cpuidle: add interface for modifying multiplier

ST-Ericsson ID: 337167

Change-Id: I26ef492fd200960b40638c8a5a1f706ee24705bb
Signed-off-by: Vincent Guittot <vincent.guittot@stericsson.com>
Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/21971
Reviewed-by: QATEST
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>

1 files changed, 69 insertions, 1 deletions

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index f508690eb95..f9c6ca7b937 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -19,6 +19,8 @@
 #include <linux/tick.h>
 #include <linux/sched.h>
 #include <linux/math64.h>
+#include <linux/cpu.h>
+#include <linux/sysfs.h>
 
 #define BUCKETS 12
 #define INTERVALS 8
@@ -121,6 +123,7 @@ struct menu_device {
 	int		interval_ptr;
 };
 
+static int tune_multiplier = 1024;
 
 #define LOAD_INT(x) ((x) >> FSHIFT)
 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
@@ -170,6 +173,9 @@ static inline int performance_multiplier(void)
 {
 	int mult = 1;
 
+	if (tune_multiplier <= 1)
+		return tune_multiplier;
+
 	/* for higher loadavg, we are more reluctant */
 
 	mult += 2 * get_loadavg();
@@ -177,6 +183,9 @@ static inline int performance_multiplier(void)
 	/* for IO wait tasks (per cpu!) we add 5x each */
 	mult += 10 * nr_iowait_cpu(smp_processor_id());
 
+	if (tune_multiplier != 1024)
+		mult = (tune_multiplier * mult) / 1024;
+
 	return mult;
 }
 
@@ -379,6 +388,54 @@ static void menu_update(struct cpuidle_device *dev)
 		data->interval_ptr = 0;
 }
 
+int cpuidle_set_multiplier(unsigned int value)
+{
+
+	if (value > 1024)
+		tune_multiplier = 1024;
+	else
+		tune_multiplier = value;
+
+	return 0;
+}
+EXPORT_SYMBOL(cpuidle_set_multiplier);
+
+static ssize_t show_multiplier(struct sysdev_class *class,
+				      struct sysdev_class_attribute *attr,
+					  char *buf)
+{
+	return sprintf(buf, "%d\n", tune_multiplier);
+}
+
+static ssize_t store_multiplier(struct sysdev_class *class,
+					struct sysdev_class_attribute *attr,
+				    const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+	ret = sscanf(buf, "%u", &input);
+
+	if (ret != 1)
+		return -EINVAL;
+
+	cpuidle_set_multiplier(input);
+
+	return count;
+}
+
+
+static SYSDEV_CLASS_ATTR(multiplier, 0644, show_multiplier, store_multiplier);
+
+static struct attribute *dbs_attributes[] = {
+	&attr_multiplier.attr,
+	NULL
+};
+
+static struct attribute_group dbs_attr_group = {
+	.attrs = dbs_attributes,
+	.name = "cpuidle",
+};
+
 /**
  * menu_enable_device - scans a CPU's states and does setup
  * @dev: the CPU
@@ -406,7 +463,15 @@ static struct cpuidle_governor menu_governor = {
  */
 static int __init init_menu(void)
 {
-	return cpuidle_register_governor(&menu_governor);
+	int ret;
+
+	ret = cpuidle_register_governor(&menu_governor);
+
+	sysfs_merge_group(&(cpu_sysdev_class.kset.kobj),
+						&dbs_attr_group);
+
+	return ret;
+
 }
 
 /**
@@ -414,6 +479,9 @@ static int __init init_menu(void)
  */
 static void __exit exit_menu(void)
 {
+	sysfs_unmerge_group(&(cpu_sysdev_class.kset.kobj),
+						&dbs_attr_group);
+
 	cpuidle_unregister_governor(&menu_governor);
 }