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> --- 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
