/******************************************************************************
* Copyright (C) 2010 - 2022 Xilinx, Inc.  All rights reserved.
* Copyright (c) 2022 - 2024 Advanced Micro Devices, Inc. All Rights Reserved.
* SPDX-License-Identifier: MIT
******************************************************************************/

/*****************************************************************************/
/**
*
* @file xscugic_intr.c
* @addtogroup scugic_api SCUGIC APIs
* @{
*
* The xscugic_intr.c file contains the interrupt processing for the driver for the
* Interrupt Controller. The interrupt processing is partitioned separately such
* that users are not required to use the provided interrupt processing. This
* file requires other files of the driver to be linked in also.
*
* The interrupt handler XScuGic_InterruptHandler uses an input argument which
* is an instance pointer to an interrupt controller driver such that multiple
* interrupt controllers can be supported. This handler requires the calling
* function to pass it the appropriate argument, so another level of indirection
* can be required.
*
* The interrupt processing is used by connecting the interrupt handler to
* the interrupt system. The handler does not save and restore the processor
* context but only handles the processing of the Interrupt Controller. The user
* is encouraged to supply their own interrupt handler when performance tuning is
* deemed necessary.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- ---------------------------------------------------------
* 1.00a drg  01/19/10 First release
* 1.01a sdm  11/09/11 XScuGic_InterruptHandler has changed correspondingly
*		      since the HandlerTable has now moved to XScuGic_Config.
* 3.00  kvn  02/13/15 Modified code for MISRA-C:2012 compliance.
* 3.10  mus  07/17/18 Updated XScuGic_InterruptHandler to fix array overrun
*                     reported by coverity tool. It fixes CR#1006344.
* 3.10  mus  07/17/18 Updated file to fix the various coding style issues
*                     reported by checkpatch. It fixes CR#1006344.
*
* </pre>
*
* @internal
*
* This driver assumes that the context of the processor has been saved prior to
* the calling of the Interrupt Controller interrupt handler and then restored
* after the handler returns. This requires either the running RTOS to save the
* state of the machine or a wrapper be used as the destination of the
* interrupt vector to save the state of the processor and restore the state
* after the interrupt handler returns.
*
******************************************************************************/

/***************************** Include Files *********************************/

#include "xil_types.h"
#include "xil_assert.h"
#include "xscugic.h"

/************************** Constant Definitions *****************************/

/**************************** Type Definitions *******************************/

/***************** Macros (Inline Functions) Definitions *********************/

/************************** Function Prototypes ******************************/

/************************** Variable Definitions *****************************/

/*****************************************************************************/
/**
* This function is the primary interrupt handler for the driver.  It must be
* connected to the interrupt source such that it is called when an interrupt of
* the interrupt controller is active. It will resolve which interrupts are
* active and enabled and call the appropriate interrupt handler. It uses
* the Interrupt Type information to determine when to acknowledge the interrupt.
* Highest priority interrupts are serviced first.
*
* This function assumes that an interrupt vector table has been previously
* initialized.  It does not verify that entries in the table are valid before
* calling an interrupt handler.
*
*
* @param	InstancePtr Pointer to the XScuGic instance.
*
* @return	None.
*
*
******************************************************************************/
void XScuGic_InterruptHandler(XScuGic *InstancePtr)
{

	u32 InterruptID;
#if !defined (GICv3)
	    u32 IntIDFull;
#endif
	    XScuGic_VectorTableEntry *TablePtr;

	    /* Assert that the pointer to the instance is valid
	     */
	    Xil_AssertVoid(InstancePtr != NULL);

	    /*
	     * Read the int_ack register to identify the highest priority
	     * interrupt ID and make sure it is valid. Reading Int_Ack will
	     * clear the interrupt in the GIC.
	     */
#if defined (GICv3)
	    InterruptID = XScuGic_get_IntID();
#else
	    IntIDFull = XScuGic_CPUReadReg(InstancePtr, XSCUGIC_INT_ACK_OFFSET);
	    InterruptID = IntIDFull & XSCUGIC_ACK_INTID_MASK;
#endif
	    if (XSCUGIC_MAX_NUM_INTR_INPUTS <= InterruptID) {
		goto IntrExit;
	    }

	    /*
	     * If the interrupt is shared, do some locking here if
	     * there are multiple processors.
	     */
	    /*
	     * If pre-eption is required:
	     * Re-enable pre-emption by setting the CPSR I bit for non-secure ,
	     * interrupts or the F bit for secure interrupts
	     */

	    /*
	     * If we need to change security domains, issue a SMC
		 * instruction here.
	     */

	    /*
	     * Execute the ISR. Jump into the Interrupt service routine
	     * based on the IRQSource. A software trigger is cleared by
	     *.the ACK.
	     */
	    TablePtr = &(InstancePtr->Config->HandlerTable[InterruptID]);
		if (TablePtr != NULL) {
			TablePtr->Handler(TablePtr->CallBackRef);
		}

IntrExit:
	    /*
	     * Write to the EOI register, we are all done here.
	     * Let this function return, the boot code will restore the stack.
	     */
#if defined (GICv3)
	   XScuGic_ack_Int(InterruptID);

#else
	    XScuGic_CPUWriteReg(InstancePtr, XSCUGIC_EOI_OFFSET, IntIDFull);
#endif
	    /*
	     * Return from the interrupt. Change security domains
	     * could happen here.
	     */
}
/** @} */
