net: stmmac: Add multi-channel support

DW GMAC v3.73 can be equipped with the Audio Video (AV) feature which
enables transmission of time-sensitive traffic over bridged local area
networks (DWC Ethernet QoS Product). In that case there can be up to two
additional DMA-channels available with no Tx COE support (unless there is
vendor-specific IP-core alterations). Each channel is implemented as a
separate Control and Status register (CSR) for managing the transmit and
receive functions, descriptor handling, and interrupt handling.

Add the multi-channels DW GMAC controllers support just by making sure the
already implemented DMA-configs are performed on the per-channel basis.

Note the only currently known instance of the multi-channel DW GMAC
IP-core is the LS2K2000 GNET controller, which has been released with the
vendor-specific feature extension of having eight DMA-channels. The device
support will be added in one of the following up commits.
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Yinggang Gu <guyinggang@loongson.cn>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c

@@ -395,7 +395,7 @@ static void sun8i_dwmac_dma_start_tx(struct stmmac_priv *priv,
 	writel(v, ioaddr + EMAC_TX_CTL1);
 }
 
-static void sun8i_dwmac_enable_dma_transmission(void __iomem *ioaddr)
+static void sun8i_dwmac_enable_dma_transmission(void __iomem *ioaddr, u32 chan)
 {
 	u32 v;
 

drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c

@@ -70,15 +70,17 @@ static void dwmac1000_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
 	writel(value, ioaddr + DMA_AXI_BUS_MODE);
 }
 
-static void dwmac1000_dma_init(void __iomem *ioaddr,
-			       struct stmmac_dma_cfg *dma_cfg)
+static void dwmac1000_dma_init_channel(struct stmmac_priv *priv,
+				       void __iomem *ioaddr,
+				       struct stmmac_dma_cfg *dma_cfg, u32 chan)
 {
-	u32 value = readl(ioaddr + DMA_BUS_MODE);
 	int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
 	int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;
+	u32 value;
 
-	/*
-	 * Set the DMA PBL (Programmable Burst Length) mode.
+	value = readl(ioaddr + DMA_CHAN_BUS_MODE(chan));
+
+	/* Set the DMA PBL (Programmable Burst Length) mode.
 	 *
 	 * Note: before stmmac core 3.50 this mode bit was 4xPBL, and
 	 * post 3.5 mode bit acts as 8*PBL.
@@ -104,10 +106,10 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
 	if (dma_cfg->aal)
 		value |= DMA_BUS_MODE_AAL;
 
-	writel(value, ioaddr + DMA_BUS_MODE);
+	writel(value, ioaddr + DMA_CHAN_BUS_MODE(chan));
 
 	/* Mask interrupts by writing to CSR7 */
-	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
+	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_CHAN_INTR_ENA(chan));
 }
 
 static void dwmac1000_dma_init_rx(struct stmmac_priv *priv,
@@ -116,7 +118,7 @@ static void dwmac1000_dma_init_rx(struct stmmac_priv *priv,
 				  dma_addr_t dma_rx_phy, u32 chan)
 {
 	/* RX descriptor base address list must be written into DMA CSR3 */
-	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_RCV_BASE_ADDR);
+	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_CHAN_RCV_BASE_ADDR(chan));
 }
 
 static void dwmac1000_dma_init_tx(struct stmmac_priv *priv,
@@ -125,7 +127,7 @@ static void dwmac1000_dma_init_tx(struct stmmac_priv *priv,
 				  dma_addr_t dma_tx_phy, u32 chan)
 {
 	/* TX descriptor base address list must be written into DMA CSR4 */
-	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_TX_BASE_ADDR);
+	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_CHAN_TX_BASE_ADDR(chan));
 }
 
 static u32 dwmac1000_configure_fc(u32 csr6, int rxfifosz)
@@ -153,7 +155,7 @@ static void dwmac1000_dma_operation_mode_rx(struct stmmac_priv *priv,
 					    void __iomem *ioaddr, int mode,
 					    u32 channel, int fifosz, u8 qmode)
 {
-	u32 csr6 = readl(ioaddr + DMA_CONTROL);
+	u32 csr6 = readl(ioaddr + DMA_CHAN_CONTROL(channel));
 
 	if (mode == SF_DMA_MODE) {
 		pr_debug("GMAC: enable RX store and forward mode\n");
@@ -175,14 +177,14 @@ static void dwmac1000_dma_operation_mode_rx(struct stmmac_priv *priv,
 	/* Configure flow control based on rx fifo size */
 	csr6 = dwmac1000_configure_fc(csr6, fifosz);
 
-	writel(csr6, ioaddr + DMA_CONTROL);
+	writel(csr6, ioaddr + DMA_CHAN_CONTROL(channel));
 }
 
 static void dwmac1000_dma_operation_mode_tx(struct stmmac_priv *priv,
 					    void __iomem *ioaddr, int mode,
 					    u32 channel, int fifosz, u8 qmode)
 {
-	u32 csr6 = readl(ioaddr + DMA_CONTROL);
+	u32 csr6 = readl(ioaddr + DMA_CHAN_CONTROL(channel));
 
 	if (mode == SF_DMA_MODE) {
 		pr_debug("GMAC: enable TX store and forward mode\n");
@@ -209,7 +211,7 @@ static void dwmac1000_dma_operation_mode_tx(struct stmmac_priv *priv,
 			csr6 |= DMA_CONTROL_TTC_256;
 	}
 
-	writel(csr6, ioaddr + DMA_CONTROL);
+	writel(csr6, ioaddr + DMA_CHAN_CONTROL(channel));
 }
 
 static void dwmac1000_dump_dma_regs(struct stmmac_priv *priv,
@@ -271,12 +273,12 @@ static int dwmac1000_get_hw_feature(void __iomem *ioaddr,
 static void dwmac1000_rx_watchdog(struct stmmac_priv *priv,
 				  void __iomem *ioaddr, u32 riwt, u32 queue)
 {
-	writel(riwt, ioaddr + DMA_RX_WATCHDOG);
+	writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(queue));
 }
 
 const struct stmmac_dma_ops dwmac1000_dma_ops = {
 	.reset = dwmac_dma_reset,
-	.init = dwmac1000_dma_init,
+	.init_chan = dwmac1000_dma_init_channel,
 	.init_rx_chan = dwmac1000_dma_init_rx,
 	.init_tx_chan = dwmac1000_dma_init_tx,
 	.axi = dwmac1000_dma_axi,

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

@@ -22,6 +22,31 @@
 #define DMA_INTR_ENA		0x0000101c	/* Interrupt Enable */
 #define DMA_MISSED_FRAME_CTR	0x00001020	/* Missed Frame Counter */
 
+/* Following DMA defines are channels oriented */
+#define DMA_CHAN_BASE_OFFSET			0x100
+
+static inline u32 dma_chan_base_addr(u32 base, u32 chan)
+{
+	return base + chan * DMA_CHAN_BASE_OFFSET;
+}
+
+#define DMA_CHAN_BUS_MODE(chan)	dma_chan_base_addr(DMA_BUS_MODE, chan)
+#define DMA_CHAN_XMT_POLL_DEMAND(chan)	\
+				dma_chan_base_addr(DMA_XMT_POLL_DEMAND, chan)
+#define DMA_CHAN_RCV_POLL_DEMAND(chan)	\
+				dma_chan_base_addr(DMA_RCV_POLL_DEMAND, chan)
+#define DMA_CHAN_RCV_BASE_ADDR(chan)	\
+				dma_chan_base_addr(DMA_RCV_BASE_ADDR, chan)
+#define DMA_CHAN_TX_BASE_ADDR(chan)	\
+				dma_chan_base_addr(DMA_TX_BASE_ADDR, chan)
+#define DMA_CHAN_STATUS(chan)	dma_chan_base_addr(DMA_STATUS, chan)
+#define DMA_CHAN_CONTROL(chan)	dma_chan_base_addr(DMA_CONTROL, chan)
+#define DMA_CHAN_INTR_ENA(chan)	dma_chan_base_addr(DMA_INTR_ENA, chan)
+#define DMA_CHAN_MISSED_FRAME_CTR(chan)	\
+				dma_chan_base_addr(DMA_MISSED_FRAME_CTR, chan)
+#define DMA_CHAN_RX_WATCHDOG(chan)	\
+				dma_chan_base_addr(DMA_RX_WATCHDOG, chan)
+
 /* SW Reset */
 #define DMA_BUS_MODE_SFT_RESET	0x00000001	/* Software Reset */
 
@@ -152,7 +177,7 @@
 #define NUM_DWMAC1000_DMA_REGS	23
 #define NUM_DWMAC4_DMA_REGS	27
 
-void dwmac_enable_dma_transmission(void __iomem *ioaddr);
+void dwmac_enable_dma_transmission(void __iomem *ioaddr, u32 chan);
 void dwmac_enable_dma_irq(struct stmmac_priv *priv, void __iomem *ioaddr,
 			  u32 chan, bool rx, bool tx);
 void dwmac_disable_dma_irq(struct stmmac_priv *priv, void __iomem *ioaddr,

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

@@ -28,65 +28,65 @@ int dwmac_dma_reset(void __iomem *ioaddr)
 }
 
 /* CSR1 enables the transmit DMA to check for new descriptor */
-void dwmac_enable_dma_transmission(void __iomem *ioaddr)
+void dwmac_enable_dma_transmission(void __iomem *ioaddr, u32 chan)
 {
-	writel(1, ioaddr + DMA_XMT_POLL_DEMAND);
+	writel(1, ioaddr + DMA_CHAN_XMT_POLL_DEMAND(chan));
 }
 
 void dwmac_enable_dma_irq(struct stmmac_priv *priv, void __iomem *ioaddr,
 			  u32 chan, bool rx, bool tx)
 {
-	u32 value = readl(ioaddr + DMA_INTR_ENA);
+	u32 value = readl(ioaddr + DMA_CHAN_INTR_ENA(chan));
 
 	if (rx)
 		value |= DMA_INTR_DEFAULT_RX;
 	if (tx)
 		value |= DMA_INTR_DEFAULT_TX;
 
-	writel(value, ioaddr + DMA_INTR_ENA);
+	writel(value, ioaddr + DMA_CHAN_INTR_ENA(chan));
 }
 
 void dwmac_disable_dma_irq(struct stmmac_priv *priv, void __iomem *ioaddr,
 			   u32 chan, bool rx, bool tx)
 {
-	u32 value = readl(ioaddr + DMA_INTR_ENA);
+	u32 value = readl(ioaddr + DMA_CHAN_INTR_ENA(chan));
 
 	if (rx)
 		value &= ~DMA_INTR_DEFAULT_RX;
 	if (tx)
 		value &= ~DMA_INTR_DEFAULT_TX;
 
-	writel(value, ioaddr + DMA_INTR_ENA);
+	writel(value, ioaddr + DMA_CHAN_INTR_ENA(chan));
 }
 
 void dwmac_dma_start_tx(struct stmmac_priv *priv, void __iomem *ioaddr,
 			u32 chan)
 {
-	u32 value = readl(ioaddr + DMA_CONTROL);
+	u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
 	value |= DMA_CONTROL_ST;
-	writel(value, ioaddr + DMA_CONTROL);
+	writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
 }
 
 void dwmac_dma_stop_tx(struct stmmac_priv *priv, void __iomem *ioaddr, u32 chan)
 {
-	u32 value = readl(ioaddr + DMA_CONTROL);
+	u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
 	value &= ~DMA_CONTROL_ST;
-	writel(value, ioaddr + DMA_CONTROL);
+	writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
 }
 
 void dwmac_dma_start_rx(struct stmmac_priv *priv, void __iomem *ioaddr,
 			u32 chan)
 {
-	u32 value = readl(ioaddr + DMA_CONTROL);
+	u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
 	value |= DMA_CONTROL_SR;
-	writel(value, ioaddr + DMA_CONTROL);
+	writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
 }
 
 void dwmac_dma_stop_rx(struct stmmac_priv *priv, void __iomem *ioaddr, u32 chan)
 {
-	u32 value = readl(ioaddr + DMA_CONTROL);
+	u32 value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
 	value &= ~DMA_CONTROL_SR;
-	writel(value, ioaddr + DMA_CONTROL);
+	writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
 }
 
 #ifdef DWMAC_DMA_DEBUG
@@ -165,7 +165,7 @@ int dwmac_dma_interrupt(struct stmmac_priv *priv, void __iomem *ioaddr,
 	struct stmmac_pcpu_stats *stats = this_cpu_ptr(priv->xstats.pcpu_stats);
 	int ret = 0;
 	/* read the status register (CSR5) */
-	u32 intr_status = readl(ioaddr + DMA_STATUS);
+	u32 intr_status = readl(ioaddr + DMA_CHAN_STATUS(chan));
 
 #ifdef DWMAC_DMA_DEBUG
 	/* Enable it to monitor DMA rx/tx status in case of critical problems */

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

@@ -197,7 +197,7 @@ struct stmmac_dma_ops {
 	/* To track extra statistic (if supported) */
 	void (*dma_diagnostic_fr)(struct stmmac_extra_stats *x,
 				  void __iomem *ioaddr);
-	void (*enable_dma_transmission) (void __iomem *ioaddr);
+	void (*enable_dma_transmission)(void __iomem *ioaddr, u32 chan);
 	void (*enable_dma_irq)(struct stmmac_priv *priv, void __iomem *ioaddr,
 			       u32 chan, bool rx, bool tx);
 	void (*disable_dma_irq)(struct stmmac_priv *priv, void __iomem *ioaddr,

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

@@ -2367,9 +2367,11 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 	if (txfifosz == 0)
 		txfifosz = priv->dma_cap.tx_fifo_size;
 
-	/* Adjust for real per queue fifo size */
-	rxfifosz /= rx_channels_count;
-	txfifosz /= tx_channels_count;
+	/* Split up the shared Tx/Rx FIFO memory on DW QoS Eth and DW XGMAC */
+	if (priv->plat->has_gmac4 || priv->plat->has_xgmac) {
+		rxfifosz /= rx_channels_count;
+		txfifosz /= tx_channels_count;
+	}
 
 	if (priv->plat->force_thresh_dma_mode) {
 		txmode = tc;
@@ -2553,7 +2555,7 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
 				       true, priv->mode, true, true,
 				       xdp_desc.len);
 
-		stmmac_enable_dma_transmission(priv, priv->ioaddr);
+		stmmac_enable_dma_transmission(priv, priv->ioaddr, queue);
 
 		xsk_tx_metadata_to_compl(meta,
 					 &tx_q->tx_skbuff_dma[entry].xsk_meta);
@@ -4753,7 +4755,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	netdev_tx_sent_queue(netdev_get_tx_queue(dev, queue), skb->len);
 
-	stmmac_enable_dma_transmission(priv, priv->ioaddr);
+	stmmac_enable_dma_transmission(priv, priv->ioaddr, queue);
 
 	stmmac_flush_tx_descriptors(priv, queue);
 	stmmac_tx_timer_arm(priv, queue);
@@ -4980,7 +4982,7 @@ static int stmmac_xdp_xmit_xdpf(struct stmmac_priv *priv, int queue,
 		u64_stats_update_end(&txq_stats->q_syncp);
 	}
 
-	stmmac_enable_dma_transmission(priv, priv->ioaddr);
+	stmmac_enable_dma_transmission(priv, priv->ioaddr, queue);
 
 	entry = STMMAC_GET_ENTRY(entry, priv->dma_conf.dma_tx_size);
 	tx_q->cur_tx = entry;