[v1] Add support for binding ACPI platform profile to multiple drivers

[PATCH 5/8] ACPI: platform_profile: Use guard(mutex) for register/unregister

Posted by Mario Limonciello 1 year, 3 months ago

guard(mutex) can be used to automatically release mutexes when going
out of scope.

Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/acpi/platform_profile.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index 0c60fc970b6e8..81928adccfade 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -180,41 +180,34 @@ int platform_profile_register(struct platform_profile_handler *pprof)
 {
 	int err;
 
-	mutex_lock(&profile_lock);
+	guard(mutex)(&profile_lock);
 	/* We can only have one active profile */
-	if (cur_profile) {
-		mutex_unlock(&profile_lock);
+	if (cur_profile)
 		return -EEXIST;
-	}
 
 	/* Sanity check the profile handler field are set */
 	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
-		!pprof->profile_set || !pprof->profile_get) {
-		mutex_unlock(&profile_lock);
+		!pprof->profile_set || !pprof->profile_get)
 		return -EINVAL;
-	}
 
 	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
-	if (err) {
-		mutex_unlock(&profile_lock);
+	if (err)
 		return err;
-	}
 	list_add_tail(&pprof->list, &platform_profile_handler_list);
 
 	cur_profile = pprof;
-	mutex_unlock(&profile_lock);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(platform_profile_register);
 
 int platform_profile_remove(struct platform_profile_handler *pprof)
 {
+	guard(mutex)(&profile_lock);
+
 	list_del(&pprof->list);
 
 	sysfs_remove_group(acpi_kobj, &platform_profile_group);
-	mutex_lock(&profile_lock);
 	cur_profile = NULL;
-	mutex_unlock(&profile_lock);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(platform_profile_remove);
-- 
2.43.0

Re: [PATCH 5/8] ACPI: platform_profile: Use guard(mutex) for register/unregister

Posted by Ilpo Järvinen 1 year, 3 months ago

On Fri, 25 Oct 2024, Mario Limonciello wrote:

> guard(mutex) can be used to automatically release mutexes when going
> out of scope.
> 
> Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/acpi/platform_profile.c | 19 ++++++-------------
>  1 file changed, 6 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index 0c60fc970b6e8..81928adccfade 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -180,41 +180,34 @@ int platform_profile_register(struct platform_profile_handler *pprof)
>  {
>  	int err;
>  
> -	mutex_lock(&profile_lock);
> +	guard(mutex)(&profile_lock);
>  	/* We can only have one active profile */
> -	if (cur_profile) {
> -		mutex_unlock(&profile_lock);
> +	if (cur_profile)
>  		return -EEXIST;
> -	}
>  
>  	/* Sanity check the profile handler field are set */
>  	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
> -		!pprof->profile_set || !pprof->profile_get) {
> -		mutex_unlock(&profile_lock);
> +		!pprof->profile_set || !pprof->profile_get)

Could you please also correct the misleading indentation here while 
touching the line.

>  		return -EINVAL;
> -	}
>  
>  	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
> -	if (err) {
> -		mutex_unlock(&profile_lock);
> +	if (err)
>  		return err;
> -	}
>  	list_add_tail(&pprof->list, &platform_profile_handler_list);
>  
>  	cur_profile = pprof;
> -	mutex_unlock(&profile_lock);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_register);
>  
>  int platform_profile_remove(struct platform_profile_handler *pprof)
>  {
> +	guard(mutex)(&profile_lock);
> +
>  	list_del(&pprof->list);
>  
>  	sysfs_remove_group(acpi_kobj, &platform_profile_group);
> -	mutex_lock(&profile_lock);

Now this something I don't want to sneak in with a transformation change 
like this. What is a clear extension of the critical section should be in 
own patch with proper justification given.

If that was not intentional, you can sill place guard() where the original 
mutex_lock() was, it doesn't have to be on the first line of a function.

>  	cur_profile = NULL;
> -	mutex_unlock(&profile_lock);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_remove);
> 

-- 
 i.

Re: [PATCH 5/8] ACPI: platform_profile: Use guard(mutex) for register/unregister

Posted by Mark Pearson 1 year, 3 months ago


On Fri, Oct 25, 2024, at 3:30 PM, Mario Limonciello wrote:
> guard(mutex) can be used to automatically release mutexes when going
> out of scope.
>
> Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/acpi/platform_profile.c | 19 ++++++-------------
>  1 file changed, 6 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/acpi/platform_profile.c 
> b/drivers/acpi/platform_profile.c
> index 0c60fc970b6e8..81928adccfade 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -180,41 +180,34 @@ int platform_profile_register(struct 
> platform_profile_handler *pprof)
>  {
>  	int err;
> 
> -	mutex_lock(&profile_lock);
> +	guard(mutex)(&profile_lock);
>  	/* We can only have one active profile */
> -	if (cur_profile) {
> -		mutex_unlock(&profile_lock);
> +	if (cur_profile)
>  		return -EEXIST;
> -	}
> 
>  	/* Sanity check the profile handler field are set */
>  	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
> -		!pprof->profile_set || !pprof->profile_get) {
> -		mutex_unlock(&profile_lock);
> +		!pprof->profile_set || !pprof->profile_get)
>  		return -EINVAL;
> -	}
> 
>  	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
> -	if (err) {
> -		mutex_unlock(&profile_lock);
> +	if (err)
>  		return err;
> -	}
>  	list_add_tail(&pprof->list, &platform_profile_handler_list);
> 
>  	cur_profile = pprof;
> -	mutex_unlock(&profile_lock);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_register);
> 
>  int platform_profile_remove(struct platform_profile_handler *pprof)
>  {
> +	guard(mutex)(&profile_lock);
> +
>  	list_del(&pprof->list);
> 
>  	sysfs_remove_group(acpi_kobj, &platform_profile_group);
> -	mutex_lock(&profile_lock);
>  	cur_profile = NULL;
> -	mutex_unlock(&profile_lock);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_remove);
> -- 
> 2.43.0

Looks good to me.
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>

Mark

Re: [PATCH 5/8] ACPI: platform_profile: Use guard(mutex) for register/unregister

Posted by Hans de Goede 1 year, 3 months ago

Hi,

On 25-Oct-24 9:30 PM, Mario Limonciello wrote:
> guard(mutex) can be used to automatically release mutexes when going
> out of scope.
> 
> Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans



> ---
>  drivers/acpi/platform_profile.c | 19 ++++++-------------
>  1 file changed, 6 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index 0c60fc970b6e8..81928adccfade 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -180,41 +180,34 @@ int platform_profile_register(struct platform_profile_handler *pprof)
>  {
>  	int err;
>  
> -	mutex_lock(&profile_lock);
> +	guard(mutex)(&profile_lock);
>  	/* We can only have one active profile */
> -	if (cur_profile) {
> -		mutex_unlock(&profile_lock);
> +	if (cur_profile)
>  		return -EEXIST;
> -	}
>  
>  	/* Sanity check the profile handler field are set */
>  	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
> -		!pprof->profile_set || !pprof->profile_get) {
> -		mutex_unlock(&profile_lock);
> +		!pprof->profile_set || !pprof->profile_get)
>  		return -EINVAL;
> -	}
>  
>  	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
> -	if (err) {
> -		mutex_unlock(&profile_lock);
> +	if (err)
>  		return err;
> -	}
>  	list_add_tail(&pprof->list, &platform_profile_handler_list);
>  
>  	cur_profile = pprof;
> -	mutex_unlock(&profile_lock);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_register);
>  
>  int platform_profile_remove(struct platform_profile_handler *pprof)
>  {
> +	guard(mutex)(&profile_lock);
> +
>  	list_del(&pprof->list);
>  
>  	sysfs_remove_group(acpi_kobj, &platform_profile_group);
> -	mutex_lock(&profile_lock);
>  	cur_profile = NULL;
> -	mutex_unlock(&profile_lock);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_remove);