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/*

 *

 *  This file contains the implementation of the function described in irq.h

 *

 *  Copyright (C) 1998, 1999 valette@crf.canon.fr

 *

 *  The license and distribution terms for this file may be

 *  found in found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  $Id: irq.c,v 1.2 2001-09-27 12:01:06 chris Exp $

 */

#include <bsp.h>

#include <bsp/irq.h>

#include <bsp/openpic.h>

#include <rtems/score/thread.h>

#include <rtems/score/apiext.h>

#include <libcpu/raw_exception.h>

#include <bsp/vectors.h>

#include <libcpu/cpu.h>

#define RAVEN_INTR_ACK_REG 0xfeff0030

/*

 * pointer to the mask representing the additionnal irq vectors

 * that must be disabled when a particular entry is activated.

 * They will be dynamically computed from teh prioruty table given

 * in BSP_rtems_irq_mngt_set();

 * CAUTION : this table is accessed directly by interrupt routine

 *           prologue.

 */

rtems_i8259_masks       irq_mask_or_tbl[BSP_IRQ_NUMBER];

/*

 * default handler connected on each irq after bsp initialization

 */

static rtems_irq_connect_data   default_rtems_entry;

/*

 * location used to store initial tables used for interrupt

 * management.

 */

static rtems_irq_global_settings*       internal_config;

static rtems_irq_connect_data*          rtems_hdl_tbl;

/*

 * Check if IRQ is an ISA IRQ

 */

static inline int is_isa_irq(const rtems_irq_symbolic_name irqLine)

{

  return (((int) irqLine <= BSP_ISA_IRQ_MAX_OFFSET) &

          ((int) irqLine >= BSP_ISA_IRQ_LOWEST_OFFSET)

         );

}

/*

 * Check if IRQ is an OPENPIC IRQ

 */

static inline int is_pci_irq(const rtems_irq_symbolic_name irqLine)

{

  return (((int) irqLine <= BSP_PCI_IRQ_MAX_OFFSET) &

          ((int) irqLine >= BSP_PCI_IRQ_LOWEST_OFFSET)

         );

}

/*

 * Check if IRQ is a Porcessor IRQ

 */

static inline int is_processor_irq(const rtems_irq_symbolic_name irqLine)

{

  return (((int) irqLine <= BSP_PROCESSOR_IRQ_MAX_OFFSET) &

          ((int) irqLine >= BSP_PROCESSOR_IRQ_LOWEST_OFFSET)

         );

}

/*

 * ------------------------ RTEMS Irq helper functions ----------------

 */

/*

 * Caution : this function assumes the variable "internal_config"

 * is already set and that the tables it contains are still valid

 * and accessible.

 */

static void compute_i8259_masks_from_prio ()

{

  unsigned int i;

  unsigned int j;

  /*

   * Always mask at least current interrupt to prevent re-entrance

   */

  for (i=BSP_ISA_IRQ_LOWEST_OFFSET; i < BSP_ISA_IRQ_NUMBER; i++) {

    * ((unsigned short*) &irq_mask_or_tbl[i]) = (1 << i);

    for (j = BSP_ISA_IRQ_LOWEST_OFFSET; j < BSP_ISA_IRQ_NUMBER; j++) {

      /*

       * Mask interrupts at i8259 level that have a lower priority

       */

      if (internal_config->irqPrioTbl [i] > internal_config->irqPrioTbl [j]) {

        * ((unsigned short*) &irq_mask_or_tbl[i]) |= (1 << j);

      }

    }

  }

}

/*

 * This function check that the value given for the irq line

 * is valid.

 */

static int isValidInterrupt(int irq)

{

  if ( (irq < BSP_LOWEST_OFFSET) || (irq > BSP_MAX_OFFSET))

    return 0;

  return 1;

}

/*

 * ------------------------ RTEMS Single Irq Handler Mngt Routines ----------------

 */

int BSP_install_rtems_irq_handler  (const rtems_irq_connect_data* irq)

{

    unsigned int level;

    if (!isValidInterrupt(irq->name)) {

      return 0;

    }

    /*

     * Check if default handler is actually connected. If not issue an error.

     * You must first get the current handler via i386_get_current_idt_entry

     * and then disconnect it using i386_delete_idt_entry.

     * RATIONALE : to always have the same transition by forcing the user

     * to get the previous handler before accepting to disconnect.

     */

    if (rtems_hdl_tbl[irq->name].hdl != default_rtems_entry.hdl) {

      return 0;

    }

    _CPU_ISR_Disable(level);

    /*

     * store the data provided by user

     */

    rtems_hdl_tbl[irq->name] = *irq;

    if (is_isa_irq(irq->name)) {

      /*

       * Enable interrupt at PIC level

       */

      BSP_irq_enable_at_i8259s (irq->name);

    }

    if (is_pci_irq(irq->name)) {

      /*

       * Enable interrupt at OPENPIC level

       */

      openpic_enable_irq ((int) irq->name - BSP_PCI_IRQ_LOWEST_OFFSET);

    }

    if (is_processor_irq(irq->name)) {

      /*

       * Enable exception at processor level

       */

    }

    /*

     * Enable interrupt on device

     */

    irq->on(irq);

    _CPU_ISR_Enable(level);

    return 1;

}

int BSP_get_current_rtems_irq_handler   (rtems_irq_connect_data* irq)

{

     if (!isValidInterrupt(irq->name)) {

      return 0;

     }

     *irq = rtems_hdl_tbl[irq->name];

     return 1;

}

int BSP_remove_rtems_irq_handler  (const rtems_irq_connect_data* irq)

{

    unsigned int level;

    if (!isValidInterrupt(irq->name)) {

      return 0;

    }

    /*

     * Check if default handler is actually connected. If not issue an error.

     * You must first get the current handler via i386_get_current_idt_entry

     * and then disconnect it using i386_delete_idt_entry.

     * RATIONALE : to always have the same transition by forcing the user

     * to get the previous handler before accepting to disconnect.

     */

    if (rtems_hdl_tbl[irq->name].hdl != irq->hdl) {

      return 0;

    }

    _CPU_ISR_Disable(level);

    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

     */

    rtems_hdl_tbl[irq->name] = default_rtems_entry;

    _CPU_ISR_Enable(level);

    return 1;

}

/*

 * ------------------------ RTEMS Global Irq Handler Mngt 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_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]);

      }

      else {

        rtems_hdl_tbl[i].off(&rtems_hdl_tbl[i]);

        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++) {

      openpic_set_priority(0, 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]);

      }

      else {

        rtems_hdl_tbl[i].off(&rtems_hdl_tbl[i]);

        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]);

      }

      else {

        rtems_hdl_tbl[i].off(&rtems_hdl_tbl[i]);

      }

    }

    _CPU_ISR_Enable(level);

    return 1;

}

int BSP_rtems_irq_mngt_get(rtems_irq_global_settings** config)

{

    *config = internal_config;

    return 0;

}

static unsigned 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;                  /* 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) {

    ++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();

  _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 {

    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...

   */

}