[CPUFREQ] Remove unneeded locks

There cannot be any concurrent access to these through
different cpu sysfs files anymore, because these tunables
are now all global (not per cpu).

I still have some doubts whether some of these locks
were needed at all. Anyway, let's get rid of them.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org

2 files changed, 6 insertions, 53 deletions

diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 3182d85b3374..33b56e5c5c14 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -76,8 +76,7 @@ static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info);
 static unsigned int dbs_enable; /* number of CPUs using this policy */
 
 /*
- * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
- * different CPUs. It protects dbs_enable in governor start/stop.
+ * dbs_mutex protects dbs_enable in governor start/stop.
  */
 static DEFINE_MUTEX(dbs_mutex);
 
@@ -195,10 +194,7 @@ static ssize_t store_sampling_down_factor(struct kobject *a,
         if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
                 return -EINVAL;
 
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.sampling_down_factor = input;
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -212,10 +208,7 @@ static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
         if (ret != 1)
                 return -EINVAL;
 
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -226,16 +219,11 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
         int ret;
         ret = sscanf(buf, "%u", &input);
 
-        mutex_lock(&dbs_mutex);
         if (ret != 1 || input > 100 ||
-                        input <= dbs_tuners_ins.down_threshold) {
-                mutex_unlock(&dbs_mutex);
+                        input <= dbs_tuners_ins.down_threshold)
                 return -EINVAL;
-        }
 
         dbs_tuners_ins.up_threshold = input;
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -246,17 +234,12 @@ static ssize_t store_down_threshold(struct kobject *a, struct attribute *b,
         int ret;
         ret = sscanf(buf, "%u", &input);
 
-        mutex_lock(&dbs_mutex);
         /* cannot be lower than 11 otherwise freq will not fall */
         if (ret != 1 || input < 11 || input > 100 ||
-                        input >= dbs_tuners_ins.up_threshold) {
-                mutex_unlock(&dbs_mutex);
+                        input >= dbs_tuners_ins.up_threshold)
                 return -EINVAL;
-        }
 
         dbs_tuners_ins.down_threshold = input;
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -275,11 +258,9 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
         if (input > 1)
                 input = 1;
 
-        mutex_lock(&dbs_mutex);
-        if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
-                mutex_unlock(&dbs_mutex);
+        if (input == dbs_tuners_ins.ignore_nice) /* nothing to do */
                 return count;
-        }
+
         dbs_tuners_ins.ignore_nice = input;
 
         /* we need to re-evaluate prev_cpu_idle */
@@ -291,8 +272,6 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
                 if (dbs_tuners_ins.ignore_nice)
                         dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
         }
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -311,10 +290,7 @@ static ssize_t store_freq_step(struct kobject *a, struct attribute *b,
 
         /* no need to test here if freq_step is zero as the user might actually
          * want this, they would be crazy though :) */
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.freq_step = input;
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index ba18205be12b..891360edecdd 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -99,8 +99,7 @@ static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info);
 static unsigned int dbs_enable; /* number of CPUs using this policy */
 
 /*
- * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
- * different CPUs. It protects dbs_enable in governor start/stop.
+ * dbs_mutex protects dbs_enable in governor start/stop.
  */
 static DEFINE_MUTEX(dbs_mutex);
 
@@ -265,11 +264,7 @@ static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
         ret = sscanf(buf, "%u", &input);
         if (ret != 1)
                 return -EINVAL;
-
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -282,11 +277,7 @@ static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
         ret = sscanf(buf, "%u", &input);
         if (ret != 1)
                 return -EINVAL;
-
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.io_is_busy = !!input;
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -301,11 +292,7 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
                         input < MIN_FREQUENCY_UP_THRESHOLD) {
                 return -EINVAL;
         }
-
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.up_threshold = input;
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -318,7 +305,6 @@ static ssize_t store_sampling_down_factor(struct kobject *a,
 
         if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
                 return -EINVAL;
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.sampling_down_factor = input;
 
         /* Reset down sampling multiplier in case it was active */
@@ -327,8 +313,6 @@ static ssize_t store_sampling_down_factor(struct kobject *a,
                 dbs_info = &per_cpu(od_cpu_dbs_info, j);
                 dbs_info->rate_mult = 1;
         }
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -347,9 +331,7 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
         if (input > 1)
                 input = 1;
 
-        mutex_lock(&dbs_mutex);
         if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
-                mutex_unlock(&dbs_mutex);
                 return count;
         }
         dbs_tuners_ins.ignore_nice = input;
@@ -364,8 +346,6 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
                         dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
 
         }
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }
 
@@ -382,11 +362,8 @@ static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
         if (input > 1000)
                 input = 1000;
 
-        mutex_lock(&dbs_mutex);
         dbs_tuners_ins.powersave_bias = input;
         ondemand_powersave_bias_init();
-        mutex_unlock(&dbs_mutex);
-
         return count;
 }