v4.19.13 snapshot.
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
new file mode 100644
index 0000000..bd897e3
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -0,0 +1,158 @@
+
+/*
+ * 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>
+#include <linux/slab.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;
+ unsigned int *setspeed = policy->governor_data;
+
+ 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;
+
+ *setspeed = freq;
+
+ 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_userspace_policy_init(struct cpufreq_policy *policy)
+{
+ unsigned int *setspeed;
+
+ setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
+ if (!setspeed)
+ return -ENOMEM;
+
+ policy->governor_data = setspeed;
+ return 0;
+}
+
+static void cpufreq_userspace_policy_exit(struct cpufreq_policy *policy)
+{
+ mutex_lock(&userspace_mutex);
+ kfree(policy->governor_data);
+ policy->governor_data = NULL;
+ mutex_unlock(&userspace_mutex);
+}
+
+static int cpufreq_userspace_policy_start(struct cpufreq_policy *policy)
+{
+ unsigned int *setspeed = policy->governor_data;
+
+ BUG_ON(!policy->cur);
+ pr_debug("started managing cpu %u\n", policy->cpu);
+
+ mutex_lock(&userspace_mutex);
+ per_cpu(cpu_is_managed, policy->cpu) = 1;
+ *setspeed = policy->cur;
+ mutex_unlock(&userspace_mutex);
+ return 0;
+}
+
+static void cpufreq_userspace_policy_stop(struct cpufreq_policy *policy)
+{
+ unsigned int *setspeed = policy->governor_data;
+
+ pr_debug("managing cpu %u stopped\n", policy->cpu);
+
+ mutex_lock(&userspace_mutex);
+ per_cpu(cpu_is_managed, policy->cpu) = 0;
+ *setspeed = 0;
+ mutex_unlock(&userspace_mutex);
+}
+
+static void cpufreq_userspace_policy_limits(struct cpufreq_policy *policy)
+{
+ unsigned int *setspeed = policy->governor_data;
+
+ mutex_lock(&userspace_mutex);
+
+ pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n",
+ policy->cpu, policy->min, policy->max, policy->cur, *setspeed);
+
+ if (policy->max < *setspeed)
+ __cpufreq_driver_target(policy, policy->max, CPUFREQ_RELATION_H);
+ else if (policy->min > *setspeed)
+ __cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L);
+ else
+ __cpufreq_driver_target(policy, *setspeed, CPUFREQ_RELATION_L);
+
+ mutex_unlock(&userspace_mutex);
+}
+
+static struct cpufreq_governor cpufreq_gov_userspace = {
+ .name = "userspace",
+ .init = cpufreq_userspace_policy_init,
+ .exit = cpufreq_userspace_policy_exit,
+ .start = cpufreq_userspace_policy_start,
+ .stop = cpufreq_userspace_policy_stop,
+ .limits = cpufreq_userspace_policy_limits,
+ .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
+struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return &cpufreq_gov_userspace;
+}
+
+fs_initcall(cpufreq_gov_userspace_init);
+#else
+module_init(cpufreq_gov_userspace_init);
+#endif
+module_exit(cpufreq_gov_userspace_exit);