source: soft/giet_vm/giet_kernel/sys_handler.c @ 437

///////////////////////////////////////////////////////////////////////////////////
// File     : sys_handler.c
// Date     : 01/04/2012
// Author   : alain greiner and joel porquet
// Copyright (c) UPMC-LIP6
///////////////////////////////////////////////////////////////////////////////////
// The sys_handler.c and sys_handler.h files are part of the GIET-VM nano-kernel.
// It define the syscall_vector[] (at the end of this file), as well as the 
// associated syscall handlers that are not related to peripherals.
// The syscall handlers for peripherals are defined in the drivers.c file.
///////////////////////////////////////////////////////////////////////////////////

#include <sys_handler.h>
#include <tty_driver.h>
#include <tim_driver.h>
#include <ioc_driver.h>
#include <nic_driver.h>
#include <fbf_driver.h>
#include <ctx_handler.h>
#include <fat32.h>
#include <utils.h>
#include <vmem.h>
#include <hard_config.h>
#include <giet_config.h>
#include <mapping_info.h>

#if !defined(SEG_BOOT_MAPPING_BASE) 
# error: You must define SEG_BOOT_MAPPING_BASE in the hard_config.h file
#endif

////////////////////////////////////////////////////////////////////////////
//    Initialize the syscall vector with syscall handlers
// Note: This array must be synchronised with the define in file stdio.h
////////////////////////////////////////////////////////////////////////////
const void * _syscall_vector[64] = 
{
    &_proc_xyp,            /* 0x00 */
    &_get_proctime,        /* 0x01 */
    &_tty_write,           /* 0x02 */
    &_tty_read,            /* 0x03 */
    &_timer_start,         /* 0x04 */
    &_timer_stop,          /* 0x05 */
    &_tty_get_lock,        /* 0x06 */
    &_tty_release_lock,    /* 0x07 */
    &_heap_info,           /* 0x08 */
    &_local_task_id,       /* 0x09 */
    &_global_task_id,      /* 0x0A */ 
    &_fb_cma_init,         /* 0x0B */
    &_fb_cma_write,        /* 0x0C */
    &_fb_cma_stop,         /* 0x0D */
    &_task_exit,           /* 0x0E */
    &_procs_number,        /* 0x0F */

    &_fb_sync_write,       /* 0x10 */
    &_fb_sync_read,        /* 0x11 */
    &_thread_id,           /* 0x12 */
    &_sys_ukn,             /* 0x13 */
    &_sys_ukn,             /* 0x14 */
    &_sys_ukn,             /* 0x15 */ 
    &_sys_ukn,             /* 0x16 */
    &_sys_ukn,             /* 0x17 */
    &_sys_ukn,             /* 0x18 */   
    &_context_switch,      /* 0x19 */
    &_vobj_get_vbase,      /* 0x1A */
    &_get_xy_from_ptr,     /* 0x1B */
    &_nic_cma_start,       /* 0x1C */
    &_nic_cma_stop,        /* 0x1D */
    &_nic_sync_read,       /* 0x1E */
    &_nic_sync_write,      /* 0x1F */

    &_fat_user_open,       /* 0x20 */
    &_fat_user_read,       /* 0x21 */
    &_fat_user_write,      /* 0x22 */
    &_fat_user_lseek,      /* 0x23 */
    &_fat_fstat,           /* 0x24 */
    &_fat_close,           /* 0x25 */
    &_sys_ukn,             /* 0x26 */
    &_sys_ukn,             /* 0x27 */
    &_sys_ukn,             /* 0x28 */
    &_sys_ukn,             /* 0x29 */
    &_sys_ukn,             /* 0x2A */
    &_sys_ukn,             /* 0x2B */
    &_sys_ukn,             /* 0x2C */
    &_sys_ukn,             /* 0x2D */
    &_sys_ukn,             /* 0x2E */
    &_sys_ukn,             /* 0x2F */

    &_sys_ukn,             /* 0x30 */
    &_sys_ukn,             /* 0x31 */
    &_sys_ukn,             /* 0x32 */
    &_sys_ukn,             /* 0x33 */
    &_sys_ukn,             /* 0x34 */
    &_sys_ukn,             /* 0x35 */ 
    &_sys_ukn,             /* 0x36 */
    &_sys_ukn,             /* 0x37 */
    &_sys_ukn,             /* 0x38 */   
    &_sys_ukn,             /* 0x39 */
    &_sys_ukn,             /* 0x3A */
    &_sys_ukn,             /* 0x3B */
    &_sys_ukn,             /* 0x3C */
    &_sys_ukn,             /* 0x3D */
    &_sys_ukn,             /* 0x3E */
    &_sys_ukn,             /* 0x3F */
};

//////////////////////////////////////////////////////////////////////////////
// function executed in case of undefined syscall
//////////////////////////////////////////////////////////////////////////////
void _sys_ukn() 
{
    _printf("\n\n[GIET ERROR] Undefined System Call / EPC = %x\n", _get_epc() );
    _exit();
}

//////////////////////////////////////////////////////////////////////////////
// This function returns the processor (x,y,p) identifiers.
//////////////////////////////////////////////////////////////////////////////
void _proc_xyp( unsigned int* x,
                unsigned int* y,
                unsigned int* p )
{
    unsigned int gpid = _get_procid();  // global processor index from CPO register

    *x = (gpid >> (Y_WIDTH + P_WIDTH)) & ((1<<X_WIDTH)-1);
    *y = (gpid >> P_WIDTH) & ((1<<Y_WIDTH)-1);
    *p = gpid & ((1<<P_WIDTH)-1);
}
////////////////////////////////////////////////////////////////////////////
// Task suicide... after printing a death message.
////////////////////////////////////////////////////////////////////////////
void _task_exit( char* string ) 
{
    unsigned int date       = _get_proctime();

    unsigned int gpid       = _get_procid();
    unsigned int cluster_xy = gpid >> P_WIDTH;
    unsigned int y          = cluster_xy & ((1<<Y_WIDTH)-1);
    unsigned int x          = cluster_xy >> Y_WIDTH;
    unsigned int lpid       = gpid & ((1<<P_WIDTH)-1);

    unsigned int task_id    = _get_context_slot(CTX_LTID_ID);

    // print death message
    _printf("\n[GIET] Exit task %d on processor[%d,%d,%d] at cycle %d"
            "\n       Cause : %s\n\n",
            task_id, x, y, lpid, date, string );

    // goes to sleeping state
    _set_context_slot(CTX_RUN_ID, 0);

    // deschedule
    _context_switch();
} 

//////////////////////////////////////////////////////////////////////////////
// returns in buffer argument the number of processors in the cluster
// specified by the cluster_id argument.
//////////////////////////////////////////////////////////////////////////////
unsigned int _procs_number(unsigned int  cluster_id, 
                           unsigned int* buffer) 
{
    mapping_header_t * header  = (mapping_header_t *)SEG_BOOT_MAPPING_BASE;
    mapping_cluster_t * cluster = _get_cluster_base(header);

    if ( cluster_id < X_SIZE * Y_SIZE ) 
    {
        *buffer = cluster[cluster_id].procs;
        return 0;
    }
    else 
    {
        return 1;
    }
}

/////////////////////////////////////////////////////////////////////////////
// Returns current task local index.
/////////////////////////////////////////////////////////////////////////////
unsigned int _local_task_id()
{
    return _get_context_slot(CTX_LTID_ID);
}

/////////////////////////////////////////////////////////////////////////////
// Returns current task global index.
/////////////////////////////////////////////////////////////////////////////
unsigned int _global_task_id()
{
    return _get_context_slot(CTX_GTID_ID);
}

/////////////////////////////////////////////////////////////////////////////
// Returns current thread index.
/////////////////////////////////////////////////////////////////////////////
unsigned int _thread_id()
{
    return _get_context_slot(CTX_TRDID_ID);
}

/////////////////////////////////////////////////////////////////////////////
// This function writes in res_vobj a pointer on a vobj 
// identified by the (vspace_name / vobj_name ) couple.
// returns 0 if success, >0 if not found
/////////////////////////////////////////////////////////////////////////////
int _get_vobj( char*             vspace_name, 
               char*             vobj_name, 
               mapping_vobj_t**  res_vobj ) 
{
    mapping_header_t * header = (mapping_header_t *)SEG_BOOT_MAPPING_BASE;
    mapping_vspace_t * vspace = _get_vspace_base(header);
    mapping_vobj_t * vobj     = _get_vobj_base(header);

    unsigned int vspace_id;
    unsigned int vobj_id;

    // scan vspaces 
    for (vspace_id = 0; vspace_id < header->vspaces; vspace_id++) 
    {
        if (_strncmp( vspace[vspace_id].name, vspace_name, 31) == 0) 
        {
            // scan vobjs
            for (vobj_id = vspace[vspace_id].vobj_offset; 
                 vobj_id < (vspace[vspace_id].vobj_offset + vspace[vspace_id].vobjs); 
                 vobj_id++) 
            {
                if (_strncmp(vobj[vobj_id].name, vobj_name, 31) == 0) 
                {
                    *res_vobj = &vobj[vobj_id];
                    return 0;
                }
            } 
        }
    } 
    return 1;    //not found 
}

/////////////////////////////////////////////////////////////////////////////
// This function writes in vobj_vbase the virtual base address of a vobj 
// identified by the (vspace_name / vobj_name ) couple.
// returns 0 if success, >0 if not found
/////////////////////////////////////////////////////////////////////////////
unsigned int _vobj_get_vbase( char*         vspace_name,
                              char*         vobj_name,
                              unsigned int* vobj_vbase ) 
{
    mapping_vobj_t* res_vobj;
    unsigned int    ret;
    if ((ret = _get_vobj(vspace_name, vobj_name, &res_vobj))) 
    {
        return ret;
    }
    *vobj_vbase = res_vobj->vbase;
    return 0;
}

/////////////////////////////////////////////////////////////////////////////
// This function writes in vobj_length the length of a vobj 
// identified by the (vspace_name / vobj_name ) couple.
// returns 0 if success, >0 if not found
/////////////////////////////////////////////////////////////////////////////
unsigned int _vobj_get_length( char*         vspace_name, 
                               char*         vobj_name,
                               unsigned int* vobj_length ) 
{
    mapping_vobj_t * res_vobj;
    unsigned int ret;
    if ((ret = _get_vobj(vspace_name, vobj_name, &res_vobj))) 
    {
        return ret;
    }
    *vobj_length = res_vobj->length;
    return 0;
}

/////////////////////////////////////////////////////////////////////////////
// This function returns in the (x,y) arguments the coordinates of the 
// where is mapped the ptr virtual address. It use the _get_context_slot()
// function to get the calling task page table, and uses the _v2p_translate()
// function to obtain the physical address. 
// returns 0 if success, > 0 if ptr not mapped in the calling task vspace.
/////////////////////////////////////////////////////////////////////////////

unsigned int _get_xy_from_ptr( void*         ptr,
                               unsigned int* px,
                               unsigned int* py )
{
    unsigned int ret;
    unsigned int ppn;
    unsigned int flags;
    unsigned int vpn  = (((unsigned int)ptr)>>12);
    
    // get the page table pointer
    page_table_t* pt = (page_table_t*)_get_context_slot( CTX_PTAB_ID ); 

    // compute the physical address
    if ( (ret = _v2p_translate( pt, vpn, &ppn, &flags )) )
    {
        return ret;
    }

    *px = (ppn>>24) & 0xF;
    *py = (ppn>>20) & 0xF;
    return 0;
}

////////////////////////////////////////////////////////////////////////////
// This sysrem function deschedule the requestint task.
// It mask interrupts before calling the _ctx_switch, and restore it
// when the task is rescheduled.
////////////////////////////////////////////////////////////////////////////
void _context_switch() 
{
    unsigned int save_sr;

    _it_disable( &save_sr );
    _ctx_switch();
    _it_restore( &save_sr );
}

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