[dpdk-dev] [PATCH] net/ixgbevf: update VF_STAT macros to handle rollover

[Ye Xiaolong]

On 12/10, David Harton wrote:
>Added rollover logic to UPDATE_VF_STAT and UPDATE_VF_STAT_36BIT macros.
>
>Signed-off-by: David Harton <dharton at cisco.com>
>---
> drivers/net/ixgbe/ixgbe_ethdev.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
>index 49285ce53..bc73ad195 100644
>--- a/drivers/net/ixgbe/ixgbe_ethdev.c
>+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
>@@ -385,7 +385,11 @@ static void ixgbe_l2_tunnel_conf(struct rte_eth_dev *dev);
> #define UPDATE_VF_STAT(reg, last, cur)                          \
> {                                                               \
> 	uint32_t latest = IXGBE_READ_REG(hw, reg);              \
>-	cur += (latest - last) & UINT_MAX;                      \
>+	if (latest >= last)                                     \
>+		cur += (latest - last);                         \
>+	else                                                    \
>+		cur += ((latest + ((uint64_t)1 << 32)) - last); \
>+	cur &= UINT_MAX;                                        \
> 	last = latest;                                          \
> }
> 
>@@ -394,7 +398,11 @@ static void ixgbe_l2_tunnel_conf(struct rte_eth_dev *dev);
> 	u64 new_lsb = IXGBE_READ_REG(hw, lsb);                   \
> 	u64 new_msb = IXGBE_READ_REG(hw, msb);                   \
> 	u64 latest = ((new_msb << 32) | new_lsb);                \
>-	cur += (0x1000000000LL + latest - last) & 0xFFFFFFFFFLL; \
>+	if (latest >= last)                                      \
>+		cur += (latest - last);                          \
>+	else                                                     \
>+		cur += ((latest + ((u64)1 << 36)) - last);       \
>+	cur &= 0xFFFFFFFFFLL;                                    \
> 	last = latest;                                           \
> }
> 
>-- 
>2.19.1
>o

Could you provide Fixes: tag and cc stable?

Acked-by: Xiaolong Ye <xiaolong.ye at intel.com>