[deliverable/linux.git] / drivers / cpufreq / cppc_cpufreq.c

/*
 * CPPC (Collaborative Processor Performance Control) driver for
 * interfacing with the CPUfreq layer and governors. See
 * cppc_acpi.c for CPPC specific methods.
 *
 * (C) Copyright 2014, 2015 Linaro Ltd.
 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#define pr_fmt(fmt)	"CPPC Cpufreq:"	fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/vmalloc.h>

#include <acpi/cppc_acpi.h>

/*
 * These structs contain information parsed from per CPU
 * ACPI _CPC structures.
 * e.g. For each CPU the highest, lowest supported
 * performance capabilities, desired performance level
 * requested etc.
 */
static struct cpudata **all_cpu_data;

static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
		unsigned int target_freq,
		unsigned int relation)
{
	struct cpudata *cpu;
	struct cpufreq_freqs freqs;
	int ret = 0;

	cpu = all_cpu_data[policy->cpu];

	cpu->perf_ctrls.desired_perf = target_freq;
	freqs.old = policy->cur;
	freqs.new = target_freq;

	cpufreq_freq_transition_begin(policy, &freqs);
	ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls);
	cpufreq_freq_transition_end(policy, &freqs, ret != 0);

	if (ret)
		pr_debug("Failed to set target on CPU:%d. ret:%d\n",
				cpu->cpu, ret);

	return ret;
}

static int cppc_verify_policy(struct cpufreq_policy *policy)
{
	cpufreq_verify_within_cpu_limits(policy);
	return 0;
}

static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
{
	int cpu_num = policy->cpu;
	struct cpudata *cpu = all_cpu_data[cpu_num];
	int ret;

	cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;

	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
	if (ret)
		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
				cpu->perf_caps.lowest_perf, cpu_num, ret);
}

static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	struct cpudata *cpu;
	unsigned int cpu_num = policy->cpu;
	int ret = 0;

	cpu = all_cpu_data[policy->cpu];

	cpu->cpu = cpu_num;
	ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps);

	if (ret) {
		pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
				cpu_num, ret);
		return ret;
	}

	policy->min = cpu->perf_caps.lowest_perf;
	policy->max = cpu->perf_caps.highest_perf;
	policy->cpuinfo.min_freq = policy->min;
	policy->cpuinfo.max_freq = policy->max;
	policy->shared_type = cpu->shared_type;

	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
		cpumask_copy(policy->cpus, cpu->shared_cpu_map);
	else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) {
		/* Support only SW_ANY for now. */
		pr_debug("Unsupported CPU co-ord type\n");
		return -EFAULT;
	}

	cpumask_set_cpu(policy->cpu, policy->cpus);
	cpu->cur_policy = policy;

	/* Set policy->cur to max now. The governors will adjust later. */
	policy->cur = cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;

	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
	if (ret)
		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
				cpu->perf_caps.highest_perf, cpu_num, ret);

	return ret;
}

static struct cpufreq_driver cppc_cpufreq_driver = {
	.flags = CPUFREQ_CONST_LOOPS,
	.verify = cppc_verify_policy,
	.target = cppc_cpufreq_set_target,
	.init = cppc_cpufreq_cpu_init,
	.stop_cpu = cppc_cpufreq_stop_cpu,
	.name = "cppc_cpufreq",
};

static int __init cppc_cpufreq_init(void)
{
	int i, ret = 0;
	struct cpudata *cpu;

	if (acpi_disabled)
		return -ENODEV;

	all_cpu_data = kzalloc(sizeof(void *) * num_possible_cpus(), GFP_KERNEL);
	if (!all_cpu_data)
		return -ENOMEM;

	for_each_possible_cpu(i) {
		all_cpu_data[i] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
		if (!all_cpu_data[i])
			goto out;

		cpu = all_cpu_data[i];
		if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))
			goto out;
	}

	ret = acpi_get_psd_map(all_cpu_data);
	if (ret) {
		pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");
		goto out;
	}

	ret = cpufreq_register_driver(&cppc_cpufreq_driver);
	if (ret)
		goto out;

	return ret;

out:
	for_each_possible_cpu(i)
		kfree(all_cpu_data[i]);

	kfree(all_cpu_data);
	return -ENODEV;
}

static void __exit cppc_cpufreq_exit(void)
{
	struct cpudata *cpu;
	int i;

	cpufreq_unregister_driver(&cppc_cpufreq_driver);

	for_each_possible_cpu(i) {
		cpu = all_cpu_data[i];
		free_cpumask_var(cpu->shared_cpu_map);
		kfree(cpu);
	}

	kfree(all_cpu_data);
}

module_exit(cppc_cpufreq_exit);
MODULE_AUTHOR("Ashwin Chaugule");
MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
MODULE_LICENSE("GPL");

late_initcall(cppc_cpufreq_init);
Commit	Line	Data
5477fb3b AC	1	/*
	2	* CPPC (Collaborative Processor Performance Control) driver for
	3	* interfacing with the CPUfreq layer and governors. See
	4	* cppc_acpi.c for CPPC specific methods.
	5	*
	6	* (C) Copyright 2014, 2015 Linaro Ltd.
	7	* Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; version 2
	12	* of the License.
	13	*/
	14
	15	#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
	16
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/delay.h>
	20	#include <linux/cpu.h>
	21	#include <linux/cpufreq.h>
	22	#include <linux/vmalloc.h>
	23
	24	#include <acpi/cppc_acpi.h>
	25
	26	/*
	27	* These structs contain information parsed from per CPU
	28	* ACPI _CPC structures.
	29	* e.g. For each CPU the highest, lowest supported
	30	* performance capabilities, desired performance level
	31	* requested etc.
	32	*/
	33	static struct cpudata **all_cpu_data;
	34
	35	static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
	36	unsigned int target_freq,
	37	unsigned int relation)
	38	{
	39	struct cpudata *cpu;
	40	struct cpufreq_freqs freqs;
	41	int ret = 0;
	42
	43	cpu = all_cpu_data[policy->cpu];
	44
	45	cpu->perf_ctrls.desired_perf = target_freq;
	46	freqs.old = policy->cur;
	47	freqs.new = target_freq;
	48
	49	cpufreq_freq_transition_begin(policy, &freqs);
	50	ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls);
	51	cpufreq_freq_transition_end(policy, &freqs, ret != 0);
	52
	53	if (ret)
	54	pr_debug("Failed to set target on CPU:%d. ret:%d\n",
	55	cpu->cpu, ret);
	56
	57	return ret;
	58	}
	59
	60	static int cppc_verify_policy(struct cpufreq_policy *policy)
	61	{
	62	cpufreq_verify_within_cpu_limits(policy);
	63	return 0;
	64	}
65
66	static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
67	{
68	int cpu_num = policy->cpu;
69	struct cpudata *cpu = all_cpu_data[cpu_num];
70	int ret;
71
72	cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;
73
74	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
75	if (ret)
76	pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
77	cpu->perf_caps.lowest_perf, cpu_num, ret);
78	}
79
80	static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
81	{
82	struct cpudata *cpu;
83	unsigned int cpu_num = policy->cpu;
84	int ret = 0;
85
86	cpu = all_cpu_data[policy->cpu];
87
88	cpu->cpu = cpu_num;
89	ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps);
90
91	if (ret) {
92	pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
93	cpu_num, ret);
94	return ret;
95	}
96
97	policy->min = cpu->perf_caps.lowest_perf;
98	policy->max = cpu->perf_caps.highest_perf;
99	policy->cpuinfo.min_freq = policy->min;
100	policy->cpuinfo.max_freq = policy->max;
9dc17917	101	policy->shared_type = cpu->shared_type;
5477fb3b AC	102
	103	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
	104	cpumask_copy(policy->cpus, cpu->shared_cpu_map);
9dc17917	105	else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) {
5477fb3b AC	106	/* Support only SW_ANY for now. */
	107	pr_debug("Unsupported CPU co-ord type\n");
	108	return -EFAULT;
	109	}
	110
	111	cpumask_set_cpu(policy->cpu, policy->cpus);
	112	cpu->cur_policy = policy;
	113
	114	/* Set policy->cur to max now. The governors will adjust later. */
	115	policy->cur = cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
	116
	117	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
	118	if (ret)
	119	pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
	120	cpu->perf_caps.highest_perf, cpu_num, ret);
	121
	122	return ret;
	123	}
	124
	125	static struct cpufreq_driver cppc_cpufreq_driver = {
	126	.flags = CPUFREQ_CONST_LOOPS,
	127	.verify = cppc_verify_policy,
	128	.target = cppc_cpufreq_set_target,
	129	.init = cppc_cpufreq_cpu_init,
	130	.stop_cpu = cppc_cpufreq_stop_cpu,
	131	.name = "cppc_cpufreq",
	132	};
	133
	134	static int __init cppc_cpufreq_init(void)
	135	{
	136	int i, ret = 0;
	137	struct cpudata *cpu;
	138
	139	if (acpi_disabled)
	140	return -ENODEV;
	141
	142	all_cpu_data = kzalloc(sizeof(void ) num_possible_cpus(), GFP_KERNEL);
	143	if (!all_cpu_data)
	144	return -ENOMEM;
	145
	146	for_each_possible_cpu(i) {
	147	all_cpu_data[i] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
	148	if (!all_cpu_data[i])
	149	goto out;
	150
	151	cpu = all_cpu_data[i];
	152	if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))
	153	goto out;
	154	}
	155
	156	ret = acpi_get_psd_map(all_cpu_data);
	157	if (ret) {
	158	pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");
	159	goto out;
	160	}
	161
	162	ret = cpufreq_register_driver(&cppc_cpufreq_driver);
	163	if (ret)
	164	goto out;
	165
	166	return ret;
	167
	168	out:
	169	for_each_possible_cpu(i)
efb2d3be	170	kfree(all_cpu_data[i]);
5477fb3b AC	171
	172	kfree(all_cpu_data);
	173	return -ENODEV;
	174	}
	175
a29a1e76 AC	176	static void __exit cppc_cpufreq_exit(void)
	177	{
	178	struct cpudata *cpu;
	179	int i;
	180
	181	cpufreq_unregister_driver(&cppc_cpufreq_driver);
	182
	183	for_each_possible_cpu(i) {
	184	cpu = all_cpu_data[i];
	185	free_cpumask_var(cpu->shared_cpu_map);
	186	kfree(cpu);
	187	}
	188
	189	kfree(all_cpu_data);
	190	}
	191
	192	module_exit(cppc_cpufreq_exit);
	193	MODULE_AUTHOR("Ashwin Chaugule");
	194	MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
	195	MODULE_LICENSE("GPL");
	196
5477fb3b	197	late_initcall(cppc_cpufreq_init);