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tlb.c

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    intel_pstate.c 83.69 KiB
    // SPDX-License-Identifier: GPL-2.0-only
    /*
     * intel_pstate.c: Native P state management for Intel processors
     *
     * (C) Copyright 2012 Intel Corporation
     * Author: Dirk Brandewie <dirk.j.brandewie@intel.com>
     */
    
    #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
    
    #include <linux/kernel.h>
    #include <linux/kernel_stat.h>
    #include <linux/module.h>
    #include <linux/ktime.h>
    #include <linux/hrtimer.h>
    #include <linux/tick.h>
    #include <linux/slab.h>
    #include <linux/sched/cpufreq.h>
    #include <linux/list.h>
    #include <linux/cpu.h>
    #include <linux/cpufreq.h>
    #include <linux/sysfs.h>
    #include <linux/types.h>
    #include <linux/fs.h>
    #include <linux/acpi.h>
    #include <linux/vmalloc.h>
    #include <linux/pm_qos.h>
    #include <trace/events/power.h>
    
    #include <asm/div64.h>
    #include <asm/msr.h>
    #include <asm/cpu_device_id.h>
    #include <asm/cpufeature.h>
    #include <asm/intel-family.h>
    
    #define INTEL_PSTATE_SAMPLING_INTERVAL	(10 * NSEC_PER_MSEC)
    
    #define INTEL_CPUFREQ_TRANSITION_LATENCY	20000
    #define INTEL_CPUFREQ_TRANSITION_DELAY_HWP	5000
    #define INTEL_CPUFREQ_TRANSITION_DELAY		500
    
    #ifdef CONFIG_ACPI
    #include <acpi/processor.h>
    #include <acpi/cppc_acpi.h>
    #endif
    
    #define FRAC_BITS 8
    #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
    #define fp_toint(X) ((X) >> FRAC_BITS)
    
    #define ONE_EIGHTH_FP ((int64_t)1 << (FRAC_BITS - 3))
    
    #define EXT_BITS 6
    #define EXT_FRAC_BITS (EXT_BITS + FRAC_BITS)
    #define fp_ext_toint(X) ((X) >> EXT_FRAC_BITS)
    #define int_ext_tofp(X) ((int64_t)(X) << EXT_FRAC_BITS)
    
    static inline int32_t mul_fp(int32_t x, int32_t y)
    {
    	return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
    }
    
    static inline int32_t div_fp(s64 x, s64 y)
    {
    	return div64_s64((int64_t)x << FRAC_BITS, y);
    }
    
    static inline int ceiling_fp(int32_t x)
    {
    	int mask, ret;
    
    	ret = fp_toint(x);
    	mask = (1 << FRAC_BITS) - 1;
    	if (x & mask)
    		ret += 1;
    	return ret;
    }
    
    static inline u64 mul_ext_fp(u64 x, u64 y)
    {
    	return (x * y) >> EXT_FRAC_BITS;
    }
    
    static inline u64 div_ext_fp(u64 x, u64 y)
    {
    	return div64_u64(x << EXT_FRAC_BITS, y);
    }
    
    /**
     * struct sample -	Store performance sample
     * @core_avg_perf:	Ratio of APERF/MPERF which is the actual average
     *			performance during last sample period
     * @busy_scaled:	Scaled busy value which is used to calculate next
     *			P state. This can be different than core_avg_perf
     *			to account for cpu idle period
     * @aperf:		Difference of actual performance frequency clock count
     *			read from APERF MSR between last and current sample
     * @mperf:		Difference of maximum performance frequency clock count
     *			read from MPERF MSR between last and current sample
     * @tsc:		Difference of time stamp counter between last and
     *			current sample
     * @time:		Current time from scheduler
     *
     * This structure is used in the cpudata structure to store performance sample
     * data for choosing next P State.
     */
    struct sample {
    	int32_t core_avg_perf;
    	int32_t busy_scaled;
    	u64 aperf;
    	u64 mperf;
    	u64 tsc;
    	u64 time;
    };
    
    /**
     * struct pstate_data - Store P state data
     * @current_pstate:	Current requested P state
     * @min_pstate:		Min P state possible for this platform
     * @max_pstate:		Max P state possible for this platform
     * @max_pstate_physical:This is physical Max P state for a processor
     *			This can be higher than the max_pstate which can
     *			be limited by platform thermal design power limits
     * @perf_ctl_scaling:	PERF_CTL P-state to frequency scaling factor
     * @scaling:		Scaling factor between performance and frequency
     * @turbo_pstate:	Max Turbo P state possible for this platform
     * @min_freq:		@min_pstate frequency in cpufreq units
     * @max_freq:		@max_pstate frequency in cpufreq units
     * @turbo_freq:		@turbo_pstate frequency in cpufreq units
     *
     * Stores the per cpu model P state limits and current P state.
     */
    struct pstate_data {
    	int	current_pstate;
    	int	min_pstate;
    	int	max_pstate;
    	int	max_pstate_physical;
    	int	perf_ctl_scaling;
    	int	scaling;
    	int	turbo_pstate;
    	unsigned int min_freq;
    	unsigned int max_freq;
    	unsigned int turbo_freq;
    };
    
    /**
     * struct vid_data -	Stores voltage information data
     * @min:		VID data for this platform corresponding to
     *			the lowest P state
     * @max:		VID data corresponding to the highest P State.
     * @turbo:		VID data for turbo P state
     * @ratio:		Ratio of (vid max - vid min) /
     *			(max P state - Min P State)
     *
     * Stores the voltage data for DVFS (Dynamic Voltage and Frequency Scaling)
     * This data is used in Atom platforms, where in addition to target P state,
     * the voltage data needs to be specified to select next P State.
     */
    struct vid_data {
    	int min;
    	int max;
    	int turbo;
    	int32_t ratio;
    };
    
    /**
     * struct global_params - Global parameters, mostly tunable via sysfs.
     * @no_turbo:		Whether or not to use turbo P-states.
     * @turbo_disabled:	Whether or not turbo P-states are available at all,
     *			based on the MSR_IA32_MISC_ENABLE value and whether or
     *			not the maximum reported turbo P-state is different from
     *			the maximum reported non-turbo one.
     * @turbo_disabled_mf:	The @turbo_disabled value reflected by cpuinfo.max_freq.
     * @min_perf_pct:	Minimum capacity limit in percent of the maximum turbo
     *			P-state capacity.
     * @max_perf_pct:	Maximum capacity limit in percent of the maximum turbo
     *			P-state capacity.
     */
    struct global_params {
    	bool no_turbo;
    	bool turbo_disabled;
    	bool turbo_disabled_mf;
    	int max_perf_pct;
    	int min_perf_pct;
    };
    
    /**
     * struct cpudata -	Per CPU instance data storage
     * @cpu:		CPU number for this instance data
     * @policy:		CPUFreq policy value
     * @update_util:	CPUFreq utility callback information
     * @update_util_set:	CPUFreq utility callback is set
     * @iowait_boost:	iowait-related boost fraction
     * @last_update:	Time of the last update.
     * @pstate:		Stores P state limits for this CPU
     * @vid:		Stores VID limits for this CPU
     * @last_sample_time:	Last Sample time
     * @aperf_mperf_shift:	APERF vs MPERF counting frequency difference
     * @prev_aperf:		Last APERF value read from APERF MSR
     * @prev_mperf:		Last MPERF value read from MPERF MSR
     * @prev_tsc:		Last timestamp counter (TSC) value
     * @prev_cummulative_iowait: IO Wait time difference from last and
     *			current sample
     * @sample:		Storage for storing last Sample data
     * @min_perf_ratio:	Minimum capacity in terms of PERF or HWP ratios
     * @max_perf_ratio:	Maximum capacity in terms of PERF or HWP ratios
     * @acpi_perf_data:	Stores ACPI perf information read from _PSS
     * @valid_pss_table:	Set to true for valid ACPI _PSS entries found
     * @epp_powersave:	Last saved HWP energy performance preference
     *			(EPP) or energy performance bias (EPB),
     *			when policy switched to performance
     * @epp_policy:		Last saved policy used to set EPP/EPB
     * @epp_default:	Power on default HWP energy performance
     *			preference/bias
     * @epp_cached		Cached HWP energy-performance preference value
     * @hwp_req_cached:	Cached value of the last HWP Request MSR
     * @hwp_cap_cached:	Cached value of the last HWP Capabilities MSR
     * @last_io_update:	Last time when IO wake flag was set
     * @sched_flags:	Store scheduler flags for possible cross CPU update
     * @hwp_boost_min:	Last HWP boosted min performance
     * @suspended:		Whether or not the driver has been suspended.
     *
     * This structure stores per CPU instance data for all CPUs.
     */
    struct cpudata {
    	int cpu;
    
    	unsigned int policy;
    	struct update_util_data update_util;
    	bool   update_util_set;
    
    	struct pstate_data pstate;
    	struct vid_data vid;
    
    	u64	last_update;
    	u64	last_sample_time;
    	u64	aperf_mperf_shift;
    	u64	prev_aperf;
    	u64	prev_mperf;
    	u64	prev_tsc;
    	u64	prev_cummulative_iowait;
    	struct sample sample;
    	int32_t	min_perf_ratio;
    	int32_t	max_perf_ratio;
    #ifdef CONFIG_ACPI
    	struct acpi_processor_performance acpi_perf_data;
    	bool valid_pss_table;
    #endif
    	unsigned int iowait_boost;
    	s16 epp_powersave;
    	s16 epp_policy;
    	s16 epp_default;
    	s16 epp_cached;
    	u64 hwp_req_cached;
    	u64 hwp_cap_cached;
    	u64 last_io_update;
    	unsigned int sched_flags;
    	u32 hwp_boost_min;
    	bool suspended;
    };
    
    static struct cpudata **all_cpu_data;
    
    /**
     * struct pstate_funcs - Per CPU model specific callbacks
     * @get_max:		Callback to get maximum non turbo effective P state
     * @get_max_physical:	Callback to get maximum non turbo physical P state
     * @get_min:		Callback to get minimum P state
     * @get_turbo:		Callback to get turbo P state
     * @get_scaling:	Callback to get frequency scaling factor
     * @get_cpu_scaling:	Get frequency scaling factor for a given cpu
     * @get_aperf_mperf_shift: Callback to get the APERF vs MPERF frequency difference
     * @get_val:		Callback to convert P state to actual MSR write value
     * @get_vid:		Callback to get VID data for Atom platforms
     *
     * Core and Atom CPU models have different way to get P State limits. This
     * structure is used to store those callbacks.
     */
    struct pstate_funcs {
    	int (*get_max)(void);
    	int (*get_max_physical)(void);
    	int (*get_min)(void);
    	int (*get_turbo)(void);
    	int (*get_scaling)(void);
    	int (*get_cpu_scaling)(int cpu);
    	int (*get_aperf_mperf_shift)(void);
    	u64 (*get_val)(struct cpudata*, int pstate);
    	void (*get_vid)(struct cpudata *);
    };
    
    static struct pstate_funcs pstate_funcs __read_mostly;
    
    static int hwp_active __read_mostly;
    static int hwp_mode_bdw __read_mostly;
    static bool per_cpu_limits __read_mostly;
    static bool hwp_boost __read_mostly;
    
    static struct cpufreq_driver *intel_pstate_driver __read_mostly;
    
    #ifdef CONFIG_ACPI
    static bool acpi_ppc;
    #endif
    
    static struct global_params global;
    
    static DEFINE_MUTEX(intel_pstate_driver_lock);
    static DEFINE_MUTEX(intel_pstate_limits_lock);
    
    #ifdef CONFIG_ACPI
    
    static bool intel_pstate_acpi_pm_profile_server(void)
    {
    	if (acpi_gbl_FADT.preferred_profile == PM_ENTERPRISE_SERVER ||
    	    acpi_gbl_FADT.preferred_profile == PM_PERFORMANCE_SERVER)
    		return true;
    
    	return false;
    }
    
    static bool intel_pstate_get_ppc_enable_status(void)
    {
    	if (intel_pstate_acpi_pm_profile_server())
    		return true;
    
    	return acpi_ppc;
    }
    
    #ifdef CONFIG_ACPI_CPPC_LIB
    
    /* The work item is needed to avoid CPU hotplug locking issues */
    static void intel_pstste_sched_itmt_work_fn(struct work_struct *work)
    {
    	sched_set_itmt_support();
    }
    
    static DECLARE_WORK(sched_itmt_work, intel_pstste_sched_itmt_work_fn);
    
    static void intel_pstate_set_itmt_prio(int cpu)
    {
    	struct cppc_perf_caps cppc_perf;
    	static u32 max_highest_perf = 0, min_highest_perf = U32_MAX;
    	int ret;
    
    	ret = cppc_get_perf_caps(cpu, &cppc_perf);
    	if (ret)
    		return;
    
    	/*
    	 * The priorities can be set regardless of whether or not
    	 * sched_set_itmt_support(true) has been called and it is valid to
    	 * update them at any time after it has been called.
    	 */
    	sched_set_itmt_core_prio(cppc_perf.highest_perf, cpu);
    
    	if (max_highest_perf <= min_highest_perf) {
    		if (cppc_perf.highest_perf > max_highest_perf)
    			max_highest_perf = cppc_perf.highest_perf;
    
    		if (cppc_perf.highest_perf < min_highest_perf)
    			min_highest_perf = cppc_perf.highest_perf;
    
    		if (max_highest_perf > min_highest_perf) {
    			/*
    			 * This code can be run during CPU online under the
    			 * CPU hotplug locks, so sched_set_itmt_support()
    			 * cannot be called from here.  Queue up a work item
    			 * to invoke it.
    			 */
    			schedule_work(&sched_itmt_work);
    		}
    	}
    }
    
    static int intel_pstate_get_cppc_guaranteed(int cpu)
    {
    	struct cppc_perf_caps cppc_perf;
    	int ret;
    
    	ret = cppc_get_perf_caps(cpu, &cppc_perf);
    	if (ret)
    		return ret;
    
    	if (cppc_perf.guaranteed_perf)
    		return cppc_perf.guaranteed_perf;
    
    	return cppc_perf.nominal_perf;
    }
    
    static u32 intel_pstate_cppc_nominal(int cpu)
    {
    	u64 nominal_perf;
    
    	if (cppc_get_nominal_perf(cpu, &nominal_perf))
    		return 0;
    
    	return nominal_perf;
    }
    #else /* CONFIG_ACPI_CPPC_LIB */
    static inline void intel_pstate_set_itmt_prio(int cpu)
    {
    }
    #endif /* CONFIG_ACPI_CPPC_LIB */
    
    static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu;
    	int ret;
    	int i;
    
    	if (hwp_active) {
    		intel_pstate_set_itmt_prio(policy->cpu);
    		return;
    	}
    
    	if (!intel_pstate_get_ppc_enable_status())
    		return;
    
    	cpu = all_cpu_data[policy->cpu];
    
    	ret = acpi_processor_register_performance(&cpu->acpi_perf_data,
    						  policy->cpu);
    	if (ret)
    		return;
    
    	/*
    	 * Check if the control value in _PSS is for PERF_CTL MSR, which should
    	 * guarantee that the states returned by it map to the states in our
    	 * list directly.
    	 */
    	if (cpu->acpi_perf_data.control_register.space_id !=
    						ACPI_ADR_SPACE_FIXED_HARDWARE)
    		goto err;
    
    	/*
    	 * If there is only one entry _PSS, simply ignore _PSS and continue as
    	 * usual without taking _PSS into account
    	 */
    	if (cpu->acpi_perf_data.state_count < 2)
    		goto err;
    
    	pr_debug("CPU%u - ACPI _PSS perf data\n", policy->cpu);
    	for (i = 0; i < cpu->acpi_perf_data.state_count; i++) {
    		pr_debug("     %cP%d: %u MHz, %u mW, 0x%x\n",
    			 (i == cpu->acpi_perf_data.state ? '*' : ' '), i,
    			 (u32) cpu->acpi_perf_data.states[i].core_frequency,
    			 (u32) cpu->acpi_perf_data.states[i].power,
    			 (u32) cpu->acpi_perf_data.states[i].control);
    	}
    
    	/*
    	 * The _PSS table doesn't contain whole turbo frequency range.
    	 * This just contains +1 MHZ above the max non turbo frequency,
    	 * with control value corresponding to max turbo ratio. But
    	 * when cpufreq set policy is called, it will call with this
    	 * max frequency, which will cause a reduced performance as
    	 * this driver uses real max turbo frequency as the max
    	 * frequency. So correct this frequency in _PSS table to
    	 * correct max turbo frequency based on the turbo state.
    	 * Also need to convert to MHz as _PSS freq is in MHz.
    	 */
    	if (!global.turbo_disabled)
    		cpu->acpi_perf_data.states[0].core_frequency =
    					policy->cpuinfo.max_freq / 1000;
    	cpu->valid_pss_table = true;
    	pr_debug("_PPC limits will be enforced\n");
    
    	return;
    
     err:
    	cpu->valid_pss_table = false;
    	acpi_processor_unregister_performance(policy->cpu);
    }
    
    static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu;
    
    	cpu = all_cpu_data[policy->cpu];
    	if (!cpu->valid_pss_table)
    		return;
    
    	acpi_processor_unregister_performance(policy->cpu);
    }
    #else /* CONFIG_ACPI */
    static inline void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
    {
    }
    
    static inline void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
    {
    }
    
    static inline bool intel_pstate_acpi_pm_profile_server(void)
    {
    	return false;
    }
    #endif /* CONFIG_ACPI */
    
    #ifndef CONFIG_ACPI_CPPC_LIB
    static inline int intel_pstate_get_cppc_guaranteed(int cpu)
    {
    	return -ENOTSUPP;
    }
    #endif /* CONFIG_ACPI_CPPC_LIB */
    
    /**
     * intel_pstate_hybrid_hwp_adjust - Calibrate HWP performance levels.
     * @cpu: Target CPU.
     *
     * On hybrid processors, HWP may expose more performance levels than there are
     * P-states accessible through the PERF_CTL interface.  If that happens, the
     * scaling factor between HWP performance levels and CPU frequency will be less
     * than the scaling factor between P-state values and CPU frequency.
     *
     * In that case, adjust the CPU parameters used in computations accordingly.
     */
    static void intel_pstate_hybrid_hwp_adjust(struct cpudata *cpu)
    {
    	int perf_ctl_max_phys = cpu->pstate.max_pstate_physical;
    	int perf_ctl_scaling = cpu->pstate.perf_ctl_scaling;
    	int perf_ctl_turbo = pstate_funcs.get_turbo();
    	int turbo_freq = perf_ctl_turbo * perf_ctl_scaling;
    	int scaling = cpu->pstate.scaling;
    
    	pr_debug("CPU%d: perf_ctl_max_phys = %d\n", cpu->cpu, perf_ctl_max_phys);
    	pr_debug("CPU%d: perf_ctl_max = %d\n", cpu->cpu, pstate_funcs.get_max());
    	pr_debug("CPU%d: perf_ctl_turbo = %d\n", cpu->cpu, perf_ctl_turbo);
    	pr_debug("CPU%d: perf_ctl_scaling = %d\n", cpu->cpu, perf_ctl_scaling);
    	pr_debug("CPU%d: HWP_CAP guaranteed = %d\n", cpu->cpu, cpu->pstate.max_pstate);
    	pr_debug("CPU%d: HWP_CAP highest = %d\n", cpu->cpu, cpu->pstate.turbo_pstate);
    	pr_debug("CPU%d: HWP-to-frequency scaling factor: %d\n", cpu->cpu, scaling);
    
    	/*
    	 * If the product of the HWP performance scaling factor and the HWP_CAP
    	 * highest performance is greater than the maximum turbo frequency
    	 * corresponding to the pstate_funcs.get_turbo() return value, the
    	 * scaling factor is too high, so recompute it to make the HWP_CAP
    	 * highest performance correspond to the maximum turbo frequency.
    	 */
    	if (turbo_freq < cpu->pstate.turbo_pstate * scaling) {
    		cpu->pstate.turbo_freq = turbo_freq;
    		scaling = DIV_ROUND_UP(turbo_freq, cpu->pstate.turbo_pstate);
    		cpu->pstate.scaling = scaling;
    
    		pr_debug("CPU%d: refined HWP-to-frequency scaling factor: %d\n",
    			 cpu->cpu, scaling);
    	}
    
    	cpu->pstate.max_freq = rounddown(cpu->pstate.max_pstate * scaling,
    					 perf_ctl_scaling);
    
    	cpu->pstate.max_pstate_physical =
    			DIV_ROUND_UP(perf_ctl_max_phys * perf_ctl_scaling,
    				     scaling);
    
    	cpu->pstate.min_freq = cpu->pstate.min_pstate * perf_ctl_scaling;
    	/*
    	 * Cast the min P-state value retrieved via pstate_funcs.get_min() to
    	 * the effective range of HWP performance levels.
    	 */
    	cpu->pstate.min_pstate = DIV_ROUND_UP(cpu->pstate.min_freq, scaling);
    }
    
    static inline void update_turbo_state(void)
    {
    	u64 misc_en;
    	struct cpudata *cpu;
    
    	cpu = all_cpu_data[0];
    	rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
    	global.turbo_disabled =
    		(misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
    		 cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
    }
    
    static int min_perf_pct_min(void)
    {
    	struct cpudata *cpu = all_cpu_data[0];
    	int turbo_pstate = cpu->pstate.turbo_pstate;
    
    	return turbo_pstate ?
    		(cpu->pstate.min_pstate * 100 / turbo_pstate) : 0;
    }
    
    static s16 intel_pstate_get_epb(struct cpudata *cpu_data)
    {
    	u64 epb;
    	int ret;
    
    	if (!boot_cpu_has(X86_FEATURE_EPB))
    		return -ENXIO;
    
    	ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_IA32_ENERGY_PERF_BIAS, &epb);
    	if (ret)
    		return (s16)ret;
    
    	return (s16)(epb & 0x0f);
    }
    
    static s16 intel_pstate_get_epp(struct cpudata *cpu_data, u64 hwp_req_data)
    {
    	s16 epp;
    
    	if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
    		/*
    		 * When hwp_req_data is 0, means that caller didn't read
    		 * MSR_HWP_REQUEST, so need to read and get EPP.
    		 */
    		if (!hwp_req_data) {
    			epp = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST,
    					    &hwp_req_data);
    			if (epp)
    				return epp;
    		}
    		epp = (hwp_req_data >> 24) & 0xff;
    	} else {
    		/* When there is no EPP present, HWP uses EPB settings */
    		epp = intel_pstate_get_epb(cpu_data);
    	}
    
    	return epp;
    }
    
    static int intel_pstate_set_epb(int cpu, s16 pref)
    {
    	u64 epb;
    	int ret;
    
    	if (!boot_cpu_has(X86_FEATURE_EPB))
    		return -ENXIO;
    
    	ret = rdmsrl_on_cpu(cpu, MSR_IA32_ENERGY_PERF_BIAS, &epb);
    	if (ret)
    		return ret;
    
    	epb = (epb & ~0x0f) | pref;
    	wrmsrl_on_cpu(cpu, MSR_IA32_ENERGY_PERF_BIAS, epb);
    
    	return 0;
    }
    
    /*
     * EPP/EPB display strings corresponding to EPP index in the
     * energy_perf_strings[]
     *	index		String
     *-------------------------------------
     *	0		default
     *	1		performance
     *	2		balance_performance
     *	3		balance_power
     *	4		power
     */
    static const char * const energy_perf_strings[] = {
    	"default",
    	"performance",
    	"balance_performance",
    	"balance_power",
    	"power",
    	NULL
    };
    static const unsigned int epp_values[] = {
    	HWP_EPP_PERFORMANCE,
    	HWP_EPP_BALANCE_PERFORMANCE,
    	HWP_EPP_BALANCE_POWERSAVE,
    	HWP_EPP_POWERSAVE
    };
    
    static int intel_pstate_get_energy_pref_index(struct cpudata *cpu_data, int *raw_epp)
    {
    	s16 epp;
    	int index = -EINVAL;
    
    	*raw_epp = 0;
    	epp = intel_pstate_get_epp(cpu_data, 0);
    	if (epp < 0)
    		return epp;
    
    	if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
    		if (epp == HWP_EPP_PERFORMANCE)
    			return 1;
    		if (epp == HWP_EPP_BALANCE_PERFORMANCE)
    			return 2;
    		if (epp == HWP_EPP_BALANCE_POWERSAVE)
    			return 3;
    		if (epp == HWP_EPP_POWERSAVE)
    			return 4;
    		*raw_epp = epp;
    		return 0;
    	} else if (boot_cpu_has(X86_FEATURE_EPB)) {
    		/*
    		 * Range:
    		 *	0x00-0x03	:	Performance
    		 *	0x04-0x07	:	Balance performance
    		 *	0x08-0x0B	:	Balance power
    		 *	0x0C-0x0F	:	Power
    		 * The EPB is a 4 bit value, but our ranges restrict the
    		 * value which can be set. Here only using top two bits
    		 * effectively.
    		 */
    		index = (epp >> 2) + 1;
    	}
    
    	return index;
    }
    
    static int intel_pstate_set_epp(struct cpudata *cpu, u32 epp)
    {
    	int ret;
    
    	/*
    	 * Use the cached HWP Request MSR value, because in the active mode the
    	 * register itself may be updated by intel_pstate_hwp_boost_up() or
    	 * intel_pstate_hwp_boost_down() at any time.
    	 */
    	u64 value = READ_ONCE(cpu->hwp_req_cached);
    
    	value &= ~GENMASK_ULL(31, 24);
    	value |= (u64)epp << 24;
    	/*
    	 * The only other updater of hwp_req_cached in the active mode,
    	 * intel_pstate_hwp_set(), is called under the same lock as this
    	 * function, so it cannot run in parallel with the update below.
    	 */
    	WRITE_ONCE(cpu->hwp_req_cached, value);
    	ret = wrmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, value);
    	if (!ret)
    		cpu->epp_cached = epp;
    
    	return ret;
    }
    
    static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
    					      int pref_index, bool use_raw,
    					      u32 raw_epp)
    {
    	int epp = -EINVAL;
    	int ret;
    
    	if (!pref_index)
    		epp = cpu_data->epp_default;
    
    	if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
    		if (use_raw)
    			epp = raw_epp;
    		else if (epp == -EINVAL)
    			epp = epp_values[pref_index - 1];
    
    		/*
    		 * To avoid confusion, refuse to set EPP to any values different
    		 * from 0 (performance) if the current policy is "performance",
    		 * because those values would be overridden.
    		 */
    		if (epp > 0 && cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
    			return -EBUSY;
    
    		ret = intel_pstate_set_epp(cpu_data, epp);
    	} else {
    		if (epp == -EINVAL)
    			epp = (pref_index - 1) << 2;
    		ret = intel_pstate_set_epb(cpu_data->cpu, epp);
    	}
    
    	return ret;
    }
    
    static ssize_t show_energy_performance_available_preferences(
    				struct cpufreq_policy *policy, char *buf)
    {
    	int i = 0;
    	int ret = 0;
    
    	while (energy_perf_strings[i] != NULL)
    		ret += sprintf(&buf[ret], "%s ", energy_perf_strings[i++]);
    
    	ret += sprintf(&buf[ret], "\n");
    
    	return ret;
    }
    
    cpufreq_freq_attr_ro(energy_performance_available_preferences);
    
    static struct cpufreq_driver intel_pstate;
    
    static ssize_t store_energy_performance_preference(
    		struct cpufreq_policy *policy, const char *buf, size_t count)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    	char str_preference[21];
    	bool raw = false;
    	ssize_t ret;
    	u32 epp = 0;
    
    	ret = sscanf(buf, "%20s", str_preference);
    	if (ret != 1)
    		return -EINVAL;
    
    	ret = match_string(energy_perf_strings, -1, str_preference);
    	if (ret < 0) {
    		if (!boot_cpu_has(X86_FEATURE_HWP_EPP))
    			return ret;
    
    		ret = kstrtouint(buf, 10, &epp);
    		if (ret)
    			return ret;
    
    		if (epp > 255)
    			return -EINVAL;
    
    		raw = true;
    	}
    
    	/*
    	 * This function runs with the policy R/W semaphore held, which
    	 * guarantees that the driver pointer will not change while it is
    	 * running.
    	 */
    	if (!intel_pstate_driver)
    		return -EAGAIN;
    
    	mutex_lock(&intel_pstate_limits_lock);
    
    	if (intel_pstate_driver == &intel_pstate) {
    		ret = intel_pstate_set_energy_pref_index(cpu, ret, raw, epp);
    	} else {
    		/*
    		 * In the passive mode the governor needs to be stopped on the
    		 * target CPU before the EPP update and restarted after it,
    		 * which is super-heavy-weight, so make sure it is worth doing
    		 * upfront.
    		 */
    		if (!raw)
    			epp = ret ? epp_values[ret - 1] : cpu->epp_default;
    
    		if (cpu->epp_cached != epp) {
    			int err;
    
    			cpufreq_stop_governor(policy);
    			ret = intel_pstate_set_epp(cpu, epp);
    			err = cpufreq_start_governor(policy);
    			if (!ret)
    				ret = err;
    		}
    	}
    
    	mutex_unlock(&intel_pstate_limits_lock);
    
    	return ret ?: count;
    }
    
    static ssize_t show_energy_performance_preference(
    				struct cpufreq_policy *policy, char *buf)
    {
    	struct cpudata *cpu_data = all_cpu_data[policy->cpu];
    	int preference, raw_epp;
    
    	preference = intel_pstate_get_energy_pref_index(cpu_data, &raw_epp);
    	if (preference < 0)
    		return preference;
    
    	if (raw_epp)
    		return  sprintf(buf, "%d\n", raw_epp);
    	else
    		return  sprintf(buf, "%s\n", energy_perf_strings[preference]);
    }
    
    cpufreq_freq_attr_rw(energy_performance_preference);
    
    static ssize_t show_base_frequency(struct cpufreq_policy *policy, char *buf)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    	int ratio, freq;
    
    	ratio = intel_pstate_get_cppc_guaranteed(policy->cpu);
    	if (ratio <= 0) {
    		u64 cap;
    
    		rdmsrl_on_cpu(policy->cpu, MSR_HWP_CAPABILITIES, &cap);
    		ratio = HWP_GUARANTEED_PERF(cap);
    	}
    
    	freq = ratio * cpu->pstate.scaling;
    	if (cpu->pstate.scaling != cpu->pstate.perf_ctl_scaling)
    		freq = rounddown(freq, cpu->pstate.perf_ctl_scaling);
    
    	return sprintf(buf, "%d\n", freq);
    }
    
    cpufreq_freq_attr_ro(base_frequency);
    
    static struct freq_attr *hwp_cpufreq_attrs[] = {
    	&energy_performance_preference,
    	&energy_performance_available_preferences,
    	&base_frequency,
    	NULL,
    };
    
    static void __intel_pstate_get_hwp_cap(struct cpudata *cpu)
    {
    	u64 cap;
    
    	rdmsrl_on_cpu(cpu->cpu, MSR_HWP_CAPABILITIES, &cap);
    	WRITE_ONCE(cpu->hwp_cap_cached, cap);
    	cpu->pstate.max_pstate = HWP_GUARANTEED_PERF(cap);
    	cpu->pstate.turbo_pstate = HWP_HIGHEST_PERF(cap);
    }
    
    static void intel_pstate_get_hwp_cap(struct cpudata *cpu)
    {
    	int scaling = cpu->pstate.scaling;
    
    	__intel_pstate_get_hwp_cap(cpu);
    
    	cpu->pstate.max_freq = cpu->pstate.max_pstate * scaling;
    	cpu->pstate.turbo_freq = cpu->pstate.turbo_pstate * scaling;
    	if (scaling != cpu->pstate.perf_ctl_scaling) {
    		int perf_ctl_scaling = cpu->pstate.perf_ctl_scaling;
    
    		cpu->pstate.max_freq = rounddown(cpu->pstate.max_freq,
    						 perf_ctl_scaling);
    		cpu->pstate.turbo_freq = rounddown(cpu->pstate.turbo_freq,
    						   perf_ctl_scaling);
    	}
    }
    
    static void intel_pstate_hwp_set(unsigned int cpu)
    {
    	struct cpudata *cpu_data = all_cpu_data[cpu];
    	int max, min;
    	u64 value;
    	s16 epp;
    
    	max = cpu_data->max_perf_ratio;
    	min = cpu_data->min_perf_ratio;
    
    	if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
    		min = max;
    
    	rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
    
    	value &= ~HWP_MIN_PERF(~0L);
    	value |= HWP_MIN_PERF(min);
    
    	value &= ~HWP_MAX_PERF(~0L);
    	value |= HWP_MAX_PERF(max);
    
    	if (cpu_data->epp_policy == cpu_data->policy)
    		goto skip_epp;
    
    	cpu_data->epp_policy = cpu_data->policy;
    
    	if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) {
    		epp = intel_pstate_get_epp(cpu_data, value);
    		cpu_data->epp_powersave = epp;
    		/* If EPP read was failed, then don't try to write */
    		if (epp < 0)
    			goto skip_epp;
    
    		epp = 0;
    	} else {
    		/* skip setting EPP, when saved value is invalid */
    		if (cpu_data->epp_powersave < 0)
    			goto skip_epp;
    
    		/*
    		 * No need to restore EPP when it is not zero. This
    		 * means:
    		 *  - Policy is not changed
    		 *  - user has manually changed
    		 *  - Error reading EPB
    		 */
    		epp = intel_pstate_get_epp(cpu_data, value);
    		if (epp)
    			goto skip_epp;
    
    		epp = cpu_data->epp_powersave;
    	}
    	if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
    		value &= ~GENMASK_ULL(31, 24);
    		value |= (u64)epp << 24;
    	} else {
    		intel_pstate_set_epb(cpu, epp);
    	}
    skip_epp:
    	WRITE_ONCE(cpu_data->hwp_req_cached, value);
    	wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
    }
    
    static void intel_pstate_hwp_offline(struct cpudata *cpu)
    {
    	u64 value = READ_ONCE(cpu->hwp_req_cached);
    	int min_perf;
    
    	if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
    		/*
    		 * In case the EPP has been set to "performance" by the
    		 * active mode "performance" scaling algorithm, replace that
    		 * temporary value with the cached EPP one.
    		 */
    		value &= ~GENMASK_ULL(31, 24);
    		value |= HWP_ENERGY_PERF_PREFERENCE(cpu->epp_cached);
    		WRITE_ONCE(cpu->hwp_req_cached, value);
    	}
    
    	value &= ~GENMASK_ULL(31, 0);
    	min_perf = HWP_LOWEST_PERF(READ_ONCE(cpu->hwp_cap_cached));
    
    	/* Set hwp_max = hwp_min */
    	value |= HWP_MAX_PERF(min_perf);
    	value |= HWP_MIN_PERF(min_perf);
    
    	/* Set EPP to min */
    	if (boot_cpu_has(X86_FEATURE_HWP_EPP))
    		value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE);
    
    	wrmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, value);
    }
    
    #define POWER_CTL_EE_ENABLE	1
    #define POWER_CTL_EE_DISABLE	2
    
    static int power_ctl_ee_state;
    
    static void set_power_ctl_ee_state(bool input)
    {
    	u64 power_ctl;
    
    	mutex_lock(&intel_pstate_driver_lock);
    	rdmsrl(MSR_IA32_POWER_CTL, power_ctl);
    	if (input) {
    		power_ctl &= ~BIT(MSR_IA32_POWER_CTL_BIT_EE);
    		power_ctl_ee_state = POWER_CTL_EE_ENABLE;
    	} else {
    		power_ctl |= BIT(MSR_IA32_POWER_CTL_BIT_EE);
    		power_ctl_ee_state = POWER_CTL_EE_DISABLE;
    	}
    	wrmsrl(MSR_IA32_POWER_CTL, power_ctl);
    	mutex_unlock(&intel_pstate_driver_lock);
    }
    
    static void intel_pstate_hwp_enable(struct cpudata *cpudata);
    
    static void intel_pstate_hwp_reenable(struct cpudata *cpu)
    {
    	intel_pstate_hwp_enable(cpu);
    	wrmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, READ_ONCE(cpu->hwp_req_cached));
    }
    
    static int intel_pstate_suspend(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    
    	pr_debug("CPU %d suspending\n", cpu->cpu);
    
    	cpu->suspended = true;
    
    	return 0;
    }
    
    static int intel_pstate_resume(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    
    	pr_debug("CPU %d resuming\n", cpu->cpu);
    
    	/* Only restore if the system default is changed */
    	if (power_ctl_ee_state == POWER_CTL_EE_ENABLE)
    		set_power_ctl_ee_state(true);
    	else if (power_ctl_ee_state == POWER_CTL_EE_DISABLE)
    		set_power_ctl_ee_state(false);
    
    	if (cpu->suspended && hwp_active) {
    		mutex_lock(&intel_pstate_limits_lock);
    
    		/* Re-enable HWP, because "online" has not done that. */
    		intel_pstate_hwp_reenable(cpu);
    
    		mutex_unlock(&intel_pstate_limits_lock);
    	}
    
    	cpu->suspended = false;
    
    	return 0;
    }
    
    static void intel_pstate_update_policies(void)
    {
    	int cpu;
    
    	for_each_possible_cpu(cpu)
    		cpufreq_update_policy(cpu);
    }
    
    static void intel_pstate_update_max_freq(unsigned int cpu)
    {
    	struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
    	struct cpudata *cpudata;
    
    	if (!policy)
    		return;
    
    	cpudata = all_cpu_data[cpu];
    	policy->cpuinfo.max_freq = global.turbo_disabled_mf ?
    			cpudata->pstate.max_freq : cpudata->pstate.turbo_freq;
    
    	refresh_frequency_limits(policy);
    
    	cpufreq_cpu_release(policy);
    }
    
    static void intel_pstate_update_limits(unsigned int cpu)
    {
    	mutex_lock(&intel_pstate_driver_lock);
    
    	update_turbo_state();
    	/*
    	 * If turbo has been turned on or off globally, policy limits for
    	 * all CPUs need to be updated to reflect that.
    	 */
    	if (global.turbo_disabled_mf != global.turbo_disabled) {
    		global.turbo_disabled_mf = global.turbo_disabled;
    		arch_set_max_freq_ratio(global.turbo_disabled);
    		for_each_possible_cpu(cpu)
    			intel_pstate_update_max_freq(cpu);
    	} else {
    		cpufreq_update_policy(cpu);
    	}
    
    	mutex_unlock(&intel_pstate_driver_lock);
    }
    
    /************************** sysfs begin ************************/
    #define show_one(file_name, object)					\
    	static ssize_t show_##file_name					\
    	(struct kobject *kobj, struct kobj_attribute *attr, char *buf)	\
    	{								\
    		return sprintf(buf, "%u\n", global.object);		\
    	}
    
    static ssize_t intel_pstate_show_status(char *buf);
    static int intel_pstate_update_status(const char *buf, size_t size);
    
    static ssize_t show_status(struct kobject *kobj,
    			   struct kobj_attribute *attr, char *buf)
    {
    	ssize_t ret;
    
    	mutex_lock(&intel_pstate_driver_lock);
    	ret = intel_pstate_show_status(buf);
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return ret;
    }
    
    static ssize_t store_status(struct kobject *a, struct kobj_attribute *b,
    			    const char *buf, size_t count)
    {
    	char *p = memchr(buf, '\n', count);
    	int ret;
    
    	mutex_lock(&intel_pstate_driver_lock);
    	ret = intel_pstate_update_status(buf, p ? p - buf : count);
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return ret < 0 ? ret : count;
    }
    
    static ssize_t show_turbo_pct(struct kobject *kobj,
    				struct kobj_attribute *attr, char *buf)
    {
    	struct cpudata *cpu;
    	int total, no_turbo, turbo_pct;
    	uint32_t turbo_fp;
    
    	mutex_lock(&intel_pstate_driver_lock);
    
    	if (!intel_pstate_driver) {
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EAGAIN;
    	}
    
    	cpu = all_cpu_data[0];
    
    	total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
    	no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
    	turbo_fp = div_fp(no_turbo, total);
    	turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
    
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return sprintf(buf, "%u\n", turbo_pct);
    }
    
    static ssize_t show_num_pstates(struct kobject *kobj,
    				struct kobj_attribute *attr, char *buf)
    {
    	struct cpudata *cpu;
    	int total;
    
    	mutex_lock(&intel_pstate_driver_lock);
    
    	if (!intel_pstate_driver) {
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EAGAIN;
    	}
    
    	cpu = all_cpu_data[0];
    	total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
    
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return sprintf(buf, "%u\n", total);
    }
    
    static ssize_t show_no_turbo(struct kobject *kobj,
    			     struct kobj_attribute *attr, char *buf)
    {
    	ssize_t ret;
    
    	mutex_lock(&intel_pstate_driver_lock);
    
    	if (!intel_pstate_driver) {
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EAGAIN;
    	}
    
    	update_turbo_state();
    	if (global.turbo_disabled)
    		ret = sprintf(buf, "%u\n", global.turbo_disabled);
    	else
    		ret = sprintf(buf, "%u\n", global.no_turbo);
    
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return ret;
    }
    
    static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b,
    			      const char *buf, size_t count)
    {
    	unsigned int input;
    	int ret;
    
    	ret = sscanf(buf, "%u", &input);
    	if (ret != 1)
    		return -EINVAL;
    
    	mutex_lock(&intel_pstate_driver_lock);
    
    	if (!intel_pstate_driver) {
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EAGAIN;
    	}
    
    	mutex_lock(&intel_pstate_limits_lock);
    
    	update_turbo_state();
    	if (global.turbo_disabled) {
    		pr_notice_once("Turbo disabled by BIOS or unavailable on processor\n");
    		mutex_unlock(&intel_pstate_limits_lock);
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EPERM;
    	}
    
    	global.no_turbo = clamp_t(int, input, 0, 1);
    
    	if (global.no_turbo) {
    		struct cpudata *cpu = all_cpu_data[0];
    		int pct = cpu->pstate.max_pstate * 100 / cpu->pstate.turbo_pstate;
    
    		/* Squash the global minimum into the permitted range. */
    		if (global.min_perf_pct > pct)
    			global.min_perf_pct = pct;
    	}
    
    	mutex_unlock(&intel_pstate_limits_lock);
    
    	intel_pstate_update_policies();
    
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return count;
    }
    
    static void update_qos_request(enum freq_qos_req_type type)
    {
    	struct freq_qos_request *req;
    	struct cpufreq_policy *policy;
    	int i;
    
    	for_each_possible_cpu(i) {
    		struct cpudata *cpu = all_cpu_data[i];
    		unsigned int freq, perf_pct;
    
    		policy = cpufreq_cpu_get(i);
    		if (!policy)
    			continue;
    
    		req = policy->driver_data;
    		cpufreq_cpu_put(policy);
    
    		if (!req)
    			continue;
    
    		if (hwp_active)
    			intel_pstate_get_hwp_cap(cpu);
    
    		if (type == FREQ_QOS_MIN) {
    			perf_pct = global.min_perf_pct;
    		} else {
    			req++;
    			perf_pct = global.max_perf_pct;
    		}
    
    		freq = DIV_ROUND_UP(cpu->pstate.turbo_freq * perf_pct, 100);
    
    		if (freq_qos_update_request(req, freq) < 0)
    			pr_warn("Failed to update freq constraint: CPU%d\n", i);
    	}
    }
    
    static ssize_t store_max_perf_pct(struct kobject *a, struct kobj_attribute *b,
    				  const char *buf, size_t count)
    {
    	unsigned int input;
    	int ret;
    
    	ret = sscanf(buf, "%u", &input);
    	if (ret != 1)
    		return -EINVAL;
    
    	mutex_lock(&intel_pstate_driver_lock);
    
    	if (!intel_pstate_driver) {
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EAGAIN;
    	}
    
    	mutex_lock(&intel_pstate_limits_lock);
    
    	global.max_perf_pct = clamp_t(int, input, global.min_perf_pct, 100);
    
    	mutex_unlock(&intel_pstate_limits_lock);
    
    	if (intel_pstate_driver == &intel_pstate)
    		intel_pstate_update_policies();
    	else
    		update_qos_request(FREQ_QOS_MAX);
    
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return count;
    }
    
    static ssize_t store_min_perf_pct(struct kobject *a, struct kobj_attribute *b,
    				  const char *buf, size_t count)
    {
    	unsigned int input;
    	int ret;
    
    	ret = sscanf(buf, "%u", &input);
    	if (ret != 1)
    		return -EINVAL;
    
    	mutex_lock(&intel_pstate_driver_lock);
    
    	if (!intel_pstate_driver) {
    		mutex_unlock(&intel_pstate_driver_lock);
    		return -EAGAIN;
    	}
    
    	mutex_lock(&intel_pstate_limits_lock);
    
    	global.min_perf_pct = clamp_t(int, input,
    				      min_perf_pct_min(), global.max_perf_pct);
    
    	mutex_unlock(&intel_pstate_limits_lock);
    
    	if (intel_pstate_driver == &intel_pstate)
    		intel_pstate_update_policies();
    	else
    		update_qos_request(FREQ_QOS_MIN);
    
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return count;
    }
    
    static ssize_t show_hwp_dynamic_boost(struct kobject *kobj,
    				struct kobj_attribute *attr, char *buf)
    {
    	return sprintf(buf, "%u\n", hwp_boost);
    }
    
    static ssize_t store_hwp_dynamic_boost(struct kobject *a,
    				       struct kobj_attribute *b,
    				       const char *buf, size_t count)
    {
    	unsigned int input;
    	int ret;
    
    	ret = kstrtouint(buf, 10, &input);
    	if (ret)
    		return ret;
    
    	mutex_lock(&intel_pstate_driver_lock);
    	hwp_boost = !!input;
    	intel_pstate_update_policies();
    	mutex_unlock(&intel_pstate_driver_lock);
    
    	return count;
    }
    
    static ssize_t show_energy_efficiency(struct kobject *kobj, struct kobj_attribute *attr,
    				      char *buf)
    {
    	u64 power_ctl;
    	int enable;
    
    	rdmsrl(MSR_IA32_POWER_CTL, power_ctl);
    	enable = !!(power_ctl & BIT(MSR_IA32_POWER_CTL_BIT_EE));
    	return sprintf(buf, "%d\n", !enable);
    }
    
    static ssize_t store_energy_efficiency(struct kobject *a, struct kobj_attribute *b,
    				       const char *buf, size_t count)
    {
    	bool input;
    	int ret;
    
    	ret = kstrtobool(buf, &input);
    	if (ret)
    		return ret;
    
    	set_power_ctl_ee_state(input);
    
    	return count;
    }
    
    show_one(max_perf_pct, max_perf_pct);
    show_one(min_perf_pct, min_perf_pct);
    
    define_one_global_rw(status);
    define_one_global_rw(no_turbo);
    define_one_global_rw(max_perf_pct);
    define_one_global_rw(min_perf_pct);
    define_one_global_ro(turbo_pct);
    define_one_global_ro(num_pstates);
    define_one_global_rw(hwp_dynamic_boost);
    define_one_global_rw(energy_efficiency);
    
    static struct attribute *intel_pstate_attributes[] = {
    	&status.attr,
    	&no_turbo.attr,
    	NULL
    };
    
    static const struct attribute_group intel_pstate_attr_group = {
    	.attrs = intel_pstate_attributes,
    };
    
    static const struct x86_cpu_id intel_pstate_cpu_ee_disable_ids[];
    
    static struct kobject *intel_pstate_kobject;
    
    static void __init intel_pstate_sysfs_expose_params(void)
    {
    	int rc;
    
    	intel_pstate_kobject = kobject_create_and_add("intel_pstate",
    						&cpu_subsys.dev_root->kobj);
    	if (WARN_ON(!intel_pstate_kobject))
    		return;
    
    	rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group);
    	if (WARN_ON(rc))
    		return;
    
    	if (!boot_cpu_has(X86_FEATURE_HYBRID_CPU)) {
    		rc = sysfs_create_file(intel_pstate_kobject, &turbo_pct.attr);
    		WARN_ON(rc);
    
    		rc = sysfs_create_file(intel_pstate_kobject, &num_pstates.attr);
    		WARN_ON(rc);
    	}
    
    	/*
    	 * If per cpu limits are enforced there are no global limits, so
    	 * return without creating max/min_perf_pct attributes
    	 */
    	if (per_cpu_limits)
    		return;
    
    	rc = sysfs_create_file(intel_pstate_kobject, &max_perf_pct.attr);
    	WARN_ON(rc);
    
    	rc = sysfs_create_file(intel_pstate_kobject, &min_perf_pct.attr);
    	WARN_ON(rc);
    
    	if (x86_match_cpu(intel_pstate_cpu_ee_disable_ids)) {
    		rc = sysfs_create_file(intel_pstate_kobject, &energy_efficiency.attr);
    		WARN_ON(rc);
    	}
    }
    
    static void __init intel_pstate_sysfs_remove(void)
    {
    	if (!intel_pstate_kobject)
    		return;
    
    	sysfs_remove_group(intel_pstate_kobject, &intel_pstate_attr_group);
    
    	if (!boot_cpu_has(X86_FEATURE_HYBRID_CPU)) {
    		sysfs_remove_file(intel_pstate_kobject, &num_pstates.attr);
    		sysfs_remove_file(intel_pstate_kobject, &turbo_pct.attr);
    	}
    
    	if (!per_cpu_limits) {
    		sysfs_remove_file(intel_pstate_kobject, &max_perf_pct.attr);
    		sysfs_remove_file(intel_pstate_kobject, &min_perf_pct.attr);
    
    		if (x86_match_cpu(intel_pstate_cpu_ee_disable_ids))
    			sysfs_remove_file(intel_pstate_kobject, &energy_efficiency.attr);
    	}
    
    	kobject_put(intel_pstate_kobject);
    }
    
    static void intel_pstate_sysfs_expose_hwp_dynamic_boost(void)
    {
    	int rc;
    
    	if (!hwp_active)
    		return;
    
    	rc = sysfs_create_file(intel_pstate_kobject, &hwp_dynamic_boost.attr);
    	WARN_ON_ONCE(rc);
    }
    
    static void intel_pstate_sysfs_hide_hwp_dynamic_boost(void)
    {
    	if (!hwp_active)
    		return;
    
    	sysfs_remove_file(intel_pstate_kobject, &hwp_dynamic_boost.attr);
    }
    
    /************************** sysfs end ************************/
    
    static void intel_pstate_hwp_enable(struct cpudata *cpudata)
    {
    	/* First disable HWP notification interrupt as we don't process them */
    	if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY))
    		wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00);
    
    	wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);
    	if (cpudata->epp_default == -EINVAL)
    		cpudata->epp_default = intel_pstate_get_epp(cpudata, 0);
    }
    
    static int atom_get_min_pstate(void)
    {
    	u64 value;
    
    	rdmsrl(MSR_ATOM_CORE_RATIOS, value);
    	return (value >> 8) & 0x7F;
    }
    
    static int atom_get_max_pstate(void)
    {
    	u64 value;
    
    	rdmsrl(MSR_ATOM_CORE_RATIOS, value);
    	return (value >> 16) & 0x7F;
    }
    
    static int atom_get_turbo_pstate(void)
    {
    	u64 value;
    
    	rdmsrl(MSR_ATOM_CORE_TURBO_RATIOS, value);
    	return value & 0x7F;
    }
    
    static u64 atom_get_val(struct cpudata *cpudata, int pstate)
    {
    	u64 val;
    	int32_t vid_fp;
    	u32 vid;
    
    	val = (u64)pstate << 8;
    	if (global.no_turbo && !global.turbo_disabled)
    		val |= (u64)1 << 32;
    
    	vid_fp = cpudata->vid.min + mul_fp(
    		int_tofp(pstate - cpudata->pstate.min_pstate),
    		cpudata->vid.ratio);
    
    	vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
    	vid = ceiling_fp(vid_fp);
    
    	if (pstate > cpudata->pstate.max_pstate)
    		vid = cpudata->vid.turbo;
    
    	return val | vid;
    }
    
    static int silvermont_get_scaling(void)
    {
    	u64 value;
    	int i;
    	/* Defined in Table 35-6 from SDM (Sept 2015) */
    	static int silvermont_freq_table[] = {
    		83300, 100000, 133300, 116700, 80000};
    
    	rdmsrl(MSR_FSB_FREQ, value);
    	i = value & 0x7;
    	WARN_ON(i > 4);
    
    	return silvermont_freq_table[i];
    }
    
    static int airmont_get_scaling(void)
    {
    	u64 value;
    	int i;
    	/* Defined in Table 35-10 from SDM (Sept 2015) */
    	static int airmont_freq_table[] = {
    		83300, 100000, 133300, 116700, 80000,
    		93300, 90000, 88900, 87500};
    
    	rdmsrl(MSR_FSB_FREQ, value);
    	i = value & 0xF;
    	WARN_ON(i > 8);
    
    	return airmont_freq_table[i];
    }
    
    static void atom_get_vid(struct cpudata *cpudata)
    {
    	u64 value;
    
    	rdmsrl(MSR_ATOM_CORE_VIDS, value);
    	cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
    	cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
    	cpudata->vid.ratio = div_fp(
    		cpudata->vid.max - cpudata->vid.min,
    		int_tofp(cpudata->pstate.max_pstate -
    			cpudata->pstate.min_pstate));
    
    	rdmsrl(MSR_ATOM_CORE_TURBO_VIDS, value);
    	cpudata->vid.turbo = value & 0x7f;
    }
    
    static int core_get_min_pstate(void)
    {
    	u64 value;
    
    	rdmsrl(MSR_PLATFORM_INFO, value);
    	return (value >> 40) & 0xFF;
    }
    
    static int core_get_max_pstate_physical(void)
    {
    	u64 value;
    
    	rdmsrl(MSR_PLATFORM_INFO, value);
    	return (value >> 8) & 0xFF;
    }
    
    static int core_get_tdp_ratio(u64 plat_info)
    {
    	/* Check how many TDP levels present */
    	if (plat_info & 0x600000000) {
    		u64 tdp_ctrl;
    		u64 tdp_ratio;
    		int tdp_msr;
    		int err;
    
    		/* Get the TDP level (0, 1, 2) to get ratios */
    		err = rdmsrl_safe(MSR_CONFIG_TDP_CONTROL, &tdp_ctrl);
    		if (err)
    			return err;
    
    		/* TDP MSR are continuous starting at 0x648 */
    		tdp_msr = MSR_CONFIG_TDP_NOMINAL + (tdp_ctrl & 0x03);
    		err = rdmsrl_safe(tdp_msr, &tdp_ratio);
    		if (err)
    			return err;
    
    		/* For level 1 and 2, bits[23:16] contain the ratio */
    		if (tdp_ctrl & 0x03)
    			tdp_ratio >>= 16;
    
    		tdp_ratio &= 0xff; /* ratios are only 8 bits long */
    		pr_debug("tdp_ratio %x\n", (int)tdp_ratio);
    
    		return (int)tdp_ratio;
    	}
    
    	return -ENXIO;
    }
    
    static int core_get_max_pstate(void)
    {
    	u64 tar;
    	u64 plat_info;
    	int max_pstate;
    	int tdp_ratio;
    	int err;
    
    	rdmsrl(MSR_PLATFORM_INFO, plat_info);
    	max_pstate = (plat_info >> 8) & 0xFF;
    
    	tdp_ratio = core_get_tdp_ratio(plat_info);
    	if (tdp_ratio <= 0)
    		return max_pstate;
    
    	if (hwp_active) {
    		/* Turbo activation ratio is not used on HWP platforms */
    		return tdp_ratio;
    	}
    
    	err = rdmsrl_safe(MSR_TURBO_ACTIVATION_RATIO, &tar);
    	if (!err) {
    		int tar_levels;
    
    		/* Do some sanity checking for safety */
    		tar_levels = tar & 0xff;
    		if (tdp_ratio - 1 == tar_levels) {
    			max_pstate = tar_levels;
    			pr_debug("max_pstate=TAC %x\n", max_pstate);
    		}
    	}
    
    	return max_pstate;
    }
    
    static int core_get_turbo_pstate(void)
    {
    	u64 value;
    	int nont, ret;
    
    	rdmsrl(MSR_TURBO_RATIO_LIMIT, value);
    	nont = core_get_max_pstate();
    	ret = (value) & 255;
    	if (ret <= nont)
    		ret = nont;
    	return ret;
    }
    
    static inline int core_get_scaling(void)
    {
    	return 100000;
    }
    
    static u64 core_get_val(struct cpudata *cpudata, int pstate)
    {
    	u64 val;
    
    	val = (u64)pstate << 8;
    	if (global.no_turbo && !global.turbo_disabled)
    		val |= (u64)1 << 32;
    
    	return val;
    }
    
    static int knl_get_aperf_mperf_shift(void)
    {
    	return 10;
    }
    
    static int knl_get_turbo_pstate(void)
    {
    	u64 value;
    	int nont, ret;
    
    	rdmsrl(MSR_TURBO_RATIO_LIMIT, value);
    	nont = core_get_max_pstate();
    	ret = (((value) >> 8) & 0xFF);
    	if (ret <= nont)
    		ret = nont;
    	return ret;
    }
    
    #ifdef CONFIG_ACPI_CPPC_LIB
    static u32 hybrid_ref_perf;
    
    static int hybrid_get_cpu_scaling(int cpu)
    {
    	return DIV_ROUND_UP(core_get_scaling() * hybrid_ref_perf,
    			    intel_pstate_cppc_nominal(cpu));
    }
    
    static void intel_pstate_cppc_set_cpu_scaling(void)
    {
    	u32 min_nominal_perf = U32_MAX;
    	int cpu;
    
    	for_each_present_cpu(cpu) {
    		u32 nominal_perf = intel_pstate_cppc_nominal(cpu);
    
    		if (nominal_perf && nominal_perf < min_nominal_perf)
    			min_nominal_perf = nominal_perf;
    	}
    
    	if (min_nominal_perf < U32_MAX) {
    		hybrid_ref_perf = min_nominal_perf;
    		pstate_funcs.get_cpu_scaling = hybrid_get_cpu_scaling;
    	}
    }
    #else
    static inline void intel_pstate_cppc_set_cpu_scaling(void)
    {
    }
    #endif /* CONFIG_ACPI_CPPC_LIB */
    
    static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
    {
    	trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
    	cpu->pstate.current_pstate = pstate;
    	/*
    	 * Generally, there is no guarantee that this code will always run on
    	 * the CPU being updated, so force the register update to run on the
    	 * right CPU.
    	 */
    	wrmsrl_on_cpu(cpu->cpu, MSR_IA32_PERF_CTL,
    		      pstate_funcs.get_val(cpu, pstate));
    }
    
    static void intel_pstate_set_min_pstate(struct cpudata *cpu)
    {
    	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
    }
    
    static void intel_pstate_max_within_limits(struct cpudata *cpu)
    {
    	int pstate = max(cpu->pstate.min_pstate, cpu->max_perf_ratio);
    
    	update_turbo_state();
    	intel_pstate_set_pstate(cpu, pstate);
    }
    
    static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
    {
    	int perf_ctl_max_phys = pstate_funcs.get_max_physical();
    	int perf_ctl_scaling = pstate_funcs.get_scaling();
    
    	cpu->pstate.min_pstate = pstate_funcs.get_min();
    	cpu->pstate.max_pstate_physical = perf_ctl_max_phys;
    	cpu->pstate.perf_ctl_scaling = perf_ctl_scaling;
    
    	if (hwp_active && !hwp_mode_bdw) {
    		__intel_pstate_get_hwp_cap(cpu);
    
    		if (pstate_funcs.get_cpu_scaling) {
    			cpu->pstate.scaling = pstate_funcs.get_cpu_scaling(cpu->cpu);
    			if (cpu->pstate.scaling != perf_ctl_scaling)
    				intel_pstate_hybrid_hwp_adjust(cpu);
    		} else {
    			cpu->pstate.scaling = perf_ctl_scaling;
    		}
    	} else {
    		cpu->pstate.scaling = perf_ctl_scaling;
    		cpu->pstate.max_pstate = pstate_funcs.get_max();
    		cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
    	}
    
    	if (cpu->pstate.scaling == perf_ctl_scaling) {
    		cpu->pstate.min_freq = cpu->pstate.min_pstate * perf_ctl_scaling;
    		cpu->pstate.max_freq = cpu->pstate.max_pstate * perf_ctl_scaling;
    		cpu->pstate.turbo_freq = cpu->pstate.turbo_pstate * perf_ctl_scaling;
    	}
    
    	if (pstate_funcs.get_aperf_mperf_shift)
    		cpu->aperf_mperf_shift = pstate_funcs.get_aperf_mperf_shift();
    
    	if (pstate_funcs.get_vid)
    		pstate_funcs.get_vid(cpu);
    
    	intel_pstate_set_min_pstate(cpu);
    }
    
    /*
     * Long hold time will keep high perf limits for long time,
     * which negatively impacts perf/watt for some workloads,
     * like specpower. 3ms is based on experiements on some
     * workoads.
     */
    static int hwp_boost_hold_time_ns = 3 * NSEC_PER_MSEC;
    
    static inline void intel_pstate_hwp_boost_up(struct cpudata *cpu)
    {
    	u64 hwp_req = READ_ONCE(cpu->hwp_req_cached);
    	u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached);
    	u32 max_limit = (hwp_req & 0xff00) >> 8;
    	u32 min_limit = (hwp_req & 0xff);
    	u32 boost_level1;
    
    	/*
    	 * Cases to consider (User changes via sysfs or boot time):
    	 * If, P0 (Turbo max) = P1 (Guaranteed max) = min:
    	 *	No boost, return.
    	 * If, P0 (Turbo max) > P1 (Guaranteed max) = min:
    	 *     Should result in one level boost only for P0.
    	 * If, P0 (Turbo max) = P1 (Guaranteed max) > min:
    	 *     Should result in two level boost:
    	 *         (min + p1)/2 and P1.
    	 * If, P0 (Turbo max) > P1 (Guaranteed max) > min:
    	 *     Should result in three level boost:
    	 *        (min + p1)/2, P1 and P0.
    	 */
    
    	/* If max and min are equal or already at max, nothing to boost */
    	if (max_limit == min_limit || cpu->hwp_boost_min >= max_limit)
    		return;
    
    	if (!cpu->hwp_boost_min)
    		cpu->hwp_boost_min = min_limit;
    
    	/* level at half way mark between min and guranteed */
    	boost_level1 = (HWP_GUARANTEED_PERF(hwp_cap) + min_limit) >> 1;
    
    	if (cpu->hwp_boost_min < boost_level1)
    		cpu->hwp_boost_min = boost_level1;
    	else if (cpu->hwp_boost_min < HWP_GUARANTEED_PERF(hwp_cap))
    		cpu->hwp_boost_min = HWP_GUARANTEED_PERF(hwp_cap);
    	else if (cpu->hwp_boost_min == HWP_GUARANTEED_PERF(hwp_cap) &&
    		 max_limit != HWP_GUARANTEED_PERF(hwp_cap))
    		cpu->hwp_boost_min = max_limit;
    	else
    		return;
    
    	hwp_req = (hwp_req & ~GENMASK_ULL(7, 0)) | cpu->hwp_boost_min;
    	wrmsrl(MSR_HWP_REQUEST, hwp_req);
    	cpu->last_update = cpu->sample.time;
    }
    
    static inline void intel_pstate_hwp_boost_down(struct cpudata *cpu)
    {
    	if (cpu->hwp_boost_min) {
    		bool expired;
    
    		/* Check if we are idle for hold time to boost down */
    		expired = time_after64(cpu->sample.time, cpu->last_update +
    				       hwp_boost_hold_time_ns);
    		if (expired) {
    			wrmsrl(MSR_HWP_REQUEST, cpu->hwp_req_cached);
    			cpu->hwp_boost_min = 0;
    		}
    	}
    	cpu->last_update = cpu->sample.time;
    }
    
    static inline void intel_pstate_update_util_hwp_local(struct cpudata *cpu,
    						      u64 time)
    {
    	cpu->sample.time = time;
    
    	if (cpu->sched_flags & SCHED_CPUFREQ_IOWAIT) {
    		bool do_io = false;
    
    		cpu->sched_flags = 0;
    		/*
    		 * Set iowait_boost flag and update time. Since IO WAIT flag
    		 * is set all the time, we can't just conclude that there is
    		 * some IO bound activity is scheduled on this CPU with just
    		 * one occurrence. If we receive at least two in two
    		 * consecutive ticks, then we treat as boost candidate.
    		 */
    		if (time_before64(time, cpu->last_io_update + 2 * TICK_NSEC))
    			do_io = true;
    
    		cpu->last_io_update = time;
    
    		if (do_io)
    			intel_pstate_hwp_boost_up(cpu);
    
    	} else {
    		intel_pstate_hwp_boost_down(cpu);
    	}
    }
    
    static inline void intel_pstate_update_util_hwp(struct update_util_data *data,
    						u64 time, unsigned int flags)
    {
    	struct cpudata *cpu = container_of(data, struct cpudata, update_util);
    
    	cpu->sched_flags |= flags;
    
    	if (smp_processor_id() == cpu->cpu)
    		intel_pstate_update_util_hwp_local(cpu, time);
    }
    
    static inline void intel_pstate_calc_avg_perf(struct cpudata *cpu)
    {
    	struct sample *sample = &cpu->sample;
    
    	sample->core_avg_perf = div_ext_fp(sample->aperf, sample->mperf);
    }
    
    static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time)
    {
    	u64 aperf, mperf;
    	unsigned long flags;
    	u64 tsc;
    
    	local_irq_save(flags);
    	rdmsrl(MSR_IA32_APERF, aperf);
    	rdmsrl(MSR_IA32_MPERF, mperf);
    	tsc = rdtsc();
    	if (cpu->prev_mperf == mperf || cpu->prev_tsc == tsc) {
    		local_irq_restore(flags);
    		return false;
    	}
    	local_irq_restore(flags);
    
    	cpu->last_sample_time = cpu->sample.time;
    	cpu->sample.time = time;
    	cpu->sample.aperf = aperf;
    	cpu->sample.mperf = mperf;
    	cpu->sample.tsc =  tsc;
    	cpu->sample.aperf -= cpu->prev_aperf;
    	cpu->sample.mperf -= cpu->prev_mperf;
    	cpu->sample.tsc -= cpu->prev_tsc;
    
    	cpu->prev_aperf = aperf;
    	cpu->prev_mperf = mperf;
    	cpu->prev_tsc = tsc;
    	/*
    	 * First time this function is invoked in a given cycle, all of the
    	 * previous sample data fields are equal to zero or stale and they must
    	 * be populated with meaningful numbers for things to work, so assume
    	 * that sample.time will always be reset before setting the utilization
    	 * update hook and make the caller skip the sample then.
    	 */
    	if (cpu->last_sample_time) {
    		intel_pstate_calc_avg_perf(cpu);
    		return true;
    	}
    	return false;
    }
    
    static inline int32_t get_avg_frequency(struct cpudata *cpu)
    {
    	return mul_ext_fp(cpu->sample.core_avg_perf, cpu_khz);
    }
    
    static inline int32_t get_avg_pstate(struct cpudata *cpu)
    {
    	return mul_ext_fp(cpu->pstate.max_pstate_physical,
    			  cpu->sample.core_avg_perf);
    }
    
    static inline int32_t get_target_pstate(struct cpudata *cpu)
    {
    	struct sample *sample = &cpu->sample;
    	int32_t busy_frac;
    	int target, avg_pstate;
    
    	busy_frac = div_fp(sample->mperf << cpu->aperf_mperf_shift,
    			   sample->tsc);
    
    	if (busy_frac < cpu->iowait_boost)
    		busy_frac = cpu->iowait_boost;
    
    	sample->busy_scaled = busy_frac * 100;
    
    	target = global.no_turbo || global.turbo_disabled ?
    			cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
    	target += target >> 2;
    	target = mul_fp(target, busy_frac);
    	if (target < cpu->pstate.min_pstate)
    		target = cpu->pstate.min_pstate;
    
    	/*
    	 * If the average P-state during the previous cycle was higher than the
    	 * current target, add 50% of the difference to the target to reduce
    	 * possible performance oscillations and offset possible performance
    	 * loss related to moving the workload from one CPU to another within
    	 * a package/module.
    	 */
    	avg_pstate = get_avg_pstate(cpu);
    	if (avg_pstate > target)
    		target += (avg_pstate - target) >> 1;
    
    	return target;
    }
    
    static int intel_pstate_prepare_request(struct cpudata *cpu, int pstate)
    {
    	int min_pstate = max(cpu->pstate.min_pstate, cpu->min_perf_ratio);
    	int max_pstate = max(min_pstate, cpu->max_perf_ratio);
    
    	return clamp_t(int, pstate, min_pstate, max_pstate);
    }
    
    static void intel_pstate_update_pstate(struct cpudata *cpu, int pstate)
    {
    	if (pstate == cpu->pstate.current_pstate)
    		return;
    
    	cpu->pstate.current_pstate = pstate;
    	wrmsrl(MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate));
    }
    
    static void intel_pstate_adjust_pstate(struct cpudata *cpu)
    {
    	int from = cpu->pstate.current_pstate;
    	struct sample *sample;
    	int target_pstate;
    
    	update_turbo_state();
    
    	target_pstate = get_target_pstate(cpu);
    	target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
    	trace_cpu_frequency(target_pstate * cpu->pstate.scaling, cpu->cpu);
    	intel_pstate_update_pstate(cpu, target_pstate);
    
    	sample = &cpu->sample;
    	trace_pstate_sample(mul_ext_fp(100, sample->core_avg_perf),
    		fp_toint(sample->busy_scaled),
    		from,
    		cpu->pstate.current_pstate,
    		sample->mperf,
    		sample->aperf,
    		sample->tsc,
    		get_avg_frequency(cpu),
    		fp_toint(cpu->iowait_boost * 100));
    }
    
    static void intel_pstate_update_util(struct update_util_data *data, u64 time,
    				     unsigned int flags)
    {
    	struct cpudata *cpu = container_of(data, struct cpudata, update_util);
    	u64 delta_ns;
    
    	/* Don't allow remote callbacks */
    	if (smp_processor_id() != cpu->cpu)
    		return;
    
    	delta_ns = time - cpu->last_update;
    	if (flags & SCHED_CPUFREQ_IOWAIT) {
    		/* Start over if the CPU may have been idle. */
    		if (delta_ns > TICK_NSEC) {
    			cpu->iowait_boost = ONE_EIGHTH_FP;
    		} else if (cpu->iowait_boost >= ONE_EIGHTH_FP) {
    			cpu->iowait_boost <<= 1;
    			if (cpu->iowait_boost > int_tofp(1))
    				cpu->iowait_boost = int_tofp(1);
    		} else {
    			cpu->iowait_boost = ONE_EIGHTH_FP;
    		}
    	} else if (cpu->iowait_boost) {
    		/* Clear iowait_boost if the CPU may have been idle. */
    		if (delta_ns > TICK_NSEC)
    			cpu->iowait_boost = 0;
    		else
    			cpu->iowait_boost >>= 1;
    	}
    	cpu->last_update = time;
    	delta_ns = time - cpu->sample.time;
    	if ((s64)delta_ns < INTEL_PSTATE_SAMPLING_INTERVAL)
    		return;
    
    	if (intel_pstate_sample(cpu, time))
    		intel_pstate_adjust_pstate(cpu);
    }
    
    static struct pstate_funcs core_funcs = {
    	.get_max = core_get_max_pstate,
    	.get_max_physical = core_get_max_pstate_physical,
    	.get_min = core_get_min_pstate,
    	.get_turbo = core_get_turbo_pstate,
    	.get_scaling = core_get_scaling,
    	.get_val = core_get_val,
    };
    
    static const struct pstate_funcs silvermont_funcs = {
    	.get_max = atom_get_max_pstate,
    	.get_max_physical = atom_get_max_pstate,
    	.get_min = atom_get_min_pstate,
    	.get_turbo = atom_get_turbo_pstate,
    	.get_val = atom_get_val,
    	.get_scaling = silvermont_get_scaling,
    	.get_vid = atom_get_vid,
    };
    
    static const struct pstate_funcs airmont_funcs = {
    	.get_max = atom_get_max_pstate,
    	.get_max_physical = atom_get_max_pstate,
    	.get_min = atom_get_min_pstate,
    	.get_turbo = atom_get_turbo_pstate,
    	.get_val = atom_get_val,
    	.get_scaling = airmont_get_scaling,
    	.get_vid = atom_get_vid,
    };
    
    static const struct pstate_funcs knl_funcs = {
    	.get_max = core_get_max_pstate,
    	.get_max_physical = core_get_max_pstate_physical,
    	.get_min = core_get_min_pstate,
    	.get_turbo = knl_get_turbo_pstate,
    	.get_aperf_mperf_shift = knl_get_aperf_mperf_shift,
    	.get_scaling = core_get_scaling,
    	.get_val = core_get_val,
    };
    
    #define X86_MATCH(model, policy)					 \
    	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, INTEL_FAM6_##model, \
    					   X86_FEATURE_APERFMPERF, &policy)
    
    static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
    	X86_MATCH(SANDYBRIDGE,		core_funcs),
    	X86_MATCH(SANDYBRIDGE_X,	core_funcs),
    	X86_MATCH(ATOM_SILVERMONT,	silvermont_funcs),
    	X86_MATCH(IVYBRIDGE,		core_funcs),
    	X86_MATCH(HASWELL,		core_funcs),
    	X86_MATCH(BROADWELL,		core_funcs),
    	X86_MATCH(IVYBRIDGE_X,		core_funcs),
    	X86_MATCH(HASWELL_X,		core_funcs),
    	X86_MATCH(HASWELL_L,		core_funcs),
    	X86_MATCH(HASWELL_G,		core_funcs),
    	X86_MATCH(BROADWELL_G,		core_funcs),
    	X86_MATCH(ATOM_AIRMONT,		airmont_funcs),
    	X86_MATCH(SKYLAKE_L,		core_funcs),
    	X86_MATCH(BROADWELL_X,		core_funcs),
    	X86_MATCH(SKYLAKE,		core_funcs),
    	X86_MATCH(BROADWELL_D,		core_funcs),
    	X86_MATCH(XEON_PHI_KNL,		knl_funcs),
    	X86_MATCH(XEON_PHI_KNM,		knl_funcs),
    	X86_MATCH(ATOM_GOLDMONT,	core_funcs),
    	X86_MATCH(ATOM_GOLDMONT_PLUS,	core_funcs),
    	X86_MATCH(SKYLAKE_X,		core_funcs),
    	X86_MATCH(COMETLAKE,		core_funcs),
    	X86_MATCH(ICELAKE_X,		core_funcs),
    	{}
    };
    MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
    
    static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] __initconst = {
    	X86_MATCH(BROADWELL_D,		core_funcs),
    	X86_MATCH(BROADWELL_X,		core_funcs),
    	X86_MATCH(SKYLAKE_X,		core_funcs),
    	{}
    };
    
    static const struct x86_cpu_id intel_pstate_cpu_ee_disable_ids[] = {
    	X86_MATCH(KABYLAKE,		core_funcs),
    	{}
    };
    
    static const struct x86_cpu_id intel_pstate_hwp_boost_ids[] = {
    	X86_MATCH(SKYLAKE_X,		core_funcs),
    	X86_MATCH(SKYLAKE,		core_funcs),
    	{}
    };
    
    static int intel_pstate_init_cpu(unsigned int cpunum)
    {
    	struct cpudata *cpu;
    
    	cpu = all_cpu_data[cpunum];
    
    	if (!cpu) {
    		cpu = kzalloc(sizeof(*cpu), GFP_KERNEL);
    		if (!cpu)
    			return -ENOMEM;
    
    		all_cpu_data[cpunum] = cpu;
    
    		cpu->cpu = cpunum;
    
    		cpu->epp_default = -EINVAL;
    
    		if (hwp_active) {
    			const struct x86_cpu_id *id;
    
    			intel_pstate_hwp_enable(cpu);
    
    			id = x86_match_cpu(intel_pstate_hwp_boost_ids);
    			if (id && intel_pstate_acpi_pm_profile_server())
    				hwp_boost = true;
    		}
    	} else if (hwp_active) {
    		/*
    		 * Re-enable HWP in case this happens after a resume from ACPI
    		 * S3 if the CPU was offline during the whole system/resume
    		 * cycle.
    		 */
    		intel_pstate_hwp_reenable(cpu);
    	}
    
    	cpu->epp_powersave = -EINVAL;
    	cpu->epp_policy = 0;
    
    	intel_pstate_get_cpu_pstates(cpu);
    
    	pr_debug("controlling: cpu %d\n", cpunum);
    
    	return 0;
    }
    
    static void intel_pstate_set_update_util_hook(unsigned int cpu_num)
    {
    	struct cpudata *cpu = all_cpu_data[cpu_num];
    
    	if (hwp_active && !hwp_boost)
    		return;
    
    	if (cpu->update_util_set)
    		return;
    
    	/* Prevent intel_pstate_update_util() from using stale data. */
    	cpu->sample.time = 0;
    	cpufreq_add_update_util_hook(cpu_num, &cpu->update_util,
    				     (hwp_active ?
    				      intel_pstate_update_util_hwp :
    				      intel_pstate_update_util));
    	cpu->update_util_set = true;
    }
    
    static void intel_pstate_clear_update_util_hook(unsigned int cpu)
    {
    	struct cpudata *cpu_data = all_cpu_data[cpu];
    
    	if (!cpu_data->update_util_set)
    		return;
    
    	cpufreq_remove_update_util_hook(cpu);
    	cpu_data->update_util_set = false;
    	synchronize_rcu();
    }
    
    static int intel_pstate_get_max_freq(struct cpudata *cpu)
    {
    	return global.turbo_disabled || global.no_turbo ?
    			cpu->pstate.max_freq : cpu->pstate.turbo_freq;
    }
    
    static void intel_pstate_update_perf_limits(struct cpudata *cpu,
    					    unsigned int policy_min,
    					    unsigned int policy_max)
    {
    	int perf_ctl_scaling = cpu->pstate.perf_ctl_scaling;
    	int32_t max_policy_perf, min_policy_perf;
    
    	max_policy_perf = policy_max / perf_ctl_scaling;
    	if (policy_max == policy_min) {
    		min_policy_perf = max_policy_perf;
    	} else {
    		min_policy_perf = policy_min / perf_ctl_scaling;
    		min_policy_perf = clamp_t(int32_t, min_policy_perf,
    					  0, max_policy_perf);
    	}
    
    	/*
    	 * HWP needs some special consideration, because HWP_REQUEST uses
    	 * abstract values to represent performance rather than pure ratios.
    	 */
    	if (hwp_active) {
    		intel_pstate_get_hwp_cap(cpu);
    
    		if (cpu->pstate.scaling != perf_ctl_scaling) {
    			int scaling = cpu->pstate.scaling;
    			int freq;
    
    			freq = max_policy_perf * perf_ctl_scaling;
    			max_policy_perf = DIV_ROUND_UP(freq, scaling);
    			freq = min_policy_perf * perf_ctl_scaling;
    			min_policy_perf = DIV_ROUND_UP(freq, scaling);
    		}
    	}
    
    	pr_debug("cpu:%d min_policy_perf:%d max_policy_perf:%d\n",
    		 cpu->cpu, min_policy_perf, max_policy_perf);
    
    	/* Normalize user input to [min_perf, max_perf] */
    	if (per_cpu_limits) {
    		cpu->min_perf_ratio = min_policy_perf;
    		cpu->max_perf_ratio = max_policy_perf;
    	} else {
    		int turbo_max = cpu->pstate.turbo_pstate;
    		int32_t global_min, global_max;
    
    		/* Global limits are in percent of the maximum turbo P-state. */
    		global_max = DIV_ROUND_UP(turbo_max * global.max_perf_pct, 100);
    		global_min = DIV_ROUND_UP(turbo_max * global.min_perf_pct, 100);
    		global_min = clamp_t(int32_t, global_min, 0, global_max);
    
    		pr_debug("cpu:%d global_min:%d global_max:%d\n", cpu->cpu,
    			 global_min, global_max);
    
    		cpu->min_perf_ratio = max(min_policy_perf, global_min);
    		cpu->min_perf_ratio = min(cpu->min_perf_ratio, max_policy_perf);
    		cpu->max_perf_ratio = min(max_policy_perf, global_max);
    		cpu->max_perf_ratio = max(min_policy_perf, cpu->max_perf_ratio);
    
    		/* Make sure min_perf <= max_perf */
    		cpu->min_perf_ratio = min(cpu->min_perf_ratio,
    					  cpu->max_perf_ratio);
    
    	}
    	pr_debug("cpu:%d max_perf_ratio:%d min_perf_ratio:%d\n", cpu->cpu,
    		 cpu->max_perf_ratio,
    		 cpu->min_perf_ratio);
    }
    
    static int intel_pstate_set_policy(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu;
    
    	if (!policy->cpuinfo.max_freq)
    		return -ENODEV;
    
    	pr_debug("set_policy cpuinfo.max %u policy->max %u\n",
    		 policy->cpuinfo.max_freq, policy->max);
    
    	cpu = all_cpu_data[policy->cpu];
    	cpu->policy = policy->policy;
    
    	mutex_lock(&intel_pstate_limits_lock);
    
    	intel_pstate_update_perf_limits(cpu, policy->min, policy->max);
    
    	if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) {
    		/*
    		 * NOHZ_FULL CPUs need this as the governor callback may not
    		 * be invoked on them.
    		 */
    		intel_pstate_clear_update_util_hook(policy->cpu);
    		intel_pstate_max_within_limits(cpu);
    	} else {
    		intel_pstate_set_update_util_hook(policy->cpu);
    	}
    
    	if (hwp_active) {
    		/*
    		 * When hwp_boost was active before and dynamically it
    		 * was turned off, in that case we need to clear the
    		 * update util hook.
    		 */
    		if (!hwp_boost)
    			intel_pstate_clear_update_util_hook(policy->cpu);
    		intel_pstate_hwp_set(policy->cpu);
    	}
    
    	mutex_unlock(&intel_pstate_limits_lock);
    
    	return 0;
    }
    
    static void intel_pstate_adjust_policy_max(struct cpudata *cpu,
    					   struct cpufreq_policy_data *policy)
    {
    	if (!hwp_active &&
    	    cpu->pstate.max_pstate_physical > cpu->pstate.max_pstate &&
    	    policy->max < policy->cpuinfo.max_freq &&
    	    policy->max > cpu->pstate.max_freq) {
    		pr_debug("policy->max > max non turbo frequency\n");
    		policy->max = policy->cpuinfo.max_freq;
    	}
    }
    
    static void intel_pstate_verify_cpu_policy(struct cpudata *cpu,
    					   struct cpufreq_policy_data *policy)
    {
    	int max_freq;
    
    	update_turbo_state();
    	if (hwp_active) {
    		intel_pstate_get_hwp_cap(cpu);
    		max_freq = global.no_turbo || global.turbo_disabled ?
    				cpu->pstate.max_freq : cpu->pstate.turbo_freq;
    	} else {
    		max_freq = intel_pstate_get_max_freq(cpu);
    	}
    	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, max_freq);
    
    	intel_pstate_adjust_policy_max(cpu, policy);
    }
    
    static int intel_pstate_verify_policy(struct cpufreq_policy_data *policy)
    {
    	intel_pstate_verify_cpu_policy(all_cpu_data[policy->cpu], policy);
    
    	return 0;
    }
    
    static int intel_cpufreq_cpu_offline(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    
    	pr_debug("CPU %d going offline\n", cpu->cpu);
    
    	if (cpu->suspended)
    		return 0;
    
    	/*
    	 * If the CPU is an SMT thread and it goes offline with the performance
    	 * settings different from the minimum, it will prevent its sibling
    	 * from getting to lower performance levels, so force the minimum
    	 * performance on CPU offline to prevent that from happening.
    	 */
    	if (hwp_active)
    		intel_pstate_hwp_offline(cpu);
    	else
    		intel_pstate_set_min_pstate(cpu);
    
    	intel_pstate_exit_perf_limits(policy);
    
    	return 0;
    }
    
    static int intel_pstate_cpu_online(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    
    	pr_debug("CPU %d going online\n", cpu->cpu);
    
    	intel_pstate_init_acpi_perf_limits(policy);
    
    	if (hwp_active) {
    		/*
    		 * Re-enable HWP and clear the "suspended" flag to let "resume"
    		 * know that it need not do that.
    		 */
    		intel_pstate_hwp_reenable(cpu);
    		cpu->suspended = false;
    	}
    
    	return 0;
    }
    
    static int intel_pstate_cpu_offline(struct cpufreq_policy *policy)
    {
    	intel_pstate_clear_update_util_hook(policy->cpu);
    
    	return intel_cpufreq_cpu_offline(policy);
    }
    
    static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
    {
    	pr_debug("CPU %d exiting\n", policy->cpu);
    
    	policy->fast_switch_possible = false;
    
    	return 0;
    }
    
    static int __intel_pstate_cpu_init(struct cpufreq_policy *policy)
    {
    	struct cpudata *cpu;
    	int rc;
    
    	rc = intel_pstate_init_cpu(policy->cpu);
    	if (rc)
    		return rc;
    
    	cpu = all_cpu_data[policy->cpu];
    
    	cpu->max_perf_ratio = 0xFF;
    	cpu->min_perf_ratio = 0;
    
    	/* cpuinfo and default policy values */
    	policy->cpuinfo.min_freq = cpu->pstate.min_freq;
    	update_turbo_state();
    	global.turbo_disabled_mf = global.turbo_disabled;
    	policy->cpuinfo.max_freq = global.turbo_disabled ?
    			cpu->pstate.max_freq : cpu->pstate.turbo_freq;
    
    	policy->min = policy->cpuinfo.min_freq;
    	policy->max = policy->cpuinfo.max_freq;
    
    	intel_pstate_init_acpi_perf_limits(policy);
    
    	policy->fast_switch_possible = true;
    
    	return 0;
    }
    
    static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
    {
    	int ret = __intel_pstate_cpu_init(policy);
    
    	if (ret)
    		return ret;
    
    	/*
    	 * Set the policy to powersave to provide a valid fallback value in case
    	 * the default cpufreq governor is neither powersave nor performance.
    	 */
    	policy->policy = CPUFREQ_POLICY_POWERSAVE;
    
    	if (hwp_active) {
    		struct cpudata *cpu = all_cpu_data[policy->cpu];
    
    		cpu->epp_cached = intel_pstate_get_epp(cpu, 0);
    	}
    
    	return 0;
    }
    
    static struct cpufreq_driver intel_pstate = {
    	.flags		= CPUFREQ_CONST_LOOPS,
    	.verify		= intel_pstate_verify_policy,
    	.setpolicy	= intel_pstate_set_policy,
    	.suspend	= intel_pstate_suspend,
    	.resume		= intel_pstate_resume,
    	.init		= intel_pstate_cpu_init,
    	.exit		= intel_pstate_cpu_exit,
    	.offline	= intel_pstate_cpu_offline,
    	.online		= intel_pstate_cpu_online,
    	.update_limits	= intel_pstate_update_limits,
    	.name		= "intel_pstate",
    };
    
    static int intel_cpufreq_verify_policy(struct cpufreq_policy_data *policy)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    
    	intel_pstate_verify_cpu_policy(cpu, policy);
    	intel_pstate_update_perf_limits(cpu, policy->min, policy->max);
    
    	return 0;
    }
    
    /* Use of trace in passive mode:
     *
     * In passive mode the trace core_busy field (also known as the
     * performance field, and lablelled as such on the graphs; also known as
     * core_avg_perf) is not needed and so is re-assigned to indicate if the
     * driver call was via the normal or fast switch path. Various graphs
     * output from the intel_pstate_tracer.py utility that include core_busy
     * (or performance or core_avg_perf) have a fixed y-axis from 0 to 100%,
     * so we use 10 to indicate the normal path through the driver, and
     * 90 to indicate the fast switch path through the driver.
     * The scaled_busy field is not used, and is set to 0.
     */
    
    #define	INTEL_PSTATE_TRACE_TARGET 10
    #define	INTEL_PSTATE_TRACE_FAST_SWITCH 90
    
    static void intel_cpufreq_trace(struct cpudata *cpu, unsigned int trace_type, int old_pstate)
    {
    	struct sample *sample;
    
    	if (!trace_pstate_sample_enabled())
    		return;
    
    	if (!intel_pstate_sample(cpu, ktime_get()))
    		return;
    
    	sample = &cpu->sample;
    	trace_pstate_sample(trace_type,
    		0,
    		old_pstate,
    		cpu->pstate.current_pstate,
    		sample->mperf,
    		sample->aperf,
    		sample->tsc,
    		get_avg_frequency(cpu),
    		fp_toint(cpu->iowait_boost * 100));
    }
    
    static void intel_cpufreq_hwp_update(struct cpudata *cpu, u32 min, u32 max,
    				     u32 desired, bool fast_switch)
    {
    	u64 prev = READ_ONCE(cpu->hwp_req_cached), value = prev;
    
    	value &= ~HWP_MIN_PERF(~0L);
    	value |= HWP_MIN_PERF(min);
    
    	value &= ~HWP_MAX_PERF(~0L);
    	value |= HWP_MAX_PERF(max);
    
    	value &= ~HWP_DESIRED_PERF(~0L);
    	value |= HWP_DESIRED_PERF(desired);
    
    	if (value == prev)
    		return;
    
    	WRITE_ONCE(cpu->hwp_req_cached, value);
    	if (fast_switch)
    		wrmsrl(MSR_HWP_REQUEST, value);
    	else
    		wrmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, value);
    }
    
    static void intel_cpufreq_perf_ctl_update(struct cpudata *cpu,
    					  u32 target_pstate, bool fast_switch)
    {
    	if (fast_switch)
    		wrmsrl(MSR_IA32_PERF_CTL,
    		       pstate_funcs.get_val(cpu, target_pstate));
    	else
    		wrmsrl_on_cpu(cpu->cpu, MSR_IA32_PERF_CTL,
    			      pstate_funcs.get_val(cpu, target_pstate));
    }
    
    static int intel_cpufreq_update_pstate(struct cpufreq_policy *policy,
    				       int target_pstate, bool fast_switch)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    	int old_pstate = cpu->pstate.current_pstate;
    
    	target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
    	if (hwp_active) {
    		int max_pstate = policy->strict_target ?
    					target_pstate : cpu->max_perf_ratio;
    
    		intel_cpufreq_hwp_update(cpu, target_pstate, max_pstate, 0,
    					 fast_switch);
    	} else if (target_pstate != old_pstate) {
    		intel_cpufreq_perf_ctl_update(cpu, target_pstate, fast_switch);
    	}
    
    	cpu->pstate.current_pstate = target_pstate;
    
    	intel_cpufreq_trace(cpu, fast_switch ? INTEL_PSTATE_TRACE_FAST_SWITCH :
    			    INTEL_PSTATE_TRACE_TARGET, old_pstate);
    
    	return target_pstate;
    }
    
    static int intel_cpufreq_target(struct cpufreq_policy *policy,
    				unsigned int target_freq,
    				unsigned int relation)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    	struct cpufreq_freqs freqs;
    	int target_pstate;
    
    	update_turbo_state();
    
    	freqs.old = policy->cur;
    	freqs.new = target_freq;
    
    	cpufreq_freq_transition_begin(policy, &freqs);
    
    	switch (relation) {
    	case CPUFREQ_RELATION_L:
    		target_pstate = DIV_ROUND_UP(freqs.new, cpu->pstate.scaling);
    		break;
    	case CPUFREQ_RELATION_H:
    		target_pstate = freqs.new / cpu->pstate.scaling;
    		break;
    	default:
    		target_pstate = DIV_ROUND_CLOSEST(freqs.new, cpu->pstate.scaling);
    		break;
    	}
    
    	target_pstate = intel_cpufreq_update_pstate(policy, target_pstate, false);
    
    	freqs.new = target_pstate * cpu->pstate.scaling;
    
    	cpufreq_freq_transition_end(policy, &freqs, false);
    
    	return 0;
    }
    
    static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy,
    					      unsigned int target_freq)
    {
    	struct cpudata *cpu = all_cpu_data[policy->cpu];
    	int target_pstate;
    
    	update_turbo_state();
    
    	target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling);
    
    	target_pstate = intel_cpufreq_update_pstate(policy, target_pstate, true);
    
    	return target_pstate * cpu->pstate.scaling;
    }
    
    static void intel_cpufreq_adjust_perf(unsigned int cpunum,
    				      unsigned long min_perf,
    				      unsigned long target_perf,
    				      unsigned long capacity)
    {
    	struct cpudata *cpu = all_cpu_data[cpunum];
    	u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached);
    	int old_pstate = cpu->pstate.current_pstate;
    	int cap_pstate, min_pstate, max_pstate, target_pstate;
    
    	update_turbo_state();
    	cap_pstate = global.turbo_disabled ? HWP_GUARANTEED_PERF(hwp_cap) :
    					     HWP_HIGHEST_PERF(hwp_cap);
    
    	/* Optimization: Avoid unnecessary divisions. */
    
    	target_pstate = cap_pstate;
    	if (target_perf < capacity)
    		target_pstate = DIV_ROUND_UP(cap_pstate * target_perf, capacity);
    
    	min_pstate = cap_pstate;
    	if (min_perf < capacity)
    		min_pstate = DIV_ROUND_UP(cap_pstate * min_perf, capacity);
    
    	if (min_pstate < cpu->pstate.min_pstate)
    		min_pstate = cpu->pstate.min_pstate;
    
    	if (min_pstate < cpu->min_perf_ratio)
    		min_pstate = cpu->min_perf_ratio;
    
    	max_pstate = min(cap_pstate, cpu->max_perf_ratio);
    	if (max_pstate < min_pstate)
    		max_pstate = min_pstate;
    
    	target_pstate = clamp_t(int, target_pstate, min_pstate, max_pstate);
    
    	intel_cpufreq_hwp_update(cpu, min_pstate, max_pstate, target_pstate, true);
    
    	cpu->pstate.current_pstate = target_pstate;
    	intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_FAST_SWITCH, old_pstate);
    }
    
    static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy)
    {
    	struct freq_qos_request *req;
    	struct cpudata *cpu;
    	struct device *dev;
    	int ret, freq;
    
    	dev = get_cpu_device(policy->cpu);
    	if (!dev)
    		return -ENODEV;
    
    	ret = __intel_pstate_cpu_init(policy);
    	if (ret)
    		return ret;
    
    	policy->cpuinfo.transition_latency = INTEL_CPUFREQ_TRANSITION_LATENCY;
    	/* This reflects the intel_pstate_get_cpu_pstates() setting. */
    	policy->cur = policy->cpuinfo.min_freq;
    
    	req = kcalloc(2, sizeof(*req), GFP_KERNEL);
    	if (!req) {
    		ret = -ENOMEM;
    		goto pstate_exit;
    	}
    
    	cpu = all_cpu_data[policy->cpu];
    
    	if (hwp_active) {
    		u64 value;
    
    		policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY_HWP;
    
    		intel_pstate_get_hwp_cap(cpu);
    
    		rdmsrl_on_cpu(cpu->cpu, MSR_HWP_REQUEST, &value);
    		WRITE_ONCE(cpu->hwp_req_cached, value);
    
    		cpu->epp_cached = intel_pstate_get_epp(cpu, value);
    	} else {
    		policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY;
    	}
    
    	freq = DIV_ROUND_UP(cpu->pstate.turbo_freq * global.min_perf_pct, 100);
    
    	ret = freq_qos_add_request(&policy->constraints, req, FREQ_QOS_MIN,
    				   freq);
    	if (ret < 0) {
    		dev_err(dev, "Failed to add min-freq constraint (%d)\n", ret);
    		goto free_req;
    	}
    
    	freq = DIV_ROUND_UP(cpu->pstate.turbo_freq * global.max_perf_pct, 100);
    
    	ret = freq_qos_add_request(&policy->constraints, req + 1, FREQ_QOS_MAX,
    				   freq);
    	if (ret < 0) {
    		dev_err(dev, "Failed to add max-freq constraint (%d)\n", ret);
    		goto remove_min_req;
    	}
    
    	policy->driver_data = req;
    
    	return 0;
    
    remove_min_req:
    	freq_qos_remove_request(req);
    free_req:
    	kfree(req);
    pstate_exit:
    	intel_pstate_exit_perf_limits(policy);
    
    	return ret;
    }
    
    static int intel_cpufreq_cpu_exit(struct cpufreq_policy *policy)
    {
    	struct freq_qos_request *req;
    
    	req = policy->driver_data;
    
    	freq_qos_remove_request(req + 1);
    	freq_qos_remove_request(req);
    	kfree(req);
    
    	return intel_pstate_cpu_exit(policy);
    }
    
    static struct cpufreq_driver intel_cpufreq = {
    	.flags		= CPUFREQ_CONST_LOOPS,
    	.verify		= intel_cpufreq_verify_policy,
    	.target		= intel_cpufreq_target,
    	.fast_switch	= intel_cpufreq_fast_switch,
    	.init		= intel_cpufreq_cpu_init,
    	.exit		= intel_cpufreq_cpu_exit,
    	.offline	= intel_cpufreq_cpu_offline,
    	.online		= intel_pstate_cpu_online,
    	.suspend	= intel_pstate_suspend,
    	.resume		= intel_pstate_resume,
    	.update_limits	= intel_pstate_update_limits,
    	.name		= "intel_cpufreq",
    };
    
    static struct cpufreq_driver *default_driver;
    
    static void intel_pstate_driver_cleanup(void)
    {
    	unsigned int cpu;
    
    	cpus_read_lock();
    	for_each_online_cpu(cpu) {
    		if (all_cpu_data[cpu]) {
    			if (intel_pstate_driver == &intel_pstate)
    				intel_pstate_clear_update_util_hook(cpu);
    
    			kfree(all_cpu_data[cpu]);
    			all_cpu_data[cpu] = NULL;
    		}
    	}
    	cpus_read_unlock();
    
    	intel_pstate_driver = NULL;
    }
    
    static int intel_pstate_register_driver(struct cpufreq_driver *driver)
    {
    	int ret;
    
    	if (driver == &intel_pstate)
    		intel_pstate_sysfs_expose_hwp_dynamic_boost();
    
    	memset(&global, 0, sizeof(global));
    	global.max_perf_pct = 100;
    
    	intel_pstate_driver = driver;
    	ret = cpufreq_register_driver(intel_pstate_driver);
    	if (ret) {
    		intel_pstate_driver_cleanup();
    		return ret;
    	}
    
    	global.min_perf_pct = min_perf_pct_min();
    
    	return 0;
    }
    
    static ssize_t intel_pstate_show_status(char *buf)
    {
    	if (!intel_pstate_driver)
    		return sprintf(buf, "off\n");
    
    	return sprintf(buf, "%s\n", intel_pstate_driver == &intel_pstate ?
    					"active" : "passive");
    }
    
    static int intel_pstate_update_status(const char *buf, size_t size)
    {
    	if (size == 3 && !strncmp(buf, "off", size)) {
    		if (!intel_pstate_driver)
    			return -EINVAL;
    
    		if (hwp_active)
    			return -EBUSY;
    
    		cpufreq_unregister_driver(intel_pstate_driver);
    		intel_pstate_driver_cleanup();
    		return 0;
    	}
    
    	if (size == 6 && !strncmp(buf, "active", size)) {
    		if (intel_pstate_driver) {
    			if (intel_pstate_driver == &intel_pstate)
    				return 0;
    
    			cpufreq_unregister_driver(intel_pstate_driver);
    		}
    
    		return intel_pstate_register_driver(&intel_pstate);
    	}
    
    	if (size == 7 && !strncmp(buf, "passive", size)) {
    		if (intel_pstate_driver) {
    			if (intel_pstate_driver == &intel_cpufreq)
    				return 0;
    
    			cpufreq_unregister_driver(intel_pstate_driver);
    			intel_pstate_sysfs_hide_hwp_dynamic_boost();
    		}
    
    		return intel_pstate_register_driver(&intel_cpufreq);
    	}
    
    	return -EINVAL;
    }
    
    static int no_load __initdata;
    static int no_hwp __initdata;
    static int hwp_only __initdata;
    static unsigned int force_load __initdata;
    
    static int __init intel_pstate_msrs_not_valid(void)
    {
    	if (!pstate_funcs.get_max() ||
    	    !pstate_funcs.get_min() ||
    	    !pstate_funcs.get_turbo())
    		return -ENODEV;
    
    	return 0;
    }
    
    static void __init copy_cpu_funcs(struct pstate_funcs *funcs)
    {
    	pstate_funcs.get_max   = funcs->get_max;
    	pstate_funcs.get_max_physical = funcs->get_max_physical;
    	pstate_funcs.get_min   = funcs->get_min;
    	pstate_funcs.get_turbo = funcs->get_turbo;
    	pstate_funcs.get_scaling = funcs->get_scaling;
    	pstate_funcs.get_val   = funcs->get_val;
    	pstate_funcs.get_vid   = funcs->get_vid;
    	pstate_funcs.get_aperf_mperf_shift = funcs->get_aperf_mperf_shift;
    }
    
    #ifdef CONFIG_ACPI
    
    static bool __init intel_pstate_no_acpi_pss(void)
    {
    	int i;
    
    	for_each_possible_cpu(i) {
    		acpi_status status;
    		union acpi_object *pss;
    		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
    		struct acpi_processor *pr = per_cpu(processors, i);
    
    		if (!pr)
    			continue;
    
    		status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
    		if (ACPI_FAILURE(status))
    			continue;
    
    		pss = buffer.pointer;
    		if (pss && pss->type == ACPI_TYPE_PACKAGE) {
    			kfree(pss);
    			return false;
    		}
    
    		kfree(pss);
    	}
    
    	pr_debug("ACPI _PSS not found\n");
    	return true;
    }
    
    static bool __init intel_pstate_no_acpi_pcch(void)
    {
    	acpi_status status;
    	acpi_handle handle;
    
    	status = acpi_get_handle(NULL, "\\_SB", &handle);
    	if (ACPI_FAILURE(status))
    		goto not_found;
    
    	if (acpi_has_method(handle, "PCCH"))
    		return false;
    
    not_found:
    	pr_debug("ACPI PCCH not found\n");
    	return true;
    }
    
    static bool __init intel_pstate_has_acpi_ppc(void)
    {
    	int i;
    
    	for_each_possible_cpu(i) {
    		struct acpi_processor *pr = per_cpu(processors, i);
    
    		if (!pr)
    			continue;
    		if (acpi_has_method(pr->handle, "_PPC"))
    			return true;
    	}
    	pr_debug("ACPI _PPC not found\n");
    	return false;
    }
    
    enum {
    	PSS,
    	PPC,
    };
    
    /* Hardware vendor-specific info that has its own power management modes */
    static struct acpi_platform_list plat_info[] __initdata = {
    	{"HP    ", "ProLiant", 0, ACPI_SIG_FADT, all_versions, NULL, PSS},
    	{"ORACLE", "X4-2    ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4-2L   ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4-2B   ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X3-2    ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X3-2L   ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X3-2B   ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4470M2 ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4270M3 ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4270M2 ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4170M2 ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4170 M3", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X4275 M3", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "X6-2    ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{"ORACLE", "Sudbury ", 0, ACPI_SIG_FADT, all_versions, NULL, PPC},
    	{ } /* End */
    };
    
    #define BITMASK_OOB	(BIT(8) | BIT(18))
    
    static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
    {
    	const struct x86_cpu_id *id;
    	u64 misc_pwr;
    	int idx;
    
    	id = x86_match_cpu(intel_pstate_cpu_oob_ids);
    	if (id) {
    		rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
    		if (misc_pwr & BITMASK_OOB) {
    			pr_debug("Bit 8 or 18 in the MISC_PWR_MGMT MSR set\n");
    			pr_debug("P states are controlled in Out of Band mode by the firmware/hardware\n");
    			return true;
    		}
    	}
    
    	idx = acpi_match_platform_list(plat_info);
    	if (idx < 0)
    		return false;
    
    	switch (plat_info[idx].data) {
    	case PSS:
    		if (!intel_pstate_no_acpi_pss())
    			return false;
    
    		return intel_pstate_no_acpi_pcch();
    	case PPC:
    		return intel_pstate_has_acpi_ppc() && !force_load;
    	}
    
    	return false;
    }
    
    static void intel_pstate_request_control_from_smm(void)
    {
    	/*
    	 * It may be unsafe to request P-states control from SMM if _PPC support
    	 * has not been enabled.
    	 */
    	if (acpi_ppc)
    		acpi_processor_pstate_control();
    }
    #else /* CONFIG_ACPI not enabled */
    static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
    static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
    static inline void intel_pstate_request_control_from_smm(void) {}
    #endif /* CONFIG_ACPI */
    
    #define INTEL_PSTATE_HWP_BROADWELL	0x01
    
    #define X86_MATCH_HWP(model, hwp_mode)					\
    	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, INTEL_FAM6_##model, \
    					   X86_FEATURE_HWP, hwp_mode)
    
    static const struct x86_cpu_id hwp_support_ids[] __initconst = {
    	X86_MATCH_HWP(BROADWELL_X,	INTEL_PSTATE_HWP_BROADWELL),
    	X86_MATCH_HWP(BROADWELL_D,	INTEL_PSTATE_HWP_BROADWELL),
    	X86_MATCH_HWP(ANY,		0),
    	{}
    };
    
    static bool intel_pstate_hwp_is_enabled(void)
    {
    	u64 value;
    
    	rdmsrl(MSR_PM_ENABLE, value);
    	return !!(value & 0x1);
    }
    
    static int __init intel_pstate_init(void)
    {
    	const struct x86_cpu_id *id;
    	int rc;
    
    	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
    		return -ENODEV;
    
    	id = x86_match_cpu(hwp_support_ids);
    	if (id) {
    		bool hwp_forced = intel_pstate_hwp_is_enabled();
    
    		if (hwp_forced)
    			pr_info("HWP enabled by BIOS\n");
    		else if (no_load)
    			return -ENODEV;
    
    		copy_cpu_funcs(&core_funcs);
    		/*
    		 * Avoid enabling HWP for processors without EPP support,
    		 * because that means incomplete HWP implementation which is a
    		 * corner case and supporting it is generally problematic.
    		 *
    		 * If HWP is enabled already, though, there is no choice but to
    		 * deal with it.
    		 */
    		if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) {
    			hwp_active++;
    			hwp_mode_bdw = id->driver_data;
    			intel_pstate.attr = hwp_cpufreq_attrs;
    			intel_cpufreq.attr = hwp_cpufreq_attrs;
    			intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS;
    			intel_cpufreq.adjust_perf = intel_cpufreq_adjust_perf;
    			if (!default_driver)
    				default_driver = &intel_pstate;
    
    			if (boot_cpu_has(X86_FEATURE_HYBRID_CPU))
    				intel_pstate_cppc_set_cpu_scaling();
    
    			goto hwp_cpu_matched;
    		}
    		pr_info("HWP not enabled\n");
    	} else {
    		if (no_load)
    			return -ENODEV;
    
    		id = x86_match_cpu(intel_pstate_cpu_ids);
    		if (!id) {
    			pr_info("CPU model not supported\n");
    			return -ENODEV;
    		}
    
    		copy_cpu_funcs((struct pstate_funcs *)id->driver_data);
    	}
    
    	if (intel_pstate_msrs_not_valid()) {
    		pr_info("Invalid MSRs\n");
    		return -ENODEV;
    	}
    	/* Without HWP start in the passive mode. */
    	if (!default_driver)
    		default_driver = &intel_cpufreq;
    
    hwp_cpu_matched:
    	/*
    	 * The Intel pstate driver will be ignored if the platform
    	 * firmware has its own power management modes.
    	 */
    	if (intel_pstate_platform_pwr_mgmt_exists()) {
    		pr_info("P-states controlled by the platform\n");
    		return -ENODEV;
    	}
    
    	if (!hwp_active && hwp_only)
    		return -ENOTSUPP;
    
    	pr_info("Intel P-state driver initializing\n");
    
    	all_cpu_data = vzalloc(array_size(sizeof(void *), num_possible_cpus()));
    	if (!all_cpu_data)
    		return -ENOMEM;
    
    	intel_pstate_request_control_from_smm();
    
    	intel_pstate_sysfs_expose_params();
    
    	mutex_lock(&intel_pstate_driver_lock);
    	rc = intel_pstate_register_driver(default_driver);
    	mutex_unlock(&intel_pstate_driver_lock);
    	if (rc) {
    		intel_pstate_sysfs_remove();
    		return rc;
    	}
    
    	if (hwp_active) {
    		const struct x86_cpu_id *id;
    
    		id = x86_match_cpu(intel_pstate_cpu_ee_disable_ids);
    		if (id) {
    			set_power_ctl_ee_state(false);
    			pr_info("Disabling energy efficiency optimization\n");
    		}
    
    		pr_info("HWP enabled\n");
    	} else if (boot_cpu_has(X86_FEATURE_HYBRID_CPU)) {
    		pr_warn("Problematic setup: Hybrid processor with disabled HWP\n");
    	}
    
    	return 0;
    }
    device_initcall(intel_pstate_init);
    
    static int __init intel_pstate_setup(char *str)
    {
    	if (!str)
    		return -EINVAL;
    
    	if (!strcmp(str, "disable"))
    		no_load = 1;
    	else if (!strcmp(str, "active"))
    		default_driver = &intel_pstate;
    	else if (!strcmp(str, "passive"))
    		default_driver = &intel_cpufreq;
    
    	if (!strcmp(str, "no_hwp"))
    		no_hwp = 1;
    
    	if (!strcmp(str, "force"))
    		force_load = 1;
    	if (!strcmp(str, "hwp_only"))
    		hwp_only = 1;
    	if (!strcmp(str, "per_cpu_perf_limits"))
    		per_cpu_limits = true;
    
    #ifdef CONFIG_ACPI
    	if (!strcmp(str, "support_acpi_ppc"))
    		acpi_ppc = true;
    #endif
    
    	return 0;
    }
    early_param("intel_pstate", intel_pstate_setup);
    
    MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
    MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
    MODULE_LICENSE("GPL");