Subject: Re: [PATCH v8 06/27] cxl: add function for type2 cxl regs setup

From: Jonathan Cameron <[email-masked]>
Date: Tue, 24 Dec 2024 17:22:36 +0000

On Mon, 16 Dec 2024 16:10:21 +0000
[email-masked] wrote:

> From: Alejandro Lucero <[email-masked]>
> 
> Create a new function for a type2 device initialising
> cxl_dev_state struct regarding cxl regs setup and mapping.
> 
> Signed-off-by: Alejandro Lucero <[email-masked]>
> Reviewed-by: Dave Jiang <[email-masked]>
> Reviewed-by: Fan Ni <[email-masked]>
Comments below.

J
> ---
>  drivers/cxl/core/pci.c | 47 ++++++++++++++++++++++++++++++++++++++++++
>  include/cxl/cxl.h      |  2 ++
>  2 files changed, 49 insertions(+)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 3cca3ae438cd..0b578ff14cc3 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -1096,6 +1096,53 @@ int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_pci_setup_regs, "CXL");
>  
> +static int cxl_pci_setup_memdev_regs(struct pci_dev *pdev,
> +				     struct cxl_dev_state *cxlds)
> +{
> +	struct cxl_register_map map;
> +	int rc;
> +
> +	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map,
> +				cxlds->capabilities);
> +	/*
> +	 * This call returning a non-zero value is not considered an error since

Error code perhaps rather than non-zero value?

> +	 * these regs are not mandatory for Type2. If they do exist then mapping
> +	 * them should not fail.
> +	 */
> +	if (rc)
> +		return 0;
> +
> +	return cxl_map_device_regs(&map, &cxlds->regs.device_regs);
> +}
> +
> +int cxl_pci_accel_setup_regs(struct pci_dev *pdev, struct cxl_dev_state *cxlds)
> +{
> +	int rc;
> +
> +	rc = cxl_pci_setup_memdev_regs(pdev, cxlds);
> +	if (rc)
> +		return rc;
> +
> +	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT,
> +				&cxlds->reg_map, cxlds->capabilities);
> +	if (rc) {
> +		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
> +		return rc;
> +	}
> +
> +	if (!test_bit(CXL_CM_CAP_CAP_ID_RAS, cxlds->capabilities))

rc is 0.  I doubt that's the intent - if it is, return 0;

> +		return rc;
> +
> +	rc = cxl_map_component_regs(&cxlds->reg_map,
> +				    &cxlds->regs.component,
> +				    BIT(CXL_CM_CAP_CAP_ID_RAS));
> +	if (rc)
> +		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
> +
> +	return rc;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_pci_accel_setup_regs, "CXL");

> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
> index 05f06bfd2c29..18fb01adcf19 100644
> --- a/include/cxl/cxl.h
> +++ b/include/cxl/cxl.h
> @@ -5,6 +5,7 @@
>  #define __CXL_H
>  
>  #include <linux/ioport.h>
> +#include <linux/pci.h>

Use a forwards def if all you need is
struct pci_dev;

>  
>  enum cxl_resource {
>  	CXL_RES_DPA,
> @@ -40,4 +41,5 @@ int cxl_set_resource(struct cxl_dev_state *cxlds, struct resource res,
>  bool cxl_pci_check_caps(struct cxl_dev_state *cxlds,
>  			unsigned long *expected_caps,
>  			unsigned long *current_caps);
> +int cxl_pci_accel_setup_regs(struct pci_dev *pdev, struct cxl_dev_state *cxlds);
>  #endif