Re: [PATCH v16 06/22] sfc: make regs setup with checking and set media ready

[Dan Williams <dan.j.williams@intel.com>]

alejandro.lucero-palau@ wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> Use cxl code for registers discovery and mapping.
> 
> Validate capabilities found based on those registers against expected
> capabilities.
> 
> Set media ready explicitly as there is no means for doing so without
> a mailbox and without the related cxl register, not mandatory for type2.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> Reviewed-by: Martin Habets <habetsm.xilinx@gmail.com>
> Reviewed-by: Zhi Wang <zhi@nvidia.com>
> Acked-by: Edward Cree <ecree.xilinx@gmail.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
> ---
>  drivers/net/ethernet/sfc/efx_cxl.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c
> index 753d5b7d49b6..e94af8bf3a79 100644
> --- a/drivers/net/ethernet/sfc/efx_cxl.c
> +++ b/drivers/net/ethernet/sfc/efx_cxl.c
> @@ -19,10 +19,13 @@
>  
>  int efx_cxl_init(struct efx_probe_data *probe_data)
>  {
> +	DECLARE_BITMAP(expected, CXL_MAX_CAPS) = {};
> +	DECLARE_BITMAP(found, CXL_MAX_CAPS) = {};
>  	struct efx_nic *efx = &probe_data->efx;
>  	struct pci_dev *pci_dev = efx->pci_dev;
>  	struct efx_cxl *cxl;
>  	u16 dvsec;
> +	int rc;
>  
>  	probe_data->cxl_pio_initialised = false;
>  
> @@ -43,6 +46,29 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
>  	if (!cxl)
>  		return -ENOMEM;
>  
> +	set_bit(CXL_DEV_CAP_HDM, expected);
> +	set_bit(CXL_DEV_CAP_RAS, expected);
> +
> +	rc = cxl_pci_accel_setup_regs(pci_dev, &cxl->cxlds, found);
> +	if (rc) {
> +		pci_err(pci_dev, "CXL accel setup regs failed");
> +		return rc;
> +	}
> +
> +	/*
> +	 * Checking mandatory caps are there as, at least, a subset of those
> +	 * found.
> +	 */
> +	if (cxl_check_caps(pci_dev, expected, found))
> +		return -ENXIO;

This all looks like an obfuscated way of writing:

    cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
    if (!map.component_map.ras.valid || !map.component_map.hdm_decoder.valid)
         /* sfc cxl expectations not met */