Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / cpufreq / cpufreq_userspace.c

diff --git a/kernel/drivers/cpufreq/cpufreq_userspace.c b/kernel/drivers/cpufreq/cpufreq_userspace.c
new file mode 100644 (file)
index 0000000..4dbf1db
--- /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);