Re: [PATCH V3 3/5] Thermal: Remove the cooling_cpufreq_list.

[Zhang Rui <rui.zhang@intel.com>]

On Tue, 2012-10-30 at 17:48 +0100, hongbo.zhang wrote:
> From: "hongbo.zhang" <hongbo.zhang@linaro.com>
> 
> 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>

applied to thermal-next.

thanks,
rui

> ---
>  drivers/thermal/cpu_cooling.c | 91 +++++++++----------------------------------
>  1 file changed, 19 insertions(+), 72 deletions(-)
> 
> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
> index bfd62b7..392d57d 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);