drivers/cpufreq/ia64-acpi-cpufreq.c - kernel/common - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * This file provides the ACPI based P-state support. This
  * module works with generic cpufreq infrastructure. Most of
  * the code is based on i386 version
  * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
  *
  * Copyright (C) 2005 Intel Corp
  *      Venkatesh Pallipadi <[email protected]>
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/cpufreq.h>
 #include <linux/proc_fs.h>
 #include <asm/io.h>
 #include <linux/uaccess.h>
 #include <asm/pal.h>

 #include <linux/acpi.h>
 #include <acpi/processor.h>

 MODULE_AUTHOR("Venkatesh Pallipadi");
 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
 MODULE_LICENSE("GPL");

 struct cpufreq_acpi_io {
 	struct acpi_processor_performance	acpi_data;
 	unsigned int				resume;
 };

 struct cpufreq_acpi_req {
 	unsigned int		cpu;
 	unsigned int		state;
 };

 static struct cpufreq_acpi_io	*acpi_io_data[NR_CPUS];

 static struct cpufreq_driver acpi_cpufreq_driver;


 static int
 processor_set_pstate (
 	u32	value)
 {
 	s64 retval;

 	pr_debug("processor_set_pstate\n");

 	retval = ia64_pal_set_pstate((u64)value);

 	if (retval) {
 		pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
 		        value, retval);
 		return -ENODEV;
 	}
 	return (int)retval;
 }


 static int
 processor_get_pstate (
 	u32	*value)
 {
 	u64	pstate_index = 0;
 	s64 	retval;

 	pr_debug("processor_get_pstate\n");

 	retval = ia64_pal_get_pstate(&pstate_index,
 	                             PAL_GET_PSTATE_TYPE_INSTANT);
 	*value = (u32) pstate_index;

 	if (retval)
 		pr_debug("Failed to get current freq with "
 			"error 0x%lx, idx 0x%x\n", retval, *value);

 	return (int)retval;
 }


 /* To be used only after data->acpi_data is initialized */
 static unsigned
 extract_clock (
 	struct cpufreq_acpi_io *data,
 	unsigned value)
 {
 	unsigned long i;

 	pr_debug("extract_clock\n");

 	for (i = 0; i < data->acpi_data.state_count; i++) {
 		if (value == data->acpi_data.states[i].status)
 			return data->acpi_data.states[i].core_frequency;
 	}
 	return data->acpi_data.states[i-1].core_frequency;
 }


 static long
 processor_get_freq (
 	void *arg)
 {
 	struct cpufreq_acpi_req *req = arg;
 	unsigned int		cpu = req->cpu;
 	struct cpufreq_acpi_io	*data = acpi_io_data[cpu];
 	u32			value;
 	int			ret;

 	pr_debug("processor_get_freq\n");
 	if (smp_processor_id() != cpu)
 		return -EAGAIN;

 	/* processor_get_pstate gets the instantaneous frequency */
 	ret = processor_get_pstate(&value);
 	if (ret) {
 		pr_warn("get performance failed with error %d\n", ret);
 		return ret;
 	}
 	return 1000 * extract_clock(data, value);
 }


 static long
 processor_set_freq (
 	void *arg)
 {
 	struct cpufreq_acpi_req *req = arg;
 	unsigned int		cpu = req->cpu;
 	struct cpufreq_acpi_io	*data = acpi_io_data[cpu];
 	int			ret, state = req->state;
 	u32			value;

 	pr_debug("processor_set_freq\n");
 	if (smp_processor_id() != cpu)
 		return -EAGAIN;

 	if (state == data->acpi_data.state) {
 		if (unlikely(data->resume)) {
 			pr_debug("Called after resume, resetting to P%d\n", state);
 			data->resume = 0;
 		} else {
 			pr_debug("Already at target state (P%d)\n", state);
 			return 0;
 		}
 	}

 	pr_debug("Transitioning from P%d to P%d\n",
 		data->acpi_data.state, state);

 	/*
 	 * First we write the target state's 'control' value to the
 	 * control_register.
 	 */
 	value = (u32) data->acpi_data.states[state].control;

 	pr_debug("Transitioning to state: 0x%08x\n", value);

 	ret = processor_set_pstate(value);
 	if (ret) {
 		pr_warn("Transition failed with error %d\n", ret);
 		return -ENODEV;
 	}

 	data->acpi_data.state = state;
 	return 0;
 }


 static unsigned int
 acpi_cpufreq_get (
 	unsigned int		cpu)
 {
 	struct cpufreq_acpi_req req;
 	long ret;

 	req.cpu = cpu;
 	ret = work_on_cpu(cpu, processor_get_freq, &req);

 	return ret > 0 ? (unsigned int) ret : 0;
 }


 static int
 acpi_cpufreq_target (
 	struct cpufreq_policy   *policy,
 	unsigned int index)
 {
 	struct cpufreq_acpi_req req;

 	req.cpu = policy->cpu;
 	req.state = index;

 	return work_on_cpu(req.cpu, processor_set_freq, &req);
 }

 static int
 acpi_cpufreq_cpu_init (
 	struct cpufreq_policy   *policy)
 {
 	unsigned int		i;
 	unsigned int		cpu = policy->cpu;
 	struct cpufreq_acpi_io	*data;
 	unsigned int		result = 0;
 	struct cpufreq_frequency_table *freq_table;

 	pr_debug("acpi_cpufreq_cpu_init\n");

 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return (-ENOMEM);

 	acpi_io_data[cpu] = data;

 	result = acpi_processor_register_performance(&data->acpi_data, cpu);

 	if (result)
 		goto err_free;

 	/* capability check */
 	if (data->acpi_data.state_count <= 1) {
 		pr_debug("No P-States\n");
 		result = -ENODEV;
 		goto err_unreg;
 	}

 	if ((data->acpi_data.control_register.space_id !=
 					ACPI_ADR_SPACE_FIXED_HARDWARE) ||
 	    (data->acpi_data.status_register.space_id !=
 					ACPI_ADR_SPACE_FIXED_HARDWARE)) {
 		pr_debug("Unsupported address space [%d, %d]\n",
 			(u32) (data->acpi_data.control_register.space_id),
 			(u32) (data->acpi_data.status_register.space_id));
 		result = -ENODEV;
 		goto err_unreg;
 	}

 	/* alloc freq_table */
 	freq_table = kcalloc(data->acpi_data.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<data->acpi_data.state_count; i++) {
 		if ((data->acpi_data.states[i].transition_latency * 1000) >
 		    policy->cpuinfo.transition_latency) {
 			policy->cpuinfo.transition_latency =
 			    data->acpi_data.states[i].transition_latency * 1000;
 		}
 	}

 	/* table init */
 	for (i = 0; i <= data->acpi_data.state_count; i++)
 	{
 		if (i < data->acpi_data.state_count) {
 			freq_table[i].frequency =
 			      data->acpi_data.states[i].core_frequency * 1000;
 		} else {
 			freq_table[i].frequency = CPUFREQ_TABLE_END;
 		}
 	}

 	policy->freq_table = freq_table;

 	/* notify BIOS that we exist */
 	acpi_processor_notify_smm(THIS_MODULE);

 	pr_info("CPU%u - ACPI performance management activated\n", cpu);

 	for (i = 0; i < data->acpi_data.state_count; i++)
 		pr_debug("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
 			(i == data->acpi_data.state?'*':' '), i,
 			(u32) data->acpi_data.states[i].core_frequency,
 			(u32) data->acpi_data.states[i].power,
 			(u32) data->acpi_data.states[i].transition_latency,
 			(u32) data->acpi_data.states[i].bus_master_latency,
 			(u32) data->acpi_data.states[i].status,
 			(u32) data->acpi_data.states[i].control);

 	/* the first call to ->target() should result in us actually
 	 * writing something to the appropriate registers. */
 	data->resume = 1;

 	return (result);

  err_unreg:
 	acpi_processor_unregister_performance(cpu);
  err_free:
 	kfree(data);
 	acpi_io_data[cpu] = NULL;

 	return (result);
 }


 static int
 acpi_cpufreq_cpu_exit (
 	struct cpufreq_policy   *policy)
 {
 	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];

 	pr_debug("acpi_cpufreq_cpu_exit\n");

 	if (data) {
 		acpi_io_data[policy->cpu] = NULL;
 		acpi_processor_unregister_performance(policy->cpu);
 		kfree(policy->freq_table);
 		kfree(data);
 	}

 	return (0);
 }


 static struct cpufreq_driver acpi_cpufreq_driver = {
 	.verify 	= cpufreq_generic_frequency_table_verify,
 	.target_index	= acpi_cpufreq_target,
 	.get 		= acpi_cpufreq_get,
 	.init		= acpi_cpufreq_cpu_init,
 	.exit		= acpi_cpufreq_cpu_exit,
 	.name		= "acpi-cpufreq",
 	.attr		= cpufreq_generic_attr,
 };


 static int __init
 acpi_cpufreq_init (void)
 {
 	pr_debug("acpi_cpufreq_init\n");

  	return cpufreq_register_driver(&acpi_cpufreq_driver);
 }


 static void __exit
 acpi_cpufreq_exit (void)
 {
 	pr_debug("acpi_cpufreq_exit\n");

 	cpufreq_unregister_driver(&acpi_cpufreq_driver);
 }

 late_initcall(acpi_cpufreq_init);
 module_exit(acpi_cpufreq_exit);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* This file provides the ACPI based P-state support. This
	* module works with generic cpufreq infrastructure. Most of
	* the code is based on i386 version
	* (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
	*
	* Copyright (C) 2005 Intel Corp
	* Venkatesh Pallipadi <[email protected]>
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/cpufreq.h>
	#include <linux/proc_fs.h>
	#include <asm/io.h>
	#include <linux/uaccess.h>
	#include <asm/pal.h>

	#include <linux/acpi.h>
	#include <acpi/processor.h>

	MODULE_AUTHOR("Venkatesh Pallipadi");
	MODULE_DESCRIPTION("ACPI Processor P-States Driver");
	MODULE_LICENSE("GPL");

	struct cpufreq_acpi_io {
	struct acpi_processor_performance acpi_data;
	unsigned int resume;
	};

	struct cpufreq_acpi_req {
	unsigned int cpu;
	unsigned int state;
	};

	static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];

	static struct cpufreq_driver acpi_cpufreq_driver;


	static int
	processor_set_pstate (
	u32 value)
	{
	s64 retval;

	pr_debug("processor_set_pstate\n");

	retval = ia64_pal_set_pstate((u64)value);

	if (retval) {
	pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
	value, retval);
	return -ENODEV;
	}
	return (int)retval;
	}


	static int
	processor_get_pstate (
	u32 *value)
	{
	u64 pstate_index = 0;
	s64 retval;

	pr_debug("processor_get_pstate\n");

	retval = ia64_pal_get_pstate(&pstate_index,
	PAL_GET_PSTATE_TYPE_INSTANT);
	*value = (u32) pstate_index;

	if (retval)
	pr_debug("Failed to get current freq with "
	"error 0x%lx, idx 0x%x\n", retval, *value);

	return (int)retval;
	}


	/* To be used only after data->acpi_data is initialized */
	static unsigned
	extract_clock (
	struct cpufreq_acpi_io *data,
	unsigned value)
	{
	unsigned long i;

	pr_debug("extract_clock\n");

	for (i = 0; i < data->acpi_data.state_count; i++) {
	if (value == data->acpi_data.states[i].status)
	return data->acpi_data.states[i].core_frequency;
	}
	return data->acpi_data.states[i-1].core_frequency;
	}


	static long
	processor_get_freq (
	void *arg)
	{
	struct cpufreq_acpi_req *req = arg;
	unsigned int cpu = req->cpu;
	struct cpufreq_acpi_io *data = acpi_io_data[cpu];
	u32 value;
	int ret;

	pr_debug("processor_get_freq\n");
	if (smp_processor_id() != cpu)
	return -EAGAIN;

	/* processor_get_pstate gets the instantaneous frequency */
	ret = processor_get_pstate(&value);
	if (ret) {
	pr_warn("get performance failed with error %d\n", ret);
	return ret;
	}
	return 1000 * extract_clock(data, value);
	}


	static long
	processor_set_freq (
	void *arg)
	{
	struct cpufreq_acpi_req *req = arg;
	unsigned int cpu = req->cpu;
	struct cpufreq_acpi_io *data = acpi_io_data[cpu];
	int ret, state = req->state;
	u32 value;

	pr_debug("processor_set_freq\n");
	if (smp_processor_id() != cpu)
	return -EAGAIN;

	if (state == data->acpi_data.state) {
	if (unlikely(data->resume)) {
	pr_debug("Called after resume, resetting to P%d\n", state);
	data->resume = 0;
	} else {
	pr_debug("Already at target state (P%d)\n", state);
	return 0;
	}
	}

	pr_debug("Transitioning from P%d to P%d\n",
	data->acpi_data.state, state);

	/*
	* First we write the target state's 'control' value to the
	* control_register.
	*/
	value = (u32) data->acpi_data.states[state].control;

	pr_debug("Transitioning to state: 0x%08x\n", value);

	ret = processor_set_pstate(value);
	if (ret) {
	pr_warn("Transition failed with error %d\n", ret);
	return -ENODEV;
	}

	data->acpi_data.state = state;
	return 0;
	}


	static unsigned int
	acpi_cpufreq_get (
	unsigned int cpu)
	{
	struct cpufreq_acpi_req req;
	long ret;

	req.cpu = cpu;
	ret = work_on_cpu(cpu, processor_get_freq, &req);

	return ret > 0 ? (unsigned int) ret : 0;
	}


	static int
	acpi_cpufreq_target (
	struct cpufreq_policy *policy,
	unsigned int index)
	{
	struct cpufreq_acpi_req req;

	req.cpu = policy->cpu;
	req.state = index;

	return work_on_cpu(req.cpu, processor_set_freq, &req);
	}

	static int
	acpi_cpufreq_cpu_init (
	struct cpufreq_policy *policy)
	{
	unsigned int i;
	unsigned int cpu = policy->cpu;
	struct cpufreq_acpi_io *data;
	unsigned int result = 0;
	struct cpufreq_frequency_table *freq_table;

	pr_debug("acpi_cpufreq_cpu_init\n");

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
	return (-ENOMEM);

	acpi_io_data[cpu] = data;

	result = acpi_processor_register_performance(&data->acpi_data, cpu);

	if (result)
	goto err_free;

	/* capability check */
	if (data->acpi_data.state_count <= 1) {
	pr_debug("No P-States\n");
	result = -ENODEV;
	goto err_unreg;
	}

	if ((data->acpi_data.control_register.space_id !=
	ACPI_ADR_SPACE_FIXED_HARDWARE) \|\|
	(data->acpi_data.status_register.space_id !=
	ACPI_ADR_SPACE_FIXED_HARDWARE)) {
	pr_debug("Unsupported address space [%d, %d]\n",
	(u32) (data->acpi_data.control_register.space_id),
	(u32) (data->acpi_data.status_register.space_id));
	result = -ENODEV;
	goto err_unreg;
	}

	/* alloc freq_table */
	freq_table = kcalloc(data->acpi_data.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<data->acpi_data.state_count; i++) {
	if ((data->acpi_data.states[i].transition_latency * 1000) >
	policy->cpuinfo.transition_latency) {
	policy->cpuinfo.transition_latency =
	data->acpi_data.states[i].transition_latency * 1000;
	}
	}

	/* table init */
	for (i = 0; i <= data->acpi_data.state_count; i++)
	{
	if (i < data->acpi_data.state_count) {
	freq_table[i].frequency =
	data->acpi_data.states[i].core_frequency * 1000;
	} else {
	freq_table[i].frequency = CPUFREQ_TABLE_END;
	}
	}

	policy->freq_table = freq_table;

	/* notify BIOS that we exist */
	acpi_processor_notify_smm(THIS_MODULE);

	pr_info("CPU%u - ACPI performance management activated\n", cpu);

	for (i = 0; i < data->acpi_data.state_count; i++)
	pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
	(i == data->acpi_data.state?'*':' '), i,
	(u32) data->acpi_data.states[i].core_frequency,
	(u32) data->acpi_data.states[i].power,
	(u32) data->acpi_data.states[i].transition_latency,
	(u32) data->acpi_data.states[i].bus_master_latency,
	(u32) data->acpi_data.states[i].status,
	(u32) data->acpi_data.states[i].control);

	/* the first call to ->target() should result in us actually
	* writing something to the appropriate registers. */
	data->resume = 1;

	return (result);

	err_unreg:
	acpi_processor_unregister_performance(cpu);
	err_free:
	kfree(data);
	acpi_io_data[cpu] = NULL;

	return (result);
	}


	static int
	acpi_cpufreq_cpu_exit (
	struct cpufreq_policy *policy)
	{
	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];

	pr_debug("acpi_cpufreq_cpu_exit\n");

	if (data) {
	acpi_io_data[policy->cpu] = NULL;
	acpi_processor_unregister_performance(policy->cpu);
	kfree(policy->freq_table);
	kfree(data);
	}

	return (0);
	}


	static struct cpufreq_driver acpi_cpufreq_driver = {
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = acpi_cpufreq_target,
	.get = acpi_cpufreq_get,
	.init = acpi_cpufreq_cpu_init,
	.exit = acpi_cpufreq_cpu_exit,
	.name = "acpi-cpufreq",
	.attr = cpufreq_generic_attr,
	};


	static int __init
	acpi_cpufreq_init (void)
	{
	pr_debug("acpi_cpufreq_init\n");

	return cpufreq_register_driver(&acpi_cpufreq_driver);
	}


	static void __exit
	acpi_cpufreq_exit (void)
	{
	pr_debug("acpi_cpufreq_exit\n");

	cpufreq_unregister_driver(&acpi_cpufreq_driver);
	}

	late_initcall(acpi_cpufreq_init);
	module_exit(acpi_cpufreq_exit);