Re: [PATCH v17 14/22] sfc: get endpoint decoder

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Tue, 24 Jun 2025 15:13:47 +0100
<alejandro.lucero-palau@amd.com> wrote:

> From: Alejandro Lucero <alucerop@amd.com>
> 
> Use cxl api for getting DPA (Device Physical Address) to use through an
> endpoint decoder.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> Reviewed-by: Martin Habets <habetsm.xilinx@gmail.com>
> Acked-by: Edward Cree <ecree.xilinx@gmail.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>  drivers/net/ethernet/sfc/efx_cxl.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c
> index c0adfd99cc78..ffbf0e706330 100644
> --- a/drivers/net/ethernet/sfc/efx_cxl.c
> +++ b/drivers/net/ethernet/sfc/efx_cxl.c
> @@ -108,6 +108,14 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
>  		goto put_root_decoder;
>  	}
>  
> +	cxl->cxled = cxl_request_dpa(cxl->cxlmd, CXL_PARTMODE_RAM,
> +				     EFX_CTPIO_BUFFER_SIZE);
> +	if (IS_ERR(cxl->cxled)) {
> +		pci_err(pci_dev, "CXL accel request DPA failed");
> +		rc = PTR_ERR(cxl->cxled);
> +		goto put_root_decoder;
> +	}
> +
>  	probe_data->cxl = cxl;
>  
>  	goto endpoint_release;
> @@ -121,8 +129,10 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
>  
>  void efx_cxl_exit(struct efx_probe_data *probe_data)
>  {
> -	if (probe_data->cxl)
> +	if (probe_data->cxl) {
Given this is going to get more complex I'd be tempted to go with early exist
approach for !cxl

	if (!probe_data->cxl)
		return;

	cxl_dpa_free()
etc.

> +		cxl_dpa_free(probe_data->cxl->cxled);
>  		cxl_put_root_decoder(probe_data->cxl->cxlrd);
> +	}
>  }
>  
>  MODULE_IMPORT_NS("CXL");