Subject: Re: [PATCH v8 05/27] cxl: move pci generic code

From: Jonathan Cameron <[email-masked]>
Date: Tue, 24 Dec 2024 17:19:43 +0000

On Mon, 16 Dec 2024 16:10:20 +0000
[email-masked] wrote:

> From: Alejandro Lucero <[email-masked]>
> 
> 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 helper functions from cxl/pci.c to cxl/core/pci.c in order to be
> exported and shared with CXL Type2 device initialization.

Rebase gone wrong?  What happened to call of 
cxl_dport_map_rcd_linkcap() in the original code for instance.

Jonathan

> 
> Signed-off-by: Alejandro Lucero <[email-masked]>
> Reviewed-by: Dave Jiang <[email-masked]>
> Reviewed-by: Ben Cheatham <[email-masked]>
> Reviewed-by: Fan Ni <[email-masked]>
> ---
>  drivers/cxl/core/pci.c | 62 ++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlpci.h   |  3 ++
>  drivers/cxl/pci.c      | 71 ------------------------------------------
>  3 files changed, 65 insertions(+), 71 deletions(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index bc098b2ce55d..3cca3ae438cd 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -1034,6 +1034,68 @@ 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, unsigned long *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");
> +
>  int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c)
>  {
>  	int speed, bw;
> diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
> index eb59019fe5f3..985cca3c3350 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, unsigned long *caps);
>  #endif /* __CXL_PCI_H__ */
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 1fcc53df1217..89056449625f 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -467,77 +467,6 @@ 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_dport *dport)
> -{
> -	resource_size_t component_reg_phys;
> -
> -	*map = (struct cxl_register_map) {
> -		.host = &pdev->dev,
> -		.resource = CXL_RESOURCE_NONE,
> -	};
> -
> -	struct cxl_port *port __free(put_cxl_port) =
> -		cxl_pci_find_port(pdev, &dport);
> -	if (!port)
> -		return -EPROBE_DEFER;
> -
> -	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
> -	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,
> -			      unsigned long *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)) {
> -		struct cxl_dport *dport;
> -		struct cxl_port *port __free(put_cxl_port) =
> -			cxl_pci_find_port(pdev, &dport);
> -		if (!port)
> -			return -EPROBE_DEFER;
> -
> -		rc = cxl_rcrb_get_comp_regs(pdev, map, dport);
> -		if (rc)
> -			return rc;
> -
> -		rc = cxl_dport_map_rcd_linkcap(pdev, dport);
> -		if (rc)
> -			return rc;
> -
> -	} else 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);