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package/qca/nss-ifb/README.md

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+NSS Physical Interface Ingress Driver
+=====================================
+
+This driver redirect NSS physical interface (namely GMACs) ingress traffic to itself
+and sends it back to the Linux network stack (as the source GMACs packets) as it's
+egress traffic.
+
+This allows the NSS QDISC drivers to manage the egress traffic of this driver's
+NSS virtual interface.
+
+This driver will create a single network interface named 'nssifb'.  The default
+source interface is defined as 'eth0'.  It can be changed using the following module
+parameter path:
+
+/sys/module/nss-ifb/parameter/nss_src_dev
+
+To change the source NSS physical interface to 'eth1', use the following command:
+
+printf eth1 > /sys/module/nss-ifb/parameter/nss_src_dev
+
+You need to change the source interface first before bringing up the 'nssifb'
+interface.  Changing it after the interface is up will have no effect.  You need
+to bring down the interface and bring it back up to have the changes take effect.
+
+CPU load imposed on the Krait CPUs appears negligible with this driver intercepting
+the physical interface's ingress traffic.  Full line speed of the GMAC interface
+could still be achieved.
+
+The commands below shows an example to shape ingress traffic to 500 Mbps and egress
+to 200 Mbps for the 'eth0' interface.
+
+# Load the module if it's not loaded
+modprobe nss-ifb
+
+# Bring up the nssifb interface to active ingress redirect
+ip link set up nssifb
+
+# Shape ingress traffic to 500 Mbit with chained NSSFQ_CODEL
+tc qdisc add dev nssifb root handle 1: nsstbl rate 500Mbit burst 1Mb
+tc qdisc add dev nssifb parent 1: handle 10: nssfq_codel limit 10240 flows 1024 quantum 1514 target 5ms interval 100ms set_default
+
+# Shape egress traffic to 200 Mbit with chained NSSFQ_CODEL
+tc qdisc add dev eth0 root handle 1: nsstbl rate 200Mbit burst 1Mb
+tc qdisc add dev eth0 parent 1: handle 10: nssfq_codel limit 10240 flows 1024 quantum 1514 target 5ms interval 100ms set_default
+