diff mbox series

[v2,linux-next] leds: powernv: replace of_node_put to __free

Message ID 20240529200233.1188228-1-marilene.agarcia@gmail.com (mailing list archive)
State Changes Requested
Headers show
Series [v2,linux-next] leds: powernv: replace of_node_put to __free | expand

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Commit Message

Marilene Andrade Garcia May 29, 2024, 8:02 p.m. UTC 
Use __free for device_node values, and thus drop calls to
of_node_put.

The variable attribute __free adds a scope based cleanup to
the device node. The goal is to reduce memory management issues
in the kernel code.

The of_node_put calls were removed, and the
for_each_available_child_of_node was replaced to the equivalent
for_each_available_child_of_node_scoped which use the __free.

Suggested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: MarileneGarcia <marilene.agarcia@gmail.com>
---
Changes v2:
It was missing a blank line.

Suggested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: MarileneGarcia <marilene.agarcia@gmail.com>
---
 drivers/leds/leds-powernv.c | 28 +++++++++-------------------
 1 file changed, 9 insertions(+), 19 deletions(-)

Comments

Lee Jones May 31, 2024, 4:44 p.m. UTC | #1 
On Wed, 29 May 2024, MarileneGarcia wrote:

> Use __free for device_node values, and thus drop calls to
> of_node_put.
> 
> The variable attribute __free adds a scope based cleanup to
> the device node. The goal is to reduce memory management issues
> in the kernel code.
> 
> The of_node_put calls were removed, and the
> for_each_available_child_of_node was replaced to the equivalent
> for_each_available_child_of_node_scoped which use the __free.
> 
> Suggested-by: Julia Lawall <julia.lawall@inria.fr>
> Signed-off-by: MarileneGarcia <marilene.agarcia@gmail.com>
> ---
> Changes v2:
> It was missing a blank line.
> 
> Suggested-by: Julia Lawall <julia.lawall@inria.fr>
> Signed-off-by: MarileneGarcia <marilene.agarcia@gmail.com>
> ---
>  drivers/leds/leds-powernv.c | 28 +++++++++-------------------
>  1 file changed, 9 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/leds/leds-powernv.c b/drivers/leds/leds-powernv.c
> index 4f01acb75727..8f94d2efed9f 100644
> --- a/drivers/leds/leds-powernv.c
> +++ b/drivers/leds/leds-powernv.c
> @@ -246,29 +246,25 @@ static int powernv_led_classdev(struct platform_device *pdev,
>  	const char *cur = NULL;
>  	int rc = -1;
>  	struct property *p;
> -	struct device_node *np;
>  	struct powernv_led_data *powernv_led;
>  	struct device *dev = &pdev->dev;
>  
> -	for_each_available_child_of_node(led_node, np) {
> +	for_each_available_child_of_node_scoped(led_node, np) {
>  		p = of_find_property(np, "led-types", NULL);
>  
>  		while ((cur = of_prop_next_string(p, cur)) != NULL) {
>  			powernv_led = devm_kzalloc(dev, sizeof(*powernv_led),
>  						   GFP_KERNEL);
> -			if (!powernv_led) {
> -				of_node_put(np);
> +			if (!powernv_led)
>  				return -ENOMEM;
> -			}
>  
>  			powernv_led->common = powernv_led_common;
>  			powernv_led->loc_code = (char *)np->name;
>  
>  			rc = powernv_led_create(dev, powernv_led, cur);
> -			if (rc) {
> -				of_node_put(np);
> +			if (rc)
>  				return rc;
> -			}
> +
>  		} /* while end */
>  	}
>  
> @@ -278,12 +274,11 @@ static int powernv_led_classdev(struct platform_device *pdev,
>  /* Platform driver probe */
>  static int powernv_led_probe(struct platform_device *pdev)
>  {
> -	struct device_node *led_node;
>  	struct powernv_led_common *powernv_led_common;
>  	struct device *dev = &pdev->dev;
> -	int rc;
> +	struct device_node *led_node __free(device_node) =
> +							of_find_node_by_path("/ibm,opal/leds");

This is not a good line-break strategy.

	struct device_node *led_node
		__free(device_node) = of_find_node_by_path("/ibm,opal/leds");

	struct device_node *led_node __free(device_node) =
		of_find_node_by_path("/ibm,opal/leds");

Please choose one of these instead.

I suggest the top one might read a little easier.

> -	led_node = of_find_node_by_path("/ibm,opal/leds");

Does the __free() have to be combined with an allocation?

>  	if (!led_node) {
>  		dev_err(dev, "%s: LED parent device node not found\n",
>  			__func__);
> @@ -292,20 +287,15 @@ static int powernv_led_probe(struct platform_device *pdev)
>  
>  	powernv_led_common = devm_kzalloc(dev, sizeof(*powernv_led_common),
>  					  GFP_KERNEL);
> -	if (!powernv_led_common) {
> -		rc = -ENOMEM;
> -		goto out;
> -	}
> +	if (!powernv_led_common)
> +		return -ENOMEM;
>  
>  	mutex_init(&powernv_led_common->lock);
>  	powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX);
>  
>  	platform_set_drvdata(pdev, powernv_led_common);
>  
> -	rc = powernv_led_classdev(pdev, led_node, powernv_led_common);
> -out:
> -	of_node_put(led_node);
> -	return rc;
> +	return powernv_led_classdev(pdev, led_node, powernv_led_common);
>  }
>  
>  /* Platform driver remove */
> -- 
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/leds/leds-powernv.c b/drivers/leds/leds-powernv.c
index 4f01acb75727..8f94d2efed9f 100644
--- a/drivers/leds/leds-powernv.c
+++ b/drivers/leds/leds-powernv.c
@@ -246,29 +246,25 @@  static int powernv_led_classdev(struct platform_device *pdev,
 	const char *cur = NULL;
 	int rc = -1;
 	struct property *p;
-	struct device_node *np;
 	struct powernv_led_data *powernv_led;
 	struct device *dev = &pdev->dev;
 
-	for_each_available_child_of_node(led_node, np) {
+	for_each_available_child_of_node_scoped(led_node, np) {
 		p = of_find_property(np, "led-types", NULL);
 
 		while ((cur = of_prop_next_string(p, cur)) != NULL) {
 			powernv_led = devm_kzalloc(dev, sizeof(*powernv_led),
 						   GFP_KERNEL);
-			if (!powernv_led) {
-				of_node_put(np);
+			if (!powernv_led)
 				return -ENOMEM;
-			}
 
 			powernv_led->common = powernv_led_common;
 			powernv_led->loc_code = (char *)np->name;
 
 			rc = powernv_led_create(dev, powernv_led, cur);
-			if (rc) {
-				of_node_put(np);
+			if (rc)
 				return rc;
-			}
+
 		} /* while end */
 	}
 
@@ -278,12 +274,11 @@  static int powernv_led_classdev(struct platform_device *pdev,
 /* Platform driver probe */
 static int powernv_led_probe(struct platform_device *pdev)
 {
-	struct device_node *led_node;
 	struct powernv_led_common *powernv_led_common;
 	struct device *dev = &pdev->dev;
-	int rc;
+	struct device_node *led_node __free(device_node) =
+							of_find_node_by_path("/ibm,opal/leds");
 
-	led_node = of_find_node_by_path("/ibm,opal/leds");
 	if (!led_node) {
 		dev_err(dev, "%s: LED parent device node not found\n",
 			__func__);
@@ -292,20 +287,15 @@  static int powernv_led_probe(struct platform_device *pdev)
 
 	powernv_led_common = devm_kzalloc(dev, sizeof(*powernv_led_common),
 					  GFP_KERNEL);
-	if (!powernv_led_common) {
-		rc = -ENOMEM;
-		goto out;
-	}
+	if (!powernv_led_common)
+		return -ENOMEM;
 
 	mutex_init(&powernv_led_common->lock);
 	powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX);
 
 	platform_set_drvdata(pdev, powernv_led_common);
 
-	rc = powernv_led_classdev(pdev, led_node, powernv_led_common);
-out:
-	of_node_put(led_node);
-	return rc;
+	return powernv_led_classdev(pdev, led_node, powernv_led_common);
 }
 
 /* Platform driver remove */