[PATCH] net: sparx5: fix bitmask check

From: Arnd Bergmann
Date: Mon Aug 02 2021 - 10:54:57 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

Older compilers such as gcc-5.5 produce a warning in this driver
when ifh_encode_bitfield() is not getting inlined:

drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c: In function 'ifh_encode_bitfield':
include/linux/compiler_types.h:333:38: error: call to '__compiletime_assert_545' declared with attribute error: Unsupported width, must be <= 40
drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c:28:2: note: in expansion of macro 'compiletime_assert'
compiletime_assert(width <= 40, "Unsupported width, must be <= 40");
^

Mark the function as __always_inline to make the check work correctly
on all compilers. To make this also work on 32-bit architectures, change
the GENMASK() to GENMASK_ULL().

Fixes: f3cad2611a77 ("net: sparx5: add hostmode with phylink support")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c b/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c
index 9d485a9d1f1f..6f362f6708c6 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c
@@ -13,14 +13,15 @@
*/
#define VSTAX 73

-static void ifh_encode_bitfield(void *ifh, u64 value, u32 pos, u32 width)
+static __always_inline void ifh_encode_bitfield(void *ifh, u64 value,
+ u32 pos, u32 width)
{
u8 *ifh_hdr = ifh;
/* Calculate the Start IFH byte position of this IFH bit position */
u32 byte = (35 - (pos / 8));
/* Calculate the Start bit position in the Start IFH byte */
u32 bit = (pos % 8);
- u64 encode = GENMASK(bit + width - 1, bit) & (value << bit);
+ u64 encode = GENMASK_ULL(bit + width - 1, bit) & (value << bit);

/* Max width is 5 bytes - 40 bits. In worst case this will
* spread over 6 bytes - 48 bits
--
2.29.2