Re: [PATCH v2 2/4] hwspinlock: qcom: implement bust operation

[Bjorn Andersson]

On Fri, May 24, 2024 at 06:26:41PM -0700, Chris Lew wrote:
> From: Richard Maina <quic_rmaina@xxxxxxxxxxx>
> 
> Implement a new operation qcom_hwspinlock_bust() which can be invoked
> to bust any locks that are in use when a remoteproc is stopped or
> crashed.
> 
> Signed-off-by: Richard Maina <quic_rmaina@xxxxxxxxxxx>
> Signed-off-by: Chris Lew <quic_clew@xxxxxxxxxxx>

Reviewed-by: Bjorn Andersson <andersson@xxxxxxxxxx>

Regards,
Bjorn

> ---
>  drivers/hwspinlock/qcom_hwspinlock.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c
> index 814dfe8697bf..0390979fd765 100644
> --- a/drivers/hwspinlock/qcom_hwspinlock.c
> +++ b/drivers/hwspinlock/qcom_hwspinlock.c
> @@ -64,9 +64,34 @@ static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
>  		pr_err("%s: failed to unlock spinlock\n", __func__);
>  }
>  
> +static int qcom_hwspinlock_bust(struct hwspinlock *lock, unsigned int id)
> +{
> +	struct regmap_field *field = lock->priv;
> +	u32 owner;
> +	int ret;
> +
> +	ret = regmap_field_read(field, &owner);
> +	if (ret) {
> +		dev_err(lock->bank->dev, "unable to query spinlock owner\n");
> +		return ret;
> +	}
> +
> +	if (owner != id)
> +		return 0;
> +
> +	ret = regmap_field_write(field, 0);
> +	if (ret) {
> +		dev_err(lock->bank->dev, "failed to bust spinlock\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static const struct hwspinlock_ops qcom_hwspinlock_ops = {
>  	.trylock	= qcom_hwspinlock_trylock,
>  	.unlock		= qcom_hwspinlock_unlock,
> +	.bust		= qcom_hwspinlock_bust,
>  };
>  
>  static const struct regmap_config sfpb_mutex_config = {
> 
> -- 
> 2.25.1
>