Re: [PATCH v6 10/15] platform/x86/intel/pmc/ssram: Add PCI platform data

[Ilpo Järvinen]

On Sun, 31 May 2026, David E. Box wrote:

> Add per-device platform data for SSRAM telemetry PCI IDs and route probe
> through a method selector driven by id->driver_data.
> 
> This is a preparatory refactor for follow-on discovery methods while
> preserving current behavior: all supported IDs continue to use the PCI
> initialization path.
> 
> Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
> ---
> V6 changes:
>   - Reordered from v5 patch 12 to maintain logical flow before probe
>     state refactoring.
> 
> V5 - No changes
> 
> V4 - No changes
> 
> V3 - No changes
> 
> V2 changes:
>   - Added missing <linux/device.h> include for dev_dbg() usage in probe
> 
>  .../platform/x86/intel/pmc/ssram_telemetry.c  | 71 +++++++++++++++----
>  1 file changed, 57 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel/pmc/ssram_telemetry.c b/drivers/platform/x86/intel/pmc/ssram_telemetry.c
> index 1deb4d71da3f..3d1f5a17903b 100644
> --- a/drivers/platform/x86/intel/pmc/ssram_telemetry.c
> +++ b/drivers/platform/x86/intel/pmc/ssram_telemetry.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <linux/cleanup.h>
> +#include <linux/device.h>
>  #include <linux/intel_vsec.h>
>  #include <linux/pci.h>
>  #include <linux/types.h>
> @@ -24,6 +25,18 @@
>  
>  DEFINE_FREE(pmc_ssram_telemetry_iounmap, void __iomem *, if (_T) iounmap(_T))
>  
> +enum resource_method {
> +	RES_METHOD_PCI,
> +};
> +
> +struct ssram_type {
> +	enum resource_method method;
> +};
> +
> +static const struct ssram_type pci_main = {
> +	.method = RES_METHOD_PCI,
> +};
> +
>  static struct pmc_ssram_telemetry *pmc_ssram_telems;
>  static bool device_probed;
>  
> @@ -69,7 +82,7 @@ static inline u64 get_base(void __iomem *addr, u32 offset)
>  }
>  
>  static int
> -pmc_ssram_telemetry_get_pmc(struct pci_dev *pcidev, unsigned int pmc_idx, u32 offset)
> +pmc_ssram_telemetry_get_pmc_pci(struct pci_dev *pcidev, unsigned int pmc_idx, u32 offset)
>  {
>  	void __iomem __free(pmc_ssram_telemetry_iounmap) *tmp_ssram = NULL;
>  	void __iomem __free(pmc_ssram_telemetry_iounmap) *ssram = NULL;
> @@ -109,6 +122,20 @@ pmc_ssram_telemetry_get_pmc(struct pci_dev *pcidev, unsigned int pmc_idx, u32 of
>  	return pmc_ssram_telemetry_add_pmt(pcidev, ssram_base, ssram);
>  }
>  
> +static int pmc_ssram_telemetry_pci_init(struct pci_dev *pcidev)
> +{
> +	int ret;
> +
> +	ret = pmc_ssram_telemetry_get_pmc_pci(pcidev, PMC_IDX_MAIN, 0);
> +	if (ret)
> +		return ret;
> +
> +	pmc_ssram_telemetry_get_pmc_pci(pcidev, PMC_IDX_IOE, SSRAM_IOE_OFFSET);
> +	pmc_ssram_telemetry_get_pmc_pci(pcidev, PMC_IDX_PCH, SSRAM_PCH_OFFSET);
> +
> +	return ret;

return 0;

> +}
> +
>  /**
>   * pmc_ssram_telemetry_get_pmc_info() - Get a PMC devid and base_addr information
>   * @pmc_idx:               Index of the PMC
> @@ -151,6 +178,8 @@ EXPORT_SYMBOL_GPL(pmc_ssram_telemetry_get_pmc_info);
>  
>  static int pmc_ssram_telemetry_probe(struct pci_dev *pcidev, const struct pci_device_id *id)
>  {
> +	const struct ssram_type *ssram_type;
> +	enum resource_method method;
>  	int ret;
>  
>  	pmc_ssram_telems = devm_kzalloc(&pcidev->dev, sizeof(*pmc_ssram_telems) * MAX_NUM_PMC,
> @@ -160,18 +189,25 @@ static int pmc_ssram_telemetry_probe(struct pci_dev *pcidev, const struct pci_de
>  		goto probe_finish;
>  	}
>  
> +	ssram_type = (const struct ssram_type *)id->driver_data;
> +	if (!ssram_type) {
> +		dev_dbg(&pcidev->dev, "missing driver data\n");
> +		ret = -EINVAL;
> +		goto probe_finish;
> +	}
> +
> +	method = ssram_type->method;
> +
>  	ret = pcim_enable_device(pcidev);
>  	if (ret) {
>  		dev_dbg(&pcidev->dev, "failed to enable PMC SSRAM device\n");
>  		goto probe_finish;
>  	}
>  
> -	ret = pmc_ssram_telemetry_get_pmc(pcidev, PMC_IDX_MAIN, 0);
> -	if (ret)
> -		goto probe_finish;
> -
> -	pmc_ssram_telemetry_get_pmc(pcidev, PMC_IDX_IOE, SSRAM_IOE_OFFSET);
> -	pmc_ssram_telemetry_get_pmc(pcidev, PMC_IDX_PCH, SSRAM_PCH_OFFSET);
> +	if (method == RES_METHOD_PCI)
> +		ret = pmc_ssram_telemetry_pci_init(pcidev);
> +	else
> +		ret = -EINVAL;
>  
>  probe_finish:
>  	/*
> @@ -184,13 +220,20 @@ static int pmc_ssram_telemetry_probe(struct pci_dev *pcidev, const struct pci_de
>  }
>  
>  static const struct pci_device_id pmc_ssram_telemetry_pci_ids[] = {
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_MTL_SOCM) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_ARL_SOCS) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_ARL_SOCM) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_LNL_SOCM) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_PTL_PCDH) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_PTL_PCDP) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_WCL_PCDN) },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_MTL_SOCM),
> +		.driver_data = (kernel_ulong_t)&pci_main },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_ARL_SOCS),
> +		.driver_data = (kernel_ulong_t)&pci_main },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_ARL_SOCM),
> +		.driver_data = (kernel_ulong_t)&pci_main },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_LNL_SOCM),
> +		.driver_data = (kernel_ulong_t)&pci_main },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_PTL_PCDH),
> +		.driver_data = (kernel_ulong_t)&pci_main },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_PTL_PCDP),
> +		.driver_data = (kernel_ulong_t)&pci_main },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PMC_DEVID_WCL_PCDN),
> +		.driver_data = (kernel_ulong_t)&pci_main },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(pci, pmc_ssram_telemetry_pci_ids);
> 

-- 
 i.