Merge branch 'mlx4-next'

Tariq Toukan says:

====================
mlx4 misc cleanups and improvements

This patchset contains some cleanups and improvements from the team
to the mlx4 Eth and core drivers.

Series generated against net-next commit:
5a7a5555 'net sched: stylistic cleanups'
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/cmd.c

@@ -785,17 +785,23 @@ int __mlx4_cmd(struct mlx4_dev *dev, u64 in_param, u64 *out_param,
 		return mlx4_cmd_reset_flow(dev, op, op_modifier, -EIO);
 
 	if (!mlx4_is_mfunc(dev) || (native && mlx4_is_master(dev))) {
+		int ret;
+
 		if (dev->persist->state & MLX4_DEVICE_STATE_INTERNAL_ERROR)
 			return mlx4_internal_err_ret_value(dev, op,
 							  op_modifier);
+		down_read(&mlx4_priv(dev)->cmd.switch_sem);
 		if (mlx4_priv(dev)->cmd.use_events)
-			return mlx4_cmd_wait(dev, in_param, out_param,
+			ret = mlx4_cmd_wait(dev, in_param, out_param,
 					    out_is_imm, in_modifier,
 					    op_modifier, op, timeout);
 		else
-			return mlx4_cmd_poll(dev, in_param, out_param,
+			ret = mlx4_cmd_poll(dev, in_param, out_param,
 					    out_is_imm, in_modifier,
 					    op_modifier, op, timeout);
+
+		up_read(&mlx4_priv(dev)->cmd.switch_sem);
+		return ret;
 	}
 	return mlx4_slave_cmd(dev, in_param, out_param, out_is_imm,
 			      in_modifier, op_modifier, op, timeout);
@@ -2454,6 +2460,7 @@ int mlx4_cmd_init(struct mlx4_dev *dev)
 	int flags = 0;
 
 	if (!priv->cmd.initialized) {
+		init_rwsem(&priv->cmd.switch_sem);
 		mutex_init(&priv->cmd.slave_cmd_mutex);
 		sema_init(&priv->cmd.poll_sem, 1);
 		priv->cmd.use_events = 0;
@@ -2583,6 +2590,7 @@ int mlx4_cmd_use_events(struct mlx4_dev *dev)
 	if (!priv->cmd.context)
 		return -ENOMEM;
 
+	down_write(&priv->cmd.switch_sem);
 	for (i = 0; i < priv->cmd.max_cmds; ++i) {
 		priv->cmd.context[i].token = i;
 		priv->cmd.context[i].next  = i + 1;
@@ -2606,6 +2614,7 @@ int mlx4_cmd_use_events(struct mlx4_dev *dev)
 
 	down(&priv->cmd.poll_sem);
 	priv->cmd.use_events = 1;
+	up_write(&priv->cmd.switch_sem);
 
 	return err;
 }
@@ -2618,6 +2627,7 @@ void mlx4_cmd_use_polling(struct mlx4_dev *dev)
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	int i;
 
+	down_write(&priv->cmd.switch_sem);
 	priv->cmd.use_events = 0;
 
 	for (i = 0; i < priv->cmd.max_cmds; ++i)
@@ -2626,6 +2636,7 @@ void mlx4_cmd_use_polling(struct mlx4_dev *dev)
 	kfree(priv->cmd.context);
 
 	up(&priv->cmd.poll_sem);
+	up_write(&priv->cmd.switch_sem);
 }
 
 struct mlx4_cmd_mailbox *mlx4_alloc_cmd_mailbox(struct mlx4_dev *dev)

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -72,7 +72,7 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
 	}
 	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE << order,
 			   frag_info->dma_dir);
-	if (dma_mapping_error(priv->ddev, dma)) {
+	if (unlikely(dma_mapping_error(priv->ddev, dma))) {
 		put_page(page);
 		return -ENOMEM;
 	}
@@ -108,7 +108,8 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 		    ring_alloc[i].page_size)
 			continue;
 
-		if (mlx4_alloc_pages(priv, &page_alloc[i], frag_info, gfp))
+		if (unlikely(mlx4_alloc_pages(priv, &page_alloc[i],
+					      frag_info, gfp)))
 			goto out;
 	}
 
@@ -585,7 +586,7 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
 		frag_info = &priv->frag_info[nr];
 		if (length <= frag_info->frag_prefix_size)
 			break;
-		if (!frags[nr].page)
+		if (unlikely(!frags[nr].page))
 			goto fail;
 
 		dma = be64_to_cpu(rx_desc->data[nr].addr);
@@ -625,7 +626,7 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
 	dma_addr_t dma;
 
 	skb = netdev_alloc_skb(priv->dev, SMALL_PACKET_SIZE + NET_IP_ALIGN);
-	if (!skb) {
+	if (unlikely(!skb)) {
 		en_dbg(RX_ERR, priv, "Failed allocating skb\n");
 		return NULL;
 	}
@@ -736,7 +737,8 @@ static int get_fixed_ipv6_csum(__wsum hw_checksum, struct sk_buff *skb,
 {
 	__wsum csum_pseudo_hdr = 0;
 
-	if (ipv6h->nexthdr == IPPROTO_FRAGMENT || ipv6h->nexthdr == IPPROTO_HOPOPTS)
+	if (unlikely(ipv6h->nexthdr == IPPROTO_FRAGMENT ||
+		     ipv6h->nexthdr == IPPROTO_HOPOPTS))
 		return -1;
 	hw_checksum = csum_add(hw_checksum, (__force __wsum)htons(ipv6h->nexthdr));
 
@@ -769,7 +771,7 @@ static int check_csum(struct mlx4_cqe *cqe, struct sk_buff *skb, void *va,
 		get_fixed_ipv4_csum(hw_checksum, skb, hdr);
 #if IS_ENABLED(CONFIG_IPV6)
 	else if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6))
-		if (get_fixed_ipv6_csum(hw_checksum, skb, hdr))
+		if (unlikely(get_fixed_ipv6_csum(hw_checksum, skb, hdr)))
 			return -1;
 #endif
 	return 0;
@@ -796,10 +798,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	u64 timestamp;
 	bool l2_tunnel;
 
-	if (!priv->port_up)
+	if (unlikely(!priv->port_up))
 		return 0;
 
-	if (budget <= 0)
+	if (unlikely(budget <= 0))
 		return polled;
 
 	/* Protect accesses to: ring->xdp_prog, priv->mac_hash list */
@@ -902,9 +904,9 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			case XDP_PASS:
 				break;
 			case XDP_TX:
-				if (!mlx4_en_xmit_frame(frags, dev,
+				if (likely(!mlx4_en_xmit_frame(frags, dev,
 							length, tx_index,
-							&doorbell_pending))
+							&doorbell_pending)))
 					goto consumed;
 				goto xdp_drop; /* Drop on xmit failure */
 			default:
@@ -912,7 +914,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			case XDP_ABORTED:
 			case XDP_DROP:
 xdp_drop:
-				if (mlx4_en_rx_recycle(ring, frags))
+				if (likely(mlx4_en_rx_recycle(ring, frags)))
 					goto consumed;
 				goto next;
 			}
@@ -1016,7 +1018,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 
 		/* GRO not possible, complete processing here */
 		skb = mlx4_en_rx_skb(priv, rx_desc, frags, length);
-		if (!skb) {
+		if (unlikely(!skb)) {
 			ring->dropped++;
 			goto next;
 		}

drivers/net/ethernet/mellanox/mlx4/mlx4.h

@@ -46,6 +46,7 @@
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <net/devlink.h>
+#include <linux/rwsem.h>
 
 #include <linux/mlx4/device.h>
 #include <linux/mlx4/driver.h>
@@ -627,6 +628,7 @@ struct mlx4_cmd {
 	struct mutex		slave_cmd_mutex;
 	struct semaphore	poll_sem;
 	struct semaphore	event_sem;
+	struct rw_semaphore	switch_sem;
 	int			max_cmds;
 	spinlock_t		context_lock;
 	int			free_head;

drivers/net/ethernet/mellanox/mlx4/srq.c

@@ -45,15 +45,12 @@ void mlx4_srq_event(struct mlx4_dev *dev, u32 srqn, int event_type)
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	struct mlx4_srq *srq;
 
-	spin_lock(&srq_table->lock);
-
+	rcu_read_lock();
 	srq = radix_tree_lookup(&srq_table->tree, srqn & (dev->caps.num_srqs - 1));
+	rcu_read_unlock();
 	if (srq)
 		atomic_inc(&srq->refcount);
-
-	spin_unlock(&srq_table->lock);
-
-	if (!srq) {
+	else {
 		mlx4_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
 		return;
 	}
@@ -301,12 +298,11 @@ struct mlx4_srq *mlx4_srq_lookup(struct mlx4_dev *dev, u32 srqn)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	struct mlx4_srq *srq;
-	unsigned long flags;
 
-	spin_lock_irqsave(&srq_table->lock, flags);
+	rcu_read_lock();
 	srq = radix_tree_lookup(&srq_table->tree,
 				srqn & (dev->caps.num_srqs - 1));
-	spin_unlock_irqrestore(&srq_table->lock, flags);
+	rcu_read_unlock();
 
 	return srq;
 }