acenic.c

linux 内核源代码

	ap = netdev_priv(dev);

	while (evtcsm != evtprd) {
		switch (ap->evt_ring[evtcsm].evt) {
		case E_FW_RUNNING:
			printk(KERN_INFO "%s: Firmware up and running\n",
			       ap->name);
			ap->fw_running = 1;
			wmb();
			break;
		case E_STATS_UPDATED:
			break;
		case E_LNK_STATE:
		{
			u16 code = ap->evt_ring[evtcsm].code;
			switch (code) {
			case E_C_LINK_UP:
			{
				u32 state = readl(&ap->regs->GigLnkState);
				printk(KERN_WARNING "%s: Optical link UP "
				       "(%s Duplex, Flow Control: %s%s)\n",
				       ap->name,
				       state & LNK_FULL_DUPLEX ? "Full":"Half",
				       state & LNK_TX_FLOW_CTL_Y ? "TX " : "",
				       state & LNK_RX_FLOW_CTL_Y ? "RX" : "");
				break;
			}
			case E_C_LINK_DOWN:
				printk(KERN_WARNING "%s: Optical link DOWN\n",
				       ap->name);
				break;
			case E_C_LINK_10_100:
				printk(KERN_WARNING "%s: 10/100BaseT link "
				       "UP\n", ap->name);
				break;
			default:
				printk(KERN_ERR "%s: Unknown optical link "
				       "state %02x\n", ap->name, code);
			}
			break;
		}
		case E_ERROR:
			switch(ap->evt_ring[evtcsm].code) {
			case E_C_ERR_INVAL_CMD:
				printk(KERN_ERR "%s: invalid command error\n",
				       ap->name);
				break;
			case E_C_ERR_UNIMP_CMD:
				printk(KERN_ERR "%s: unimplemented command "
				       "error\n", ap->name);
				break;
			case E_C_ERR_BAD_CFG:
				printk(KERN_ERR "%s: bad config error\n",
				       ap->name);
				break;
			default:
				printk(KERN_ERR "%s: unknown error %02x\n",
				       ap->name, ap->evt_ring[evtcsm].code);
			}
			break;
		case E_RESET_JUMBO_RNG:
		{
			int i;
			for (i = 0; i < RX_JUMBO_RING_ENTRIES; i++) {
				if (ap->skb->rx_jumbo_skbuff[i].skb) {
					ap->rx_jumbo_ring[i].size = 0;
					set_aceaddr(&ap->rx_jumbo_ring[i].addr, 0);
					dev_kfree_skb(ap->skb->rx_jumbo_skbuff[i].skb);
					ap->skb->rx_jumbo_skbuff[i].skb = NULL;
				}
			}

 			if (ACE_IS_TIGON_I(ap)) {
 				struct cmd cmd;
 				cmd.evt = C_SET_RX_JUMBO_PRD_IDX;
 				cmd.code = 0;
 				cmd.idx = 0;
 				ace_issue_cmd(ap->regs, &cmd);
 			} else {
 				writel(0, &((ap->regs)->RxJumboPrd));
 				wmb();
 			}

			ap->jumbo = 0;
			ap->rx_jumbo_skbprd = 0;
			printk(KERN_INFO "%s: Jumbo ring flushed\n",
			       ap->name);
			clear_bit(0, &ap->jumbo_refill_busy);
			break;
		}
		default:
			printk(KERN_ERR "%s: Unhandled event 0x%02x\n",
			       ap->name, ap->evt_ring[evtcsm].evt);
		}
		evtcsm = (evtcsm + 1) % EVT_RING_ENTRIES;
	}

	return evtcsm;
}


static void ace_rx_int(struct net_device *dev, u32 rxretprd, u32 rxretcsm)
{
	struct ace_private *ap = netdev_priv(dev);
	u32 idx;
	int mini_count = 0, std_count = 0;

	idx = rxretcsm;

	prefetchw(&ap->cur_rx_bufs);
	prefetchw(&ap->cur_mini_bufs);

	while (idx != rxretprd) {
		struct ring_info *rip;
		struct sk_buff *skb;
		struct rx_desc *rxdesc, *retdesc;
		u32 skbidx;
		int bd_flags, desc_type, mapsize;
		u16 csum;


		/* make sure the rx descriptor isn't read before rxretprd */
		if (idx == rxretcsm)
			rmb();

		retdesc = &ap->rx_return_ring[idx];
		skbidx = retdesc->idx;
		bd_flags = retdesc->flags;
		desc_type = bd_flags & (BD_FLG_JUMBO | BD_FLG_MINI);

		switch(desc_type) {
			/*
			 * Normal frames do not have any flags set
			 *
			 * Mini and normal frames arrive frequently,
			 * so use a local counter to avoid doing
			 * atomic operations for each packet arriving.
			 */
		case 0:
			rip = &ap->skb->rx_std_skbuff[skbidx];
			mapsize = ACE_STD_BUFSIZE;
			rxdesc = &ap->rx_std_ring[skbidx];
			std_count++;
			break;
		case BD_FLG_JUMBO:
			rip = &ap->skb->rx_jumbo_skbuff[skbidx];
			mapsize = ACE_JUMBO_BUFSIZE;
			rxdesc = &ap->rx_jumbo_ring[skbidx];
			atomic_dec(&ap->cur_jumbo_bufs);
			break;
		case BD_FLG_MINI:
			rip = &ap->skb->rx_mini_skbuff[skbidx];
			mapsize = ACE_MINI_BUFSIZE;
			rxdesc = &ap->rx_mini_ring[skbidx];
			mini_count++;
			break;
		default:
			printk(KERN_INFO "%s: unknown frame type (0x%02x) "
			       "returned by NIC\n", dev->name,
			       retdesc->flags);
			goto error;
		}

		skb = rip->skb;
		rip->skb = NULL;
		pci_unmap_page(ap->pdev,
			       pci_unmap_addr(rip, mapping),
			       mapsize,
			       PCI_DMA_FROMDEVICE);
		skb_put(skb, retdesc->size);

		/*
		 * Fly baby, fly!
		 */
		csum = retdesc->tcp_udp_csum;

		skb->protocol = eth_type_trans(skb, dev);

		/*
		 * Instead of forcing the poor tigon mips cpu to calculate
		 * pseudo hdr checksum, we do this ourselves.
		 */
		if (bd_flags & BD_FLG_TCP_UDP_SUM) {
			skb->csum = htons(csum);
			skb->ip_summed = CHECKSUM_COMPLETE;
		} else {
			skb->ip_summed = CHECKSUM_NONE;
		}

		/* send it up */
#if ACENIC_DO_VLAN
		if (ap->vlgrp && (bd_flags & BD_FLG_VLAN_TAG)) {
			vlan_hwaccel_rx(skb, ap->vlgrp, retdesc->vlan);
		} else
#endif
			netif_rx(skb);

		dev->last_rx = jiffies;
		ap->stats.rx_packets++;
		ap->stats.rx_bytes += retdesc->size;

		idx = (idx + 1) % RX_RETURN_RING_ENTRIES;
	}

	atomic_sub(std_count, &ap->cur_rx_bufs);
	if (!ACE_IS_TIGON_I(ap))
		atomic_sub(mini_count, &ap->cur_mini_bufs);

 out:
	/*
	 * According to the documentation RxRetCsm is obsolete with
	 * the 12.3.x Firmware - my Tigon I NICs seem to disagree!
	 */
	if (ACE_IS_TIGON_I(ap)) {
		writel(idx, &ap->regs->RxRetCsm);
	}
	ap->cur_rx = idx;

	return;
 error:
	idx = rxretprd;
	goto out;
}


static inline void ace_tx_int(struct net_device *dev,
			      u32 txcsm, u32 idx)
{
	struct ace_private *ap = netdev_priv(dev);

	do {
		struct sk_buff *skb;
		dma_addr_t mapping;
		struct tx_ring_info *info;

		info = ap->skb->tx_skbuff + idx;
		skb = info->skb;
		mapping = pci_unmap_addr(info, mapping);

		if (mapping) {
			pci_unmap_page(ap->pdev, mapping,
				       pci_unmap_len(info, maplen),
				       PCI_DMA_TODEVICE);
			pci_unmap_addr_set(info, mapping, 0);
		}

		if (skb) {
			ap->stats.tx_packets++;
			ap->stats.tx_bytes += skb->len;
			dev_kfree_skb_irq(skb);
			info->skb = NULL;
		}

		idx = (idx + 1) % ACE_TX_RING_ENTRIES(ap);
	} while (idx != txcsm);

	if (netif_queue_stopped(dev))
		netif_wake_queue(dev);

	wmb();
	ap->tx_ret_csm = txcsm;

	/* So... tx_ret_csm is advanced _after_ check for device wakeup.
	 *
	 * We could try to make it before. In this case we would get
	 * the following race condition: hard_start_xmit on other cpu
	 * enters after we advanced tx_ret_csm and fills space,
	 * which we have just freed, so that we make illegal device wakeup.
	 * There is no good way to workaround this (at entry
	 * to ace_start_xmit detects this condition and prevents
	 * ring corruption, but it is not a good workaround.)
	 *
	 * When tx_ret_csm is advanced after, we wake up device _only_
	 * if we really have some space in ring (though the core doing
	 * hard_start_xmit can see full ring for some period and has to
	 * synchronize.) Superb.
	 * BUT! We get another subtle race condition. hard_start_xmit
	 * may think that ring is full between wakeup and advancing
	 * tx_ret_csm and will stop device instantly! It is not so bad.
	 * We are guaranteed that there is something in ring, so that
	 * the next irq will resume transmission. To speedup this we could
	 * mark descriptor, which closes ring with BD_FLG_COAL_NOW
	 * (see ace_start_xmit).
	 *
	 * Well, this dilemma exists in all lock-free devices.
	 * We, following scheme used in drivers by Donald Becker,
	 * select the least dangerous.
	 *							--ANK
	 */
}


static irqreturn_t ace_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct ace_private *ap = netdev_priv(dev);
	struct ace_regs __iomem *regs = ap->regs;
	u32 idx;
	u32 txcsm, rxretcsm, rxretprd;
	u32 evtcsm, evtprd;

	/*
	 * In case of PCI shared interrupts or spurious interrupts,
	 * we want to make sure it is actually our interrupt before
	 * spending any time in here.
	 */
	if (!(readl(&regs->HostCtrl) & IN_INT))
		return IRQ_NONE;

	/*
	 * ACK intr now. Otherwise we will lose updates to rx_ret_prd,
	 * which happened _after_ rxretprd = *ap->rx_ret_prd; but before
	 * writel(0, &regs->Mb0Lo).
	 *
	 * "IRQ avoidance" recommended in docs applies to IRQs served
	 * threads and it is wrong even for that case.
	 */
	writel(0, &regs->Mb0Lo);
	readl(&regs->Mb0Lo);

	/*
	 * There is no conflict between transmit handling in
	 * start_xmit and receive processing, thus there is no reason
	 * to take a spin lock for RX handling. Wait until we start
	 * working on the other stuff - hey we don't need a spin lock
	 * anymore.
	 */
	rxretprd = *ap->rx_ret_prd;
	rxretcsm = ap->cur_rx;

	if (rxretprd != rxretcsm)
		ace_rx_int(dev, rxretprd, rxretcsm);

	txcsm = *ap->tx_csm;
	idx = ap->tx_ret_csm;

	if (txcsm != idx) {
		/*
		 * If each skb takes only one descriptor this check degenerates
		 * to identity, because new space has just been opened.
		 * But if skbs are fragmented we must check that this index
		 * update releases enough of space, otherwise we just
		 * wait for device to make more work.
		 */
		if (!tx_ring_full(ap, txcsm, ap->tx_prd))
			ace_tx_int(dev, txcsm, idx);
	}

	evtcsm = readl(&regs->EvtCsm);
	evtprd = *ap->evt_prd;

	if (evtcsm != evtprd) {
		evtcsm = ace_handle_event(dev, evtcsm, evtprd);
		writel(evtcsm, &regs->EvtCsm);
	}

	/*
	 * This has to go last in the interrupt handler and run with
	 * the spin lock released ... what lock?
	 */
	if (netif_running(dev)) {
		int cur_size;
		int run_tasklet = 0;

		cur_size = atomic_read(&ap->cur_rx_bufs);
		if (cur_size < RX_LOW_STD_THRES) {
			if ((cur_size < RX_PANIC_STD_THRES) &&
			    !test_and_set_bit(0, &ap->std_refill_busy)) {
#ifdef DEBUG
				printk("low on std buffers %i\n", cur_size);
#endif
				ace_load_std_rx_ring(ap,
						     RX_RING_SIZE - cur_size);
			} else
				run_tasklet = 1;
		}

		if (!ACE_IS_TIGON_I(ap)) {
			cur_size = atomic_read(&ap->cur_mini_bufs);
			if (cur_size < RX_LOW_MINI_THRES) {
				if ((cur_size < RX_PANIC_MINI_THRES) &&
				    !test_and_set_bit(0,
						      &ap->mini_refill_busy)) {
#ifdef DEBUG
					printk("low on mini buffers %i\n",
					       cur_size);
#endif
					ace_load_mini_rx_ring(ap, RX_MINI_SIZE - cur_size);
				} else
					run_tasklet = 1;
			}
		}

		if (ap->jumbo) {
			cur_size = atomic_read(&ap->cur_jumbo_bufs);
			if (cur_size < RX_LOW_JUMBO_THRES) {
				if ((cur_size < RX_PANIC_JUMBO_THRES) &&
				    !test_and_set_bit(0,
						      &ap->jumbo_refill_busy)){
#ifdef DEBUG
					printk("low on jumbo buffers %i\n",
					       cur_size);
#endif
					ace_load_jumbo_rx_ring(ap, RX_JUMBO_SIZE - cur_size);
				} else
					run_tasklet = 1;
			}
		}
		if (run_tasklet && !ap->tasklet_pending) {
			ap->tasklet_pending = 1;
			tasklet_schedule(&ap->ace_tasklet);
		}
	}

	return IRQ_HANDLED;
}


#if ACENIC_DO_VLAN
static void ace_vlan_rx_register(struct net_device *dev, struct vlan_group *grp)
{
	struct ace_private *ap = netdev_priv(dev);
	unsigned long flags;

	local_irq_save(flags);
	ace_mask_irq(dev);

	ap->vlgrp = grp;

	ace_unmask_irq(dev);
	local_irq_restore(flags);
}
#endif /* ACENIC_DO_VLAN */


static int ace_open(struct net_device *dev)
{
	struct ace_private *ap = netdev_priv(dev);
	struct ace_regs __iomem *regs = ap->regs;
	struct cmd cmd;

	if (!(ap->fw_running)) {
		printk(KERN_WARNING "%s: Firmware not running!\n", dev->name);
		return -EBUSY;
	}

	writel(dev->mtu + ETH_HLEN + 4, &regs->IfMtu);

	cmd.evt = C_CLEAR_STATS;
	cmd.code = 0;
	cmd.idx = 0;
	ace_issue_cmd(regs, &cmd);

	cmd.evt = C_HOST_STATE;
	cmd.code = C_C_STACK_UP;
	cmd.idx = 0;
	ace_issue_cmd