source: trunk/kernel/kern/device.c @ 3

/*
 * device.c - device descriptor operations 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 <almos_config.h>
#include <hal_types.h>
#include <hal_special.h>
#include <boot_info.h>
#include <xlist.h>
#include <kmem.h>
#include <thread.h>
#include <rpc.h>
#include <device.h>

////////////////////////////////////////////////////////////////////////////////////
// This array defines printable strings for devices functionnal types.
////////////////////////////////////////////////////////////////////////////////////

char * device_func_str[DEV_FUNC_NR] = 
{
        "RAM",
        "ROM",
        "TXT",
    "FBF",
    "IOB",
    "IOC",
    "MMC",
    "MWR",
    "NIC",
    "CMA",
    "XCU",
    "PIC"
};

////////////////////////////////////////
xptr_t device_alloc( boot_info_t * info,
                     bool_t        is_local )
{
    xptr_t     dev_xp;
    device_t * dev_ptr;
    uint32_t   index;
    uint32_t   x;
    uint32_t   y;
    cxy_t      target_cxy;
    kmem_req_t req;
    error_t    error;

    if( is_local )  // forced local allocation
    {
        req.type   = KMEM_DEVICE;
        req.flags  = AF_ZERO;
        dev_ptr    = (device_t *)kmem_alloc( &req );

        if( dev_ptr == NULL ) return XPTR_NULL;
        else                  return ( XPTR( local_cxy , dev_ptr ) );
    }
    else            // likely remote allocation
    {
        // select (pseudo-randomly) a target cluster
        index      = ( hal_time_stamp() + hal_get_gid() ) % (info->x_size * info->y_size);
        x          = index / info->y_size;    
        y          = index % info->y_size;
        target_cxy = (x<<info->y_width) + y;

        if( target_cxy == local_cxy )   // local allocation
        {
            req.type   = KMEM_DEVICE;
            req.flags  = AF_ZERO;
            dev_ptr    = (device_t *)kmem_alloc( &req );

            if( dev_ptr == NULL ) return XPTR_NULL;
            else                  return ( XPTR( local_cxy , dev_ptr ) );
        }
        else                          // remote allocation
        {
            rpc_device_alloc_client( target_cxy , &dev_xp , &error );
            if( error ) return XPTR_NULL;
            else        return ( dev_xp );
             
        }
    }   
} // end device_alloc()


/////////////////////////////////////
void device_init( xptr_t      device,
                  uint32_t    func,
                  uint32_t    impl,
                  uint32_t    channel,
                  uint32_t    is_rx,
                  xptr_t      base,
                  uint32_t    size )
{
    // get device cluster and local pointer
    cxy_t      cxy = GET_CXY( device );
    device_t * ptr = (device_t *)GET_PTR( device );

    // initialize waiting threads queue and associated lock
    remote_spinlock_init( XPTR( cxy , &ptr->wait_lock ) );
    xlist_root_init( XPTR( cxy , &ptr->wait_root ) );

    // initialize basic attributes
    hal_remote_sw ( XPTR( cxy , &ptr->func    ) , (uint32_t)func    );
    hal_remote_sw ( XPTR( cxy , &ptr->impl    ) , (uint32_t)impl    );
    hal_remote_sw ( XPTR( cxy , &ptr->channel ) , (uint32_t)channel );
    hal_remote_sw ( XPTR( cxy , &ptr->is_rx   ) , (uint32_t)is_rx   );
    hal_remote_swd( XPTR( cxy , &ptr->base    ) , (uint64_t)base    ); 
    hal_remote_sw ( XPTR( cxy , &ptr->size    ) , (uint64_t)size    ); 

}  // end device_init()

////////////////////////////////////////////////
void device_register_command( xptr_t     xp_dev,
                              thread_t * thread )
{
    thread_t * thread_ptr = CURRENT_THREAD;

    // get device descriptor cluster and local pointer
    cxy_t      dev_cxy = GET_CXY( xp_dev );
    device_t * dev_ptr = (device_t *)GET_PTR( xp_dev );

    // build extended pointers on client thread xlist and device root
    xptr_t  xp_list = XPTR( local_cxy , &thread_ptr->wait_list );
    xptr_t  xp_root = XPTR( dev_cxy , &dev_ptr->wait_root );

    // get lock protecting queue
    remote_spinlock_lock( XPTR( dev_cxy , &dev_ptr->wait_lock ) );

    // register client thread in waiting queue 
    xlist_add_last( xp_root , xp_list );

    // unblock server thread
    thread_unblock( XPTR( dev_cxy , &dev_ptr->server ) , THREAD_BLOCKED_DEV_QUEUE );

    // release lock
    remote_spinlock_unlock( XPTR( dev_cxy , &dev_ptr->wait_lock ) );

    // client thread goes to blocked state and deschedule
    thread_block( thread_ptr , THREAD_BLOCKED_IO );
    sched_yield();

}  // end device register_command()