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Subject: Re: [PATCH] vdpa/mlx5: Fix wrong use of bit numbers
To:     Eli Cohen <elic@nvidia.com>, mst@redhat.com,
        linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org
References: <20210301062817.39331-1-elic@nvidia.com>
From:   Jason Wang <jasowang@redhat.com>
Message-ID: <959916f2-5fc9-bdb4-31ca-632fe0d98979@redhat.com>
Date:   Mon, 1 Mar 2021 15:52:45 +0800
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On 2021/3/1 2:28 下午, Eli Cohen wrote:
> VIRTIO_F_VERSION_1 is a bit number. Use BIT_ULL() with mask
> conditionals.
>
> Also, in mlx5_vdpa_is_little_endian() use BIT_ULL for consistency with
> the rest of the code.
>
> Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> Signed-off-by: Eli Cohen <elic@nvidia.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   drivers/vdpa/mlx5/net/mlx5_vnet.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index dc7031132fff..7d21b857a94a 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -821,7 +821,7 @@ static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque
>   	MLX5_SET(virtio_q, vq_ctx, event_qpn_or_msix, mvq->fwqp.mqp.qpn);
>   	MLX5_SET(virtio_q, vq_ctx, queue_size, mvq->num_ent);
>   	MLX5_SET(virtio_q, vq_ctx, virtio_version_1_0,
> -		 !!(ndev->mvdev.actual_features & VIRTIO_F_VERSION_1));
> +		 !!(ndev->mvdev.actual_features & BIT_ULL(VIRTIO_F_VERSION_1)));
>   	MLX5_SET64(virtio_q, vq_ctx, desc_addr, mvq->desc_addr);
>   	MLX5_SET64(virtio_q, vq_ctx, used_addr, mvq->device_addr);
>   	MLX5_SET64(virtio_q, vq_ctx, available_addr, mvq->driver_addr);
> @@ -1578,7 +1578,7 @@ static void teardown_virtqueues(struct mlx5_vdpa_net *ndev)
>   static inline bool mlx5_vdpa_is_little_endian(struct mlx5_vdpa_dev *mvdev)
>   {
>   	return virtio_legacy_is_little_endian() ||
> -		(mvdev->actual_features & (1ULL << VIRTIO_F_VERSION_1));
> +		(mvdev->actual_features & BIT_ULL(VIRTIO_F_VERSION_1));
>   }
>   
>   static __virtio16 cpu_to_mlx5vdpa16(struct mlx5_vdpa_dev *mvdev, u16 val)