[PATCH net-next 6/8] dpaa2-eth: Add support for XDP_TX

[Ioana Ciocoi Radulescu]

Send frames back on the same port for XDP_TX action.
Since the frame buffers have been allocated by us, we can recycle
them directly into the Rx buffer pool instead of requesting a
confirmation frame upon transmission complete.

Signed-off-by: Ioana Radulescu <ruxandra.radule...@nxp.com>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 43 +++++++++++++++++++++++-
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h |  2 ++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c 
b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index 1bdcd71..3dabee0 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -240,14 +240,50 @@ static void xdp_release_buf(struct dpaa2_eth_priv *priv,
        ch->xdp.drop_cnt = 0;
 }
 
+static int xdp_enqueue(struct dpaa2_eth_priv *priv, struct dpaa2_fd *fd,
+                      void *buf_start, u16 queue_id)
+{
+       struct dpaa2_eth_fq *fq;
+       struct dpaa2_faead *faead;
+       u32 ctrl, frc;
+       int i, err;
+
+       /* Mark the egress frame hardware annotation area as valid */
+       frc = dpaa2_fd_get_frc(fd);
+       dpaa2_fd_set_frc(fd, frc | DPAA2_FD_FRC_FAEADV);
+       dpaa2_fd_set_ctrl(fd, DPAA2_FD_CTRL_ASAL);
+
+       /* Instruct hardware to release the FD buffer directly into
+        * the buffer pool once transmission is completed, instead of
+        * sending a Tx confirmation frame to us
+        */
+       ctrl = DPAA2_FAEAD_A4V | DPAA2_FAEAD_A2V | DPAA2_FAEAD_EBDDV;
+       faead = dpaa2_get_faead(buf_start, false);
+       faead->ctrl = cpu_to_le32(ctrl);
+       faead->conf_fqid = 0;
+
+       fq = &priv->fq[queue_id];
+       for (i = 0; i < DPAA2_ETH_ENQUEUE_RETRIES; i++) {
+               err = dpaa2_io_service_enqueue_qd(fq->channel->dpio,
+                                                 priv->tx_qdid, 0,
+                                                 fq->tx_qdbin, fd);
+               if (err != -EBUSY)
+                       break;
+       }
+
+       return err;
+}
+
 static u32 run_xdp(struct dpaa2_eth_priv *priv,
                   struct dpaa2_eth_channel *ch,
+                  struct dpaa2_eth_fq *rx_fq,
                   struct dpaa2_fd *fd, void *vaddr)
 {
        dma_addr_t addr = dpaa2_fd_get_addr(fd);
        struct bpf_prog *xdp_prog;
        struct xdp_buff xdp;
        u32 xdp_act = XDP_PASS;
+       int err;
 
        rcu_read_lock();
 
@@ -269,6 +305,11 @@ static u32 run_xdp(struct dpaa2_eth_priv *priv,
        switch (xdp_act) {
        case XDP_PASS:
                break;
+       case XDP_TX:
+               err = xdp_enqueue(priv, fd, vaddr, rx_fq->flowid);
+               if (err)
+                       xdp_release_buf(priv, ch, addr);
+               break;
        default:
                bpf_warn_invalid_xdp_action(xdp_act);
        case XDP_ABORTED:
@@ -317,7 +358,7 @@ 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);
+               xdp_act = run_xdp(priv, ch, fq, (struct dpaa2_fd *)fd, vaddr);
                if (xdp_act != XDP_PASS)
                        return;
 
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h 
b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
index 23cf9d9..5530a0e 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
@@ -139,7 +139,9 @@ struct dpaa2_faead {
 };
 
 #define DPAA2_FAEAD_A2V                        0x20000000
+#define DPAA2_FAEAD_A4V                        0x08000000
 #define DPAA2_FAEAD_UPDV               0x00001000
+#define DPAA2_FAEAD_EBDDV              0x00002000
 #define DPAA2_FAEAD_UPD                        0x00000010
 
 /* Accessors for the hardware annotation fields that we use */
-- 
2.7.4