Re: [PATCH net-next 1/8] net: ipa: maintain bitmap of suspend-enabled endpoints

[Bryan O'Donoghue]

On 18/04/2024 21:47, Alex Elder wrote:
> Keep track of which endpoints have the SUSPEND IPA interrupt enabled
> in a variable-length bitmap.  This will be used in the next patch to
> allow the SUSPEND interrupt type to be disabled except when needed.
>
> Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
> ---
>   drivers/net/ipa/ipa_interrupt.c | 19 +++++++++++++++++--
>   1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ipa/ipa_interrupt.c b/drivers/net/ipa/ipa_interrupt.c
> index c44ec05f71e6f..0e8d4e43275ea 100644
> --- a/drivers/net/ipa/ipa_interrupt.c
> +++ b/drivers/net/ipa/ipa_interrupt.c
> @@ -37,11 +37,13 @@
>    * @ipa:		IPA pointer
>    * @irq:		Linux IRQ number used for IPA interrupts
>    * @enabled:		Mask indicating which interrupts are enabled
> + * @suspend_enabled:	Bitmap of endpoints with the SUSPEND interrupt enabled
>    */
>   struct ipa_interrupt {
>   	struct ipa *ipa;
>   	u32 irq;
>   	u32 enabled;
> +	unsigned long *suspend_enabled;
>   };
>   
>   /* Clear the suspend interrupt for all endpoints that signaled it */
> @@ -211,6 +213,7 @@ static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
>   		val |= mask;
>   	else
>   		val &= ~mask;
> +	__change_bit(endpoint_id, interrupt->suspend_enabled);
>   
>   	iowrite32(val, ipa->reg_virt + offset);
>   }
> @@ -246,7 +249,16 @@ int ipa_interrupt_config(struct ipa *ipa)
>   
>   	interrupt->ipa = ipa;
>   
> -	/* Disable all IPA interrupt types */
> +	/* Initially all IPA interrupt types are disabled */
> +	interrupt->enabled = 0;
> +	interrupt->suspend_enabled = bitmap_zalloc(ipa->endpoint_count,
> +						   GFP_KERNEL);

why not use devm_bitmap_zalloc() instead and skip managing the cleanup ?

> +	if (!interrupt->suspend_enabled) {
> +		ret = -ENOMEM;
> +		goto err_kfree;
> +	}
> +
> +	/* Disable IPA interrupt types */
>   	reg = ipa_reg(ipa, IPA_IRQ_EN);
>   	iowrite32(0, ipa->reg_virt + reg_offset(reg));
>   
> @@ -254,7 +266,7 @@ int ipa_interrupt_config(struct ipa *ipa)
>   				   "ipa", interrupt);
>   	if (ret) {
>   		dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
> -		goto err_kfree;
> +		goto err_free_bitmap;
>   	}
>   
>   	ret = dev_pm_set_wake_irq(dev, irq);
> @@ -270,6 +282,8 @@ int ipa_interrupt_config(struct ipa *ipa)
>   
>   err_free_irq:
>   	free_irq(interrupt->irq, interrupt);
> +err_free_bitmap:
> +	bitmap_free(interrupt->suspend_enabled);
>   err_kfree:
>   	kfree(interrupt);

You could also use devm_kzalloc() and do away with the kfree()s you have 
here on the probe path.

>   
> @@ -286,6 +300,7 @@ void ipa_interrupt_deconfig(struct ipa *ipa)
>   
>   	dev_pm_clear_wake_irq(dev);
>   	free_irq(interrupt->irq, interrupt);
> +	bitmap_free(interrupt->suspend_enabled);
>   }
>   
>   /* Initialize the IPA interrupt structure */

Just suggestions though.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>