platform/x86: Support Turbo Boost Max 3.0 for non HWP systems (4ec567b8) · Commits · 戴 / test

drivers/platform/x86/Kconfig

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		@@ -1074,4 +1074,14 @@ config MLX_CPLD_PLATFORM
		This driver handles hot-plug events for the power suppliers, power
		cables and fans on the wide range Mellanox IB and Ethernet systems.

		config INTEL_TURBO_MAX_3
		bool "Intel Turbo Boost Max Technology 3.0 enumeration driver"
		depends on X86_64 && SCHED_MC_PRIO
		---help---
		This driver reads maximum performance ratio of each CPU and set up
		the scheduler priority metrics. In this way scheduler can prefer
		CPU with higher performance to schedule tasks.
		This driver is only required when the system is not using Hardware
		P-States (HWP). In HWP mode, priority can be read from ACPI tables.

		endif # X86_PLATFORM_DEVICES

drivers/platform/x86/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -76,3 +76,4 @@ obj-$(CONFIG_INTEL_TELEMETRY) += intel_telemetry_core.o \
		obj-$(CONFIG_INTEL_PMC_CORE) += intel_pmc_core.o
		obj-$(CONFIG_MLX_PLATFORM) += mlx-platform.o
		obj-$(CONFIG_MLX_CPLD_PLATFORM) += mlxcpld-hotplug.o
		obj-$(CONFIG_INTEL_TURBO_MAX_3) += intel_turbo_max_3.o

drivers/platform/x86/intel_turbo_max_3.c

0 → 100644

+152 −0

Original line number	Diff line number	Diff line
		/*
		* Intel Turbo Boost Max Technology 3.0 legacy (non HWP) enumeration driver
		* Copyright (c) 2017, Intel Corporation.
		* All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms and conditions of the GNU General Public License,
		* version 2, as published by the Free Software Foundation.
		*
		* This program is distributed in the hope 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.
		*
		*/
		#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/cpuhotplug.h>
		#include <linux/cpufeature.h>
		#include <asm/cpu_device_id.h>
		#include <asm/intel-family.h>

		#define MSR_OC_MAILBOX 0x150
		#define MSR_OC_MAILBOX_CMD_OFFSET 32
		#define MSR_OC_MAILBOX_RSP_OFFSET 32
		#define MSR_OC_MAILBOX_BUSY_BIT 63
		#define OC_MAILBOX_FC_CONTROL_CMD 0x1C

		/*
		* Typical latency to get mail box response is ~3us, It takes +3 us to
		* process reading mailbox after issuing mailbox write on a Broadwell 3.4 GHz
		* system. So for most of the time, the first mailbox read should have the
		* response, but to avoid some boundary cases retry twice.
		*/
		#define OC_MAILBOX_RETRY_COUNT 2

		static int get_oc_core_priority(unsigned int cpu)
		{
		u64 value, cmd = OC_MAILBOX_FC_CONTROL_CMD;
		int ret, i;

		/* Issue favored core read command */
		value = cmd << MSR_OC_MAILBOX_CMD_OFFSET;
		/* Set the busy bit to indicate OS is trying to issue command */
		value \|= BIT_ULL(MSR_OC_MAILBOX_BUSY_BIT);
		ret = wrmsrl_safe(MSR_OC_MAILBOX, value);
		if (ret) {
		pr_debug("cpu %d OC mailbox write failed\n", cpu);
		return ret;
		}

		for (i = 0; i < OC_MAILBOX_RETRY_COUNT; ++i) {
		ret = rdmsrl_safe(MSR_OC_MAILBOX, &value);
		if (ret) {
		pr_debug("cpu %d OC mailbox read failed\n", cpu);
		break;
		}

		if (value & BIT_ULL(MSR_OC_MAILBOX_BUSY_BIT)) {
		pr_debug("cpu %d OC mailbox still processing\n", cpu);
		ret = -EBUSY;
		continue;
		}

		if ((value >> MSR_OC_MAILBOX_RSP_OFFSET) & 0xff) {
		pr_debug("cpu %d OC mailbox cmd failed\n", cpu);
		ret = -ENXIO;
		break;
		}

		ret = value & 0xff;
		pr_debug("cpu %d max_ratio %d\n", cpu, ret);
		break;
		}

		return ret;
		}

		/*
		* The work item is needed to avoid CPU hotplug locking issues. The function
		* itmt_legacy_set_priority() is called from CPU online callback, so can't
		* call sched_set_itmt_support() from there as this function will aquire
		* hotplug locks in its path.
		*/
		static void itmt_legacy_work_fn(struct work_struct *work)
		{
		sched_set_itmt_support();
		}

		static DECLARE_WORK(sched_itmt_work, itmt_legacy_work_fn);

		static int itmt_legacy_cpu_online(unsigned int cpu)
		{
		static u32 max_highest_perf = 0, min_highest_perf = U32_MAX;
		int priority;

		priority = get_oc_core_priority(cpu);
		if (priority < 0)
		return 0;

		sched_set_itmt_core_prio(priority, cpu);

		/* Enable ITMT feature when a core with different priority is found */
		if (max_highest_perf <= min_highest_perf) {
		if (priority > max_highest_perf)
		max_highest_perf = priority;

		if (priority < min_highest_perf)
		min_highest_perf = priority;

		if (max_highest_perf > min_highest_perf)
		schedule_work(&sched_itmt_work);
		}

		return 0;
		}

		#define ICPU(model) { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }

		static const struct x86_cpu_id itmt_legacy_cpu_ids[] = {
		ICPU(INTEL_FAM6_BROADWELL_X),
		{}
		};
		MODULE_DEVICE_TABLE(x86cpu, itmt_legacy_cpu_ids);

		static int __init itmt_legacy_init(void)
		{
		const struct x86_cpu_id *id;
		int ret;

		id = x86_match_cpu(itmt_legacy_cpu_ids);
		if (!id)
		return -ENODEV;

		if (boot_cpu_has(X86_FEATURE_HWP))
		return -ENODEV;

		ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
		"platform/x86/turbo_max_3:online",
		itmt_legacy_cpu_online, NULL);
		if (ret < 0)
		return ret;

		return 0;
		}
		late_initcall(itmt_legacy_init)

		MODULE_DESCRIPTION("Intel Turbo Boost Max 3.0 enumeration driver");
		MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
		MODULE_LICENSE("GPL v2");

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