1 files changed, 1072 insertions, 0 deletions

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
new file mode 100644
index 000000000..d1bbc16fb
--- /dev/null
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -0,0 +1,1072 @@
+// 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");