l1.c

上传linux-jx2410的源代码

                /* type mismatch */
		va_end( al );
		DUMP_RESP;
                return -1;
            }
            bufptr = va_arg( al, char* ); argno++;
            strcpy( (char *)bufptr, (char *)&(resp[index]) );
            /* include terminating null */
            index += (strlen( &(resp[index]) ) + 1);
            break;

          default:
	    if( (l1_fld_t & L1_ARG_UNKNOWN) == L1_ARG_UNKNOWN )
	    {
		int *arglen;
		
		arglen = va_arg( al, int* ); argno++;
		bufptr = va_arg( al, void* ); argno++;
		*arglen = ((resp[index++] & ~L1_ARG_UNKNOWN) & 0xff);
		BCOPY( &(resp[index]), bufptr, *arglen  );
		index += (*arglen);
	    }
	    
	    else {
		/* unhandled type */
		va_end( al );
		DUMP_RESP;
		return -1;
	    }
        }
    }
    va_end( al );
  
    if( (l1_fldno != 0) || (argno != resp_nargs) ) {
        /* wrong number of arguments */
	DUMP_RESP;
        return -1;
    }
    return 0;
}




/* sc_send takes as arguments a system controller struct, a
 * buffer which contains a Bedrock<->L1 "request" message,
 * the message length, and the subchannel (presumably obtained
 * from an earlier invocation of sc_open) over which the
 * message is to be sent.  The final argument ("wait") indicates
 * whether the send is to be performed synchronously or not.
 *
 * sc_send returns either zero or an error value.  Synchronous sends 
 * (wait != 0) will not return until the data has actually been sent
 * to the UART.  Synchronous sends generally receive privileged
 * treatment.  The intent is that they be used sparingly, for such
 * purposes as kernel printf's (the "ducons" routines).  Run-of-the-mill
 * console output and L1 requests should NOT use a non-zero value
 * for wait.
 */
int
sc_send( l1sc_t *sc, int ch, char *msg, int len, int wait )
{
    char type_and_subch;
    int result;

    if( (ch < 0) || ( ch >= BRL1_NUM_SUBCHANS) ) {
        return SC_BADSUBCH;
    }

    /* Verify that this is an open subchannel
     */
    if( sc->subch[ch].use == BRL1_SUBCH_FREE )
    {
        return SC_NOPEN;
    }
       
    type_and_subch = (BRL1_REQUEST | ((u_char)ch));
    result = brl1_send( sc, msg, len, type_and_subch, wait );

    /* If we sent as much as we asked to, return "ok". */
    if( result == len )
	return( SC_SUCCESS );

    /* Or, if we sent less, than either the UART is busy or
     * we're trying to send too large a packet anyway.
     */
    else if( result >= 0 && result < len )
	return( SC_BUSY );

    /* Or, if something else went wrong (result < 0), then
     * return that error value.
     */
    else
	return( result );
}



/* subch_pull_msg pulls a message off the receive queue for subch
 * and places it the buffer pointed to by msg.  This routine should only
 * be called when the caller already knows a message is available on the
 * receive queue (and, in the kernel, only when the subchannel data lock
 * is held by the caller).
 */
static void
subch_pull_msg( brl1_sch_t *subch, char *msg, int *len )
{
    sc_cq_t *q;         /* receive queue */
    int before_wrap,    /* packet may be split into two different       */
        after_wrap;     /*   pieces to acommodate queue wraparound      */

    /* pull message off the receive queue */
    q = subch->iqp;

    cq_rem( q, *len );   /* remove length byte and store */
    cq_discard( q );     /* remove type/subch byte and discard */

    if ( *len > 0 )
	(*len)--;        /* don't count type/subch byte in length returned */

    if( (q->opos + (*len)) > BRL1_QSIZE ) {
        before_wrap = BRL1_QSIZE - q->opos;
        after_wrap = (*len) - before_wrap;
    }
    else {
        before_wrap = (*len);
        after_wrap = 0;
    }

    BCOPY( q->buf + q->opos, msg, before_wrap  );
    if( after_wrap ) {
        BCOPY( q->buf, msg + before_wrap, after_wrap  );
	q->opos = after_wrap;
    }
    else {
	q->opos = ((q->opos + before_wrap) & (BRL1_QSIZE - 1));
    }
    atomic_dec(&(subch->packet_arrived));
}


/* sc_recv_poll can be called as a blocking or non-blocking function;
 * it attempts to pull a message off of the subchannel specified
 * in the argument list (ch).
 *
 * The "block" argument, if non-zero, is interpreted as a timeout
 * delay (to avoid permanent waiting).
 */

int
sc_recv_poll( l1sc_t *sc, int ch, char *msg, int *len, uint64_t block )
{
    int is_msg = 0;
    brl1_sch_t *subch = &(sc->subch[ch]);

    rtc_time_t exp_time = rtc_time() + block;

    /* sanity check-- make sure this is an open subchannel */
    if( subch->use == BRL1_SUBCH_FREE )
	return( SC_NOPEN );

    do {

        /* kick the next lower layer and see if it pulls anything in
         */
	brl1_receive( sc );
	is_msg = atomic_read(&subch->packet_arrived);

    } while( block && !is_msg && (rtc_time() < exp_time) );

    if( !is_msg ) {
	/* no message and we didn't care to wait for one */
	return( SC_NMSG );
    }

    SUBCH_DATA_LOCK( subch );
    subch_pull_msg( subch, msg, len );
    SUBCH_DATA_UNLOCK( subch );

    return( SC_SUCCESS );
}
    

/* Like sc_recv_poll, sc_recv_intr can be called in either a blocking
 * or non-blocking mode.  Rather than polling until an appointed timeout,
 * however, sc_recv_intr sleeps on a syncrhonization variable until a
 * signal from the lower layer tells us that a packet has arrived.
 *
 * sc_recv_intr can't be used with remote (router) L1s.
 */
int
sc_recv_intr( l1sc_t *sc, int ch, char *msg, int *len, uint64_t block )
{
    int is_msg = 0;
    brl1_sch_t *subch = &(sc->subch[ch]);

    do {
	SUBCH_DATA_LOCK(subch);
	is_msg = atomic_read(&subch->packet_arrived);
	if( !is_msg && block ) {
	    /* wake me when you've got something */
	    subch->rx_notify = sc_data_ready;
	    sv_wait( &(subch->arrive_sv), 0, 0);
	    if( subch->use == BRL1_SUBCH_FREE ) {
		/* oops-- somebody closed our subchannel while we were
		 * sleeping!
		 */

		/* no need to unlock since the channel's closed anyhow */
		return( SC_NOPEN );
	    }
	}
    } while( !is_msg && block );

    if( !is_msg ) {
	/* no message and we didn't care to wait for one */
	SUBCH_DATA_UNLOCK( subch );
	return( SC_NMSG );
    }

    subch_pull_msg( subch, msg, len );
    SUBCH_DATA_UNLOCK( subch );

    return( SC_SUCCESS );
}

/* sc_command implements a (blocking) combination of sc_send and sc_recv.
 * It is intended to be the SN1 equivalent of SN0's "elsc_command", which
 * issued a system controller command and then waited for a response from
 * the system controller before returning.
 *
 * cmd points to the outgoing command; resp points to the buffer in
 * which the response is to be stored.  Both buffers are assumed to
 * be the same length; if there is any doubt as to whether the
 * response buffer is long enough to hold the L1's response, then
 * make it BRL1_QSIZE bytes-- no Bedrock<->L1 message can be any
 * bigger.
 *
 * Be careful using the same buffer for both cmd and resp; it could get
 * hairy if there were ever an L1 command reqeuest that spanned multiple
 * packets.  (On the other hand, that would require some additional
 * rewriting of the L1 command interface anyway.)
 */
#define __RETRIES	50
#define __WAIT_SEND	( sc->uart != BRL1_LOCALUART )
#define __WAIT_RECV	10000000


int
sc_command( l1sc_t *sc, int ch, char *cmd, char *resp, int *len )
{
#ifndef CONFIG_SERIAL_SGI_L1_PROTOCOL
    return SC_NMSG;
#else
    int result;
    int retries;

    if ( IS_RUNNING_ON_SIMULATOR() )
    	return SC_NMSG;

    retries = __RETRIES;

    while( (result = sc_send( sc, ch, cmd, *len, __WAIT_SEND )) < 0 ) {
	if( result == SC_BUSY ) {
	    retries--;
	    if( retries <= 0 )
		return result;
	    uart_delay(500);
	}
	else {
	    return result;
	}
    }
    
    /* block on sc_recv_* */
#ifdef LATER
    if( sc->uart == BRL1_LOCALUART ) {
	return( sc_recv_intr( sc, ch, resp, len, __WAIT_RECV ) );
    }
    else
#endif	/* LATER */
    {
	return( sc_recv_poll( sc, ch, resp, len, __WAIT_RECV ) );
    }
#endif /* CONFIG_SERIAL_SGI_L1_PROTOCOL */
}

/* sc_command_kern is a knuckle-dragging, no-patience version of sc_command
 * used in situations where the kernel has a command that shouldn't be
 * delayed until the send buffer clears.  sc_command should be used instead
 * under most circumstances.
 */
int
sc_command_kern( l1sc_t *sc, int ch, char *cmd, char *resp, int *len )
{
#ifndef CONFIG_SERIAL_SGI_L1_PROTOCOL
    return SC_NMSG;
#else
    int result;

    if ( IS_RUNNING_ON_SIMULATOR() )
    	return SC_NMSG;

    if( (result = sc_send( sc, ch, cmd, *len, 1 )) < 0 ) {
	return result;
    }

    return( sc_recv_poll( sc, ch, resp, len, __WAIT_RECV ) );
#endif /* CONFIG_SERIAL_SGI_L1_PROTOCOL */
}



/* sc_poll checks the queue corresponding to the given
 * subchannel to see if there's anything available.  If
 * not, it kicks the brl1 layer and then checks again.
 *
 * Returns 1 if input is available on the given queue,
 * 0 otherwise.
 */
int
sc_poll( l1sc_t *sc, int ch )
{
    brl1_sch_t *subch = &(sc->subch[ch]);

    if( atomic_read(&subch->packet_arrived) )
	return 1;

    brl1_receive( sc );

    if( atomic_read(&subch->packet_arrived) )
	return 1;

    return 0;
}

/* for now, sc_init just calls brl1_init
 */
void
sc_init( l1sc_t *sc, nasid_t nasid, net_vec_t uart )
{
    if ( !IS_RUNNING_ON_SIMULATOR() )
    	brl1_init( sc, nasid, uart );
}

/* sc_dispatch_env_event handles events sent from the system control
 * network's environmental monitor tasks.
 */

#ifdef LINUX_KERNEL_THREADS

static void
sc_dispatch_env_event( uint code, int argc, char *args, int maxlen )
{
    int j, i = 0;
    uint32_t ESPcode;

    switch( code ) {
	/* for now, all codes do the same thing: grab two arguments
	 * and print a cmn_err_tag message */
      default:
	/* check number of arguments */
	if( argc != 2 ) {
	    L1_DBG_PRF(( "sc_dispatch_env_event: "
			 "expected 2 arguments, got %d\n", argc ));
	    return;
	}
	
	/* get ESP code (integer argument) */
	if( args[i++] != L1_ARG_INT ) {
	    L1_DBG_PRF(( "sc_dispatch_env_event: "
			 "expected integer argument\n" ));
	    return;
	}
	/* WARNING: highly endian */
	COPY_BUFFER_TO_INT(args, i, ESPcode);

	/* verify string argument */
	if( args[i++] != L1_ARG_ASCII ) {
	    L1_DBG_PRF(( "sc_dispatch_env_event: "
			 "expected an ASCII string\n" ));
	    return;
	}
	for( j = i; j < maxlen; j++ ) {
	    if( args[j] == '\0' ) break; /* found string termination */
	}
	if( j == maxlen ) {
	    j--;
	    L1_DBG_PRF(( "sc_dispatch_env_event: "
			 "message too long-- truncating\n" ));
	}

	/* strip out trailing cr/lf */
	for( ; 
	     j > 1 && ((args[j-1] == 0xd) || (args[j-1] == 0xa)); 
	     j-- );
	args[j] = '\0';
	
	/* strip out leading cr/lf */
	for( ;
	     i < j && ((args[i] == 0xd) || (args[i] == 0xa));
	     i++ );
    }
}
#endif	/* LINUX_KERNEL_THREADS */


/* sc_event waits for events to arrive from the system controller, and
 * prints appropriate messages to the syslog.
 */

#ifdef LINUX_KERNEL_THREADS
static void
sc_event( l1sc_t *sc, int ch )
{
    char event[BRL1_QSIZE];
    int i;
    int result;
    int event_len;
    uint32_t ev_src;
    uint32_t ev_code;
    int ev_argc;

    while(1) {
	
	bzero( event, BRL1_QSIZE );

	/*
	 * wait for an event 
	 */
	result = sc_recv_intr( sc, ch, event, &event_len, 1 );
	if( result != SC_SUCCESS ) {
	    PRINT_WARNING("Error receiving sysctl event on nasid %d\n",
		     sc->nasid );
	}
	else {
	    /*
	     * an event arrived; break it down into useful pieces
	     */
#if defined(L1_DEBUG) && 0
	    int ix;
	    printf( "Event packet received:\n" );
	    for (ix = 0; ix < 64; ix++) {
		printf( "%x%x ", ((event[ix] >> 4) & ((uint64_t)0xf)),
			(event[ix] & ((uint64_t)0xf)) );
		if( (ix % 16) == 0xf ) printf( "\n" );
	    }
#endif /* L1_DEBUG */

	    i = 0;

	    /* get event source */
	    COPY_BUFFER_TO_INT(event, i, ev_src);
	    COPY_BUFFER_TO_INT(event, i, ev_code);

	    /* get arg count */
	    ev_argc = (event[i++] & 0xffUL);
	    
	    /* dispatch events by task */
	    switch( (ev_src & L1_ADDR_TASK_MASK) >> L1_ADDR_TASK_SHFT )
	    {
	      case L1_ADDR_TASK_ENV: /* environmental monitor event */
		sc_dispatch_env_event( ev_code, ev_argc, &(event[i]), 
				       BRL1_QSIZE - i );
		break;

	      default: /* unhandled task type */
		L1_DBG_PRF(( "Unhandled event type received from system "
			     "controllers: source task %x\n",
			     (ev_src & L1_ADDR_TASK_MASK) >> L1_ADDR_TASK_SHFT
			   ));
	    }
	}
	
    }			
}
#endif	/* LINUX_KERNEL_THREADS */

/* sc_listen sets up a service thread to listen for incoming events.
 */
void
sc_listen( l1sc_t *sc )
{
    int result;
    brl1_sch_t *subch;

    char        msg[BRL1_QSIZE];
    int         len;    /* length of message being sent */