www.pudn.com > PlxSdk.rar > PlxInterrupt.c


/*******************************************************************************
 * Copyright (c) 2007 PLX Technology, Inc.
 *
 * PLX Technology Inc. licenses this software under specific terms and
 * conditions.  Use of any of the software or derviatives thereof in any
 * product without a PLX Technology chip is strictly prohibited.
 *
 * PLX Technology, Inc. provides this software AS IS, WITHOUT ANY WARRANTY,
 * EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  PLX makes no guarantee
 * or representations regarding the use of, or the results of the use of,
 * the software and documentation in terms of correctness, accuracy,
 * reliability, currentness, or otherwise; and you rely on the software,
 * documentation and results solely at your own risk.
 *
 * IN NO EVENT SHALL PLX BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS,
 * LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES
 * OF ANY KIND.  IN NO EVENT SHALL PLX'S TOTAL LIABILITY EXCEED THE SUM
 * PAID TO PLX FOR THE PRODUCT LICENSED HEREUNDER.
 *
 ******************************************************************************/

/******************************************************************************
 *
 * File Name:
 *
 *      PlxInterrupt.c
 *
 * Description:
 *
 *      This file handles interrupts for the PLX device
 *
 * Revision History:
 *
 *      04-01-07 : PLX SDK v5.00
 *
 ******************************************************************************/


#include 
#include 
#include 
#include 
#include 
#include 
#include   // Note: interrupt.h must be last to avoid compiler
                              //       errors with some 2.4 kernel headers
#include "PlxChipFn.h"
#include "PlxInterrupt.h"
#include "SupportFunc.h"




/******************************************************************************
 *
 * Function   :  OnInterrupt
 *
 * Description:  The Interrupt Service Routine for the PLX device
 *
 ******************************************************************************/
irqreturn_t
OnInterrupt(
    int   irq,
    void *dev_id
  #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
  , struct pt_regs *regs
  #endif
    )
{
    U32               RegPciInt;
    U32               InterruptSource;
    DEVICE_EXTENSION *pdx;


    // Get the device extension
    pdx = (DEVICE_EXTENSION *)dev_id;

    // Read interrupt status register
    RegPciInt =
        PLX_9000_REG_READ(
            pdx,
            PCI9030_INT_CTRL_STAT
            );

    /****************************************************
     * If the chip is in a low power state, then local
     * register reads are disabled and will always return
     * 0xFFFFFFFF.  If the PLX chip's interrupt is shared
     * with another PCI device, the PXL ISR may continue
     * to be called.  This case is handled to avoid
     * erroneous reporting of an active interrupt.
     ***************************************************/
    if (RegPciInt == 0xFFFFFFFF)
        return PLX_IRQ_RETVAL(IRQ_NONE);

    // Check for master PCI interrupt enable
    if ((RegPciInt & (1 << 6)) == 0)
        return PLX_IRQ_RETVAL(IRQ_NONE);

    // Verify that an interrupt is truly active

    // Clear the interrupt type flag
    InterruptSource = INTR_TYPE_NONE;

    // Check if Local Interrupt 1 is active and not masked
    if ((RegPciInt & (1 << 2)) && (RegPciInt & (1 << 0)))
    {
        InterruptSource |= INTR_TYPE_LOCAL_1;
    }

    // Check if Local Interrupt 2 is active and not masked
    if ((RegPciInt & (1 << 5)) && (RegPciInt & (1 << 3)))
    {
        InterruptSource |= INTR_TYPE_LOCAL_2;
    }

    // Software Interrupt
    if (RegPciInt & (1 << 7))
    {
        InterruptSource |= INTR_TYPE_SOFTWARE;
    }

    // Return if no interrupts are active
    if (InterruptSource == INTR_TYPE_NONE)
        return PLX_IRQ_RETVAL(IRQ_NONE);

    // At this point, the device interrupt is verified

    // Mask the PCI Interrupt
    PLX_9000_REG_WRITE(
        pdx,
        PCI9030_INT_CTRL_STAT,
        RegPciInt & ~(1 << 6)
        );

    //
    // Schedule deferred procedure (DPC) to complete interrupt processing
    //

    // Provide interrupt source to DPC
    pdx->Source_Ints = InterruptSource;

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
    // Reset task structure
    pdx->Task_DpcForIsr.sync = 0;

    // Add task to system immediate queue
    queue_task(
        &(pdx->Task_DpcForIsr),
        &tq_immediate
        );

    // Mark queue for Bottom-half processing
    mark_bh(
        IMMEDIATE_BH
        );
#else
    // Add task to system work queue
    schedule_work(
        &(pdx->Task_DpcForIsr)
        );
#endif

    return PLX_IRQ_RETVAL(IRQ_HANDLED);
}




/******************************************************************************
 *
 * Function   :  DpcForIsr
 *
 * Description:  This routine will be triggered by the ISR to service an interrupt
 *
 ******************************************************************************/
void
DpcForIsr(
    PLX_DPC_PARAM *pArg1
    )
{
    U32                 RegValue;
    DEVICE_EXTENSION   *pdx;
    PLX_INTERRUPT_DATA  IntData;


    // Get the device extension
    pdx =
        container_of(
            pArg1,
            DEVICE_EXTENSION,
            Task_DpcForIsr
            );

    // Get interrupt source
    IntData.Source_Ints     = pdx->Source_Ints;
    IntData.Source_Doorbell = 0;

    // Local Interrupt 1
    if (IntData.Source_Ints & INTR_TYPE_LOCAL_1)
    {
        // Synchronize access to Interrupt Control/Status Register
        spin_lock(
            &(pdx->Lock_Isr)
            );

        // Check if this is an edge-triggered interrupt
        RegValue =
            PLX_9000_REG_READ(
                pdx,
                PCI9030_INT_CTRL_STAT
                );

        if ((RegValue & (1 << 1)) && (RegValue & (1 << 8)))
        {
            // Clear edge-triggered interrupt
            PLX_9000_REG_WRITE(
                pdx,
                PCI9030_INT_CTRL_STAT,
                RegValue | (1 << 10)
                );
        }
        else
        {
            // Mask Local Interrupt 1
            PLX_9000_REG_WRITE(
                pdx,
                PCI9030_INT_CTRL_STAT,
                RegValue & ~(1 << 0)
                );
        }

        spin_unlock(
            &(pdx->Lock_Isr)
            );
    }

    // Local Interrupt 2
    if (IntData.Source_Ints & INTR_TYPE_LOCAL_2)
    {
        // Synchronize access to Interrupt Control/Status Register
        spin_lock(
            &(pdx->Lock_Isr)
            );

        // Check if this is an edge-triggered interrupt
        RegValue =
            PLX_9000_REG_READ(
                pdx,
                PCI9030_INT_CTRL_STAT
                );

        if ((RegValue & (1 << 4)) && (RegValue & (1 << 9)))
        {
            // Clear edge-triggered interrupt
            PLX_9000_REG_WRITE(
                pdx,
                PCI9030_INT_CTRL_STAT,
                RegValue | (1 << 11)
                );
        }
        else
        {
            // Mask Local Interrupt 2
            PLX_9000_REG_WRITE(
                pdx,
                PCI9030_INT_CTRL_STAT,
                RegValue & ~(1 << 3)
                );
        }

        spin_unlock(
            &(pdx->Lock_Isr)
            );
    }

    // Software Interrupt
    if (IntData.Source_Ints & INTR_TYPE_SOFTWARE)
    {
        // Synchronize access to Interrupt Control/Status Register
        spin_lock(
            &(pdx->Lock_Isr)
            );

        // Clear the software interrupt
        RegValue =
            PLX_9000_REG_READ(
                pdx,
                PCI9030_INT_CTRL_STAT
                );

        PLX_9000_REG_WRITE(
            pdx,
            PCI9030_INT_CTRL_STAT,
            RegValue & ~(1 << 7)
            );

        spin_unlock(
            &(pdx->Lock_Isr)
            );
    }

    // Signal any objects waiting for notification
    PlxSignalNotifications(
        pdx,
        &IntData
        );

    // Re-enable interrupts
    PlxChipInterruptsEnable(
        pdx
        );
}