Re: [PATCH v3 04/20] cxl: move pci generic code

[Dave Jiang <dave.jiang@intel.com>]

On 9/7/24 1:18 AM, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> Inside cxl/core/pci.c there are helpers for CXL PCIe initialization
> meanwhile cxl/pci.c implements the functionality for a Type3 device
> initialization.
> 
> Move those functions required also for Type2 initialization to
> cxl/core/pci.c with a specific function using that moved code added in
> a following patch.

Please consider rephrasing as:

Move helper functions from cxl/pci.c to cxl/core/pci.c in order to be
exported and shared with CXL Type2 device initialization.

> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
>  drivers/cxl/core/pci.c | 63 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlpci.h   |  3 ++
>  drivers/cxl/pci.c      | 60 ----------------------------------------
>  3 files changed, 66 insertions(+), 60 deletions(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 57370d9beb32..bf57f081ef8f 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -1079,6 +1079,69 @@ bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_reset_detected, CXL);
>  
> +/*
> + * Assume that any RCIEP that emits the CXL memory expander class code
> + * is an RCD
> + */
> +bool is_cxl_restricted(struct pci_dev *pdev)
> +{
> +	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
> +}
> +EXPORT_SYMBOL_NS_GPL(is_cxl_restricted, CXL);
> +
> +static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
> +				  struct cxl_register_map *map)
> +{
> +	struct cxl_port *port;
> +	struct cxl_dport *dport;
> +	resource_size_t component_reg_phys;
> +
> +	*map = (struct cxl_register_map) {
> +		.host = &pdev->dev,
> +		.resource = CXL_RESOURCE_NONE,
> +	};
> +
> +	port = cxl_pci_find_port(pdev, &dport);
> +	if (!port)
> +		return -EPROBE_DEFER;
> +
> +	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
> +
> +	put_device(&port->dev);
> +
> +	if (component_reg_phys == CXL_RESOURCE_NONE)
> +		return -ENXIO;
> +
> +	map->resource = component_reg_phys;
> +	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
> +	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
> +
> +	return 0;
> +}
> +
> +int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> +		       struct cxl_register_map *map,
> +		       u32 *caps)
> +{
> +	int rc;
> +
> +	rc = cxl_find_regblock(pdev, type, map);
> +
> +	/*
> +	 * If the Register Locator DVSEC does not exist, check if it
> +	 * is an RCH and try to extract the Component Registers from
> +	 * an RCRB.
> +	 */
> +	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
> +		rc = cxl_rcrb_get_comp_regs(pdev, map);
> +
> +	if (rc)
> +		return rc;
> +
> +	return cxl_setup_regs(map, caps);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_pci_setup_regs, CXL);
> +
>  bool cxl_pci_check_caps(struct cxl_dev_state *cxlds, u32 expected_caps,
>  			u32 *current_caps)
>  {
> diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
> index eb59019fe5f3..786b811effba 100644
> --- a/drivers/cxl/cxlpci.h
> +++ b/drivers/cxl/cxlpci.h
> @@ -113,4 +113,7 @@ void read_cdat_data(struct cxl_port *port);
>  void cxl_cor_error_detected(struct pci_dev *pdev);
>  pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
>  				    pci_channel_state_t state);
> +bool is_cxl_restricted(struct pci_dev *pdev);
> +int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> +		       struct cxl_register_map *map, u32 *caps);

Does this need to go to a different header like include/cxl/pci.h or something for type2 consumption?

DJ

>  #endif /* __CXL_PCI_H__ */
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index bec660357eec..2b85f87549c2 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -463,66 +463,6 @@ static int cxl_pci_setup_mailbox(struct cxl_memdev_state *mds, bool irq_avail)
>  	return 0;
>  }
>  
> -/*
> - * Assume that any RCIEP that emits the CXL memory expander class code
> - * is an RCD
> - */
> -static bool is_cxl_restricted(struct pci_dev *pdev)
> -{
> -	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
> -}
> -
> -static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
> -				  struct cxl_register_map *map)
> -{
> -	struct cxl_port *port;
> -	struct cxl_dport *dport;
> -	resource_size_t component_reg_phys;
> -
> -	*map = (struct cxl_register_map) {
> -		.host = &pdev->dev,
> -		.resource = CXL_RESOURCE_NONE,
> -	};
> -
> -	port = cxl_pci_find_port(pdev, &dport);
> -	if (!port)
> -		return -EPROBE_DEFER;
> -
> -	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
> -
> -	put_device(&port->dev);
> -
> -	if (component_reg_phys == CXL_RESOURCE_NONE)
> -		return -ENXIO;
> -
> -	map->resource = component_reg_phys;
> -	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
> -	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
> -
> -	return 0;
> -}
> -
> -static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> -			      struct cxl_register_map *map, u32 *caps)
> -{
> -	int rc;
> -
> -	rc = cxl_find_regblock(pdev, type, map);
> -
> -	/*
> -	 * If the Register Locator DVSEC does not exist, check if it
> -	 * is an RCH and try to extract the Component Registers from
> -	 * an RCRB.
> -	 */
> -	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
> -		rc = cxl_rcrb_get_comp_regs(pdev, map);
> -
> -	if (rc)
> -		return rc;
> -
> -	return cxl_setup_regs(map, caps);
> -}
> -
>  static int cxl_pci_ras_unmask(struct pci_dev *pdev)
>  {
>  	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);