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+* Texas Instruments CPSW ethernet driver
+
+Multiqueue & CBS & MQPRIO
+=====================================================================
+=====================================================================
+
+The cpsw has 3 CBS shapers for each external ports. This document
+describes MQPRIO and CBS Qdisc offload configuration for cpsw driver
+based on examples. It potentially can be used in audio video bridging
+(AVB) and time sensitive networking (TSN).
+
+The following examples were tested on AM572x EVM and BBB boards.
+
+Test setup
+==========
+
+Under consideration two examples with AM572x EVM running cpsw driver
+in dual_emac mode.
+
+Several prerequisites:
+- TX queues must be rated starting from txq0 that has highest priority
+- Traffic classes are used starting from 0, that has highest priority
+- CBS shapers should be used with rated queues
+- The bandwidth for CBS shapers has to be set a little bit more then
+ potential incoming rate, thus, rate of all incoming tx queues has
+ to be a little less
+- Real rates can differ, due to discreetness
+- Map skb-priority to txq is not enough, also skb-priority to l2 prio
+ map has to be created with ip or vconfig tool
+- Any l2/socket prio (0 - 7) for classes can be used, but for
+ simplicity default values are used: 3 and 2
+- only 2 classes tested: A and B, but checked and can work with more,
+ maximum allowed 4, but only for 3 rate can be set.
+
+Test setup for examples
+=======================
+ +-------------------------------+
+ |--+ |
+ | | Workstation0 |
+ |E | MAC 18:03:73:66:87:42 |
++-----------------------------+ +--|t | |
+| | 1 | E | | |h |./tsn_listener -d \ |
+| Target board: | 0 | t |--+ |0 | 18:03:73:66:87:42 -i eth0 \|
+| AM572x EVM | 0 | h | | | -s 1500 |
+| | 0 | 0 | |--+ |
+| Only 2 classes: |Mb +---| +-------------------------------+
+| class A, class B | |
+| | +---| +-------------------------------+
+| | 1 | E | |--+ |
+| | 0 | t | | | Workstation1 |
+| | 0 | h |--+ |E | MAC 20:cf:30:85:7d:fd |
+| |Mb | 1 | +--|t | |
++-----------------------------+ |h |./tsn_listener -d \ |
+ |0 | 20:cf:30:85:7d:fd -i eth0 \|
+ | | -s 1500 |
+ |--+ |
+ +-------------------------------+
+
+*********************************************************************
+*********************************************************************
+*********************************************************************
+Example 1: One port tx AVB configuration scheme for target board
+----------------------------------------------------------------------
+(prints and scheme for AM572x evm, applicable for single port boards)
+
+tc - traffic class
+txq - transmit queue
+p - priority
+f - fifo (cpsw fifo)
+S - shaper configured
+
++------------------------------------------------------------------+ u
+| +---------------+ +---------------+ +------+ +------+ | s
+| | | | | | | | | | e
+| | App 1 | | App 2 | | Apps | | Apps | | r
+| | Class A | | Class B | | Rest | | Rest | |
+| | Eth0 | | Eth0 | | Eth0 | | Eth1 | | s
+| | VLAN100 | | VLAN100 | | | | | | | | p
+| | 40 Mb/s | | 20 Mb/s | | | | | | | | a
+| | SO_PRIORITY=3 | | SO_PRIORITY=2 | | | | | | | | c
+| | | | | | | | | | | | | | e
+| +---|-----------+ +---|-----------+ +---|--+ +---|--+ |
++-----|------------------|------------------|--------|-------------+
+ +-+ +------------+ | |
+ | | +-----------------+ +--+
+ | | | |
++---|-------|-------------|-----------------------|----------------+
+| +----+ +----+ +----+ +----+ +----+ |
+| | p3 | | p2 | | p1 | | p0 | | p0 | | k
+| \ / \ / \ / \ / \ / | e
+| \ / \ / \ / \ / \ / | r
+| \/ \/ \/ \/ \/ | n
+| | | | | | e
+| | | +-----+ | | l
+| | | | | |
+| +----+ +----+ +----+ +----+ | s
+| |tc0 | |tc1 | |tc2 | |tc0 | | p
+| \ / \ / \ / \ / | a
+| \ / \ / \ / \ / | c
+| \/ \/ \/ \/ | e
+| | | +-----+ | |
+| | | | | | |
+| | | | | | |
+| | | | | | |
+| +----+ +----+ +----+ +----+ +----+ |
+| |txq0| |txq1| |txq2| |txq3| |txq4| |
+| \ / \ / \ / \ / \ / |
+| \ / \ / \ / \ / \ / |
+| \/ \/ \/ \/ \/ |
+| +-|------|------|------|--+ +--|--------------+ |
+| | | | | | | Eth0.100 | | Eth1 | |
++---|------|------|------|------------------------|----------------+
+ | | | | |
+ p p p p |
+ 3 2 0-1, 4-7 <- L2 priority |
+ | | | | |
+ | | | | |
++---|------|------|------|------------------------|----------------+
+| | | | | |----------+ |
+| +----+ +----+ +----+ +----+ +----+ |
+| |dma7| |dma6| |dma5| |dma4| |dma3| |
+| \ / \ / \ / \ / \ / | c
+| \S / \S / \ / \ / \ / | p
+| \/ \/ \/ \/ \/ | s
+| | | | +----- | | w
+| | | | | | |
+| | | | | | | d
+| +----+ +----+ +----+p p+----+ | r
+| | | | | | |o o| | | i
+| | f3 | | f2 | | f0 |r r| f0 | | v
+| |tc0 | |tc1 | |tc2 |t t|tc0 | | e
+| \CBS / \CBS / \CBS /1 2\CBS / | r
+| \S / \S / \ / \ / |
+| \/ \/ \/ \/ |
++------------------------------------------------------------------+
+========================================Eth==========================>
+
+1)
+// Add 4 tx queues, for interface Eth0, and 1 tx queue for Eth1
+$ ethtool -L eth0 rx 1 tx 5
+rx unmodified, ignoring
+
+2)
+// Check if num of queues is set correctly:
+$ ethtool -l eth0
+Channel parameters for eth0:
+Pre-set maximums:
+RX: 8
+TX: 8
+Other: 0
+Combined: 0
+Current hardware settings:
+RX: 1
+TX: 5
+Other: 0
+Combined: 0
+
+3)
+// TX queues must be rated starting from 0, so set bws for tx0 and tx1
+// Set rates 40 and 20 Mb/s appropriately.
+// Pay attention, real speed can differ a bit due to discreetness.
+// Leave last 2 tx queues not rated.
+$ echo 40 > /sys/class/net/eth0/queues/tx-0/tx_maxrate
+$ echo 20 > /sys/class/net/eth0/queues/tx-1/tx_maxrate
+
+4)
+// Check maximum rate of tx (cpdma) queues:
+$ cat /sys/class/net/eth0/queues/tx-*/tx_maxrate
+40
+20
+0
+0
+0
+
+5)
+// Map skb->priority to traffic class:
+// 3pri -> tc0, 2pri -> tc1, (0,1,4-7)pri -> tc2
+// Map traffic class to transmit queue:
+// tc0 -> txq0, tc1 -> txq1, tc2 -> (txq2, txq3)
+$ tc qdisc replace dev eth0 handle 100: parent root mqprio num_tc 3 \
+map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@2 hw 1
+
+5a)
+// As two interface sharing same set of tx queues, assign all traffic
+// coming to interface Eth1 to separate queue in order to not mix it
+// with traffic from interface Eth0, so use separate txq to send
+// packets to Eth1, so all prio -> tc0 and tc0 -> txq4
+// Here hw 0, so here still default configuration for eth1 in hw
+$ tc qdisc replace dev eth1 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@4 hw 0
+
+6)
+// Check classes settings
+$ tc -g class show dev eth0
++---(100:ffe2) mqprio
+| +---(100:3) mqprio
+| +---(100:4) mqprio
+|
++---(100:ffe1) mqprio
+| +---(100:2) mqprio
+|
++---(100:ffe0) mqprio
+ +---(100:1) mqprio
+
+$ tc -g class show dev eth1
++---(100:ffe0) mqprio
+ +---(100:5) mqprio
+
+7)
+// Set rate for class A - 41 Mbit (tc0, txq0) using CBS Qdisc
+// Set it +1 Mb for reserve (important!)
+// here only idle slope is important, others arg are ignored
+// Pay attention, real speed can differ a bit due to discreetness
+$ tc qdisc add dev eth0 parent 100:1 cbs locredit -1438 \
+hicredit 62 sendslope -959000 idleslope 41000 offload 1
+net eth0: set FIFO3 bw = 50
+
+8)
+// Set rate for class B - 21 Mbit (tc1, txq1) using CBS Qdisc:
+// Set it +1 Mb for reserve (important!)
+$ tc qdisc add dev eth0 parent 100:2 cbs locredit -1468 \
+hicredit 65 sendslope -979000 idleslope 21000 offload 1
+net eth0: set FIFO2 bw = 30
+
+9)
+// Create vlan 100 to map sk->priority to vlan qos
+$ ip link add link eth0 name eth0.100 type vlan id 100
+8021q: 802.1Q VLAN Support v1.8
+8021q: adding VLAN 0 to HW filter on device eth0
+8021q: adding VLAN 0 to HW filter on device eth1
+net eth0: Adding vlanid 100 to vlan filter
+
+10)
+// Map skb->priority to L2 prio, 1 to 1
+$ ip link set eth0.100 type vlan \
+egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
+
+11)
+// Check egress map for vlan 100
+$ cat /proc/net/vlan/eth0.100
+[...]
+INGRESS priority mappings: 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0
+EGRESS priority mappings: 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
+
+12)
+// Run your appropriate tools with socket option "SO_PRIORITY"
+// to 3 for class A and/or to 2 for class B
+// (I took at https://www.spinics.net/lists/netdev/msg460869.html)
+./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p3 -s 1500&
+./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p2 -s 1500&
+
+13)
+// run your listener on workstation (should be in same vlan)
+// (I took at https://www.spinics.net/lists/netdev/msg460869.html)
+./tsn_listener -d 18:03:73:66:87:42 -i enp5s0 -s 1500
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39000 kbps
+
+14)
+// Restore default configuration if needed
+$ ip link del eth0.100
+$ tc qdisc del dev eth1 root
+$ tc qdisc del dev eth0 root
+net eth0: Prev FIFO2 is shaped
+net eth0: set FIFO3 bw = 0
+net eth0: set FIFO2 bw = 0
+$ ethtool -L eth0 rx 1 tx 1
+
+*********************************************************************
+*********************************************************************
+*********************************************************************
+Example 2: Two port tx AVB configuration scheme for target board
+----------------------------------------------------------------------
+(prints and scheme for AM572x evm, for dual emac boards only)
+
++------------------------------------------------------------------+ u
+| +----------+ +----------+ +------+ +----------+ +----------+ | s
+| | | | | | | | | | | | e
+| | App 1 | | App 2 | | Apps | | App 3 | | App 4 | | r
+| | Class A | | Class B | | Rest | | Class B | | Class A | |
+| | Eth0 | | Eth0 | | | | | Eth1 | | Eth1 | | s
+| | VLAN100 | | VLAN100 | | | | | VLAN100 | | VLAN100 | | p
+| | 40 Mb/s | | 20 Mb/s | | | | | 10 Mb/s | | 30 Mb/s | | a
+| | SO_PRI=3 | | SO_PRI=2 | | | | | SO_PRI=3 | | SO_PRI=2 | | c
+| | | | | | | | | | | | | | | | | e
+| +---|------+ +---|------+ +---|--+ +---|------+ +---|------+ |
++-----|-------------|-------------|---------|-------------|--------+
+ +-+ +-------+ | +----------+ +----+
+ | | +-------+------+ | |
+ | | | | | |
++---|-------|-------------|--------------|-------------|-------|---+
+| +----+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ |
+| | p3 | | p2 | | p1 | | p0 | | p0 | | p1 | | p2 | | p3 | | k
+| \ / \ / \ / \ / \ / \ / \ / \ / | e
+| \ / \ / \ / \ / \ / \ / \ / \ / | r
+| \/ \/ \/ \/ \/ \/ \/ \/ | n
+| | | | | | | | e
+| | | +----+ +----+ | | | l
+| | | | | | | |
+| +----+ +----+ +----+ +----+ +----+ +----+ | s
+| |tc0 | |tc1 | |tc2 | |tc2 | |tc1 | |tc0 | | p
+| \ / \ / \ / \ / \ / \ / | a
+| \ / \ / \ / \ / \ / \ / | c
+| \/ \/ \/ \/ \/ \/ | e
+| | | +-----+ +-----+ | | |
+| | | | | | | | | |
+| | | | | | | | | |
+| | | | | E E | | | | |
+| +----+ +----+ +----+ +----+ t t +----+ +----+ +----+ +----+ |
+| |txq0| |txq1| |txq4| |txq5| h h |txq6| |txq7| |txq3| |txq2| |
+| \ / \ / \ / \ / 0 1 \ / \ / \ / \ / |
+| \ / \ / \ / \ / . . \ / \ / \ / \ / |
+| \/ \/ \/ \/ 1 1 \/ \/ \/ \/ |
+| +-|------|------|------|--+ 0 0 +-|------|------|------|--+ |
+| | | | | | | 0 0 | | | | | | |
++---|------|------|------|---------------|------|------|------|----+
+ | | | | | | | |
+ p p p p p p p p
+ 3 2 0-1, 4-7 <-L2 pri-> 0-1, 4-7 2 3
+ | | | | | | | |
+ | | | | | | | |
++---|------|------|------|---------------|------|------|------|----+
+| | | | | | | | | |
+| +----+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ |
+| |dma7| |dma6| |dma3| |dma2| |dma1| |dma0| |dma4| |dma5| |
+| \ / \ / \ / \ / \ / \ / \ / \ / | c
+| \S / \S / \ / \ / \ / \ / \S / \S / | p
+| \/ \/ \/ \/ \/ \/ \/ \/ | s
+| | | | +----- | | | | | w
+| | | | | +----+ | | | |
+| | | | | | | | | | d
+| +----+ +----+ +----+p p+----+ +----+ +----+ | r
+| | | | | | |o o| | | | | | | i
+| | f3 | | f2 | | f0 |r CPSW r| f3 | | f2 | | f0 | | v
+| |tc0 | |tc1 | |tc2 |t t|tc0 | |tc1 | |tc2 | | e
+| \CBS / \CBS / \CBS /1 2\CBS / \CBS / \CBS / | r
+| \S / \S / \ / \S / \S / \ / |
+| \/ \/ \/ \/ \/ \/ |
++------------------------------------------------------------------+
+========================================Eth==========================>
+
+1)
+// Add 8 tx queues, for interface Eth0, but they are common, so are accessed
+// by two interfaces Eth0 and Eth1.
+$ ethtool -L eth1 rx 1 tx 8
+rx unmodified, ignoring
+
+2)
+// Check if num of queues is set correctly:
+$ ethtool -l eth0
+Channel parameters for eth0:
+Pre-set maximums:
+RX: 8
+TX: 8
+Other: 0
+Combined: 0
+Current hardware settings:
+RX: 1
+TX: 8
+Other: 0
+Combined: 0
+
+3)
+// TX queues must be rated starting from 0, so set bws for tx0 and tx1 for Eth0
+// and for tx2 and tx3 for Eth1. That is, rates 40 and 20 Mb/s appropriately
+// for Eth0 and 30 and 10 Mb/s for Eth1.
+// Real speed can differ a bit due to discreetness
+// Leave last 4 tx queues as not rated
+$ echo 40 > /sys/class/net/eth0/queues/tx-0/tx_maxrate
+$ echo 20 > /sys/class/net/eth0/queues/tx-1/tx_maxrate
+$ echo 30 > /sys/class/net/eth1/queues/tx-2/tx_maxrate
+$ echo 10 > /sys/class/net/eth1/queues/tx-3/tx_maxrate
+
+4)
+// Check maximum rate of tx (cpdma) queues:
+$ cat /sys/class/net/eth0/queues/tx-*/tx_maxrate
+40
+20
+30
+10
+0
+0
+0
+0
+
+5)
+// Map skb->priority to traffic class for Eth0:
+// 3pri -> tc0, 2pri -> tc1, (0,1,4-7)pri -> tc2
+// Map traffic class to transmit queue:
+// tc0 -> txq0, tc1 -> txq1, tc2 -> (txq4, txq5)
+$ tc qdisc replace dev eth0 handle 100: parent root mqprio num_tc 3 \
+map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@4 hw 1
+
+6)
+// Check classes settings
+$ tc -g class show dev eth0
++---(100:ffe2) mqprio
+| +---(100:5) mqprio
+| +---(100:6) mqprio
+|
++---(100:ffe1) mqprio
+| +---(100:2) mqprio
+|
++---(100:ffe0) mqprio
+ +---(100:1) mqprio
+
+7)
+// Set rate for class A - 41 Mbit (tc0, txq0) using CBS Qdisc for Eth0
+// here only idle slope is important, others ignored
+// Real speed can differ a bit due to discreetness
+$ tc qdisc add dev eth0 parent 100:1 cbs locredit -1470 \
+hicredit 62 sendslope -959000 idleslope 41000 offload 1
+net eth0: set FIFO3 bw = 50
+
+8)
+// Set rate for class B - 21 Mbit (tc1, txq1) using CBS Qdisc for Eth0
+$ tc qdisc add dev eth0 parent 100:2 cbs locredit -1470 \
+hicredit 65 sendslope -979000 idleslope 21000 offload 1
+net eth0: set FIFO2 bw = 30
+
+9)
+// Create vlan 100 to map sk->priority to vlan qos for Eth0
+$ ip link add link eth0 name eth0.100 type vlan id 100
+net eth0: Adding vlanid 100 to vlan filter
+
+10)
+// Map skb->priority to L2 prio for Eth0.100, one to one
+$ ip link set eth0.100 type vlan \
+egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
+
+11)
+// Check egress map for vlan 100
+$ cat /proc/net/vlan/eth0.100
+[...]
+INGRESS priority mappings: 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0
+EGRESS priority mappings: 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
+
+12)
+// Map skb->priority to traffic class for Eth1:
+// 3pri -> tc0, 2pri -> tc1, (0,1,4-7)pri -> tc2
+// Map traffic class to transmit queue:
+// tc0 -> txq2, tc1 -> txq3, tc2 -> (txq6, txq7)
+$ tc qdisc replace dev eth1 handle 100: parent root mqprio num_tc 3 \
+map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@2 1@3 2@6 hw 1
+
+13)
+// Check classes settings
+$ tc -g class show dev eth1
++---(100:ffe2) mqprio
+| +---(100:7) mqprio
+| +---(100:8) mqprio
+|
++---(100:ffe1) mqprio
+| +---(100:4) mqprio
+|
++---(100:ffe0) mqprio
+ +---(100:3) mqprio
+
+14)
+// Set rate for class A - 31 Mbit (tc0, txq2) using CBS Qdisc for Eth1
+// here only idle slope is important, others ignored, but calculated
+// for interface speed - 100Mb for eth1 port.
+// Set it +1 Mb for reserve (important!)
+$ tc qdisc add dev eth1 parent 100:3 cbs locredit -1035 \
+hicredit 465 sendslope -69000 idleslope 31000 offload 1
+net eth1: set FIFO3 bw = 31
+
+15)
+// Set rate for class B - 11 Mbit (tc1, txq3) using CBS Qdisc for Eth1
+// Set it +1 Mb for reserve (important!)
+$ tc qdisc add dev eth1 parent 100:4 cbs locredit -1335 \
+hicredit 405 sendslope -89000 idleslope 11000 offload 1
+net eth1: set FIFO2 bw = 11
+
+16)
+// Create vlan 100 to map sk->priority to vlan qos for Eth1
+$ ip link add link eth1 name eth1.100 type vlan id 100
+net eth1: Adding vlanid 100 to vlan filter
+
+17)
+// Map skb->priority to L2 prio for Eth1.100, one to one
+$ ip link set eth1.100 type vlan \
+egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
+
+18)
+// Check egress map for vlan 100
+$ cat /proc/net/vlan/eth1.100
+[...]
+INGRESS priority mappings: 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0
+EGRESS priority mappings: 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
+
+19)
+// Run appropriate tools with socket option "SO_PRIORITY" to 3
+// for class A and to 2 for class B. For both interfaces
+./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p2 -s 1500&
+./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p3 -s 1500&
+./tsn_talker -d 20:cf:30:85:7d:fd -i eth1.100 -p2 -s 1500&
+./tsn_talker -d 20:cf:30:85:7d:fd -i eth1.100 -p3 -s 1500&
+
+20)
+// run your listener on workstation (should be in same vlan)
+// (I took at https://www.spinics.net/lists/netdev/msg460869.html)
+./tsn_listener -d 18:03:73:66:87:42 -i enp5s0 -s 1500
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39012 kbps
+Receiving data rate: 39000 kbps
+
+21)
+// Restore default configuration if needed
+$ ip link del eth1.100
+$ ip link del eth0.100
+$ tc qdisc del dev eth1 root
+net eth1: Prev FIFO2 is shaped
+net eth1: set FIFO3 bw = 0
+net eth1: set FIFO2 bw = 0
+$ tc qdisc del dev eth0 root
+net eth0: Prev FIFO2 is shaped
+net eth0: set FIFO3 bw = 0
+net eth0: set FIFO2 bw = 0
+$ ethtool -L eth0 rx 1 tx 1
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 18:15:30 +0000