2011-08-14 Chris Johns <chrisj@rtems.org>

        * rtems/score/cpu.h: Clear the vector table for simple vectored
        interrupts.
        * irq.c: Add support for using the IIC with the Altera HAL.

3 files changed, 83 insertions, 7 deletions

diff --git a/cpukit/score/cpu/nios2/ChangeLog b/cpukit/score/cpu/nios2/ChangeLog
index dbf96749d0..94ca8ec29d 100644
--- a/cpukit/score/cpu/nios2/ChangeLog
+++ b/cpukit/score/cpu/nios2/ChangeLog
@@ -1,3 +1,9 @@
+2011-08-14	Chris Johns <chrisj@rtems.org>
+
+	* rtems/score/cpu.h: Clear the vector table for simple vectored
+	interrupts.
+	* irq.c: Add support for using the IIC with the Altera HAL.
+	
 2011-08-10	Sebastian Huber <sebastian.huber@embedded-brains.de>
 
 	* rtems/score/cpu.h: Removed superfluous comments.  Format.  Include
diff --git a/cpukit/score/cpu/nios2/irq.c b/cpukit/score/cpu/nios2/irq.c
index 5687f853c4..abfbeca0fb 100644
--- a/cpukit/score/cpu/nios2/irq.c
+++ b/cpukit/score/cpu/nios2/irq.c
@@ -34,7 +34,73 @@
 
 register unsigned long  *stack_ptr __asm__ ("sp");
 
+RTEMS_INLINE_ROUTINE void
+__Dipatch_interrupt_vector(uint32_t vector, proc_ptr pp)
+{
+  if ( _ISR_Vector_table[ vector] )
+  {
+    (*_ISR_Vector_table[ vector ])(vector, pp);
+  };
+}
+
+#if (RTEMS_NIOS_USE_ALT_HAL == TRUE)
+
+#include <bsp/alt/nios2.h>
+
+RTEMS_INLINE_ROUTINE void __IIC_Handler(void)
+{
+  uint32_t active;
+  uint32_t mask;
+  uint32_t vector;
+
+  /*
+   * Obtain from the interrupt controller a bit list of pending interrupts,
+   * and then process the highest priority interrupt. This process loops,
+   * loading the active interrupt list on each pass until alt_irq_pending()
+   * return zero.
+   *
+   * The maximum interrupt latency for the highest priority interrupt is
+   * reduced by finding out which interrupts are pending as late as possible.
+   * Consider the case where the high priority interupt is asserted during
+   * the interrupt entry sequence for a lower priority interrupt to see why
+   * this is the case.
+   */
+
+  NIOS2_READ_IPENDING (active);
+
+  while (active)
+  {
+    vector = 0;
+    mask = 1;
+
+    /*
+     * Test each bit in turn looking for an active interrupt. Once one is
+     * found, the interrupt handler asigned by a call to alt_irq_register() is
+     * called to clear the interrupt condition.
+     */
+
+    while (active)
+    {
+      if (active & mask)
+      {
+        __Dipatch_interrupt_vector(vector, NULL);
+        active &= ~mask;
+      }
+      mask <<= 1;
+      ++vector;
+    };
+
+    NIOS2_READ_IPENDING (active);
+  }
+  
+}
+#endif
+
+#if (RTEMS_NIOS_USE_ALT_HAL == TRUE)
+void __ISR_Handler(void)
+#else
 void __ISR_Handler(uint32_t vector, CPU_Interrupt_frame *ifr)
+#endif
 {
   register uint32_t   level;
 
@@ -52,11 +118,12 @@ void __ISR_Handler(uint32_t vector, CPU_Interrupt_frame *ifr)
 
   _Thread_Dispatch_increment_disable_level();
 
-  if ( _ISR_Vector_table[ vector] )
-  {
-    (*_ISR_Vector_table[ vector ])(vector, ifr);
-  };
-
+#if (RTEMS_NIOS_USE_ALT_HAL == TRUE)
+  __IIC_Handler();
+#else
+  __Dipatch_interrupt_vector(vector, ifr);
+#endif
+  
   /* Make sure that interrupts are disabled again */
   _CPU_ISR_Disable( level );
 
@@ -87,5 +154,3 @@ void __Exception_Handler(CPU_Exception_frame *efr)
 {
   _CPU_Fatal_halt(0xECC0);
 }
-
-
diff --git a/cpukit/score/cpu/nios2/rtems/score/cpu.h b/cpukit/score/cpu/nios2/rtems/score/cpu.h
index 4ace4c4f3a..61a1b421b8 100644
--- a/cpukit/score/cpu/nios2/rtems/score/cpu.h
+++ b/cpukit/score/cpu/nios2/rtems/score/cpu.h
@@ -182,7 +182,12 @@ typedef struct {
   uint32_t ipending;
 } CPU_Exception_frame;
 
+#if (CPU_SIMPLE_VECTORED_INTERRUPTS == TRUE)
+#define _CPU_Initialize_vectors() \
+  memset(_ISR_Vector_table, 0, sizeof(ISR_Handler_entry) * ISR_NUMBER_OF_VECTORS)
+#else
 #define _CPU_Initialize_vectors()
+#endif
 
 #define _CPU_ISR_Disable( _isr_cookie ) \
   do { \