s390/qeth: use node_descriptor struct

Rather than fumbling with hard-coded offsets, use the proper struct to
access the retrieved RCD information.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core.h

@@ -651,7 +651,7 @@ struct qeth_card_blkt {
 struct qeth_card_info {
 	unsigned short unit_addr2;
 	unsigned short cula;
-	unsigned short chpid;
+	u8 chpid;
 	__u16 func_level;
 	char mcl_level[QETH_MCL_LENGTH + 1];
 	u8 open_when_online:1;

drivers/s390/net/qeth_core_main.c

@@ -1775,19 +1775,32 @@ static int qeth_send_control_data(struct qeth_card *card,
 	return rc;
 }
 
+struct qeth_node_desc {
+	struct node_descriptor nd1;
+	struct node_descriptor nd2;
+	struct node_descriptor nd3;
+};
+
 static void qeth_read_conf_data_cb(struct qeth_card *card,
 				   struct qeth_cmd_buffer *iob)
 {
-	unsigned char *prcd = iob->data;
+	struct qeth_node_desc *nd = (struct qeth_node_desc *) iob->data;
+	u8 *tag;
 
 	QETH_CARD_TEXT(card, 2, "cfgunit");
-	card->info.chpid = prcd[30];
-	card->info.unit_addr2 = prcd[31];
-	card->info.cula = prcd[63];
-	card->info.is_vm_nic = ((prcd[0x10] == _ascebc['V']) &&
-				(prcd[0x11] == _ascebc['M']));
-	card->info.use_v1_blkt = prcd[74] == 0xF0 && prcd[75] == 0xF0 &&
-				 prcd[76] >= 0xF1 && prcd[76] <= 0xF4;
+	card->info.is_vm_nic = nd->nd1.plant[0] == _ascebc['V'] &&
+			       nd->nd1.plant[1] == _ascebc['M'];
+	tag = (u8 *)&nd->nd1.tag;
+	card->info.chpid = tag[0];
+	card->info.unit_addr2 = tag[1];
+
+	tag = (u8 *)&nd->nd2.tag;
+	card->info.cula = tag[1];
+
+	card->info.use_v1_blkt = nd->nd3.model[0] == 0xF0 &&
+				 nd->nd3.model[1] == 0xF0 &&
+				 nd->nd3.model[2] >= 0xF1 &&
+				 nd->nd3.model[2] <= 0xF4;
 
 	qeth_notify_reply(iob->reply, 0);
 	qeth_put_cmd(iob);
@@ -1803,6 +1816,8 @@ static int qeth_read_conf_data(struct qeth_card *card)
 	ciw = ccw_device_get_ciw(channel->ccwdev, CIW_TYPE_RCD);
 	if (!ciw || ciw->cmd == 0)
 		return -EOPNOTSUPP;
+	if (ciw->count < sizeof(struct qeth_node_desc))
+		return -EINVAL;
 
 	iob = qeth_alloc_cmd(channel, ciw->count, 1, QETH_RCD_TIMEOUT);
 	if (!iob)