static void poll_rx()

in zatm.c [361:481]

• 117 lines of code
• 21 McCabe index (conditional complexity)

static void poll_rx(struct atm_dev *dev,int mbx)
{
	struct zatm_dev *zatm_dev;
	unsigned long pos;
	u32 x;
	int error;

	EVENT("poll_rx\n",0,0);
	zatm_dev = ZATM_DEV(dev);
	pos = (zatm_dev->mbx_start[mbx] & ~0xffffUL) | zin(MTA(mbx));
	while (x = zin(MWA(mbx)), (pos & 0xffff) != x) {
		u32 *here;
		struct sk_buff *skb;
		struct atm_vcc *vcc;
		int cells,size,chan;

		EVENT("MBX: host 0x%lx, nic 0x%x\n",pos,x);
		here = (u32 *) pos;
		if (((pos += 16) & 0xffff) == zatm_dev->mbx_end[mbx])
			pos = zatm_dev->mbx_start[mbx];
		cells = here[0] & uPD98401_AAL5_SIZE;
#if 0
printk("RX IND: 0x%x, 0x%x, 0x%x, 0x%x\n",here[0],here[1],here[2],here[3]);
{
unsigned long *x;
		printk("POOL: 0x%08x, 0x%08x\n",zpeekl(zatm_dev,
		      zatm_dev->pool_base),
		      zpeekl(zatm_dev,zatm_dev->pool_base+1));
		x = (unsigned long *) here[2];
		printk("[0..3] = 0x%08lx, 0x%08lx, 0x%08lx, 0x%08lx\n",
		    x[0],x[1],x[2],x[3]);
}
#endif
		error = 0;
		if (here[3] & uPD98401_AAL5_ERR) {
			error = (here[3] & uPD98401_AAL5_ES) >>
			    uPD98401_AAL5_ES_SHIFT;
			if (error == uPD98401_AAL5_ES_DEACT ||
			    error == uPD98401_AAL5_ES_FREE) continue;
		}
EVENT("error code 0x%x/0x%x\n",(here[3] & uPD98401_AAL5_ES) >>
  uPD98401_AAL5_ES_SHIFT,error);
		skb = ((struct rx_buffer_head *) bus_to_virt(here[2]))->skb;
		__net_timestamp(skb);
#if 0
printk("[-3..0] 0x%08lx 0x%08lx 0x%08lx 0x%08lx\n",((unsigned *) skb->data)[-3],
  ((unsigned *) skb->data)[-2],((unsigned *) skb->data)[-1],
  ((unsigned *) skb->data)[0]);
#endif
		EVENT("skb 0x%lx, here 0x%lx\n",(unsigned long) skb,
		    (unsigned long) here);
#if 0
printk("dummy: 0x%08lx, 0x%08lx\n",dummy[0],dummy[1]);
#endif
		size = error ? 0 : ntohs(((__be16 *) skb->data)[cells*
		    ATM_CELL_PAYLOAD/sizeof(u16)-3]);
		EVENT("got skb 0x%lx, size %d\n",(unsigned long) skb,size);
		chan = (here[3] & uPD98401_AAL5_CHAN) >>
		    uPD98401_AAL5_CHAN_SHIFT;
		if (chan < zatm_dev->chans && zatm_dev->rx_map[chan]) {
			int pos;
			vcc = zatm_dev->rx_map[chan];
			pos = ZATM_VCC(vcc)->pool;
			if (skb == zatm_dev->last_free[pos])
				zatm_dev->last_free[pos] = NULL;
			skb_unlink(skb, zatm_dev->pool + pos);
		}
		else {
			printk(KERN_ERR DEV_LABEL "(itf %d): RX indication "
			    "for non-existing channel\n",dev->number);
			size = 0;
			vcc = NULL;
			event_dump();
		}
		if (error) {
			static unsigned long silence = 0;
			static int last_error = 0;

			if (error != last_error ||
			    time_after(jiffies, silence)  || silence == 0){
				printk(KERN_WARNING DEV_LABEL "(itf %d): "
				    "chan %d error %s\n",dev->number,chan,
				    err_txt[error]);
				last_error = error;
				silence = (jiffies+2*HZ)|1;
			}
			size = 0;
		}
		if (size && (size > cells*ATM_CELL_PAYLOAD-ATM_AAL5_TRAILER ||
		    size <= (cells-1)*ATM_CELL_PAYLOAD-ATM_AAL5_TRAILER)) {
			printk(KERN_ERR DEV_LABEL "(itf %d): size %d with %d "
			    "cells\n",dev->number,size,cells);
			size = 0;
			event_dump();
		}
		if (size > ATM_MAX_AAL5_PDU) {
			printk(KERN_ERR DEV_LABEL "(itf %d): size too big "
			    "(%d)\n",dev->number,size);
			size = 0;
			event_dump();
		}
		if (!size) {
			dev_kfree_skb_irq(skb);
			if (vcc) atomic_inc(&vcc->stats->rx_err);
			continue;
		}
		if (!atm_charge(vcc,skb->truesize)) {
			dev_kfree_skb_irq(skb);
			continue;
		}
		skb->len = size;
		ATM_SKB(skb)->vcc = vcc;
		vcc->push(vcc,skb);
		atomic_inc(&vcc->stats->rx);
	}
	zout(pos & 0xffff,MTA(mbx));
#if 0 /* probably a stupid idea */
	refill_pool(dev,zatm_vcc->pool);
		/* maybe this saves us a few interrupts */
#endif
}