[3.13.y.z extended stable] Patch "ibmveth: Fix endian issues with rx_no_buffer statistic" has been added to staging queue

[Kamal Mostafa]

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

    ibmveth: Fix endian issues with rx_no_buffer statistic

to the linux-3.13.y-queue branch of the 3.13.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-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.8.

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

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 576fb3dfa8cb0684eede4afb4265f132bbd20832 Mon Sep 17 00:00:00 2001
From: Anton Blanchard <anton at samba.org>
Date: Fri, 22 Aug 2014 11:36:52 +1000
Subject: ibmveth: Fix endian issues with rx_no_buffer statistic

commit cbd5228199d8be45d895d9d0cc2b8ce53835fc21 upstream.

Hidden away in the last 8 bytes of the buffer_list page is a solitary
statistic. It needs to be byte swapped or else ethtool -S will
produce numbers that terrify the user.

Since we do this in multiple places, create a helper function with a
comment explaining what is going on.

Signed-off-by: Anton Blanchard <anton at samba.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/ethernet/ibm/ibmveth.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 6c0fd8e..895b086 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -293,6 +293,18 @@ failure:
 	atomic_add(buffers_added, &(pool->available));
 }

+/*
+ * The final 8 bytes of the buffer list is a counter of frames dropped
+ * because there was not a buffer in the buffer list capable of holding
+ * the frame.
+ */
+static void ibmveth_update_rx_no_buffer(struct ibmveth_adapter *adapter)
+{
+	__be64 *p = adapter->buffer_list_addr + 4096 - 8;
+
+	adapter->rx_no_buffer = be64_to_cpup(p);
+}
+
 /* replenish routine */
 static void ibmveth_replenish_task(struct ibmveth_adapter *adapter)
 {
@@ -308,8 +320,7 @@ static void ibmveth_replenish_task(struct ibmveth_adapter *adapter)
 			ibmveth_replenish_buffer_pool(adapter, pool);
 	}

-	adapter->rx_no_buffer = *(u64 *)(((char*)adapter->buffer_list_addr) +
-						4096 - 8);
+	ibmveth_update_rx_no_buffer(adapter);
 }

 /* empty and free ana buffer pool - also used to do cleanup in error paths */
@@ -699,8 +710,7 @@ static int ibmveth_close(struct net_device *netdev)

 	free_irq(netdev->irq, netdev);

-	adapter->rx_no_buffer = *(u64 *)(((char *)adapter->buffer_list_addr) +
-						4096 - 8);
+	ibmveth_update_rx_no_buffer(adapter);

 	ibmveth_cleanup(adapter);

--
1.9.1