smc9194.c

powerpc内核mpc8241linux系统下net驱动程序

#ifndef SUPPORT_OLD_KERNEL
/*
 . Function: smc_setmulticast( int ioaddr, int count, dev_mc_list * adds )
 . Purpose:
 .    This sets the internal hardware table to filter out unwanted multicast
 .    packets before they take up memory.
 .
 .    The SMC chip uses a hash table where the high 6 bits of the CRC of
 .    address are the offset into the table.  If that bit is 1, then the
 .    multicast packet is accepted.  Otherwise, it's dropped silently.
 .
 .    To use the 6 bits as an offset into the table, the high 3 bits are the
 .    number of the 8 bit register, while the low 3 bits are the bit within
 .    that register.
 .
 . This routine is based very heavily on the one provided by Peter Cammaert.
*/


static void smc_setmulticast( int ioaddr, int count, struct dev_mc_list * addrs ) {
	int			i;
	unsigned char		multicast_table[ 8 ];
	struct dev_mc_list	* cur_addr;
	/* table for flipping the order of 3 bits */
	unsigned char invert3[] = { 0, 4, 2, 6, 1, 5, 3, 7 };

	/* start with a table of all zeros: reject all */
	memset( multicast_table, 0, sizeof( multicast_table ) );

	cur_addr = addrs;
	for ( i = 0; i < count ; i ++, cur_addr = cur_addr->next  ) {
		int position;

		/* do we have a pointer here? */
		if ( !cur_addr )
			break;
		/* make sure this is a multicast address - shouldn't this
		   be a given if we have it here ? */
		if ( !( *cur_addr->dmi_addr & 1 ) )
			continue;

		/* only use the low order bits */
		position = crc32( cur_addr->dmi_addr, 6 ) & 0x3f;

		/* do some messy swapping to put the bit in the right spot */
		multicast_table[invert3[position&7]] |=
					(1<<invert3[(position>>3)&7]);

	}
	/* now, the table can be loaded into the chipset */
	SMC_SELECT_BANK( 3 );

	for ( i = 0; i < 8 ; i++ ) {
		outb( multicast_table[i], ioaddr + MULTICAST1 + i );
	}
}

/*
  Finds the CRC32 of a set of bytes.
  Again, from Peter Cammaert's code.
*/
static int crc32( char * s, int length ) {
	/* indices */
	int perByte;
	int perBit;
	/* crc polynomial for Ethernet */
	const unsigned long poly = 0xedb88320;
	/* crc value - preinitialized to all 1's */
	unsigned long crc_value = 0xffffffff;

	for ( perByte = 0; perByte < length; perByte ++ ) {
		unsigned char	c;

		c = *(s++);
		for ( perBit = 0; perBit < 8; perBit++ ) {
			crc_value = (crc_value>>1)^
				(((crc_value^c)&0x01)?poly:0);
			c >>= 1;
		}
	}
	return	crc_value;
}

#endif


/*
 . Function: smc_wait_to_send_packet( struct sk_buff * skb, struct device * )
 . Purpose:
 .    Attempt to allocate memory for a packet, if chip-memory is not
 .    available, then tell the card to generate an interrupt when it
 .    is available.
 .
 . Algorithm:
 .
 . o	if the saved_skb is not currently null, then drop this packet
 .	on the floor.  This should never happen, because of TBUSY.
 . o	if the saved_skb is null, then replace it with the current packet,
 . o	See if I can sending it now.
 . o 	(NO): Enable interrupts and let the interrupt handler deal with it.
 . o	(YES):Send it now.
*/
static int smc_wait_to_send_packet( struct sk_buff * skb, struct device * dev )
{
	struct smc_local *lp 	= (struct smc_local *)dev->priv;
	unsigned short ioaddr 	= dev->base_addr;
	word 			length;
	unsigned short 		numPages;
	word			time_out;

	if ( lp->saved_skb) {
		/* THIS SHOULD NEVER HAPPEN. */
		lp->stats.tx_aborted_errors++;
		printk(CARDNAME": Bad Craziness - sent packet while busy.\n" );
		return 1;
	}
	lp->saved_skb = skb;

	length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;

	/*
	. the MMU wants the number of pages to be the number of 256 bytes
    	. 'pages', minus 1 ( since a packet can't ever have 0 pages :) )
	*/
	numPages = length / 256;

	if (numPages > 7 ) {
		printk(CARDNAME": Far too big packet error. \n");
		/* freeing the packet is a good thing here... but should
		 . any packets of this size get down here?   */
		dev_kfree_skb (skb);
		lp->saved_skb = NULL;
		/* this IS an error, but, i don't want the skb saved */
		return 0;
	}
	/* either way, a packet is waiting now */
	lp->packets_waiting++;

	/* now, try to allocate the memory */
	SMC_SELECT_BANK( 2 );
	outw( MC_ALLOC | numPages, ioaddr + MMU_CMD );
	/*
 	. Performance Hack
	.
 	. wait a short amount of time.. if I can send a packet now, I send
	. it now.  Otherwise, I enable an interrupt and wait for one to be
	. available.
	.
	. I could have handled this a slightly different way, by checking to
	. see if any memory was available in the FREE MEMORY register.  However,
	. either way, I need to generate an allocation, and the allocation works
	. no matter what, so I saw no point in checking free memory.
	*/
	time_out = MEMORY_WAIT_TIME;
	do {
		word	status;

		status = inb( ioaddr + INTERRUPT );
		if ( status & IM_ALLOC_INT ) {
			/* acknowledge the interrupt */
			outb( IM_ALLOC_INT, ioaddr + INTERRUPT );
  			break;
		}
   	} while ( -- time_out );

   	if ( !time_out ) {
		/* oh well, wait until the chip finds memory later */
		SMC_ENABLE_INT( IM_ALLOC_INT );
      		PRINTK2((CARDNAME": memory allocation deferred. \n"));
		/* it's deferred, but I'll handle it later */
      		return 0;
   	}
	/* or YES! I can send the packet now.. */
	smc_hardware_send_packet(dev);

	return 0;
}

/*
 . Function:  smc_hardware_send_packet(struct device * )
 . Purpose:
 .	This sends the actual packet to the SMC9xxx chip.
 .
 . Algorithm:
 . 	First, see if a saved_skb is available.
 .		( this should NOT be called if there is no 'saved_skb'
 .	Now, find the packet number that the chip allocated
 .	Point the data pointers at it in memory
 .	Set the length word in the chip's memory
 .	Dump the packet to chip memory
 .	Check if a last byte is needed ( odd length packet )
 .		if so, set the control flag right
 . 	Tell the card to send it
 .	Enable the transmit interrupt, so I know if it failed
 . 	Free the kernel data if I actually sent it.
*/
static void smc_hardware_send_packet( struct device * dev )
{
	struct smc_local *lp = (struct smc_local *)dev->priv;
	byte	 		packet_no;
	struct sk_buff * 	skb = lp->saved_skb;
	word			length;
	unsigned short		ioaddr;
	byte			* buf;

	ioaddr = dev->base_addr;

	if ( !skb ) {
		PRINTK((CARDNAME": In XMIT with no packet to send \n"));
		return;
	}
	length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	buf = skb->data;

	/* If I get here, I _know_ there is a packet slot waiting for me */
	packet_no = inb( ioaddr + PNR_ARR + 1 );
	if ( packet_no & 0x80 ) {
		/* or isn't there?  BAD CHIP! */
		printk(KERN_DEBUG CARDNAME": Memory allocation failed. \n");
		kfree(skb);
		lp->saved_skb = NULL;
		dev->tbusy = 0;
		return;
	}

	/* we have a packet address, so tell the card to use it */
	outb( packet_no, ioaddr + PNR_ARR );

	/* point to the beginning of the packet */
	outw( PTR_AUTOINC , ioaddr + POINTER );

   	PRINTK3((CARDNAME": Trying to xmit packet of length %x\n", length ));
#if SMC_DEBUG > 2
	print_packet( buf, length );
#endif

	/* send the packet length ( +6 for status, length and ctl byte )
 	   and the status word ( set to zeros ) */
#ifdef USE_32_BIT
	outl(  (length +6 ) << 16 , ioaddr + DATA_1 );
#else
	outw( 0, ioaddr + DATA_1 );
	/* send the packet length ( +6 for status words, length, and ctl*/
	outb( (length+6) & 0xFF,ioaddr + DATA_1 );
	outb( (length+6) >> 8 , ioaddr + DATA_1 );
#endif

	/* send the actual data
	 . I _think_ it's faster to send the longs first, and then
	 . mop up by sending the last word.  It depends heavily
 	 . on alignment, at least on the 486.  Maybe it would be
 	 . a good idea to check which is optimal?  But that could take
	 . almost as much time as is saved?
	*/
#ifdef USE_32_BIT
	if ( length & 0x2  ) {
		outsl(ioaddr + DATA_1, buf,  length >> 2 );
		outw( *((word *)(buf + (length & 0xFFFFFFFC))),ioaddr +DATA_1);
	}
	else
		outsl(ioaddr + DATA_1, buf,  length >> 2 );
#else
	outsw(ioaddr + DATA_1 , buf, (length ) >> 1);
#endif
	/* Send the last byte, if there is one.   */

	if ( (length & 1) == 0 ) {
		outw( 0, ioaddr + DATA_1 );
	} else {
		outb( buf[length -1 ], ioaddr + DATA_1 );
		outb( 0x20, ioaddr + DATA_1);
	}

	/* enable the interrupts */
	SMC_ENABLE_INT( (IM_TX_INT | IM_TX_EMPTY_INT) );

	/* and let the chipset deal with it */
	outw( MC_ENQUEUE , ioaddr + MMU_CMD );

	PRINTK2((CARDNAME": Sent packet of length %d \n",length));

	lp->saved_skb = NULL;
	dev_kfree_skb (skb);

	dev->trans_start = jiffies;

	/* we can send another packet */
	dev->tbusy = 0;


	return;
}

/*-------------------------------------------------------------------------
 |
 | smc_init( struct device * dev )
 |   Input parameters:
 |	dev->base_addr == 0, try to find all possible locations
 |	dev->base_addr == 1, return failure code
 |	dev->base_addr == 2, always allocate space,  and return success
 |	dev->base_addr == <anything else>   this is the address to check
 |
 |   Output:
 |	0 --> there is a device
 |	anything else, error
 |
 ---------------------------------------------------------------------------
*/
__initfunc(int smc_init(struct device *dev))
{
	int i;
	int base_addr = dev ? dev->base_addr : 0;

	/*  try a specific location */
	if (base_addr > 0x1ff)	{
		int	error;
		error = smc_probe(base_addr);
		if ( 0 == error ) {
			return smc_initcard( dev, base_addr );
		}
		return error;
	} else {
		if ( 0 != base_addr ) {
			return -ENXIO;
		}
	}

	/* check every ethernet address */
	for (i = 0; smc_portlist[i]; i++) {
		int ioaddr = smc_portlist[i];

		/* check if the area is available */
		if (check_region( ioaddr , SMC_IO_EXTENT))
			continue;

		/* check this specific address */
		if ( smc_probe( ioaddr ) == 0)  {
			return smc_initcard( dev, ioaddr  );
		}
	}

	/* couldn't find anything */
	return -ENODEV;
}

#ifndef NO_AUTOPROBE
/*----------------------------------------------------------------------
 . smc_findirq
 .
 . This routine has a simple purpose -- make the SMC chip generate an
 . interrupt, so an auto-detect routine can detect it, and find the IRQ,
 ------------------------------------------------------------------------
*/
__initfunc(int smc_findirq( int ioaddr ))
{
	int	timeout = 20;


	/* I have to do a STI() here, because this is called from
	   a routine that does an CLI during this process, making it
	   rather difficult to get interrupts for auto detection */
	sti();

	autoirq_setup( 0 );

	/*
	 * What I try to do here is trigger an ALLOC_INT. This is done
	 * by allocating a small chunk of memory, which will give an interrupt
	 * when done.
	 */


	SMC_SELECT_BANK(2);
	/* enable ALLOCation interrupts ONLY */
	outb( IM_ALLOC_INT, ioaddr + INT_MASK );

	/*
 	 . Allocate 512 bytes of memory.  Note that the chip was just
	 . reset so all the memory is available
	*/
	outw( MC_ALLOC | 1, ioaddr + MMU_CMD );

	/*
	 . Wait until positive that the interrupt has been generated
	*/
	while ( timeout ) {
		byte	int_status;

		int_status = inb( ioaddr + INTERRUPT );

		if ( int_status & IM_ALLOC_INT )
			break;		/* got the interrupt */
		timeout--;
	}
	/* there is really nothing that I can do here if timeout fails,
	   as autoirq_report will return a 0 anyway, which is what I
	   want in this case.   Plus, the clean up is needed in both
	   cases.  */

	/* DELAY HERE!
	   On a fast machine, the status might change before the interrupt
	   is given to the processor.  This means that the interrupt was
	   never detected, and autoirq_report fails to report anything.
	   This should fix autoirq_* problems.
	*/
	SMC_DELAY();
	SMC_DELAY();

	/* and disable all interrupts again */
	outb( 0, ioaddr + INT_MASK );

	/* clear hardware interrupts again, because that's how it
	   was when I was called... */
	cli();

	/* and return what I found */
	return autoirq_report( 0 );
}
#endif

/*----------------------------------------------------------------------
 . Function: smc_probe( int ioaddr )
 .
 . Purpose:
 .	Tests to see if a given ioaddr points to an SMC9xxx chip.
 .	Returns a 0 on success
 .
 . Algorithm:
 .	(1) see if the high byte of BANK_SELECT is 0x33
 . 	(2) compare the ioaddr with the base register's address
 .	(3) see if I recognize the chip ID in the appropriate register
 .
 .---------------------------------------------------------------------
 */

__initfunc(static int smc_probe( int ioaddr ))
{
	unsigned int	bank;
	word	revision_register;
	word  base_address_register;

	/* First, see if the high byte is 0x33 */
	bank = inw( ioaddr + BANK_SELECT );
	if ( (bank & 0xFF00) != 0x3300 ) {