Re: [RFC PATCH 5/8] iommu/arm-smmu-v3: Add IRQ handle for smmu impl

[Pranjal Shrivastava <praan@google.com>]

On Mon, Jun 16, 2025 at 10:56:11AM +0800, Xueqi Zhang wrote:
> Add IRQ handle for smmu impl
> 
> Signed-off-by: Xueqi Zhang <xueqi.zhang@mediatek.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 ++++++++-
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 8 ++++++++
>  2 files changed, 16 insertions(+), 1 deletion(-)
> 
> 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 d36124a6bb54..154417b380fa 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -1954,7 +1954,8 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev)
>  			arm_smmu_decode_event(smmu, evt, &event);
>  			if (arm_smmu_handle_event(smmu, evt, &event))
>  				arm_smmu_dump_event(smmu, evt, &event, &rs);
> -
> +			if (smmu->impl && smmu->impl->smmu_evt_handler)
> +				smmu->impl->smmu_evt_handler(irq, smmu, evt, &rs);
>  			put_device(event.dev);
>  			cond_resched();
>  		}
> @@ -2091,7 +2092,13 @@ static irqreturn_t arm_smmu_combined_irq_thread(int irq, void *dev)
>  
>  static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>  {
> +	struct arm_smmu_device *smmu = dev;
> +
>  	arm_smmu_gerror_handler(irq, dev);
> +
> +	if (smmu->impl && smmu->impl->combined_irq_handle)
> +		smmu->impl->combined_irq_handle(irq, smmu);
> +
>  	return IRQ_WAKE_THREAD;
>  }
>  
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index 99eeb6143c49..f45c4bf84bc1 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -792,6 +792,7 @@ struct arm_smmu_device {
>  
>  	struct rb_root			streams;
>  	struct mutex			streams_mutex;
> +	const struct arm_smmu_v3_impl	*impl;
>  };
>  
>  struct arm_smmu_stream {
> @@ -998,6 +999,13 @@ int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
>  				struct arm_smmu_cmdq *cmdq, u64 *cmds, int n,
>  				bool sync);
>  
> +/* Implementation details */
> +struct arm_smmu_v3_impl {
> +	int (*combined_irq_handle)(int irq, struct arm_smmu_device *smmu_dev);
> +	int (*smmu_evt_handler)(int irq, struct arm_smmu_device *smmu_dev,
> +				u64 *evt, struct ratelimit_state *rs);
> +};

Let's add these to the exisiting struct arm_smmu_impl_ops and invoke
them like:

	if (smmu->impl && smmu->impl_ops->combined_irq_handle)
		smmu->impl_ops->combined_irq_handle(irq, smmu);

Or maybe we could merge the existing impl_dev and impl_ops into a single
structure.

> +
>  struct arm_smmu_device *arm_smmu_v3_impl_init(struct arm_smmu_device *smmu);
>  #if IS_ENABLED(CONFIG_ARM_SMMU_V3_MEDIATEK)
>  struct arm_smmu_device *arm_smmu_v3_impl_mtk_init(struct arm_smmu_device *smmu);
> -- 
> 2.46.0
> 
>