[PATCH AUTOSEL 4.19 134/146] IB/ipoib: Use dev_port to expose network interface port numbers

From: Sasha Levin
Date: Wed Oct 31 2018 - 19:42:36 EST

From: Arseny Maslennikov <ar@xxxxxxxxx>

[ Upstream commit 9b8b2a323008aedd39a8debb861b825707f01420 ]

Some InfiniBand network devices have multiple ports on the same PCI
function. This initializes the `dev_port' sysfs field of those
network interfaces with their port number.

Prior to this the kernel erroneously used the `dev_id' sysfs
field of those network interfaces to convey the port number to userspace.

The use of `dev_id' was considered correct until Linux 3.15,
when another field, `dev_port', was defined for this particular
purpose and `dev_id' was reserved for distinguishing stacked ifaces
(e.g: VLANs) with the same hardware address as their parent device.

Similar fixes to net/mlx4_en and many other drivers, which started
exporting this information through `dev_id' before 3.15, were accepted
into the kernel 4 years ago.
See 76a066f2a2a0 (`net/mlx4_en: Expose port number through sysfs').

Signed-off-by: Arseny Maslennikov <ar@xxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/infiniband/ulp/ipoib/ipoib_main.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index e3d28f9ad9c0..30f840f874b3 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1880,6 +1880,8 @@ static int ipoib_parent_init(struct net_device *ndev)
sizeof(union ib_gid));

SET_NETDEV_DEV(priv->dev, priv->ca->dev.parent);
+ priv->dev->dev_port = priv->port - 1;
+ /* Let's set this one too for backwards compatibility. */
priv->dev->dev_id = priv->port - 1;

return 0;