net: xilinx: axi_emac: Fix dma descriptors for 64bit and compilation warnings

There are compilation warnings showing up when we compile AXI ethernet
driver for 64bit architectures. Fix them, so that it works on both 32
and 64 bit architectures.

DMA descriptors are not taking care of 64bit addresses. To fix it,
change axidma_bd members as below:

next		==>	next_desc
reserverd1	==>	next_desc_msb
phys		==>	buf_addr
reserverd2	==>	buf_addr_msb

and update next_desc and buf_addr with lower 32 bits of the addresses,
update next_desc_msb and buf_addr_msb with upper 32 bits of the 64bit
addresses.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/drivers/net/xilinx_axi_emac.c b/drivers/net/xilinx_axi_emac.c
index 99d4d85..c56c4d0 100644
--- a/drivers/net/xilinx_axi_emac.c
+++ b/drivers/net/xilinx_axi_emac.c
@@ -101,10 +101,10 @@
 
 /* BD descriptors */
 struct axidma_bd {
-	u32 next;	/* Next descriptor pointer */
-	u32 reserved1;
-	u32 phys;	/* Buffer address */
-	u32 reserved2;
+	u32 next_desc;	/* Next descriptor pointer */
+	u32 next_desc_msb;
+	u32 buf_addr;	/* Buffer address */
+	u32 buf_addr_msb;
 	u32 reserved3;
 	u32 reserved4;
 	u32 cntrl;	/* Control */
@@ -182,7 +182,7 @@
 static inline void axienet_dma_write(struct axidma_bd *bd, u32 *desc)
 {
 #if defined(CONFIG_PHYS_64BIT)
-	writeq(bd, desc);
+	writeq((unsigned long)bd, desc);
 #else
 	writel((u32)bd, desc);
 #endif
@@ -492,8 +492,12 @@
 
 	/* Setup the BD. */
 	memset(&rx_bd, 0, sizeof(rx_bd));
-	rx_bd.next = (u32)&rx_bd;
-	rx_bd.phys = (u32)&rxframe;
+	rx_bd.next_desc = lower_32_bits((unsigned long)&rx_bd);
+	rx_bd.buf_addr = lower_32_bits((unsigned long)&rxframe);
+#if defined(CONFIG_PHYS_64BIT)
+	rx_bd.next_desc_msb = upper_32_bits((unsigned long)&rx_bd);
+	rx_bd.buf_addr_msb = upper_32_bits((unsigned long)&rxframe);
+#endif
 	rx_bd.cntrl = sizeof(rxframe);
 	/* Flush the last BD so DMA core could see the updates */
 	flush_cache((u32)&rx_bd, sizeof(rx_bd));
@@ -539,8 +543,12 @@
 	/* Setup Tx BD */
 	memset(&tx_bd, 0, sizeof(tx_bd));
 	/* At the end of the ring, link the last BD back to the top */
-	tx_bd.next = (u32)&tx_bd;
-	tx_bd.phys = (u32)ptr;
+	tx_bd.next_desc = lower_32_bits((unsigned long)&tx_bd);
+	tx_bd.buf_addr = lower_32_bits((unsigned long)ptr);
+#if defined(CONFIG_PHYS_64BIT)
+	tx_bd.next_desc_msb = upper_32_bits((unsigned long)&tx_bd);
+	tx_bd.buf_addr_msb = upper_32_bits((unsigned long)ptr);
+#endif
 	/* Save len */
 	tx_bd.cntrl = len | XAXIDMA_BD_CTRL_TXSOF_MASK |
 						XAXIDMA_BD_CTRL_TXEOF_MASK;
@@ -637,8 +645,12 @@
 	/* Setup RxBD */
 	/* Clear the whole buffer and setup it again - all flags are cleared */
 	memset(&rx_bd, 0, sizeof(rx_bd));
-	rx_bd.next = (u32)&rx_bd;
-	rx_bd.phys = (u32)&rxframe;
+	rx_bd.next_desc = lower_32_bits((unsigned long)&rx_bd);
+	rx_bd.buf_addr = lower_32_bits((unsigned long)&rxframe);
+#if defined(CONFIG_PHYS_64BIT)
+	rx_bd.next_desc_msb = upper_32_bits((unsigned long)&rx_bd);
+	rx_bd.buf_addr_msb = upper_32_bits((unsigned long)&rxframe);
+#endif
 	rx_bd.cntrl = sizeof(rxframe);
 
 	/* Write bd to HW */
@@ -738,7 +750,7 @@
 		return -EINVAL;
 	}
 	/* RX channel offset is 0x30 */
-	priv->dmarx = (struct axidma_reg *)((u32)priv->dmatx + 0x30);
+	priv->dmarx = (struct axidma_reg *)((phys_addr_t)priv->dmatx + 0x30);
 
 	priv->phyaddr = -1;