diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index cf18940..0d6af19 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -145,13 +145,14 @@ config MDIO_GPIO
 	  will be called mdio-gpio.
 
 config MDIO_OCTEON
-	tristate "Support for MDIO buses on Octeon SOCs"
-	depends on CAVIUM_OCTEON_SOC
+	tristate "Support for MDIO buses on Octeon and ThunderX SOCs"
+	depends on 64BIT
 	default y
 	help
 
-	  This module provides a driver for the Octeon MDIO busses.
-	  It is required by the Octeon Ethernet device drivers.
+	  This module provides a driver for the Octeon and ThunderX MDIO
+	  busses. It is required by the Octeon and ThunderX ethernet device
+	  drivers.
 
 	  If in doubt, say Y.
 
diff --git a/drivers/net/phy/mdio-octeon.c b/drivers/net/phy/mdio-octeon.c
index c838ad6..507aade 100644
--- a/drivers/net/phy/mdio-octeon.c
+++ b/drivers/net/phy/mdio-octeon.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/platform_device.h>
+#include <linux/of_address.h>
 #include <linux/of_mdio.h>
 #include <linux/delay.h>
 #include <linux/module.h>
@@ -14,11 +15,12 @@
 #include <linux/phy.h>
 #include <linux/io.h>
 
+#ifdef CONFIG_CAVIUM_OCTEON_SOC
 #include <asm/octeon/octeon.h>
-#include <asm/octeon/cvmx-smix-defs.h>
+#endif
 
-#define DRV_VERSION "1.0"
-#define DRV_DESCRIPTION "Cavium Networks Octeon SMI/MDIO driver"
+#define DRV_VERSION "1.1"
+#define DRV_DESCRIPTION "Cavium Networks Octeon/ThunderX SMI/MDIO driver"
 
 #define SMI_CMD		0x0
 #define SMI_WR_DAT	0x8
@@ -26,6 +28,79 @@
 #define SMI_CLK		0x18
 #define SMI_EN		0x20
 
+#ifdef __BIG_ENDIAN_BITFIELD
+#define OCT_MDIO_BITFIELD_FIELD(field, more)	\
+	field;					\
+	more
+
+#else
+#define OCT_MDIO_BITFIELD_FIELD(field, more)	\
+	more					\
+	field;
+
+#endif
+
+union cvmx_smix_clk {
+	uint64_t u64;
+	struct cvmx_smix_clk_s {
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_25_63:39,
+	  OCT_MDIO_BITFIELD_FIELD(u64 mode:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_21_23:3,
+	  OCT_MDIO_BITFIELD_FIELD(u64 sample_hi:5,
+	  OCT_MDIO_BITFIELD_FIELD(u64 sample_mode:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_14_14:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 clk_idle:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 preamble:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 sample:4,
+	  OCT_MDIO_BITFIELD_FIELD(u64 phase:8,
+	  ;))))))))))
+	} s;
+};
+
+union cvmx_smix_cmd {
+	uint64_t u64;
+	struct cvmx_smix_cmd_s {
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_18_63:46,
+	  OCT_MDIO_BITFIELD_FIELD(u64 phy_op:2,
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_13_15:3,
+	  OCT_MDIO_BITFIELD_FIELD(u64 phy_adr:5,
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_5_7:3,
+	  OCT_MDIO_BITFIELD_FIELD(u64 reg_adr:5,
+	  ;))))))
+	} s;
+};
+
+union cvmx_smix_en {
+	uint64_t u64;
+	struct cvmx_smix_en_s {
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_1_63:63,
+	  OCT_MDIO_BITFIELD_FIELD(u64 en:1,
+	  ;))
+	} s;
+};
+
+union cvmx_smix_rd_dat {
+	uint64_t u64;
+	struct cvmx_smix_rd_dat_s {
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_18_63:46,
+	  OCT_MDIO_BITFIELD_FIELD(u64 pending:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 val:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 dat:16,
+	  ;))))
+	} s;
+};
+
+union cvmx_smix_wr_dat {
+	uint64_t u64;
+	struct cvmx_smix_wr_dat_s {
+	  OCT_MDIO_BITFIELD_FIELD(u64 reserved_18_63:46,
+	  OCT_MDIO_BITFIELD_FIELD(u64 pending:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 val:1,
+	  OCT_MDIO_BITFIELD_FIELD(u64 dat:16,
+	  ;))))
+	} s;
+};
+
 enum octeon_mdiobus_mode {
 	UNINIT = 0,
 	C22,
@@ -41,6 +116,21 @@ struct octeon_mdiobus {
 	int phy_irq[PHY_MAX_ADDR];
 };
 
+#ifdef CONFIG_CAVIUM_OCTEON_SOC
+static void oct_mdio_writeq(u64 val, u64 addr)
+{
+	cvmx_write_csr(addr, val);
+}
+
+static u64 oct_mdio_readq(u64 addr)
+{
+	return cvmx_read_csr(addr);
+}
+#else
+#define oct_mdio_writeq(val, addr)	writeq_relaxed(val, (void *)addr)
+#define oct_mdio_readq(addr)		readq_relaxed((void *)addr)
+#endif
+
 static void octeon_mdiobus_set_mode(struct octeon_mdiobus *p,
 				    enum octeon_mdiobus_mode m)
 {
@@ -49,10 +139,10 @@ static void octeon_mdiobus_set_mode(struct octeon_mdiobus *p,
 	if (m == p->mode)
 		return;
 
-	smi_clk.u64 = cvmx_read_csr(p->register_base + SMI_CLK);
+	smi_clk.u64 = oct_mdio_readq(p->register_base + SMI_CLK);
 	smi_clk.s.mode = (m == C45) ? 1 : 0;
 	smi_clk.s.preamble = 1;
-	cvmx_write_csr(p->register_base + SMI_CLK, smi_clk.u64);
+	oct_mdio_writeq(smi_clk.u64, p->register_base + SMI_CLK);
 	p->mode = m;
 }
 
@@ -67,7 +157,7 @@ static int octeon_mdiobus_c45_addr(struct octeon_mdiobus *p,
 
 	smi_wr.u64 = 0;
 	smi_wr.s.dat = regnum & 0xffff;
-	cvmx_write_csr(p->register_base + SMI_WR_DAT, smi_wr.u64);
+	oct_mdio_writeq(smi_wr.u64, p->register_base + SMI_WR_DAT);
 
 	regnum = (regnum >> 16) & 0x1f;
 
@@ -75,14 +165,14 @@ static int octeon_mdiobus_c45_addr(struct octeon_mdiobus *p,
 	smi_cmd.s.phy_op = 0; /* MDIO_CLAUSE_45_ADDRESS */
 	smi_cmd.s.phy_adr = phy_id;
 	smi_cmd.s.reg_adr = regnum;
-	cvmx_write_csr(p->register_base + SMI_CMD, smi_cmd.u64);
+	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
 
 	do {
 		/* Wait 1000 clocks so we don't saturate the RSL bus
 		 * doing reads.
 		 */
 		__delay(1000);
-		smi_wr.u64 = cvmx_read_csr(p->register_base + SMI_WR_DAT);
+		smi_wr.u64 = oct_mdio_readq(p->register_base + SMI_WR_DAT);
 	} while (smi_wr.s.pending && --timeout);
 
 	if (timeout <= 0)
@@ -114,14 +204,14 @@ static int octeon_mdiobus_read(struct mii_bus *bus, int phy_id, int regnum)
 	smi_cmd.s.phy_op = op;
 	smi_cmd.s.phy_adr = phy_id;
 	smi_cmd.s.reg_adr = regnum;
-	cvmx_write_csr(p->register_base + SMI_CMD, smi_cmd.u64);
+	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
 
 	do {
 		/* Wait 1000 clocks so we don't saturate the RSL bus
 		 * doing reads.
 		 */
 		__delay(1000);
-		smi_rd.u64 = cvmx_read_csr(p->register_base + SMI_RD_DAT);
+		smi_rd.u64 = oct_mdio_readq(p->register_base + SMI_RD_DAT);
 	} while (smi_rd.s.pending && --timeout);
 
 	if (smi_rd.s.val)
@@ -153,20 +243,20 @@ static int octeon_mdiobus_write(struct mii_bus *bus, int phy_id,
 
 	smi_wr.u64 = 0;
 	smi_wr.s.dat = val;
-	cvmx_write_csr(p->register_base + SMI_WR_DAT, smi_wr.u64);
+	oct_mdio_writeq(smi_wr.u64, p->register_base + SMI_WR_DAT);
 
 	smi_cmd.u64 = 0;
 	smi_cmd.s.phy_op = op;
 	smi_cmd.s.phy_adr = phy_id;
 	smi_cmd.s.reg_adr = regnum;
-	cvmx_write_csr(p->register_base + SMI_CMD, smi_cmd.u64);
+	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
 
 	do {
 		/* Wait 1000 clocks so we don't saturate the RSL bus
 		 * doing reads.
 		 */
 		__delay(1000);
-		smi_wr.u64 = cvmx_read_csr(p->register_base + SMI_WR_DAT);
+		smi_wr.u64 = oct_mdio_readq(p->register_base + SMI_WR_DAT);
 	} while (smi_wr.s.pending && --timeout);
 
 	if (timeout <= 0)
@@ -210,7 +300,7 @@ static int octeon_mdiobus_probe(struct platform_device *pdev)
 
 	smi_en.u64 = 0;
 	smi_en.s.en = 1;
-	cvmx_write_csr(bus->register_base + SMI_EN, smi_en.u64);
+	oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN);
 
 	bus->mii_bus->priv = bus;
 	bus->mii_bus->irq = bus->phy_irq;
@@ -234,7 +324,7 @@ fail_register:
 	mdiobus_free(bus->mii_bus);
 fail:
 	smi_en.u64 = 0;
-	cvmx_write_csr(bus->register_base + SMI_EN, smi_en.u64);
+	oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN);
 	return err;
 }
 
@@ -248,7 +338,7 @@ static int octeon_mdiobus_remove(struct platform_device *pdev)
 	mdiobus_unregister(bus->mii_bus);
 	mdiobus_free(bus->mii_bus);
 	smi_en.u64 = 0;
-	cvmx_write_csr(bus->register_base + SMI_EN, smi_en.u64);
+	oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN);
 	return 0;
 }
 
