irq.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

       if (rtems_hdl_tbl[irq->name].hdl != irq->hdl) 
       {
          _CPU_ISR_Enable(level);
         return 0;
       }
    }

    if (is_isa_irq(irq->name)) {
      /*
       * disable interrupt at PIC level
       */
      BSP_irq_disable_at_i8259s (irq->name);
    }
    if (is_pci_irq(irq->name)) {
      /*
       * disable interrupt at OPENPIC level
       */
      openpic_disable_irq ((int) irq->name - BSP_PCI_IRQ_LOWEST_OFFSET);
    }
    if (is_processor_irq(irq->name)) {
      /*
       * disable exception at processor level
       */
    }    

    /*
     * Disable interrupt on device
     */
    irq->off(irq);

    /*
     * restore the default irq value
     */
    if( !vchain )
    {
       /* single handler vector... */
       rtems_hdl_tbl[irq->name] = default_rtems_entry;
    }
    else
    {
       if( pchain )
       {
          /* non-first handler being removed */
          pchain->next_handler = vchain->next_handler;
       }
       else
       {
          /* first handler isn't malloc'ed, so just overwrite it.  Since
          the contents of vchain are being struct copied, vchain itself
          goes away */
          rtems_hdl_tbl[irq->name]= *vchain;
       }
       free(vchain);
    }

    _CPU_ISR_Enable(level);

    return 1;
}

/*
 * RTEMS Global Interrupt Handler Management Routines 
 */

int BSP_rtems_irq_mngt_set(rtems_irq_global_settings* config)
{
    int i;
    unsigned int level;
   /*
    * Store various code accelerators
    */
    internal_config 		= config;
    default_rtems_entry 	= config->defaultEntry;
    rtems_hdl_tbl 		= config->irqHdlTbl;

    _CPU_ISR_Disable(level);
    /*
     * set up internal tables used by rtems interrupt prologue
     */
    /*
     * start with ISA IRQ
     */
    compute_i8259_masks_from_prio ();

    for (i=BSP_ISA_IRQ_LOWEST_OFFSET; i < BSP_ISA_IRQ_LOWEST_OFFSET + BSP_ISA_IRQ_NUMBER; i++) {
      if (rtems_hdl_tbl[i].hdl != default_rtems_entry.hdl) {
         BSP_irq_enable_at_i8259s (i);

         /* rtems_hdl_tbl[i].on(&rtems_hdl_tbl[i]); */
         {
            rtems_irq_connect_data* vchain;
            for( vchain = &rtems_hdl_tbl[i];
                 ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
                 vchain = (rtems_irq_connect_data*)vchain->next_handler )
            {
               vchain->on(vchain);
            }
         }
      }
      else {
         /* rtems_hdl_tbl[i].off(&rtems_hdl_tbl[i]); */
         {
            rtems_irq_connect_data* vchain;
            for( vchain = &rtems_hdl_tbl[i];
                 ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
                 vchain = (rtems_irq_connect_data*)vchain->next_handler )
            {
               vchain->off(vchain);
            }
         }
         BSP_irq_disable_at_i8259s (i);
      }
    }
    /*
     * must enable slave pic anyway
     */
    BSP_irq_enable_at_i8259s (2);
    /*
     * continue with PCI IRQ
     */
    for (i=BSP_PCI_IRQ_LOWEST_OFFSET; i < BSP_PCI_IRQ_LOWEST_OFFSET + BSP_PCI_IRQ_NUMBER ; i++) {
      /*
       * Note that openpic_set_priority() sets the TASK priority of the PIC
       */
      openpic_set_source_priority(i - BSP_PCI_IRQ_LOWEST_OFFSET,
				  internal_config->irqPrioTbl[i]);
      if (rtems_hdl_tbl[i].hdl != default_rtems_entry.hdl) {
         openpic_enable_irq ((int) i - BSP_PCI_IRQ_LOWEST_OFFSET);
         /* rtems_hdl_tbl[i].on(&rtems_hdl_tbl[i]); */
         {
            rtems_irq_connect_data* vchain;
            for( vchain = &rtems_hdl_tbl[i];
                 ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
                 vchain = (rtems_irq_connect_data*)vchain->next_handler )
            {
               vchain->on(vchain);
            }
         }

      }
      else {
         /* rtems_hdl_tbl[i].off(&rtems_hdl_tbl[i]); */
         {
            rtems_irq_connect_data* vchain;
            for( vchain = &rtems_hdl_tbl[i];
                 ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
                 vchain = (rtems_irq_connect_data*)vchain->next_handler )
            {
               vchain->off(vchain);
            }
         }
         
         openpic_disable_irq ((int) i - BSP_PCI_IRQ_LOWEST_OFFSET);
      }
    }
    /*
     * Must enable PCI/ISA bridge IRQ
     */
    openpic_enable_irq (0);
    /*
     * finish with Processor exceptions handled like IRQ
     */
    for (i=BSP_PROCESSOR_IRQ_LOWEST_OFFSET; i < BSP_PROCESSOR_IRQ_LOWEST_OFFSET + BSP_PROCESSOR_IRQ_NUMBER; i++) {
      if (rtems_hdl_tbl[i].hdl != default_rtems_entry.hdl) {
         /* rtems_hdl_tbl[i].on(&rtems_hdl_tbl[i]); */
         {
            rtems_irq_connect_data* vchain;
            for( vchain = &rtems_hdl_tbl[i];
                 ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
                 vchain = (rtems_irq_connect_data*)vchain->next_handler )
            {
               vchain->on(vchain);
            }
         }

      }
      else {
         /* rtems_hdl_tbl[i].off(&rtems_hdl_tbl[i]); */
         {
            rtems_irq_connect_data* vchain;
            for( vchain = &rtems_hdl_tbl[i];
                 ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
                 vchain = (rtems_irq_connect_data*)vchain->next_handler )
            {
               vchain->off(vchain);
            }
         }

      }
    }
    _CPU_ISR_Enable(level);
    return 1;
}

int BSP_rtems_irq_mngt_get(rtems_irq_global_settings** config)
{
    *config = internal_config;
    return 0;
}    

int _BSP_vme_bridge_irq = -1;
 
unsigned BSP_spuriousIntr = 0;
/*
 * High level IRQ handler called from shared_raw_irq_code_entry
 */
void C_dispatch_irq_handler (CPU_Interrupt_frame *frame, unsigned int excNum)
{
  register unsigned int irq;
  register unsigned isaIntr;                  /* boolean */
  register unsigned oldMask = 0;	      /* old isa pic masks */
  register unsigned newMask;                  /* new isa pic masks */
  register unsigned msr;
  register unsigned new_msr;

  if (excNum == ASM_DEC_VECTOR) {
    _CPU_MSR_GET(msr);
    new_msr = msr | MSR_EE;
    _CPU_MSR_SET(new_msr);
    
    rtems_hdl_tbl[BSP_DECREMENTER].hdl();

    _CPU_MSR_SET(msr);
    return;
  }

  irq = openpic_irq(0);
  if (irq == OPENPIC_VEC_SPURIOUS) {
    ++BSP_spuriousIntr;
    return;
  }
  isaIntr = (irq == BSP_PCI_ISA_BRIDGE_IRQ);
  if (isaIntr)  {
    /*
     * Acknowledge and read 8259 vector
     */
    irq = (unsigned int) (*(unsigned char *) RAVEN_INTR_ACK_REG);
    /*
     * store current PIC mask
     */
    oldMask = i8259s_cache;
    newMask = oldMask | irq_mask_or_tbl [irq];
    i8259s_cache = newMask;
    outport_byte(PIC_MASTER_IMR_IO_PORT, i8259s_cache & 0xff);
    outport_byte(PIC_SLAVE_IMR_IO_PORT, ((i8259s_cache & 0xff00) >> 8));
    BSP_irq_ack_at_i8259s (irq);
    openpic_eoi(0);
  }
  _CPU_MSR_GET(msr);
  new_msr = msr | MSR_EE;
  _CPU_MSR_SET(new_msr);
    
  /* rtems_hdl_tbl[irq].hdl(); */
  {
     rtems_irq_connect_data* vchain;
     for( vchain = &rtems_hdl_tbl[irq];
          ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl);
          vchain = (rtems_irq_connect_data*)vchain->next_handler )
     {
        vchain->hdl();
     }
  }


  _CPU_MSR_SET(msr);

  if (isaIntr)  {
    i8259s_cache = oldMask;
    outport_byte(PIC_MASTER_IMR_IO_PORT, i8259s_cache & 0xff);
    outport_byte(PIC_SLAVE_IMR_IO_PORT, ((i8259s_cache & 0xff00) >> 8));
  }
  else {
#ifdef BSP_PCI_VME_DRIVER_DOES_EOI
	/* leave it to the VME bridge driver to do EOI, so
     * it can re-enable the openpic while handling
     * VME interrupts (-> VME priorities in software)
	 */
	if (_BSP_vme_bridge_irq != irq)
#endif
    		openpic_eoi(0);
  }
}
    
    
  
void _ThreadProcessSignalsFromIrq (BSP_Exception_frame* ctx)
{
  /*
   * Process pending signals that have not already been
   * processed by _Thread_Displatch. This happens quite
   * unfrequently : the ISR must have posted an action
   * to the current running thread.
   */
  if ( _Thread_Do_post_task_switch_extension ||
       _Thread_Executing->do_post_task_switch_extension ) {
    _Thread_Executing->do_post_task_switch_extension = FALSE;
    _API_extensions_Run_postswitch();
  }
  /*
   * I plan to process other thread related events here.
   * This will include DEBUG session requested from keyboard...
   */
}