static irqreturn_t ns_irq_handler()

in nicstar.c [1060:1230]

• 133 lines of code
• 22 McCabe index (conditional complexity)

static irqreturn_t ns_irq_handler(int irq, void *dev_id)
{
	u32 stat_r;
	ns_dev *card;
	struct atm_dev *dev;
	unsigned long flags;

	card = (ns_dev *) dev_id;
	dev = card->atmdev;
	card->intcnt++;

	PRINTK("nicstar%d: NICStAR generated an interrupt\n", card->index);

	spin_lock_irqsave(&card->int_lock, flags);

	stat_r = readl(card->membase + STAT);

	/* Transmit Status Indicator has been written to T. S. Queue */
	if (stat_r & NS_STAT_TSIF) {
		TXPRINTK("nicstar%d: TSI interrupt\n", card->index);
		process_tsq(card);
		writel(NS_STAT_TSIF, card->membase + STAT);
	}

	/* Incomplete CS-PDU has been transmitted */
	if (stat_r & NS_STAT_TXICP) {
		writel(NS_STAT_TXICP, card->membase + STAT);
		TXPRINTK("nicstar%d: Incomplete CS-PDU transmitted.\n",
			 card->index);
	}

	/* Transmit Status Queue 7/8 full */
	if (stat_r & NS_STAT_TSQF) {
		writel(NS_STAT_TSQF, card->membase + STAT);
		PRINTK("nicstar%d: TSQ full.\n", card->index);
		process_tsq(card);
	}

	/* Timer overflow */
	if (stat_r & NS_STAT_TMROF) {
		writel(NS_STAT_TMROF, card->membase + STAT);
		PRINTK("nicstar%d: Timer overflow.\n", card->index);
	}

	/* PHY device interrupt signal active */
	if (stat_r & NS_STAT_PHYI) {
		writel(NS_STAT_PHYI, card->membase + STAT);
		PRINTK("nicstar%d: PHY interrupt.\n", card->index);
		if (dev->phy && dev->phy->interrupt) {
			dev->phy->interrupt(dev);
		}
	}

	/* Small Buffer Queue is full */
	if (stat_r & NS_STAT_SFBQF) {
		writel(NS_STAT_SFBQF, card->membase + STAT);
		printk("nicstar%d: Small free buffer queue is full.\n",
		       card->index);
	}

	/* Large Buffer Queue is full */
	if (stat_r & NS_STAT_LFBQF) {
		writel(NS_STAT_LFBQF, card->membase + STAT);
		printk("nicstar%d: Large free buffer queue is full.\n",
		       card->index);
	}

	/* Receive Status Queue is full */
	if (stat_r & NS_STAT_RSQF) {
		writel(NS_STAT_RSQF, card->membase + STAT);
		printk("nicstar%d: RSQ full.\n", card->index);
		process_rsq(card);
	}

	/* Complete CS-PDU received */
	if (stat_r & NS_STAT_EOPDU) {
		RXPRINTK("nicstar%d: End of CS-PDU received.\n", card->index);
		process_rsq(card);
		writel(NS_STAT_EOPDU, card->membase + STAT);
	}

	/* Raw cell received */
	if (stat_r & NS_STAT_RAWCF) {
		writel(NS_STAT_RAWCF, card->membase + STAT);
#ifndef RCQ_SUPPORT
		printk("nicstar%d: Raw cell received and no support yet...\n",
		       card->index);
#endif /* RCQ_SUPPORT */
		/* NOTE: the following procedure may keep a raw cell pending until the
		   next interrupt. As this preliminary support is only meant to
		   avoid buffer leakage, this is not an issue. */
		while (readl(card->membase + RAWCT) != card->rawch) {

			if (ns_rcqe_islast(card->rawcell)) {
				struct sk_buff *oldbuf;

				oldbuf = card->rcbuf;
				card->rcbuf = idr_find(&card->idr,
						       ns_rcqe_nextbufhandle(card->rawcell));
				card->rawch = NS_PRV_DMA(card->rcbuf);
				card->rawcell = (struct ns_rcqe *)
						card->rcbuf->data;
				recycle_rx_buf(card, oldbuf);
			} else {
				card->rawch += NS_RCQE_SIZE;
				card->rawcell++;
			}
		}
	}

	/* Small buffer queue is empty */
	if (stat_r & NS_STAT_SFBQE) {
		int i;
		struct sk_buff *sb;

		writel(NS_STAT_SFBQE, card->membase + STAT);
		printk("nicstar%d: Small free buffer queue empty.\n",
		       card->index);
		for (i = 0; i < card->sbnr.min; i++) {
			sb = dev_alloc_skb(NS_SMSKBSIZE);
			if (sb == NULL) {
				writel(readl(card->membase + CFG) &
				       ~NS_CFG_EFBIE, card->membase + CFG);
				card->efbie = 0;
				break;
			}
			NS_PRV_BUFTYPE(sb) = BUF_SM;
			skb_queue_tail(&card->sbpool.queue, sb);
			skb_reserve(sb, NS_AAL0_HEADER);
			push_rxbufs(card, sb);
		}
		card->sbfqc = i;
		process_rsq(card);
	}

	/* Large buffer queue empty */
	if (stat_r & NS_STAT_LFBQE) {
		int i;
		struct sk_buff *lb;

		writel(NS_STAT_LFBQE, card->membase + STAT);
		printk("nicstar%d: Large free buffer queue empty.\n",
		       card->index);
		for (i = 0; i < card->lbnr.min; i++) {
			lb = dev_alloc_skb(NS_LGSKBSIZE);
			if (lb == NULL) {
				writel(readl(card->membase + CFG) &
				       ~NS_CFG_EFBIE, card->membase + CFG);
				card->efbie = 0;
				break;
			}
			NS_PRV_BUFTYPE(lb) = BUF_LG;
			skb_queue_tail(&card->lbpool.queue, lb);
			skb_reserve(lb, NS_SMBUFSIZE);
			push_rxbufs(card, lb);
		}
		card->lbfqc = i;
		process_rsq(card);
	}

	/* Receive Status Queue is 7/8 full */
	if (stat_r & NS_STAT_RSQAF) {
		writel(NS_STAT_RSQAF, card->membase + STAT);
		RXPRINTK("nicstar%d: RSQ almost full.\n", card->index);
		process_rsq(card);
	}

	spin_unlock_irqrestore(&card->int_lock, flags);
	PRINTK("nicstar%d: end of interrupt service\n", card->index);
	return IRQ_HANDLED;
}