s390/qeth: Detect PNSO OC3 capability

This patch detects whether device-to-bridge-notification, provided
by the Perform Network Subchannel Operation (PNSO) operation code
ADDR_INFO (OC3), is supported by this card. A following patch will
map this to the learning_sync bridgeport flag, so we store it in
priv->brport_hw_features in bridgeport flag format.

Only IQD cards provide PNSO.
There is a feature bit to indicate whether the machine provides OC3,
unfortunately it is not set on old machines.
So PNSO is called to find out. As this will disable notification
and is exclusive with bridgeport_notification, this must be done
during card initialisation before previous settings are restored.

PNSO functionality requires some configuration values that are added to
the qeth_card.info structure. Some helper functions are defined to fill
them out when the card is brought online and some other places are
adapted, that can also benefit from these fields.

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

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 2ab130d5c42d..7cba3d0035bf 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -17,10 +17,12 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/etherdevice.h>
+#include <linux/if_bridge.h>
 #include <linux/list.h>
 #include <linux/hash.h>
 #include <linux/hashtable.h>
 #include <asm/chsc.h>
+#include <asm/css_chars.h>
 #include <asm/setup.h>
 #include "qeth_core.h"
 #include "qeth_l2.h"
@@ -826,6 +828,46 @@ static void qeth_l2_setup_bridgeport_attrs(struct qeth_card *card)
 	}
 }
 
+/**
+ *	qeth_l2_detect_dev2br_support() -
+ *	Detect whether this card supports 'dev to bridge fdb network address
+ *	change notification' and thus can support the learning_sync bridgeport
+ *	attribute
+ *	@card: qeth_card structure pointer
+ *
+ *	This is a destructive test and must be called before dev2br or
+ *	bridgeport address notification is enabled!
+ */
+static void qeth_l2_detect_dev2br_support(struct qeth_card *card)
+{
+	struct qeth_priv *priv = netdev_priv(card->dev);
+	bool dev2br_supported;
+	int rc;
+
+	QETH_CARD_TEXT(card, 2, "d2brsup");
+	if (!IS_IQD(card))
+		return;
+
+	/* dev2br requires valid cssid,iid,chid */
+	if (!card->info.ids_valid) {
+		dev2br_supported = false;
+	} else if (css_general_characteristics.enarf) {
+		dev2br_supported = true;
+	} else {
+		/* Old machines don't have the feature bit:
+		 * Probe by testing whether a disable succeeds
+		 */
+		rc = qeth_l2_pnso(card, PNSO_OC_NET_ADDR_INFO, 0, NULL, NULL);
+		dev2br_supported = !rc;
+	}
+	QETH_CARD_TEXT_(card, 2, "D2Bsup%02x", dev2br_supported);
+
+	if (dev2br_supported)
+		priv->brport_hw_features |= BR_LEARNING_SYNC;
+	else
+		priv->brport_hw_features &= ~BR_LEARNING_SYNC;
+}
+
 static int qeth_l2_set_online(struct qeth_card *card)
 {
 	struct ccwgroup_device *gdev = card->gdev;
@@ -840,6 +882,9 @@ static int qeth_l2_set_online(struct qeth_card *card)
 		goto out_remove;
 	}
 
+	/* query before bridgeport_notification may be enabled */
+	qeth_l2_detect_dev2br_support(card);
+
 	mutex_lock(&card->sbp_lock);
 	qeth_bridgeport_query_support(card);
 	if (card->options.sbp.supported_funcs) {