diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 598323a1842e..e683d147816c 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -190,6 +190,13 @@ static int __init parse_cluster(struct device_node *cluster, int depth) return 0; } +static DEFINE_PER_CPU(unsigned long, cpu_efficiency) = SCHED_CAPACITY_SCALE; + +unsigned long arch_get_cpu_efficiency(int cpu) +{ + return per_cpu(cpu_efficiency, cpu); +} + #ifdef CONFIG_OF struct cpu_efficiency { const char *compatible; @@ -266,6 +273,7 @@ static int __init parse_dt_topology(void) for_each_possible_cpu(cpu) { const u32 *rate; int len; + u32 efficiency; /* too early to use cpu->of_node */ cn = of_get_cpu_node(cpu, NULL); @@ -274,12 +282,26 @@ static int __init parse_dt_topology(void) continue; } - for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++) - if (of_device_is_compatible(cn, cpu_eff->compatible)) - break; + /* + * The CPU efficiency value passed from the device tree + * overrides the value defined in the table_efficiency[] + */ + if (of_property_read_u32(cn, "efficiency", &efficiency) < 0) { - if (cpu_eff->compatible == NULL) - continue; + for (cpu_eff = table_efficiency; + cpu_eff->compatible; cpu_eff++) + + if (of_device_is_compatible(cn, + cpu_eff->compatible)) + break; + + if (cpu_eff->compatible == NULL) + continue; + + efficiency = cpu_eff->efficiency; + } + + per_cpu(cpu_efficiency, cpu) = efficiency; rate = of_get_property(cn, "clock-frequency", &len); if (!rate || len != 4) { @@ -288,7 +310,7 @@ static int __init parse_dt_topology(void) continue; } - capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency; + capacity = ((be32_to_cpup(rate)) >> 20) * efficiency; /* Save min capacity of the system */ if (capacity < min_capacity)