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Message-ID: <a205c24f-f170-47eb-a21e-1809290fa7b2@kernel.org>
Date: Mon, 18 Dec 2023 19:20:33 +0200
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Subject: Re: [PATCH net-next v10 08/10] net: ethernet: ti: am65-cpsw: add
 mqprio qdisc offload in channel mode
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To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
 pabeni@redhat.com, shuah@kernel.org, vladimir.oltean@nxp.com
Cc: s-vadapalli@ti.com, r-gunasekaran@ti.com, vigneshr@ti.com, srk@ti.com,
 horms@kernel.org, p-varis@ti.com, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org
References: <20231218125513.52337-1-rogerq@kernel.org>
 <20231218125513.52337-9-rogerq@kernel.org>
From: Roger Quadros <rogerq@kernel.org>
In-Reply-To: <20231218125513.52337-9-rogerq@kernel.org>
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On 18/12/2023 14:55, Roger Quadros wrote:
> From: Grygorii Strashko <grygorii.strashko@ti.com>
> 
> This patch adds MQPRIO Qdisc offload in full 'channel' mode which allows
> not only setting up pri:tc mapping, but also configuring TX shapers
> (rate-limiting) on external port FIFOs.
> 
> The MQPRIO Qdisc offload is expected to work with or without VLAN/priority
> tagged packets.
> 
> The CPSW external Port FIFO has 8 Priority queues. The rate-limit can be
> set for each of these priority queues. Which Priority queue a packet is
> assigned to depends on PN_REG_TX_PRI_MAP register which maps header
> priority to switch priority.
> 
> The header priority of a packet is assigned via the RX_PRI_MAP_REG which
> maps packet priority to header priority.
> 
> The packet priority is either the VLAN priority (for VLAN tagged packets)
> or the thread/channel offset.
> 
> For simplicity, we assign the same priority queue to all queues of a
> Traffic Class so it can be rate-limited correctly.
> 
> Configuration example:
>  ethtool -L eth1 tx 5
>  ethtool --set-priv-flags eth1 p0-rx-ptype-rrobin off
> 
>  tc qdisc add dev eth1 parent root handle 100: mqprio num_tc 3 \
>  map 0 0 1 2 0 0 0 0 0 0 0 0 0 0 0 0 \
>  queues 1@0 1@1 1@2 hw 1 mode channel \
>  shaper bw_rlimit min_rate 0 100mbit 200mbit max_rate 0 101mbit 202mbit
> 
>  tc qdisc replace dev eth2 handle 100: parent root mqprio num_tc 1 \
>  map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 queues 1@0 hw 1
> 
>  ip link add link eth1 name eth1.100 type vlan id 100
>  ip link set eth1.100 type vlan egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> 
> In the above example two ports share the same TX CPPI queue 0 for low
> priority traffic. 3 traffic classes are defined for eth1 and mapped to:
> TC0 - low priority, TX CPPI queue 0 -> ext Port 1 fifo0, no rate limit
> TC1 - prio 2, TX CPPI queue 1 -> ext Port 1 fifo1, CIR=100Mbit/s, EIR=1Mbit/s
> TC2 - prio 3, TX CPPI queue 2 -> ext Port 1 fifo2, CIR=200Mbit/s, EIR=2Mbit/s
> 
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
> Signed-off-by: Roger Quadros <rogerq@kernel.org>
> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
>  drivers/net/ethernet/ti/Kconfig          |   3 +-
>  drivers/net/ethernet/ti/am65-cpsw-nuss.c |   3 +
>  drivers/net/ethernet/ti/am65-cpsw-qos.c  | 255 ++++++++++++++++++++++-
>  drivers/net/ethernet/ti/am65-cpsw-qos.h  |  20 ++
>  4 files changed, 277 insertions(+), 4 deletions(-)

This breaks build due to undefined BYTES_PER_MBIT.
I'll fix it up and send another revision.

-- 
cheers,
-roger