[RFC PATCH 04/19] cpufreq: bring data structures close to their locks

From: Juri Lelli
Date: Mon Jan 11 2016 - 12:42:14 EST


Currently it is not easy to figure out which lock/mutex protects which data
structure. Clean things up by moving data structures and their locks/mutexs
closer; also, change comments to document relations further.

Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Juri Lelli <juri.lelli@xxxxxxx>
---
drivers/cpufreq/cpufreq.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2e41356..00a00cd 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -31,7 +31,25 @@
#include <linux/tick.h>
#include <trace/events/power.h>

+/**
+ * Iterate over governors
+ *
+ * cpufreq_governor_list is protected by cpufreq_governor_mutex.
+ */
+static LIST_HEAD(cpufreq_governor_list);
+static DEFINE_MUTEX(cpufreq_governor_mutex);
+#define for_each_governor(__governor) \
+ list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
+
+/**
+ * The "cpufreq driver" - the arch- or hardware-dependent low
+ * level driver of CPUFreq support, and its spinlock (cpufreq_driver_lock).
+ * This lock also protects cpufreq_cpu_data array and cpufreq_policy_list.
+ */
+static struct cpufreq_driver *cpufreq_driver;
+static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
static LIST_HEAD(cpufreq_policy_list);
+static DEFINE_RWLOCK(cpufreq_driver_lock);

static inline bool policy_is_inactive(struct cpufreq_policy *policy)
{
@@ -86,21 +104,6 @@ static struct cpufreq_policy *first_policy(bool active)
#define for_each_inactive_policy(__policy) \
for_each_suitable_policy(__policy, false)

-/* Iterate over governors */
-static LIST_HEAD(cpufreq_governor_list);
-#define for_each_governor(__governor) \
- list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
-
-/**
- * The "cpufreq driver" - the arch- or hardware-dependent low
- * level driver of CPUFreq support, and its spinlock. This lock
- * also protects the cpufreq_cpu_data array.
- */
-static struct cpufreq_driver *cpufreq_driver;
-static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
-static DEFINE_RWLOCK(cpufreq_driver_lock);
-static DEFINE_MUTEX(cpufreq_governor_mutex);
-
/* Flag to suspend/resume CPUFreq governors */
static bool cpufreq_suspended;

--
2.2.2