iommu/vt-d: Remove debugfs use of private data field

Since the page fault report and response have been tracked by ftrace, the
users can easily calculate the time used for a page fault handling. There's
no need to expose the similar functionality in debugfs. Hence, remove the
corresponding operations in debugfs.

Signed-off-by: Jingqi Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lu Baolu <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

Author: nuttyliu

drivers/iommu/intel/debugfs.c

@@ -706,7 +706,6 @@ static ssize_t dmar_perf_latency_write(struct file *filp,
 			dmar_latency_disable(iommu, DMAR_LATENCY_INV_IOTLB);
 			dmar_latency_disable(iommu, DMAR_LATENCY_INV_DEVTLB);
 			dmar_latency_disable(iommu, DMAR_LATENCY_INV_IEC);
-			dmar_latency_disable(iommu, DMAR_LATENCY_PRQ);
 		}
 		rcu_read_unlock();
 		break;
@@ -728,12 +727,6 @@ static ssize_t dmar_perf_latency_write(struct file *filp,
 			dmar_latency_enable(iommu, DMAR_LATENCY_INV_IEC);
 		rcu_read_unlock();
 		break;
-	case 4:
-		rcu_read_lock();
-		for_each_active_iommu(iommu, drhd)
-			dmar_latency_enable(iommu, DMAR_LATENCY_PRQ);
-		rcu_read_unlock();
-		break;
 	default:
 		return -EINVAL;
 	}

drivers/iommu/intel/perf.h

@@ -11,7 +11,6 @@ enum latency_type {
 	DMAR_LATENCY_INV_IOTLB = 0,
 	DMAR_LATENCY_INV_DEVTLB,
 	DMAR_LATENCY_INV_IEC,
-	DMAR_LATENCY_PRQ,
 	DMAR_LATENCY_NUM
 };
 

drivers/iommu/intel/svm.c

@@ -583,12 +583,6 @@ static void intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
 		event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
 		event.fault.prm.private_data[0] = desc->priv_data[0];
 		event.fault.prm.private_data[1] = desc->priv_data[1];
-	} else if (dmar_latency_enabled(iommu, DMAR_LATENCY_PRQ)) {
-		/*
-		 * If the private data fields are not used by hardware, use it
-		 * to monitor the prq handle latency.
-		 */
-		event.fault.prm.private_data[0] = ktime_to_ns(ktime_get());
 	}
 
 	iommu_report_device_fault(dev, &event);
@@ -768,9 +762,6 @@ void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
 		if (private_present) {
 			desc.qw2 = prm->private_data[0];
 			desc.qw3 = prm->private_data[1];
-		} else if (prm->private_data[0]) {
-			dmar_latency_update(iommu, DMAR_LATENCY_PRQ,
-				ktime_to_ns(ktime_get()) - prm->private_data[0]);
 		}
 
 		qi_submit_sync(iommu, &desc, 1, 0);