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

Joel Granados
2024-01-25T16:26:27Z

[-- Attachment #1: Type: text/plain, Size: 6815 bytes --]

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?

> -int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
> +void iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
> {
> struct iommu_fault *fault = &evt->fault;
> struct iommu_fault_param *iopf_param;
> struct iopf_group abort_group = {};
> struct iopf_group *group;
> - int ret;
>
> iopf_param = iopf_get_dev_fault_param(dev);
> if (WARN_ON(!iopf_param))
> - return -ENODEV;
> + return;
>
> if (!(fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) {
> - ret = report_partial_fault(iopf_param, fault);
> + report_partial_fault(iopf_param, fault);
> iopf_put_dev_fault_param(iopf_param);
> /* A request that is not the last does not need to be ack'd */
> - return ret;
> }
>
> /*
> @@ -207,25 +205,21 @@ int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
> * leaving, otherwise partial faults will be stuck.
> */
> group = iopf_group_alloc(iopf_param, evt, &abort_group);
> - if (group == &abort_group) {
> - ret = -ENOMEM;
> + if (group == &abort_group)
> goto err_abort;
> - }
>
> group->domain = get_domain_for_iopf(dev, fault);
> - if (!group->domain) {
> - ret = -EINVAL;
> + if (!group->domain)
> goto err_abort;
> - }
>
> /*
> * On success iopf_handler must call iopf_group_response() and
> * iopf_free_group()
> */
> - ret = group->domain->iopf_handler(group);
> - if (ret)
> + if (group->domain->iopf_handler(group))
> goto err_abort;
> - return 0;
> +
> + return;
>
> err_abort:
> iopf_group_response(group, IOMMU_PAGE_RESP_FAILURE);
> @@ -233,7 +227,6 @@ int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
> __iopf_free_group(group);
> else
> iopf_free_group(group);
> - return ret;
> }
> EXPORT_SYMBOL_GPL(iommu_report_device_fault);
>
> --
> 2.34.1
>

--

Joel Granados

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 659 bytes --]