Signed-off-by: Vincent Guittot <vincent.guit...@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();
}
--
1.7.4.1
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