[thirdparty/kernel/stable.git] / drivers / base / arch_topology.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Arch specific cpu topology information
 *
 * Copyright (C) 2016, ARM Ltd.
 * Written by: Juri Lelli, ARM Ltd.
 */

#include <linux/acpi.h>
#include <linux/arch_topology.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sched/topology.h>
#include <linux/cpuset.h>

DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;

void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
			 unsigned long max_freq)
{
	unsigned long scale;
	int i;

	scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;

	for_each_cpu(i, cpus)
		per_cpu(freq_scale, i) = scale;
}

static DEFINE_MUTEX(cpu_scale_mutex);
DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;

void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
{
	per_cpu(cpu_scale, cpu) = capacity;
}

static ssize_t cpu_capacity_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct cpu *cpu = container_of(dev, struct cpu, dev);

	return sprintf(buf, "%lu\n", topology_get_cpu_scale(NULL, cpu->dev.id));
}

static void update_topology_flags_workfn(struct work_struct *work);
static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);

static ssize_t cpu_capacity_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t count)
{
	struct cpu *cpu = container_of(dev, struct cpu, dev);
	int this_cpu = cpu->dev.id;
	int i;
	unsigned long new_capacity;
	ssize_t ret;

	if (!count)
		return 0;

	ret = kstrtoul(buf, 0, &new_capacity);
	if (ret)
		return ret;
	if (new_capacity > SCHED_CAPACITY_SCALE)
		return -EINVAL;

	mutex_lock(&cpu_scale_mutex);
	for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
		topology_set_cpu_scale(i, new_capacity);
	mutex_unlock(&cpu_scale_mutex);

	schedule_work(&update_topology_flags_work);

	return count;
}

static DEVICE_ATTR_RW(cpu_capacity);

static int register_cpu_capacity_sysctl(void)
{
	int i;
	struct device *cpu;

	for_each_possible_cpu(i) {
		cpu = get_cpu_device(i);
		if (!cpu) {
			pr_err("%s: too early to get CPU%d device!\n",
			       __func__, i);
			continue;
		}
		device_create_file(cpu, &dev_attr_cpu_capacity);
	}

	return 0;
}
subsys_initcall(register_cpu_capacity_sysctl);

static int update_topology;

int topology_update_cpu_topology(void)
{
	return update_topology;
}

/*
 * Updating the sched_domains can't be done directly from cpufreq callbacks
 * due to locking, so queue the work for later.
 */
static void update_topology_flags_workfn(struct work_struct *work)
{
	update_topology = 1;
	rebuild_sched_domains();
	pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
	update_topology = 0;
}

static u32 capacity_scale;
static u32 *raw_capacity;

static int free_raw_capacity(void)
{
	kfree(raw_capacity);
	raw_capacity = NULL;

	return 0;
}

void topology_normalize_cpu_scale(void)
{
	u64 capacity;
	int cpu;

	if (!raw_capacity)
		return;

	pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
	mutex_lock(&cpu_scale_mutex);
	for_each_possible_cpu(cpu) {
		pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
			 cpu, raw_capacity[cpu]);
		capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
			/ capacity_scale;
		topology_set_cpu_scale(cpu, capacity);
		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
			cpu, topology_get_cpu_scale(NULL, cpu));
	}
	mutex_unlock(&cpu_scale_mutex);
}

bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
{
	static bool cap_parsing_failed;
	int ret;
	u32 cpu_capacity;

	if (cap_parsing_failed)
		return false;

	ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
				   &cpu_capacity);
	if (!ret) {
		if (!raw_capacity) {
			raw_capacity = kcalloc(num_possible_cpus(),
					       sizeof(*raw_capacity),
					       GFP_KERNEL);
			if (!raw_capacity) {
				pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
				cap_parsing_failed = true;
				return false;
			}
		}
		capacity_scale = max(cpu_capacity, capacity_scale);
		raw_capacity[cpu] = cpu_capacity;
		pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
			cpu_node, raw_capacity[cpu]);
	} else {
		if (raw_capacity) {
			pr_err("cpu_capacity: missing %pOF raw capacity\n",
				cpu_node);
			pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
		}
		cap_parsing_failed = true;
		free_raw_capacity();
	}

	return !ret;
}

#ifdef CONFIG_CPU_FREQ
static cpumask_var_t cpus_to_visit;
static void parsing_done_workfn(struct work_struct *work);
static DECLARE_WORK(parsing_done_work, parsing_done_workfn);

static int
init_cpu_capacity_callback(struct notifier_block *nb,
			   unsigned long val,
			   void *data)
{
	struct cpufreq_policy *policy = data;
	int cpu;

	if (!raw_capacity)
		return 0;

	if (val != CPUFREQ_NOTIFY)
		return 0;

	pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
		 cpumask_pr_args(policy->related_cpus),
		 cpumask_pr_args(cpus_to_visit));

	cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);

	for_each_cpu(cpu, policy->related_cpus) {
		raw_capacity[cpu] = topology_get_cpu_scale(NULL, cpu) *
				    policy->cpuinfo.max_freq / 1000UL;
		capacity_scale = max(raw_capacity[cpu], capacity_scale);
	}

	if (cpumask_empty(cpus_to_visit)) {
		topology_normalize_cpu_scale();
		schedule_work(&update_topology_flags_work);
		free_raw_capacity();
		pr_debug("cpu_capacity: parsing done\n");
		schedule_work(&parsing_done_work);
	}

	return 0;
}

static struct notifier_block init_cpu_capacity_notifier = {
	.notifier_call = init_cpu_capacity_callback,
};

static int __init register_cpufreq_notifier(void)
{
	int ret;

	/*
	 * on ACPI-based systems we need to use the default cpu capacity
	 * until we have the necessary code to parse the cpu capacity, so
	 * skip registering cpufreq notifier.
	 */
	if (!acpi_disabled || !raw_capacity)
		return -EINVAL;

	if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
		pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
		return -ENOMEM;
	}

	cpumask_copy(cpus_to_visit, cpu_possible_mask);

	ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
					CPUFREQ_POLICY_NOTIFIER);

	if (ret)
		free_cpumask_var(cpus_to_visit);

	return ret;
}
core_initcall(register_cpufreq_notifier);

static void parsing_done_workfn(struct work_struct *work)
{
	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
					 CPUFREQ_POLICY_NOTIFIER);
	free_cpumask_var(cpus_to_visit);
}

#else
core_initcall(free_raw_capacity);
#endif
Commit	Line	Data
6ee97d35	1	// SPDX-License-Identifier: GPL-2.0
2ef7a295 JL	2	/*
	3	* Arch specific cpu topology information
	4	*
	5	* Copyright (C) 2016, ARM Ltd.
	6	* Written by: Juri Lelli, ARM Ltd.
2ef7a295 JL	7	*/
	8
	9	#include <linux/acpi.h>
615ffd63	10	#include <linux/arch_topology.h>
2ef7a295 JL	11	#include <linux/cpu.h>
	12	#include <linux/cpufreq.h>
	13	#include <linux/device.h>
	14	#include <linux/of.h>
	15	#include <linux/slab.h>
	16	#include <linux/string.h>
	17	#include <linux/sched/topology.h>
bb1fbdd3	18	#include <linux/cpuset.h>
2ef7a295	19
0e27c567	20	DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;
2ef7a295	21
0e27c567 DE	22	void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
0e27c567 DE	23	unsigned long max_freq)
2ef7a295	24	{
0e27c567 DE	25	unsigned long scale;
	26	int i;
	27
	28	scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
	29
	30	for_each_cpu(i, cpus)
	31	per_cpu(freq_scale, i) = scale;
2ef7a295 JL	32	}
2ef7a295 JL	33
2ef7a295	34	static DEFINE_MUTEX(cpu_scale_mutex);
8216f588	35	DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
2ef7a295	36
4ca4f26a	37	void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
2ef7a295 JL	38	{
	39	per_cpu(cpu_scale, cpu) = capacity;
	40	}
	41
	42	static ssize_t cpu_capacity_show(struct device *dev,
	43	struct device_attribute *attr,
	44	char *buf)
	45	{
	46	struct cpu *cpu = container_of(dev, struct cpu, dev);
	47
3eeba1a2	48	return sprintf(buf, "%lu\n", topology_get_cpu_scale(NULL, cpu->dev.id));
2ef7a295 JL	49	}
2ef7a295 JL	50
bb1fbdd3 MR	51	static void update_topology_flags_workfn(struct work_struct *work);
	52	static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
	53
2ef7a295 JL	54	static ssize_t cpu_capacity_store(struct device *dev,
	55	struct device_attribute *attr,
	56	const char *buf,
	57	size_t count)
	58	{
	59	struct cpu *cpu = container_of(dev, struct cpu, dev);
	60	int this_cpu = cpu->dev.id;
	61	int i;
	62	unsigned long new_capacity;
	63	ssize_t ret;
	64
	65	if (!count)
	66	return 0;
	67
	68	ret = kstrtoul(buf, 0, &new_capacity);
	69	if (ret)
	70	return ret;
	71	if (new_capacity > SCHED_CAPACITY_SCALE)
	72	return -EINVAL;
	73
	74	mutex_lock(&cpu_scale_mutex);
	75	for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
4ca4f26a	76	topology_set_cpu_scale(i, new_capacity);
2ef7a295 JL	77	mutex_unlock(&cpu_scale_mutex);
2ef7a295 JL	78
bb1fbdd3 MR	79	schedule_work(&update_topology_flags_work);
bb1fbdd3 MR	80
2ef7a295 JL	81	return count;
	82	}
	83
	84	static DEVICE_ATTR_RW(cpu_capacity);
	85
	86	static int register_cpu_capacity_sysctl(void)
	87	{
	88	int i;
	89	struct device *cpu;
	90
	91	for_each_possible_cpu(i) {
	92	cpu = get_cpu_device(i);
	93	if (!cpu) {
	94	pr_err("%s: too early to get CPU%d device!\n",
	95	__func__, i);
	96	continue;
	97	}
	98	device_create_file(cpu, &dev_attr_cpu_capacity);
	99	}
	100
	101	return 0;
	102	}
	103	subsys_initcall(register_cpu_capacity_sysctl);
	104
bb1fbdd3 MR	105	static int update_topology;
	106
	107	int topology_update_cpu_topology(void)
	108	{
	109	return update_topology;
	110	}
	111
	112	/*
	113	* Updating the sched_domains can't be done directly from cpufreq callbacks
	114	* due to locking, so queue the work for later.
	115	*/
	116	static void update_topology_flags_workfn(struct work_struct *work)
	117	{
	118	update_topology = 1;
	119	rebuild_sched_domains();
	120	pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
	121	update_topology = 0;
	122	}
	123
2ef7a295 JL	124	static u32 capacity_scale;
2ef7a295 JL	125	static u32 *raw_capacity;
62de1161	126
82d8ba71	127	static int free_raw_capacity(void)
62de1161 VK	128	{
	129	kfree(raw_capacity);
	130	raw_capacity = NULL;
	131
	132	return 0;
	133	}
2ef7a295	134
4ca4f26a	135	void topology_normalize_cpu_scale(void)
2ef7a295 JL	136	{
	137	u64 capacity;
	138	int cpu;
	139
62de1161	140	if (!raw_capacity)
2ef7a295 JL	141	return;
	142
	143	pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
	144	mutex_lock(&cpu_scale_mutex);
	145	for_each_possible_cpu(cpu) {
	146	pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
	147	cpu, raw_capacity[cpu]);
	148	capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
	149	/ capacity_scale;
4ca4f26a	150	topology_set_cpu_scale(cpu, capacity);
2ef7a295	151	pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
4ca4f26a	152	cpu, topology_get_cpu_scale(NULL, cpu));
2ef7a295 JL	153	}
	154	mutex_unlock(&cpu_scale_mutex);
	155	}
	156
805df296	157	bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
2ef7a295	158	{
62de1161	159	static bool cap_parsing_failed;
805df296	160	int ret;
2ef7a295 JL	161	u32 cpu_capacity;
	162
	163	if (cap_parsing_failed)
805df296	164	return false;
2ef7a295	165
3eeba1a2	166	ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
2ef7a295 JL	167	&cpu_capacity);
	168	if (!ret) {
	169	if (!raw_capacity) {
	170	raw_capacity = kcalloc(num_possible_cpus(),
	171	sizeof(*raw_capacity),
	172	GFP_KERNEL);
	173	if (!raw_capacity) {
	174	pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
	175	cap_parsing_failed = true;
805df296	176	return false;
2ef7a295 JL	177	}
	178	}
	179	capacity_scale = max(cpu_capacity, capacity_scale);
	180	raw_capacity[cpu] = cpu_capacity;
6ef2541f RH	181	pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
6ef2541f RH	182	cpu_node, raw_capacity[cpu]);
2ef7a295 JL	183	} else {
2ef7a295 JL	184	if (raw_capacity) {
6ef2541f RH	185	pr_err("cpu_capacity: missing %pOF raw capacity\n",
6ef2541f RH	186	cpu_node);
2ef7a295 JL	187	pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
	188	}
	189	cap_parsing_failed = true;
62de1161	190	free_raw_capacity();
2ef7a295 JL	191	}
	192
	193	return !ret;
	194	}
	195
	196	#ifdef CONFIG_CPU_FREQ
9de9a449 GI	197	static cpumask_var_t cpus_to_visit;
	198	static void parsing_done_workfn(struct work_struct *work);
	199	static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
2ef7a295	200
9de9a449	201	static int
2ef7a295 JL	202	init_cpu_capacity_callback(struct notifier_block *nb,
	203	unsigned long val,
	204	void *data)
	205	{
	206	struct cpufreq_policy *policy = data;
	207	int cpu;
	208
d8bcf4db	209	if (!raw_capacity)
2ef7a295 JL	210	return 0;
2ef7a295 JL	211
93a57081 VK	212	if (val != CPUFREQ_NOTIFY)
	213	return 0;
	214
	215	pr_debug("cpu_capacity: init cpu capacity for CPUs [%pbl] (to_visit=%pbl)\n",
	216	cpumask_pr_args(policy->related_cpus),
	217	cpumask_pr_args(cpus_to_visit));
	218
	219	cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
	220
	221	for_each_cpu(cpu, policy->related_cpus) {
	222	raw_capacity[cpu] = topology_get_cpu_scale(NULL, cpu) *
	223	policy->cpuinfo.max_freq / 1000UL;
	224	capacity_scale = max(raw_capacity[cpu], capacity_scale);
2ef7a295	225	}
93a57081 VK	226
	227	if (cpumask_empty(cpus_to_visit)) {
	228	topology_normalize_cpu_scale();
bb1fbdd3	229	schedule_work(&update_topology_flags_work);
62de1161	230	free_raw_capacity();
93a57081	231	pr_debug("cpu_capacity: parsing done\n");
93a57081 VK	232	schedule_work(&parsing_done_work);
	233	}
	234
2ef7a295 JL	235	return 0;
	236	}
	237
9de9a449	238	static struct notifier_block init_cpu_capacity_notifier = {
2ef7a295 JL	239	.notifier_call = init_cpu_capacity_callback,
	240	};
	241
	242	static int __init register_cpufreq_notifier(void)
	243	{
5408211a DE	244	int ret;
5408211a DE	245
2ef7a295 JL	246	/*
	247	* on ACPI-based systems we need to use the default cpu capacity
	248	* until we have the necessary code to parse the cpu capacity, so
	249	* skip registering cpufreq notifier.
	250	*/
c105aa31	251	if (!acpi_disabled \|\| !raw_capacity)
2ef7a295 JL	252	return -EINVAL;
	253
	254	if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
	255	pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
	256	return -ENOMEM;
	257	}
	258
	259	cpumask_copy(cpus_to_visit, cpu_possible_mask);
	260
5408211a DE	261	ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
	262	CPUFREQ_POLICY_NOTIFIER);
	263
	264	if (ret)
	265	free_cpumask_var(cpus_to_visit);
	266
	267	return ret;
2ef7a295 JL	268	}
	269	core_initcall(register_cpufreq_notifier);
	270
9de9a449	271	static void parsing_done_workfn(struct work_struct *work)
2ef7a295 JL	272	{
	273	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
	274	CPUFREQ_POLICY_NOTIFIER);
5408211a	275	free_cpumask_var(cpus_to_visit);
2ef7a295 JL	276	}
	277
	278	#else
2ef7a295 JL	279	core_initcall(free_raw_capacity);
2ef7a295 JL	280	#endif