This patch introduces a new debugfs entry to read current Package C-state residency values and, one new kernel API to read the Package C-10 residency counter.
Package C-state residency MSRs provide useful debug information about system idle states. In idle states system must enter deeper Package C-states. For example, on Intel Skylake/Kabylake based systems one should expect more Package C-8 residency in "Idle Display On" scenarios compared to higher Package C-states. With a self refresh display panel we must expect even more deeper Package C-9/C-10 residencies indicating more power savings. Package C-states depend not only on Core C-States but also on various IP blocks power gating status and LTR values. For Intel Core SoCs Package C-10 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 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_residency Package C2 : 0xec2e21735f Package C3 : 0xc30113ba4 Package C6 : 0x9ef4be15c5 Package C7 : 0x1e011904 Package C8 : 0x3c5653cfe5a Package C9 : 0x0 Package C10 : 0x16fff4289 Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhard...@intel.com> --- * Applied on top of "Make the driver PCH family agnostic" sent by Srinivas * Tested on 4.13-rc4 as well as on the "testing" branch of the platform/drivers/x86. arch/x86/include/asm/pmc_core.h | 1 + drivers/platform/x86/intel_pmc_core.c | 74 +++++++++++++++++++++++++++++++++++ drivers/platform/x86/intel_pmc_core.h | 1 + 3 files changed, 76 insertions(+) diff --git a/arch/x86/include/asm/pmc_core.h b/arch/x86/include/asm/pmc_core.h index d4855f11136d..99f48e63fafc 100644 --- a/arch/x86/include/asm/pmc_core.h +++ b/arch/x86/include/asm/pmc_core.h @@ -23,5 +23,6 @@ /* API to read SLP_S0_RESIDENCY counter */ int intel_pmc_slp_s0_counter_read(u32 *data); +int intel_pkgc10_counter_read(u64 *data); #endif /* _ASM_PMC_CORE_H */ diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c index 17e08b42b0a9..5eea99f24b10 100644 --- a/drivers/platform/x86/intel_pmc_core.c +++ b/drivers/platform/x86/intel_pmc_core.c @@ -29,11 +29,24 @@ #include <asm/cpu_device_id.h> #include <asm/intel-family.h> #include <asm/pmc_core.h> +#include <asm/msr.h> #include "intel_pmc_core.h" static struct pmc_dev pmc; +/* PKGC MSRs are common across Intel Core cpus */ +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}, @@ -110,6 +123,7 @@ static const struct pmc_reg_map spt_reg_map = { .pfear_sts = spt_pfear_map, .mphy_sts = spt_mphy_map, .pll_sts = spt_pll_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, @@ -147,6 +161,26 @@ static inline u32 pmc_core_adjust_slp_s0_step(u32 value) } /** + * intel_pkgc10_counter_read() - Read Package C10 residency. + * @data: Out param that contains current PC10 count by reading MSR 0x632 + * + * MSR_PKG_C10_RESIDENCY counter counts at the same frequency as the TSC. + * BIT 0:59 represent the value since the last reset that this package is in + * processor specific C10 states. + * BIT 63:60 are reserved. + * + * Return: an error code or 0 on success. + */ +int intel_pkgc10_counter_read(u64 *data) +{ + if (!data) + return -EINVAL; + + return rdmsrl_safe(MSR_PKG_C10_RESIDENCY, data); +} +EXPORT_SYMBOL_GPL(intel_pkgc10_counter_read); + +/** * intel_pmc_slp_s0_counter_read() - Read SLP_S0 residency. * @data: Out param that contains current SLP_S0 count. * @@ -430,6 +464,39 @@ static const struct file_operations pmc_core_ltr_ignore_ops = { .release = single_release, }; +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, err; + + for (index = 0; map[index].name ; index++) { + err = rdmsrl_safe(map[index].bit_mask, &pcstate_count); + if (err) { + pr_debug("Failed to read %s residency MSR", + map[index].name); + return err; + } + seq_printf(s, "%s\t : 0x%llx\n", map[index].name, + pcstate_count); + } + + return 0; +} + +static int pmc_core_pkgc_open(struct inode *inode, struct file *file) +{ + return single_open(file, pmc_core_pkgc_show, inode->i_private); +} + +static const struct file_operations pmc_core_pkgc_ops = { + .open = pmc_core_pkgc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev) { debugfs_remove_recursive(pmcdev->dbgfs_dir); @@ -474,6 +541,13 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev) if (!file) goto err; + file = debugfs_create_file("package_cstate_residency", + S_IFREG | S_IRUGO, dir, pmcdev, + &pmc_core_pkgc_ops); + + if (!file) + goto err; + return 0; err: pmc_core_dbgfs_unregister(pmcdev); diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h index 3d225a9cc09f..4423b84c53c0 100644 --- a/drivers/platform/x86/intel_pmc_core.h +++ b/drivers/platform/x86/intel_pmc_core.h @@ -150,6 +150,7 @@ struct pmc_reg_map { const struct pmc_bit_map *pfear_sts; const struct pmc_bit_map *mphy_sts; const struct pmc_bit_map *pll_sts; + const struct pmc_bit_map *msr_sts; const u32 slp_s0_offset; const u32 ltr_ignore_offset; const u32 base_address; -- 2.7.4
