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Commit 0951c6ba authored by Julian Wiedmann's avatar Julian Wiedmann Committed by David S. Miller
Browse files

s390/qeth: simplify reply object handling 



Current code enqueues & dequeues a reply object from the waiter list
in various places. In particular, the dequeue & enqueue in
qeth_send_control_data_cb() looks fragile - this can cause
qeth_clear_ipacmd_list() to skip the active object.
Add some helpers, and boil the logic down by giving
qeth_send_control_data() the sole responsibility to add and remove
objects.

qeth_send_control_data_cb() and qeth_clear_ipacmd_list() will now only
notify the reply object to interrupt its wait cycle. This can cause
a slight delay in the removal, but that's no concern.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 51581fd0

drivers/s390/net/qeth_core_main.c

+61 −57
Original line number Diff line number Diff line
@@ -566,6 +566,7 @@ static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card) 
	if (reply) {

		refcount_set(&reply->refcnt, 1);

		atomic_set(&reply->received, 0);

		init_waitqueue_head(&reply->wait_q);

	}

	return reply;

}
@@ -581,6 +582,26 @@ static void qeth_put_reply(struct qeth_reply *reply) 
		kfree(reply);

}



static void qeth_enqueue_reply(struct qeth_card *card, struct qeth_reply *reply)

{

	spin_lock_irq(&card->lock);

	list_add_tail(&reply->list, &card->cmd_waiter_list);

	spin_unlock_irq(&card->lock);

}



static void qeth_dequeue_reply(struct qeth_card *card, struct qeth_reply *reply)

{

	spin_lock_irq(&card->lock);

	list_del(&reply->list);

	spin_unlock_irq(&card->lock);

}



static void qeth_notify_reply(struct qeth_reply *reply)

{

	atomic_inc(&reply->received);

	wake_up(&reply->wait_q);

}



static void qeth_issue_ipa_msg(struct qeth_ipa_cmd *cmd, int rc,

		struct qeth_card *card)

{
@@ -657,19 +678,15 @@ static struct qeth_ipa_cmd *qeth_check_ipa_data(struct qeth_card *card, 


void qeth_clear_ipacmd_list(struct qeth_card *card)

{

	struct qeth_reply *reply, *r;

	struct qeth_reply *reply;

	unsigned long flags;



	QETH_CARD_TEXT(card, 4, "clipalst");



	spin_lock_irqsave(&card->lock, flags);

	list_for_each_entry_safe(reply, r, &card->cmd_waiter_list, list) {

		qeth_get_reply(reply);

	list_for_each_entry(reply, &card->cmd_waiter_list, list) {

		reply->rc = -EIO;

		atomic_inc(&reply->received);

		list_del_init(&reply->list);

		wake_up(&reply->wait_q);

		qeth_put_reply(reply);

		qeth_notify_reply(reply);

	}

	spin_unlock_irqrestore(&card->lock, flags);

}
@@ -774,9 +791,10 @@ static void qeth_send_control_data_cb(struct qeth_card *card, 
				      struct qeth_cmd_buffer *iob)

{

	struct qeth_ipa_cmd *cmd = NULL;

	struct qeth_reply *reply, *r;

	struct qeth_reply *reply = NULL;

	struct qeth_reply *r;

	unsigned long flags;

	int keep_reply;

	int keep_reply = 0;

	int rc = 0;



	QETH_CARD_TEXT(card, 4, "sndctlcb");
@@ -808,44 +826,40 @@ static void qeth_send_control_data_cb(struct qeth_card *card, 
			goto out;

	}



	/* match against pending cmd requests */

	spin_lock_irqsave(&card->lock, flags);

	list_for_each_entry_safe(reply, r, &card->cmd_waiter_list, list) {

		if ((reply->seqno == QETH_IDX_COMMAND_SEQNO) ||

		    ((cmd) && (reply->seqno == cmd->hdr.seqno))) {

	list_for_each_entry(r, &card->cmd_waiter_list, list) {

		if ((r->seqno == QETH_IDX_COMMAND_SEQNO) ||

		    (cmd && (r->seqno == cmd->hdr.seqno))) {

			reply = r;

			/* take the object outside the lock */

			qeth_get_reply(reply);

			list_del_init(&reply->list);

			break;

		}

	}

	spin_unlock_irqrestore(&card->lock, flags);

			keep_reply = 0;

			if (reply->callback != NULL) {



	if (!reply)

		goto out;



	if (reply->callback) {

		if (cmd) {

					reply->offset = (__u16)((char *)cmd -

							(char *)iob->data);

					keep_reply = reply->callback(card,

							reply,

			reply->offset = (u16)((char *)cmd - (char *)iob->data);

			keep_reply = reply->callback(card, reply,

						     (unsigned long)cmd);

		} else

					keep_reply = reply->callback(card,

							reply,

			keep_reply = reply->callback(card, reply,

						     (unsigned long)iob);

	}

	if (cmd)

		reply->rc = (u16) cmd->hdr.return_code;

	else if (iob->rc)

		reply->rc = iob->rc;

			if (keep_reply) {

				spin_lock_irqsave(&card->lock, flags);

				list_add_tail(&reply->list,

					      &card->cmd_waiter_list);

				spin_unlock_irqrestore(&card->lock, flags);

			} else {

				atomic_inc(&reply->received);

				wake_up(&reply->wait_q);

			}



	if (!keep_reply)

		qeth_notify_reply(reply);

	qeth_put_reply(reply);

			goto out;

		}

	}

	spin_unlock_irqrestore(&card->lock, flags);



out:

	memcpy(&card->seqno.pdu_hdr_ack,

		QETH_PDU_HEADER_SEQ_NO(iob->data),
@@ -2047,8 +2061,6 @@ static int qeth_send_control_data(struct qeth_card *card, int len, 
	reply->callback = reply_cb;

	reply->param = reply_param;



	init_waitqueue_head(&reply->wait_q);



	while (atomic_cmpxchg(&channel->irq_pending, 0, 1)) ;



	if (IS_IPA(iob->data)) {
@@ -2062,9 +2074,7 @@ static int qeth_send_control_data(struct qeth_card *card, int len, 
	}

	qeth_prepare_control_data(card, len, iob);



	spin_lock_irq(&card->lock);

	list_add_tail(&reply->list, &card->cmd_waiter_list);

	spin_unlock_irq(&card->lock);

	qeth_enqueue_reply(card, reply);



	timeout = jiffies + event_timeout;
@@ -2077,10 +2087,8 @@ static int qeth_send_control_data(struct qeth_card *card, int len, 
		QETH_DBF_MESSAGE(2, "qeth_send_control_data on device %x: ccw_device_start rc = %i\n",

				 CARD_DEVID(card), rc);

		QETH_CARD_TEXT_(card, 2, " err%d", rc);

		spin_lock_irq(&card->lock);

		list_del_init(&reply->list);

		qeth_dequeue_reply(card, reply);

		qeth_put_reply(reply);

		spin_unlock_irq(&card->lock);

		qeth_release_buffer(channel, iob);

		atomic_set(&channel->irq_pending, 0);

		wake_up(&card->wait_q);
@@ -2102,19 +2110,15 @@ static int qeth_send_control_data(struct qeth_card *card, int len, 
		}

	}



	qeth_dequeue_reply(card, reply);

	rc = reply->rc;

	qeth_put_reply(reply);

	return rc;



time_err:

	reply->rc = -ETIME;

	spin_lock_irq(&card->lock);

	list_del_init(&reply->list);

	spin_unlock_irq(&card->lock);

	atomic_inc(&reply->received);

	rc = reply->rc;

	qeth_dequeue_reply(card, reply);

	qeth_put_reply(reply);

	return rc;

	return -ETIME;

}



static int qeth_cm_enable_cb(struct qeth_card *card, struct qeth_reply *reply,