linux/arch/arm64/kernel/topology.c

408 lines
9.2 KiB
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/arch_topology.h>
#include <linux/cacheinfo.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/sched/topology.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <asm/cpu.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;
cpu = of_cpu_node_to_id(cpu_node);
if (cpu >= 0)
topology_parse_cpu_capacity(cpu_node, cpu);
else
pr_crit("Unable to find CPU node for %pOF\n", cpu_node);
of_node_put(cpu_node);
return cpu;
}
static int __init parse_core(struct device_node *core, int package_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].package_id = package_id;
cpu_topology[cpu].core_id = core_id;
cpu_topology[cpu].thread_id = i;
} else {
pr_err("%pOF: Can't get CPU for thread\n",
t);
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("%pOF: Core has both threads and CPU\n",
core);
return -EINVAL;
}
cpu_topology[cpu].package_id = package_id;
cpu_topology[cpu].core_id = core_id;
} else if (leaf) {
pr_err("%pOF: Can't get CPU for leaf core\n", core);
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 package_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("%pOF: cpu-map children should be clusters\n",
c);
of_node_put(c);
return -EINVAL;
}
if (leaf) {
ret = parse_core(c, package_id, core_id++);
} else {
pr_err("%pOF: Non-leaf cluster with core %s\n",
cluster, name);
ret = -EINVAL;
}
of_node_put(c);
if (ret != 0)
return ret;
}
i++;
} while (c);
if (leaf && !has_cores)
pr_warn("%pOF: empty cluster\n", cluster);
if (leaf)
package_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;
topology_normalize_cpu_scale();
/*
* 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].package_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)
{
const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
/* Find the smaller of NUMA, core or LLC siblings */
if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
/* not numa in package, lets use the package siblings */
core_mask = &cpu_topology[cpu].core_sibling;
}
if (cpu_topology[cpu].llc_id != -1) {
if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
core_mask = &cpu_topology[cpu].llc_sibling;
}
return core_mask;
}
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_online_cpu(cpu) {
cpu_topo = &cpu_topology[cpu];
if (cpuid_topo->llc_id == cpu_topo->llc_id) {
cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
}
if (cpuid_topo->package_id != cpu_topo->package_id)
continue;
cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
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);
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->package_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->package_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->package_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->package_id, cpuid_topo->core_id,
cpuid_topo->thread_id, mpidr);
topology_populated:
update_siblings_masks(cpuid);
}
static void clear_cpu_topology(int cpu)
{
struct cpu_topology *cpu_topo = &cpu_topology[cpu];
cpumask_clear(&cpu_topo->llc_sibling);
cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
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);
}
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->package_id = -1;
cpu_topo->llc_id = -1;
clear_cpu_topology(cpu);
}
}
void remove_cpu_topology(unsigned int cpu)
{
int sibling;
for_each_cpu(sibling, topology_core_cpumask(cpu))
cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
for_each_cpu(sibling, topology_sibling_cpumask(cpu))
cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
for_each_cpu(sibling, topology_llc_cpumask(cpu))
cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
clear_cpu_topology(cpu);
}
#ifdef CONFIG_ACPI
/*
* Propagate the topology information of the processor_topology_node tree to the
* cpu_topology array.
*/
static int __init parse_acpi_topology(void)
{
bool is_threaded;
int cpu, topology_id;
is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK;
for_each_possible_cpu(cpu) {
int i, cache_id;
topology_id = find_acpi_cpu_topology(cpu, 0);
if (topology_id < 0)
return topology_id;
if (is_threaded) {
cpu_topology[cpu].thread_id = topology_id;
topology_id = find_acpi_cpu_topology(cpu, 1);
cpu_topology[cpu].core_id = topology_id;
} else {
cpu_topology[cpu].thread_id = -1;
cpu_topology[cpu].core_id = topology_id;
}
topology_id = find_acpi_cpu_topology_package(cpu);
cpu_topology[cpu].package_id = topology_id;
i = acpi_find_last_cache_level(cpu);
if (i > 0) {
/*
* this is the only part of cpu_topology that has
* a direct relationship with the cache topology
*/
cache_id = find_acpi_cpu_cache_topology(cpu, i);
if (cache_id > 0)
cpu_topology[cpu].llc_id = cache_id;
}
}
return 0;
}
#else
static inline int __init parse_acpi_topology(void)
{
return -EINVAL;
}
#endif
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 (!acpi_disabled && parse_acpi_topology())
reset_cpu_topology();
else if (of_have_populated_dt() && parse_dt_topology())
reset_cpu_topology();
}