[PATCH net-next v4 07/13] net: mana: swap queue sets in mana_xdp_set

@@ -177,6 +177,8 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog,
 			struct netlink_ext_ack *extack)
 {
 	struct mana_port_context *apc = netdev_priv(ndev);
+	struct mana_port_context *scratch;
+	struct mana_qset newq, oldq;
 	struct bpf_prog *old_prog;
 	struct gdma_context *gc;
 	int err;

@@ -196,46 +198,44 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog,
 		return -EOPNOTSUPP;
 	}
 
-	/* One refcnt of the prog is hold by the caller already, so
-	 * don't increase refcnt for this one.
-	 */
-	apc->bpf_prog = prog;
-
 	if (apc->port_is_up) {
-		/* Re-create rxq's after xdp prog was loaded or unloaded.
-		 * Ex: re create rxq's to switch from full pages to smaller
-		 * size page fragments when xdp prog is unloaded and
-		 * vice-versa.
-		 */
-
-		/* Pre-allocate buffers to prevent failure in mana_attach */
-		err = mana_pre_alloc_rxbufs(apc, ndev->mtu, apc->num_queues);
-		if (err) {
+		scratch = mana_qset_scratch_alloc(apc);
+		if (!scratch) {
 			NL_SET_ERR_MSG_MOD(extack,
-					   "XDP: Insufficient memory for tx/rx re-config");
-			return err;
+					   "XDP: Insufficient memory for re-config");
+			return -ENOMEM;
 		}
 
-		err = mana_detach(ndev, false);
+		err = mana_alloc_qset(apc, scratch, apc->num_queues,
+				      apc->rx_queue_size, apc->tx_queue_size,
+				      apc->priv_flags, apc->configured_mtu,
+				      prog, &newq);
 		if (err) {
-			netdev_err(ndev,
-				   "mana_detach failed at xdp set: %d\n", err);
 			NL_SET_ERR_MSG_MOD(extack,
-					   "XDP: Re-config failed at detach");
-			goto err_dealloc_rxbuffs;
+					   "XDP: Re-config failed at alloc");
+			mana_qset_scratch_free(scratch);
+			return err;
 		}
 
-		err = mana_attach(ndev);
+		err = mana_publish_qset(apc, &newq, &oldq);
 		if (err) {
-			netdev_err(ndev,
-				   "mana_attach failed at xdp set: %d\n", err);
 			NL_SET_ERR_MSG_MOD(extack,
-					   "XDP: Re-config failed at attach");
-			goto err_dealloc_rxbuffs;
+					   "XDP: Re-config failed at publish");
+			mana_free_qset(scratch, &newq);
+			/* Free the queues before closing their shared EQ pool.
+			 */
+			mana_publish_close_if_needed(apc);
+			mana_qset_scratch_free(scratch);
+			return err;
 		}
 
-		mana_chn_setxdp(apc, prog);
-		mana_pre_dealloc_rxbufs(apc);
+		mana_free_qset(scratch, &oldq);
+		mana_qset_scratch_free(scratch);
+	} else {
+		/* Use the caller's program reference; mana_open() installs it
+		 * on queues.
+		 */
+		apc->bpf_prog = prog;
 	}
 
 	if (old_prog)

@@ -248,11 +248,6 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog,
 		ndev->max_mtu = gc->adapter_mtu - ETH_HLEN;
 
 	return 0;
-
-err_dealloc_rxbuffs:
-	apc->bpf_prog = old_prog;
-	mana_pre_dealloc_rxbufs(apc);
-	return err;
 }
 
 int mana_bpf(struct net_device *ndev, struct netdev_bpf *bpf)

@@ -916,9 +916,9 @@ static int mana_change_mtu(struct net_device *ndev, int new_mtu)
 	if (!scratch)
 		return -ENOMEM;
 
-	err = mana_alloc_qset(mpc, scratch, mpc->num_queues,
-			      mpc->rx_queue_size, mpc->tx_queue_size,
-			      mpc->priv_flags, new_mtu, &newq);
+	err = mana_alloc_qset(mpc, scratch, mpc->num_queues, mpc->rx_queue_size,
+			      mpc->tx_queue_size, mpc->priv_flags, new_mtu,
+			      mpc->bpf_prog, &newq);
 	if (err)
 		goto free_scratch;
 

@@ -3916,6 +3916,7 @@ static void mana_qset_snapshot(const struct mana_port_context *ctx,
 	out->tx_queue_size	= ctx->tx_queue_size;
 	out->priv_flags		= ctx->priv_flags;
 	out->mtu		= ctx->configured_mtu;
+	out->bpf_prog		= ctx->bpf_prog;
 }
 
 /* Vport identity and port debugfs outlive queue sets. */

@@ -3933,6 +3934,7 @@ static void mana_qset_install(struct mana_port_context *ctx,
 	ctx->tx_queue_size	= qset->tx_queue_size;
 	ctx->priv_flags		= qset->priv_flags;
 	ctx->configured_mtu	= qset->mtu;
+	ctx->bpf_prog		= qset->bpf_prog;
 }
 
 /* Scratch starts without SQs/RQs and borrows the port's EQ pool. Never call

@@ -3973,7 +3975,8 @@ void mana_qset_scratch_free(struct mana_port_context *scratch)
 int mana_alloc_qset(struct mana_port_context *apc,
 		    struct mana_port_context *scratch, unsigned int num_queues,
 		    unsigned int rx_queue_size, unsigned int tx_queue_size,
-		    u32 priv_flags, int mtu, struct mana_qset *out)
+		    u32 priv_flags, int mtu, struct bpf_prog *bpf_prog,
+		    struct mana_qset *out)
 {
 	struct net_device *ndev = scratch->ndev;
 	int err;

@@ -3986,6 +3989,7 @@ int mana_alloc_qset(struct mana_port_context *apc,
 	scratch->priv_flags	= priv_flags;
 
 	scratch->configured_mtu	= mtu;
+	scratch->bpf_prog	= bpf_prog;
 
 	err = mana_init_port_context(scratch);
 	if (err)

@@ -709,7 +709,7 @@ static int mana_set_channels(struct net_device *ndev,
 
 	err = mana_alloc_qset(apc, scratch, new_count, apc->rx_queue_size,
 			      apc->tx_queue_size, apc->priv_flags,
-			      apc->configured_mtu, &newq);
+			      apc->configured_mtu, apc->bpf_prog, &newq);
 	if (err)
 		goto free_scratch;
 

@@ -798,7 +798,8 @@ static int mana_set_ringparam(struct net_device *ndev,
 	}
 
 	err = mana_alloc_qset(apc, scratch, apc->num_queues, new_rx, new_tx,
-			      apc->priv_flags, apc->configured_mtu, &newq);
+			      apc->priv_flags, apc->configured_mtu,
+			      apc->bpf_prog, &newq);
 	if (err) {
 		NL_SET_ERR_MSG_FMT(extack, "failed to change ring params: %d",
 				   err);

@@ -886,9 +887,9 @@ static int mana_set_priv_flags(struct net_device *ndev, u32 priv_flags)
 		goto clear_flag;
 	}
 
-	err = mana_alloc_qset(apc, scratch, apc->num_queues,
-			      apc->rx_queue_size, apc->tx_queue_size,
-			      priv_flags, apc->configured_mtu, &newq);
+	err = mana_alloc_qset(apc, scratch, apc->num_queues, apc->rx_queue_size,
+			      apc->tx_queue_size, priv_flags,
+			      apc->configured_mtu, apc->bpf_prog, &newq);
 	if (err)
 		goto free_scratch;
 

@@ -698,6 +698,8 @@ struct mana_qset {
 	u32			priv_flags;
 
 	int			mtu;
+	struct bpf_prog		*bpf_prog;
+
 };
 
 netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev);

@@ -715,7 +717,8 @@ void mana_qset_scratch_free(struct mana_port_context *scratch);
 int mana_alloc_qset(struct mana_port_context *apc,
 		    struct mana_port_context *scratch, unsigned int num_queues,
 		    unsigned int rx_queue_size, unsigned int tx_queue_size,
-		    u32 priv_flags, int mtu, struct mana_qset *out);
+		    u32 priv_flags, int mtu, struct bpf_prog *bpf_prog,
+		    struct mana_qset *out);
 int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq,
 		      struct mana_qset *out_old);
 void mana_publish_close_if_needed(struct mana_port_context *apc);