source: trunk/kernel/devices/dev_dma.c @ 40

/*
 * dev_dma.c - DMA (Interrupt Controler Unit) generic device API implementation.
 *
 * Authors   Alain Greiner  (2017)
 *
 * 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 PARTDMALAR 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_dma.h>
#include <dev_dma.h>
#include <soclib_dma.h>

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

extern chdev_directory_t  chdev_dir;         // allocated in kernel_init.c

extern chdev_icu_input_t  chdev_icu_input;   // allocated in kernel_init.c

////////////////////////////////////
void dev_dma_init( chdev_t * chdev )
{
    // get implementation & channel from DMA chdev descriptor
    uint32_t impl    = chdev->impl;
    uint32_t channel = chdev->channel;

    // set chdev name
    snprintf( chdev->name , 16 , "dma_%d_%x" , channel , local_cxy );

    // set field "cmd", "isr", and call the relevant driver init function
    if( impl == IMPL_DMA_SCL )
    {
        chdev->cmd = &soclib_dma_cmd;
        chdev->isr = &soclib_dma_isr;
        soclib_dma_init( chdev );
    }
    else
    {
        assert( false , __FUNCTION__ , "undefined DMA implementation" );
    }

    // get DMA HWI IRQ index
    uint32_t hwi_id = chdev_icu_input.dma[channel];

    // enable HWI IRQ in local ICU, and update  interrupt vector
    // the selected core is defined by the DMA channel index
    dev_icu_enable_irq( channel , HWI_TYPE , hwi_id , chdev );

    // create server thread
    thread_t * new_thread;
    error_t    error;

    error = thread_kernel_create( &new_thread,
                                  THREAD_DEV,
                                  &chdev_sequencial_server,
                                  chdev,
                                  cluster_select_local_core() );
    if( error )
    {
        assert( false , __FUNCTION__ , "cannot create server thread" );
    }

    // initialises server field in DMA chdev descriptor
    chdev->server = new_thread;
    
    // start server thread
    thread_unblock( XPTR( local_cxy , new_thread ) , THREAD_BLOCKED_GLOBAL );
    
} // dev_dma_init()

////////////////////////////////////////////////
error_t dev_dma_remote_memcpy( xptr_t    dst_xp,
                               xptr_t    src_xp,
                               uint32_t  size )
{
    thread_t * this = CURRENT_THREAD;

    dma_dmsg("\n[INFO] %s : enters for thread %x / dst = %l /src = %l / size = %x\n",
              __FUNCTION__ , this->trdid , dst_xp , src_xp , size );

    // select DMA channel corresponding to core lid
    uint32_t channel = this->core->lid;

    // get extended pointer on selected DMA chdev descriptor
    xptr_t  dev_xp = chdev_dir.dma[channel];

    assert( (dev_xp != XPTR_NULL) , __FUNCTION__ , "undefined DMA chdev descriptor" );

    // register command in calling thread descriptor
    this->command.dma.dev_xp  = dev_xp;
    this->command.dma.dst_xp  = dst_xp;
    this->command.dma.src_xp  = src_xp;
    this->command.dma.size    = size;

    // register client thread in waiting queue, activate server thread
    // block client thread on THREAD_BLOCKED_IO and deschedule.
    // it is re-activated by the ISR signaling IO operation completion.
    chdev_register_command( dev_xp , this );

    dma_dmsg("\n[INFO] %s : completes for thread %x / error = %d\n", 
             __FUNCTION__ ,  this->trdid , this->command.dma.error );

    // return I/O operation status from calling thread descriptor
    return this->command.dma.error;  

}  // dev_dma_remote_memcpy()