linux-kernel - [PATCH] mlx5: simplify EQ interrupt polling logic

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Message-ID: <20241023205113.255866-1-csander@purestorage.com>
Date: Wed, 23 Oct 2024 14:51:12 -0600
From: Caleb Sander Mateos <csander@...estorage.com>
To: Saeed Mahameed <saeedm@...dia.com>,
	Leon Romanovsky <leon@...nel.org>,
	Tariq Toukan <tariqt@...dia.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>
Cc: Caleb Sander Mateos <csander@...estorage.com>,
	netdev@...r.kernel.org,
	linux-rdma@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] mlx5: simplify EQ interrupt polling logic

Use a while loop in mlx5_eq_comp_int() and mlx5_eq_async_int() to
clarify the EQE polling logic. This consolidates the next_eqe_sw() calls
for the first and subequent iterations. It also avoids a goto. Turn the
num_eqes < MLX5_EQ_POLLING_BUDGET check into a break condition.

Signed-off-by: Caleb Sander Mateos <csander@...estorage.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/eq.c | 22 +++++++-------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
index 68cb86b37e56..859dcf09b770 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
@@ -114,15 +114,11 @@ static int mlx5_eq_comp_int(struct notifier_block *nb,
 	struct mlx5_eq *eq = &eq_comp->core;
 	struct mlx5_eqe *eqe;
 	int num_eqes = 0;
 	u32 cqn = -1;
 
-	eqe = next_eqe_sw(eq);
-	if (!eqe)
-		goto out;
-
-	do {
+	while ((eqe = next_eqe_sw(eq))) {
 		struct mlx5_core_cq *cq;
 
 		/* Make sure we read EQ entry contents after we've
 		 * checked the ownership bit.
 		 */
@@ -140,13 +136,14 @@ static int mlx5_eq_comp_int(struct notifier_block *nb,
 					    "Completion event for bogus CQ 0x%x\n", cqn);
 		}
 
 		++eq->cons_index;
 
-	} while ((++num_eqes < MLX5_EQ_POLLING_BUDGET) && (eqe = next_eqe_sw(eq)));
+		if (++num_eqes >= MLX5_EQ_POLLING_BUDGET)
+			break;
+	}
 
-out:
 	eq_update_ci(eq, 1);
 
 	if (cqn != -1)
 		tasklet_schedule(&eq_comp->tasklet_ctx.task);
 
@@ -213,15 +210,11 @@ static int mlx5_eq_async_int(struct notifier_block *nb,
 	eqt = dev->priv.eq_table;
 
 	recovery = action == ASYNC_EQ_RECOVER;
 	mlx5_eq_async_int_lock(eq_async, recovery, &flags);
 
-	eqe = next_eqe_sw(eq);
-	if (!eqe)
-		goto out;
-
-	do {
+	while ((eqe = next_eqe_sw(eq))) {
 		/*
 		 * Make sure we read EQ entry contents after we've
 		 * checked the ownership bit.
 		 */
 		dma_rmb();
@@ -229,13 +222,14 @@ static int mlx5_eq_async_int(struct notifier_block *nb,
 		atomic_notifier_call_chain(&eqt->nh[eqe->type], eqe->type, eqe);
 		atomic_notifier_call_chain(&eqt->nh[MLX5_EVENT_TYPE_NOTIFY_ANY], eqe->type, eqe);
 
 		++eq->cons_index;
 
-	} while ((++num_eqes < MLX5_EQ_POLLING_BUDGET) && (eqe = next_eqe_sw(eq)));
+		if (++num_eqes >= MLX5_EQ_POLLING_BUDGET)
+			break;
+	}
 
-out:
 	eq_update_ci(eq, 1);
 	mlx5_eq_async_int_unlock(eq_async, recovery, &flags);
 
 	return unlikely(recovery) ? num_eqes : 0;
 }
-- 
2.45.2