[RFC PATCH v2 05/09] ARM: cpu topology: Modify cpu_power according to sched_mc level

Vincent Guittot vincent.guittot at linaro.org
Mon Nov 14 12:38:57 UTC 2011


Signed-off-by: Vincent Guittot <vincent.guittot at linaro.org>
---
 arch/arm/kernel/topology.c |   43 +++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 9d80e22..2774c5d 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -19,6 +19,7 @@
 #include <linux/nodemask.h>
 #include <linux/sched.h>
 #include <linux/cpumask.h>
+#include <linux/cpuset.h>
 
 #include <asm/cputype.h>
 #include <asm/topology.h>
@@ -61,6 +62,43 @@ static DEFINE_PER_CPU(unsigned int, cpu_scale);
 
 unsigned int advanced_topology = 1;
 
+static void normal_cpu_topology_mask(void);
+static void (*set_cpu_topology_mask)(void) = normal_cpu_topology_mask;
+
+/* 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
+ */
+#define ARM_CORTEX_A9_DEFAULT_SCALE 0
+#define ARM_CORTEX_A9_POWER_SCALE 1
+/* This table list all possible cpu power configuration */
+unsigned int table_config[2] = {
+	1024,
+	4096
+};
+
+static void set_power_scale(unsigned int cpu, unsigned int idx)
+{
+	per_cpu(cpu_scale, cpu) = table_config[idx];
+}
+
+static int init_cpu_power_scale(void)
+{
+	/* Do we need to change default config */
+	advanced_topology = 1;
+
+	/* force topology update */
+	arch_update_cpu_topology();
+
+	/* Force a cpu topology update */
+	rebuild_sched_domains();
+
+	return 0;
+}
+
+core_initcall(init_cpu_power_scale);
+
 /*
  * Update the cpu power
  */
@@ -129,6 +167,7 @@ static void normal_cpu_topology_mask(void)
 
 	for_each_possible_cpu(cpuid) {
 		default_cpu_topology_mask(cpuid);
+		set_power_scale(cpuid, ARM_CORTEX_A9_DEFAULT_SCALE);
 	}
 	smp_wmb();
 }
@@ -139,7 +178,6 @@ static void normal_cpu_topology_mask(void)
  */
 static void power_cpu_topology_mask_CA9(void)
 {
-
 	unsigned int cpuid, cpu;
 
 	for_each_possible_cpu(cpuid) {
@@ -164,6 +202,7 @@ static void power_cpu_topology_mask_CA9(void)
 				}
 			}
 		}
+		set_power_scale(cpuid, ARM_CORTEX_A9_POWER_SCALE);
 	}
 	smp_wmb();
 }
@@ -278,7 +317,7 @@ int arch_update_cpu_topology(void)
 	/* set topology policy */
 	update_cpu_topology_policy();
 
-	/* set topology mask*/
+	/* set topology mask and power */
 	(*set_cpu_topology_mask)();
 
 	return 1;
-- 
1.7.4.1




More information about the linaro-dev mailing list