From patchwork Wed Oct 4 23:43:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: srinivas pandruvada X-Patchwork-Id: 9985971 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BBFEA6028E for ; Wed, 4 Oct 2017 23:43:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 98ECC28C21 for ; Wed, 4 Oct 2017 23:43:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7A7DF28C35; Wed, 4 Oct 2017 23:43:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B6D228C21 for ; Wed, 4 Oct 2017 23:43:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751132AbdJDXni (ORCPT ); Wed, 4 Oct 2017 19:43:38 -0400 Received: from mga11.intel.com ([192.55.52.93]:33240 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbdJDXnh (ORCPT ); Wed, 4 Oct 2017 19:43:37 -0400 Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Oct 2017 16:43:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,479,1500966000"; d="scan'208";a="135281419" Received: from spandruv-desk.jf.intel.com ([10.54.75.11]) by orsmga004.jf.intel.com with ESMTP; 04 Oct 2017 16:43:36 -0700 From: Srinivas Pandruvada To: rjw@rjwysocki.net Cc: lv.zheng@intel.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Srinivas Pandruvada Subject: [PATCH] ACPI / LPIT: Add Low Power Idle Table (LPIT) support Date: Wed, 4 Oct 2017 16:43:33 -0700 Message-Id: <1507160613-56852-1-git-send-email-srinivas.pandruvada@linux.intel.com> X-Mailer: git-send-email 2.7.5 MIME-Version: 1.0 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Added functionality to read LPIT table, which provides: - Sysfs interface to read residency counters via /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us Here the count "low_power_idle_cpu_residency_us" shows the time spent by CPU package in low power state. This is read via MSR interface, which points to MSR for PKG C10. Here the count "low_power_idle_system_residency_us" show the count the system was in low power state. This is read via MMIO interface. This is mapped to SLP_S0 residency on modern Intel systems. This residency is achieved only when CPU is in PKG C10 and all functional blocks are in low power state. It is possible that none of the above counters present or anyone of the counter present or all counters present. For example: On my Kabylake system both of the above counters present. After suspend to idle these counts updated and prints: 6916179 6998564 This counter can be read by tools like turbostat to display. Or it can be used to debug, if modern systems are reaching desired low power state. - Provides an interface to read residency counter memory address This address can be used to get the base address of PMC memory mapped IO. This is utilized by intel_pmc_core driver to print more debug information. Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf Signed-off-by: Srinivas Pandruvada --- Documentation/acpi/lpit.txt | 26 ++++++++ drivers/acpi/Kconfig | 5 ++ drivers/acpi/Makefile | 1 + drivers/acpi/acpi_lpit.c | 157 ++++++++++++++++++++++++++++++++++++++++++++ drivers/acpi/scan.c | 3 + include/acpi/acpi_lpit.h | 34 ++++++++++ 6 files changed, 226 insertions(+) create mode 100644 Documentation/acpi/lpit.txt create mode 100644 drivers/acpi/acpi_lpit.c create mode 100644 include/acpi/acpi_lpit.h diff --git a/Documentation/acpi/lpit.txt b/Documentation/acpi/lpit.txt new file mode 100644 index 0000000..6be68c0 --- /dev/null +++ b/Documentation/acpi/lpit.txt @@ -0,0 +1,26 @@ +To enumerate platform Low Power Idle states, Intel platforms are using +“Low Power Idle Table” (LPIT). More details about this table can be +downloaded from: +http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf + +Residencies for each low power state can be read via FFH +(Function fixed hardware) or a memory mapped interface. + +On platforms supporting S0ix sleep states, there can be two types of +residencies: +- CPU PKG C10 (Read via FFH interface) +- Platform Controller Hub (PCH) SLP_S0 (Read via memory mapped interface) + +The following attributes are added dynamically to the cpuidle +sysfs attribute group: + /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us + /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us + +The "low_power_idle_cpu_residency_us" attribute shows time spent +by the CPU package in PKG C10 + +The "low_power_idle_system_residency_us" attribute shows SLP_S0 +residency, or system time spent with the SLP_S0# signal asserted. +This is the lowest possible system power state, achieved only when CPU is in +PKG C10 and all functional blocks in PCH are in a low power state. + diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 1ce52f8..4bfef0f 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -80,6 +80,11 @@ endif config ACPI_SPCR_TABLE bool +config ACPI_LPIT + bool + depends on X86_64 + default y + config ACPI_SLEEP bool depends on SUSPEND || HIBERNATION diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 90265ab..6a19bd7 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -56,6 +56,7 @@ acpi-$(CONFIG_DEBUG_FS) += debugfs.o acpi-$(CONFIG_ACPI_NUMA) += numa.o acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o acpi-y += acpi_lpat.o +acpi-$(CONFIG_ACPI_LPIT) += acpi_lpit.o acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o acpi-$(CONFIG_ACPI_WATCHDOG) += acpi_watchdog.o diff --git a/drivers/acpi/acpi_lpit.c b/drivers/acpi/acpi_lpit.c new file mode 100644 index 0000000..38d760d --- /dev/null +++ b/drivers/acpi/acpi_lpit.c @@ -0,0 +1,157 @@ + +/* + * acpi_lpit.c - LPIT table processing functions + * + * Copyright (C) 2017 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include + +struct lpit_residency_info { + struct acpi_generic_address gaddr; + u64 frequency; + void __iomem *iomem_addr; +}; + +/* Storage for an memory mapped and FFH based entries */ +static struct lpit_residency_info residency_info_mem; +static struct lpit_residency_info residency_info_ffh; + +static int lpit_read_residency_counter_us(u64 *counter, bool io_mem) +{ + int err; + + if (io_mem) { + u32 count; + + count = readl(residency_info_mem.iomem_addr); + *counter = div64_u64(count * 1000000ULL, residency_info_mem.frequency); + return 0; + } + + err = rdmsrl_safe(residency_info_ffh.gaddr.address, counter); + if (!err) { + u64 mask = GENMASK_ULL(residency_info_ffh.gaddr.bit_offset + + residency_info_ffh.gaddr. bit_width - 1, + residency_info_ffh.gaddr.bit_offset); + + *counter &= mask; + *counter >>= residency_info_ffh.gaddr.bit_offset; + *counter = div64_u64(*counter * 1000000ULL, residency_info_ffh.frequency); + return 0; + } + + return -ENODATA; +} + +static ssize_t low_power_idle_system_residency_us_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + u64 counter; + int ret; + + ret = lpit_read_residency_counter_us(&counter, true); + if (ret) + return ret; + + return sprintf(buf, "%llu\n", counter); +} +static DEVICE_ATTR_RO(low_power_idle_system_residency_us); + +static ssize_t low_power_idle_cpu_residency_us_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + u64 counter; + int ret; + + ret = lpit_read_residency_counter_us(&counter, false); + if (ret) + return ret; + + return sprintf(buf, "%llu\n", counter); +} +static DEVICE_ATTR_RO(low_power_idle_cpu_residency_us); + +int lpit_read_residency_count_address(u64 *address) +{ + if (!residency_info_mem.gaddr.address) + return -EINVAL; + + *address = residency_info_mem.gaddr.address; + + return 0; +} + +static void lpit_update_residency(struct lpit_residency_info *info, + struct acpi_lpit_native *lpit_native) +{ + info->frequency = lpit_native->counter_frequency ? + lpit_native->counter_frequency : tsc_khz * 1000; + if (!info->frequency) + info->frequency = 1; + + info->gaddr = lpit_native->residency_counter; + if (info->gaddr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + info->iomem_addr = ioremap_nocache(info->gaddr.address, + info->gaddr.bit_width / 8); + if (!info->iomem_addr) + return; + + /* Silently fail, if cpuidle attribute group is not present */ + sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj, + &dev_attr_low_power_idle_system_residency_us.attr, + "cpuidle"); + } else if (info->gaddr.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { + /* Silently fail, if cpuidle attribute group is not present */ + sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj, + &dev_attr_low_power_idle_cpu_residency_us.attr, + "cpuidle"); + } +} + +static void lpit_process(u64 begin, u64 end) +{ + while (begin + sizeof(struct acpi_lpit_native) < end) { + struct acpi_lpit_native *lpit_native = (struct acpi_lpit_native *)begin; + + if (!lpit_native->header.type && !lpit_native->header.flags) { + if (lpit_native->residency_counter.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY && + !residency_info_mem.gaddr.address) { + lpit_update_residency(&residency_info_mem, lpit_native); + } else if (lpit_native->residency_counter.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE && + !residency_info_ffh.gaddr.address) { + lpit_update_residency(&residency_info_ffh, lpit_native); + } + } + begin += lpit_native->header.length; + } +} + +void acpi_init_lpit(void) +{ + acpi_status status; + u64 lpit_begin; + struct acpi_table_lpit *lpit; + + status = acpi_get_table(ACPI_SIG_LPIT, 0, (struct acpi_table_header **)&lpit); + + if (ACPI_FAILURE(status)) + return; + + lpit_begin = (u64)lpit + sizeof(*lpit); + lpit_process(lpit_begin, lpit_begin + lpit->header.length); +} diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 602f8ff..3f05d43 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -15,6 +15,8 @@ #include #include +#include + #include #include "internal.h" @@ -2122,6 +2124,7 @@ int __init acpi_scan_init(void) acpi_int340x_thermal_init(); acpi_amba_init(); acpi_watchdog_init(); + acpi_init_lpit(); acpi_scan_add_handler(&generic_device_handler); diff --git a/include/acpi/acpi_lpit.h b/include/acpi/acpi_lpit.h new file mode 100644 index 0000000..5d5285a --- /dev/null +++ b/include/acpi/acpi_lpit.h @@ -0,0 +1,34 @@ +/* + * acpi_lpit.h - LPIT table processing functions interface + * + * Copyright (C) 2017 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef ACPI_LPIT_H +#define ACPI_LPIT_H + +#ifdef CONFIG_ACPI_LPIT + +void acpi_init_lpit(void); +int lpit_read_residency_count_address(u64 *address); + +#else + +static inline void acpi_init_lpit(void) { } + +static inline int lpit_read_residency_count_address(u64 *address) +{ + return -EINVAL; +} + +#endif +#endif