amd-xgbe: Add support for per DMA channel interrupts

This patch provides support for interrupts that are generated by the
Tx/Rx DMA channel pairs of the device.  This allows for Tx and Rx
processing to run across multiple processsors.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index b3719f1..ac3d319 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -481,17 +481,21 @@
 
 		if (channel->tx_ring) {
 			/* Enable the following Tx interrupts
-			 *   TIE  - Transmit Interrupt Enable (unless polling)
+			 *   TIE  - Transmit Interrupt Enable (unless using
+			 *          per channel interrupts)
 			 */
-			XGMAC_SET_BITS(dma_ch_ier, DMA_CH_IER, TIE, 1);
+			if (!pdata->per_channel_irq)
+				XGMAC_SET_BITS(dma_ch_ier, DMA_CH_IER, TIE, 1);
 		}
 		if (channel->rx_ring) {
 			/* Enable following Rx interrupts
 			 *   RBUE - Receive Buffer Unavailable Enable
-			 *   RIE  - Receive Interrupt Enable
+			 *   RIE  - Receive Interrupt Enable (unless using
+			 *          per channel interrupts)
 			 */
 			XGMAC_SET_BITS(dma_ch_ier, DMA_CH_IER, RBUE, 1);
-			XGMAC_SET_BITS(dma_ch_ier, DMA_CH_IER, RIE, 1);
+			if (!pdata->per_channel_irq)
+				XGMAC_SET_BITS(dma_ch_ier, DMA_CH_IER, RIE, 1);
 		}
 
 		XGMAC_DMA_IOWRITE(channel, DMA_CH_IER, dma_ch_ier);