Re: [PATCH v10 16/16] iommu: Make iommu_report_device_fault() reutrn void

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2024/1/26 0:26, Joel Granados wrote:
> On Mon, Jan 22, 2024 at 01:43:08PM +0800, Lu Baolu wrote:
>> As the iommu_report_device_fault() has been converted to auto-respond a
>> page fault if it fails to enqueue it, there's no need to return a code
>> in any case. Make it return void.
>>
>> Suggested-by: Jason Gunthorpe<jgg@nvidia.com>
>> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>
>> ---
>>   include/linux/iommu.h                       |  5 ++---
>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  4 ++--
>>   drivers/iommu/intel/svm.c                   | 19 +++++++----------
>>   drivers/iommu/io-pgfault.c                  | 23 +++++++--------------
>>   4 files changed, 19 insertions(+), 32 deletions(-)
>>
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index d7b6f4017254..1ccad10e8164 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -1549,7 +1549,7 @@ struct iopf_queue *iopf_queue_alloc(const char *name);
>>   void iopf_queue_free(struct iopf_queue *queue);
>>   int iopf_queue_discard_partial(struct iopf_queue *queue);
>>   void iopf_free_group(struct iopf_group *group);
>> -int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt);
>> +void iommu_report_device_fault(struct device *dev, struct iopf_fault *evt);
>>   void iopf_group_response(struct iopf_group *group,
>>   			 enum iommu_page_response_code status);
>>   #else
>> @@ -1587,10 +1587,9 @@ static inline void iopf_free_group(struct iopf_group *group)
>>   {
>>   }
>>   
>> -static inline int
>> +static inline void
>>   iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
>>   {
>> -	return -ENODEV;
>>   }
>>   
>>   static inline void iopf_group_response(struct iopf_group *group,
>> 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 42eb59cb99f4..02580364acda 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> @@ -1455,7 +1455,7 @@ arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid)
>>   /* IRQ and event handlers */
>>   static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
>>   {
>> -	int ret;
>> +	int ret = 0;
>>   	u32 perm = 0;
>>   	struct arm_smmu_master *master;
>>   	bool ssid_valid = evt[0] & EVTQ_0_SSV;
>> @@ -1511,7 +1511,7 @@ static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
>>   		goto out_unlock;
>>   	}
>>   
>> -	ret = iommu_report_device_fault(master->dev, &fault_evt);
>> +	iommu_report_device_fault(master->dev, &fault_evt);
>>   out_unlock:
>>   	mutex_unlock(&smmu->streams_mutex);
>>   	return ret;
>> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
>> index 2f8716636dbb..b644d57da841 100644
>> --- a/drivers/iommu/intel/svm.c
>> +++ b/drivers/iommu/intel/svm.c
>> @@ -561,14 +561,11 @@ static int prq_to_iommu_prot(struct page_req_dsc *req)
>>   	return prot;
>>   }
>>   
>> -static int intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
>> -				struct page_req_dsc *desc)
>> +static void intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
>> +				 struct page_req_dsc *desc)
>>   {
>>   	struct iopf_fault event = { };
>>   
>> -	if (!dev || !dev_is_pci(dev))
>> -		return -ENODEV;
>> -
>>   	/* Fill in event data for device specific processing */
>>   	event.fault.type = IOMMU_FAULT_PAGE_REQ;
>>   	event.fault.prm.addr = (u64)desc->addr << VTD_PAGE_SHIFT;
>> @@ -601,7 +598,7 @@ static int intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
>>   		event.fault.prm.private_data[0] = ktime_to_ns(ktime_get());
>>   	}
>>   
>> -	return iommu_report_device_fault(dev, &event);
>> +	iommu_report_device_fault(dev, &event);
>>   }
>>   
>>   static void handle_bad_prq_event(struct intel_iommu *iommu,
>> @@ -704,12 +701,10 @@ static irqreturn_t prq_event_thread(int irq, void *d)
>>   		if (!pdev)
>>   			goto bad_req;
>>   
>> -		if (intel_svm_prq_report(iommu, &pdev->dev, req))
>> -			handle_bad_prq_event(iommu, req, QI_RESP_INVALID);
>> -		else
>> -			trace_prq_report(iommu, &pdev->dev, req->qw_0, req->qw_1,
>> -					 req->priv_data[0], req->priv_data[1],
>> -					 iommu->prq_seq_number++);
>> +		intel_svm_prq_report(iommu, &pdev->dev, req);
>> +		trace_prq_report(iommu, &pdev->dev, req->qw_0, req->qw_1,
>> +				 req->priv_data[0], req->priv_data[1],
>> +				 iommu->prq_seq_number++);
>>   		pci_dev_put(pdev);
>>   prq_advance:
>>   		head = (head + sizeof(*req)) & PRQ_RING_MASK;
>> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
>> index 6e63e5a02884..b64229dab976 100644
>> --- a/drivers/iommu/io-pgfault.c
>> +++ b/drivers/iommu/io-pgfault.c
>> @@ -179,23 +179,21 @@ static struct iopf_group *iopf_group_alloc(struct iommu_fault_param *iopf_param,
>>    *
>>    * Return: 0 on success and <0 on error.
>>    */
> Should you remove the documentation that describes the return also?

Yes. Will do.

Best regards,
baolu