lcs.c

底层驱动开发

/**
 * function called by net device to handle multicast address relevant things
 */
static inline void
lcs_remove_mc_addresses(struct lcs_card *card, struct in_device *in4_dev)
{
	struct ip_mc_list *im4;
	struct list_head *l;
	struct lcs_ipm_list *ipm;
	unsigned long flags;
	char buf[MAX_ADDR_LEN];

	LCS_DBF_TEXT(4, trace, "remmclst");
	spin_lock_irqsave(&card->ipm_lock, flags);
	list_for_each(l, &card->ipm_list) {
		ipm = list_entry(l, struct lcs_ipm_list, list);
		for (im4 = in4_dev->mc_list; im4 != NULL; im4 = im4->next) {
			lcs_get_mac_for_ipm(im4->multiaddr, buf, card->dev);
			if ( (ipm->ipm.ip_addr == im4->multiaddr) &&
			     (memcmp(buf, &ipm->ipm.mac_addr,
				     LCS_MAC_LENGTH) == 0) )
				break;
		}
		if (im4 == NULL)
			ipm->ipm_state = LCS_IPM_STATE_DEL_REQUIRED;
	}
	spin_unlock_irqrestore(&card->ipm_lock, flags);
}

static inline struct lcs_ipm_list *
lcs_check_addr_entry(struct lcs_card *card, struct ip_mc_list *im4, char *buf)
{
	struct lcs_ipm_list *tmp, *ipm = NULL;
	struct list_head *l;
	unsigned long flags;

	LCS_DBF_TEXT(4, trace, "chkmcent");
	spin_lock_irqsave(&card->ipm_lock, flags);
	list_for_each(l, &card->ipm_list) {
		tmp = list_entry(l, struct lcs_ipm_list, list);
		if ( (tmp->ipm.ip_addr == im4->multiaddr) &&
		     (memcmp(buf, &tmp->ipm.mac_addr,
			     LCS_MAC_LENGTH) == 0) ) {
			ipm = tmp;
			break;
		}
	}
	spin_unlock_irqrestore(&card->ipm_lock, flags);
	return ipm;
}

static inline void
lcs_set_mc_addresses(struct lcs_card *card, struct in_device *in4_dev)
{

	struct ip_mc_list *im4;
	struct lcs_ipm_list *ipm;
	char buf[MAX_ADDR_LEN];
	unsigned long flags;

	LCS_DBF_TEXT(4, trace, "setmclst");
	for (im4 = in4_dev->mc_list; im4; im4 = im4->next) {
		lcs_get_mac_for_ipm(im4->multiaddr, buf, card->dev);
		ipm = lcs_check_addr_entry(card, im4, buf);
		if (ipm != NULL)
			continue;	/* Address already in list. */
		ipm = (struct lcs_ipm_list *)
			kmalloc(sizeof(struct lcs_ipm_list), GFP_ATOMIC);
		if (ipm == NULL) {
			PRINT_INFO("Not enough memory to add "
				   "new multicast entry!\n");
			break;
		}
		memset(ipm, 0, sizeof(struct lcs_ipm_list));
		memcpy(&ipm->ipm.mac_addr, buf, LCS_MAC_LENGTH);
		ipm->ipm.ip_addr = im4->multiaddr;
		ipm->ipm_state = LCS_IPM_STATE_SET_REQUIRED;
		spin_lock_irqsave(&card->ipm_lock, flags);
		list_add(&ipm->list, &card->ipm_list);
		spin_unlock_irqrestore(&card->ipm_lock, flags);
	}
}

static int
lcs_register_mc_addresses(void *data)
{
	struct lcs_card *card;
	struct in_device *in4_dev;

	card = (struct lcs_card *) data;
	daemonize("regipm");

	if (!lcs_do_run_thread(card, LCS_SET_MC_THREAD))
		return 0;
	LCS_DBF_TEXT(4, trace, "regmulti");

	in4_dev = in_dev_get(card->dev);
	if (in4_dev == NULL)
		goto out;
	read_lock(&in4_dev->mc_list_lock);
	lcs_remove_mc_addresses(card,in4_dev);
	lcs_set_mc_addresses(card, in4_dev);
	read_unlock(&in4_dev->mc_list_lock);
	in_dev_put(in4_dev);

	lcs_fix_multicast_list(card);
out:
	lcs_clear_thread_running_bit(card, LCS_SET_MC_THREAD);
	return 0;
}
/**
 * function called by net device to
 * handle multicast address relevant things
 */
static void
lcs_set_multicast_list(struct net_device *dev)
{
        struct lcs_card *card;

        LCS_DBF_TEXT(4, trace, "setmulti");
        card = (struct lcs_card *) dev->priv;

        if (!lcs_set_thread_start_bit(card, LCS_SET_MC_THREAD)) {
		schedule_work(&card->kernel_thread_starter);
	}
}

#endif /* CONFIG_IP_MULTICAST */

static long
lcs_check_irb_error(struct ccw_device *cdev, struct irb *irb)
{
	if (!IS_ERR(irb))
		return 0;

	switch (PTR_ERR(irb)) {
	case -EIO:
		PRINT_WARN("i/o-error on device %s\n", cdev->dev.bus_id);
		LCS_DBF_TEXT(2, trace, "ckirberr");
		LCS_DBF_TEXT_(2, trace, "  rc%d", -EIO);
		break;
	case -ETIMEDOUT:
		PRINT_WARN("timeout on device %s\n", cdev->dev.bus_id);
		LCS_DBF_TEXT(2, trace, "ckirberr");
		LCS_DBF_TEXT_(2, trace, "  rc%d", -ETIMEDOUT);
		break;
	default:
		PRINT_WARN("unknown error %ld on device %s\n", PTR_ERR(irb),
			   cdev->dev.bus_id);
		LCS_DBF_TEXT(2, trace, "ckirberr");
		LCS_DBF_TEXT(2, trace, "  rc???");
	}
	return PTR_ERR(irb);
}


/**
 * IRQ Handler for LCS channels
 */
static void
lcs_irq(struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
{
	struct lcs_card *card;
	struct lcs_channel *channel;
	int index;

	if (lcs_check_irb_error(cdev, irb))
		return;

	card = CARD_FROM_DEV(cdev);
	if (card->read.ccwdev == cdev)
		channel = &card->read;
	else
		channel = &card->write;

	LCS_DBF_TEXT_(5, trace, "Rint%s",cdev->dev.bus_id);
	LCS_DBF_TEXT_(5, trace, "%4x%4x",irb->scsw.cstat, irb->scsw.dstat);
	LCS_DBF_TEXT_(5, trace, "%4x%4x",irb->scsw.fctl, irb->scsw.actl);

	/* How far in the ccw chain have we processed? */
	if ((channel->state != CH_STATE_INIT) &&
	    (irb->scsw.fctl & SCSW_FCTL_START_FUNC)) {
		index = (struct ccw1 *) __va((addr_t) irb->scsw.cpa) 
			- channel->ccws;
		if ((irb->scsw.actl & SCSW_ACTL_SUSPENDED) ||
		    (irb->scsw.cstat | SCHN_STAT_PCI))
			/* Bloody io subsystem tells us lies about cpa... */
			index = (index - 1) & (LCS_NUM_BUFFS - 1);
		while (channel->io_idx != index) {
			__lcs_processed_buffer(channel,
					       channel->iob + channel->io_idx);
			channel->io_idx =
				(channel->io_idx + 1) & (LCS_NUM_BUFFS - 1);
		}
	}

	if ((irb->scsw.dstat & DEV_STAT_DEV_END) ||
	    (irb->scsw.dstat & DEV_STAT_CHN_END) ||
	    (irb->scsw.dstat & DEV_STAT_UNIT_CHECK))
		/* Mark channel as stopped. */
		channel->state = CH_STATE_STOPPED;
	else if (irb->scsw.actl & SCSW_ACTL_SUSPENDED)
		/* CCW execution stopped on a suspend bit. */
		channel->state = CH_STATE_SUSPENDED;

	if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC) {
		if (irb->scsw.cc != 0) {
			ccw_device_halt(channel->ccwdev, (addr_t) channel);
			return;
		}
		/* The channel has been stopped by halt_IO. */
		channel->state = CH_STATE_HALTED;
	}

	if (irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
		channel->state = CH_STATE_CLEARED;
	}
	/* Do the rest in the tasklet. */
	tasklet_schedule(&channel->irq_tasklet);
}

/**
 * Tasklet for IRQ handler
 */
static void
lcs_tasklet(unsigned long data)
{
	unsigned long flags;
	struct lcs_channel *channel;
	struct lcs_buffer *iob;
	int buf_idx;
	int rc;

	channel = (struct lcs_channel *) data;
	LCS_DBF_TEXT_(5, trace, "tlet%s",channel->ccwdev->dev.bus_id);

	/* Check for processed buffers. */
	iob = channel->iob;
	buf_idx = channel->buf_idx;
	while (iob[buf_idx].state == BUF_STATE_PROCESSED) {
		/* Do the callback thing. */
		if (iob[buf_idx].callback != NULL)
			iob[buf_idx].callback(channel, iob + buf_idx);
		buf_idx = (buf_idx + 1) & (LCS_NUM_BUFFS - 1);
	}
	channel->buf_idx = buf_idx;

	if (channel->state == CH_STATE_STOPPED)
		// FIXME: what if rc != 0 ??
		rc = lcs_start_channel(channel);
	spin_lock_irqsave(get_ccwdev_lock(channel->ccwdev), flags);
	if (channel->state == CH_STATE_SUSPENDED &&
	    channel->iob[channel->io_idx].state == BUF_STATE_READY) {
		// FIXME: what if rc != 0 ??
		rc = __lcs_resume_channel(channel);
	}
	spin_unlock_irqrestore(get_ccwdev_lock(channel->ccwdev), flags);

	/* Something happened on the channel. Wake up waiters. */
	wake_up(&channel->wait_q);
}

/**
 * Finish current tx buffer and make it ready for transmit.
 */
static void
__lcs_emit_txbuffer(struct lcs_card *card)
{
	LCS_DBF_TEXT(5, trace, "emittx");
	*(__u16 *)(card->tx_buffer->data + card->tx_buffer->count) = 0;
	card->tx_buffer->count += 2;
	lcs_ready_buffer(&card->write, card->tx_buffer);
	card->tx_buffer = NULL;
	card->tx_emitted++;
}

/**
 * Callback for finished tx buffers.
 */
static void
lcs_txbuffer_cb(struct lcs_channel *channel, struct lcs_buffer *buffer)
{
	struct lcs_card *card;

	LCS_DBF_TEXT(5, trace, "txbuffcb");
	/* Put buffer back to pool. */
	lcs_release_buffer(channel, buffer);
	card = (struct lcs_card *)
		((char *) channel - offsetof(struct lcs_card, write));
	spin_lock(&card->lock);
	card->tx_emitted--;
	if (card->tx_emitted <= 0 && card->tx_buffer != NULL)
		/*
		 * Last running tx buffer has finished. Submit partially
		 * filled current buffer.
		 */
		__lcs_emit_txbuffer(card);
	spin_unlock(&card->lock);
}

/**
 * Packet transmit function called by network stack
 */
static int
__lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb,
		 struct net_device *dev)
{
	struct lcs_header *header;

	LCS_DBF_TEXT(5, trace, "hardxmit");
	if (skb == NULL) {
		card->stats.tx_dropped++;
		card->stats.tx_errors++;
		return -EIO;
	}
	if (card->state != DEV_STATE_UP) {
		dev_kfree_skb(skb);
		card->stats.tx_dropped++;
		card->stats.tx_errors++;
		card->stats.tx_carrier_errors++;
		return 0;
	}
	if (netif_queue_stopped(dev) ) {
		card->stats.tx_dropped++;
		return -EBUSY;
	}
	if (card->tx_buffer != NULL &&
	    card->tx_buffer->count + sizeof(struct lcs_header) +
	    skb->len + sizeof(u16) > LCS_IOBUFFERSIZE)
		/* skb too big for current tx buffer. */
		__lcs_emit_txbuffer(card);
	if (card->tx_buffer == NULL) {
		/* Get new tx buffer */
		card->tx_buffer = lcs_get_buffer(&card->write);
		if (card->tx_buffer == NULL) {
			card->stats.tx_dropped++;
			return -EBUSY;
		}
		card->tx_buffer->callback = lcs_txbuffer_cb;
		card->tx_buffer->count = 0;
	}
	header = (struct lcs_header *)
		(card->tx_buffer->data + card->tx_buffer->count);
	card->tx_buffer->count += skb->len + sizeof(struct lcs_header);
	header->offset = card->tx_buffer->count;
	header->type = card->lan_type;
	header->slot = card->portno;
	memcpy(header + 1, skb->data, skb->len);
	card->stats.tx_bytes += skb->len;
	card->stats.tx_packets++;
	dev_kfree_skb(skb);
	if (card->tx_emitted <= 0)
		/* If this is the first tx buffer emit it immediately. */
		__lcs_emit_txbuffer(card);
	return 0;
}

static int
lcs_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct lcs_card *card;
	int rc;

	LCS_DBF_TEXT(5, trace, "pktxmit");
	card = (struct lcs_card *) dev->priv;
	spin_lock(&card->lock);
	rc = __lcs_start_xmit(card, skb, dev);
	spin_unlock(&card->lock);
	return rc;
}

/**
 * send startlan and lanstat command to make LCS device ready
 */
static int
lcs_startlan_auto(struct lcs_card *card)
{
	int rc;

	LCS_DBF_TEXT(2, trace, "strtauto");
#ifdef CONFIG_NET_ETHERNET
	card->lan_type = LCS_FRAME_TYPE_ENET;
	rc = lcs_send_startlan(card, LCS_INITIATOR_TCPIP);
	if (rc == 0)
		return 0;

#endif
#ifdef CONFIG_TR
	card->lan_type = LCS_FRAME_TYPE_TR;
	rc = lcs_send_startlan(card, LCS_INITIATOR_TCPIP);
	if (rc == 0)
		return 0;
#endif
#ifdef CONFIG_FDDI
	card->lan_type = LCS_FRAME_TYPE_FDDI;
	rc = lcs_send_startlan(card, LCS_INITIATOR_TCPIP);
	if (rc == 0)
		return 0;
#endif
	return -EIO;
}

static int
lcs_startlan(struct lcs_card *card)
{
	int rc, i;

	LCS_DBF_TEXT(2, trace, "startlan");
	rc = 0;
	if (card->portno != LCS_INVALID_PORT_NO) {
		if (card->lan_type == LCS_FRAME_TYPE_AUTO)
			rc = lcs_startlan_auto(card);
		else
			rc = lcs_send_startlan(card, LCS_INITIATOR_TCPIP);
	} else {
                for (i = 0; i <= 16; i++) {
                        card->portno = i;
                        if (card->lan_type != LCS_FRAME_TYPE_AUTO)
                                rc = lcs_send_startlan(card,
                                                       LCS_INITIATOR_TCPIP);
                        else
                                /* autodetecting lan type */
                                rc = lcs_startlan_auto(card);
                        if (rc == 0)
                                break;
                }
        }
	if (rc == 0)
		return lcs_send_lanstat(card);
	return rc;
}

/**
 * LCS detect function
 * setup channels and make them I/O ready
 */
static int
lcs_detect(struct lcs_card *card)
{
	int rc = 0;

	LCS_DBF_TEXT(2, setup, "lcsdetct");
	/* start/reset card */
	if (card->dev)
		netif_stop_queue(card->dev);
	rc = lcs_stop_channels(card);
	if (rc == 0) {
		rc = lcs_start_channels(card);
		if (rc == 0) {
			rc = lcs_send_startup(card, LCS_INITIATOR_TCPIP);
			if (rc == 0)
				rc = lcs_startlan(card);
		}
	}
	if (rc == 0) {
		card->state = DEV_STATE_UP;
	} else {
		card->state = DEV_STATE_DOWN;
		card->write.state = CH_STATE_INIT;
		card->read.state =  CH_STATE_INIT;
	}
	return rc;
}

/**
 * reset card
 */
static int
lcs_resetcard(struct lcs_card *card)
{
	int retries;

	LCS_DBF_TEXT(2, trace, "rescard");
	for (retries = 0; retries < 10; retries++) {
		if (lcs_detect(card) == 0) {
			netif_wake_queue(card->dev);
			card->state = DEV_STATE_UP;
			PRINT_INFO("LCS device %s successfully restarted!\n",
				   card->dev->name);
			return 0;
		}
		msleep(3000);
	}
	PRINT_ERR("Error in Reseting LCS card!\n");
	return -EIO;
}


/**
 * LCS Stop card
 */
static int
lcs_stopcard(struct lcs_card *card)
{
	int rc;

	LCS_DBF_TEXT(3, setup, "stopcard");

	if (card->read.state != CH_STATE_STOPPED &&
	    card->write.state != CH_STATE_STOPPED &&
	    card->state == DEV_STATE_UP) {
		lcs_clear_multicast_list(card);
		rc = lcs_send_stoplan(card,LCS_INITIATOR_TCPIP);
		rc = lcs_send_shutdown(card);
	}
	rc = lcs_stop_channels(card);
	card->state = DEV_STATE_DOWN;

	return rc;
}

/**
 * LGW initiated commands
 */
static int
lcs_lgw_startlan_thread(void *data)
{
	struct lcs_card *card;

	card = (struct lcs_card *) data;
	daemonize("lgwstpln");

	if (!lcs_do_run_thread(card, LCS_STARTLAN_THREAD))
		return 0;
	LCS_DBF_TEXT(4, trace, "lgwstpln");
	if (card->dev)
		netif_stop_queue(card->dev);
	if (lcs_startlan(card) == 0) {
		netif_wake_queue(card->dev);
		card->state = DEV_STATE_UP;
		PRINT_INFO("LCS Startlan for device %s succeeded!\n",
			   card->dev->name);

	} else
		PRINT_ERR("LCS Startlan for device %s failed!\n",
			  card->dev->name);
	lcs_clear_thread_running_bit(card, LCS_STARTLAN_THREAD);
	return 0;
}

/**
 * Send startup command initiated by Lan Gateway
 */
static int
lcs_lgw_startup_thread(void *data)
{
	int rc;

	struct lcs_card *card;

	card = (struct lcs_card *) data;
	daemonize("lgwstaln");

	if (!lcs_do_run_thread(card, LCS_STARTUP_THREAD))
		return 0;
	LCS_DBF_TEXT(4, trace, "lgwstaln");
	if (card->dev)
		netif_stop_queue(card->dev);
	rc = lcs_send_startup(card, LCS_INITIATOR_LGW);
	if (rc != 0) {
		PRINT_ERR("Startup for LCS device %s initiated " \
			  "by LGW failed!\nReseting card ...\n",
			  card->dev->name);
		/* do a card reset */
		rc = lcs_resetcard(card);
		if (rc == 0)
			goto Done;
	}
	rc = lcs_startlan(card);
	if (rc == 0) {
		netif_wake_queue(card->dev);
		card->state = DEV_STATE_UP;
	}
Done:
	if (rc == 0)
		PRINT_INFO("LCS Startup for device %s succeeded!\n",
			   card->dev->name);
	else
		PRINT_ERR("LCS Startup for device %s failed!\n",
			  card->dev->name);
	lcs_clear_thread_running_bit(card, LCS_STARTUP_THREAD);
	return 0;
}


/**
 * send stoplan command initiated by Lan Gateway
 */