Re: [PATCH v9 07/27] sfc: use cxl api for regs setup and checking

Dan Williams
2025-01-18T01:53:35Z

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.
>
> 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>
> ---
> drivers/net/ethernet/sfc/efx_cxl.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c
> index 12c9d50cbb26..29368d010adc 100644
> --- a/drivers/net/ethernet/sfc/efx_cxl.c
> +++ b/drivers/net/ethernet/sfc/efx_cxl.c
> @@ -22,6 +22,8 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
> {
> struct efx_nic *efx = &probe_data->efx;
> struct pci_dev *pci_dev = efx->pci_dev;
> + DECLARE_BITMAP(expected, CXL_MAX_CAPS);
> + DECLARE_BITMAP(found, CXL_MAX_CAPS);
> struct efx_cxl *cxl;
> struct resource res;
> u16 dvsec;
> @@ -64,6 +66,25 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
> goto err_resource_set;
> }
>
> + rc = cxl_pci_accel_setup_regs(pci_dev, cxl->cxlds);
> + if (rc) {
> + pci_err(pci_dev, "CXL accel setup regs failed");
> + goto err_resource_set;
> + }
> +
> + bitmap_clear(expected, 0, CXL_MAX_CAPS);
> + set_bit(CXL_DEV_CAP_HDM, expected);
> + set_bit(CXL_DEV_CAP_HDM, expected);
> + set_bit(CXL_DEV_CAP_RAS, expected);
> +
> + if (!cxl_pci_check_caps(cxl->cxlds, expected, found)) {
> + pci_err(pci_dev,
> + "CXL device capabilities found(%pb) not as expected(%pb)",
> + found, expected);
> + rc = -EIO;
> + goto err_resource_set;
> + }
> +

Walk the existing valid bits in the reg maps. If you want to do this
with bitmaps you can convert reg_map valid bits into a bitmap locally,
but that redundant infrastructure can be left out of the core.