[mirror_ubuntu-zesty-kernel.git] / arch / arm64 / kernel / topology.c

/*
 * arch/arm64/kernel/topology.c
 *
 * Copyright (C) 2011,2013,2014 Linaro Limited.
 *
 * Based on the arm32 version written by Vincent Guittot in turn based on
 * arch/sh/kernel/topology.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/percpu.h>
#include <linux/node.h>
#include <linux/nodemask.h>
#include <linux/of.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/cpufreq.h>

#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/topology.h>

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

unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
{
	return per_cpu(cpu_scale, cpu);
}

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

#ifdef CONFIG_PROC_SYSCTL
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",
			arch_scale_cpu_capacity(NULL, cpu->dev.id));
}

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, i;
	unsigned long new_capacity;
	ssize_t ret;

	if (count) {
		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)
			set_capacity_scale(i, new_capacity);
		mutex_unlock(&cpu_scale_mutex);
	}

	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);
#endif

static u32 capacity_scale;
static u32 *raw_capacity;
static bool cap_parsing_failed;

static void __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
{
	int ret;
	u32 cpu_capacity;

	if (cap_parsing_failed)
		return;

	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;
			}
		}
		capacity_scale = max(cpu_capacity, capacity_scale);
		raw_capacity[cpu] = cpu_capacity;
		pr_debug("cpu_capacity: %s cpu_capacity=%u (raw)\n",
			cpu_node->full_name, raw_capacity[cpu]);
	} else {
		if (raw_capacity) {
			pr_err("cpu_capacity: missing %s raw capacity\n",
				cpu_node->full_name);
			pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
		}
		cap_parsing_failed = true;
		kfree(raw_capacity);
	}
}

static void normalize_cpu_capacity(void)
{
	u64 capacity;
	int cpu;

	if (!raw_capacity || cap_parsing_failed)
		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;
		set_capacity_scale(cpu, capacity);
		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
			cpu, arch_scale_cpu_capacity(NULL, cpu));
	}
	mutex_unlock(&cpu_scale_mutex);
}

#ifdef CONFIG_CPU_FREQ
static cpumask_var_t cpus_to_visit;
static bool cap_parsing_done;
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 (cap_parsing_failed || cap_parsing_done)
		return 0;

	switch (val) {
	case CPUFREQ_NOTIFY:
		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] = arch_scale_cpu_capacity(NULL, cpu) *
					    policy->cpuinfo.max_freq / 1000UL;
			capacity_scale = max(raw_capacity[cpu], capacity_scale);
		}
		if (cpumask_empty(cpus_to_visit)) {
			normalize_cpu_capacity();
			kfree(raw_capacity);
			pr_debug("cpu_capacity: parsing done\n");
			cap_parsing_done = true;
			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)
{
	/*
	 * 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 || cap_parsing_failed)
		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);

	return cpufreq_register_notifier(&init_cpu_capacity_notifier,
					 CPUFREQ_POLICY_NOTIFIER);
}
core_initcall(register_cpufreq_notifier);

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

#else
static int __init free_raw_capacity(void)
{
	kfree(raw_capacity);

	return 0;
}
core_initcall(free_raw_capacity);
#endif

static int __init get_cpu_for_node(struct device_node *node)
{
	struct device_node *cpu_node;
	int cpu;

	cpu_node = of_parse_phandle(node, "cpu", 0);
	if (!cpu_node)
		return -1;

	for_each_possible_cpu(cpu) {
		if (of_get_cpu_node(cpu, NULL) == cpu_node) {
			parse_cpu_capacity(cpu_node, cpu);
			of_node_put(cpu_node);
			return cpu;
		}
	}

	pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name);

	of_node_put(cpu_node);
	return -1;
}

static int __init parse_core(struct device_node *core, int cluster_id,
			     int core_id)
{
	char name[10];
	bool leaf = true;
	int i = 0;
	int cpu;
	struct device_node *t;

	do {
		snprintf(name, sizeof(name), "thread%d", i);
		t = of_get_child_by_name(core, name);
		if (t) {
			leaf = false;
			cpu = get_cpu_for_node(t);
			if (cpu >= 0) {
				cpu_topology[cpu].cluster_id = cluster_id;
				cpu_topology[cpu].core_id = core_id;
				cpu_topology[cpu].thread_id = i;
			} else {
				pr_err("%s: Can't get CPU for thread\n",
				       t->full_name);
				of_node_put(t);
				return -EINVAL;
			}
			of_node_put(t);
		}
		i++;
	} while (t);

	cpu = get_cpu_for_node(core);
	if (cpu >= 0) {
		if (!leaf) {
			pr_err("%s: Core has both threads and CPU\n",
			       core->full_name);
			return -EINVAL;
		}

		cpu_topology[cpu].cluster_id = cluster_id;
		cpu_topology[cpu].core_id = core_id;
	} else if (leaf) {
		pr_err("%s: Can't get CPU for leaf core\n", core->full_name);
		return -EINVAL;
	}

	return 0;
}

static int __init parse_cluster(struct device_node *cluster, int depth)
{
	char name[10];
	bool leaf = true;
	bool has_cores = false;
	struct device_node *c;
	static int cluster_id __initdata;
	int core_id = 0;
	int i, ret;

	/*
	 * First check for child clusters; we currently ignore any
	 * information about the nesting of clusters and present the
	 * scheduler with a flat list of them.
	 */
	i = 0;
	do {
		snprintf(name, sizeof(name), "cluster%d", i);
		c = of_get_child_by_name(cluster, name);
		if (c) {
			leaf = false;
			ret = parse_cluster(c, depth + 1);
			of_node_put(c);
			if (ret != 0)
				return ret;
		}
		i++;
	} while (c);

	/* Now check for cores */
	i = 0;
	do {
		snprintf(name, sizeof(name), "core%d", i);
		c = of_get_child_by_name(cluster, name);
		if (c) {
			has_cores = true;

			if (depth == 0) {
				pr_err("%s: cpu-map children should be clusters\n",
				       c->full_name);
				of_node_put(c);
				return -EINVAL;
			}

			if (leaf) {
				ret = parse_core(c, cluster_id, core_id++);
			} else {
				pr_err("%s: Non-leaf cluster with core %s\n",
				       cluster->full_name, name);
				ret = -EINVAL;
			}

			of_node_put(c);
			if (ret != 0)
				return ret;
		}
		i++;
	} while (c);

	if (leaf && !has_cores)
		pr_warn("%s: empty cluster\n", cluster->full_name);

	if (leaf)
		cluster_id++;

	return 0;
}

static int __init parse_dt_topology(void)
{
	struct device_node *cn, *map;
	int ret = 0;
	int cpu;

	cn = of_find_node_by_path("/cpus");
	if (!cn) {
		pr_err("No CPU information found in DT\n");
		return 0;
	}

	/*
	 * When topology is provided cpu-map is essentially a root
	 * cluster with restricted subnodes.
	 */
	map = of_get_child_by_name(cn, "cpu-map");
	if (!map) {
		cap_parsing_failed = true;
		goto out;
	}

	ret = parse_cluster(map, 0);
	if (ret != 0)
		goto out_map;

	normalize_cpu_capacity();

	/*
	 * Check that all cores are in the topology; the SMP code will
	 * only mark cores described in the DT as possible.
	 */
	for_each_possible_cpu(cpu)
		if (cpu_topology[cpu].cluster_id == -1)
			ret = -EINVAL;

out_map:
	of_node_put(map);
out:
	of_node_put(cn);
	return ret;
}

/*
 * cpu topology table
 */
struct cpu_topology cpu_topology[NR_CPUS];
EXPORT_SYMBOL_GPL(cpu_topology);

const struct cpumask *cpu_coregroup_mask(int cpu)
{
	return &cpu_topology[cpu].core_sibling;
}

static void update_siblings_masks(unsigned int cpuid)
{
	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
	int cpu;

	/* update core and thread sibling masks */
	for_each_possible_cpu(cpu) {
		cpu_topo = &cpu_topology[cpu];

		if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
			continue;

		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
		if (cpu != cpuid)
			cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);

		if (cpuid_topo->core_id != cpu_topo->core_id)
			continue;

		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
		if (cpu != cpuid)
			cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
	}
}

void store_cpu_topology(unsigned int cpuid)
{
	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
	u64 mpidr;

	if (cpuid_topo->cluster_id != -1)
		goto topology_populated;

	mpidr = read_cpuid_mpidr();

	/* Uniprocessor systems can rely on default topology values */
	if (mpidr & MPIDR_UP_BITMASK)
		return;

	/* Create cpu topology mapping based on MPIDR. */
	if (mpidr & MPIDR_MT_BITMASK) {
		/* Multiprocessor system : Multi-threads per core */
		cpuid_topo->thread_id  = MPIDR_AFFINITY_LEVEL(mpidr, 0);
		cpuid_topo->core_id    = MPIDR_AFFINITY_LEVEL(mpidr, 1);
		cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) |
					 MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8;
	} else {
		/* Multiprocessor system : Single-thread per core */
		cpuid_topo->thread_id  = -1;
		cpuid_topo->core_id    = MPIDR_AFFINITY_LEVEL(mpidr, 0);
		cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) |
					 MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 |
					 MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16;
	}

	pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n",
		 cpuid, cpuid_topo->cluster_id, cpuid_topo->core_id,
		 cpuid_topo->thread_id, mpidr);

topology_populated:
	update_siblings_masks(cpuid);
}

static void __init reset_cpu_topology(void)
{
	unsigned int cpu;

	for_each_possible_cpu(cpu) {
		struct cpu_topology *cpu_topo = &cpu_topology[cpu];

		cpu_topo->thread_id = -1;
		cpu_topo->core_id = 0;
		cpu_topo->cluster_id = -1;

		cpumask_clear(&cpu_topo->core_sibling);
		cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
		cpumask_clear(&cpu_topo->thread_sibling);
		cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
	}
}

void __init init_cpu_topology(void)
{
	reset_cpu_topology();

	/*
	 * Discard anything that was parsed if we hit an error so we
	 * don't use partial information.
	 */
	if (of_have_populated_dt() && parse_dt_topology())
		reset_cpu_topology();
}
Commit	Line	Data
f6e763b9 MB	1	/*
	2	* arch/arm64/kernel/topology.c
	3	*
	4	* Copyright (C) 2011,2013,2014 Linaro Limited.
	5	*
	6	* Based on the arm32 version written by Vincent Guittot in turn based on
	7	* arch/sh/kernel/topology.c
	8	*
	9	* This file is subject to the terms and conditions of the GNU General Public
	10	* License. See the file "COPYING" in the main directory of this archive
	11	* for more details.
	12	*/
	13
606f4226	14	#include <linux/acpi.h>
f6e763b9 MB	15	#include <linux/cpu.h>
	16	#include <linux/cpumask.h>
	17	#include <linux/init.h>
	18	#include <linux/percpu.h>
	19	#include <linux/node.h>
	20	#include <linux/nodemask.h>
ebdc9447	21	#include <linux/of.h>
f6e763b9	22	#include <linux/sched.h>
7202bde8	23	#include <linux/slab.h>
be8f185d	24	#include <linux/string.h>
7202bde8	25	#include <linux/cpufreq.h>
f6e763b9	26
be8f185d	27	#include <asm/cpu.h>
4e6f7084	28	#include <asm/cputype.h>
f6e763b9 MB	29	#include <asm/topology.h>
f6e763b9 MB	30
7202bde8	31	static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
be8f185d	32	static DEFINE_MUTEX(cpu_scale_mutex);
7202bde8 JL	33
	34	unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
	35	{
	36	return per_cpu(cpu_scale, cpu);
	37	}
	38
	39	static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
	40	{
	41	per_cpu(cpu_scale, cpu) = capacity;
	42	}
	43
be8f185d JL	44	#ifdef CONFIG_PROC_SYSCTL
	45	static ssize_t cpu_capacity_show(struct device *dev,
	46	struct device_attribute *attr,
	47	char *buf)
	48	{
	49	struct cpu *cpu = container_of(dev, struct cpu, dev);
	50
	51	return sprintf(buf, "%lu\n",
	52	arch_scale_cpu_capacity(NULL, cpu->dev.id));
	53	}
	54
	55	static ssize_t cpu_capacity_store(struct device *dev,
	56	struct device_attribute *attr,
	57	const char *buf,
	58	size_t count)
	59	{
	60	struct cpu *cpu = container_of(dev, struct cpu, dev);
	61	int this_cpu = cpu->dev.id, i;
	62	unsigned long new_capacity;
	63	ssize_t ret;
	64
	65	if (count) {
	66	ret = kstrtoul(buf, 0, &new_capacity);
	67	if (ret)
	68	return ret;
	69	if (new_capacity > SCHED_CAPACITY_SCALE)
	70	return -EINVAL;
	71
	72	mutex_lock(&cpu_scale_mutex);
	73	for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
	74	set_capacity_scale(i, new_capacity);
	75	mutex_unlock(&cpu_scale_mutex);
	76	}
	77
	78	return count;
	79	}
	80
	81	static DEVICE_ATTR_RW(cpu_capacity);
	82
	83	static int register_cpu_capacity_sysctl(void)
	84	{
	85	int i;
	86	struct device *cpu;
	87
	88	for_each_possible_cpu(i) {
	89	cpu = get_cpu_device(i);
	90	if (!cpu) {
	91	pr_err("%s: too early to get CPU%d device!\n",
	92	__func__, i);
	93	continue;
	94	}
	95	device_create_file(cpu, &dev_attr_cpu_capacity);
	96	}
	97
	98	return 0;
	99	}
	100	subsys_initcall(register_cpu_capacity_sysctl);
	101	#endif
	102
7202bde8 JL	103	static u32 capacity_scale;
	104	static u32 *raw_capacity;
	105	static bool cap_parsing_failed;
	106
	107	static void __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
	108	{
	109	int ret;
	110	u32 cpu_capacity;
	111
	112	if (cap_parsing_failed)
	113	return;
	114
	115	ret = of_property_read_u32(cpu_node,
	116	"capacity-dmips-mhz",
	117	&cpu_capacity);
	118	if (!ret) {
	119	if (!raw_capacity) {
	120	raw_capacity = kcalloc(num_possible_cpus(),
	121	sizeof(*raw_capacity),
	122	GFP_KERNEL);
	123	if (!raw_capacity) {
	124	pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
	125	cap_parsing_failed = true;
	126	return;
	127	}
	128	}
	129	capacity_scale = max(cpu_capacity, capacity_scale);
	130	raw_capacity[cpu] = cpu_capacity;
	131	pr_debug("cpu_capacity: %s cpu_capacity=%u (raw)\n",
	132	cpu_node->full_name, raw_capacity[cpu]);
	133	} else {
	134	if (raw_capacity) {
	135	pr_err("cpu_capacity: missing %s raw capacity\n",
	136	cpu_node->full_name);
	137	pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
	138	}
	139	cap_parsing_failed = true;
	140	kfree(raw_capacity);
	141	}
	142	}
	143
	144	static void normalize_cpu_capacity(void)
	145	{
	146	u64 capacity;
	147	int cpu;
	148
	149	if (!raw_capacity \|\| cap_parsing_failed)
	150	return;
	151
	152	pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
be8f185d	153	mutex_lock(&cpu_scale_mutex);
7202bde8 JL	154	for_each_possible_cpu(cpu) {
	155	pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
	156	cpu, raw_capacity[cpu]);
	157	capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
	158	/ capacity_scale;
	159	set_capacity_scale(cpu, capacity);
	160	pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
	161	cpu, arch_scale_cpu_capacity(NULL, cpu));
	162	}
be8f185d	163	mutex_unlock(&cpu_scale_mutex);
7202bde8 JL	164	}
	165
	166	#ifdef CONFIG_CPU_FREQ
	167	static cpumask_var_t cpus_to_visit;
	168	static bool cap_parsing_done;
	169	static void parsing_done_workfn(struct work_struct *work);
	170	static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
	171
	172	static int
	173	init_cpu_capacity_callback(struct notifier_block *nb,
	174	unsigned long val,
	175	void *data)
	176	{
	177	struct cpufreq_policy *policy = data;
	178	int cpu;
	179
	180	if (cap_parsing_failed \|\| cap_parsing_done)
	181	return 0;
	182
	183	switch (val) {
	184	case CPUFREQ_NOTIFY:
	185	pr_debug("cpu_capacity: init cpu capacity for CPUs [%pbl] (to_visit=%pbl)\n",
	186	cpumask_pr_args(policy->related_cpus),
	187	cpumask_pr_args(cpus_to_visit));
	188	cpumask_andnot(cpus_to_visit,
	189	cpus_to_visit,
	190	policy->related_cpus);
	191	for_each_cpu(cpu, policy->related_cpus) {
	192	raw_capacity[cpu] = arch_scale_cpu_capacity(NULL, cpu) *
	193	policy->cpuinfo.max_freq / 1000UL;
	194	capacity_scale = max(raw_capacity[cpu], capacity_scale);
	195	}
	196	if (cpumask_empty(cpus_to_visit)) {
	197	normalize_cpu_capacity();
	198	kfree(raw_capacity);
	199	pr_debug("cpu_capacity: parsing done\n");
	200	cap_parsing_done = true;
	201	schedule_work(&parsing_done_work);
	202	}
	203	}
	204	return 0;
	205	}
	206
	207	static struct notifier_block init_cpu_capacity_notifier = {
	208	.notifier_call = init_cpu_capacity_callback,
	209	};
	210
	211	static int __init register_cpufreq_notifier(void)
	212	{
606f4226 PP	213	/*
	214	* on ACPI-based systems we need to use the default cpu capacity
	215	* until we have the necessary code to parse the cpu capacity, so
	216	* skip registering cpufreq notifier.
	217	*/
	218	if (!acpi_disabled \|\| cap_parsing_failed)
7202bde8 JL	219	return -EINVAL;
	220
	221	if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
	222	pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
	223	return -ENOMEM;
	224	}
	225	cpumask_copy(cpus_to_visit, cpu_possible_mask);
	226
	227	return cpufreq_register_notifier(&init_cpu_capacity_notifier,
	228	CPUFREQ_POLICY_NOTIFIER);
	229	}
	230	core_initcall(register_cpufreq_notifier);
	231
	232	static void parsing_done_workfn(struct work_struct *work)
	233	{
	234	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
	235	CPUFREQ_POLICY_NOTIFIER);
	236	}
	237
	238	#else
	239	static int __init free_raw_capacity(void)
	240	{
	241	kfree(raw_capacity);
	242
	243	return 0;
	244	}
	245	core_initcall(free_raw_capacity);
	246	#endif
	247
ebdc9447 MB	248	static int __init get_cpu_for_node(struct device_node *node)
	249	{
	250	struct device_node *cpu_node;
	251	int cpu;
	252
	253	cpu_node = of_parse_phandle(node, "cpu", 0);
	254	if (!cpu_node)
	255	return -1;
	256
	257	for_each_possible_cpu(cpu) {
	258	if (of_get_cpu_node(cpu, NULL) == cpu_node) {
7202bde8	259	parse_cpu_capacity(cpu_node, cpu);
ebdc9447 MB	260	of_node_put(cpu_node);
	261	return cpu;
	262	}
	263	}
	264
	265	pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name);
	266
	267	of_node_put(cpu_node);
	268	return -1;
	269	}
	270
	271	static int __init parse_core(struct device_node *core, int cluster_id,
	272	int core_id)
	273	{
	274	char name[10];
	275	bool leaf = true;
	276	int i = 0;
	277	int cpu;
	278	struct device_node *t;
	279
	280	do {
	281	snprintf(name, sizeof(name), "thread%d", i);
	282	t = of_get_child_by_name(core, name);
	283	if (t) {
	284	leaf = false;
	285	cpu = get_cpu_for_node(t);
	286	if (cpu >= 0) {
	287	cpu_topology[cpu].cluster_id = cluster_id;
	288	cpu_topology[cpu].core_id = core_id;
	289	cpu_topology[cpu].thread_id = i;
	290	} else {
	291	pr_err("%s: Can't get CPU for thread\n",
	292	t->full_name);
	293	of_node_put(t);
	294	return -EINVAL;
	295	}
	296	of_node_put(t);
	297	}
	298	i++;
	299	} while (t);
	300
	301	cpu = get_cpu_for_node(core);
	302	if (cpu >= 0) {
	303	if (!leaf) {
	304	pr_err("%s: Core has both threads and CPU\n",
	305	core->full_name);
	306	return -EINVAL;
	307	}
	308
	309	cpu_topology[cpu].cluster_id = cluster_id;
	310	cpu_topology[cpu].core_id = core_id;
	311	} else if (leaf) {
	312	pr_err("%s: Can't get CPU for leaf core\n", core->full_name);
	313	return -EINVAL;
	314	}
	315
	316	return 0;
	317	}
	318
	319	static int __init parse_cluster(struct device_node *cluster, int depth)
	320	{
	321	char name[10];
	322	bool leaf = true;
	323	bool has_cores = false;
324	struct device_node *c;
325	static int cluster_id __initdata;
326	int core_id = 0;
327	int i, ret;
328
329	/*
330	* First check for child clusters; we currently ignore any
331	* information about the nesting of clusters and present the
332	* scheduler with a flat list of them.
333	*/
334	i = 0;
335	do {
336	snprintf(name, sizeof(name), "cluster%d", i);
337	c = of_get_child_by_name(cluster, name);
338	if (c) {
339	leaf = false;
340	ret = parse_cluster(c, depth + 1);
341	of_node_put(c);
342	if (ret != 0)
343	return ret;
344	}
345	i++;
346	} while (c);
347
348	/* Now check for cores */
349	i = 0;
350	do {
351	snprintf(name, sizeof(name), "core%d", i);
352	c = of_get_child_by_name(cluster, name);
353	if (c) {
354	has_cores = true;
355
356	if (depth == 0) {
357	pr_err("%s: cpu-map children should be clusters\n",
358	c->full_name);
359	of_node_put(c);
360	return -EINVAL;
361	}
362
363	if (leaf) {
364	ret = parse_core(c, cluster_id, core_id++);
365	} else {
366	pr_err("%s: Non-leaf cluster with core %s\n",
367	cluster->full_name, name);
368	ret = -EINVAL;
369	}
370
371	of_node_put(c);
372	if (ret != 0)
373	return ret;
374	}
375	i++;
376	} while (c);
377
378	if (leaf && !has_cores)
379	pr_warn("%s: empty cluster\n", cluster->full_name);
380
381	if (leaf)
382	cluster_id++;
383
384	return 0;
385	}
386
387	static int __init parse_dt_topology(void)
388	{
389	struct device_node cn, map;
390	int ret = 0;
391	int cpu;
392
393	cn = of_find_node_by_path("/cpus");
394	if (!cn) {
395	pr_err("No CPU information found in DT\n");
396	return 0;
397	}
398
399	/*
400	* When topology is provided cpu-map is essentially a root
401	* cluster with restricted subnodes.
402	*/
403	map = of_get_child_by_name(cn, "cpu-map");
7202bde8 JL	404	if (!map) {
7202bde8 JL	405	cap_parsing_failed = true;
ebdc9447	406	goto out;
7202bde8	407	}
ebdc9447 MB	408
	409	ret = parse_cluster(map, 0);
	410	if (ret != 0)
	411	goto out_map;
	412
7202bde8 JL	413	normalize_cpu_capacity();
7202bde8 JL	414
ebdc9447 MB	415	/*
	416	* Check that all cores are in the topology; the SMP code will
	417	* only mark cores described in the DT as possible.
	418	*/
4e6f7084 ZSL	419	for_each_possible_cpu(cpu)
4e6f7084 ZSL	420	if (cpu_topology[cpu].cluster_id == -1)
ebdc9447	421	ret = -EINVAL;
ebdc9447 MB	422
	423	out_map:
	424	of_node_put(map);
	425	out:
	426	of_node_put(cn);
	427	return ret;
	428	}
	429
f6e763b9 MB	430	/*
	431	* cpu topology table
	432	*/
	433	struct cpu_topology cpu_topology[NR_CPUS];
	434	EXPORT_SYMBOL_GPL(cpu_topology);
	435
	436	const struct cpumask *cpu_coregroup_mask(int cpu)
	437	{
	438	return &cpu_topology[cpu].core_sibling;
	439	}
	440
	441	static void update_siblings_masks(unsigned int cpuid)
	442	{
	443	struct cpu_topology cpu_topo, cpuid_topo = &cpu_topology[cpuid];
	444	int cpu;
	445
f6e763b9 MB	446	/* update core and thread sibling masks */
	447	for_each_possible_cpu(cpu) {
	448	cpu_topo = &cpu_topology[cpu];
	449
	450	if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
	451	continue;
	452
	453	cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
	454	if (cpu != cpuid)
	455	cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
	456
	457	if (cpuid_topo->core_id != cpu_topo->core_id)
	458	continue;
	459
	460	cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
	461	if (cpu != cpuid)
	462	cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
	463	}
	464	}
	465
	466	void store_cpu_topology(unsigned int cpuid)
	467	{
4e6f7084 ZSL	468	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
	469	u64 mpidr;
	470
	471	if (cpuid_topo->cluster_id != -1)
	472	goto topology_populated;
	473
	474	mpidr = read_cpuid_mpidr();
	475
	476	/* Uniprocessor systems can rely on default topology values */
	477	if (mpidr & MPIDR_UP_BITMASK)
	478	return;
	479
	480	/* Create cpu topology mapping based on MPIDR. */
	481	if (mpidr & MPIDR_MT_BITMASK) {
	482	/* Multiprocessor system : Multi-threads per core */
	483	cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
	484	cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
1cefdaea MB	485	cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) \|
1cefdaea MB	486	MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8;
4e6f7084 ZSL	487	} else {
	488	/* Multiprocessor system : Single-thread per core */
	489	cpuid_topo->thread_id = -1;
	490	cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
1cefdaea MB	491	cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) \|
	492	MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 \|
	493	MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16;
4e6f7084 ZSL	494	}
	495
	496	pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n",
	497	cpuid, cpuid_topo->cluster_id, cpuid_topo->core_id,
	498	cpuid_topo->thread_id, mpidr);
	499
	500	topology_populated:
f6e763b9 MB	501	update_siblings_masks(cpuid);
	502	}
	503
ebdc9447	504	static void __init reset_cpu_topology(void)
f6e763b9 MB	505	{
	506	unsigned int cpu;
	507
f6e763b9 MB	508	for_each_possible_cpu(cpu) {
	509	struct cpu_topology *cpu_topo = &cpu_topology[cpu];
	510
	511	cpu_topo->thread_id = -1;
c31bf048	512	cpu_topo->core_id = 0;
f6e763b9	513	cpu_topo->cluster_id = -1;
c31bf048	514
f6e763b9	515	cpumask_clear(&cpu_topo->core_sibling);
c31bf048	516	cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
f6e763b9	517	cpumask_clear(&cpu_topo->thread_sibling);
c31bf048	518	cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
f6e763b9 MB	519	}
f6e763b9 MB	520	}
ebdc9447 MB	521
	522	void __init init_cpu_topology(void)
	523	{
	524	reset_cpu_topology();
	525
	526	/*
	527	* Discard anything that was parsed if we hit an error so we
	528	* don't use partial information.
	529	*/
e094d445	530	if (of_have_populated_dt() && parse_dt_topology())
ebdc9447 MB	531	reset_cpu_topology();
ebdc9447 MB	532	}