sdla_chdlc.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

#endif

	/* Get Multicast Information */
	chdlc_priv_area->mc = conf->mc;

	/* prepare network device data space for registration */
#ifdef LINUX_2_4
	strcpy(dev->name,card->u.c.if_name);
#else
	dev->name = (char *)kmalloc(strlen(card->u.c.if_name) + 2, GFP_KERNEL); 
	sprintf(dev->name, "%s", card->u.c.if_name);
#endif

	dev->init = &if_init;
	dev->priv = chdlc_priv_area;

	/* Initialize the polling task routine */
#ifndef LINUX_2_4
	chdlc_priv_area->poll_task.next = NULL;
#endif
	chdlc_priv_area->poll_task.sync=0;
	chdlc_priv_area->poll_task.routine = (void*)(void*)chdlc_poll;
	chdlc_priv_area->poll_task.data = dev;

	/* Initialize the polling delay timer */
	init_timer(&chdlc_priv_area->poll_delay_timer);
	chdlc_priv_area->poll_delay_timer.data = (unsigned long)dev;
	chdlc_priv_area->poll_delay_timer.function = chdlc_poll_delay;
	
	printk(KERN_INFO "\n");

	return 0;
}


/****** Network Device Interface ********************************************/

/*============================================================================
 * Initialize Linux network interface.
 *
 * This routine is called only once for each interface, during Linux network
 * interface registration.  Returning anything but zero will fail interface
 * registration.
 */
static int if_init (netdevice_t* dev)
	{
	chdlc_private_area_t* chdlc_priv_area = dev->priv;
	sdla_t* card = chdlc_priv_area->card;
	wan_device_t* wandev = &card->wandev;
#ifdef LINUX_2_0
	int i;
#endif

	/* Initialize device driver entry points */
	dev->open		= &if_open;
	dev->stop		= &if_close;
	dev->hard_header	= &if_header;
	dev->rebuild_header	= &if_rebuild_hdr;
	dev->hard_start_xmit	= &if_send;
	dev->get_stats		= &if_stats;
#ifdef LINUX_2_4
	dev->tx_timeout		= &if_tx_timeout;
	dev->watchdog_timeo	= TX_TIMEOUT;
#endif

	
	/* Initialize media-specific parameters */
	dev->flags		|= IFF_POINTOPOINT;
	dev->flags		|= IFF_NOARP;

	/* Enable Mulitcasting if user selected */
	if (chdlc_priv_area->mc == WANOPT_YES){
		dev->flags 	|= IFF_MULTICAST;
	}
	
#ifdef LINUX_2_0
	dev->family		= AF_INET;
#endif	

	if (chdlc_priv_area->true_if_encoding){
#if defined(LINUX_2_1) || defined(LINUX_2_4)
		dev->type	= ARPHRD_HDLC; /* This breaks the tcpdump */
#else
		dev->type	= ARPHRD_PPP;
#endif
	}else{
		dev->type	= ARPHRD_PPP;
	}
	
	dev->mtu		= card->wandev.mtu;
	/* for API usage, add the API header size to the requested MTU size */
	if(card->u.c.usedby == API) {
		dev->mtu += sizeof(api_tx_hdr_t);
	}
 
	dev->hard_header_len	= CHDLC_HDR_LEN;

	/* Initialize hardware parameters */
	dev->irq	= wandev->irq;
	dev->dma	= wandev->dma;
	dev->base_addr	= wandev->ioport;
	dev->mem_start	= wandev->maddr;
	dev->mem_end	= wandev->maddr + wandev->msize - 1;

	/* Set transmit buffer queue length 
	 * If too low packets will not be retransmitted 
         * by stack.
	 */
        dev->tx_queue_len = 100;
   
	/* Initialize socket buffers */
#if !defined(LINUX_2_1) && !defined(LINUX_2_4)
        for (i = 0; i < DEV_NUMBUFFS; ++i)
                skb_queue_head_init(&dev->buffs[i]);
#endif
	return 0;
}

/*============================================================================
 * Open network interface.
 * o enable communications and interrupts.
 * o prevent module from unloading by incrementing use count
 *
 * Return 0 if O.k. or errno.
 */
static int if_open (netdevice_t* dev)
{
	chdlc_private_area_t* chdlc_priv_area = dev->priv;
	sdla_t* card = chdlc_priv_area->card;
	struct timeval tv;
	int err = 0;

	/* Only one open per interface is allowed */

	if (is_dev_running(dev))
		return -EBUSY;

#if defined(LINUX_2_1) || defined(LINUX_2_4)
	/* Initialize the task queue */
	chdlc_priv_area->tq_working=0;

#ifndef LINUX_2_4
	chdlc_priv_area->common.wanpipe_task.next = NULL;
#endif
	chdlc_priv_area->common.wanpipe_task.sync = 0;
	chdlc_priv_area->common.wanpipe_task.routine = (void *)(void *)chdlc_bh;
	chdlc_priv_area->common.wanpipe_task.data = dev;

	/* Allocate and initialize BH circular buffer */
	/* Add 1 to MAX_BH_BUFF so we don't have test with (MAX_BH_BUFF-1) */
	chdlc_priv_area->bh_head = kmalloc((sizeof(bh_data_t)*(MAX_BH_BUFF+1)),GFP_ATOMIC);
	memset(chdlc_priv_area->bh_head,0,(sizeof(bh_data_t)*(MAX_BH_BUFF+1)));
	atomic_set(&chdlc_priv_area->bh_buff_used, 0);
#endif
 
	do_gettimeofday(&tv);
	chdlc_priv_area->router_start_time = tv.tv_sec;

#ifdef LINUX_2_4
	netif_start_queue(dev);
#else
	dev->interrupt = 0;
	dev->tbusy = 0;
	dev->start = 1;
#endif

	wanpipe_open(card);

	/* TTY is configured during wanpipe_set_termios
	 * call, not here */
	if (card->tty_opt)
		return err;
	
	set_bit(0,&chdlc_priv_area->config_chdlc);
	chdlc_priv_area->config_chdlc_timeout=jiffies;
	del_timer(&chdlc_priv_area->poll_delay_timer);

	/* Start the CHDLC configuration after 1sec delay.
	 * This will give the interface initilization time
	 * to finish its configuration */
	chdlc_priv_area->poll_delay_timer.expires=jiffies+HZ;
	add_timer(&chdlc_priv_area->poll_delay_timer);
	return err;
}

/*============================================================================
 * Close network interface.
 * o if this is the last close, then disable communications and interrupts.
 * o reset flags.
 */
static int if_close (netdevice_t* dev)
{
	chdlc_private_area_t* chdlc_priv_area = dev->priv;
	sdla_t* card = chdlc_priv_area->card;

#if defined(LINUX_2_1) || defined(LINUX_2_4)

	if (chdlc_priv_area->bh_head){
		int i;
		struct sk_buff *skb;
	
		for (i=0; i<(MAX_BH_BUFF+1); i++){
			skb = ((bh_data_t *)&chdlc_priv_area->bh_head[i])->skb;
			if (skb != NULL){
                		wan_dev_kfree_skb(skb, FREE_READ);
			}
		}
		kfree(chdlc_priv_area->bh_head);
		chdlc_priv_area->bh_head=NULL;
	}
#endif

	stop_net_queue(dev);
#ifndef LINUX_2_4
	dev->start=0;
#endif
	wanpipe_close(card);
	del_timer(&chdlc_priv_area->poll_delay_timer);
	return 0;
}

static void disable_comm (sdla_t *card)
{
	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
	
	if (card->u.c.comm_enabled){
		chdlc_disable_comm_shutdown (card);
	}else{
		flags->interrupt_info_struct.interrupt_permission = 0;	
	}

#if defined(LINUX_2_4) || defined(LINUX_2_1)	
	if (!tty_init_cnt)
		return;

	if (card->tty_opt){
		struct serial_state * state;
		if (!(--tty_init_cnt)){
			int e1,e2;
			*serial_driver.refcount=0;
			
			if ((e1 = tty_unregister_driver(&serial_driver)))
				printk("SERIAL: failed to unregister serial driver (%d)\n",
				       e1);
			if ((e2 = tty_unregister_driver(&callout_driver)))
				printk("SERIAL: failed to unregister callout driver (%d)\n", 
				       e2);
			printk(KERN_INFO "%s: Unregistering TTY Driver, Major %i\n",
					card->devname,WAN_TTY_MAJOR);
		}
		card->tty=NULL;
		tty_card_map[card->tty_minor]=NULL;
		state = &rs_table[card->tty_minor];
		memset(state,0,sizeof(state));
	}
#endif
	return;
}


/*============================================================================
 * Build media header.
 *
 * The trick here is to put packet type (Ethertype) into 'protocol' field of
 * the socket buffer, so that we don't forget it.  If packet type is not
 * supported, set skb->protocol to 0 and discard packet later.
 *
 * Return:	media header length.
 */
static int if_header (struct sk_buff* skb, netdevice_t* dev,
	unsigned short type, void* daddr, void* saddr, unsigned len)
{
	skb->protocol = htons(type);

	return CHDLC_HDR_LEN;
}


#ifdef LINUX_2_4
/*============================================================================
 * Handle transmit timeout event from netif watchdog
 */
static void if_tx_timeout (netdevice_t *dev)
{
    	chdlc_private_area_t* chan = dev->priv;
	sdla_t *card = chan->card;
	
	/* If our device stays busy for at least 5 seconds then we will
	 * kick start the device by making dev->tbusy = 0.  We expect
	 * that our device never stays busy more than 5 seconds. So this                 
	 * is only used as a last resort.
	 */

	++card->wandev.stats.collisions;

	printk (KERN_INFO "%s: Transmit timed out on %s\n", card->devname,dev->name);
	netif_wake_queue (dev);
}
#endif



/*============================================================================
 * Re-build media header.
 *
 * Return:	1	physical address resolved.
 *		0	physical address not resolved
 */
#if defined(LINUX_2_1) || defined(LINUX_2_4)
static int if_rebuild_hdr (struct sk_buff *skb)
{
	return 1;
}
#else
static int if_rebuild_hdr (void* hdr, netdevice_t* dev, unsigned long raddr,
                           struct sk_buff* skb)
{
        return 1;
}
#endif

/*============================================================================
 * Send a packet on a network interface.
 * o set tbusy flag (marks start of the transmission) to block a timer-based
 *   transmit from overlapping.
 * o check link state. If link is not up, then drop the packet.
 * o execute adapter send command.
 * o free socket buffer
 *
 * Return:	0	complete (socket buffer must be freed)
 *		non-0	packet may be re-transmitted (tbusy must be set)
 *
 * Notes:
 * 1. This routine is called either by the protocol stack or by the "net
 *    bottom half" (with interrupts enabled).
 * 2. Setting tbusy flag will inhibit further transmit requests from the
 *    protocol stack and can be used for flow control with protocol layer.
 */
static int if_send (struct sk_buff* skb, netdevice_t* dev)
{
	chdlc_private_area_t *chdlc_priv_area = dev->priv;
	sdla_t *card = chdlc_priv_area->card;
	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
	INTERRUPT_INFORMATION_STRUCT *chdlc_int = &flags->interrupt_info_struct;
	int udp_type = 0;
	unsigned long smp_flags;
	int err=0;

#ifdef LINUX_2_4
	netif_stop_queue(dev);
#endif
	
	if (skb == NULL){
		/* If we get here, some higher layer thinks we've missed an
		 * tx-done interrupt.
		 */
		printk(KERN_INFO "%s: interface %s got kicked!\n",
			card->devname, dev->name);

		wake_net_dev(dev);
		return 0;
	}

#ifndef LINUX_2_4
	if (dev->tbusy){

		/* If our device stays busy for at least 5 seconds then we will
		 * kick start the device by making dev->tbusy = 0.  We expect 
		 * that our device never stays busy more than 5 seconds. So this
		 * is only used as a last resort. 
		 */
                ++card->wandev.stats.collisions;
		if((jiffies - chdlc_priv_area->tick_counter) < (5 * HZ)) {
			return 1;
		}

		printk (KERN_INFO "%s: Transmit timeout !\n",
			card->devname);

		/* unbusy the interface */
		clear_bit(0,&dev->tbusy);
	}
#endif

   	if (ntohs(skb->protocol) != htons(PVC_PROT)){

		/* check the udp packet type */
		
		udp_type = udp_pkt_type(skb, card);

		if (udp_type == UDP_CPIPE_TYPE){
                        if(store_udp_mgmt_pkt(UDP_PKT_FRM_STACK, card, skb, dev,
                                chdlc_priv_area)){
	                	chdlc_int->interrupt_permission |=
					APP_INT_ON_TIMER;
			}
			start_net_queue(dev);
			return 0;
		}

		/* check to see if the source IP address is a broadcast or */
		/* multicast IP address */
                if(chk_bcast_mcast_addr(card, dev, skb)){
			++card->wandev.stats.tx_dropped;
			wan_dev_kfree_skb(skb,FREE_WRITE);
			start_net_queue(dev);
			return 0;
		}
        }

	/* Lock the 508 Card: SMP is supported */
      	if(card->hw.type != SDLA_S514){
		s508_lock(card,&smp_flags);
	} 

    	if(test_and_set_bit(SEND_CRIT, (void*)&card->wandev.critical)) {
	
		printk(KERN_INFO "%s: Critical in if_send: %lx\n",
					card->wandev.name,card->wandev.critical);
                ++card->wandev.stats.tx_dropped;
		start_net_queue(dev);
		goto if_send_exit_crit;
	}

	if(card->u.c.state != WAN_CONNECTED){
       		++card->wandev.stats.tx_dropped;
		start_net_queue(dev);
		
	}else if(!skb->protocol){
        	++card->wandev.stats.tx_errors;
		start_net_queue(dev);
		
	}else {
		void* data = skb->data;
		unsigned len = skb->len;
		unsigned char attr;

		/* If it's an API packet pull off the API
		 * header. Also check that the packet size
		 * is larger than the API header
	         */
		if (card->u.c.usedby == API){
			api_tx_hdr_t* api_tx_hdr;

			/* discard the frame if we are configured for */
			/* 'receive only' mode or if there is no data */
			if (card->u.c.receive_only ||
				(len <= sizeof(api_tx_hdr_t))) {
				
				++card->wandev.stats.tx_dropped;
				start_net_queue(dev);
				goto if_send_exit_crit;
			}
				
			api_tx_hdr = (api_tx_hdr_t *)data;
			attr = api_tx_hdr->attr;
			data += sizeof(api_tx_hdr_t);
			len -= sizeof(api_tx_hdr_t);