Thermal: Remove the cooling_cpufreq_list.

Problem of using this list is that the cpufreq_get_max_state callback will be
called when register cooling device by thermal_cooling_device_register, but
this list isn't ready at this moment. What's more, there is no need to maintain
such a list, we can get cpufreq_cooling_device instance by the private
thermal_cooling_device.devdata.

Signed-off-by: hongbo.zhang <hongbo.zhang@linaro.com>
Reviewed-by: Francesco Lavra <francescolavra.fl@gmail.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 19 insertions, 72 deletions

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index bfd62b7f32a7..392d57d8590d 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -58,8 +58,9 @@ struct cpufreq_cooling_device {
 };
 static LIST_HEAD(cooling_cpufreq_list);
 static DEFINE_IDR(cpufreq_idr);
+static DEFINE_MUTEX(cooling_cpufreq_lock);
 
-static struct mutex cooling_cpufreq_lock;
+static unsigned int cpufreq_dev_count;
 
 /* notify_table passes value to the CPUFREQ_ADJUST callback function. */
 #define NOTIFY_INVALID NULL
@@ -240,28 +241,18 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
 static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
                                  unsigned long *state)
 {
-        int ret = -EINVAL, i = 0;
-        struct cpufreq_cooling_device *cpufreq_device;
-        struct cpumask *maskPtr;
+        struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
+        struct cpumask *maskPtr = &cpufreq_device->allowed_cpus;
         unsigned int cpu;
         struct cpufreq_frequency_table *table;
         unsigned long count = 0;
+        int i = 0;
 
-        mutex_lock(&cooling_cpufreq_lock);
-        list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) {
-                if (cpufreq_device && cpufreq_device->cool_dev == cdev)
-                        break;
-        }
-        if (cpufreq_device == NULL)
-                goto return_get_max_state;
-
-        maskPtr = &cpufreq_device->allowed_cpus;
         cpu = cpumask_any(maskPtr);
         table = cpufreq_frequency_get_table(cpu);
         if (!table) {
                 *state = 0;
-                ret = 0;
-                goto return_get_max_state;
+                return 0;
         }
 
         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
@@ -272,12 +263,10 @@ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
 
         if (count > 0) {
                 *state = --count;
-                ret = 0;
+                return 0;
         }
 
-return_get_max_state:
-        mutex_unlock(&cooling_cpufreq_lock);
-        return ret;
+        return -EINVAL;
 }
 
 /**
@@ -288,20 +277,10 @@ return_get_max_state:
 static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
                                  unsigned long *state)
 {
-        int ret = -EINVAL;
-        struct cpufreq_cooling_device *cpufreq_device;
+        struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
 
-        mutex_lock(&cooling_cpufreq_lock);
-        list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) {
-                if (cpufreq_device && cpufreq_device->cool_dev == cdev) {
-                        *state = cpufreq_device->cpufreq_state;
-                        ret = 0;
-                        break;
-                }
-        }
-        mutex_unlock(&cooling_cpufreq_lock);
-
-        return ret;
+        *state = cpufreq_device->cpufreq_state;
+        return 0;
 }
 
 /**
@@ -312,22 +291,9 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
 static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
                                  unsigned long state)
 {
-        int ret = -EINVAL;
-        struct cpufreq_cooling_device *cpufreq_device;
+        struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
 
-        mutex_lock(&cooling_cpufreq_lock);
-        list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) {
-                if (cpufreq_device && cpufreq_device->cool_dev == cdev) {
-                        ret = 0;
-                        break;
-                }
-        }
-        if (!ret)
-                ret = cpufreq_apply_cooling(cpufreq_device, state);
-
-        mutex_unlock(&cooling_cpufreq_lock);
-
-        return ret;
+        return cpufreq_apply_cooling(cpufreq_device, state);
 }
 
 /* Bind cpufreq callbacks to thermal cooling device ops */
@@ -351,14 +317,11 @@ struct thermal_cooling_device *cpufreq_cooling_register(
 {
         struct thermal_cooling_device *cool_dev;
         struct cpufreq_cooling_device *cpufreq_dev = NULL;
-        unsigned int cpufreq_dev_count = 0, min = 0, max = 0;
+        unsigned int min = 0, max = 0;
         char dev_name[THERMAL_NAME_LENGTH];
         int ret = 0, i;
         struct cpufreq_policy policy;
 
-        list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node)
-                cpufreq_dev_count++;
-
         /*Verify that all the clip cpus have same freq_min, freq_max limit*/
         for_each_cpu(i, clip_cpus) {
                 /*continue if cpufreq policy not found and not return error*/
@@ -380,9 +343,6 @@ struct thermal_cooling_device *cpufreq_cooling_register(
 
         cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
 
-        if (cpufreq_dev_count == 0)
-                mutex_init(&cooling_cpufreq_lock);
-
         ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
         if (ret) {
                 kfree(cpufreq_dev);
@@ -401,12 +361,12 @@ struct thermal_cooling_device *cpufreq_cooling_register(
         cpufreq_dev->cool_dev = cool_dev;
         cpufreq_dev->cpufreq_state = 0;
         mutex_lock(&cooling_cpufreq_lock);
-        list_add_tail(&cpufreq_dev->node, &cooling_cpufreq_list);
 
         /* Register the notifier for first cpufreq cooling device */
         if (cpufreq_dev_count == 0)
                 cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
                                                 CPUFREQ_POLICY_NOTIFIER);
+        cpufreq_dev_count++;
 
         mutex_unlock(&cooling_cpufreq_lock);
         return cool_dev;
@@ -419,33 +379,20 @@ EXPORT_SYMBOL(cpufreq_cooling_register);
  */
 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
 {
-        struct cpufreq_cooling_device *cpufreq_dev = NULL;
-        unsigned int cpufreq_dev_count = 0;
+        struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata;
 
         mutex_lock(&cooling_cpufreq_lock);
-        list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) {
-                if (cpufreq_dev && cpufreq_dev->cool_dev == cdev)
-                        break;
-                cpufreq_dev_count++;
-        }
-
-        if (!cpufreq_dev || cpufreq_dev->cool_dev != cdev) {
-                mutex_unlock(&cooling_cpufreq_lock);
-                return;
-        }
-
-        list_del(&cpufreq_dev->node);
+        cpufreq_dev_count--;
 
         /* Unregister the notifier for the last cpufreq cooling device */
-        if (cpufreq_dev_count == 1) {
+        if (cpufreq_dev_count == 0) {
                 cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
                                         CPUFREQ_POLICY_NOTIFIER);
         }
         mutex_unlock(&cooling_cpufreq_lock);
+
         thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
         release_idr(&cpufreq_idr, cpufreq_dev->id);
-        if (cpufreq_dev_count == 1)
-                mutex_destroy(&cooling_cpufreq_lock);
         kfree(cpufreq_dev);
 }
 EXPORT_SYMBOL(cpufreq_cooling_unregister);