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dpaa2-eth: Add basic XDP support
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We keep one XDP program reference per channel. The only actions
supported for now are XDP_DROP and XDP_PASS.

Until now we didn't enforce a maximum size for Rx frames based
on MTU value. Change that, since for XDP mode we must ensure no
scatter-gather frames can be received.

Signed-off-by: Ioana Radulescu <[email protected]>
Acked-by: Camelia Groza <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@davem330
Ioana Ciocoi Radulescu authored and davem330 committed Nov 28, 2018
1 parent 86d1d8b commit 7e273a8
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Showing 2 changed files with 194 additions and 1 deletion.
189 changes: 188 additions & 1 deletion drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,8 @@
#include <linux/iommu.h>
#include <linux/net_tstamp.h>
#include <linux/fsl/mc.h>

#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <net/sock.h>

#include "dpaa2-eth.h"
Expand Down Expand Up @@ -199,6 +200,45 @@ static struct sk_buff *build_frag_skb(struct dpaa2_eth_priv *priv,
return skb;
}

static u32 run_xdp(struct dpaa2_eth_priv *priv,
struct dpaa2_eth_channel *ch,
struct dpaa2_fd *fd, void *vaddr)
{
struct bpf_prog *xdp_prog;
struct xdp_buff xdp;
u32 xdp_act = XDP_PASS;

rcu_read_lock();

xdp_prog = READ_ONCE(ch->xdp.prog);
if (!xdp_prog)
goto out;

xdp.data = vaddr + dpaa2_fd_get_offset(fd);
xdp.data_end = xdp.data + dpaa2_fd_get_len(fd);
xdp.data_hard_start = xdp.data;
xdp_set_data_meta_invalid(&xdp);

xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);

switch (xdp_act) {
case XDP_PASS:
break;
default:
bpf_warn_invalid_xdp_action(xdp_act);
case XDP_ABORTED:
trace_xdp_exception(priv->net_dev, xdp_prog, xdp_act);
case XDP_DROP:
ch->buf_count--;
free_rx_fd(priv, fd, vaddr);
break;
}

out:
rcu_read_unlock();
return xdp_act;
}

/* Main Rx frame processing routine */
static void dpaa2_eth_rx(struct dpaa2_eth_priv *priv,
struct dpaa2_eth_channel *ch,
Expand All @@ -215,6 +255,7 @@ static void dpaa2_eth_rx(struct dpaa2_eth_priv *priv,
struct dpaa2_fas *fas;
void *buf_data;
u32 status = 0;
u32 xdp_act;

/* Tracing point */
trace_dpaa2_rx_fd(priv->net_dev, fd);
Expand All @@ -231,8 +272,17 @@ static void dpaa2_eth_rx(struct dpaa2_eth_priv *priv,
percpu_extras = this_cpu_ptr(priv->percpu_extras);

if (fd_format == dpaa2_fd_single) {
xdp_act = run_xdp(priv, ch, (struct dpaa2_fd *)fd, vaddr);
if (xdp_act != XDP_PASS) {
percpu_stats->rx_packets++;
percpu_stats->rx_bytes += dpaa2_fd_get_len(fd);
return;
}

skb = build_linear_skb(ch, fd, vaddr);
} else if (fd_format == dpaa2_fd_sg) {
WARN_ON(priv->xdp_prog);

skb = build_frag_skb(priv, ch, buf_data);
skb_free_frag(vaddr);
percpu_extras->rx_sg_frames++;
Expand Down Expand Up @@ -1427,6 +1477,141 @@ static int dpaa2_eth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
return -EINVAL;
}

static bool xdp_mtu_valid(struct dpaa2_eth_priv *priv, int mtu)
{
int mfl, linear_mfl;

mfl = DPAA2_ETH_L2_MAX_FRM(mtu);
linear_mfl = DPAA2_ETH_RX_BUF_SIZE - DPAA2_ETH_RX_HWA_SIZE -
dpaa2_eth_rx_head_room(priv);

if (mfl > linear_mfl) {
netdev_warn(priv->net_dev, "Maximum MTU for XDP is %d\n",
linear_mfl - VLAN_ETH_HLEN);
return false;
}

return true;
}

static int set_rx_mfl(struct dpaa2_eth_priv *priv, int mtu, bool has_xdp)
{
int mfl, err;

/* We enforce a maximum Rx frame length based on MTU only if we have
* an XDP program attached (in order to avoid Rx S/G frames).
* Otherwise, we accept all incoming frames as long as they are not
* larger than maximum size supported in hardware
*/
if (has_xdp)
mfl = DPAA2_ETH_L2_MAX_FRM(mtu);
else
mfl = DPAA2_ETH_MFL;

err = dpni_set_max_frame_length(priv->mc_io, 0, priv->mc_token, mfl);
if (err) {
netdev_err(priv->net_dev, "dpni_set_max_frame_length failed\n");
return err;
}

return 0;
}

static int dpaa2_eth_change_mtu(struct net_device *dev, int new_mtu)
{
struct dpaa2_eth_priv *priv = netdev_priv(dev);
int err;

if (!priv->xdp_prog)
goto out;

if (!xdp_mtu_valid(priv, new_mtu))
return -EINVAL;

err = set_rx_mfl(priv, new_mtu, true);
if (err)
return err;

out:
dev->mtu = new_mtu;
return 0;
}

static int setup_xdp(struct net_device *dev, struct bpf_prog *prog)
{
struct dpaa2_eth_priv *priv = netdev_priv(dev);
struct dpaa2_eth_channel *ch;
struct bpf_prog *old;
bool up, need_update;
int i, err;

if (prog && !xdp_mtu_valid(priv, dev->mtu))
return -EINVAL;

if (prog) {
prog = bpf_prog_add(prog, priv->num_channels);
if (IS_ERR(prog))
return PTR_ERR(prog);
}

up = netif_running(dev);
need_update = (!!priv->xdp_prog != !!prog);

if (up)
dpaa2_eth_stop(dev);

/* While in xdp mode, enforce a maximum Rx frame size based on MTU */
if (need_update) {
err = set_rx_mfl(priv, dev->mtu, !!prog);
if (err)
goto out_err;
}

old = xchg(&priv->xdp_prog, prog);
if (old)
bpf_prog_put(old);

for (i = 0; i < priv->num_channels; i++) {
ch = priv->channel[i];
old = xchg(&ch->xdp.prog, prog);
if (old)
bpf_prog_put(old);
}

if (up) {
err = dpaa2_eth_open(dev);
if (err)
return err;
}

return 0;

out_err:
if (prog)
bpf_prog_sub(prog, priv->num_channels);
if (up)
dpaa2_eth_open(dev);

return err;
}

static int dpaa2_eth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
struct dpaa2_eth_priv *priv = netdev_priv(dev);

switch (xdp->command) {
case XDP_SETUP_PROG:
return setup_xdp(dev, xdp->prog);
case XDP_QUERY_PROG:
xdp->prog_id = priv->xdp_prog ? priv->xdp_prog->aux->id : 0;
break;
default:
return -EINVAL;
}

return 0;
}

static const struct net_device_ops dpaa2_eth_ops = {
.ndo_open = dpaa2_eth_open,
.ndo_start_xmit = dpaa2_eth_tx,
Expand All @@ -1436,6 +1621,8 @@ static const struct net_device_ops dpaa2_eth_ops = {
.ndo_set_rx_mode = dpaa2_eth_set_rx_mode,
.ndo_set_features = dpaa2_eth_set_features,
.ndo_do_ioctl = dpaa2_eth_ioctl,
.ndo_change_mtu = dpaa2_eth_change_mtu,
.ndo_bpf = dpaa2_eth_xdp,
};

static void cdan_cb(struct dpaa2_io_notification_ctx *ctx)
Expand Down
6 changes: 6 additions & 0 deletions drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -283,6 +283,10 @@ struct dpaa2_eth_fq {
struct dpaa2_eth_fq_stats stats;
};

struct dpaa2_eth_ch_xdp {
struct bpf_prog *prog;
};

struct dpaa2_eth_channel {
struct dpaa2_io_notification_ctx nctx;
struct fsl_mc_device *dpcon;
Expand All @@ -294,6 +298,7 @@ struct dpaa2_eth_channel {
struct dpaa2_eth_priv *priv;
int buf_count;
struct dpaa2_eth_ch_stats stats;
struct dpaa2_eth_ch_xdp xdp;
};

struct dpaa2_eth_dist_fields {
Expand Down Expand Up @@ -353,6 +358,7 @@ struct dpaa2_eth_priv {
u64 rx_hash_fields;
struct dpaa2_eth_cls_rule *cls_rules;
u8 rx_cls_enabled;
struct bpf_prog *xdp_prog;
};

#define DPAA2_RXH_SUPPORTED (RXH_L2DA | RXH_VLAN | RXH_L3_PROTO \
Expand Down

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