[ 3.5.y.z extended stable ] Patch "net/eth/ibmveth: Fixup retrieval of MAC address" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    net/eth/ibmveth: Fixup retrieval of MAC address

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 686ea64c7d68fdf741378769ad0dfddfdb36af91 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Date: Fri, 3 May 2013 17:19:01 +0000
Subject: [PATCH] net/eth/ibmveth: Fixup retrieval of MAC address

commit 13f85203e1060da83d9ec1c1c5a63343eaab8de4 upstream.

Some ancient pHyp versions used to create a 8 bytes local-mac-address
property in the device-tree instead of a 6 bytes one for veth.

The Linux driver code to deal with that is an insane hack which also
happens to break with some choices of MAC addresses in qemu by testing
for a bit in the address rather than just looking at the size of the
property.

Sanitize this by doing the latter instead.

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/ibm/ibmveth.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index b68d28a..33a1760 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1327,7 +1327,7 @@ static const struct net_device_ops ibmveth_netdev_ops = {
 static int __devinit ibmveth_probe(struct vio_dev *dev,
 				   const struct vio_device_id *id)
 {
-	int rc, i;
+	int rc, i, mac_len;
 	struct net_device *netdev;
 	struct ibmveth_adapter *adapter;
 	unsigned char *mac_addr_p;
@@ -1337,11 +1337,19 @@ static int __devinit ibmveth_probe(struct vio_dev *dev,
 		dev->unit_address);

 	mac_addr_p = (unsigned char *)vio_get_attribute(dev, VETH_MAC_ADDR,
-							NULL);
+							&mac_len);
 	if (!mac_addr_p) {
 		dev_err(&dev->dev, "Can't find VETH_MAC_ADDR attribute\n");
 		return -EINVAL;
 	}
+	/* Workaround for old/broken pHyp */
+	if (mac_len == 8)
+		mac_addr_p += 2;
+	else if (mac_len != 6) {
+		dev_err(&dev->dev, "VETH_MAC_ADDR attribute wrong len %d\n",
+			mac_len);
+		return -EINVAL;
+	}

 	mcastFilterSize_p = (unsigned int *)vio_get_attribute(dev,
 						VETH_MCAST_FILTER_SIZE, NULL);
@@ -1366,17 +1374,6 @@ static int __devinit ibmveth_probe(struct vio_dev *dev,

 	netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);

-	/*
-	 * Some older boxes running PHYP non-natively have an OF that returns
-	 * a 8-byte local-mac-address field (and the first 2 bytes have to be
-	 * ignored) while newer boxes' OF return a 6-byte field. Note that
-	 * IEEE 1275 specifies that local-mac-address must be a 6-byte field.
-	 * The RPA doc specifies that the first byte must be 10b, so we'll
-	 * just look for it to solve this 8 vs. 6 byte field issue
-	 */
-	if ((*mac_addr_p & 0x3) != 0x02)
-		mac_addr_p += 2;
-
 	adapter->mac_addr = 0;
 	memcpy(&adapter->mac_addr, mac_addr_p, 6);

--
1.8.1.2