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From:   Hariprasad Kelam <hkelam@marvell.com>
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Subject: [net-next Patch v6 6/6] docs: octeontx2: Add Documentation for QOS
Date:   Thu, 6 Apr 2023 15:51:03 +0530
Message-ID: <20230406102103.19910-7-hkelam@marvell.com>
In-Reply-To: <20230406102103.19910-1-hkelam@marvell.com>
References: <20230406102103.19910-1-hkelam@marvell.com>
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Add QOS example configuration along with tc-htb commands

Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
---
 .../ethernet/marvell/octeontx2.rst            | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/Documentation/networking/device_drivers/ethernet/marvell/octeontx2.rst b/Documentation/networking/device_drivers/ethernet/marvell/octeontx2.rst
index 5ba9015336e2..eca4309964c8 100644
--- a/Documentation/networking/device_drivers/ethernet/marvell/octeontx2.rst
+++ b/Documentation/networking/device_drivers/ethernet/marvell/octeontx2.rst
@@ -13,6 +13,7 @@ Contents
 - `Drivers`_
 - `Basic packet flow`_
 - `Devlink health reporters`_
+- `Quality of service`_
 
 Overview
 ========
@@ -287,3 +288,41 @@ For example::
 	 NIX_AF_ERR:
 	        NIX Error Interrupt Reg : 64
 	        Rx on unmapped PF_FUNC
+
+
+Quality of service
+==================
+
+octeontx2 silicon and CN10K transmit interface consists of five transmit levels starting from SMQ/MDQ, TL4 to TL1.
+The hardware uses the below algorithms depending on the priority of scheduler queues
+
+1. Strict Priority
+
+      -  Once packets are submitted to MDQ, hardware picks all active MDQs having different priority
+         using strict priority.
+
+2. Round Robin
+
+      - Active MDQs having the same priority level are chosen using round robin.
+
+3. Each packet will traverse MDQ, TL4 to TL1 levels. Each level contains an array of queues to support scheduling and
+   shaping.
+
+4. once the user creates tc classes with different priority
+
+   -  Driver configures schedulers allocated to the class with specified priority along with rate-limiting configuration.
+
+5. Enable HW TC offload on the interface::
+
+        # ethtool -K <interface> hw-tc-offload on
+
+6. Crate htb root::
+
+        # tc qdisc add dev <interface> clsact
+        # tc qdisc replace dev <interface> root handle 1: htb offload
+
+7. Create tc classes with different  priorities::
+
+        # tc class add dev <interface> parent 1: classid 1:1 htb rate 10Gbit prio 1
+
+        # tc class add dev <interface> parent 1: classid 1:2 htb rate 10Gbit prio 7
-- 
2.17.1