source: trunk/kernel/kern/printk.c @ 40

/*
 * printk.c - Kernel Log & debug messages 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_irqmask.h>
#include <hal_special.h>
#include <dev_txt.h>
#include <remote_spinlock.h>
#include <cluster.h>
#include <chdev.h>
#include <printk.h>

///////////////////////////////////////////////////////////////////////////////////
//      Extern variables
///////////////////////////////////////////////////////////////////////////////////

extern chdev_t            txt0_chdev;        // allocated in kernel_init.c

/////////////////////////////////////
uint32_t snprintf( char     * string,
                   uint32_t   length,
                   char     * format, ... )
{

#define TO_STREAM(x) do { string[ps] = (x); ps++; if(ps==length) return -1; } while(0);

    va_list    args;      // printf arguments
    uint32_t   ps;        // write pointer to the string buffer

    ps = 0;   
    va_start( args , format );

xprintf_text:

    while ( *format != 0 ) 
    {

        if (*format == '%')   // copy argument to string
        {
            format++;
            goto xprintf_arguments;
        }
        else                  // copy one char to string
        {
            TO_STREAM( *format );
            format++;
        }
    }

    va_end( args );
    
    // add terminating NUL chracter
    TO_STREAM( 0 );
    return ps;

xprintf_arguments:

    {
        char              buf[30];    // buffer to display one number
        char *            pbuf;       // pointer on first char to display
        uint32_t          len = 0;    // number of char to display
        static const char HexaTab[] = "0123456789ABCDEF";
        uint32_t          i;
        
        // Ignore fields width and precision 
        for ( ; (*format >= '0' && *format <= '9') || (*format == '.') ; format++ );

        switch (*format) 
        {
            case ('c'):             // char conversion 
            {
                int val = va_arg( args, int );
                buf[0] = val;
                pbuf   = buf;
                len    = 1;
                break;
            }
            case ('d'):             // decimal signed integer
            {
                int val = va_arg( args, int );
                if (val < 0) 
                {
                    TO_STREAM( '-' );
                    val = -val;
                }
                for(i = 0; i < 10; i++) 
                {

                    buf[9 - i] = HexaTab[val % 10];
                    if (!(val /= 10)) break;
                }
                len =  i + 1;
                pbuf = &buf[9 - i];
                break;
            }
            case ('u'):             // decimal unsigned integer
            {
                uint32_t val = va_arg( args, uint32_t );
                for(i = 0; i < 10; i++) 
                {
                    buf[9 - i] = HexaTab[val % 10];
                    if (!(val /= 10)) break;
                }
                len =  i + 1;
                pbuf = &buf[9 - i];
                break;
            }
            case ('x'):             // 32 bits hexadecimal 
            case ('l'):             // 64 bits hexadecimal 
            {
                uint32_t       imax;
                uint64_t val;
                
                if ( *format == 'l' )   // 64 bits
                {
                    val = va_arg( args, uint64_t);
                    imax = 16;
                }
                else                    // 32 bits
                {
                    val = va_arg( args, uint32_t);
                    imax = 8;
                }
                
                TO_STREAM( '0' );
                TO_STREAM( 'x' );
                
                for(i = 0; i < imax; i++) 
                {
                    buf[(imax-1) - i] = HexaTab[val % 16];
                    if (!(val /= 16))  break;
                }
                len =  i + 1;
                pbuf = &buf[(imax-1) - i];
                break;
            }
            case ('s'):             /* string */
            {
                char* str = va_arg( args, char* );
                while (str[len]) { len++; }
                pbuf = str;
                break;
            }
            default:       // unsupported argument type
            {
                return -1;
            }
        }  // end switch on  argument type

        format++;

        // copy argument to string
        for( i = 0 ; i < len ; i++ )
        {
            TO_STREAM( pbuf[i] );
        }
        
        goto xprintf_text;
    }
} // end xprintf()

///////////////////////////////////////////////////////////////////////////////////
// This static function is called by kernel_printf() to display a string on the
// TXT channel defined by the <channel> argument. 
// The access mode is defined by the <busy> argument:
// - if <busy> is true, it uses the dev_txt_sync_write() function, that takes the
//   TXT lock, and call directly the relevant TXT driver, without descheduling.
// - if <busy is false, it uses the dev_txt_write() function, that register the
//   write buffer in the relevant TXT chdev queue, and uses a descheduling policy.
///////////////////////////////////////////////////////////////////////////////////
// @ channel  : TXT channel.
// @ busy     : TXT device acces mode (busy waiting if non zero).
// @ buf      : buffer containing the characters.
// @ nc       : number of characters.
// return 0 if success / return -1 if TTY0 busy after 10000 retries.
///////////////////////////////////////////////////////////////////////////////////
static error_t txt_write( uint32_t  channel,
                          uint32_t  busy,
                          char    * buffer,
                          uint32_t  count )
{
    if( busy ) return dev_txt_sync_write( channel , buffer , count );
    else       return dev_txt_write( channel , buffer , count );
}  

//////////////////////////////////////////////////////////////////////////////////////
// This static function is called by printk() and user_printk() to build
// a formated string.
//////////////////////////////////////////////////////////////////////////////////////
// @ channel   : channel index.
// @ busy      : TXT device access mode (busy waiting if non zero).
// @ format    : printf like format.
// @ args      : format arguments.
//////////////////////////////////////////////////////////////////////////////////////
static void kernel_printf( uint32_t   channel,
                           uint32_t   busy,
                           char     * format, 
                           va_list  * args ) 
{

printf_text:

    while (*format) 
    {
        uint32_t i;
        for (i = 0 ; format[i] && (format[i] != '%') ; i++);
        if (i) 
        {
            txt_write( channel, busy, format, i );
            format += i;
        }
        if (*format == '%') 
        {
            format++;
            goto printf_arguments;
        }
    }

    return;

printf_arguments:

    {
        char      buf[20];
        char    * pbuf = NULL;
        uint32_t  len  = 0;
        static const char HexaTab[] = "0123456789ABCDEF";
        uint32_t i;

        switch (*format++) 
        {
            case ('c'):             /* char conversion */
            {
                int val = va_arg( *args , int );
                len = 1;
                buf[0] = val;
                pbuf = &buf[0];
                break;
            }
            case ('d'):             /* 32 bits decimal signed  */
            {
                int val = va_arg( *args , int );
                if (val < 0) 
                {
                    val = -val;
                    txt_write( channel, busy, "-" , 1 );
                }
                for(i = 0; i < 10; i++) 
                {
                    buf[9 - i] = HexaTab[val % 10];
                    if (!(val /= 10)) break;
                }
                len =  i + 1;
                pbuf = &buf[9 - i];
                break;
            }
            case ('u'):             /* 32 bits decimal unsigned  */
            {
                uint32_t val = va_arg( *args , uint32_t );
                for(i = 0; i < 10; i++) 
                {
                    buf[9 - i] = HexaTab[val % 10];
                    if (!(val /= 10)) break;
                }
                len =  i + 1;
                pbuf = &buf[9 - i];
                break;
            }
            case ('x'):             /* 32 bits hexadecimal unsigned */
            {
                uint32_t val = va_arg( *args , uint32_t );
                txt_write( channel, busy, "0x" , 2 );
                for(i = 0; i < 8; i++) 
                {
                    buf[7 - i] = HexaTab[val & 0xF];
                    if (!(val = (val>>4)))  break;
                }
                len =  i + 1;
                pbuf = &buf[7 - i];
                break;
            }
            case ('X'):             /* 32 bits hexadecimal unsigned  on 10 char */
            {
                uint32_t val = va_arg( *args , uint32_t );
                txt_write( channel, busy, "0x" , 2 );
                for(i = 0; i < 8; i++) 
                {
                    buf[7 - i] = HexaTab[val & 0xF];
                    val = (val>>4);
                }
                len =  8;
                pbuf = buf;
                break;
            }
            case ('l'):            /* 64 bits hexadecimal unsigned */
            {
                uint64_t val = va_arg( *args , uint64_t );
                txt_write( channel, busy, "0x" , 2 );
                for(i = 0; i < 16; i++) 
                {
                    buf[15 - i] = HexaTab[val & 0xF];
                    if (!(val = (val>>4)))  break;
                }
                len =  i + 1;
                pbuf = &buf[15 - i];
                break;
            }
            case ('L'):           /* 64 bits hexadecimal unsigned on 18 char */ 
            {
                uint64_t val = va_arg( *args , uint64_t );
                txt_write( channel, busy, "0x" , 2 );
                for(i = 0; i < 16; i++) 
                {
                    buf[15 - i] = HexaTab[val & 0xF];
                    val = (val>>4);
                }
                len =  16;
                pbuf = buf;
                break;
            }
            case ('s'):             /* string */
            {
                char* str = va_arg( *args , char* );
                while (str[len]) 
                {
                    len++;
                }
                pbuf = str;
                break;
            }
            default:
            {
                txt_write( channel , busy,
                           "\n[PANIC] in kernel_printf() : illegal format\n", 45 );
            }
        }

        if( pbuf != NULL ) txt_write( channel, busy, pbuf, len );
        
        goto printf_text;
    }

}  // end kernel_printf()

/////////////////////////////////
void printk( char * format , ...)
{
    va_list       args;
    uint32_t      save_sr;

    // get extended pointer on remote TXT0 chdev lock
    xptr_t  txt0_lock_xp = XPTR( LOCAL_CLUSTER->io_cxy , &txt0_chdev.wait_lock );

    // get TXT0 lock in busy waiting mode
    remote_spinlock_lock_busy( txt0_lock_xp , &save_sr );

    // call kernel_printf in busy waiting mode
    va_start( args , format );
    kernel_printf( 0 , 1 , format , &args );
    va_end( args );

    // release lock
    remote_spinlock_unlock_busy( txt0_lock_xp , save_sr );
}

//////////////////////////////////////
void user_printk( char * format , ...)
{
    va_list   args;

    // get calling thread TXT channel TODO
    uint32_t channel = 0;

   // call kernel_printf in descheduling mode
    va_start( args , format );
    kernel_printf( channel, 0 , format , &args );
    va_end( args );
}

///////////////////////////////////////////
inline void assert( bool_t       condition,
                    const char * function_name,
                    char       * string )
{
    if( condition == false )
    {
        printk("\n[PANIC] in %s : %s\n" , function_name , string );
        hal_core_sleep();
    }
}


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