Re: [PATCH 09/10] platform/x86: intel_pmc_core: Add Package cstates residency info

From: Anshuman Gupta <anshuman.gupta@intel.com>
To: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
Cc: platform-driver-x86@vger.kernel.org, dvhart@infradead.org,
	andy@infradead.org, linux-kernel@vger.kernel.org,
	Arjan van de Ven <arjan@linux.intel.com>,
	"David E. Box" <david.e.box@intel.com>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Len Brown <len.brown@intel.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: [PATCH 09/10] platform/x86: intel_pmc_core: Add Package cstates residency info
Date: Mon, 11 Feb 2019 22:11:18 +0530	[thread overview]
Message-ID: <20190211164118.GA23796@genxfsim-desktop> (raw)
In-Reply-To: <20190201073234.13280-10-rajneesh.bhardwaj@linux.intel.com>

On Fri, Feb 01, 2019 at 01:02:33PM +0530, Rajneesh Bhardwaj wrote:
> This patch introduces a new debugfs entry to read current Package
> cstate residency counters. A similar variant of this patch was discussed
> earlier "https://patchwork.kernel.org/patch/9908563/" but didn't make it
> into mainline for various reasons. Current version only adds debugfs
> entry which is quite useful for S0ix debug but excludes the exported API
> that was there in initial version. Though there are tools like turbostat
> and socwatch which can also show this info but sometimes its more
> practical to have it here as it's hard to switch between various tools for
> S0ix debug when pmc_core driver is the primary debug tool. Internal and
> external customers have requested for this patch to be included in the
> PMC driver on many occasions and Google Chrome OS team has already included
> it in their builds. This becomes handy when requesting logs from external
> customers who may not always have above mentioned tools in their integrated
> kernel builds.
> 
> Package cstate residency MSRs provide useful debug information about
> system idle states. In idle states system must enter deeper Package
> cstates. Package cstates depend not only on Core cstates but also on
> various IP block's power gating status and LTR values.
> 
> For Intel Core SoCs Package C10 entry is a must for deeper sleep states
> such as S0ix. "Suspend-to-idle"  should ideally take this path:
> PC0 -> PC10 -> S0ix. For S0ix debug, its logical to check for
> Package C10 residency first if for some reason system fails to enter S0ix.
> 
> Please refer to this link for MSR details:
> https://software.intel.com/sites/default/files/managed/22/0d/335592-sdm-vol-4.pdf
> 
> Usage:
> cat /sys/kernel/debug/pmc_core/package_cstate_show
> Package C2       : 0xec2e21735f
> Package C3       : 0xc30113ba4
> Package C6       : 0x9ef4be15c5
> Package C7       : 0x1e011904
> Package C8       : 0x3c5653cfe5a
> Package C9       : 0x0
> Package C10      : 0x16fff4289
> 
> Cc: Arjan van de Ven <arjan@linux.intel.com>
> Cc: "David E. Box" <david.e.box@intel.com>
> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> Cc: Anshuman Gupta <anshuman.gupta@intel.com>
> Cc: Len Brown <len.brown@intel.com>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
  Tested-by: Anshuman Gupta <anshuman.gupta@intel.com> 	
  Acked-by: Anshuman Gupta <anshuman.gupta@intel.com> 	
> ---
>  drivers/platform/x86/intel_pmc_core.c | 38 +++++++++++++++++++++++++++
>  drivers/platform/x86/intel_pmc_core.h |  1 +
>  2 files changed, 39 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
> index 400946b7a3b5..4e7aa1711148 100644
> --- a/drivers/platform/x86/intel_pmc_core.c
> +++ b/drivers/platform/x86/intel_pmc_core.c
> @@ -22,11 +22,24 @@
>  
>  #include <asm/cpu_device_id.h>
>  #include <asm/intel-family.h>
> +#include <asm/msr.h>
>  
>  #include "intel_pmc_core.h"
>  
>  static struct pmc_dev pmc;
>  
> +/* PKGC MSRs are common across Intel Core SoCs */
> +static const struct pmc_bit_map msr_map[] = {
> +	{"Package C2",                  MSR_PKG_C2_RESIDENCY},
> +	{"Package C3",                  MSR_PKG_C3_RESIDENCY},
> +	{"Package C6",                  MSR_PKG_C6_RESIDENCY},
> +	{"Package C7",                  MSR_PKG_C7_RESIDENCY},
> +	{"Package C8",                  MSR_PKG_C8_RESIDENCY},
> +	{"Package C9",                  MSR_PKG_C9_RESIDENCY},
> +	{"Package C10",                 MSR_PKG_C10_RESIDENCY},
> +	{}
> +};
> +
>  static const struct pmc_bit_map spt_pll_map[] = {
>  	{"MIPI PLL",			SPT_PMC_BIT_MPHY_CMN_LANE0},
>  	{"GEN2 USB2PCIE2 PLL",		SPT_PMC_BIT_MPHY_CMN_LANE1},
> @@ -129,6 +142,7 @@ static const struct pmc_reg_map spt_reg_map = {
>  	.mphy_sts = spt_mphy_map,
>  	.pll_sts = spt_pll_map,
>  	.ltr_show_sts = spt_ltr_show_map,
> +	.msr_sts = msr_map,
>  	.slp_s0_offset = SPT_PMC_SLP_S0_RES_COUNTER_OFFSET,
>  	.ltr_ignore_offset = SPT_PMC_LTR_IGNORE_OFFSET,
>  	.regmap_length = SPT_PMC_MMIO_REG_LEN,
> @@ -318,6 +332,7 @@ static const struct pmc_reg_map cnp_reg_map = {
>  	.slp_s0_offset = CNP_PMC_SLP_S0_RES_COUNTER_OFFSET,
>  	.slps0_dbg_maps = cnp_slps0_dbg_maps,
>  	.ltr_show_sts = cnp_ltr_show_map,
> +	.msr_sts = msr_map,
>  	.slps0_dbg_offset = CNP_PMC_SLPS0_DBG_OFFSET,
>  	.ltr_ignore_offset = CNP_PMC_LTR_IGNORE_OFFSET,
>  	.regmap_length = CNP_PMC_MMIO_REG_LEN,
> @@ -333,6 +348,7 @@ static const struct pmc_reg_map icl_reg_map = {
>  	.slp_s0_offset = CNP_PMC_SLP_S0_RES_COUNTER_OFFSET,
>  	.slps0_dbg_maps = cnp_slps0_dbg_maps,
>  	.ltr_show_sts = cnp_ltr_show_map,
> +	.msr_sts = msr_map,
>  	.slps0_dbg_offset = CNP_PMC_SLPS0_DBG_OFFSET,
>  	.ltr_ignore_offset = CNP_PMC_LTR_IGNORE_OFFSET,
>  	.regmap_length = CNP_PMC_MMIO_REG_LEN,
> @@ -709,6 +725,25 @@ static int pmc_core_ltr_show(struct seq_file *s, void *unused)
>  }
>  DEFINE_SHOW_ATTRIBUTE(pmc_core_ltr);
>  
> +static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
> +{
> +	struct pmc_dev *pmcdev = s->private;
> +	const struct pmc_bit_map *map = pmcdev->map->msr_sts;
> +	u64 pcstate_count;
> +	int index;
> +
> +	for (index = 0; map[index].name ; index++) {
> +		if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
> +			continue;
> +
> +		seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
> +			   pcstate_count);
> +	}
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(pmc_core_pkgc);
> +
>  static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
>  {
>  	debugfs_remove_recursive(pmcdev->dbgfs_dir);
> @@ -735,6 +770,9 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
>  
>  	debugfs_create_file("ltr_show", 0444, dir, pmcdev, &pmc_core_ltr_fops);
>  
> +	debugfs_create_file("package_cstate_show", 0444, dir, pmcdev,
> +			    &pmc_core_pkgc_fops);
> +
>  	if (pmcdev->map->pll_sts)
>  		debugfs_create_file("pll_status", 0444, dir, pmcdev,
>  				    &pmc_core_pll_fops);
> diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
> index 78dd4229489d..6f1b64808075 100644
> --- a/drivers/platform/x86/intel_pmc_core.h
> +++ b/drivers/platform/x86/intel_pmc_core.h
> @@ -214,6 +214,7 @@ struct pmc_reg_map {
>  	const struct pmc_bit_map *pll_sts;
>  	const struct pmc_bit_map **slps0_dbg_maps;
>  	const struct pmc_bit_map *ltr_show_sts;
> +	const struct pmc_bit_map *msr_sts;
>  	const u32 slp_s0_offset;
>  	const u32 ltr_ignore_offset;
>  	const int regmap_length;
> -- 
> 2.17.1
> 

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