cpufreq: governor: Get rid of governor events

The design of the cpufreq governor API is not very straightforward,
as struct cpufreq_governor provides only one callback to be invoked
from different code paths for different purposes.  The purpose it is
invoked for is determined by its second "event" argument, causing it
to act as a "callback multiplexer" of sorts.

Unfortunately, that leads to extra complexity in governors, some of
which implement the ->governor() callback as a switch statement
that simply checks the event argument and invokes a separate function
to handle that specific event.

That extra complexity can be eliminated by replacing the all-purpose
->governor() callback with a family of callbacks to carry out specific
governor operations: initialization and exit, start and stop and policy
limits updates.  That also turns out to reduce the code size too, so
do it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

1 files changed, 34 insertions, 38 deletions

diff --git a/arch/powerpc/platforms/cell/cpufreq_spudemand.c b/arch/powerpc/platforms/cell/cpufreq_spudemand.c
index 82607d621aca..88301e53f085 100644
--- a/arch/powerpc/platforms/cell/cpufreq_spudemand.c
+++ b/arch/powerpc/platforms/cell/cpufreq_spudemand.c
@@ -85,61 +85,57 @@ static void spu_gov_cancel_work(struct spu_gov_info_struct *info)
 	cancel_delayed_work_sync(&info->work);
 }
 
-static int spu_gov_govern(struct cpufreq_policy *policy, unsigned int event)
+static int spu_gov_start(struct cpufreq_policy *policy)
 {
 	unsigned int cpu = policy->cpu;
-	struct spu_gov_info_struct *info, *affected_info;
+	struct spu_gov_info_struct *info = &per_cpu(spu_gov_info, cpu);
+	struct spu_gov_info_struct *affected_info;
 	int i;
-	int ret = 0;
 
-	info = &per_cpu(spu_gov_info, cpu);
-
-	switch (event) {
-	case CPUFREQ_GOV_START:
-		if (!cpu_online(cpu)) {
-			printk(KERN_ERR "cpu %d is not online\n", cpu);
-			ret = -EINVAL;
-			break;
-		}
+	if (!cpu_online(cpu)) {
+		printk(KERN_ERR "cpu %d is not online\n", cpu);
+		return -EINVAL;
+	}
 
-		if (!policy->cur) {
-			printk(KERN_ERR "no cpu specified in policy\n");
-			ret = -EINVAL;
-			break;
-		}
+	if (!policy->cur) {
+		printk(KERN_ERR "no cpu specified in policy\n");
+		return -EINVAL;
+	}
 
-		/* initialize spu_gov_info for all affected cpus */
-		for_each_cpu(i, policy->cpus) {
-			affected_info = &per_cpu(spu_gov_info, i);
-			affected_info->policy = policy;
-		}
+	/* initialize spu_gov_info for all affected cpus */
+	for_each_cpu(i, policy->cpus) {
+		affected_info = &per_cpu(spu_gov_info, i);
+		affected_info->policy = policy;
+	}
 
-		info->poll_int = POLL_TIME;
+	info->poll_int = POLL_TIME;
 
-		/* setup timer */
-		spu_gov_init_work(info);
+	/* setup timer */
+	spu_gov_init_work(info);
 
-		break;
+	return 0;
+}
 
-	case CPUFREQ_GOV_STOP:
-		/* cancel timer */
-		spu_gov_cancel_work(info);
+static void spu_gov_stop(struct cpufreq_policy *policy)
+{
+	unsigned int cpu = policy->cpu;
+	struct spu_gov_info_struct *info = &per_cpu(spu_gov_info, cpu);
+	int i;
 
-		/* clean spu_gov_info for all affected cpus */
-		for_each_cpu (i, policy->cpus) {
-			info = &per_cpu(spu_gov_info, i);
-			info->policy = NULL;
-		}
+	/* cancel timer */
+	spu_gov_cancel_work(info);
 
-		break;
+	/* clean spu_gov_info for all affected cpus */
+	for_each_cpu (i, policy->cpus) {
+		info = &per_cpu(spu_gov_info, i);
+		info->policy = NULL;
 	}
-
-	return ret;
 }
 
 static struct cpufreq_governor spu_governor = {
 	.name = "spudemand",
-	.governor = spu_gov_govern,
+	.start = spu_gov_start,
+	.stop = spu_gov_stop,
 	.owner = THIS_MODULE,
 };