Merge branch 'stmmac-per-queue-stats'

Vijayakannan Ayyathurai says:

====================
net: stmmac: Add ethtool per-queue statistic

Adding generic ethtool per-queue statistic framework to display the
statistics for each rx/tx queue. In future, users can avail it to add
more per-queue specific counters. Number of rx/tx queues displayed is
depending on the available rx/tx queues in that particular MAC config
and this number is limited up to the MTL_MAX_{RX|TX}_QUEUES defined
in the driver.

Ethtool per-queue statistic display will look like below, when users
start adding more counters.

Example - 1:
 q0_tx_statA:
 q0_tx_statB:
 q0_tx_statC:
 |
 q0_tx_statX:
 .
 .
 .
 qMAX_tx_statA:
 qMAX_tx_statB:
 qMAX_tx_statC:
 |
 qMAX_tx_statX:

 q0_rx_statA:
 q0_rx_statB:
 q0_rx_statC:
 |
 q0_rx_statX:
 .
 .
 .
 qMAX_rx_statA:
 qMAX_rx_statB:
 qMAX_rx_statC:
 |
 qMAX_rx_statX:

Example - 2: Ping test using the tx queue 3.

$ tc qdisc add dev enp0s30f4 root mqprio num_tc 2 map 1 0 0 0 0 0 0 0
 0 0 0 0 0 0 0 0 queues 3@0 1@3 hw 0

Statistic before ping:
---------------------
$ ethtool -S enp0s30f4

[ snip ]
     q3_tx_pkt_n: 7916
     q3_tx_irq_n: 316
[ snip ]

$ cat /proc/interrupts

[ snip ]
 143:          0          0          0        316          0          0

         0          0  IR-PCI-MSI 499719-edge      enp0s30f4:tx-3
[ snip ]

$ ping -I enp0s30f4 192.168.1.10 -i 0.01 -c 100 > /dev/null

Statistic after ping:
---------------------
$ ethtool -S enp0s30f4

[ snip ]
     q3_tx_pkt_n: 8016
     q3_tx_irq_n: 320
[ snip ]

$ cat /proc/interrupts

[ snip ]
143:          0          0          0        320          0          0

         0          0  IR-PCI-MSI 499719-edge      enp0s30f4:tx-3
[ snip ]
====================

Signed-off-by: David S. Miller <davem@davemloft.net>