From: Alex Chiang <achiang@redhat.com>
Date: Wed, 23 Sep 2009 21:04:23 -0400
Subject: [cpufreq] change cpu freq arrays to per_cpu variables
Message-id: <20090923210423.GE30562@algore>
Patchwork-id: 20950
O-Subject: [RHEL 5.5 BZ523505 Patch 4/5] [CPUFREQ] change cpu freq arrays to
	per_cpu variables
Bugzilla: 523505
RH-Acked-by: Dave Jones <davej@redhat.com>
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>

Backport of upstream, but minus the cpufreq_governor stuff since
it's not in RHEL5:

	commit 7a6aedfac98c6d54ecf97ca1ffb1e6a1f3d26aea
	Author: Mike Travis <travis@sgi.com>
	Date:   Tue Mar 25 15:06:53 2008 -0700

	[CPUFREQ] change cpu freq arrays to per_cpu variables

	Change cpufreq_policy and cpufreq_governor pointer tables
	from arrays to per_cpu variables in the cpufreq subsystem.

	Also some minor complaints from checkpatch.pl fixed.

	Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

	Signed-off-by: Mike Travis <travis@sgi.com>
	Signed-off-by: Dave Jones <davej@redhat.com>

There is one extra reference to cpufreq_cpu_data[cpu] which was introduced
into RHEL5 by c32b6b8e. Upstream no longer has that line, but I updated
in this patch.

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index a6199fe..6e72f61 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -37,7 +37,7 @@
  * also protects the cpufreq_cpu_data array.
  */
 static struct cpufreq_driver *cpufreq_driver;
-static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
 static DEFINE_SPINLOCK(cpufreq_driver_lock);
 
 /*
@@ -136,7 +136,7 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 
 
 	/* get the CPU */
-	data = cpufreq_cpu_data[cpu];
+	data = per_cpu(cpufreq_cpu_data, cpu);
 
 	if (!data)
 		goto err_out_put_module;
@@ -304,7 +304,7 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
 	dprintk("notification %u of frequency transition to %u kHz\n",
 		state, freqs->new);
 
-	policy = cpufreq_cpu_data[freqs->cpu];
+	policy = per_cpu(cpufreq_cpu_data, freqs->cpu);
 	switch (state) {
 
 	case CPUFREQ_PRECHANGE:
@@ -762,7 +762,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 
 			spin_lock_irqsave(&cpufreq_driver_lock, flags);
 			managed_policy->cpus = policy->cpus;
-			cpufreq_cpu_data[cpu] = managed_policy;
+			per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
 			spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
 			dprintk("CPU already managed, adding link\n");
@@ -803,7 +803,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 	for_each_cpu_mask(j, policy->cpus) {
 		if (!cpu_online(j))
 			continue;
-		cpufreq_cpu_data[j] = policy;
+		per_cpu(cpufreq_cpu_data, j) = policy;
 		per_cpu(policy_cpu, j) = policy->cpu;
 	}
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
@@ -846,7 +846,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 err_out_unregister:
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	for_each_cpu_mask(j, policy->cpus)
-		cpufreq_cpu_data[j] = NULL;
+		per_cpu(cpufreq_cpu_data, j) = NULL;
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
 	kobject_unregister(&policy->kobj);
@@ -888,7 +888,7 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev)
 	dprintk("unregistering CPU %u\n", cpu);
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
-	data = cpufreq_cpu_data[cpu];
+	data = per_cpu(cpufreq_cpu_data, cpu);
 
 	if (!data) {
 		spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
@@ -896,7 +896,7 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev)
 		unlock_policy_rwsem_write(cpu);
 		return -EINVAL;
 	}
-	cpufreq_cpu_data[cpu] = NULL;
+	per_cpu(cpufreq_cpu_data, cpu) = NULL;
 
 #ifdef CONFIG_SMP
 	/* if this isn't the CPU which is the parent of the kobj, we
@@ -925,14 +925,14 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev)
 #ifdef CONFIG_SMP
 	/* if we have other CPUs still registered, we need to unlink them,
 	 * or else wait_for_completion below will lock up. Clean the
-	 * cpufreq_cpu_data[] while holding the lock, and remove the sysfs
-	 * links afterwards.
+	 * per_cpu(cpufreq_cpu_data) while holding the lock, and remove the
+	 * sysfs links afterwards.
 	 */
 	if (unlikely(cpus_weight(data->cpus) > 1)) {
 		for_each_cpu_mask(j, data->cpus) {
 			if (j == cpu)
 				continue;
-			cpufreq_cpu_data[j] = NULL;
+			per_cpu(cpufreq_cpu_data, j) = NULL;
 		}
 	}
 
@@ -1049,7 +1049,7 @@ EXPORT_SYMBOL(cpufreq_quick_get);
 
 static unsigned int __cpufreq_get(unsigned int cpu)
 {
-	struct cpufreq_policy *policy = cpufreq_cpu_data[cpu];
+	struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
 	unsigned int ret = 0;
 
 	if (!cpufreq_driver->get)
@@ -1676,7 +1676,7 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
 			if (unlikely(lock_policy_rwsem_write(cpu)))
 				BUG();
 
-			policy = cpufreq_cpu_data[cpu];
+			policy = per_cpu(cpufreq_cpu_data, cpu);
 			if (policy) {
 				__cpufreq_driver_target(policy, policy->min,
 						CPUFREQ_RELATION_H);
@@ -1733,7 +1733,8 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
 	cpufreq_driver = driver_data;
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
-	ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver);
+	ret = sysdev_driver_register(&cpu_sysdev_class,
+					&cpufreq_sysdev_driver);
 
 	if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) {
 		int i;
@@ -1741,8 +1742,10 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
 
 		/* check for at least one working CPU */
 		for (i=0; i<NR_CPUS; i++)
-			if (cpufreq_cpu_data[i])
+			if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
 				ret = 0;
+				break;
+			}
 
 		/* if all ->init() calls failed, unregister */
 		if (ret) {
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 86a5603..c659acd 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -44,7 +44,7 @@ struct cpufreq_stats {
 #endif
 };
 
-static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
 
 struct cpufreq_stats_attribute {
 	struct attribute attr;
@@ -59,7 +59,7 @@ cpufreq_stats_update (unsigned int cpu)
 
 	cur_time = get_jiffies_64();
 	spin_lock(&cpufreq_stats_lock);
-	stat = cpufreq_stats_table[cpu];
+	stat = per_cpu(cpufreq_stats_table, cpu);
 	if (stat->time_in_state)
 		stat->time_in_state[stat->last_index] =
 			cputime64_add(stat->time_in_state[stat->last_index],
@@ -72,11 +72,11 @@ cpufreq_stats_update (unsigned int cpu)
 static ssize_t
 show_total_trans(struct cpufreq_policy *policy, char *buf)
 {
-	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 	if (!stat)
 		return 0;
 	return sprintf(buf, "%d\n",
-			cpufreq_stats_table[stat->cpu]->total_trans);
+			per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
 }
 
 static ssize_t
@@ -84,7 +84,7 @@ show_time_in_state(struct cpufreq_policy *policy, char *buf)
 {
 	ssize_t len = 0;
 	int i;
-	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 	if (!stat)
 		return 0;
 	cpufreq_stats_update(stat->cpu);
@@ -102,7 +102,7 @@ show_trans_table(struct cpufreq_policy *policy, char *buf)
 	ssize_t len = 0;
 	int i, j;
 
-	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 	if (!stat)
 		return 0;
 	cpufreq_stats_update(stat->cpu);
@@ -168,7 +168,7 @@ freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
 static void
 cpufreq_stats_free_table (unsigned int cpu)
 {
-	struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 	if (policy && policy->cpu == cpu)
 		sysfs_remove_group(&policy->kobj, &stats_attr_group);
@@ -176,7 +176,7 @@ cpufreq_stats_free_table (unsigned int cpu)
 		kfree(stat->time_in_state);
 		kfree(stat);
 	}
-	cpufreq_stats_table[cpu] = NULL;
+	per_cpu(cpufreq_stats_table, cpu) = NULL;
 	if (policy)
 		cpufreq_cpu_put(policy);
 }
@@ -190,7 +190,7 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
 	struct cpufreq_policy *data;
 	unsigned int alloc_size;
 	unsigned int cpu = policy->cpu;
-	if (cpufreq_stats_table[cpu])
+	if (per_cpu(cpufreq_stats_table, cpu))
 		return -EBUSY;
 	if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
 		return -ENOMEM;
@@ -205,7 +205,7 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
 		goto error_out;
 
 	stat->cpu = cpu;
-	cpufreq_stats_table[cpu] = stat;
+	per_cpu(cpufreq_stats_table, cpu) = stat;
 
 	for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
 		unsigned int freq = table[i].frequency;
@@ -249,7 +249,7 @@ error_out:
 	cpufreq_cpu_put(data);
 error_get_fail:
 	kfree(stat);
-	cpufreq_stats_table[cpu] = NULL;
+	per_cpu(cpufreq_stats_table, cpu) = NULL;
 	return ret;
 }
 
@@ -282,7 +282,7 @@ cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
 	if (val != CPUFREQ_POSTCHANGE)
 		return 0;
 
-	stat = cpufreq_stats_table[freq->cpu];
+	stat = per_cpu(cpufreq_stats_table, freq->cpu);
 	if (!stat)
 		return 0;
 	old_index = freq_table_get_index(stat, freq->old);
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 551f4cc..429fb39 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -164,7 +164,7 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
 
-static struct cpufreq_frequency_table *show_table[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_frequency_table *, show_table);
 /**
  * show_scaling_governor - show the current policy for the specified CPU
  */
@@ -175,10 +175,10 @@ static ssize_t show_available_freqs (struct cpufreq_policy *policy, char *buf)
 	ssize_t count = 0;
 	struct cpufreq_frequency_table *table;
 
-	if (!show_table[cpu])
+	if (!per_cpu(show_table, cpu))
 		return -ENODEV;
 
-	table = show_table[cpu];
+	table = per_cpu(show_table, cpu);
 
 	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
@@ -205,20 +205,20 @@ void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 				      unsigned int cpu)
 {
 	dprintk("setting show_table for cpu %u to %p\n", cpu, table);
-	show_table[cpu] = table;
+	per_cpu(show_table, cpu) = table;
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
 
 void cpufreq_frequency_table_put_attr(unsigned int cpu)
 {
 	dprintk("clearing show_table for cpu %u\n", cpu);
-	show_table[cpu] = NULL;
+	per_cpu(show_table, cpu) = NULL;
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
 
 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
 {
-	return show_table[cpu];
+	return per_cpu(show_table, cpu);
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);