[PATCH net-next v6 12/15] ibmveth: Report MQ-aware RX counts in ethtool get_channels

Report MQ-aware channel limits and counts from get_channels():

  - max_rx is IBMVETH_MAX_RX_QUEUES when MQ firmware is enabled, else 1
  - rx_count tracks the driver's published num_rx_queues

Previously get_channels() mirrored netdev->real_num_rx_queues for both
fields, which under-reports max_rx on MQ firmware and can disagree with
the driver's private RX count before the next open.

This patch only reports. set_channels() still reads only tx_count, so
an RX channel request returns success without changing anything;
raising max_rx widens the range of requests that behave that way from
the live count to IBMVETH_MAX_RX_QUEUES. Patch 14 closes it, with
set_channels() reading rx_count and calling
ibmveth_resize_rx_channels(), and patch 15 completes the down-path
publish/rollback and caps max_rx once mq_fallback latches.

Keep this out of the stats patch: channel reporting is ethtool -l ABI,
independent of per-queue counters, so it can be reviewed and blamed on
its own.

Signed-off-by: Mingming Cao <[email protected]>
Reviewed-by: Dave Marquardt <[email protected]>
Tested-by: Shaik Abdulla <[email protected]>
---

Changes in v5:
- get_channels rx_count via get_num_rx_queues() (READ_ONCE consistency)
- New peel: get_channels from v4 stats -> tip P12 (14->15)
- get_channels: max_rx = MAX_RX_QUEUES when MQ else 1; rx_count =
  get_num_rx_queues() (was mirroring real_num_rx_queues for both)

 drivers/net/ethernet/ibm/ibmveth.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index f4fddfa56571..4f2d956b4c89 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -2537,11 +2537,16 @@ static void ibmveth_get_ethtool_stats(struct net_device *dev,
 static void ibmveth_get_channels(struct net_device *netdev,
 				 struct ethtool_channels *channels)
 {
+	struct ibmveth_adapter *adapter = netdev_priv(netdev);
+
 	channels->max_tx = ibmveth_real_max_tx_queues();
 	channels->tx_count = netdev->real_num_tx_queues;
 
-	channels->max_rx = netdev->real_num_rx_queues;
-	channels->rx_count = netdev->real_num_rx_queues;
+	if (adapter->multi_queue)
+		channels->max_rx = IBMVETH_MAX_RX_QUEUES;
+	else
+		channels->max_rx = 1;
+	channels->rx_count = ibmveth_get_num_rx_queues(adapter);
 }
 
 static int ibmveth_set_channels(struct net_device *netdev,
-- 
2.50.1 (Apple Git-155)