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Message-ID: <CADGdYn7unRYHmG-i_taUhVft_tNE4J0fHKNnb5THY27_JjgOiQ@mail.gmail.com>
Date: Mon, 19 May 2014 14:25:13 +0530
From: amit daniel kachhap <amit.daniel@...sung.com>
To: Eduardo Valentin <edubezval@...il.com>
Cc: rjw@...ysocki.net, linux-kernel@...r.kernel.org,
linux-acpi@...r.kernel.org, linux-pm@...ts.linux-foundation.org,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [linux-pm] [RFC PATCH 1/5] thermal: cpu_cooling: Support passing
driver private data.
Hi Eduardo,
Thanks for reviewing these patches.
On Fri, May 16, 2014 at 12:03 AM, Eduardo Valentin <edubezval@...il.com> wrote:
> Hello Amit,
>
>
> On Thu, May 08, 2014 at 08:07:56PM +0530, Amit Daniel Kachhap wrote:
>> This patch is in preparation to add notfication support for cpufrequency
>> cooling changes. This change also removes the unnecessary exposing of
>> internal housekeeping structure via thermal_cooling_device->devdata to the
>> users of cpufreq cooling APIs.
>>
>> Signed-off-by: Amit Daniel Kachhap <amit.daniel@...sung.com>
>> ---
>> drivers/thermal/cpu_cooling.c | 79 +++++++++++++++----
>> drivers/thermal/db8500_cpufreq_cooling.c | 2 +-
>> drivers/thermal/samsung/exynos_thermal_common.c | 2 +-
>> drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 2 +-
>> include/linux/cpu_cooling.h | 5 +-
>> 5 files changed, 68 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
>> index 4246262..21f44d4 100644
>> --- a/drivers/thermal/cpu_cooling.c
>> +++ b/drivers/thermal/cpu_cooling.c
>> @@ -50,16 +50,18 @@ struct cpufreq_cooling_device {
>> unsigned int cpufreq_state;
>> unsigned int cpufreq_val;
>> struct cpumask allowed_cpus;
>> + struct list_head node;
>> };
>> static DEFINE_IDR(cpufreq_idr);
>> static DEFINE_MUTEX(cooling_cpufreq_lock);
>>
>> -static unsigned int cpufreq_dev_count;
>> -
>> /* notify_table passes value to the CPUFREQ_ADJUST callback function. */
>> #define NOTIFY_INVALID NULL
>> static struct cpufreq_cooling_device *notify_device;
>>
>> +/* A list to hold all the cpufreq cooling devices registered */
>> +static LIST_HEAD(cpufreq_cooling_list);
>> +
>> /**
>> * get_idr - function to get a unique id.
>> * @idr: struct idr * handle used to create a id.
>> @@ -357,12 +359,23 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
>> static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
>> unsigned long *state)
>> {
>> - struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
>> - struct cpumask *mask = &cpufreq_device->allowed_cpus;
>> + struct cpufreq_cooling_device *cpufreq_device = NULL;
>> + struct cpumask *mask = NULL;
>> unsigned int cpu;
>> unsigned int count = 0;
>> int ret;
>>
>> + mutex_lock(&cooling_cpufreq_lock);
>> + list_for_each_entry(cpufreq_device, &cpufreq_cooling_list, node)
>> + if (cpufreq_device->cool_dev == cdev)
>> + break;
>> + mutex_unlock(&cooling_cpufreq_lock);
>> + if (!cpufreq_device) {
>> + /* Cooling device pointer not found */
>> + return -EINVAL;
>> + }
>> +
>> + mask = &cpufreq_device->allowed_cpus;
>> cpu = cpumask_any(mask);
>>
>> ret = get_property(cpu, 0, &count, GET_MAXL);
>> @@ -386,7 +399,17 @@ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
>> static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
>> unsigned long *state)
>> {
>> - struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
>> + struct cpufreq_cooling_device *cpufreq_device = NULL;
>> +
>> + mutex_lock(&cooling_cpufreq_lock);
>> + list_for_each_entry(cpufreq_device, &cpufreq_cooling_list, node)
>> + if (cpufreq_device->cool_dev == cdev)
>> + break;
>> + mutex_unlock(&cooling_cpufreq_lock);
>> + if (!cpufreq_device) {
>> + /* Cooling device pointer not found */
>> + return -EINVAL;
>> + }
>>
>> *state = cpufreq_device->cpufreq_state;
>>
>> @@ -406,7 +429,17 @@ 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)
>> {
>> - struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
>> + struct cpufreq_cooling_device *cpufreq_device = NULL;
>> +
>> + mutex_lock(&cooling_cpufreq_lock);
>> + list_for_each_entry(cpufreq_device, &cpufreq_cooling_list, node)
>> + if (cpufreq_device->cool_dev == cdev)
>> + break;
>> + mutex_unlock(&cooling_cpufreq_lock);
>> + if (!cpufreq_device) {
>> + /* Cooling device pointer not found */
>> + return -EINVAL;
>> + }
>>
>> return cpufreq_apply_cooling(cpufreq_device, state);
>> }
>> @@ -427,6 +460,7 @@ static struct notifier_block thermal_cpufreq_notifier_block = {
>> * __cpufreq_cooling_register - helper function to create cpufreq cooling device
>> * @np: a valid struct device_node to the cooling device device tree node
>> * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
>> + * @devdata: driver data pointer
>> *
>> * This interface function registers the cpufreq cooling device with the name
>> * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
>> @@ -438,7 +472,7 @@ static struct notifier_block thermal_cpufreq_notifier_block = {
>> */
>> static struct thermal_cooling_device *
>> __cpufreq_cooling_register(struct device_node *np,
>> - const struct cpumask *clip_cpus)
>> + const struct cpumask *clip_cpus, void *devdata)
>> {
>> struct thermal_cooling_device *cool_dev;
>> struct cpufreq_cooling_device *cpufreq_dev = NULL;
>> @@ -477,7 +511,7 @@ __cpufreq_cooling_register(struct device_node *np,
>> snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
>> cpufreq_dev->id);
>>
>> - cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
>> + cool_dev = thermal_of_cooling_device_register(np, dev_name, devdata,
>> &cpufreq_cooling_ops);
>> if (IS_ERR(cool_dev)) {
>> release_idr(&cpufreq_idr, cpufreq_dev->id);
>> @@ -489,10 +523,11 @@ __cpufreq_cooling_register(struct device_node *np,
>> mutex_lock(&cooling_cpufreq_lock);
>>
>> /* Register the notifier for first cpufreq cooling device */
>> - if (cpufreq_dev_count == 0)
>> + if (list_empty(&cpufreq_cooling_list))
>> cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
>> CPUFREQ_POLICY_NOTIFIER);
>> - cpufreq_dev_count++;
>> +
>> + list_add(&cpufreq_dev->node, &cpufreq_cooling_list);
>>
>> mutex_unlock(&cooling_cpufreq_lock);
>>
>> @@ -502,6 +537,7 @@ __cpufreq_cooling_register(struct device_node *np,
>> /**
>> * cpufreq_cooling_register - function to create cpufreq cooling device.
>> * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
>> + * @devdata: driver data pointer
>> *
>> * This interface function registers the cpufreq cooling device with the name
>> * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
>> @@ -511,9 +547,9 @@ __cpufreq_cooling_register(struct device_node *np,
>> * on failure, it returns a corresponding ERR_PTR().
>> */
>> struct thermal_cooling_device *
>> -cpufreq_cooling_register(const struct cpumask *clip_cpus)
>> +cpufreq_cooling_register(const struct cpumask *clip_cpus, void *devdata)
>> {
>> - return __cpufreq_cooling_register(NULL, clip_cpus);
>> + return __cpufreq_cooling_register(NULL, clip_cpus, devdata);
>> }
>> EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
>>
>> @@ -537,7 +573,7 @@ of_cpufreq_cooling_register(struct device_node *np,
>> if (!np)
>> return ERR_PTR(-EINVAL);
>>
>> - return __cpufreq_cooling_register(np, clip_cpus);
>> + return __cpufreq_cooling_register(np, clip_cpus, NULL);
>> }
>> EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
>>
>> @@ -554,17 +590,26 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
>> if (!cdev)
>> return;
>>
>> - cpufreq_dev = cdev->devdata;
>> mutex_lock(&cooling_cpufreq_lock);
>> - cpufreq_dev_count--;
>> +
>> + list_for_each_entry(cpufreq_dev, &cpufreq_cooling_list, node)
>> + if (cpufreq_dev->cool_dev == cdev)
>> + break;
>> +
>> + if (!cpufreq_dev) {
>> + /* Cooling device pointer not found */
>> + mutex_unlock(&cooling_cpufreq_lock);
>> + return;
>> + }
>
> Because you are adding several times the same code to search through
> your list of cdevs, I recommend adding at least a helper function to
> perform this recurring operation.
Good suggestion. will implement them in next version.
>
> Besides, are you sure you cannot keep both pointers, the cpufreq_dev and
> the driver devdata? One way is to embedded the driver devdata inside the
> cpufreq_dev and register cpufreq_dev. Then you would adapt the code to
> fetch each pointer accordingly. What do you think?
Yes I also thought of using some other ways but could not find.
Actually cpucooling layer is an intermediate
in between driver and thermal core layer. so ideally it should not
break any existing relation
between driver and thermal core layer even if cpucooling is used or not.
In one place in ACPI there is a check whether supplied driver data
matches with (struct thermal_cooling_device *)cdev->devdata.
so i had no option but to maintain cpufreq_dev in some local
structures and assign passed driver_data to cdev->devdata;
Also cpufreq_dev is a local cpucooling structures which should not be
exposed to user.
>
>> + thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
>> + list_del(&cpufreq_dev->node);
>>
>> /* Unregister the notifier for the last cpufreq cooling device */
>> - if (cpufreq_dev_count == 0)
>> + if (list_empty(&cpufreq_cooling_list))
>> 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);
>> kfree(cpufreq_dev);
>> }
>> diff --git a/drivers/thermal/db8500_cpufreq_cooling.c b/drivers/thermal/db8500_cpufreq_cooling.c
>> index 786d192..abb9bdd 100644
>> --- a/drivers/thermal/db8500_cpufreq_cooling.c
>> +++ b/drivers/thermal/db8500_cpufreq_cooling.c
>> @@ -35,7 +35,7 @@ static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)
>> return -EPROBE_DEFER;
>>
>> cpumask_set_cpu(0, &mask_val);
>> - cdev = cpufreq_cooling_register(&mask_val);
>> + cdev = cpufreq_cooling_register(&mask_val, NULL);
>>
>> if (IS_ERR(cdev)) {
>> dev_err(&pdev->dev, "Failed to register cooling device\n");
>> diff --git a/drivers/thermal/samsung/exynos_thermal_common.c b/drivers/thermal/samsung/exynos_thermal_common.c
>> index 3f5ad25..a7306fa 100644
>> --- a/drivers/thermal/samsung/exynos_thermal_common.c
>> +++ b/drivers/thermal/samsung/exynos_thermal_common.c
>> @@ -369,7 +369,7 @@ int exynos_register_thermal(struct thermal_sensor_conf *sensor_conf)
>> if (sensor_conf->cooling_data.freq_clip_count > 0) {
>> cpumask_set_cpu(0, &mask_val);
>> th_zone->cool_dev[th_zone->cool_dev_size] =
>> - cpufreq_cooling_register(&mask_val);
>> + cpufreq_cooling_register(&mask_val, NULL);
>> if (IS_ERR(th_zone->cool_dev[th_zone->cool_dev_size])) {
>> dev_err(sensor_conf->dev,
>> "Failed to register cpufreq cooling device\n");
>> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> index 9eec26d..7809db6 100644
>> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> @@ -409,7 +409,7 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
>> }
>>
>> /* Register cooling device */
>> - data->cool_dev = cpufreq_cooling_register(cpu_present_mask);
>> + data->cool_dev = cpufreq_cooling_register(cpu_present_mask, NULL);
>> if (IS_ERR(data->cool_dev)) {
>> dev_err(bgp->dev,
>> "Failed to register cpufreq cooling device\n");
>> diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h
>> index c303d38..aaef7d8 100644
>> --- a/include/linux/cpu_cooling.h
>> +++ b/include/linux/cpu_cooling.h
>> @@ -32,9 +32,10 @@
>> /**
>> * cpufreq_cooling_register - function to create cpufreq cooling device.
>> * @clip_cpus: cpumask of cpus where the frequency constraints will happen
>> + * @devdata: driver data pointer
>> */
>> struct thermal_cooling_device *
>> -cpufreq_cooling_register(const struct cpumask *clip_cpus);
>> +cpufreq_cooling_register(const struct cpumask *clip_cpus, void *devdata);
>>
>> /**
>> * of_cpufreq_cooling_register - create cpufreq cooling device based on DT.
>> @@ -63,7 +64,7 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev);
>> unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq);
>> #else /* !CONFIG_CPU_THERMAL */
>> static inline struct thermal_cooling_device *
>> -cpufreq_cooling_register(const struct cpumask *clip_cpus)
>> +cpufreq_cooling_register(const struct cpumask *clip_cpus, void *devdata)
>> {
>> return NULL;
>> }
>> --
>> 1.7.1
>>
>> --
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