linux-kernel - Re: [PATCH v2 2/5] platform/x86:intel/pmc: Move telemetry endpoint register handling

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Message-ID: <a40aa7c1-084c-e49c-33ee-57088a58debe@linux.intel.com>
Date: Mon, 30 Jun 2025 14:25:19 +0300 (EEST)
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: Xi Pardee <xi.pardee@...ux.intel.com>
cc: irenic.rajneesh@...il.com, david.e.box@...ux.intel.com, 
    Hans de Goede <hdegoede@...hat.com>, platform-driver-x86@...r.kernel.org, 
    LKML <linux-kernel@...r.kernel.org>, linux-pm@...r.kernel.org
Subject: Re: [PATCH v2 2/5] platform/x86:intel/pmc: Move telemetry endpoint
 register handling

On Tue, 24 Jun 2025, Xi Pardee wrote:

> Move telemetry endpoint handling to pmc_core_get_telem_info(). This
> is a preparation patch to introduce a new table to obtain Low Power
> Mode substate requirement data for platforms starting from Panther
> Lake.
> 
> Signed-off-by: Xi Pardee <xi.pardee@...ux.intel.com>
> ---
>  drivers/platform/x86/intel/pmc/core.c | 51 +++++++++++++--------------
>  1 file changed, 25 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index 540cd2fb0673b..a1dd80bdbd413 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -1399,36 +1399,23 @@ static u32 pmc_core_find_guid(struct pmc_info *list, const struct pmc_reg_map *m
>   * +----+---------------------------------------------------------+
>   *
>   */
> -static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct pci_dev *pcidev)
> +static int pmc_core_pmt_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc,
> +				    struct telem_endpoint *ep)
>  {
> -	struct telem_endpoint *ep;
>  	const u8 *lpm_indices;
>  	int num_maps, mode_offset = 0;
>  	int ret, mode;
>  	int lpm_size;
> -	u32 guid;
>  
>  	lpm_indices = pmc->map->lpm_reg_index;
>  	num_maps = pmc->map->lpm_num_maps;
>  	lpm_size = LPM_MAX_NUM_MODES * num_maps;
>  
> -	guid = pmc_core_find_guid(pmcdev->regmap_list, pmc->map);
> -	if (!guid)
> -		return -ENXIO;
> -
> -	ep = pmt_telem_find_and_register_endpoint(pcidev, guid, 0);
> -	if (IS_ERR(ep)) {
> -		dev_dbg(&pmcdev->pdev->dev, "couldn't get telem endpoint %pe", ep);
> -		return -EPROBE_DEFER;
> -	}
> -
>  	pmc->lpm_req_regs = devm_kzalloc(&pmcdev->pdev->dev,
>  					 lpm_size * sizeof(u32),
>  					 GFP_KERNEL);
> -	if (!pmc->lpm_req_regs) {
> -		ret = -ENOMEM;
> -		goto unregister_ep;
> -	}
> +	if (!pmc->lpm_req_regs)
> +		return -ENOMEM;
>  
>  	mode_offset = LPM_HEADER_OFFSET + LPM_MODE_OFFSET;
>  	pmc_for_each_mode(mode, pmcdev) {
> @@ -1442,23 +1429,21 @@ static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct
>  			if (ret) {
>  				dev_err(&pmcdev->pdev->dev,
>  					"couldn't read Low Power Mode requirements: %d\n", ret);
> -				goto unregister_ep;
> +				return ret;
>  			}
>  			++req_offset;
>  		}
>  		mode_offset += LPM_REG_COUNT + LPM_MODE_OFFSET;
>  	}
> -
> -unregister_ep:
> -	pmt_telem_unregister_endpoint(ep);
> -
>  	return ret;
>  }
>  
> -static int pmc_core_ssram_get_lpm_reqs(struct pmc_dev *pmcdev, int func)
> +static int pmc_core_get_telem_info(struct pmc_dev *pmcdev, int func)
>  {
>  	struct pci_dev *pcidev __free(pci_dev_put) = NULL;
> +	struct telem_endpoint *ep;
>  	unsigned int i;
> +	u32 guid;
>  	int ret;
>  
>  	pcidev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(20, func));
> @@ -1466,10 +1451,24 @@ static int pmc_core_ssram_get_lpm_reqs(struct pmc_dev *pmcdev, int func)
>  		return -ENODEV;
>  
>  	for (i = 0; i < ARRAY_SIZE(pmcdev->pmcs); ++i) {
> -		if (!pmcdev->pmcs[i])
> +		struct pmc *pmc;
> +
> +		pmc = pmcdev->pmcs[i];
> +		if (!pmc)
>  			continue;
>  
> -		ret = pmc_core_get_lpm_req(pmcdev, pmcdev->pmcs[i], pcidev);
> +		guid = pmc_core_find_guid(pmcdev->regmap_list, pmc->map);
> +		if (!guid)
> +			return -ENXIO;
> +
> +		ep = pmt_telem_find_and_register_endpoint(pcidev, guid, 0);
> +		if (IS_ERR(ep)) {
> +			dev_dbg(&pmcdev->pdev->dev, "couldn't get telem endpoint %pe", ep);
> +			return -EPROBE_DEFER;
> +		}
> +
> +		ret = pmc_core_pmt_get_lpm_req(pmcdev, pmc, ep);
> +		pmt_telem_unregister_endpoint(ep);
>  		if (ret)
>  			return ret;
>  	}
> @@ -1583,7 +1582,7 @@ int generic_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_info)
>  		pmc_core_punit_pmt_init(pmcdev, pmc_dev_info->dmu_guid);
>  
>  	if (ssram) {
> -		ret = pmc_core_ssram_get_lpm_reqs(pmcdev, pmc_dev_info->pci_func);
> +		ret = pmc_core_get_telem_info(pmcdev, pmc_dev_info->pci_func);
>  		if (ret)
>  			goto unmap_regbase;
>  	}
> 

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>

-- 
 i.