[PATCH] net: mdio-octeon: Fix build error and Kconfig warning

[Nathan Chancellor <natechancellor@gmail.com>]

arm allyesconfig warns:

WARNING: unmet direct dependencies detected for MDIO_OCTEON
  Depends on [n]: NETDEVICES [=y] && MDIO_DEVICE [=y] && MDIO_BUS [=y]
&& 64BIT && HAS_IOMEM [=y] && OF_MDIO [=y]
  Selected by [y]:
  - OCTEON_ETHERNET [=y] && STAGING [=y] && (CAVIUM_OCTEON_SOC &&
NETDEVICES [=y] || COMPILE_TEST [=y])

and errors:

In file included from ../drivers/net/phy/mdio-octeon.c:14:
../drivers/net/phy/mdio-octeon.c: In function 'octeon_mdiobus_probe':
../drivers/net/phy/mdio-cavium.h:111:36: error: implicit declaration of
function 'writeq'; did you mean 'writeb'?
[-Werror=implicit-function-declaration]
  111 | #define oct_mdio_writeq(val, addr) writeq(val, (void *)addr)
      |                                    ^~~~~~
../drivers/net/phy/mdio-octeon.c:56:2: note: in expansion of macro
'oct_mdio_writeq'
   56 |  oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN);
      |  ^~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

This allows MDIO_OCTEON to be built with COMPILE_TEST as well and
includes the proper header for readq/writeq. This does not address
the several -Wint-to-pointer-cast and -Wpointer-to-int-cast warnings
that appeared as a result of commit 171a9bae68c7 ("staging/octeon:
Allow test build on !MIPS") in these files.

Fixes: 171a9bae68c7 ("staging/octeon: Allow test build on !MIPS")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Mark Brown <broonie@kernel.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 drivers/net/phy/Kconfig       | 2 +-
 drivers/net/phy/mdio-cavium.h | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 20f14c5fbb7e..ed2edf4b5b0e 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -159,7 +159,7 @@ config MDIO_MSCC_MIIM
 
 config MDIO_OCTEON
 	tristate "Octeon and some ThunderX SOCs MDIO buses"
-	depends on 64BIT
+	depends on 64BIT || COMPILE_TEST
 	depends on HAS_IOMEM && OF_MDIO
 	select MDIO_CAVIUM
 	help
diff --git a/drivers/net/phy/mdio-cavium.h b/drivers/net/phy/mdio-cavium.h
index ed5f9bb5448d..b7f89ad27465 100644
--- a/drivers/net/phy/mdio-cavium.h
+++ b/drivers/net/phy/mdio-cavium.h
@@ -108,6 +108,8 @@ static inline u64 oct_mdio_readq(u64 addr)
 	return cvmx_read_csr(addr);
 }
 #else
+#include <linux/io-64-nonatomic-lo-hi.h>
+
 #define oct_mdio_writeq(val, addr)	writeq(val, (void *)addr)
 #define oct_mdio_readq(addr)		readq((void *)addr)
 #endif
-- 
2.22.0