linux-kernel - Re: [PATCH 4/9] platform/x86: intel_pmc_core: Show LPM residency in microseconds

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Date:   Wed, 7 Apr 2021 16:23:42 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     "David E. Box" <david.e.box@...ux.intel.com>,
        irenic.rajneesh@...il.com, mgross@...ux.intel.com,
        gayatri.kammela@...el.com
Cc:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/9] platform/x86: intel_pmc_core: Show LPM residency in
 microseconds

Hi,

On 4/1/21 5:05 AM, David E. Box wrote:
> From: Gayatri Kammela <gayatri.kammela@...el.com>
> 
> Modify the low power mode (LPM or sub-state) residency counters to display
> in microseconds just like the slp_s0_residency counter. The granularity of
> the counter is approximately 30.5us per tick. Double this value then divide
> by two to maintain accuracy.
> 
> Signed-off-by: Gayatri Kammela <gayatri.kammela@...el.com>
> Signed-off-by: David E. Box <david.e.box@...ux.intel.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@...hat.com>

Regards,

Hans

> ---
>  drivers/platform/x86/intel_pmc_core.c | 14 ++++++++++++--
>  drivers/platform/x86/intel_pmc_core.h |  3 +++
>  2 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
> index ce300c2942d0..ba0db301f07b 100644
> --- a/drivers/platform/x86/intel_pmc_core.c
> +++ b/drivers/platform/x86/intel_pmc_core.c
> @@ -578,6 +578,7 @@ static const struct pmc_reg_map tgl_reg_map = {
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
>  	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
>  	.lpm_num_maps = TGL_LPM_NUM_MAPS,
> +	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
>  	.lpm_en_offset = TGL_LPM_EN_OFFSET,
>  	.lpm_priority_offset = TGL_LPM_PRI_OFFSET,
>  	.lpm_residency_offset = TGL_LPM_RESIDENCY_OFFSET,
> @@ -1026,17 +1027,26 @@ static int pmc_core_ltr_show(struct seq_file *s, void *unused)
>  }
>  DEFINE_SHOW_ATTRIBUTE(pmc_core_ltr);
>  
> +static inline u64 adjust_lpm_residency(struct pmc_dev *pmcdev, u32 offset,
> +				       const int lpm_adj_x2)
> +{
> +	u64 lpm_res = pmc_core_reg_read(pmcdev, offset);
> +
> +	return GET_X2_COUNTER((u64)lpm_adj_x2 * lpm_res);
> +}
> +
>  static int pmc_core_substate_res_show(struct seq_file *s, void *unused)
>  {
>  	struct pmc_dev *pmcdev = s->private;
> +	const int lpm_adj_x2 = pmcdev->map->lpm_res_counter_step_x2;
>  	u32 offset = pmcdev->map->lpm_residency_offset;
>  	int i, mode;
>  
>  	seq_printf(s, "%-10s %-15s\n", "Substate", "Residency");
>  
>  	pmc_for_each_mode(i, mode, pmcdev) {
> -		seq_printf(s, "%-10s %-15u\n", pmc_lpm_modes[mode],
> -			   pmc_core_reg_read(pmcdev, offset + (4 * mode)));
> +		seq_printf(s, "%-10s %-15llu\n", pmc_lpm_modes[mode],
> +			   adjust_lpm_residency(pmcdev, offset + (4 * mode), lpm_adj_x2));
>  	}
>  
>  	return 0;
> diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
> index 5a4e3a49f5b1..3800c1ba6fb7 100644
> --- a/drivers/platform/x86/intel_pmc_core.h
> +++ b/drivers/platform/x86/intel_pmc_core.h
> @@ -188,9 +188,11 @@ enum ppfear_regs {
>  #define ICL_PMC_SLP_S0_RES_COUNTER_STEP		0x64
>  
>  #define LPM_MAX_NUM_MODES			8
> +#define GET_X2_COUNTER(v)			((v) >> 1)
>  
>  #define TGL_NUM_IP_IGN_ALLOWED			22
>  #define TGL_PMC_SLP_S0_RES_COUNTER_STEP		0x7A
> +#define TGL_PMC_LPM_RES_COUNTER_STEP_X2		61	/* 30.5us * 2 */
>  
>  /*
>   * Tigerlake Power Management Controller register offsets
> @@ -263,6 +265,7 @@ struct pmc_reg_map {
>  	const u32 pm_vric1_offset;
>  	/* Low Power Mode registers */
>  	const int lpm_num_maps;
> +	const int lpm_res_counter_step_x2;
>  	const u32 lpm_en_offset;
>  	const u32 lpm_priority_offset;
>  	const u32 lpm_residency_offset;
>