1 files changed, 123 insertions, 0 deletions

diff --git a/kernel/drivers/cpufreq/cpufreq_userspace.c b/kernel/drivers/cpufreq/cpufreq_userspace.c
new file mode 100644
index 000000000..4dbf1db16
--- /dev/null
+++ b/kernel/drivers/cpufreq/cpufreq_userspace.c
@@ -0,0 +1,123 @@
+
+/*
+ *  linux/drivers/cpufreq/cpufreq_userspace.c
+ *
+ *  Copyright (C)  2001 Russell King
+ *            (C)  2002 - 2004 Dominik Brodowski <linux@brodo.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpufreq.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
+static DEFINE_MUTEX(userspace_mutex);
+
+/**
+ * cpufreq_set - set the CPU frequency
+ * @policy: pointer to policy struct where freq is being set
+ * @freq: target frequency in kHz
+ *
+ * Sets the CPU frequency to freq.
+ */
+static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
+{
+	int ret = -EINVAL;
+
+	pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
+
+	mutex_lock(&userspace_mutex);
+	if (!per_cpu(cpu_is_managed, policy->cpu))
+		goto err;
+
+	ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
+ err:
+	mutex_unlock(&userspace_mutex);
+	return ret;
+}
+
+static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
+{
+	return sprintf(buf, "%u\n", policy->cur);
+}
+
+static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
+				   unsigned int event)
+{
+	unsigned int cpu = policy->cpu;
+	int rc = 0;
+
+	switch (event) {
+	case CPUFREQ_GOV_START:
+		BUG_ON(!policy->cur);
+		pr_debug("started managing cpu %u\n", cpu);
+
+		mutex_lock(&userspace_mutex);
+		per_cpu(cpu_is_managed, cpu) = 1;
+		mutex_unlock(&userspace_mutex);
+		break;
+	case CPUFREQ_GOV_STOP:
+		pr_debug("managing cpu %u stopped\n", cpu);
+
+		mutex_lock(&userspace_mutex);
+		per_cpu(cpu_is_managed, cpu) = 0;
+		mutex_unlock(&userspace_mutex);
+		break;
+	case CPUFREQ_GOV_LIMITS:
+		mutex_lock(&userspace_mutex);
+		pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
+			cpu, policy->min, policy->max,
+			policy->cur);
+
+		if (policy->max < policy->cur)
+			__cpufreq_driver_target(policy, policy->max,
+						CPUFREQ_RELATION_H);
+		else if (policy->min > policy->cur)
+			__cpufreq_driver_target(policy, policy->min,
+						CPUFREQ_RELATION_L);
+		mutex_unlock(&userspace_mutex);
+		break;
+	}
+	return rc;
+}
+
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
+static
+#endif
+struct cpufreq_governor cpufreq_gov_userspace = {
+	.name		= "userspace",
+	.governor	= cpufreq_governor_userspace,
+	.store_setspeed	= cpufreq_set,
+	.show_setspeed	= show_speed,
+	.owner		= THIS_MODULE,
+};
+
+static int __init cpufreq_gov_userspace_init(void)
+{
+	return cpufreq_register_governor(&cpufreq_gov_userspace);
+}
+
+static void __exit cpufreq_gov_userspace_exit(void)
+{
+	cpufreq_unregister_governor(&cpufreq_gov_userspace);
+}
+
+MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
+		"Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
+MODULE_LICENSE("GPL");
+
+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
+fs_initcall(cpufreq_gov_userspace_init);
+#else
+module_init(cpufreq_gov_userspace_init);
+#endif
+module_exit(cpufreq_gov_userspace_exit);