lcs.c

底层驱动开发

 */
static int
lcs_stop_channels(struct lcs_card *card)
{
	LCS_DBF_TEXT(2, trace, "chhalt");
	lcs_stop_channel(&card->read);
	lcs_stop_channel(&card->write);
	return 0;
}

/**
 * Get empty buffer.
 */
static struct lcs_buffer *
__lcs_get_buffer(struct lcs_channel *channel)
{
	int index;

	LCS_DBF_TEXT(5, trace, "_getbuff");
	index = channel->io_idx;
	do {
		if (channel->iob[index].state == BUF_STATE_EMPTY) {
			channel->iob[index].state = BUF_STATE_LOCKED;
			return channel->iob + index;
		}
		index = (index + 1) & (LCS_NUM_BUFFS - 1);
	} while (index != channel->io_idx);
	return NULL;
}

static struct lcs_buffer *
lcs_get_buffer(struct lcs_channel *channel)
{
	struct lcs_buffer *buffer;
	unsigned long flags;

	LCS_DBF_TEXT(5, trace, "getbuff");
	spin_lock_irqsave(get_ccwdev_lock(channel->ccwdev), flags);
	buffer = __lcs_get_buffer(channel);
	spin_unlock_irqrestore(get_ccwdev_lock(channel->ccwdev), flags);
	return buffer;
}

/**
 * Resume channel program if the channel is suspended.
 */
static int
__lcs_resume_channel(struct lcs_channel *channel)
{
	int rc;

	if (channel->state != CH_STATE_SUSPENDED)
		return 0;
	if (channel->ccws[channel->io_idx].flags & CCW_FLAG_SUSPEND)
		return 0;
	LCS_DBF_TEXT_(5, trace, "rsch%s", channel->ccwdev->dev.bus_id);
	rc = ccw_device_resume(channel->ccwdev);
	if (rc) {
		LCS_DBF_TEXT_(4, trace, "ersc%s", channel->ccwdev->dev.bus_id);
		PRINT_ERR("Error in lcs_resume_channel: rc=%d\n",rc);
	} else
		channel->state = CH_STATE_RUNNING;
	return rc;

}

/**
 * Make a buffer ready for processing.
 */
static inline void
__lcs_ready_buffer_bits(struct lcs_channel *channel, int index)
{
	int prev, next;

	LCS_DBF_TEXT(5, trace, "rdybits");
	prev = (index - 1) & (LCS_NUM_BUFFS - 1);
	next = (index + 1) & (LCS_NUM_BUFFS - 1);
	/* Check if we may clear the suspend bit of this buffer. */
	if (channel->ccws[next].flags & CCW_FLAG_SUSPEND) {
		/* Check if we have to set the PCI bit. */
		if (!(channel->ccws[prev].flags & CCW_FLAG_SUSPEND))
			/* Suspend bit of the previous buffer is not set. */
			channel->ccws[index].flags |= CCW_FLAG_PCI;
		/* Suspend bit of the next buffer is set. */
		channel->ccws[index].flags &= ~CCW_FLAG_SUSPEND;
	}
}

static int
lcs_ready_buffer(struct lcs_channel *channel, struct lcs_buffer *buffer)
{
	unsigned long flags;
	int index, rc;

	LCS_DBF_TEXT(5, trace, "rdybuff");
	if (buffer->state != BUF_STATE_LOCKED &&
	    buffer->state != BUF_STATE_PROCESSED)
		BUG();
	spin_lock_irqsave(get_ccwdev_lock(channel->ccwdev), flags);
	buffer->state = BUF_STATE_READY;
	index = buffer - channel->iob;
	/* Set length. */
	channel->ccws[index].count = buffer->count;
	/* Check relevant PCI/suspend bits. */
	__lcs_ready_buffer_bits(channel, index);
	rc = __lcs_resume_channel(channel);
	spin_unlock_irqrestore(get_ccwdev_lock(channel->ccwdev), flags);
	return rc;
}

/**
 * Mark the buffer as processed. Take care of the suspend bit
 * of the previous buffer. This function is called from
 * interrupt context, so the lock must not be taken.
 */
static int
__lcs_processed_buffer(struct lcs_channel *channel, struct lcs_buffer *buffer)
{
	int index, prev, next;

	LCS_DBF_TEXT(5, trace, "prcsbuff");
	if (buffer->state != BUF_STATE_READY)
		BUG();
	buffer->state = BUF_STATE_PROCESSED;
	index = buffer - channel->iob;
	prev = (index - 1) & (LCS_NUM_BUFFS - 1);
	next = (index + 1) & (LCS_NUM_BUFFS - 1);
	/* Set the suspend bit and clear the PCI bit of this buffer. */
	channel->ccws[index].flags |= CCW_FLAG_SUSPEND;
	channel->ccws[index].flags &= ~CCW_FLAG_PCI;
	/* Check the suspend bit of the previous buffer. */
	if (channel->iob[prev].state == BUF_STATE_READY) {
		/*
		 * Previous buffer is in state ready. It might have
		 * happened in lcs_ready_buffer that the suspend bit
		 * has not been cleared to avoid an endless loop.
		 * Do it now.
		 */
		__lcs_ready_buffer_bits(channel, prev);
	}
	/* Clear PCI bit of next buffer. */
	channel->ccws[next].flags &= ~CCW_FLAG_PCI;
	return __lcs_resume_channel(channel);
}

/**
 * Put a processed buffer back to state empty.
 */
static void
lcs_release_buffer(struct lcs_channel *channel, struct lcs_buffer *buffer)
{
	unsigned long flags;

	LCS_DBF_TEXT(5, trace, "relbuff");
	if (buffer->state != BUF_STATE_LOCKED &&
	    buffer->state != BUF_STATE_PROCESSED)
		BUG();
	spin_lock_irqsave(get_ccwdev_lock(channel->ccwdev), flags);
	buffer->state = BUF_STATE_EMPTY;
	spin_unlock_irqrestore(get_ccwdev_lock(channel->ccwdev), flags);
}

/**
 * Get buffer for a lan command.
 */
static struct lcs_buffer *
lcs_get_lancmd(struct lcs_card *card, int count)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(4, trace, "getlncmd");
	/* Get buffer and wait if none is available. */
	wait_event(card->write.wait_q,
		   ((buffer = lcs_get_buffer(&card->write)) != NULL));
	count += sizeof(struct lcs_header);
	*(__u16 *)(buffer->data + count) = 0;
	buffer->count = count + sizeof(__u16);
	buffer->callback = lcs_release_buffer;
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->offset = count;
	cmd->type = LCS_FRAME_TYPE_CONTROL;
	cmd->slot = 0;
	return buffer;
}


static void
lcs_get_reply(struct lcs_reply *reply)
{
	WARN_ON(atomic_read(&reply->refcnt) <= 0);
	atomic_inc(&reply->refcnt);
}

static void
lcs_put_reply(struct lcs_reply *reply)
{
        WARN_ON(atomic_read(&reply->refcnt) <= 0);
        if (atomic_dec_and_test(&reply->refcnt)) {
		kfree(reply);
	}

}

static struct lcs_reply *
lcs_alloc_reply(struct lcs_cmd *cmd)
{
	struct lcs_reply *reply;

	LCS_DBF_TEXT(4, trace, "getreply");

	reply = kmalloc(sizeof(struct lcs_reply), GFP_ATOMIC);
	if (!reply)
		return NULL;
	memset(reply,0,sizeof(struct lcs_reply));
	atomic_set(&reply->refcnt,1);
	reply->sequence_no = cmd->sequence_no;
	reply->received = 0;
	reply->rc = 0;
	init_waitqueue_head(&reply->wait_q);

	return reply;
}

/**
 * Notifier function for lancmd replies. Called from read irq.
 */
static void
lcs_notify_lancmd_waiters(struct lcs_card *card, struct lcs_cmd *cmd)
{
	struct list_head *l, *n;
	struct lcs_reply *reply;

	LCS_DBF_TEXT(4, trace, "notiwait");
	spin_lock(&card->lock);
	list_for_each_safe(l, n, &card->lancmd_waiters) {
		reply = list_entry(l, struct lcs_reply, list);
		if (reply->sequence_no == cmd->sequence_no) {
			lcs_get_reply(reply);
			list_del_init(&reply->list);
			if (reply->callback != NULL)
				reply->callback(card, cmd);
			reply->received = 1;
			reply->rc = cmd->return_code;
			wake_up(&reply->wait_q);
			lcs_put_reply(reply);
			break;
		}
	}
	spin_unlock(&card->lock);
}

/**
 * Emit buffer of a lan comand.
 */
void
lcs_lancmd_timeout(unsigned long data)
{
	struct lcs_reply *reply, *list_reply, *r;
	unsigned long flags;

	LCS_DBF_TEXT(4, trace, "timeout");
	reply = (struct lcs_reply *) data;
	spin_lock_irqsave(&reply->card->lock, flags);
	list_for_each_entry_safe(list_reply, r,
				 &reply->card->lancmd_waiters,list) {
		if (reply == list_reply) {
			lcs_get_reply(reply);
			list_del_init(&reply->list);
			spin_unlock_irqrestore(&reply->card->lock, flags);
			reply->received = 1;
			reply->rc = -ETIME;
			wake_up(&reply->wait_q);
			lcs_put_reply(reply);
			return;
		}
	}
	spin_unlock_irqrestore(&reply->card->lock, flags);
}

static int
lcs_send_lancmd(struct lcs_card *card, struct lcs_buffer *buffer,
		void (*reply_callback)(struct lcs_card *, struct lcs_cmd *))
{
	struct lcs_reply *reply;
	struct lcs_cmd *cmd;
	struct timer_list timer;
	unsigned long flags;
	int rc;

	LCS_DBF_TEXT(4, trace, "sendcmd");
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->return_code = 0;
	cmd->sequence_no = card->sequence_no++;
	reply = lcs_alloc_reply(cmd);
	if (!reply)
		return -ENOMEM;
	reply->callback = reply_callback;
	reply->card = card;
	spin_lock_irqsave(&card->lock, flags);
	list_add_tail(&reply->list, &card->lancmd_waiters);
	spin_unlock_irqrestore(&card->lock, flags);

	buffer->callback = lcs_release_buffer;
	rc = lcs_ready_buffer(&card->write, buffer);
	if (rc)
		return rc;
	init_timer(&timer);
	timer.function = lcs_lancmd_timeout;
	timer.data = (unsigned long) reply;
	timer.expires = jiffies + HZ*card->lancmd_timeout;
	add_timer(&timer);
	wait_event(reply->wait_q, reply->received);
	del_timer_sync(&timer);
	LCS_DBF_TEXT_(4, trace, "rc:%d",reply->rc);
	rc = reply->rc;
	lcs_put_reply(reply);
	return rc ? -EIO : 0;
}

/**
 * LCS startup command
 */
static int
lcs_send_startup(struct lcs_card *card, __u8 initiator)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2, trace, "startup");
	buffer = lcs_get_lancmd(card, LCS_STD_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_STARTUP;
	cmd->initiator = initiator;
	cmd->cmd.lcs_startup.buff_size = LCS_IOBUFFERSIZE;
	return lcs_send_lancmd(card, buffer, NULL);
}

/**
 * LCS shutdown command
 */
static int
lcs_send_shutdown(struct lcs_card *card)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2, trace, "shutdown");
	buffer = lcs_get_lancmd(card, LCS_STD_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_SHUTDOWN;
	cmd->initiator = LCS_INITIATOR_TCPIP;
	return lcs_send_lancmd(card, buffer, NULL);
}

/**
 * LCS lanstat command
 */
static void
__lcs_lanstat_cb(struct lcs_card *card, struct lcs_cmd *cmd)
{
	LCS_DBF_TEXT(2, trace, "statcb");
	memcpy(card->mac, cmd->cmd.lcs_lanstat_cmd.mac_addr, LCS_MAC_LENGTH);
}

static int
lcs_send_lanstat(struct lcs_card *card)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2,trace, "cmdstat");
	buffer = lcs_get_lancmd(card, LCS_STD_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	/* Setup lanstat command. */
	cmd->cmd_code = LCS_CMD_LANSTAT;
	cmd->initiator = LCS_INITIATOR_TCPIP;
	cmd->cmd.lcs_std_cmd.lan_type = card->lan_type;
	cmd->cmd.lcs_std_cmd.portno = card->portno;
	return lcs_send_lancmd(card, buffer, __lcs_lanstat_cb);
}

/**
 * send stoplan command
 */
static int
lcs_send_stoplan(struct lcs_card *card, __u8 initiator)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2, trace, "cmdstpln");
	buffer = lcs_get_lancmd(card, LCS_STD_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_STOPLAN;
	cmd->initiator = initiator;
	cmd->cmd.lcs_std_cmd.lan_type = card->lan_type;
	cmd->cmd.lcs_std_cmd.portno = card->portno;
	return lcs_send_lancmd(card, buffer, NULL);
}

/**
 * send startlan command
 */
static void
__lcs_send_startlan_cb(struct lcs_card *card, struct lcs_cmd *cmd)
{
	LCS_DBF_TEXT(2, trace, "srtlancb");
	card->lan_type = cmd->cmd.lcs_std_cmd.lan_type;
	card->portno = cmd->cmd.lcs_std_cmd.portno;
}

static int
lcs_send_startlan(struct lcs_card *card, __u8 initiator)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2, trace, "cmdstaln");
	buffer = lcs_get_lancmd(card, LCS_STD_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_STARTLAN;
	cmd->initiator = initiator;
	cmd->cmd.lcs_std_cmd.lan_type = card->lan_type;
	cmd->cmd.lcs_std_cmd.portno = card->portno;
	return lcs_send_lancmd(card, buffer, __lcs_send_startlan_cb);
}

#ifdef CONFIG_IP_MULTICAST
/**
 * send setipm command (Multicast)
 */
static int
lcs_send_setipm(struct lcs_card *card,struct lcs_ipm_list *ipm_list)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2, trace, "cmdsetim");
	buffer = lcs_get_lancmd(card, LCS_MULTICAST_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_SETIPM;
	cmd->initiator = LCS_INITIATOR_TCPIP;
	cmd->cmd.lcs_qipassist.lan_type = card->lan_type;
	cmd->cmd.lcs_qipassist.portno = card->portno;
	cmd->cmd.lcs_qipassist.version = 4;
	cmd->cmd.lcs_qipassist.num_ip_pairs = 1;
	memcpy(cmd->cmd.lcs_qipassist.lcs_ipass_ctlmsg.ip_mac_pair,
	       &ipm_list->ipm, sizeof (struct lcs_ip_mac_pair));
	LCS_DBF_TEXT_(2, trace, "%x",ipm_list->ipm.ip_addr);
	return lcs_send_lancmd(card, buffer, NULL);
}

/**
 * send delipm command (Multicast)
 */
static int
lcs_send_delipm(struct lcs_card *card,struct lcs_ipm_list *ipm_list)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;

	LCS_DBF_TEXT(2, trace, "cmddelim");
	buffer = lcs_get_lancmd(card, LCS_MULTICAST_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_DELIPM;
	cmd->initiator = LCS_INITIATOR_TCPIP;
	cmd->cmd.lcs_qipassist.lan_type = card->lan_type;
	cmd->cmd.lcs_qipassist.portno = card->portno;
	cmd->cmd.lcs_qipassist.version = 4;
	cmd->cmd.lcs_qipassist.num_ip_pairs = 1;
	memcpy(cmd->cmd.lcs_qipassist.lcs_ipass_ctlmsg.ip_mac_pair,
	       &ipm_list->ipm, sizeof (struct lcs_ip_mac_pair));
	LCS_DBF_TEXT_(2, trace, "%x",ipm_list->ipm.ip_addr);
	return lcs_send_lancmd(card, buffer, NULL);
}

/**
 * check if multicast is supported by LCS
 */
static void
__lcs_check_multicast_cb(struct lcs_card *card, struct lcs_cmd *cmd)
{
	LCS_DBF_TEXT(2, trace, "chkmccb");
	card->ip_assists_supported =
		cmd->cmd.lcs_qipassist.ip_assists_supported;
	card->ip_assists_enabled =
		cmd->cmd.lcs_qipassist.ip_assists_enabled;
}

static int
lcs_check_multicast_support(struct lcs_card *card)
{
	struct lcs_buffer *buffer;
	struct lcs_cmd *cmd;
	int rc;

	LCS_DBF_TEXT(2, trace, "cmdqipa");
	/* Send query ipassist. */
	buffer = lcs_get_lancmd(card, LCS_STD_CMD_SIZE);
	cmd = (struct lcs_cmd *) buffer->data;
	cmd->cmd_code = LCS_CMD_QIPASSIST;
	cmd->initiator = LCS_INITIATOR_TCPIP;
	cmd->cmd.lcs_qipassist.lan_type = card->lan_type;
	cmd->cmd.lcs_qipassist.portno = card->portno;
	cmd->cmd.lcs_qipassist.version = 4;
	cmd->cmd.lcs_qipassist.num_ip_pairs = 1;
	rc = lcs_send_lancmd(card, buffer, __lcs_check_multicast_cb);
	if (rc != 0) {
		PRINT_ERR("Query IPAssist failed. Assuming unsupported!\n");
		return -EOPNOTSUPP;
	}
	if (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT)
		return 0;
	return -EOPNOTSUPP;
}

/**
 * set or del multicast address on LCS card
 */
static void
lcs_fix_multicast_list(struct lcs_card *card)
{
	struct list_head failed_list;
	struct lcs_ipm_list *ipm, *tmp;
	unsigned long flags;
	int rc;

	LCS_DBF_TEXT(4,trace, "fixipm");
	INIT_LIST_HEAD(&failed_list);
	spin_lock_irqsave(&card->ipm_lock, flags);
list_modified:
	list_for_each_entry_safe(ipm, tmp, &card->ipm_list, list){
		switch (ipm->ipm_state) {
		case LCS_IPM_STATE_SET_REQUIRED:
			/* del from ipm_list so noone else can tamper with
			 * this entry */
			list_del_init(&ipm->list);
			spin_unlock_irqrestore(&card->ipm_lock, flags);
			rc = lcs_send_setipm(card, ipm);
			spin_lock_irqsave(&card->ipm_lock, flags);
			if (rc) {
				PRINT_INFO("Adding multicast address failed."
					   "Table possibly full!\n");
				/* store ipm in failed list -> will be added
				 * to ipm_list again, so a retry will be done
				 * during the next call of this function */
				list_add_tail(&ipm->list, &failed_list);
			} else {
				ipm->ipm_state = LCS_IPM_STATE_ON_CARD;
				/* re-insert into ipm_list */
				list_add_tail(&ipm->list, &card->ipm_list);
			}
			goto list_modified;
		case LCS_IPM_STATE_DEL_REQUIRED:
			list_del(&ipm->list);
			spin_unlock_irqrestore(&card->ipm_lock, flags);
			lcs_send_delipm(card, ipm);
			spin_lock_irqsave(&card->ipm_lock, flags);
			kfree(ipm);
			goto list_modified;
		case LCS_IPM_STATE_ON_CARD:
			break;
		}
	}
	/* re-insert all entries from the failed_list into ipm_list */
	list_for_each_entry_safe(ipm, tmp, &failed_list, list) {
		list_del_init(&ipm->list);
		list_add_tail(&ipm->list, &card->ipm_list);
	}
	spin_unlock_irqrestore(&card->ipm_lock, flags);
	if (card->state == DEV_STATE_UP)
		netif_wake_queue(card->dev);
}

/**
 * get mac address for the relevant Multicast address
 */
static void
lcs_get_mac_for_ipm(__u32 ipm, char *mac, struct net_device *dev)
{
	LCS_DBF_TEXT(4,trace, "getmac");
	if (dev->type == ARPHRD_IEEE802_TR)
		ip_tr_mc_map(ipm, mac);
	else
		ip_eth_mc_map(ipm, mac);
}