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authorMark Hambleton <mahamble@broadcom.com>2013-11-27 13:30:29 +0000
committerMark Brown <broonie@linaro.org>2013-12-13 13:23:36 +0000
commit8ecd48091c61213762407f5ce02d3fa4ede66402 (patch)
tree3884f06961d61a1f895881c13d97205ce414c0a9 /arch/arm64/kernel/topology.c
parentd474d10a1a827e0b3402943a62a97d95c0eabf8d (diff)
downloadlinaro-lsk-v3.10/topic/arm64-hmp.tar.gz
arm64: Enable HMP for ARMv8v3.10/topic/arm64-hmp
Signed-off-by: Mark Hambleton <mahamble@broadcom.com> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'arch/arm64/kernel/topology.c')
-rw-r--r--arch/arm64/kernel/topology.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 83d6919d4e0..971064a0c6b 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -363,6 +363,125 @@ void store_cpu_topology(unsigned int cpuid)
update_cpu_power(cpuid);
}
+#ifdef CONFIG_SCHED_HMP
+
+/*
+ * Retrieve logical cpu index corresponding to a given MPIDR[23:0]
+ * - mpidr: MPIDR[23:0] to be used for the look-up
+ *
+ * Returns the cpu logical index or -EINVAL on look-up error
+ */
+static inline int get_logical_index(u32 mpidr)
+{
+ int cpu;
+ for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+ if (cpu_logical_map(cpu) == mpidr)
+ return cpu;
+ return -EINVAL;
+}
+
+static const char * const little_cores[] = {
+ "arm,cortex-a53",
+ NULL,
+};
+
+static bool is_little_cpu(struct device_node *cn)
+{
+ const char * const *lc;
+ for (lc = little_cores; *lc; lc++)
+ if (of_device_is_compatible(cn, *lc))
+ return true;
+ return false;
+}
+
+void __init arch_get_fast_and_slow_cpus(struct cpumask *fast,
+ struct cpumask *slow)
+{
+ struct device_node *cn = NULL;
+ int cpu;
+
+ cpumask_clear(fast);
+ cpumask_clear(slow);
+
+ /*
+ * Use the config options if they are given. This helps testing
+ * HMP scheduling on systems without a big.LITTLE architecture.
+ */
+ if (strlen(CONFIG_HMP_FAST_CPU_MASK) && strlen(CONFIG_HMP_SLOW_CPU_MASK)) {
+ if (cpulist_parse(CONFIG_HMP_FAST_CPU_MASK, fast))
+ WARN(1, "Failed to parse HMP fast cpu mask!\n");
+ if (cpulist_parse(CONFIG_HMP_SLOW_CPU_MASK, slow))
+ WARN(1, "Failed to parse HMP slow cpu mask!\n");
+ return;
+ }
+
+ /*
+ * Else, parse device tree for little cores.
+ */
+ while ((cn = of_find_node_by_type(cn, "cpu"))) {
+
+ const u32 *mpidr;
+ int len;
+
+ mpidr = of_get_property(cn, "reg", &len);
+ if (!mpidr || len != 8) {
+ pr_err("%s missing reg property\n", cn->full_name);
+ continue;
+ }
+
+ cpu = get_logical_index(be32_to_cpup(mpidr+1));
+ if (cpu == -EINVAL) {
+ pr_err("couldn't get logical index for mpidr %x\n",
+ be32_to_cpup(mpidr+1));
+ break;
+ }
+
+ if (is_little_cpu(cn))
+ cpumask_set_cpu(cpu, slow);
+ else
+ cpumask_set_cpu(cpu, fast);
+ }
+
+ if (!cpumask_empty(fast) && !cpumask_empty(slow))
+ return;
+
+ /*
+ * We didn't find both big and little cores so let's call all cores
+ * fast as this will keep the system running, with all cores being
+ * treated equal.
+ */
+ cpumask_setall(fast);
+ cpumask_clear(slow);
+}
+
+struct cpumask hmp_slow_cpu_mask;
+
+void __init arch_get_hmp_domains(struct list_head *hmp_domains_list)
+{
+ struct cpumask hmp_fast_cpu_mask;
+ struct hmp_domain *domain;
+
+ arch_get_fast_and_slow_cpus(&hmp_fast_cpu_mask, &hmp_slow_cpu_mask);
+
+ /*
+ * Initialize hmp_domains
+ * Must be ordered with respect to compute capacity.
+ * Fastest domain at head of list.
+ */
+ if(!cpumask_empty(&hmp_slow_cpu_mask)) {
+ domain = (struct hmp_domain *)
+ kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
+ cpumask_copy(&domain->possible_cpus, &hmp_slow_cpu_mask);
+ cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
+ list_add(&domain->hmp_domains, hmp_domains_list);
+ }
+ domain = (struct hmp_domain *)
+ kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
+ cpumask_copy(&domain->possible_cpus, &hmp_fast_cpu_mask);
+ cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
+ list_add(&domain->hmp_domains, hmp_domains_list);
+}
+#endif /* CONFIG_SCHED_HMP */
/*
* cluster_to_logical_mask - return cpu logical mask of CPUs in a cluster