[RFC PATCH v3 net-next 10/11] Documentation: networking: add cpsw switchdev based driver documentation

From: Grygorii Strashko <grygorii.strashko@ti.com>
To: <netdev@vger.kernel.org>,
	Ilias Apalodimas <ilias.apalodimas@linaro.org>,
	Andrew Lunn <andrew@lunn.ch>,
	"David S . Miller" <davem@davemloft.net>,
	Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>,
	Jiri Pirko <jiri@resnulli.us>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
	Sekhar Nori <nsekhar@ti.com>, <linux-kernel@vger.kernel.org>,
	<linux-omap@vger.kernel.org>,
	Murali Karicheri <m-karicheri2@ti.com>,
	Ivan Vecera <ivecera@redhat.com>,
	Grygorii Strashko <grygorii.strashko@ti.com>
Subject: [RFC PATCH v3 net-next 10/11] Documentation: networking: add cpsw switchdev based driver documentation
Date: Thu, 25 Apr 2019 01:24:26 +0300	[thread overview]
Message-ID: <1556144667-27997-11-git-send-email-grygorii.strashko@ti.com> (raw)
In-Reply-To: <1556144667-27997-1-git-send-email-grygorii.strashko@ti.com>

From: Ilias Apalodimas <ilias.apalodimas@linaro.org>

A new cpsw dirver based on switchdev was added. Add documentation about
basic configuration and future features

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 .../device_drivers/ti/cpsw_switchdev.txt      | 159 ++++++++++++++++++
 1 file changed, 159 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/ti/cpsw_switchdev.txt

diff --git a/Documentation/networking/device_drivers/ti/cpsw_switchdev.txt b/Documentation/networking/device_drivers/ti/cpsw_switchdev.txt
new file mode 100644
index 000000000000..471e831365f0
--- /dev/null
+++ b/Documentation/networking/device_drivers/ti/cpsw_switchdev.txt
@@ -0,0 +1,159 @@
+* Texas Instruments CPSW switchdev based ethernet driver
+
+- Port renaming
+On older udev versions renaming of ethX to swXpY will not be automatically
+supported
+In order to rename via udev:
+ip -d link show dev sw0p1 | grep switchid
+
+SUBSYSTEM=="net", ACTION=="add", ATTR{phys_switch_id}==<switchid>, \
+        ATTR{phys_port_name}!="", NAME="sw0$attr{phys_port_name}"
+
+- The new (cpsw_new.c) driver is operating in dual-emac mode by default, thus
+working as 2 individual network interfaces. When the both interfaces joined
+the bridge - CPSW driver will enter a switch mode and discard dual_mac
+configuration. All configuration is implemented via switchdev API.
+
+CPSW will be switched back to dual_mac mode if any port leaves the bridge.
+ALE table is completely cleared and then refilled while switching between modes
+and introduces some limitation to bridge setup sequence.
+
+====================
+# Bridge setup
+====================
+ip link add name br0 type bridge
+ip link set dev br0 type bridge ageing_time 1000
+[*]ip link set dev br0 type bridge vlan_filtering 0
+[*]echo 0 > /sys/class/net/br0/bridge/default_vlan
+ip link set dev sw0p1 up
+ip link set dev sw0p2 up
+ip link set dev sw0p1 master br0
+ip link set dev sw0p2 master br0
+...
+[*]echo 1 > /sys/class/net/br0/bridge/default_vlan
+[*]ip link set dev br0 type bridge vlan_filtering 1
+
+
+=================
+# On/off STP
+=================
+ip link set dev BRDEV type bridge stp_state 1/0
+
+Note. Steps [*] are mandatory.
+
+====================
+# VLAN configuration
+====================
+bridge vlan add dev br0 vid 1 pvid untagged self <---- add cpu port to VLAN 1
+
+Note. This step is mandatory for bridge/default_vlan.
+
+=================
+# Add extra VLANs
+=================
+ 1. untagged:
+    bridge vlan add dev sw0p1 vid 100 pvid untagged master
+    bridge vlan add dev sw0p2 vid 100 pvid untagged master
+    bridge vlan add dev br0 vid 100 pvid untagged self <---- Add cpu port to VLAN100
+
+ 2. tagged:
+    bridge vlan add dev sw0p1 vid 100 master
+    bridge vlan add dev sw0p2 vid 100 master
+    bridge vlan add dev br0 vid 100 pvid tagged self <---- Add cpu port to VLAN100
+
+====
+FDBs
+====
+FDBs are automatically added on the appropriate switch port uppon detection
+
+Manually adding FDBs:
+bridge fdb add aa:bb:cc:dd:ee:ff dev sw0p1 master vlan 100
+bridge fdb add aa:bb:cc:dd:ee:fe dev sw0p2 master <---- Add on all VLANs
+
+====
+MDBs
+====
+MDBs are automatically added on the appropriate switch port uppon detection
+
+Manually adding MDBs:
+bridge mdb add dev br0 port sw0p1 grp 239.1.1.1 permanent vid 100
+bridge mdb add dev br0 port sw0p1 grp 239.1.1.1 permanent <---- Add on all VLANs
+
+==================
+MUlticast flooding
+==================
+CPU port mcast_flooding is always on
+
+Turning flooding on/off on swithch ports:
+bridge link set dev sw0p1 mcast_flood on/off
+
+==================
+Access and Trunk port
+==================
+ bridge vlan add dev sw0p1 vid 101 pvid untagged master
+ bridge vlan add dev sw0p2 vid 100 master
+
+
+ bridge vlan add dev br0 vid 100 self
+ ip link add link br0 name br0.100 type vlan id 100
+ - or -
+ [TBD] bridge vlan add dev br0 vid 100 untagged self
+
+ Note. Setting PVID on Bridge device itself working only for default VLAN,
+ but CPSW Host P0 port allows to configure it - need evaluation.
+
+=====================
+ NFS
+=====================
+The only way for NFS to work is by chrooting to a minimal environment when
+switch configuration that will affect connectivity is needed.
+Assuming you are booting NFS with eth1 interface(the script is hacky and
+it's just there to prove NFS is doable).
+
+setup.sh:
+#!/bin/sh
+mkdir proc
+mount -t proc none /proc
+ifconfig br0  > /dev/null
+if [ $? -ne 0 ]; then
+        echo "Setting up bridge"
+        ip link add name br0 type bridge
+        ip link set dev br0 type bridge ageing_time 1000
+        ip link set dev br0 type bridge vlan_filtering 1
+
+        ip link set eth1 down
+        ip link set eth1 name sw0p1
+        ip link set dev sw0p1 up
+        ip link set dev sw0p2 up
+        ip link set dev sw0p2 master br0
+        ip link set dev sw0p1 master br0
+        bridge vlan add dev br0 vid 1 pvid untagged self
+        ifconfig sw0p1 0.0.0.0
+        udhchc -i br0
+fi
+umount /proc
+
+run_nfs.sh:
+#!/bin/sh
+mkdir /tmp/root/bin -p
+mkdir /tmp/root/lib -p
+
+cp -r /lib/ /tmp/root/
+cp -r /bin/ /tmp/root/
+cp /sbin/ip /tmp/root/bin
+cp /sbin/bridge /tmp/root/bin
+cp /sbin/ifconfig /tmp/root/bin
+cp /sbin/udhcpc /tmp/root/bin
+cp /path/to/setup.sh /tmp/root/bin
+chroot /tmp/root/ busybox sh /bin/setup.sh
+
+run ./run_nfs.sh
+
+=====================
+Currently unsupported
+=====================
+1. ageing configuration
+2. Multicast flooding on/off for the CPU port
+3. Discovered FDBs/MDBs do not appear on 'bridge fdb/mdb show'
+4. VLANs offloading
+5. STP
\ No newline at end of file
-- 
2.17.1

