ac746c8520
The previous stmmac_xdp_set_prog() implementation uses stmmac_release()
and stmmac_open() which tear down the PHY device and causes undesirable
autonegotiation which causes a delay whenever AFXDP ZC is setup.
This patch introduces two new functions that just sufficiently tear
down DMA descriptors, buffer, NAPI process, and IRQs and reestablish
them accordingly in both stmmac_xdp_release() and stammac_xdp_open().
As the results of this enhancement, we get rid of transient state
introduced by the link auto-negotiation:
$ ./xdpsock -i eth0 -t -z
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 634444 634560
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 632330 1267072
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 632438 1899584
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 632502 2532160
Reported-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
135 lines
3.2 KiB
C
135 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2021, Intel Corporation. */
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#include <net/xdp_sock_drv.h>
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#include "stmmac.h"
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#include "stmmac_xdp.h"
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static int stmmac_xdp_enable_pool(struct stmmac_priv *priv,
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struct xsk_buff_pool *pool, u16 queue)
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{
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struct stmmac_channel *ch = &priv->channel[queue];
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bool need_update;
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u32 frame_size;
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int err;
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if (queue >= priv->plat->rx_queues_to_use ||
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queue >= priv->plat->tx_queues_to_use)
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return -EINVAL;
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frame_size = xsk_pool_get_rx_frame_size(pool);
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/* XDP ZC does not span multiple frame, make sure XSK pool buffer
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* size can at least store Q-in-Q frame.
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*/
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if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2)
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return -EOPNOTSUPP;
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err = xsk_pool_dma_map(pool, priv->device, STMMAC_RX_DMA_ATTR);
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if (err) {
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netdev_err(priv->dev, "Failed to map xsk pool\n");
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return err;
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}
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need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
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if (need_update) {
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napi_disable(&ch->rx_napi);
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napi_disable(&ch->tx_napi);
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stmmac_disable_rx_queue(priv, queue);
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stmmac_disable_tx_queue(priv, queue);
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}
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set_bit(queue, priv->af_xdp_zc_qps);
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if (need_update) {
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stmmac_enable_rx_queue(priv, queue);
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stmmac_enable_tx_queue(priv, queue);
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napi_enable(&ch->rxtx_napi);
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err = stmmac_xsk_wakeup(priv->dev, queue, XDP_WAKEUP_RX);
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if (err)
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return err;
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}
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return 0;
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}
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static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
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{
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struct stmmac_channel *ch = &priv->channel[queue];
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struct xsk_buff_pool *pool;
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bool need_update;
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if (queue >= priv->plat->rx_queues_to_use ||
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queue >= priv->plat->tx_queues_to_use)
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return -EINVAL;
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pool = xsk_get_pool_from_qid(priv->dev, queue);
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if (!pool)
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return -EINVAL;
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need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
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if (need_update) {
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napi_disable(&ch->rxtx_napi);
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stmmac_disable_rx_queue(priv, queue);
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stmmac_disable_tx_queue(priv, queue);
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synchronize_rcu();
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}
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xsk_pool_dma_unmap(pool, STMMAC_RX_DMA_ATTR);
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clear_bit(queue, priv->af_xdp_zc_qps);
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if (need_update) {
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stmmac_enable_rx_queue(priv, queue);
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stmmac_enable_tx_queue(priv, queue);
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napi_enable(&ch->rx_napi);
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napi_enable(&ch->tx_napi);
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}
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return 0;
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}
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int stmmac_xdp_setup_pool(struct stmmac_priv *priv, struct xsk_buff_pool *pool,
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u16 queue)
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{
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return pool ? stmmac_xdp_enable_pool(priv, pool, queue) :
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stmmac_xdp_disable_pool(priv, queue);
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}
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int stmmac_xdp_set_prog(struct stmmac_priv *priv, struct bpf_prog *prog,
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struct netlink_ext_ack *extack)
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{
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struct net_device *dev = priv->dev;
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struct bpf_prog *old_prog;
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bool need_update;
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bool if_running;
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if_running = netif_running(dev);
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if (prog && dev->mtu > ETH_DATA_LEN) {
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/* For now, the driver doesn't support XDP functionality with
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* jumbo frames so we return error.
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*/
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NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
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return -EOPNOTSUPP;
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}
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need_update = !!priv->xdp_prog != !!prog;
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if (if_running && need_update)
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stmmac_xdp_release(dev);
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old_prog = xchg(&priv->xdp_prog, prog);
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if (old_prog)
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bpf_prog_put(old_prog);
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/* Disable RX SPH for XDP operation */
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priv->sph = priv->sph_cap && !stmmac_xdp_is_enabled(priv);
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if (if_running && need_update)
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stmmac_xdp_open(dev);
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return 0;
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}
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