qeth: bridgeport support - basic control

Introduce functions to assign roles and check state of bridgeport-capable
HiperSocket devices, and sysfs attributes providing access to these
functions from userspace. Introduce udev events emitted when the state
of a bridgeport device changes.

Signed-off-by: Eugene Crosser <eugene.crosser@ru.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 0 deletions

diff --git a/Documentation/s390/qeth.txt b/Documentation/s390/qeth.txt
new file mode 100644
index 000000000000..c08c305efd4d
--- /dev/null
+++ b/Documentation/s390/qeth.txt
@@ -0,0 +1,21 @@
+IBM s390 QDIO Ethernet Driver
+
+HiperSockets Bridge Port Support
+
+Uevents
+
+To generate the events the device must be assigned a role of either
+a primary or a secondary Bridge Port. For more information, see
+"z/VM Connectivity, SC24-6174".
+
+When run on HiperSockets Bridge Capable Port hardware, and the state
+of some configured Bridge Port device on the channel changes, a udev
+event with ACTION=CHANGE is emitted on behalf of the corresponding
+ccwgroup device. The event has the following attributes:
+
+BRIDGEPORT=statechange -  indicates that the Bridge Port device changed
+  its state.
+
+ROLE={primary|secondary|none} - the role assigned to the port.
+
+STATE={active|standby|inactive} - the newly assumed state of the port.