Signed-off-by: Vincent Guittot vincent.guittot@linaro.org --- arch/arm/kernel/topology.c | 48 +++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 47 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 974177d..1196f2d 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -62,6 +62,41 @@ static void (*set_cpu_topology_mask)(void) = default_cpu_topology_mask; */ static DEFINE_PER_CPU(unsigned int, cpu_scale);

+ +struct cputopo_scale { + int scale; +}; + +static struct cputopo_scale cpu_power[NR_CPUS]; + +#define CPU_TOPO_MAX_SCALING 2 + +#define ARM_CORTEX_A9_DEFAULT_SCALE 0 +#define ARM_CORTEX_A9_POWER_SCALE 1 + +/* This table sets the cpu_power scale of a cpu according to the sched_mc mode. + * The content of this table could be SoC specific so we should add a method to + * overwrite this default table. + * TODO: Study how to use DT for setting this table + */ +static unsigned long table_cpu_power[CPU_TOPO_MAX_SCALING] = { + {1024}, /* default */ + {4096}, /* Power save mode CA9 MP */ +}; + +static void set_power_scale(unsigned int cpuid, unsigned int idx) +{ + cpu_power[cpuid].scale = idx; + per_cpu(cpu_scale, cpuid) = table_cpu_power[cpu_power[cpuid].scale]; + smp_wmb(); +} + +static int topo_cpuscale_init(void) +{ + /* Nothing to do right now */ + return 0; +} + /* * Update the cpu power */ @@ -123,6 +158,8 @@ static void default_cpu_topology_mask(void) } } } + + set_power_scale(cpuid, ARM_CORTEX_A9_DEFAULT_SCALE); } smp_wmb(); } @@ -133,8 +170,12 @@ static void default_cpu_topology_mask(void) */ static void power_cpu_topology_mask_CA9(void) { + unsigned int cpuid, cpu, idx;

- unsigned int cpuid, cpu; + if (num_possible_cpus() > 2) + idx = ARM_CORTEX_A9_DEFAULT_SCALE; + else + idx = ARM_CORTEX_A9_POWER_SCALE;

for_each_possible_cpu(cpuid) { struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid]; @@ -158,6 +199,8 @@ static void power_cpu_topology_mask_CA9(void) } } } + + set_power_scale(cpuid, idx); } smp_wmb(); } @@ -194,6 +237,7 @@ static int update_cpu_topology_policy(void)

return 0; } + /* * store_cpu_topology is called at boot when only one cpu is running * and with the mutex cpu_hotplug.lock locked, when several cpus have booted, @@ -293,6 +337,8 @@ void init_cpu_topology(void) cpumask_clear(&cpu_topo->thread_sibling);

per_cpu(cpu_scale, cpu) = SCHED_POWER_SCALE; + + cpu_power[cpu].scale = ARM_CORTEX_A9_DEFAULT_SCALE; } smp_wmb(); }