Re: [RFC PATCH 03/13] cxl: export core function for type2 devices

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

alucerop@ wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> CXL initialization by type2 devices requires to use current CXL kernel
> infrastructure only available to such core code. Type2 devices are by
> definition owned by specific vendor drivers which need to use part of
> that infrastructure for initialization.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
>  drivers/cxl/pci.c                   |  3 ++-
>  include/linux/cxlpci.h              |  2 ++
>  tools/testing/cxl/type2/pci_type2.c | 31 +++++++++++++++++++++++++++++
>  3 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index ccde33ac9c1c..497276302017 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -500,7 +500,7 @@ static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
>  	return 0;
>  }
>  
> -static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> +int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
>  			      struct cxl_register_map *map)
>  {
>  	int rc;
> @@ -520,6 +520,7 @@ static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
>  
>  	return cxl_setup_regs(map);
>  }
> +EXPORT_SYMBOL_NS_GPL(cxl_pci_setup_regs, CXL);

Any functionality in cxl_pci that you want to export to a 3rd party CXL
driver needs to move to drivers/cxl/core/pci.c

>  
>  static int cxl_pci_ras_unmask(struct pci_dev *pdev)
>  {
> diff --git a/include/linux/cxlpci.h b/include/linux/cxlpci.h
> index 93992a1c8eec..28fa4861a4f9 100644
> --- a/include/linux/cxlpci.h
> +++ b/include/linux/cxlpci.h
> @@ -130,4 +130,6 @@ 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);
> +int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> +		       struct cxl_register_map *map);
>  #endif /* __CXL_PCI_H__ */
> diff --git a/tools/testing/cxl/type2/pci_type2.c b/tools/testing/cxl/type2/pci_type2.c
> index 863ce7dc28ef..b12f13e676fb 100644
> --- a/tools/testing/cxl/type2/pci_type2.c
> +++ b/tools/testing/cxl/type2/pci_type2.c
> @@ -12,7 +12,9 @@ static int type2_pci_probe(struct pci_dev *pci_dev,
>  			   const struct pci_device_id *entry)
>  
>  {
> +	struct cxl_register_map map;
>  	u16 dvsec;
> +	int rc;
>  
>  	dvsec = pci_find_dvsec_capability(pci_dev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
>  
> @@ -35,6 +37,35 @@ static int type2_pci_probe(struct pci_dev *pci_dev,
>  	cxlds->dpa_res = DEFINE_RES_MEM(0, CXL_TYPE2_MEM_SIZE);
>  	cxlds->ram_res = DEFINE_RES_MEM_NAMED(0, CXL_TYPE2_MEM_SIZE, "ram");
>  
> +	rc = cxl_pci_setup_regs(pci_dev, CXL_REGLOC_RBI_MEMDEV, &map);
> +	if (rc)
> +		return rc;
> +
> +	rc = cxl_map_device_regs(&map, &cxlds->regs.device_regs);
> +	if (rc)
> +		return rc;
> +
> +	rc = cxl_pci_setup_regs(pci_dev, CXL_REGLOC_RBI_COMPONENT,
> +				&cxlds->reg_map);
> +	if (rc)
> +		dev_warn(&pci_dev->dev, "No component registers (%d)\n", rc);
> +
> +	rc = cxl_map_component_regs(&cxlds->reg_map, &cxlds->regs.component,
> +				    BIT(CXL_CM_CAP_CAP_ID_RAS));
> +	if (rc)
> +		dev_dbg(&pci_dev->dev, "Failed to map RAS capability.\n");
> +
> +	pci_info(pci_dev, "requesting resource...");

Setting aside whether this driver moves forward vs a cxl_test mock, if
you want the driver to be chatty use pci_dbg() or dev_dbg() not pci_info().