Subject: Re: [PATCH rdma-next 4/4] RDMA/mlx5: Use query_special_contexts for mkeys

From: Jason Gunthorpe <[email-masked]>
Date: Wed, 4 Jan 2023 09:03:06 -0400

On Wed, Jan 04, 2023 at 10:11:25AM +0200, Leon Romanovsky wrote:
> -int mlx5_cmd_null_mkey(struct mlx5_core_dev *dev, u32 *null_mkey)
> -{
> -	u32 out[MLX5_ST_SZ_DW(query_special_contexts_out)] = {};
> -	u32 in[MLX5_ST_SZ_DW(query_special_contexts_in)] = {};
> -	int err;
> +	err = mlx5_cmd_exec_inout(dev->mdev, query_special_contexts, in, out);
> +	if (err)
> +		return err;
>  
> -	MLX5_SET(query_special_contexts_in, in, opcode,
> -		 MLX5_CMD_OP_QUERY_SPECIAL_CONTEXTS);
> -	err = mlx5_cmd_exec_inout(dev, query_special_contexts, in, out);
> -	if (!err)
> -		*null_mkey = MLX5_GET(query_special_contexts_out, out,
> -				      null_mkey);
> -	return err;
> +	if (MLX5_CAP_GEN(dev->mdev, dump_fill_mkey))
> +		dev->mkeys.dump_fill_mkey = MLX5_GET(query_special_contexts_out,
> +						     out, dump_fill_mkey);
> +
> +	if (MLX5_CAP_GEN(dev->mdev, null_mkey))
> +		dev->mkeys.null_mkey = cpu_to_be32(
> +			MLX5_GET(query_special_contexts_out, out, null_mkey));
> +
> +	if (MLX5_CAP_GEN(dev->mdev, terminate_scatter_list_mkey)) {
> +		dev->mkeys.terminate_scatter_list_mkey =
> +			cpu_to_be32(MLX5_GET(query_special_contexts_out, out,
> +					     terminate_scatter_list_mkey));
> +		return 0;
> +	}
> +	dev->mkeys.terminate_scatter_list_mkey =
> +		MLX5_TERMINATE_SCATTER_LIST_LKEY;

This is already stored in the core dev, why are you recalculating it
here?

Jason