Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tariq Toukan <tariqt@mellanox.com>,
        Eran Ben Elisha <eranbe@mellanox.com>,
        Saeed Mahameed <saeedm@mellanox.com>
Subject: [PATCH 4.18 015/235] net/mlx5: Use u16 for Work Queue buffer fragment size
Date:   Mon, 24 Sep 2018 13:50:01 +0200
Message-Id: <20180924113106.028019927@linuxfoundation.org>
In-Reply-To: <20180924113103.999624566@linuxfoundation.org>
References: <20180924113103.999624566@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tariq Toukan <tariqt@mellanox.com>

[ Upstream commit 8d71e818506718e8d7032ce824b5c74a17d4f7a5 ]

Minimal stride size is 16.
Hence, the number of strides in a fragment (of PAGE_SIZE)
is <= PAGE_SIZE / 16 <= 4K.

u16 is sufficient to represent this.

Fixes: 388ca8be0037 ("IB/mlx5: Implement fragmented completion queue (CQ)")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/wq.c |    4 ++--
 drivers/net/ethernet/mellanox/mlx5/core/wq.h |    2 +-
 include/linux/mlx5/driver.h                  |    2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/wq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/wq.c
@@ -39,9 +39,9 @@ u32 mlx5_wq_cyc_get_size(struct mlx5_wq_
 	return (u32)wq->fbc.sz_m1 + 1;
 }
 
-u32 mlx5_wq_cyc_get_frag_size(struct mlx5_wq_cyc *wq)
+u16 mlx5_wq_cyc_get_frag_size(struct mlx5_wq_cyc *wq)
 {
-	return (u32)wq->fbc.frag_sz_m1 + 1;
+	return wq->fbc.frag_sz_m1 + 1;
 }
 
 u32 mlx5_cqwq_get_size(struct mlx5_cqwq *wq)
--- a/drivers/net/ethernet/mellanox/mlx5/core/wq.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/wq.h
@@ -80,7 +80,7 @@ int mlx5_wq_cyc_create(struct mlx5_core_
 		       void *wqc, struct mlx5_wq_cyc *wq,
 		       struct mlx5_wq_ctrl *wq_ctrl);
 u32 mlx5_wq_cyc_get_size(struct mlx5_wq_cyc *wq);
-u32 mlx5_wq_cyc_get_frag_size(struct mlx5_wq_cyc *wq);
+u16 mlx5_wq_cyc_get_frag_size(struct mlx5_wq_cyc *wq);
 
 int mlx5_wq_qp_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		      void *qpc, struct mlx5_wq_qp *wq,
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -357,7 +357,7 @@ struct mlx5_frag_buf {
 struct mlx5_frag_buf_ctrl {
 	struct mlx5_frag_buf	frag_buf;
 	u32			sz_m1;
-	u32			frag_sz_m1;
+	u16			frag_sz_m1;
 	u32			strides_offset;
 	u8			log_sz;
 	u8			log_stride;