s390/qeth: remove qeth_wait_for_buffer()

The basic MPC initialization sequence is strictly sequential, and
waiting for an available cmd buffer should never be necessary.
So this change only affects the OSN path, where dangling waiters on an
unbounded wait_event() are not desirable. Switch to qeth_get_buffers(),
and let OSN callers deal with -ENOMEM.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 32 insertions, 26 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 0403a1405872..3d25cff404fe 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -65,7 +65,6 @@ static struct lock_class_key qdio_out_skb_queue_key;
 static void qeth_issue_next_read_cb(struct qeth_card *card,
 				    struct qeth_channel *channel,
 				    struct qeth_cmd_buffer *iob);
-static struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *);
 static void qeth_free_buffer_pool(struct qeth_card *);
 static int qeth_qdio_establish(struct qeth_card *);
 static void qeth_free_qdio_queues(struct qeth_card *card);
@@ -746,7 +745,7 @@ static void qeth_cancel_cmd(struct qeth_cmd_buffer *iob, int rc)
 	qeth_release_buffer(iob->channel, iob);
 }
 
-static struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel)
+struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel)
 {
 	struct qeth_cmd_buffer *buffer = NULL;
 	unsigned long flags;
@@ -756,15 +755,7 @@ static struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel)
 	spin_unlock_irqrestore(&channel->iob_lock, flags);
 	return buffer;
 }
-
-struct qeth_cmd_buffer *qeth_wait_for_buffer(struct qeth_channel *channel)
-{
-	struct qeth_cmd_buffer *buffer;
-	wait_event(channel->wait_q,
-		   ((buffer = qeth_get_buffer(channel)) != NULL));
-	return buffer;
-}
-EXPORT_SYMBOL_GPL(qeth_wait_for_buffer);
+EXPORT_SYMBOL_GPL(qeth_get_buffer);
 
 void qeth_clear_cmd_buffers(struct qeth_channel *channel)
 {
@@ -1794,6 +1785,16 @@ static void qeth_mpc_finalize_cmd(struct qeth_card *card,
 	iob->callback = qeth_release_buffer_cb;
 }
 
+static struct qeth_cmd_buffer *qeth_mpc_get_cmd_buffer(struct qeth_card *card)
+{
+	struct qeth_cmd_buffer *iob;
+
+	iob = qeth_get_buffer(&card->write);
+	if (iob)
+		iob->finalize = qeth_mpc_finalize_cmd;
+	return iob;
+}
+
 /**
  * qeth_send_control_data() -	send control command to the card
  * @card:			qeth_card structure pointer
@@ -2102,10 +2103,11 @@ static int qeth_cm_enable(struct qeth_card *card)
 
 	QETH_DBF_TEXT(SETUP, 2, "cmenable");
 
-	iob = qeth_wait_for_buffer(&card->write);
-	iob->finalize = qeth_mpc_finalize_cmd;
-	memcpy(iob->data, CM_ENABLE, CM_ENABLE_SIZE);
+	iob = qeth_mpc_get_cmd_buffer(card);
+	if (!iob)
+		return -ENOMEM;
 
+	memcpy(iob->data, CM_ENABLE, CM_ENABLE_SIZE);
 	memcpy(QETH_CM_ENABLE_ISSUER_RM_TOKEN(iob->data),
 	       &card->token.issuer_rm_r, QETH_MPC_TOKEN_LENGTH);
 	memcpy(QETH_CM_ENABLE_FILTER_TOKEN(iob->data),
@@ -2137,10 +2139,11 @@ static int qeth_cm_setup(struct qeth_card *card)
 
 	QETH_DBF_TEXT(SETUP, 2, "cmsetup");
 
-	iob = qeth_wait_for_buffer(&card->write);
-	iob->finalize = qeth_mpc_finalize_cmd;
-	memcpy(iob->data, CM_SETUP, CM_SETUP_SIZE);
+	iob = qeth_mpc_get_cmd_buffer(card);
+	if (!iob)
+		return -ENOMEM;
 
+	memcpy(iob->data, CM_SETUP, CM_SETUP_SIZE);
 	memcpy(QETH_CM_SETUP_DEST_ADDR(iob->data),
 	       &card->token.issuer_rm_r, QETH_MPC_TOKEN_LENGTH);
 	memcpy(QETH_CM_SETUP_CONNECTION_TOKEN(iob->data),
@@ -2256,10 +2259,11 @@ static int qeth_ulp_enable(struct qeth_card *card)
 	/*FIXME: trace view callbacks*/
 	QETH_DBF_TEXT(SETUP, 2, "ulpenabl");
 
-	iob = qeth_wait_for_buffer(&card->write);
-	iob->finalize = qeth_mpc_finalize_cmd;
-	memcpy(iob->data, ULP_ENABLE, ULP_ENABLE_SIZE);
+	iob = qeth_mpc_get_cmd_buffer(card);
+	if (!iob)
+		return -ENOMEM;
 
+	memcpy(iob->data, ULP_ENABLE, ULP_ENABLE_SIZE);
 	*(QETH_ULP_ENABLE_LINKNUM(iob->data)) = (u8) card->dev->dev_port;
 	memcpy(QETH_ULP_ENABLE_PROT_TYPE(iob->data), &prot_type, 1);
 	memcpy(QETH_ULP_ENABLE_DEST_ADDR(iob->data),
@@ -2303,10 +2307,11 @@ static int qeth_ulp_setup(struct qeth_card *card)
 
 	QETH_DBF_TEXT(SETUP, 2, "ulpsetup");
 
-	iob = qeth_wait_for_buffer(&card->write);
-	iob->finalize = qeth_mpc_finalize_cmd;
-	memcpy(iob->data, ULP_SETUP, ULP_SETUP_SIZE);
+	iob = qeth_mpc_get_cmd_buffer(card);
+	if (!iob)
+		return -ENOMEM;
 
+	memcpy(iob->data, ULP_SETUP, ULP_SETUP_SIZE);
 	memcpy(QETH_ULP_SETUP_DEST_ADDR(iob->data),
 	       &card->token.cm_connection_r, QETH_MPC_TOKEN_LENGTH);
 	memcpy(QETH_ULP_SETUP_CONNECTION_TOKEN(iob->data),
@@ -2492,10 +2497,11 @@ static int qeth_dm_act(struct qeth_card *card)
 
 	QETH_DBF_TEXT(SETUP, 2, "dmact");
 
-	iob = qeth_wait_for_buffer(&card->write);
-	iob->finalize = qeth_mpc_finalize_cmd;
-	memcpy(iob->data, DM_ACT, DM_ACT_SIZE);
+	iob = qeth_mpc_get_cmd_buffer(card);
+	if (!iob)
+		return -ENOMEM;
 
+	memcpy(iob->data, DM_ACT, DM_ACT_SIZE);
 	memcpy(QETH_DM_ACT_DEST_ADDR(iob->data),
 	       &card->token.cm_connection_r, QETH_MPC_TOKEN_LENGTH);
 	memcpy(QETH_DM_ACT_CONNECTION_TOKEN(iob->data),