From 130d9aabf997bd8449ff4e877fe3c42df066805e Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Tue, 10 Jul 2012 14:08:40 +0100 Subject: ARM: 7461/1: topology: Add arch_scale_freq_power function Add infrastructure to be able to modify the cpu_power of each core Signed-off-by: Vincent Guittot Reviewed-by: Namhyung Kim Acked-by: Peter Zijlstra Signed-off-by: Russell King --- arch/arm/kernel/topology.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 8200dea..51f23b3 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -22,6 +22,37 @@ #include #include +/* + * cpu power scale management + */ + +/* + * cpu power table + * This per cpu data structure describes the relative capacity of each core. + * On a heteregenous system, cores don't have the same computation capacity + * and we reflect that difference in the cpu_power field so the scheduler can + * take this difference into account during load balance. A per cpu structure + * is preferred because each CPU updates its own cpu_power field during the + * load balance except for idle cores. One idle core is selected to run the + * rebalance_domains for all idle cores and the cpu_power can be updated + * during this sequence. + */ +static DEFINE_PER_CPU(unsigned long, cpu_scale); + +unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu) +{ + return per_cpu(cpu_scale, cpu); +} + +static void set_power_scale(unsigned int cpu, unsigned long power) +{ + per_cpu(cpu_scale, cpu) = power; +} + +/* + * cpu topology management + */ + #define MPIDR_SMP_BITMASK (0x3 << 30) #define MPIDR_SMP_VALUE (0x2 << 30) @@ -41,6 +72,9 @@ #define MPIDR_LEVEL2_MASK 0xFF #define MPIDR_LEVEL2_SHIFT 16 +/* + * cpu topology table + */ struct cputopo_arm cpu_topology[NR_CPUS]; const struct cpumask *cpu_coregroup_mask(int cpu) @@ -134,7 +168,7 @@ void init_cpu_topology(void) { unsigned int cpu; - /* init core mask */ + /* init core mask and power*/ for_each_possible_cpu(cpu) { struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]); @@ -143,6 +177,8 @@ void init_cpu_topology(void) cpu_topo->socket_id = -1; cpumask_clear(&cpu_topo->core_sibling); cpumask_clear(&cpu_topo->thread_sibling); + + set_power_scale(cpu, SCHED_POWER_SCALE); } smp_wmb(); } -- cgit v1.1