Re: [PATCH v3 01/12] iommu/arm-smmu-v3: Put iopf enablement in the domain attach path

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Mar 12, 2025 at 11:10:34AM +0800, Baolu Lu wrote:
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 4aaf9b7bf862..a519854b3798 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2786,13 +2786,17 @@ static int arm_smmu_enable_iopf(struct
> arm_smmu_master *master,
>         return 0;
>  }
> 
> -static void arm_smmu_disable_iopf(struct arm_smmu_master *master)
> +static void arm_smmu_disable_iopf(struct arm_smmu_master *master,
> +                                 struct arm_smmu_master_domain
> *master_domain)
>  {
>         iommu_group_mutex_assert(master->dev);
> 
>         if (!IS_ENABLED(CONFIG_ARM_SMMU_V3_SVA))
>                 return;
> 
> +       if (!master_domain || !master_domain->using_iopf)
> +               return;
> +
>         master->iopf_refcount--;
>         if (master->iopf_refcount == 0)
>                 iopf_queue_remove_device(master->smmu->evtq.iopf,
> master->dev);
> @@ -2823,11 +2827,8 @@ static void arm_smmu_remove_master_domain(struct
> arm_smmu_master *master,
>         }
>         spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
> 
> -       if (master_domain) {
> -               if (master_domain->using_iopf)
> -                       arm_smmu_disable_iopf(master);
> -               kfree(master_domain);
> -       }
> +       arm_smmu_disable_iopf(master, master_domain);
> +       kfree(master_domain);
>  }
> 
>  /*
> @@ -2945,8 +2946,7 @@ int arm_smmu_attach_prepare(struct
> arm_smmu_attach_state *state,
>         return 0;
> 
>  err_iopf:
> -       if (master_domain && master_domain->using_iopf)
> -               arm_smmu_disable_iopf(master);
> +       arm_smmu_disable_iopf(master);
>  err_free_master_domain:
>         kfree(master_domain);
>         return ret;

Looks OK

Thanks,
Jason