[PATCH v12 16/16] iommu: Make iommu_report_device_fault() return void

Lu Baolu
2024-02-07T01:40:26Z

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>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@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 | 25 +++++++--------------
4 files changed, 19 insertions(+), 34 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f632775414a5..7cc56cfe98dd 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1545,7 +1545,7 @@ 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
@@ -1583,10 +1583,9 @@ 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 89d290e8de5d..cf34e9eb2569 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -176,26 +176,22 @@ static struct iopf_group *iopf_group_alloc(struct iommu_fault_param *iopf_param,
* freed after the device has stopped generating page faults (or the iommu
* hardware has been set to block the page faults) and the pending page faults
* have been flushed.
- *
- * Return: 0 on success and <0 on error.
*/
-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 +203,21 @@ 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 +225,6 @@ 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