Re: [PATCH v2 2/2] iommu/arm-smmu-v3: Adopt arm_smmu_event in handlers

[Nicolin Chen <nicolinc@nvidia.com>]

Hi Pranjal,

On Tue, Aug 27, 2024 at 12:30:26PM -0700, Pranjal Shrivastava wrote:

>         /* Stage-2 is always pinned at the moment */
> -       if (evt[1] & EVTQ_1_S2)
> +       if (event->stage)
>                 return -EFAULT;

Should it be named to "s2" v.s stage?

> -       mutex_lock(&smmu->streams_mutex);
> -       master = arm_smmu_find_master(smmu, sid);
> -       if (!master) {
> -               ret = -EINVAL;
> -               goto out_unlock;
> -       }
> +       if (!event->master)
> +               return -EINVAL;
> 
> -       ret = iommu_report_device_fault(master->dev, &fault_evt);
> -out_unlock:
> -       mutex_unlock(&smmu->streams_mutex);
> +       ret = iommu_report_device_fault(event->master->dev, &fault_evt);

The iommu_report_device_fault(master->dev) call lost its mutex
lock. I wonder if it could be unsafe to continue with that dev
pointer.

Nicolin