Re: [PATCH 09/10] platform/x86: intel_pmc_core: Add Package cstates residency info
From: Anshuman Gupta
Date: Mon Feb 11 2019 - 11:44:26 EST
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@xxxxxxxxxxxxxxx>
> Cc: "David E. Box" <david.e.box@xxxxxxxxx>
> Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> Cc: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
> Cc: Len Brown <len.brown@xxxxxxxxx>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxxxxxxxx>
Tested-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
Acked-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
> ---
> 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
>
--