net: stmmac: Add HW descriptor prefetch setting for DWMAC Core 5.20 onwards

DWMAC Core 5.20 onwards supports HW descriptor prefetching.
Additionally, it also depends on platform specific RTL configuration.
This capability could be enabled by setting DMA_Mode bit-19 (DCHE).

So, to enable this cability, platform must set plat->dma_cfg->dche = true
and the DWMAC core version must be 5.20 onwards. Else, this capability
wouldn`t be configured

Signed-off-by: Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index c54a56b..619e3c0 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/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
 

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index cb17f6c..a602d16 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/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,

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
index 05481eb..9321879 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
+++ b/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

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d1ca07c..372090e 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/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;

diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 97edb31..0db3636 100644 (file)
--- a/include/linux/stmmac.h
+++ b/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