1 files changed, 107 insertions, 21 deletions

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index c47f3d09c1e..ed28f774ca4 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 +123,8 @@ struct menu_device {
 	int		interval_ptr;
 };
 
+static int tune_multiplier = 1024;
+static int forced_state;
 
 #define LOAD_INT(x) ((x) >> FSHIFT)
 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
@@ -170,6 +174,9 @@ 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 +184,9 @@ 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;
 }
 
@@ -281,26 +291,34 @@ static int menu_select(struct cpuidle_device *dev)
 	if (data->expected_us > 5)
 		data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
 
-	/*
-	 * Find the idle state with the lowest power while satisfying
-	 * our constraints.
-	 */
-	for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++) {
-		struct cpuidle_state *s = &dev->states[i];
-
-		if (s->flags & CPUIDLE_FLAG_IGNORE)
-			continue;
-		if (s->target_residency > data->predicted_us)
-			continue;
-		if (s->exit_latency > latency_req)
-			continue;
-		if (s->exit_latency * multiplier > data->predicted_us)
-			continue;
-
-		if (s->power_usage < power_usage) {
-			power_usage = s->power_usage;
-			data->last_state_idx = i;
-			data->exit_us = s->exit_latency;
+	WARN((forced_state >= dev->state_count), \
+		"Forced state value out of range.\n");
+
+	if ((forced_state != 0) && (forced_state < dev->state_count)) {
+		data->exit_us = dev->states[forced_state].exit_latency;
+		data->last_state_idx = forced_state;
+	} else {
+		/*
+		 * Find the idle state with the lowest power while satisfying
+		 * our constraints.
+		 */
+		for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++) {
+			struct cpuidle_state *s = &dev->states[i];
+
+			if (s->flags & CPUIDLE_FLAG_IGNORE)
+				continue;
+			if (s->target_residency > data->predicted_us)
+				continue;
+			if (s->exit_latency > latency_req)
+				continue;
+			if (s->exit_latency * multiplier > data->predicted_us)
+				continue;
+
+			if (s->power_usage < power_usage) {
+				power_usage = s->power_usage;
+				data->last_state_idx = i;
+				data->exit_us = s->exit_latency;
+			}
 		}
 	}
 
@@ -381,6 +399,63 @@ 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);
+
+/* Writing 0 will remove the forced state. */
+int cpuidle_force_state(unsigned int state)
+{
+	forced_state = state;
+
+	return 0;
+}
+EXPORT_SYMBOL(cpuidle_force_state);
+
+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
@@ -408,7 +483,15 @@ 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;
+
 }
 
 /**
@@ -416,6 +499,9 @@ 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);
 }