/*
 * dev_icu.c - ICU (Interrupt Controler Unit) generic device API implementation.
 *
 * Authors   Alain Greiner  (2016)
 *
 * Copyright (c) UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-MKH.
 *
 * ALMOS-MKH is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-MKH is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <hal_types.h>
#include <hal_special.h>
#include <chdev.h>
#include <thread.h>
#include <cluster.h>
#include <printk.h>
#include <memcpy.h>
#include <spinlock.h>
#include <soclib_xcu.h>
#include <dev_icu.h>

/////////////////////////////////////////////////////////////////////////////////////////
// Extern global variables
/////////////////////////////////////////////////////////////////////////////////////////

extern chdev_directory_t  chdev_dir;         // allocated in kernel_init.c

extern chdev_pic_input_t  chdev_pic_input;   // allocated in kernel_init.c

/////////////////////////////////
void dev_icu_init( chdev_t * icu,
                   uint32_t  hwi_nr,
                   uint32_t  wti_nr,
                   uint32_t  pti_nr )
{
    // set chdev name
    snprintf( icu->name , 16 , "icu_%x" , local_cxy );

    // set ICU chdev extension fields
    icu->ext.icu.hwi_nr     = hwi_nr;
    icu->ext.icu.wti_nr     = wti_nr;
    icu->ext.icu.pti_nr     = pti_nr;
    icu->ext.icu.wti_bitmap = 0;
    spinlock_init( &icu->ext.icu.wti_lock );

    // get implementation
    uint32_t impl = icu->impl;

    // call the relevant driver init function
    if( impl == IMPL_ICU_XCU )
    {
        uint32_t  lid;
        for( lid = 0 ; lid < LOCAL_CLUSTER->cores_nr ; lid++ )
        {
            soclib_xcu_init( icu , lid );
        }
    }
    else
    {
        assert( false , __FUNCTION__ , "undefined ICU implementation" );
    }
}

/////////////////////////////////////////////////////////////////////////////////////
// This static function check the irq_type / irq_index arguments.
// It is called by the dev_icu_enable_irq() & dev_icu_disable_irq() functions.
/////////////////////////////////////////////////////////////////////////////////////
static inline void dev_icu_check_irq( chdev_t  * icu,
                                      uint32_t   irq_type,
                                      uint32_t   irq_index )
{
    if( irq_type == HWI_TYPE )
    {
        if( irq_index >= icu->ext.icu.hwi_nr )
        {
            printk("\n[PANIC] in %s : illegal HWI index = %d / max = %d\n",
                   __FUNCTION__ , irq_index , icu->ext.icu.hwi_nr );
            hal_core_sleep();
        }
    }
    else if( irq_type == WTI_TYPE )
    {
        if( irq_index >= icu->ext.icu.wti_nr )
        {
            printk("\n[PANIC] in %s : illegal WTI index = %d / max = %d\n",
                   __FUNCTION__ , irq_index , icu->ext.icu.wti_nr );
            hal_core_sleep();
        }
    }
    else  //  irq_type == PTI_TYPE
    {
        if( irq_index >= icu->ext.icu.pti_nr )
        {
            printk("\n[PANIC] in %s : illegal PTI index = %d / max = %d\n",
                   __FUNCTION__ , irq_index , icu->ext.icu.pti_nr );
            hal_core_sleep();
        }
    }
}

////////////////////////////////////////
void dev_icu_enable_irq( lid_t      lid,
                         uint32_t   irq_type,
                         uint32_t   irq_index,
                         chdev_t  * src_chdev )
{
    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    // check IRQ type and index
    dev_icu_check_irq( icu , irq_type , irq_index );

    // call implementation specific ICU driver to enable IRQ
    if( icu->impl == IMPL_ICU_XCU )
    {
         soclib_xcu_enable_irq( icu , 1<<irq_index , irq_type , lid );
    }

    // This is only done for an HWI, or for a WTI that is not an IPI
    if( (irq_type != PTI_TYPE) && (src_chdev != NULL) )
    {
        // get selected core local pointer, and register
        // source chdev pointer in relevant interrupt vector
        core_t * core = &LOCAL_CLUSTER->core_tbl[lid];
        core_set_irq_vector_entry( core , irq_type , irq_index , src_chdev );

        // (3) register IRQ type and index in source chdev descriptor
        src_chdev->irq_type = irq_type;
        src_chdev->irq_id   = irq_index;
    }
}

/////////////////////////////////////////
void dev_icu_disable_irq( lid_t      lid,
                          uint32_t   irq_type,
                          uint32_t   irq_index )
{
    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    // check IRQ type and index
    dev_icu_check_irq( icu , irq_type , irq_index );

    // call the implementation specific ICU driver to disable IRQ
    if( icu->impl == IMPL_ICU_XCU )
    {
        soclib_xcu_disable_irq( icu , 1<<irq_index , irq_type , lid );
    }

    // This is only done for HWI or WTI that are not IPI
    if( irq_type != PTI_TYPE )
    {
        // get selected remote core local pointer, and remove
        // the source chdev xptr from relevant interrupt vector
        core_t * core = &LOCAL_CLUSTER->core_tbl[lid];
        core_set_irq_vector_entry( core , irq_type , irq_index , NULL );
    }
}

///////////////////////////////////////
void dev_icu_get_masks( lid_t      lid,
                        uint32_t * hwi_mask,
                        uint32_t * wti_mask,
                        uint32_t * pti_mask )
{
    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    if( icu->impl == IMPL_ICU_XCU )
    {
        soclib_xcu_get_masks( icu , lid , hwi_mask , wti_mask , pti_mask );
    }
}

//////////////////////////////////////////////
void dev_icu_set_period( uint32_t   pti_index,
                         uint32_t   period )
{
    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    // check PTI index
    assert( (pti_index < icu->ext.icu.pti_nr) , __FUNCTION__ , "illegal PTI index" );

    // call the implementation specific driver ICU to set period
    if( icu->impl == IMPL_ICU_XCU )
    {
        soclib_xcu_set_period( icu , pti_index , period );
    }
}

////////////////////////////////////////////
void dev_icu_ack_timer( uint32_t pti_index )
{
    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    // check PTI index
    assert( (pti_index < icu->ext.icu.pti_nr) , __FUNCTION__ , "illegal PTI index" );

    // call the implementation specific driver ICU to acknowledge PTI IRQ
    if( icu->impl == IMPL_ICU_XCU )
    {
        soclib_xcu_ack_timer( icu , pti_index );
    }
}

////////////////////////////////////
void dev_icu_send_ipi( cxy_t    cxy,
                       lid_t    lid )
{
    // check arguments
    cluster_t * cluster  = LOCAL_CLUSTER;
    uint32_t    y_width  = cluster->y_width;
    uint32_t    x_size   = cluster->x_size;
    uint32_t    y_size   = cluster->y_size;
    uint32_t    cores_nr = cluster->cores_nr;
    uint32_t    x = cxy >> y_width;
    uint32_t    y = cxy & ((1<<y_width)-1);

    assert( ((x < x_size) && (y < y_size)) , __FUNCTION__ , "illegal cluster identifier" );

    assert( (lid < cores_nr) , __FUNCTION__ , "illegal core local index" );

    // get extended pointer on target ICU chdev
    xptr_t icu_xp = chdev_dir.icu[cxy];

     // get target ICU cluster and local pointer
    cxy_t     icu_cxy = GET_CXY( icu_xp );
    chdev_t * icu_ptr = (chdev_t *)GET_PTR( icu_xp );

    // get implementation from remote ICU chdev
    uint32_t impl = hal_remote_lw( XPTR( icu_cxy , &icu_ptr->impl ) );

    // call the implementation specific ICU driver to send IPI
    if( impl == IMPL_ICU_XCU )
    {
        soclib_xcu_send_ipi( icu_xp , lid );
    }
}

//////////////////////////
void dev_icu_irq_handler()
{
    uint32_t   hwi_status;   // HWI index + 1  / no pending HWI if 0
    uint32_t   wti_status;   // WTI index + 1  / no pending WTI if 0
    uint32_t   pti_status;   // PTI index + 1  / no pending PTI if 0
    chdev_t  * src_chdev;    // pointer on source chdev descriptor
    uint32_t   index;        // IRQ index

    core_t   * core = CURRENT_CORE;

    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    // call the implementation specific ICU driver
    // to return highest priority pending IRQ of each type
    if( icu->impl == IMPL_ICU_XCU )
    {
        soclib_xcu_get_status( icu , core->lid , &hwi_status , &wti_status , &pti_status );
    }

    // analyse ICU status and handle up to 3 pending IRQ (one WTI, one HWI, one PTI)

    if( wti_status )          // pending WTI
    {
        index = wti_status - 1;

        if( index < LOCAL_CLUSTER->cores_nr )   // it is an IPI
        {
            assert( (index == core->lid) , __FUNCTION__ , "illegal IPI index" );

            // TODO acknowledge WTI [AG]

            // TODO force scheduling [AG]
        }
        else                                    // it is an external device
        {
            // get pointer on IRQ source chdev
            src_chdev = core->wti_vector[index];

            if( src_chdev == NULL )        // strange, but not fatal => disable IRQ
            {
                printk("\n[WARNING] in %s : no handler for WTI %d on core %d in cluster %x\n",
                       __FUNCTION__ , index , core->lid , local_cxy );
                core->spurious_irqs ++;
                dev_icu_disable_irq( core->lid , WTI_TYPE , index );
            }
            else                                 // call relevant ISR
            {
                icu_dmsg("\n[INFO] %s received WTI : index = %d for cpu %d in cluster %d\n",
                         __FUNCTION__ , index , core->lid , local_cxy );

                // call ISR
                src_chdev->isr( src_chdev );
            }
        }
    }

    if( hwi_status )      // pending HWI
    {
        index = hwi_status - 1;

        // get pointer on IRQ source chdev
        src_chdev = core->hwi_vector[index];

        if( src_chdev == NULL )        // strange, but not fatal => disable IRQ
        {
            printk("\n[WARNING] in %s : no handler for HWI %d on core %d in cluster %x\n",
                   __FUNCTION__ , index , core->lid , local_cxy );
            core->spurious_irqs ++;
            dev_icu_disable_irq( core->lid , HWI_TYPE , index );
        }
        else                    // call relevant ISR
        {
            icu_dmsg("\n[INFO] %s received HWI : index = %d for cpu %d in cluster %d\n",
                     __FUNCTION__ , index , core->lid , local_cxy );

            // call ISR
            src_chdev->isr( src_chdev );
        }
    }

    if( pti_status )      // pending PTI
    {
        index = pti_status - 1;

        icu_dmsg("\n[INFO] %s received PTI : index = %d for cpu %d in cluster %d\n",
                 __FUNCTION__ , index , core->lid , local_cxy );

        // acknowledge PTI
        dev_icu_ack_timer( index );

        if( index < LOCAL_CLUSTER->cores_nr )  // its a TICK event
        {
            // TODO execute all actions related to TICK event
            core_clock( core );
        }
        else
        {
            printk("\n[WARNING] in %s : no handler for PTI %d on core %d in cluster %x\n",
                   __FUNCTION__ , index , core->lid , local_cxy );
            core->spurious_irqs ++;
            dev_icu_disable_irq( core->lid , PTI_TYPE , index );
        }
    }
}

////////////////////////////
uint32_t dev_icu_wti_alloc()
{
    // get local pointer on local ICU chdev
    xptr_t    icu_xp = chdev_dir.icu[local_cxy];
    chdev_t * icu    = (chdev_t *)GET_PTR( icu_xp );

    // get bitmap pointer, lock pointer, and size
    uint32_t   * bitmap = &icu->ext.icu.wti_bitmap;
    spinlock_t * lock   = &icu->ext.icu.wti_lock;
    uint32_t     size   =  icu->ext.icu.wti_nr;

    // get lock protecting WTI allocator
    spinlock_lock( lock );

    // get first free mailbox index
    uint32_t index = (uint32_t)bitmap_ffc( bitmap , size );

    // set bitmap entry if found
    if( index < size ) bitmap_set( bitmap , index );

    // release lock
    spinlock_unlock( lock );

    return index;
}

//////////////////////////////////////////
void dev_icu_wti_release( uint32_t index )
{
    // get pointer on local ICU chdev descriptor
    xptr_t    icu_xp  = chdev_dir.icu[local_cxy];
    chdev_t * icu_ptr = (chdev_t *)GET_PTR( icu_xp );

    // get bitmap pointer, lock, and size
    bitmap_t   * bitmap = &icu_ptr->ext.icu.wti_bitmap;
    spinlock_t * lock   = &icu_ptr->ext.icu.wti_lock;
    uint32_t     size   =  icu_ptr->ext.icu.wti_nr;

    // check index
    assert( (index < size) , __FUNCTION__ , "illegal WTI index" );

    // get lock protecting WTI allocator
    spinlock_lock( lock );

    // clear bitmap entry
    bitmap_clear( bitmap , index );

    // release lock
    spinlock_unlock( lock );
}

//////////////////////////////////////////////
uint32_t * dev_icu_wti_ptr( uint32_t  wti_id )
{
    uint32_t *  wti_ptr = NULL;

    // get pointer on local ICU chdev descriptor
    xptr_t    icu_xp  = chdev_dir.icu[local_cxy];
    chdev_t * icu     = (chdev_t *)GET_PTR( icu_xp );

    // call implementation specific ICU driver
    if( icu->impl == IMPL_ICU_XCU )
    {
        wti_ptr = soclib_xcu_wti_ptr( icu , wti_id );
    }

    return wti_ptr;
}