text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * acpi-cpufreq.c - ACPI Processor P-States Driver
   *
   *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
   *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/smp.h>
  #include <linux/sched.h>
  #include <linux/cpufreq.h>
  #include <linux/compiler.h>
  #include <linux/dmi.h>
  #include <linux/slab.h>
  
  #include <linux/acpi.h>
  #include <linux/io.h>
  #include <linux/delay.h>
  #include <linux/uaccess.h>
  
  #include <acpi/processor.h>
  #include <acpi/cppc_acpi.h>
  
  #include <asm/msr.h>
  #include <asm/processor.h>
  #include <asm/cpufeature.h>
  #include <asm/cpu_device_id.h>
  
  MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  MODULE_LICENSE("GPL");
  
  enum {
  	UNDEFINED_CAPABLE = 0,
  	SYSTEM_INTEL_MSR_CAPABLE,
  	SYSTEM_AMD_MSR_CAPABLE,
  	SYSTEM_IO_CAPABLE,
  };
  
  #define INTEL_MSR_RANGE		(0xffff)
  #define AMD_MSR_RANGE		(0x7)
  #define HYGON_MSR_RANGE		(0x7)
  
  #define MSR_K7_HWCR_CPB_DIS	(1ULL << 25)
  
  struct acpi_cpufreq_data {
  	unsigned int resume;
  	unsigned int cpu_feature;
  	unsigned int acpi_perf_cpu;
  	cpumask_var_t freqdomain_cpus;
  	void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
  	u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
  };
  
  /* acpi_perf_data is a pointer to percpu data. */
  static struct acpi_processor_performance __percpu *acpi_perf_data;
  
  static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
  {
  	return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
  }
  
  static struct cpufreq_driver acpi_cpufreq_driver;
  
  static unsigned int acpi_pstate_strict;
  
  static bool boost_state(unsigned int cpu)
  {
  	u32 lo, hi;
  	u64 msr;
  
  	switch (boot_cpu_data.x86_vendor) {
  	case X86_VENDOR_INTEL:
  		rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
  		msr = lo | ((u64)hi << 32);
  		return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
  	case X86_VENDOR_HYGON:
  	case X86_VENDOR_AMD:
  		rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
  		msr = lo | ((u64)hi << 32);
  		return !(msr & MSR_K7_HWCR_CPB_DIS);
  	}
  	return false;
  }
  
  static int boost_set_msr(bool enable)
  {
  	u32 msr_addr;
  	u64 msr_mask, val;
  
  	switch (boot_cpu_data.x86_vendor) {
  	case X86_VENDOR_INTEL:
  		msr_addr = MSR_IA32_MISC_ENABLE;
  		msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
  		break;
  	case X86_VENDOR_HYGON:
  	case X86_VENDOR_AMD:
  		msr_addr = MSR_K7_HWCR;
  		msr_mask = MSR_K7_HWCR_CPB_DIS;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	rdmsrl(msr_addr, val);
  
  	if (enable)
  		val &= ~msr_mask;
  	else
  		val |= msr_mask;
  
  	wrmsrl(msr_addr, val);
  	return 0;
  }
  
  static void boost_set_msr_each(void *p_en)
  {
  	bool enable = (bool) p_en;
  
  	boost_set_msr(enable);
  }
  
  static int set_boost(struct cpufreq_policy *policy, int val)
  {
  	on_each_cpu_mask(policy->cpus, boost_set_msr_each,
  			 (void *)(long)val, 1);
  	pr_debug("CPU %*pbl: Core Boosting %sabled.\n",
  		 cpumask_pr_args(policy->cpus), val ? "en" : "dis");
  
  	return 0;
  }
  
  static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  
  	if (unlikely(!data))
  		return -ENODEV;
  
  	return cpufreq_show_cpus(data->freqdomain_cpus, buf);
  }
  
  cpufreq_freq_attr_ro(freqdomain_cpus);
  
  #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
  static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
  			 size_t count)
  {
  	int ret;
  	unsigned int val = 0;
  
  	if (!acpi_cpufreq_driver.set_boost)
  		return -EINVAL;
  
  	ret = kstrtouint(buf, 10, &val);
  	if (ret || val > 1)
  		return -EINVAL;
  
  	get_online_cpus();
  	set_boost(policy, val);
  	put_online_cpus();
  
  	return count;
  }
  
  static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
  {
  	return sprintf(buf, "%u\n", acpi_cpufreq_driver.boost_enabled);
  }
  
  cpufreq_freq_attr_rw(cpb);
  #endif
  
  static int check_est_cpu(unsigned int cpuid)
  {
  	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  
  	return cpu_has(cpu, X86_FEATURE_EST);
  }
  
  static int check_amd_hwpstate_cpu(unsigned int cpuid)
  {
  	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  
  	return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
  }
  
  static unsigned extract_io(struct cpufreq_policy *policy, u32 value)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  	struct acpi_processor_performance *perf;
  	int i;
  
  	perf = to_perf_data(data);
  
  	for (i = 0; i < perf->state_count; i++) {
  		if (value == perf->states[i].status)
  			return policy->freq_table[i].frequency;
  	}
  	return 0;
  }
  
  static unsigned extract_msr(struct cpufreq_policy *policy, u32 msr)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  	struct cpufreq_frequency_table *pos;
  	struct acpi_processor_performance *perf;
  
  	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
  		msr &= AMD_MSR_RANGE;
  	else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
  		msr &= HYGON_MSR_RANGE;
  	else
  		msr &= INTEL_MSR_RANGE;
  
  	perf = to_perf_data(data);
  
  	cpufreq_for_each_entry(pos, policy->freq_table)
  		if (msr == perf->states[pos->driver_data].status)
  			return pos->frequency;
  	return policy->freq_table[0].frequency;
  }
  
  static unsigned extract_freq(struct cpufreq_policy *policy, u32 val)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  
  	switch (data->cpu_feature) {
  	case SYSTEM_INTEL_MSR_CAPABLE:
  	case SYSTEM_AMD_MSR_CAPABLE:
  		return extract_msr(policy, val);
  	case SYSTEM_IO_CAPABLE:
  		return extract_io(policy, val);
  	default:
  		return 0;
  	}
  }
  
  static u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
  {
  	u32 val, dummy __always_unused;
  
  	rdmsr(MSR_IA32_PERF_CTL, val, dummy);
  	return val;
  }
  
  static void cpu_freq_write_intel(struct acpi_pct_register *not_used, u32 val)
  {
  	u32 lo, hi;
  
  	rdmsr(MSR_IA32_PERF_CTL, lo, hi);
  	lo = (lo & ~INTEL_MSR_RANGE) | (val & INTEL_MSR_RANGE);
  	wrmsr(MSR_IA32_PERF_CTL, lo, hi);
  }
  
  static u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
  {
  	u32 val, dummy __always_unused;
  
  	rdmsr(MSR_AMD_PERF_CTL, val, dummy);
  	return val;
  }
  
  static void cpu_freq_write_amd(struct acpi_pct_register *not_used, u32 val)
  {
  	wrmsr(MSR_AMD_PERF_CTL, val, 0);
  }
  
  static u32 cpu_freq_read_io(struct acpi_pct_register *reg)
  {
  	u32 val;
  
  	acpi_os_read_port(reg->address, &val, reg->bit_width);
  	return val;
  }
  
  static void cpu_freq_write_io(struct acpi_pct_register *reg, u32 val)
  {
  	acpi_os_write_port(reg->address, val, reg->bit_width);
  }
  
  struct drv_cmd {
  	struct acpi_pct_register *reg;
  	u32 val;
  	union {
  		void (*write)(struct acpi_pct_register *reg, u32 val);
  		u32 (*read)(struct acpi_pct_register *reg);
  	} func;
  };
  
  /* Called via smp_call_function_single(), on the target CPU */
  static void do_drv_read(void *_cmd)
  {
  	struct drv_cmd *cmd = _cmd;
  
  	cmd->val = cmd->func.read(cmd->reg);
  }
  
  static u32 drv_read(struct acpi_cpufreq_data *data, const struct cpumask *mask)
  {
  	struct acpi_processor_performance *perf = to_perf_data(data);
  	struct drv_cmd cmd = {
  		.reg = &perf->control_register,
  		.func.read = data->cpu_freq_read,
  	};
  	int err;
  
  	err = smp_call_function_any(mask, do_drv_read, &cmd, 1);
  	WARN_ON_ONCE(err);	/* smp_call_function_any() was buggy? */
  	return cmd.val;
  }
  
  /* Called via smp_call_function_many(), on the target CPUs */
  static void do_drv_write(void *_cmd)
  {
  	struct drv_cmd *cmd = _cmd;
  
  	cmd->func.write(cmd->reg, cmd->val);
  }
  
  static void drv_write(struct acpi_cpufreq_data *data,
  		      const struct cpumask *mask, u32 val)
  {
  	struct acpi_processor_performance *perf = to_perf_data(data);
  	struct drv_cmd cmd = {
  		.reg = &perf->control_register,
  		.val = val,
  		.func.write = data->cpu_freq_write,
  	};
  	int this_cpu;
  
  	this_cpu = get_cpu();
  	if (cpumask_test_cpu(this_cpu, mask))
  		do_drv_write(&cmd);
  
  	smp_call_function_many(mask, do_drv_write, &cmd, 1);
  	put_cpu();
  }
  
  static u32 get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
  {
  	u32 val;
  
  	if (unlikely(cpumask_empty(mask)))
  		return 0;
  
  	val = drv_read(data, mask);
  
  	pr_debug("%s = %u\n", __func__, val);
  
  	return val;
  }
  
  static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
  {
  	struct acpi_cpufreq_data *data;
  	struct cpufreq_policy *policy;
  	unsigned int freq;
  	unsigned int cached_freq;
  
  	pr_debug("%s (%d)\n", __func__, cpu);
  
  	policy = cpufreq_cpu_get_raw(cpu);
  	if (unlikely(!policy))
  		return 0;
  
  	data = policy->driver_data;
  	if (unlikely(!data || !policy->freq_table))
  		return 0;
  
  	cached_freq = policy->freq_table[to_perf_data(data)->state].frequency;
  	freq = extract_freq(policy, get_cur_val(cpumask_of(cpu), data));
  	if (freq != cached_freq) {
  		/*
  		 * The dreaded BIOS frequency change behind our back.
  		 * Force set the frequency on next target call.
  		 */
  		data->resume = 1;
  	}
  
  	pr_debug("cur freq = %u\n", freq);
  
  	return freq;
  }
  
  static unsigned int check_freqs(struct cpufreq_policy *policy,
  				const struct cpumask *mask, unsigned int freq)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  	unsigned int cur_freq;
  	unsigned int i;
  
  	for (i = 0; i < 100; i++) {
  		cur_freq = extract_freq(policy, get_cur_val(mask, data));
  		if (cur_freq == freq)
  			return 1;
  		udelay(10);
  	}
  	return 0;
  }
  
  static int acpi_cpufreq_target(struct cpufreq_policy *policy,
  			       unsigned int index)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  	struct acpi_processor_performance *perf;
  	const struct cpumask *mask;
  	unsigned int next_perf_state = 0; /* Index into perf table */
  	int result = 0;
  
  	if (unlikely(!data)) {
  		return -ENODEV;
  	}
  
  	perf = to_perf_data(data);
  	next_perf_state = policy->freq_table[index].driver_data;
  	if (perf->state == next_perf_state) {
  		if (unlikely(data->resume)) {
  			pr_debug("Called after resume, resetting to P%d\n",
  				next_perf_state);
  			data->resume = 0;
  		} else {
  			pr_debug("Already at target state (P%d)\n",
  				next_perf_state);
  			return 0;
  		}
  	}
  
  	/*
  	 * The core won't allow CPUs to go away until the governor has been
  	 * stopped, so we can rely on the stability of policy->cpus.
  	 */
  	mask = policy->shared_type == CPUFREQ_SHARED_TYPE_ANY ?
  		cpumask_of(policy->cpu) : policy->cpus;
  
  	drv_write(data, mask, perf->states[next_perf_state].control);
  
  	if (acpi_pstate_strict) {
  		if (!check_freqs(policy, mask,
  				 policy->freq_table[index].frequency)) {
  			pr_debug("%s (%d)\n", __func__, policy->cpu);
  			result = -EAGAIN;
  		}
  	}
  
  	if (!result)
  		perf->state = next_perf_state;
  
  	return result;
  }
  
  static unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
  					     unsigned int target_freq)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  	struct acpi_processor_performance *perf;
  	struct cpufreq_frequency_table *entry;
  	unsigned int next_perf_state, next_freq, index;
  
  	/*
  	 * Find the closest frequency above target_freq.
  	 */
  	if (policy->cached_target_freq == target_freq)
  		index = policy->cached_resolved_idx;
  	else
  		index = cpufreq_table_find_index_dl(policy, target_freq);
  
  	entry = &policy->freq_table[index];
  	next_freq = entry->frequency;
  	next_perf_state = entry->driver_data;
  
  	perf = to_perf_data(data);
  	if (perf->state == next_perf_state) {
  		if (unlikely(data->resume))
  			data->resume = 0;
  		else
  			return next_freq;
  	}
  
  	data->cpu_freq_write(&perf->control_register,
  			     perf->states[next_perf_state].control);
  	perf->state = next_perf_state;
  	return next_freq;
  }
  
  static unsigned long
  acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
  {
  	struct acpi_processor_performance *perf;
  
  	perf = to_perf_data(data);
  	if (cpu_khz) {
  		/* search the closest match to cpu_khz */
  		unsigned int i;
  		unsigned long freq;
  		unsigned long freqn = perf->states[0].core_frequency * 1000;
  
  		for (i = 0; i < (perf->state_count-1); i++) {
  			freq = freqn;
  			freqn = perf->states[i+1].core_frequency * 1000;
  			if ((2 * cpu_khz) > (freqn + freq)) {
  				perf->state = i;
  				return freq;
  			}
  		}
  		perf->state = perf->state_count-1;
  		return freqn;
  	} else {
  		/* assume CPU is at P0... */
  		perf->state = 0;
  		return perf->states[0].core_frequency * 1000;
  	}
  }
  
  static void free_acpi_perf_data(void)
  {
  	unsigned int i;
  
  	/* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
  	for_each_possible_cpu(i)
  		free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
  				 ->shared_cpu_map);
  	free_percpu(acpi_perf_data);
  }
  
  static int cpufreq_boost_online(unsigned int cpu)
  {
  	/*
  	 * On the CPU_UP path we simply keep the boost-disable flag
  	 * in sync with the current global state.
  	 */
  	return boost_set_msr(acpi_cpufreq_driver.boost_enabled);
  }
  
  static int cpufreq_boost_down_prep(unsigned int cpu)
  {
  	/*
  	 * Clear the boost-disable bit on the CPU_DOWN path so that
  	 * this cpu cannot block the remaining ones from boosting.
  	 */
  	return boost_set_msr(1);
  }
  
  /*
   * acpi_cpufreq_early_init - initialize ACPI P-States library
   *
   * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
   * in order to determine correct frequency and voltage pairings. We can
   * do _PDC and _PSD and find out the processor dependency for the
   * actual init that will happen later...
   */
  static int __init acpi_cpufreq_early_init(void)
  {
  	unsigned int i;
  	pr_debug("%s\n", __func__);
  
  	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
  	if (!acpi_perf_data) {
  		pr_debug("Memory allocation error for acpi_perf_data.\n");
  		return -ENOMEM;
  	}
  	for_each_possible_cpu(i) {
  		if (!zalloc_cpumask_var_node(
  			&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
  			GFP_KERNEL, cpu_to_node(i))) {
  
  			/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
  			free_acpi_perf_data();
  			return -ENOMEM;
  		}
  	}
  
  	/* Do initialization in ACPI core */
  	acpi_processor_preregister_performance(acpi_perf_data);
  	return 0;
  }
  
  #ifdef CONFIG_SMP
  /*
   * Some BIOSes do SW_ANY coordination internally, either set it up in hw
   * or do it in BIOS firmware and won't inform about it to OS. If not
   * detected, this has a side effect of making CPU run at a different speed
   * than OS intended it to run at. Detect it and handle it cleanly.
   */
  static int bios_with_sw_any_bug;
  
  static int sw_any_bug_found(const struct dmi_system_id *d)
  {
  	bios_with_sw_any_bug = 1;
  	return 0;
  }
  
  static const struct dmi_system_id sw_any_bug_dmi_table[] = {
  	{
  		.callback = sw_any_bug_found,
  		.ident = "Supermicro Server X6DLP",
  		.matches = {
  			DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
  			DMI_MATCH(DMI_BIOS_VERSION, "080010"),
  			DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
  		},
  	},
  	{ }
  };
  
  static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
  {
  	/* Intel Xeon Processor 7100 Series Specification Update
  	 * https://www.intel.com/Assets/PDF/specupdate/314554.pdf
  	 * AL30: A Machine Check Exception (MCE) Occurring during an
  	 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
  	 * Both Processor Cores to Lock Up. */
  	if (c->x86_vendor == X86_VENDOR_INTEL) {
  		if ((c->x86 == 15) &&
  		    (c->x86_model == 6) &&
  		    (c->x86_stepping == 8)) {
  			pr_info("Intel(R) Xeon(R) 7100 Errata AL30, processors may lock up on frequency changes: disabling acpi-cpufreq\n");
  			return -ENODEV;
  		    }
  		}
  	return 0;
  }
  #endif
  
  #ifdef CONFIG_ACPI_CPPC_LIB
  static u64 get_max_boost_ratio(unsigned int cpu)
  {
  	struct cppc_perf_caps perf_caps;
  	u64 highest_perf, nominal_perf;
  	int ret;
  
  	if (acpi_pstate_strict)
  		return 0;
  
  	ret = cppc_get_perf_caps(cpu, &perf_caps);
  	if (ret) {
  		pr_debug("CPU%d: Unable to get performance capabilities (%d)\n",
  			 cpu, ret);
  		return 0;
  	}
  
  	highest_perf = perf_caps.highest_perf;
  	nominal_perf = perf_caps.nominal_perf;
  
  	if (!highest_perf || !nominal_perf) {
  		pr_debug("CPU%d: highest or nominal performance missing\n", cpu);
  		return 0;
  	}
  
  	if (highest_perf < nominal_perf) {
  		pr_debug("CPU%d: nominal performance above highest\n", cpu);
  		return 0;
  	}
  
  	return div_u64(highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
  }
  #else
  static inline u64 get_max_boost_ratio(unsigned int cpu) { return 0; }
  #endif
  
  static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
  {
  	struct cpufreq_frequency_table *freq_table;
  	struct acpi_processor_performance *perf;
  	struct acpi_cpufreq_data *data;
  	unsigned int cpu = policy->cpu;
  	struct cpuinfo_x86 *c = &cpu_data(cpu);
  	unsigned int valid_states = 0;
  	unsigned int result = 0;
  	u64 max_boost_ratio;
  	unsigned int i;
  #ifdef CONFIG_SMP
  	static int blacklisted;
  #endif
  
  	pr_debug("%s\n", __func__);
  
  #ifdef CONFIG_SMP
  	if (blacklisted)
  		return blacklisted;
  	blacklisted = acpi_cpufreq_blacklist(c);
  	if (blacklisted)
  		return blacklisted;
  #endif
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
  		result = -ENOMEM;
  		goto err_free;
  	}
  
  	perf = per_cpu_ptr(acpi_perf_data, cpu);
  	data->acpi_perf_cpu = cpu;
  	policy->driver_data = data;
  
  	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
  		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
  
  	result = acpi_processor_register_performance(perf, cpu);
  	if (result)
  		goto err_free_mask;
  
  	policy->shared_type = perf->shared_type;
  
  	/*
  	 * Will let policy->cpus know about dependency only when software
  	 * coordination is required.
  	 */
  	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
  	    policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
  		cpumask_copy(policy->cpus, perf->shared_cpu_map);
  	}
  	cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
  
  #ifdef CONFIG_SMP
  	dmi_check_system(sw_any_bug_dmi_table);
  	if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
  		policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
  		cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
  	}
  
  	if (check_amd_hwpstate_cpu(cpu) && boot_cpu_data.x86 < 0x19 &&
  	    !acpi_pstate_strict) {
  		cpumask_clear(policy->cpus);
  		cpumask_set_cpu(cpu, policy->cpus);
  		cpumask_copy(data->freqdomain_cpus,
  			     topology_sibling_cpumask(cpu));
  		policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
  		pr_info_once("overriding BIOS provided _PSD data\n");
  	}
  #endif
  
  	/* capability check */
  	if (perf->state_count <= 1) {
  		pr_debug("No P-States\n");
  		result = -ENODEV;
  		goto err_unreg;
  	}
  
  	if (perf->control_register.space_id != perf->status_register.space_id) {
  		result = -ENODEV;
  		goto err_unreg;
  	}
  
  	switch (perf->control_register.space_id) {
  	case ACPI_ADR_SPACE_SYSTEM_IO:
  		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
  		    boot_cpu_data.x86 == 0xf) {
  			pr_debug("AMD K8 systems must use native drivers.\n");
  			result = -ENODEV;
  			goto err_unreg;
  		}
  		pr_debug("SYSTEM IO addr space\n");
  		data->cpu_feature = SYSTEM_IO_CAPABLE;
  		data->cpu_freq_read = cpu_freq_read_io;
  		data->cpu_freq_write = cpu_freq_write_io;
  		break;
  	case ACPI_ADR_SPACE_FIXED_HARDWARE:
  		pr_debug("HARDWARE addr space\n");
  		if (check_est_cpu(cpu)) {
  			data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
  			data->cpu_freq_read = cpu_freq_read_intel;
  			data->cpu_freq_write = cpu_freq_write_intel;
  			break;
  		}
  		if (check_amd_hwpstate_cpu(cpu)) {
  			data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
  			data->cpu_freq_read = cpu_freq_read_amd;
  			data->cpu_freq_write = cpu_freq_write_amd;
  			break;
  		}
  		result = -ENODEV;
  		goto err_unreg;
  	default:
  		pr_debug("Unknown addr space %d\n",
  			(u32) (perf->control_register.space_id));
  		result = -ENODEV;
  		goto err_unreg;
  	}
  
  	freq_table = kcalloc(perf->state_count + 1, sizeof(*freq_table),
  			     GFP_KERNEL);
  	if (!freq_table) {
  		result = -ENOMEM;
  		goto err_unreg;
  	}
  
  	/* detect transition latency */
  	policy->cpuinfo.transition_latency = 0;
  	for (i = 0; i < perf->state_count; i++) {
  		if ((perf->states[i].transition_latency * 1000) >
  		    policy->cpuinfo.transition_latency)
  			policy->cpuinfo.transition_latency =
  			    perf->states[i].transition_latency * 1000;
  	}
  
  	/* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
  	if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
  	    policy->cpuinfo.transition_latency > 20 * 1000) {
  		policy->cpuinfo.transition_latency = 20 * 1000;
  		pr_info_once("P-state transition latency capped at 20 uS\n");
  	}
  
  	/* table init */
  	for (i = 0; i < perf->state_count; i++) {
  		if (i > 0 && perf->states[i].core_frequency >=
  		    freq_table[valid_states-1].frequency / 1000)
  			continue;
  
  		freq_table[valid_states].driver_data = i;
  		freq_table[valid_states].frequency =
  		    perf->states[i].core_frequency * 1000;
  		valid_states++;
  	}
  	freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
  
  	max_boost_ratio = get_max_boost_ratio(cpu);
  	if (max_boost_ratio) {
  		unsigned int freq = freq_table[0].frequency;
  
  		/*
  		 * Because the loop above sorts the freq_table entries in the
  		 * descending order, freq is the maximum frequency in the table.
  		 * Assume that it corresponds to the CPPC nominal frequency and
  		 * use it to set cpuinfo.max_freq.
  		 */
  		policy->cpuinfo.max_freq = freq * max_boost_ratio >> SCHED_CAPACITY_SHIFT;
  	} else {
  		/*
  		 * If the maximum "boost" frequency is unknown, ask the arch
  		 * scale-invariance code to use the "nominal" performance for
  		 * CPU utilization scaling so as to prevent the schedutil
  		 * governor from selecting inadequate CPU frequencies.
  		 */
  		arch_set_max_freq_ratio(true);
  	}
  
  	policy->freq_table = freq_table;
  	perf->state = 0;
  
  	switch (perf->control_register.space_id) {
  	case ACPI_ADR_SPACE_SYSTEM_IO:
  		/*
  		 * The core will not set policy->cur, because
  		 * cpufreq_driver->get is NULL, so we need to set it here.
  		 * However, we have to guess it, because the current speed is
  		 * unknown and not detectable via IO ports.
  		 */
  		policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
  		break;
  	case ACPI_ADR_SPACE_FIXED_HARDWARE:
  		acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
  		break;
  	default:
  		break;
  	}
  
  	/* notify BIOS that we exist */
  	acpi_processor_notify_smm(THIS_MODULE);
  
  	pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
  	for (i = 0; i < perf->state_count; i++)
  		pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
  			(i == perf->state ? '*' : ' '), i,
  			(u32) perf->states[i].core_frequency,
  			(u32) perf->states[i].power,
  			(u32) perf->states[i].transition_latency);
  
  	/*
  	 * the first call to ->target() should result in us actually
  	 * writing something to the appropriate registers.
  	 */
  	data->resume = 1;
  
  	policy->fast_switch_possible = !acpi_pstate_strict &&
  		!(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
  
  	return result;
  
  err_unreg:
  	acpi_processor_unregister_performance(cpu);
  err_free_mask:
  	free_cpumask_var(data->freqdomain_cpus);
  err_free:
  	kfree(data);
  	policy->driver_data = NULL;
  
  	return result;
  }
  
  static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  
  	pr_debug("%s\n", __func__);
  
  	policy->fast_switch_possible = false;
  	policy->driver_data = NULL;
  	acpi_processor_unregister_performance(data->acpi_perf_cpu);
  	free_cpumask_var(data->freqdomain_cpus);
  	kfree(policy->freq_table);
  	kfree(data);
  
  	return 0;
  }
  
  static void acpi_cpufreq_cpu_ready(struct cpufreq_policy *policy)
  {
  	struct acpi_processor_performance *perf = per_cpu_ptr(acpi_perf_data,
  							      policy->cpu);
  	unsigned int freq = policy->freq_table[0].frequency;
  
  	if (perf->states[0].core_frequency * 1000 != freq)
  		pr_warn(FW_WARN "P-state 0 is not max freq\n");
  }
  
  static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
  {
  	struct acpi_cpufreq_data *data = policy->driver_data;
  
  	pr_debug("%s\n", __func__);
  
  	data->resume = 1;
  
  	return 0;
  }
  
  static struct freq_attr *acpi_cpufreq_attr[] = {
  	&cpufreq_freq_attr_scaling_available_freqs,
  	&freqdomain_cpus,
  #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
  	&cpb,
  #endif
  	NULL,
  };
  
  static struct cpufreq_driver acpi_cpufreq_driver = {
  	.verify		= cpufreq_generic_frequency_table_verify,
  	.target_index	= acpi_cpufreq_target,
  	.fast_switch	= acpi_cpufreq_fast_switch,
  	.bios_limit	= acpi_processor_get_bios_limit,
  	.init		= acpi_cpufreq_cpu_init,
  	.exit		= acpi_cpufreq_cpu_exit,
  	.ready		= acpi_cpufreq_cpu_ready,
  	.resume		= acpi_cpufreq_resume,
  	.name		= "acpi-cpufreq",
  	.attr		= acpi_cpufreq_attr,
  };
  
  static enum cpuhp_state acpi_cpufreq_online;
  
  static void __init acpi_cpufreq_boost_init(void)
  {
  	int ret;
  
  	if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) {
  		pr_debug("Boost capabilities not present in the processor\n");
  		return;
  	}
  
  	acpi_cpufreq_driver.set_boost = set_boost;
  	acpi_cpufreq_driver.boost_enabled = boost_state(0);
  
  	/*
  	 * This calls the online callback on all online cpu and forces all
  	 * MSRs to the same value.
  	 */
  	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpufreq/acpi:online",
  				cpufreq_boost_online, cpufreq_boost_down_prep);
  	if (ret < 0) {
  		pr_err("acpi_cpufreq: failed to register hotplug callbacks\n");
  		return;
  	}
  	acpi_cpufreq_online = ret;
  }
  
  static void acpi_cpufreq_boost_exit(void)
  {
  	if (acpi_cpufreq_online > 0)
  		cpuhp_remove_state_nocalls(acpi_cpufreq_online);
  }
  
  static int __init acpi_cpufreq_init(void)
  {
  	int ret;
  
  	if (acpi_disabled)
  		return -ENODEV;
  
  	/* don't keep reloading if cpufreq_driver exists */
  	if (cpufreq_get_current_driver())
  		return -EEXIST;
  
  	pr_debug("%s\n", __func__);
  
  	ret = acpi_cpufreq_early_init();
  	if (ret)
  		return ret;
  
  #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
  	/* this is a sysfs file with a strange name and an even stranger
  	 * semantic - per CPU instantiation, but system global effect.
  	 * Lets enable it only on AMD CPUs for compatibility reasons and
  	 * only if configured. This is considered legacy code, which
  	 * will probably be removed at some point in the future.
  	 */
  	if (!check_amd_hwpstate_cpu(0)) {
  		struct freq_attr **attr;
  
  		pr_debug("CPB unsupported, do not expose it\n");
  
  		for (attr = acpi_cpufreq_attr; *attr; attr++)
  			if (*attr == &cpb) {
  				*attr = NULL;
  				break;
  			}
  	}
  #endif
  	acpi_cpufreq_boost_init();
  
  	ret = cpufreq_register_driver(&acpi_cpufreq_driver);
  	if (ret) {
  		free_acpi_perf_data();
  		acpi_cpufreq_boost_exit();
  	}
  	return ret;
  }
  
  static void __exit acpi_cpufreq_exit(void)
  {
  	pr_debug("%s\n", __func__);
  
  	acpi_cpufreq_boost_exit();
  
  	cpufreq_unregister_driver(&acpi_cpufreq_driver);
  
  	free_acpi_perf_data();
  }
  
  module_param(acpi_pstate_strict, uint, 0644);
  MODULE_PARM_DESC(acpi_pstate_strict,
  	"value 0 or non-zero. non-zero -> strict ACPI checks are "
  	"performed during frequency changes.");
  
  late_initcall(acpi_cpufreq_init);
  module_exit(acpi_cpufreq_exit);
  
  static const struct x86_cpu_id __maybe_unused acpi_cpufreq_ids[] = {
  	X86_MATCH_FEATURE(X86_FEATURE_ACPI, NULL),
  	X86_MATCH_FEATURE(X86_FEATURE_HW_PSTATE, NULL),
  	{}
  };
  MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
  
  static const struct acpi_device_id __maybe_unused processor_device_ids[] = {
  	{ACPI_PROCESSOR_OBJECT_HID, },
  	{ACPI_PROCESSOR_DEVICE_HID, },
  	{},
  };
  MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  
  MODULE_ALIAS("acpi");
  