On Sun, 23 Jan 2022 16:30:57 -0800
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> From: Ben Widawsky <ben.widawsky@xxxxxxxxx>
>
> In preparation for defining a cxl_port object to represent the decoder
> resources of a memory expander capture the compont register base
component
> address.
>
> The port driver uses the component register base to enumerate the HDM
> Decoder Capability structure. Unlike other cxl_port objects the endpoint
> port decodes from upstream SPA to downstream DPA rather than upstream
> port to downstream port.
>
> Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> [djbw: clarify changelog]
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> drivers/cxl/cxlmem.h | 3 +++
> drivers/cxl/pci.c | 11 +++++++++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index fca2d1b5f6ff..90d67fff5bed 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -116,6 +116,7 @@ struct cxl_mbox_cmd {
> * @active_persistent_bytes: sum of hard + soft persistent
> * @next_volatile_bytes: volatile capacity change pending device reset
> * @next_persistent_bytes: persistent capacity change pending device reset
> + * @component_reg_phys: register base of component registers
> * @mbox_send: @dev specific transport for transmitting mailbox commands
> *
> * See section 8.2.9.5.2 Capacity Configuration and Label Storage for
> @@ -145,6 +146,8 @@ struct cxl_dev_state {
> u64 next_volatile_bytes;
> u64 next_persistent_bytes;
>
> + resource_size_t component_reg_phys;
> +
> int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
> };
>
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index c29d50660c21..e54dbdf9ac15 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -416,6 +416,17 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> if (rc)
> return rc;
>
> + /*
> + * If the component registers can't be found, the cxl_pci driver may
> + * still be useful for management functions so don't return an error.
> + */
> + cxlds->component_reg_phys = CXL_RESOURCE_NONE;
> + rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
> + if (rc)
> + dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
> +
> + cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map);
> +
> rc = cxl_pci_setup_mailbox(cxlds);
> if (rc)
> return rc;
>
