linux-kernel - [PATCH net-next 02/10] net/mlx5: Remove unused 'offset' field from mlx5_sq

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1757499891-596641-3-git-send-email-tariqt@nvidia.com>
Date: Wed, 10 Sep 2025 13:24:43 +0300
From: Tariq Toukan <tariqt@...dia.com>
To: Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>, Andrew Lunn <andrew+netdev@...n.ch>, "David
 S. Miller" <davem@...emloft.net>
CC: Jiri Pirko <jiri@...nulli.us>, Jonathan Corbet <corbet@....net>, "Leon
 Romanovsky" <leon@...nel.org>, Jason Gunthorpe <jgg@...pe.ca>, Saeed Mahameed
	<saeedm@...dia.com>, Tariq Toukan <tariqt@...dia.com>, Mark Bloch
	<mbloch@...dia.com>, Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann
	<daniel@...earbox.net>, Jesper Dangaard Brouer <hawk@...nel.org>, "John
 Fastabend" <john.fastabend@...il.com>, <netdev@...r.kernel.org>,
	<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linux-rdma@...r.kernel.org>, <bpf@...r.kernel.org>, Gal Pressman
	<gal@...dia.com>, Cosmin Ratiu <cratiu@...dia.com>, Dragos Tatulea
	<dtatulea@...dia.com>, Jiri Pirko <jiri@...dia.com>
Subject: [PATCH net-next 02/10] net/mlx5: Remove unused 'offset' field from mlx5_sq_bfreg

From: Cosmin Ratiu <cratiu@...dia.com>

The 'offset' field was introduced in the original commit [1] and never
used until commit [2], which added an unnecessary use.

Remove the field and refactor the write-combining test to use a local
variable instead.

[1] commit a6d51b68611e ("net/mlx5: Introduce blue flame register
allocator")
[2] commit d98995b4bf98 ("net/mlx5: Reimplement write combining test")
Signed-off-by: Cosmin Ratiu <cratiu@...dia.com>
Reviewed-by: Dragos Tatulea <dtatulea@...dia.com>
Signed-off-by: Tariq Toukan <tariqt@...dia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/wc.c | 12 +++++++-----
 include/linux/mlx5/driver.h                  |  1 -
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/wc.c b/drivers/net/ethernet/mellanox/mlx5/core/wc.c
index 2f0316616fa4..276594586404 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/wc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/wc.c
@@ -255,7 +255,8 @@ static void mlx5_wc_destroy_sq(struct mlx5_wc_sq *sq)
 	mlx5_wq_destroy(&sq->wq_ctrl);
 }
 
-static void mlx5_wc_post_nop(struct mlx5_wc_sq *sq, bool signaled)
+static void mlx5_wc_post_nop(struct mlx5_wc_sq *sq, unsigned int *offset,
+			     bool signaled)
 {
 	int buf_size = (1 << MLX5_CAP_GEN(sq->cq.mdev, log_bf_reg_size)) / 2;
 	struct mlx5_wqe_ctrl_seg *ctrl;
@@ -288,10 +289,10 @@ static void mlx5_wc_post_nop(struct mlx5_wc_sq *sq, bool signaled)
 	 */
 	wmb();
 
-	__iowrite64_copy(sq->bfreg.map + sq->bfreg.offset, mmio_wqe,
+	__iowrite64_copy(sq->bfreg.map + *offset, mmio_wqe,
 			 sizeof(mmio_wqe) / 8);
 
-	sq->bfreg.offset ^= buf_size;
+	*offset ^= buf_size;
 }
 
 static int mlx5_wc_poll_cq(struct mlx5_wc_sq *sq)
@@ -332,6 +333,7 @@ static int mlx5_wc_poll_cq(struct mlx5_wc_sq *sq)
 
 static void mlx5_core_test_wc(struct mlx5_core_dev *mdev)
 {
+	unsigned int offset = 0;
 	unsigned long expires;
 	struct mlx5_wc_sq *sq;
 	int i, err;
@@ -358,9 +360,9 @@ static void mlx5_core_test_wc(struct mlx5_core_dev *mdev)
 		goto err_create_sq;
 
 	for (i = 0; i < TEST_WC_NUM_WQES - 1; i++)
-		mlx5_wc_post_nop(sq, false);
+		mlx5_wc_post_nop(sq, &offset, false);
 
-	mlx5_wc_post_nop(sq, true);
+	mlx5_wc_post_nop(sq, &offset, true);
 
 	expires = jiffies + TEST_WC_POLLING_MAX_TIME_JIFFIES;
 	do {
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index fcfc18bfeba9..5a85b6d91ba3 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -434,7 +434,6 @@ struct mlx5_sq_bfreg {
 	struct mlx5_uars_page  *up;
 	bool			wc;
 	u32			index;
-	unsigned int		offset;
 };
 
 struct mlx5_core_health {
-- 
2.31.1