idpf: implement XDP_SETUP_PROG in ndo_bpf for splitq

Implement loading/removing XDP program using .ndo_bpf callback
in the split queue mode. Reconfigure and restart the queues if needed
(!!old_prog != !!new_prog), otherwise, just update the pointers.

Signed-off-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Tested-by: Ramu R <ramu.r@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/idpf/idpf_lib.c

@@ -2614,4 +2614,5 @@ static const struct net_device_ops idpf_netdev_ops = {
 	.ndo_tx_timeout = idpf_tx_timeout,
 	.ndo_hwtstamp_get = idpf_hwtstamp_get,
 	.ndo_hwtstamp_set = idpf_hwtstamp_set,
+	.ndo_bpf = idpf_xdp,
 };

drivers/net/ethernet/intel/idpf/idpf_txrx.c

@@ -762,6 +762,8 @@ int idpf_rx_bufs_init_all(struct idpf_vport *vport)
 	bool split = idpf_is_queue_model_split(vport->rxq_model);
 	int i, j, err;
 
+	idpf_xdp_copy_prog_to_rqs(vport, vport->xdp_prog);
+
 	for (i = 0; i < vport->num_rxq_grp; i++) {
 		struct idpf_rxq_group *rx_qgrp = &vport->rxq_grps[i];
 		u32 truesize = 0;
@@ -1040,6 +1042,8 @@ static void idpf_vport_queue_grp_rel_all(struct idpf_vport *vport)
  */
 void idpf_vport_queues_rel(struct idpf_vport *vport)
 {
+	idpf_xdp_copy_prog_to_rqs(vport, NULL);
+
 	idpf_tx_desc_rel_all(vport);
 	idpf_rx_desc_rel_all(vport);
 

drivers/net/ethernet/intel/idpf/idpf_txrx.h

@@ -467,6 +467,7 @@ struct idpf_tx_queue_stats {
  * @desc_ring: virtual descriptor ring address
  * @bufq_sets: Pointer to the array of buffer queues in splitq mode
  * @napi: NAPI instance corresponding to this queue (splitq)
+ * @xdp_prog: attached XDP program
  * @rx_buf: See struct &libeth_fqe
  * @pp: Page pool pointer in singleq mode
  * @tail: Tail offset. Used for both queue models single and split.
@@ -508,13 +509,14 @@ struct idpf_rx_queue {
 		struct {
 			struct idpf_bufq_set *bufq_sets;
 			struct napi_struct *napi;
+			struct bpf_prog __rcu *xdp_prog;
 		};
 		struct {
 			struct libeth_fqe *rx_buf;
 			struct page_pool *pp;
+			void __iomem *tail;
 		};
 	};
-	void __iomem *tail;
 
 	DECLARE_BITMAP(flags, __IDPF_Q_FLAGS_NBITS);
 	u16 idx;

drivers/net/ethernet/intel/idpf/xdp.c

@@ -4,6 +4,7 @@
 #include <net/libeth/xdp.h>
 
 #include "idpf.h"
+#include "idpf_virtchnl.h"
 #include "xdp.h"
 
 static int idpf_rxq_for_each(const struct idpf_vport *vport,
@@ -91,6 +92,27 @@ void idpf_xdp_rxq_info_deinit_all(const struct idpf_vport *vport)
 			  (void *)(size_t)vport->rxq_model);
 }
 
+static int idpf_xdp_rxq_assign_prog(struct idpf_rx_queue *rxq, void *arg)
+{
+	struct bpf_prog *prog = arg;
+	struct bpf_prog *old;
+
+	if (prog)
+		bpf_prog_inc(prog);
+
+	old = rcu_replace_pointer(rxq->xdp_prog, prog, lockdep_rtnl_is_held());
+	if (old)
+		bpf_prog_put(old);
+
+	return 0;
+}
+
+void idpf_xdp_copy_prog_to_rqs(const struct idpf_vport *vport,
+			       struct bpf_prog *xdp_prog)
+{
+	idpf_rxq_for_each(vport, idpf_xdp_rxq_assign_prog, xdp_prog);
+}
+
 int idpf_xdpsqs_get(const struct idpf_vport *vport)
 {
 	struct libeth_xdpsq_timer **timers __free(kvfree) = NULL;
@@ -166,3 +188,78 @@ void idpf_xdpsqs_put(const struct idpf_vport *vport)
 		idpf_queue_clear(NOIRQ, xdpsq);
 	}
 }
+
+static int idpf_xdp_setup_prog(struct idpf_vport *vport,
+			       const struct netdev_bpf *xdp)
+{
+	const struct idpf_netdev_priv *np = netdev_priv(vport->netdev);
+	struct bpf_prog *old, *prog = xdp->prog;
+	struct idpf_vport_config *cfg;
+	int ret;
+
+	cfg = vport->adapter->vport_config[vport->idx];
+
+	if (test_bit(IDPF_REMOVE_IN_PROG, vport->adapter->flags) ||
+	    !test_bit(IDPF_VPORT_REG_NETDEV, cfg->flags) ||
+	    !!vport->xdp_prog == !!prog) {
+		if (np->state == __IDPF_VPORT_UP)
+			idpf_xdp_copy_prog_to_rqs(vport, prog);
+
+		old = xchg(&vport->xdp_prog, prog);
+		if (old)
+			bpf_prog_put(old);
+
+		cfg->user_config.xdp_prog = prog;
+
+		return 0;
+	}
+
+	if (!vport->num_xdp_txq && vport->num_txq == cfg->max_q.max_txq) {
+		NL_SET_ERR_MSG_MOD(xdp->extack,
+				   "No Tx queues available for XDP, please decrease the number of regular SQs");
+		return -ENOSPC;
+	}
+
+	old = cfg->user_config.xdp_prog;
+	cfg->user_config.xdp_prog = prog;
+
+	ret = idpf_initiate_soft_reset(vport, IDPF_SR_Q_CHANGE);
+	if (ret) {
+		NL_SET_ERR_MSG_MOD(xdp->extack,
+				   "Could not reopen the vport after XDP setup");
+
+		cfg->user_config.xdp_prog = old;
+		old = prog;
+	}
+
+	if (old)
+		bpf_prog_put(old);
+
+	return ret;
+}
+
+int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+	struct idpf_vport *vport;
+	int ret;
+
+	idpf_vport_ctrl_lock(dev);
+	vport = idpf_netdev_to_vport(dev);
+
+	if (!idpf_is_queue_model_split(vport->txq_model))
+		goto notsupp;
+
+	switch (xdp->command) {
+	case XDP_SETUP_PROG:
+		ret = idpf_xdp_setup_prog(vport, xdp);
+		break;
+	default:
+notsupp:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	idpf_vport_ctrl_unlock(dev);
+
+	return ret;
+}

drivers/net/ethernet/intel/idpf/xdp.h

@@ -6,12 +6,19 @@
 
 #include <linux/types.h>
 
+struct bpf_prog;
 struct idpf_vport;
+struct net_device;
+struct netdev_bpf;
 
 int idpf_xdp_rxq_info_init_all(const struct idpf_vport *vport);
 void idpf_xdp_rxq_info_deinit_all(const struct idpf_vport *vport);
+void idpf_xdp_copy_prog_to_rqs(const struct idpf_vport *vport,
+			       struct bpf_prog *xdp_prog);
 
 int idpf_xdpsqs_get(const struct idpf_vport *vport);
 void idpf_xdpsqs_put(const struct idpf_vport *vport);
 
+int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp);
+
 #endif /* _IDPF_XDP_H_ */