From: Jesper Dangaard Brouer Date: Tue, 21 Mar 2023 13:52:31 +0000 (+0100) Subject: xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver support X-Git-Tag: v6.6.17~5262^2^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=915efd8a446b74442039d31689d5d863caf82517;p=platform%2Fkernel%2Flinux-rpi.git xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver support When driver doesn't implement a bpf_xdp_metadata kfunc the fallback implementation returns EOPNOTSUPP, which indicate device driver doesn't implement this kfunc. Currently many drivers also return EOPNOTSUPP when the hint isn't available, which is ambiguous from an API point of view. Instead change drivers to return ENODATA in these cases. There can be natural cases why a driver doesn't provide any hardware info for a specific hint, even on a frame to frame basis (e.g. PTP). Lets keep these cases as separate return codes. When describing the return values, adjust the function kernel-doc layout to get proper rendering for the return values. Fixes: ab46182d0dcb ("net/mlx4_en: Support RX XDP metadata") Fixes: bc8d405b1ba9 ("net/mlx5e: Support RX XDP metadata") Fixes: 306531f0249f ("veth: Support RX XDP metadata") Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Jesper Dangaard Brouer Acked-by: Stanislav Fomichev Acked-by: Toke Høiland-Jørgensen Acked-by: Tariq Toukan Link: https://lore.kernel.org/r/167940675120.2718408.8176058626864184420.stgit@firesoul Signed-off-by: Alexei Starovoitov --- diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst index aac63fc..25ce72a 100644 --- a/Documentation/networking/xdp-rx-metadata.rst +++ b/Documentation/networking/xdp-rx-metadata.rst @@ -23,10 +23,13 @@ metadata is supported, this set will grow: An XDP program can use these kfuncs to read the metadata into stack variables for its own consumption. Or, to pass the metadata on to other consumers, an XDP program can store it into the metadata area carried -ahead of the packet. +ahead of the packet. Not all packets will necessary have the requested +metadata available in which case the driver returns ``-ENODATA``. Not all kfuncs have to be implemented by the device driver; when not -implemented, the default ones that return ``-EOPNOTSUPP`` will be used. +implemented, the default ones that return ``-EOPNOTSUPP`` will be used +to indicate the device driver have not implemented this kfunc. + Within an XDP frame, the metadata layout (accessed via ``xdp_buff``) is as follows:: diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 0869d4f..4b5e459 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -674,7 +674,7 @@ int mlx4_en_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp) struct mlx4_en_xdp_buff *_ctx = (void *)ctx; if (unlikely(_ctx->ring->hwtstamp_rx_filter != HWTSTAMP_FILTER_ALL)) - return -EOPNOTSUPP; + return -ENODATA; *timestamp = mlx4_en_get_hwtstamp(_ctx->mdev, mlx4_en_get_cqe_ts(_ctx->cqe)); @@ -686,7 +686,7 @@ int mlx4_en_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash) struct mlx4_en_xdp_buff *_ctx = (void *)ctx; if (unlikely(!(_ctx->dev->features & NETIF_F_RXHASH))) - return -EOPNOTSUPP; + return -ENODATA; *hash = be32_to_cpu(_ctx->cqe->immed_rss_invalid); return 0; diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c index bcd6370d..c5dae48 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c @@ -162,7 +162,7 @@ static int mlx5e_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp) const struct mlx5e_xdp_buff *_ctx = (void *)ctx; if (unlikely(!mlx5e_rx_hw_stamp(_ctx->rq->tstamp))) - return -EOPNOTSUPP; + return -ENODATA; *timestamp = mlx5e_cqe_ts_to_ns(_ctx->rq->ptp_cyc2time, _ctx->rq->clock, get_cqe_ts(_ctx->cqe)); @@ -174,7 +174,7 @@ static int mlx5e_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash) const struct mlx5e_xdp_buff *_ctx = (void *)ctx; if (unlikely(!(_ctx->xdp.rxq->dev->features & NETIF_F_RXHASH))) - return -EOPNOTSUPP; + return -ENODATA; *hash = be32_to_cpu(_ctx->cqe->rss_hash_result); return 0; diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 1bb54de..046461e 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -1610,7 +1610,7 @@ static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp) struct veth_xdp_buff *_ctx = (void *)ctx; if (!_ctx->skb) - return -EOPNOTSUPP; + return -ENODATA; *timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp; return 0; @@ -1621,7 +1621,7 @@ static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash) struct veth_xdp_buff *_ctx = (void *)ctx; if (!_ctx->skb) - return -EOPNOTSUPP; + return -ENODATA; *hash = skb_get_hash(_ctx->skb); return 0; diff --git a/net/core/xdp.c b/net/core/xdp.c index 8c92fc5..2477971 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -720,7 +720,10 @@ __diag_ignore_all("-Wmissing-prototypes", * @ctx: XDP context pointer. * @timestamp: Return value pointer. * - * Returns 0 on success or ``-errno`` on error. + * Return: + * * Returns 0 on success or ``-errno`` on error. + * * ``-EOPNOTSUPP`` : means device driver does not implement kfunc + * * ``-ENODATA`` : means no RX-timestamp available for this frame */ __bpf_kfunc int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp) { @@ -732,7 +735,10 @@ __bpf_kfunc int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *tim * @ctx: XDP context pointer. * @hash: Return value pointer. * - * Returns 0 on success or ``-errno`` on error. + * Return: + * * Returns 0 on success or ``-errno`` on error. + * * ``-EOPNOTSUPP`` : means device driver doesn't implement kfunc + * * ``-ENODATA`` : means no RX-hash available for this frame */ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash) {