net: stmmac: Adjust dump offset of DMA registers for ethtool

The commit fbf68229 ("net: stmmac: unify registers dumps methods")

in the Linux kernel modified the register dump to store the DMA registers
at the DMA register offset (0x1000) but ethtool (stmmac.c) looks for the
DMA registers after the MAC registers which is offset 55.
This patch copies the DMA registers from the higher offset to the offset
where ethtool expects them.
Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -205,7 +205,7 @@ static void dwmac1000_dump_dma_regs(void __iomem *ioaddr, u32 *reg_space)
 {
 	int i;
 
-	for (i = 0; i < 23; i++)
+	for (i = 0; i < NUM_DWMAC1000_DMA_REGS; i++)
 		if ((i < 12) || (i > 17))
 			reg_space[DMA_BUS_MODE / 4 + i] =
 				readl(ioaddr + DMA_BUS_MODE + i * 4);

drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c

@@ -70,7 +70,7 @@ static void dwmac100_dump_dma_regs(void __iomem *ioaddr, u32 *reg_space)
 {
 	int i;
 
-	for (i = 0; i < 9; i++)
+	for (i = 0; i < NUM_DWMAC100_DMA_REGS; i++)
 		reg_space[DMA_BUS_MODE / 4 + i] =
 			readl(ioaddr + DMA_BUS_MODE + i * 4);
 

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

@@ -136,6 +136,9 @@
 #define DMA_STATUS_TI	0x00000001	/* Transmit Interrupt */
 #define DMA_CONTROL_FTF		0x00100000	/* Flush transmit FIFO */
 
+#define NUM_DWMAC100_DMA_REGS	9
+#define NUM_DWMAC1000_DMA_REGS	23
+
 void dwmac_enable_dma_transmission(void __iomem *ioaddr);
 void dwmac_enable_dma_irq(void __iomem *ioaddr, u32 chan);
 void dwmac_disable_dma_irq(void __iomem *ioaddr, u32 chan);

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

@@ -33,6 +33,8 @@
 #define MAC100_ETHTOOL_NAME	"st_mac100"
 #define GMAC_ETHTOOL_NAME	"st_gmac"
 
+#define ETHTOOL_DMA_OFFSET	55
+
 struct stmmac_stats {
 	char stat_string[ETH_GSTRING_LEN];
 	int sizeof_stat;
@@ -442,6 +444,9 @@ static void stmmac_ethtool_gregs(struct net_device *dev,
 
 	priv->hw->mac->dump_regs(priv->hw, reg_space);
 	priv->hw->dma->dump_regs(priv->ioaddr, reg_space);
+	/* Copy DMA registers to where ethtool expects them */
+	memcpy(&reg_space[ETHTOOL_DMA_OFFSET], &reg_space[DMA_BUS_MODE / 4],
+	       NUM_DWMAC1000_DMA_REGS * 4);
 }
 
 static void