[PATCH v3 1/1] net: fec: add initial XDP support
From: Shenwei Wang
Date: Mon Oct 31 2022 - 14:54:20 EST
This patch adds the initial XDP support to Freescale driver. It supports
XDP_PASS, XDP_DROP and XDP_REDIRECT actions. Upcoming patches will add
support for XDP_TX and Zero Copy features.
As the patch is rather large, the part of codes to collect the
statistics is separated and will prepare a dedicated patch for that
part.
I just tested with the application of xdpsock.
-- Native here means running command of "xdpsock -i eth0"
-- SKB-Mode means running command of "xdpsock -S -i eth0"
The following are the testing result relating to XDP mode:
root@imx8qxpc0mek:~/bpf# ./xdpsock -i eth0
sock0@eth0:0 rxdrop xdp-drv
pps pkts 1.00
rx 371347 2717794
tx 0 0
root@imx8qxpc0mek:~/bpf# ./xdpsock -S -i eth0
sock0@eth0:0 rxdrop xdp-skb
pps pkts 1.00
rx 202229 404528
tx 0 0
root@imx8qxpc0mek:~/bpf# ./xdp2 eth0
proto 0: 496708 pkt/s
proto 0: 505469 pkt/s
proto 0: 505283 pkt/s
proto 0: 505443 pkt/s
proto 0: 505465 pkt/s
root@imx8qxpc0mek:~/bpf# ./xdp2 -S eth0
proto 0: 0 pkt/s
proto 17: 118778 pkt/s
proto 17: 118989 pkt/s
proto 0: 1 pkt/s
proto 17: 118987 pkt/s
proto 0: 0 pkt/s
proto 17: 118943 pkt/s
proto 17: 118976 pkt/s
proto 0: 1 pkt/s
proto 17: 119006 pkt/s
proto 0: 0 pkt/s
proto 17: 119071 pkt/s
proto 17: 119092 pkt/s
Signed-off-by: Shenwei Wang <shenwei.wang@xxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
changes in V3:
- remove the codes to update the RX ring size to avoid potential risk.
- update the testing data based on the new implementation.
changes in V2:
- Get rid of the expensive fec_net_close/open function calls during
XDP/Normal Mode switch.
- Update the testing data on i.mx8qxp mek board.
- fix the compile issue reported by kernel_test_robot
drivers/net/ethernet/freescale/fec.h | 4 +-
drivers/net/ethernet/freescale/fec_main.c | 224 +++++++++++++++++++++-
2 files changed, 226 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 476e3863a310..61e847b18343 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -348,7 +348,6 @@ struct bufdesc_ex {
*/
#define FEC_ENET_XDP_HEADROOM (XDP_PACKET_HEADROOM)
-
#define FEC_ENET_RX_PAGES 256
#define FEC_ENET_RX_FRSIZE (PAGE_SIZE - FEC_ENET_XDP_HEADROOM \
- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
@@ -663,6 +662,9 @@ struct fec_enet_private {
struct imx_sc_ipc *ipc_handle;
+ /* XDP BPF Program */
+ struct bpf_prog *xdp_prog;
+
u64 ethtool_stats[];
};
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 6986b74fb8af..6b062a0663f4 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -89,6 +89,11 @@ static const u16 fec_enet_vlan_pri_to_queue[8] = {0, 0, 1, 1, 1, 2, 2, 2};
#define FEC_ENET_OPD_V 0xFFF0
#define FEC_MDIO_PM_TIMEOUT 100 /* ms */
+#define FEC_ENET_XDP_PASS 0
+#define FEC_ENET_XDP_CONSUMED BIT(0)
+#define FEC_ENET_XDP_TX BIT(1)
+#define FEC_ENET_XDP_REDIR BIT(2)
+
struct fec_devinfo {
u32 quirks;
};
@@ -418,13 +423,14 @@ static int
fec_enet_create_page_pool(struct fec_enet_private *fep,
struct fec_enet_priv_rx_q *rxq, int size)
{
+ struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
struct page_pool_params pp_params = {
.order = 0,
.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
.pool_size = size,
.nid = dev_to_node(&fep->pdev->dev),
.dev = &fep->pdev->dev,
- .dma_dir = DMA_FROM_DEVICE,
+ .dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
.offset = FEC_ENET_XDP_HEADROOM,
.max_len = FEC_ENET_RX_FRSIZE,
};
@@ -1499,6 +1505,59 @@ static void fec_enet_update_cbd(struct fec_enet_priv_rx_q *rxq,
bdp->cbd_bufaddr = cpu_to_fec32(phys_addr);
}
+static u32
+fec_enet_run_xdp(struct fec_enet_private *fep, struct bpf_prog *prog,
+ struct xdp_buff *xdp, struct fec_enet_priv_rx_q *rxq, int index)
+{
+ unsigned int sync, len = xdp->data_end - xdp->data;
+ u32 ret = FEC_ENET_XDP_PASS;
+ struct page *page;
+ int err;
+ u32 act;
+
+ act = bpf_prog_run_xdp(prog, xdp);
+
+ /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */
+ sync = xdp->data_end - xdp->data_hard_start - FEC_ENET_XDP_HEADROOM;
+ sync = max(sync, len);
+
+ switch (act) {
+ case XDP_PASS:
+ ret = FEC_ENET_XDP_PASS;
+ break;
+
+ case XDP_REDIRECT:
+ err = xdp_do_redirect(fep->netdev, xdp, prog);
+ if (!err) {
+ ret = FEC_ENET_XDP_REDIR;
+ } else {
+ ret = FEC_ENET_XDP_CONSUMED;
+ page = virt_to_head_page(xdp->data);
+ page_pool_put_page(rxq->page_pool, page, sync, true);
+ }
+ break;
+
+ default:
+ bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
+ fallthrough;
+
+ case XDP_TX:
+ bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
+ fallthrough;
+
+ case XDP_ABORTED:
+ fallthrough; /* handle aborts by dropping packet */
+
+ case XDP_DROP:
+ ret = FEC_ENET_XDP_CONSUMED;
+ page = virt_to_head_page(xdp->data);
+ page_pool_put_page(rxq->page_pool, page, sync, true);
+ break;
+ }
+
+ return ret;
+}
+
/* During a receive, the bd_rx.cur points to the current incoming buffer.
* When we update through the ring, if the next incoming buffer has
* not been given to the system, we just set the empty indicator,
@@ -1520,6 +1579,9 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
u16 vlan_tag;
int index = 0;
bool need_swap = fep->quirks & FEC_QUIRK_SWAP_FRAME;
+ struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
+ u32 ret, xdp_result = FEC_ENET_XDP_PASS;
+ struct xdp_buff xdp;
struct page *page;
#ifdef CONFIG_M532x
@@ -1531,6 +1593,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
* These get messed up if we get called due to a busy condition.
*/
bdp = rxq->bd.cur;
+ xdp_init_buff(&xdp, PAGE_SIZE, &rxq->xdp_rxq);
while (!((status = fec16_to_cpu(bdp->cbd_sc)) & BD_ENET_RX_EMPTY)) {
@@ -1580,6 +1643,17 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
prefetch(page_address(page));
fec_enet_update_cbd(rxq, bdp, index);
+ if (xdp_prog) {
+ xdp_buff_clear_frags_flag(&xdp);
+ xdp_prepare_buff(&xdp, page_address(page),
+ FEC_ENET_XDP_HEADROOM, pkt_len, false);
+
+ ret = fec_enet_run_xdp(fep, xdp_prog, &xdp, rxq, index);
+ xdp_result |= ret;
+ if (ret != FEC_ENET_XDP_PASS)
+ goto rx_processing_done;
+ }
+
/* The packet length includes FCS, but we don't want to
* include that when passing upstream as it messes up
* bridging applications.
@@ -1675,6 +1749,10 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
writel(0, rxq->bd.reg_desc_active);
}
rxq->bd.cur = bdp;
+
+ if (xdp_result & FEC_ENET_XDP_REDIR)
+ xdp_do_flush_map();
+
return pkt_received;
}
@@ -3476,6 +3554,148 @@ static u16 fec_enet_select_queue(struct net_device *ndev, struct sk_buff *skb,
return fec_enet_vlan_pri_to_queue[vlan_tag >> 13];
}
+static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
+{
+ struct fec_enet_private *fep = netdev_priv(dev);
+ bool is_run = netif_running(dev);
+ struct bpf_prog *old_prog;
+
+ switch (bpf->command) {
+ case XDP_SETUP_PROG:
+ if (is_run) {
+ napi_disable(&fep->napi);
+ netif_tx_disable(dev);
+ }
+
+ old_prog = xchg(&fep->xdp_prog, bpf->prog);
+ fec_restart(dev);
+
+ if (is_run) {
+ napi_enable(&fep->napi);
+ netif_tx_start_all_queues(dev);
+ }
+
+ if (old_prog)
+ bpf_prog_put(old_prog);
+
+ return 0;
+
+ case XDP_SETUP_XSK_POOL:
+ return -EOPNOTSUPP;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int
+fec_enet_xdp_get_tx_queue(struct fec_enet_private *fep, int cpu)
+{
+ int index = cpu;
+
+ if (unlikely(index < 0))
+ index = 0;
+
+ while (index >= fep->num_tx_queues)
+ index -= fep->num_tx_queues;
+
+ return index;
+}
+
+static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
+ struct fec_enet_priv_tx_q *txq,
+ struct xdp_frame *frame)
+{
+ unsigned int index, status, estatus;
+ struct bufdesc *bdp, *last_bdp;
+ dma_addr_t dma_addr;
+ int entries_free;
+
+ entries_free = fec_enet_get_free_txdesc_num(txq);
+ if (entries_free < MAX_SKB_FRAGS + 1) {
+ netdev_err(fep->netdev, "NOT enough BD for SG!\n");
+ return NETDEV_TX_OK;
+ }
+
+ /* Fill in a Tx ring entry */
+ bdp = txq->bd.cur;
+ last_bdp = bdp;
+ status = fec16_to_cpu(bdp->cbd_sc);
+ status &= ~BD_ENET_TX_STATS;
+
+ index = fec_enet_get_bd_index(bdp, &txq->bd);
+
+ dma_addr = dma_map_single(&fep->pdev->dev, frame->data,
+ frame->len, DMA_TO_DEVICE);
+ if (dma_mapping_error(&fep->pdev->dev, dma_addr))
+ return FEC_ENET_XDP_CONSUMED;
+
+ status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
+ if (fep->bufdesc_ex)
+ estatus = BD_ENET_TX_INT;
+
+ bdp->cbd_bufaddr = cpu_to_fec32(dma_addr);
+ bdp->cbd_datlen = cpu_to_fec16(frame->len);
+
+ if (fep->bufdesc_ex) {
+ struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
+
+ if (fep->quirks & FEC_QUIRK_HAS_AVB)
+ estatus |= FEC_TX_BD_FTYPE(txq->bd.qid);
+
+ ebdp->cbd_bdu = 0;
+ ebdp->cbd_esc = cpu_to_fec32(estatus);
+ }
+
+ index = fec_enet_get_bd_index(last_bdp, &txq->bd);
+ txq->tx_skbuff[index] = NULL;
+
+ /* Send it on its way. Tell FEC it's ready, interrupt when done,
+ * it's the last BD of the frame, and to put the CRC on the end.
+ */
+ status |= (BD_ENET_TX_READY | BD_ENET_TX_TC);
+ bdp->cbd_sc = cpu_to_fec16(status);
+
+ /* If this was the last BD in the ring, start at the beginning again. */
+ bdp = fec_enet_get_nextdesc(last_bdp, &txq->bd);
+
+ txq->bd.cur = bdp;
+
+ return 0;
+}
+
+static int fec_enet_xdp_xmit(struct net_device *dev,
+ int num_frames,
+ struct xdp_frame **frames,
+ u32 flags)
+{
+ struct fec_enet_private *fep = netdev_priv(dev);
+ struct fec_enet_priv_tx_q *txq;
+ int cpu = smp_processor_id();
+ struct netdev_queue *nq;
+ unsigned int queue;
+ int i;
+
+ queue = fec_enet_xdp_get_tx_queue(fep, cpu);
+ txq = fep->tx_queue[queue];
+ nq = netdev_get_tx_queue(fep->netdev, queue);
+
+ __netif_tx_lock(nq, cpu);
+
+ for (i = 0; i < num_frames; i++)
+ fec_enet_txq_xmit_frame(fep, txq, frames[i]);
+
+ /* Make sure the update to bdp and tx_skbuff are performed. */
+ wmb();
+
+ /* Trigger transmission start */
+ writel(0, txq->bd.reg_desc_active);
+
+ __netif_tx_unlock(nq);
+
+ return num_frames;
+}
+
static const struct net_device_ops fec_netdev_ops = {
.ndo_open = fec_enet_open,
.ndo_stop = fec_enet_close,
@@ -3490,6 +3710,8 @@ static const struct net_device_ops fec_netdev_ops = {
.ndo_poll_controller = fec_poll_controller,
#endif
.ndo_set_features = fec_set_features,
+ .ndo_bpf = fec_enet_bpf,
+ .ndo_xdp_xmit = fec_enet_xdp_xmit,
};
static const unsigned short offset_des_active_rxq[] = {
--
2.34.1