1 files changed, 55 insertions, 139 deletions

diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index d32bf3593cd..4dbf1db16ac 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -1,3 +1,4 @@
+
 /*
  *  linux/drivers/cpufreq/cpufreq_userspace.c
  *
@@ -10,198 +11,113 @@
  *
  */
 
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/smp.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
-#include <linux/cpufreq.h>
-#include <linux/types.h>
-#include <linux/fs.h>
-#include <linux/sysfs.h>
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <asm/uaccess.h>
+#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);
 
 /**
- * A few values needed by the userspace governor
- */
-static unsigned int	cpu_max_freq[NR_CPUS];
-static unsigned int	cpu_min_freq[NR_CPUS];
-static unsigned int	cpu_cur_freq[NR_CPUS]; /* current CPU freq */
-static unsigned int	cpu_set_freq[NR_CPUS]; /* CPU freq desired by userspace */
-static unsigned int	cpu_is_managed[NR_CPUS];
-static struct cpufreq_policy current_policy[NR_CPUS];
-
-static DECLARE_MUTEX	(userspace_sem); 
-
-#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "userspace", msg)
-
-/* keep track of frequency transitions */
-static int 
-userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
-                       void *data)
-{
-        struct cpufreq_freqs *freq = data;
-
-	dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n", freq->cpu, freq->new);
-	cpu_cur_freq[freq->cpu] = freq->new;
-
-        return 0;
-}
-
-static struct notifier_block userspace_cpufreq_notifier_block = {
-        .notifier_call  = userspace_cpufreq_notifier
-};
-
-
-/** 
  * cpufreq_set - set the CPU frequency
+ * @policy: pointer to policy struct where freq is being set
  * @freq: target frequency in kHz
- * @cpu: CPU for which the frequency is to be set
  *
  * Sets the CPU frequency to freq.
  */
-static int cpufreq_set(unsigned int freq, unsigned int cpu)
+static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
 {
 	int ret = -EINVAL;
 
-	dprintk("cpufreq_set for cpu %u, freq %u kHz\n", cpu, freq);
+	pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
 
-	down(&userspace_sem);
-	if (!cpu_is_managed[cpu])
+	mutex_lock(&userspace_mutex);
+	if (!per_cpu(cpu_is_managed, policy->cpu))
 		goto err;
 
-	cpu_set_freq[cpu] = freq;
-
-	if (freq < cpu_min_freq[cpu])
-		freq = cpu_min_freq[cpu];
-	if (freq > cpu_max_freq[cpu])
-		freq = cpu_max_freq[cpu];
-
-	/*
-	 * We're safe from concurrent calls to ->target() here
-	 * as we hold the userspace_sem lock. If we were calling
-	 * cpufreq_driver_target, a deadlock situation might occur:
-	 * A: cpufreq_set (lock userspace_sem) -> cpufreq_driver_target(lock policy->lock)
-	 * B: cpufreq_set_policy(lock policy->lock) -> __cpufreq_governor -> cpufreq_governor_userspace (lock userspace_sem)
-	 */
-	ret = __cpufreq_driver_target(&current_policy[cpu], freq, 
-	      CPUFREQ_RELATION_L);
-
+	ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
  err:
-	up(&userspace_sem);
+	mutex_unlock(&userspace_mutex);
 	return ret;
 }
 
-
-/************************** sysfs interface ************************/
-static ssize_t show_speed (struct cpufreq_policy *policy, char *buf)
-{
-	return sprintf (buf, "%u\n", cpu_cur_freq[policy->cpu]);
-}
-
-static ssize_t 
-store_speed (struct cpufreq_policy *policy, const char *buf, size_t count) 
+static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
 {
-	unsigned int freq = 0;
-	unsigned int ret;
-
-	ret = sscanf (buf, "%u", &freq);
-	if (ret != 1)
-		return -EINVAL;
-
-	cpufreq_set(freq, policy->cpu);
-
-	return count;
+	return sprintf(buf, "%u\n", policy->cur);
 }
 
-static struct freq_attr freq_attr_scaling_setspeed = 
-{
-	.attr = { .name = "scaling_setspeed", .mode = 0644, .owner = THIS_MODULE },
-	.show = show_speed,
-	.store = store_speed,
-};
-
 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:
-		if (!cpu_online(cpu))
-			return -EINVAL;
 		BUG_ON(!policy->cur);
-		down(&userspace_sem);
-		cpu_is_managed[cpu] = 1;		
-		cpu_min_freq[cpu] = policy->min;
-		cpu_max_freq[cpu] = policy->max;
-		cpu_cur_freq[cpu] = policy->cur;
-		cpu_set_freq[cpu] = policy->cur;
-		sysfs_create_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
-		memcpy (&current_policy[cpu], policy, sizeof(struct cpufreq_policy));
-		dprintk("managing cpu %u started (%u - %u kHz, currently %u kHz)\n", cpu, cpu_min_freq[cpu], cpu_max_freq[cpu], cpu_cur_freq[cpu]);
-		up(&userspace_sem);
+		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:
-		down(&userspace_sem);
-		cpu_is_managed[cpu] = 0;
-		cpu_min_freq[cpu] = 0;
-		cpu_max_freq[cpu] = 0;
-		cpu_set_freq[cpu] = 0;
-		sysfs_remove_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
-		dprintk("managing cpu %u stopped\n", cpu);
-		up(&userspace_sem);
+		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:
-		down(&userspace_sem);
-		cpu_min_freq[cpu] = policy->min;
-		cpu_max_freq[cpu] = policy->max;
-		dprintk("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n", cpu, cpu_min_freq[cpu], cpu_max_freq[cpu], cpu_cur_freq[cpu], cpu_set_freq[cpu]);
-		if (policy->max < cpu_set_freq[cpu]) {
-			__cpufreq_driver_target(&current_policy[cpu], policy->max, 
-			      CPUFREQ_RELATION_H);
-		} else if (policy->min > cpu_set_freq[cpu]) {
-			__cpufreq_driver_target(&current_policy[cpu], policy->min, 
-			      CPUFREQ_RELATION_L);
-		} else {
-			__cpufreq_driver_target(&current_policy[cpu], cpu_set_freq[cpu],
-			      CPUFREQ_RELATION_L);
-		}
-		memcpy (&current_policy[cpu], policy, sizeof(struct cpufreq_policy));
-		up(&userspace_sem);
+		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 0;
+	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,
 };
-EXPORT_SYMBOL(cpufreq_gov_userspace);
 
 static int __init cpufreq_gov_userspace_init(void)
 {
-	cpufreq_register_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 	return cpufreq_register_governor(&cpufreq_gov_userspace);
 }
 
-
 static void __exit cpufreq_gov_userspace_exit(void)
 {
 	cpufreq_unregister_governor(&cpufreq_gov_userspace);
-        cpufreq_unregister_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 }
 
+MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
+		"Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
+MODULE_LICENSE("GPL");
 
-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);