[linux-2.6-block.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/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 <asm/cputype.h>
#include <asm/topology.h>

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) {
			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)
		goto out;

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

	/*
	 * 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
	14	#include <linux/cpu.h>
	15	#include <linux/cpumask.h>
	16	#include <linux/init.h>
	17	#include <linux/percpu.h>
	18	#include <linux/node.h>
	19	#include <linux/nodemask.h>
ebdc9447	20	#include <linux/of.h>
f6e763b9 MB	21	#include <linux/sched.h>
f6e763b9 MB	22
4e6f7084	23	#include <asm/cputype.h>
f6e763b9 MB	24	#include <asm/topology.h>
f6e763b9 MB	25
ebdc9447 MB	26	static int __init get_cpu_for_node(struct device_node *node)
	27	{
	28	struct device_node *cpu_node;
	29	int cpu;
	30
	31	cpu_node = of_parse_phandle(node, "cpu", 0);
	32	if (!cpu_node)
	33	return -1;
	34
	35	for_each_possible_cpu(cpu) {
	36	if (of_get_cpu_node(cpu, NULL) == cpu_node) {
	37	of_node_put(cpu_node);
	38	return cpu;
	39	}
	40	}
	41
	42	pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name);
	43
	44	of_node_put(cpu_node);
	45	return -1;
	46	}
	47
	48	static int __init parse_core(struct device_node *core, int cluster_id,
	49	int core_id)
	50	{
	51	char name[10];
	52	bool leaf = true;
	53	int i = 0;
	54	int cpu;
	55	struct device_node *t;
	56
	57	do {
	58	snprintf(name, sizeof(name), "thread%d", i);
	59	t = of_get_child_by_name(core, name);
	60	if (t) {
	61	leaf = false;
	62	cpu = get_cpu_for_node(t);
	63	if (cpu >= 0) {
	64	cpu_topology[cpu].cluster_id = cluster_id;
	65	cpu_topology[cpu].core_id = core_id;
	66	cpu_topology[cpu].thread_id = i;
	67	} else {
	68	pr_err("%s: Can't get CPU for thread\n",
	69	t->full_name);
	70	of_node_put(t);
	71	return -EINVAL;
	72	}
	73	of_node_put(t);
	74	}
	75	i++;
	76	} while (t);
	77
	78	cpu = get_cpu_for_node(core);
	79	if (cpu >= 0) {
	80	if (!leaf) {
	81	pr_err("%s: Core has both threads and CPU\n",
	82	core->full_name);
	83	return -EINVAL;
	84	}
	85
	86	cpu_topology[cpu].cluster_id = cluster_id;
	87	cpu_topology[cpu].core_id = core_id;
	88	} else if (leaf) {
	89	pr_err("%s: Can't get CPU for leaf core\n", core->full_name);
90	return -EINVAL;
91	}
92
93	return 0;
94	}
95
96	static int __init parse_cluster(struct device_node *cluster, int depth)
97	{
98	char name[10];
99	bool leaf = true;
100	bool has_cores = false;
101	struct device_node *c;
102	static int cluster_id __initdata;
103	int core_id = 0;
104	int i, ret;
105
106	/*
107	* First check for child clusters; we currently ignore any
108	* information about the nesting of clusters and present the
109	* scheduler with a flat list of them.
110	*/
111	i = 0;
112	do {
113	snprintf(name, sizeof(name), "cluster%d", i);
114	c = of_get_child_by_name(cluster, name);
115	if (c) {
116	leaf = false;
117	ret = parse_cluster(c, depth + 1);
118	of_node_put(c);
119	if (ret != 0)
120	return ret;
121	}
122	i++;
123	} while (c);
124
125	/* Now check for cores */
126	i = 0;
127	do {
128	snprintf(name, sizeof(name), "core%d", i);
129	c = of_get_child_by_name(cluster, name);
130	if (c) {
131	has_cores = true;
132
133	if (depth == 0) {
134	pr_err("%s: cpu-map children should be clusters\n",
135	c->full_name);
136	of_node_put(c);
137	return -EINVAL;
138	}
139
140	if (leaf) {
141	ret = parse_core(c, cluster_id, core_id++);
142	} else {
143	pr_err("%s: Non-leaf cluster with core %s\n",
144	cluster->full_name, name);
145	ret = -EINVAL;
146	}
147
148	of_node_put(c);
149	if (ret != 0)
150	return ret;
151	}
152	i++;
153	} while (c);
154
155	if (leaf && !has_cores)
156	pr_warn("%s: empty cluster\n", cluster->full_name);
157
158	if (leaf)
159	cluster_id++;
160
161	return 0;
162	}
163
164	static int __init parse_dt_topology(void)
165	{
166	struct device_node cn, map;
167	int ret = 0;
168	int cpu;
169
170	cn = of_find_node_by_path("/cpus");
171	if (!cn) {
172	pr_err("No CPU information found in DT\n");
173	return 0;
174	}
175
176	/*
177	* When topology is provided cpu-map is essentially a root
178	* cluster with restricted subnodes.
179	*/
180	map = of_get_child_by_name(cn, "cpu-map");
181	if (!map)
182	goto out;
183
184	ret = parse_cluster(map, 0);
185	if (ret != 0)
186	goto out_map;
187
188	/*
189	* Check that all cores are in the topology; the SMP code will
190	* only mark cores described in the DT as possible.
191	*/
4e6f7084 ZSL	192	for_each_possible_cpu(cpu)
4e6f7084 ZSL	193	if (cpu_topology[cpu].cluster_id == -1)
ebdc9447	194	ret = -EINVAL;
ebdc9447 MB	195
	196	out_map:
	197	of_node_put(map);
	198	out:
	199	of_node_put(cn);
	200	return ret;
	201	}
	202
f6e763b9 MB	203	/*
	204	* cpu topology table
	205	*/
	206	struct cpu_topology cpu_topology[NR_CPUS];
	207	EXPORT_SYMBOL_GPL(cpu_topology);
	208
	209	const struct cpumask *cpu_coregroup_mask(int cpu)
	210	{
	211	return &cpu_topology[cpu].core_sibling;
	212	}
	213
	214	static void update_siblings_masks(unsigned int cpuid)
	215	{
	216	struct cpu_topology cpu_topo, cpuid_topo = &cpu_topology[cpuid];
	217	int cpu;
	218
f6e763b9 MB	219	/* update core and thread sibling masks */
	220	for_each_possible_cpu(cpu) {
	221	cpu_topo = &cpu_topology[cpu];
	222
	223	if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
	224	continue;
	225
	226	cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
	227	if (cpu != cpuid)
	228	cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
	229
	230	if (cpuid_topo->core_id != cpu_topo->core_id)
	231	continue;
	232
	233	cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
	234	if (cpu != cpuid)
	235	cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
	236	}
	237	}
	238
	239	void store_cpu_topology(unsigned int cpuid)
	240	{
4e6f7084 ZSL	241	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
	242	u64 mpidr;
	243
	244	if (cpuid_topo->cluster_id != -1)
	245	goto topology_populated;
	246
	247	mpidr = read_cpuid_mpidr();
	248
	249	/* Uniprocessor systems can rely on default topology values */
	250	if (mpidr & MPIDR_UP_BITMASK)
	251	return;
	252
	253	/* Create cpu topology mapping based on MPIDR. */
	254	if (mpidr & MPIDR_MT_BITMASK) {
	255	/* Multiprocessor system : Multi-threads per core */
	256	cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
	257	cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
1cefdaea MB	258	cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) \|
1cefdaea MB	259	MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8;
4e6f7084 ZSL	260	} else {
	261	/* Multiprocessor system : Single-thread per core */
	262	cpuid_topo->thread_id = -1;
	263	cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
1cefdaea MB	264	cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) \|
	265	MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 \|
	266	MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16;
4e6f7084 ZSL	267	}
	268
	269	pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n",
	270	cpuid, cpuid_topo->cluster_id, cpuid_topo->core_id,
	271	cpuid_topo->thread_id, mpidr);
	272
	273	topology_populated:
f6e763b9 MB	274	update_siblings_masks(cpuid);
	275	}
	276
ebdc9447	277	static void __init reset_cpu_topology(void)
f6e763b9 MB	278	{
	279	unsigned int cpu;
	280
f6e763b9 MB	281	for_each_possible_cpu(cpu) {
	282	struct cpu_topology *cpu_topo = &cpu_topology[cpu];
	283
	284	cpu_topo->thread_id = -1;
c31bf048	285	cpu_topo->core_id = 0;
f6e763b9	286	cpu_topo->cluster_id = -1;
c31bf048	287
f6e763b9	288	cpumask_clear(&cpu_topo->core_sibling);
c31bf048	289	cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
f6e763b9	290	cpumask_clear(&cpu_topo->thread_sibling);
c31bf048	291	cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
f6e763b9 MB	292	}
f6e763b9 MB	293	}
ebdc9447 MB	294
	295	void __init init_cpu_topology(void)
	296	{
	297	reset_cpu_topology();
	298
	299	/*
	300	* Discard anything that was parsed if we hit an error so we
	301	* don't use partial information.
	302	*/
e094d445	303	if (of_have_populated_dt() && parse_dt_topology())
ebdc9447 MB	304	reset_cpu_topology();
ebdc9447 MB	305	}