Re: [bpf-next V2 PATCH 3/8] ixgbe: implement flush flag for ndo_xdp_xmit
From: Song Liu <hidden>
Date: 2018-05-31 16:14:31
On Thu, May 31, 2018 at 1:59 AM, Jesper Dangaard Brouer [off-list ref] wrote:
When passed the XDP_XMIT_FLUSH flag ixgbe_xdp_xmit now performs the same kind of ring tail update as in ixgbe_xdp_flush. The update tail code in ixgbe_xdp_flush is generalized and shared with ixgbe_xdp_xmit. Signed-off-by: Jesper Dangaard Brouer <redacted>
Acked-by: Song Liu <redacted>
quoted hunk ↗ jump to hunk
--- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 87f088f4af52..4fd77c9067f2 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c@@ -10022,6 +10022,15 @@ static int ixgbe_xdp(struct net_device *dev, struct netdev_bpf *xdp) } } +static void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring) +{ + /* Force memory writes to complete before letting h/w know there + * are new descriptors to fetch. + */ + wmb(); + writel(ring->next_to_use, ring->tail); +} + static int ixgbe_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, u32 flags) {@@ -10033,7 +10042,7 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state))) return -ENETDOWN; - if (unlikely(flags & ~XDP_XMIT_FLAGS_NONE)) + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) return -EINVAL; /* During program transitions its possible adapter->xdp_prog is assigned@@ -10054,6 +10063,9 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, } } + if (unlikely(flags & XDP_XMIT_FLUSH)) + ixgbe_xdp_ring_update_tail(ring); + return n - drops; }@@ -10072,11 +10084,7 @@ static void ixgbe_xdp_flush(struct net_device *dev) if (unlikely(!ring)) return; - /* Force memory writes to complete before letting h/w know there - * are new descriptors to fetch. - */ - wmb(); - writel(ring->next_to_use, ring->tail); + ixgbe_xdp_ring_update_tail(ring); return; }