Merge branch 'stmmac-swmac-desc-prefetch'

Mohammad Athari Bin Ismail says:

====================
Enable DWMAC HW descriptor prefetch

This patch series to add setting for HW descriptor prefetch for DWMAC
version 5.20 onwards. For Intel platform, enable the capability by
default.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -33,6 +33,7 @@
 #define DWMAC_CORE_4_10		0x41
 #define DWMAC_CORE_5_00		0x50
 #define DWMAC_CORE_5_10		0x51
+#define DWMAC_CORE_5_20		0x52
 #define DWXGMAC_CORE_2_10	0x21
 #define DWXLGMAC_CORE_2_00	0x20
 

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

@@ -471,6 +471,7 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 	plat->dma_cfg->fixed_burst = 0;
 	plat->dma_cfg->mixed_burst = 0;
 	plat->dma_cfg->aal = 0;
+	plat->dma_cfg->dche = true;
 
 	plat->axi = devm_kzalloc(&pdev->dev, sizeof(*plat->axi),
 				 GFP_KERNEL);

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

@@ -162,12 +162,18 @@ static void dwmac4_dma_init(void __iomem *ioaddr,
 
 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
 
+	value = readl(ioaddr + DMA_BUS_MODE);
+
 	if (dma_cfg->multi_msi_en) {
-		value = readl(ioaddr + DMA_BUS_MODE);
 		value &= ~DMA_BUS_MODE_INTM_MASK;
 		value |= (DMA_BUS_MODE_INTM_MODE1 << DMA_BUS_MODE_INTM_SHIFT);
-		writel(value, ioaddr + DMA_BUS_MODE);
 	}
+
+	if (dma_cfg->dche)
+		value |= DMA_BUS_MODE_DCHE;
+
+	writel(value, ioaddr + DMA_BUS_MODE);
+
 }
 
 static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel,

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

@@ -25,6 +25,7 @@
 #define DMA_TBS_CTRL			0x00001050
 
 /* DMA Bus Mode bitmap */
+#define DMA_BUS_MODE_DCHE		BIT(19)
 #define DMA_BUS_MODE_INTM_MASK		GENMASK(17, 16)
 #define DMA_BUS_MODE_INTM_SHIFT		16
 #define DMA_BUS_MODE_INTM_MODE1		0x1

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

@@ -6849,6 +6849,11 @@ int stmmac_dvr_probe(struct device *device,
 	if (ret)
 		goto error_hw_init;
 
+	/* Only DWMAC core version 5.20 onwards supports HW descriptor prefetch.
+	 */
+	if (priv->synopsys_id < DWMAC_CORE_5_20)
+		priv->plat->dma_cfg->dche = false;
+
 	stmmac_check_ether_addr(priv);
 
 	ndev->netdev_ops = &stmmac_netdev_ops;

include/linux/stmmac.h

@@ -97,6 +97,7 @@ struct stmmac_dma_cfg {
 	bool aal;
 	bool eame;
 	bool multi_msi_en;
+	bool dche;
 };
 
 #define AXI_BLEN	7