Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1681627 > unrolled thread

Re: [PATCH] bus: arm-cci: constify attribute_group structures.

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH] bus: arm-cci: constify attribute_group structures. Suzuki K Poulose <Suzuki.Poulose@arm.com> - 2017-07-05 18:10 +0200
    Re: [PATCH] bus: arm-cci: constify attribute_group structures. Arvind Yadav <arvind.yadav.cs@gmail.com> - 2017-07-06 07:00 +0200
      Re: [PATCH] bus: arm-cci: constify attribute_group structures. Suzuki K Poulose <Suzuki.Poulose@arm.com> - 2017-07-06 10:50 +0200

#1681627 — Re: [PATCH] bus: arm-cci: constify attribute_group structures.

On 03/07/17 08:46, Arvind Yadav wrote:
> attribute_groups are not supposed to change at runtime. All functions
> working with attribute_groups provided by <linux/sysfs.h> work with const
> attribute_group. So mark the non-const structs as const.
>
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
> ---
>  drivers/bus/arm-cci.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
> index c49da15..64c75d2 100644
> --- a/drivers/bus/arm-cci.c
> +++ b/drivers/bus/arm-cci.c
> @@ -1445,16 +1445,16 @@ static ssize_t pmu_cpumask_attr_show(struct device *dev,
>  	NULL,
>  };
>
> -static struct attribute_group pmu_attr_group = {
> +static const struct attribute_group pmu_attr_group = {
>  	.attrs = pmu_attrs,
>  };
>
> -static struct attribute_group pmu_format_attr_group = {
> +static const struct attribute_group pmu_format_attr_group = {
>  	.name = "format",
>  	.attrs = NULL,		/* Filled in cci_pmu_init_attrs */
>  };



>
> -static struct attribute_group pmu_event_attr_group = {
> +static const struct attribute_group pmu_event_attr_group = {
>  	.name = "events",
>  	.attrs = NULL,		/* Filled in cci_pmu_init_attrs */
>  };
>

I think we cannot make these const, as the attrs field gets filled in at runtime, indicated
by the comments next to them.

Cheers
Suzuki

[toc] | [next] | [standalone]

#1682042

Hi,


On Wednesday 05 July 2017 09:33 PM, Suzuki K Poulose wrote:
> On 03/07/17 08:46, Arvind Yadav wrote:
>> attribute_groups are not supposed to change at runtime. All functions
>> working with attribute_groups provided by <linux/sysfs.h> work with 
>> const
>> attribute_group. So mark the non-const structs as const.
>>
>> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
>> ---
>>  drivers/bus/arm-cci.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
>> index c49da15..64c75d2 100644
>> --- a/drivers/bus/arm-cci.c
>> +++ b/drivers/bus/arm-cci.c
>> @@ -1445,16 +1445,16 @@ static ssize_t pmu_cpumask_attr_show(struct 
>> device *dev,
>>      NULL,
>>  };
>>
>> -static struct attribute_group pmu_attr_group = {
>> +static const struct attribute_group pmu_attr_group = {
>>      .attrs = pmu_attrs, /*This can be const*/
>>  };
>>
>> -static struct attribute_group pmu_format_attr_group = {
>> +static const struct attribute_group pmu_format_attr_group = {
>>      .name = "format",
>>      .attrs = NULL,        /* Filled in cci_pmu_init_attrs */
>>  };
>
>
>
>>
>> -static struct attribute_group pmu_event_attr_group = {
>> +static const struct attribute_group pmu_event_attr_group = {
>>      .name = "events",
>>      .attrs = NULL,        /* Filled in cci_pmu_init_attrs */
>>  };
>>
>
> I think we cannot make these const, as the attrs field gets filled in 
> at runtime, indicated
> by the comments next to them.
>
     Yes, Your are right. It's filled at run time.
         pmu_event_attr_group.attrs = model->event_attrs;
         pmu_format_attr_group.attrs = model->format_attrs;
     can we make pmu_attr_group as const.? It's already initialized.
     If you are ok with this please let me know. I can push updated patch.


> Cheers
> Suzuki
>
Thanks,
Arvind Yadav

[toc] | [prev] | [next] | [standalone]

#1682196

On 06/07/17 05:53, Arvind Yadav wrote:
> Hi,
>
>
> On Wednesday 05 July 2017 09:33 PM, Suzuki K Poulose wrote:
>> On 03/07/17 08:46, Arvind Yadav wrote:
>>> attribute_groups are not supposed to change at runtime. All functions
>>> working with attribute_groups provided by <linux/sysfs.h> work with const
>>> attribute_group. So mark the non-const structs as const.
>>>
>>> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
>>> ---
>>>  drivers/bus/arm-cci.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
>>> index c49da15..64c75d2 100644
>>> --- a/drivers/bus/arm-cci.c
>>> +++ b/drivers/bus/arm-cci.c
>>> @@ -1445,16 +1445,16 @@ static ssize_t pmu_cpumask_attr_show(struct device *dev,
>>>      NULL,
>>>  };
>>>
>>> -static struct attribute_group pmu_attr_group = {
>>> +static const struct attribute_group pmu_attr_group = {
>>>      .attrs = pmu_attrs, /*This can be const*/
>>>  };
>>>
>>> -static struct attribute_group pmu_format_attr_group = {
>>> +static const struct attribute_group pmu_format_attr_group = {
>>>      .name = "format",
>>>      .attrs = NULL,        /* Filled in cci_pmu_init_attrs */
>>>  };
>>
>>
>>
>>>
>>> -static struct attribute_group pmu_event_attr_group = {
>>> +static const struct attribute_group pmu_event_attr_group = {
>>>      .name = "events",
>>>      .attrs = NULL,        /* Filled in cci_pmu_init_attrs */
>>>  };
>>>
>>
>> I think we cannot make these const, as the attrs field gets filled in at runtime, indicated
>> by the comments next to them.
>>
>     Yes, Your are right. It's filled at run time.
>         pmu_event_attr_group.attrs = model->event_attrs;
>         pmu_format_attr_group.attrs = model->format_attrs;
>     can we make pmu_attr_group as const.? It's already initialized.
>     If you are ok with this please let me know. I can push updated patch.
>

Yes, you can do that.

Or you could go a step ahead and create per-model pmu_attr_groups[], with shared
pmu_attr_group and per-model event/format groups and tie it to the model description
and make everything const.

i.e,

static const struct attribute_group cci5xx_pmu_attr_groups[] = {
	&pmu_attr_group,
	&cci5xx_format_attr_group,
	&cci5xx_event_attr_group,
	NULL,
};

static const struct attribute_group cci400r0_pmu_attr_groups = {
	&pmu_attr_group,
	&cci400_pmu_format_attr_group,
	&cci400_pmu_event_attr_group,
	NULL,
};

static const struct attribute_group cci400r1_pmu_attr_groups = {
	&pmu_attr_group,
	&cci400_pmu_format_attr_group,
	&cci400r1_pmu_event_attr_group,
	NULL,
};

and then do :

cci_pmu->pmu = (struct pmu) {
	....
	.attr_groups = model->attr_groups,
};

Suzuki

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web