icu_io_write_buffer_callback(device *me,
+			     const void *source,
+			     int space,
+			     unsigned_word addr,
+			     unsigned nr_bytes,
+			     cpu *processor,
+			     unsigned_word cia)
+{
+  unsigned_1 val = H2T_1(*(unsigned_1*)source);
+  /* tell the parent device that the interrupt lines have changed.
+     For this fake ICU.  The interrupt lines just indicate the cpu to
+     interrupt next */
+  device_interrupt_event(me,
+			 val, /*my_port*/
+			 val, /*val*/
+			 processor, cia);
+  return nr_bytes;
+}
+
+static void
+icu_do_interrupt(event_queue *queue,
+		 void *data)
+{
+  cpu *target = (cpu*)data;
+  /* try to interrupt the processor.  If the attempt fails, try again
+     on the next tick */
+  if (!external_interrupt(target))
+    event_queue_schedule(queue, 1, icu_do_interrupt, target);
+}
+
+
+static void
+icu_interrupt_event_callback(device *me,
+			     int my_port,
+			     device *source,
+			     int source_port,
+			     int level,
+			     cpu *processor,
+			     unsigned_word cia)
+{
+  /* the interrupt controller can't interrupt a cpu at any time.
+     Rather it must synchronize with the system clock before
+     performing an interrupt on the given processor */
+  psim *system = cpu_system(processor);
+  cpu *target = psim_cpu(system, my_port);
+  if (target != NULL) {
+    event_queue *events = cpu_event_queue(target);
+    event_queue_schedule(events, 1, icu_do_interrupt, target);
+  }
+}
+
+static device_callbacks const icu_callbacks = {
+  { generic_device_init_address, },
+  { NULL, }, /* address */
+  { icu_io_read_buffer_callback,
+    icu_io_write_buffer_callback, },
+  { NULL, }, /* DMA */
+  { icu_interrupt_event_callback, },
+  { NULL, }, /* unit */
+};
+
+