On Thu, 2020-11-12 at 20:10 +0200, Camelia Groza wrote:
> Implement the XDP_DROP and XDP_PASS actions.
>
> Avoid draining and reconfiguring the buffer pool at each XDP
> setup/teardown by increasing the frame headroom and reserving
> XDP_PACKET_HEADROOM bytes from the start. Since we always reserve an
> entire page per buffer, this change only impacts Jumbo frame
> scenarios
> where the maximum linear frame size is reduced by 256 bytes. Multi
> buffer Scatter/Gather frames are now used instead in these scenarios.
>
> Allow XDP programs to access the entire buffer.
>
> The data in the received frame's headroom can be overwritten by the
> XDP
> program. Extract the relevant fields from the headroom while they are
> still available, before running the XDP program.
>
> Since the headroom might be resized before the frame is passed up to
> the
> stack, remove the check for a fixed headroom value when building an
> skb.
>
> Allow the meta data to be updated and pass the information up the
> stack.
>
> Signed-off-by: Camelia Groza <camelia.gr...@nxp.com>
> ---
> drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 148
> ++++++++++++++++++++++---
> drivers/net/ethernet/freescale/dpaa/dpaa_eth.h | 2 +
> 2 files changed, 134 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> index 88533a2..d1d8a46 100644
> --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> @@ -53,6 +53,8 @@
> #include <linux/dma-mapping.h>
> #include <linux/sort.h>
> #include <linux/phy_fixed.h>
> +#include <linux/bpf.h>
> +#include <linux/bpf_trace.h>
> #include <soc/fsl/bman.h>
> #include <soc/fsl/qman.h>
> #include "fman.h"
> @@ -177,7 +179,7 @@
> #define DPAA_HWA_SIZE (DPAA_PARSE_RESULTS_SIZE +
> DPAA_TIME_STAMP_SIZE \
> + DPAA_HASH_RESULTS_SIZE)
> #define DPAA_RX_PRIV_DATA_DEFAULT_SIZE (DPAA_TX_PRIV_DATA_SIZE + \
> - dpaa_rx_extra_headroom)
> + XDP_PACKET_HEADROOM -
> DPAA_HWA_SIZE)
> #ifdef CONFIG_DPAA_ERRATUM_A050385
> #define DPAA_RX_PRIV_DATA_A050385_SIZE (DPAA_A050385_ALIGN -
> DPAA_HWA_SIZE)
> #define DPAA_RX_PRIV_DATA_SIZE (fman_has_errata_a050385() ? \
> @@ -1733,7 +1735,6 @@ static struct sk_buff *contig_fd_to_skb(const
> struct dpaa_priv *priv,
> SKB_DATA_ALIGN(sizeof(struct
> skb_shared_info)));
> if (WARN_ONCE(!skb, "Build skb failure on Rx\n"))
> goto free_buffer;
> - WARN_ON(fd_off != priv->rx_headroom);
> skb_reserve(skb, fd_off);
> skb_put(skb, qm_fd_get_length(fd));
>
> @@ -2349,12 +2350,62 @@ static enum qman_cb_dqrr_result
> rx_error_dqrr(struct qman_portal *portal,
> return qman_cb_dqrr_consume;
> }
>
> +static u32 dpaa_run_xdp(struct dpaa_priv *priv, struct qm_fd *fd,
> void *vaddr,
> + unsigned int *xdp_meta_len)
> +{
> + ssize_t fd_off = qm_fd_get_offset(fd);
> + struct bpf_prog *xdp_prog;
> + struct xdp_buff xdp;
> + u32 xdp_act;
> +
> + rcu_read_lock();
> +
> + xdp_prog = READ_ONCE(priv->xdp_prog);
> + if (!xdp_prog) {
> + rcu_read_unlock();
> + return XDP_PASS;
> + }
> +
> + xdp.data = vaddr + fd_off;
> + xdp.data_meta = xdp.data;
> + xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM;
> + xdp.data_end = xdp.data + qm_fd_get_length(fd);
> + xdp.frame_sz = DPAA_BP_RAW_SIZE;
> +
> + xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);
> +
> + /* Update the length and the offset of the FD */
> + qm_fd_set_contig(fd, xdp.data - vaddr, xdp.data_end -
> xdp.data);
> +
> + switch (xdp_act) {
> + case XDP_PASS:
> + *xdp_meta_len = xdp.data - xdp.data_meta;
> + break;
> + default:
> + bpf_warn_invalid_xdp_action(xdp_act);
> + fallthrough;
> + case XDP_ABORTED:
> + trace_xdp_exception(priv->net_dev, xdp_prog, xdp_act);
> + fallthrough;
> + case XDP_DROP:
> + /* Free the buffer */
> + free_pages((unsigned long)vaddr, 0);
> + break;
> + }
> +
> + rcu_read_unlock();
> +
> + return xdp_act;
> +}
> +
> static enum qman_cb_dqrr_result rx_default_dqrr(struct qman_portal
> *portal,
> struct qman_fq *fq,
> const struct
> qm_dqrr_entry *dq,
> bool sched_napi)
> {
> + bool ts_valid = false, hash_valid = false;
> struct skb_shared_hwtstamps *shhwtstamps;
> + unsigned int skb_len, xdp_meta_len = 0;
> struct rtnl_link_stats64 *percpu_stats;
> struct dpaa_percpu_priv *percpu_priv;
> const struct qm_fd *fd = &dq->fd;
> @@ -2364,10 +2415,11 @@ static enum qman_cb_dqrr_result
> rx_default_dqrr(struct qman_portal *portal,
> u32 fd_status, hash_offset;
> struct dpaa_bp *dpaa_bp;
> struct dpaa_priv *priv;
> - unsigned int skb_len;
> struct sk_buff *skb;
> int *count_ptr;
> + u32 xdp_act;
> void *vaddr;
> + u32 hash;
> u64 ns;
>
> fd_status = be32_to_cpu(fd->status);
> @@ -2423,35 +2475,58 @@ static enum qman_cb_dqrr_result
> rx_default_dqrr(struct qman_portal *portal,
> count_ptr = this_cpu_ptr(dpaa_bp->percpu_count);
> (*count_ptr)--;
>
> - if (likely(fd_format == qm_fd_contig))
> + /* Extract the timestamp stored in the headroom before running
> XDP */
> + if (priv->rx_tstamp) {
> + if (!fman_port_get_tstamp(priv->mac_dev->port[RX],
> vaddr, &ns))
> + ts_valid = true;
> + else
> + dev_warn(net_dev->dev.parent,
> "fman_port_get_tstamp failed!\n");
dev_warn per packet is a bad idea.. you might want to change this to
WARN_ONCE() or a counter.
> + }
> +
> + /* Extract the hash stored in the headroom before running XDP
> */
> + if (net_dev->features & NETIF_F_RXHASH && priv->keygen_in_use
> &&
> + !fman_port_get_hash_result_offset(priv->mac_dev->port[RX],
> + &hash_offset)) {
> + hash = be32_to_cpu(*(u32 *)(vaddr + hash_offset));
> + hash_valid = true;
> + }
> +
I hope you keep this data avaialbe in the headroom buffer on
extraction..
Soon enough XDP programs will have the means to see the headroom meta
data from the NIC.
https://zabiplane.groups.io/g/dev/message/56
Latest discussion on making NIC timestamp available to XDP programs.
https://www.spinics.net/lists/netdev/msg699281.html
> + if (likely(fd_format == qm_fd_contig)) {
> + xdp_act = dpaa_run_xdp(priv, (struct qm_fd *)fd, vaddr,
> + &xdp_meta_len);
> + if (xdp_act != XDP_PASS) {
> + percpu_stats->rx_packets++;
> + percpu_stats->rx_bytes += qm_fd_get_length(fd);
> + return qman_cb_dqrr_consume;
> + }
> skb = contig_fd_to_skb(priv, fd);
> - else
> + } else {
> + WARN_ONCE(priv->xdp_prog, "S/G frames not supported
> under XDP\n");
> skb = sg_fd_to_skb(priv, fd);
> + }
> if (!skb)
> return qman_cb_dqrr_consume;
>
> - if (priv->rx_tstamp) {
> + if (xdp_meta_len)
> + skb_metadata_set(skb, xdp_meta_len);
> +
> + /* Set the previously extracted timestamp */
> + if (ts_valid) {
> shhwtstamps = skb_hwtstamps(skb);
> memset(shhwtstamps, 0, sizeof(*shhwtstamps));
> -
> - if (!fman_port_get_tstamp(priv->mac_dev->port[RX],
> vaddr, &ns))
> - shhwtstamps->hwtstamp = ns_to_ktime(ns);
> - else
> - dev_warn(net_dev->dev.parent,
> "fman_port_get_tstamp failed!\n");
> + shhwtstamps->hwtstamp = ns_to_ktime(ns);
> }
>
> skb->protocol = eth_type_trans(skb, net_dev);
>
> - if (net_dev->features & NETIF_F_RXHASH && priv->keygen_in_use
> &&
> - !fman_port_get_hash_result_offset(priv->mac_dev->port[RX],
> - &hash_offset)) {
> + /* Set the previously extracted hash */
> + if (hash_valid) {
> enum pkt_hash_types type;
>
> /* if L4 exists, it was used in the hash generation */
> type = be32_to_cpu(fd->status) & FM_FD_STAT_L4CV ?
> PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3;
> - skb_set_hash(skb, be32_to_cpu(*(u32 *)(vaddr +
> hash_offset)),
> - type);
> + skb_set_hash(skb, hash, type);
> }
>
