stmmac: enable rx queues

When the hardware is synthesized with multiple queues, all queues are
disabled for default. This patch adds the rx queues configuration.
This patch was successfully tested in a Synopsys QoS Reference design.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -323,6 +323,9 @@ struct dma_features {
 	/* TX and RX number of channels */
 	unsigned int number_rx_channel;
 	unsigned int number_tx_channel;
+	/* TX and RX number of queues */
+	unsigned int number_rx_queues;
+	unsigned int number_tx_queues;
 	/* Alternate (enhanced) DESC mode */
 	unsigned int enh_desc;
 };
@@ -454,6 +457,8 @@ struct stmmac_ops {
 	void (*core_init)(struct mac_device_info *hw, int mtu);
 	/* Enable and verify that the IPC module is supported */
 	int (*rx_ipc)(struct mac_device_info *hw);
+	/* Enable RX Queues */
+	void (*rx_queue_enable)(struct mac_device_info *hw, u32 queue);
 	/* Dump MAC registers */
 	void (*dump_regs)(struct mac_device_info *hw);
 	/* Handle extra events on specific interrupts hw dependent */

drivers/net/ethernet/stmicro/stmmac/dwmac4.h

@@ -22,6 +22,7 @@
 #define GMAC_HASH_TAB_32_63		0x00000014
 #define GMAC_RX_FLOW_CTRL		0x00000090
 #define GMAC_QX_TX_FLOW_CTRL(x)		(0x70 + x * 4)
+#define GMAC_RXQ_CTRL0			0x000000a0
 #define GMAC_INT_STATUS			0x000000b0
 #define GMAC_INT_EN			0x000000b4
 #define GMAC_PCS_BASE			0x000000e0
@@ -44,6 +45,11 @@
 
 #define GMAC_MAX_PERFECT_ADDRESSES	128
 
+/* MAC RX Queue Enable */
+#define GMAC_RX_QUEUE_CLEAR(queue)	~(GENMASK(1, 0) << ((queue) * 2))
+#define GMAC_RX_AV_QUEUE_ENABLE(queue)	BIT((queue) * 2)
+#define GMAC_RX_DCB_QUEUE_ENABLE(queue)	BIT(((queue) * 2) + 1)
+
 /* MAC Flow Control RX */
 #define GMAC_RX_FLOW_CTRL_RFE		BIT(0)
 
@@ -133,6 +139,8 @@ enum power_event {
 /* MAC HW features2 bitmap */
 #define GMAC_HW_FEAT_TXCHCNT		GENMASK(21, 18)
 #define GMAC_HW_FEAT_RXCHCNT		GENMASK(15, 12)
+#define GMAC_HW_FEAT_TXQCNT		GENMASK(9, 6)
+#define GMAC_HW_FEAT_RXQCNT		GENMASK(3, 0)
 
 /* MAC HW ADDR regs */
 #define GMAC_HI_DCS			GENMASK(18, 16)

drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c

@@ -59,6 +59,17 @@ static void dwmac4_core_init(struct mac_device_info *hw, int mtu)
 	writel(value, ioaddr + GMAC_INT_EN);
 }
 
+static void dwmac4_rx_queue_enable(struct mac_device_info *hw, u32 queue)
+{
+	void __iomem *ioaddr = hw->pcsr;
+	u32 value = readl(ioaddr + GMAC_RXQ_CTRL0);
+
+	value &= GMAC_RX_QUEUE_CLEAR(queue);
+	value |= GMAC_RX_AV_QUEUE_ENABLE(queue);
+
+	writel(value, ioaddr + GMAC_RXQ_CTRL0);
+}
+
 static void dwmac4_dump_regs(struct mac_device_info *hw)
 {
 	void __iomem *ioaddr = hw->pcsr;
@@ -392,6 +403,7 @@ static void dwmac4_debug(void __iomem *ioaddr, struct stmmac_extra_stats *x)
 static const struct stmmac_ops dwmac4_ops = {
 	.core_init = dwmac4_core_init,
 	.rx_ipc = dwmac4_rx_ipc_enable,
+	.rx_queue_enable = dwmac4_rx_queue_enable,
 	.dump_regs = dwmac4_dump_regs,
 	.host_irq_status = dwmac4_irq_status,
 	.flow_ctrl = dwmac4_flow_ctrl,

drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c

@@ -303,6 +303,11 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr,
 		((hw_cap & GMAC_HW_FEAT_RXCHCNT) >> 12) + 1;
 	dma_cap->number_tx_channel =
 		((hw_cap & GMAC_HW_FEAT_TXCHCNT) >> 18) + 1;
+	/* TX and RX number of queues */
+	dma_cap->number_rx_queues =
+		((hw_cap & GMAC_HW_FEAT_RXQCNT) >> 0) + 1;
+	dma_cap->number_tx_queues =
+		((hw_cap & GMAC_HW_FEAT_TXQCNT) >> 6) + 1;
 
 	/* IEEE 1588-2002 */
 	dma_cap->time_stamp = 0;

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1270,6 +1270,28 @@ static void free_dma_desc_resources(struct stmmac_priv *priv)
 	kfree(priv->tx_skbuff);
 }
 
+/**
+ *  stmmac_mac_enable_rx_queues - Enable MAC rx queues
+ *  @priv: driver private structure
+ *  Description: It is used for enabling the rx queues in the MAC
+ */
+static void stmmac_mac_enable_rx_queues(struct stmmac_priv *priv)
+{
+	int rx_count = priv->dma_cap.number_rx_queues;
+	int queue = 0;
+
+	/* If GMAC does not have multiple queues, then this is not necessary*/
+	if (rx_count == 1)
+		return;
+
+	/**
+	 *  If the core is synthesized with multiple rx queues / multiple
+	 *  dma channels, then rx queues will be disabled by default.
+	 *  For now only rx queue 0 is enabled.
+	 */
+	priv->hw->mac->rx_queue_enable(priv->hw, queue);
+}
+
 /**
  *  stmmac_dma_operation_mode - HW DMA operation mode
  *  @priv: driver private structure
@@ -1691,6 +1713,10 @@ static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
 	/* Initialize the MAC Core */
 	priv->hw->mac->core_init(priv->hw, dev->mtu);
 
+	/* Initialize MAC RX Queues */
+	if (priv->hw->mac->rx_queue_enable)
+		stmmac_mac_enable_rx_queues(priv);
+
 	ret = priv->hw->mac->rx_ipc(priv->hw);
 	if (!ret) {
 		netdev_warn(priv->dev, "RX IPC Checksum Offload disabled\n");