Commit 0f4834ab authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu/vt-d: Add PRQ handling latency sampling 



The execution time for page fault request handling is performance critical
and needs to be monitored. This adds code to sample the execution time of
page fault request handling.

Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210610020115.1637656-17-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 74eb87a0

drivers/iommu/intel/svm.c

+13 −3
Original line number Original line Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <trace/events/intel_iommu.h>

#include <trace/events/intel_iommu.h>





#include "pasid.h"

#include "pasid.h"

#include "perf.h"

#include "../iommu-sva-lib.h"

#include "../iommu-sva-lib.h"





static irqreturn_t prq_event_thread(int irq, void *d);

static irqreturn_t prq_event_thread(int irq, void *d);
@@ -838,8 +839,8 @@ static int prq_to_iommu_prot(struct page_req_dsc *req) 
	return prot;

	return prot;

}

}





static int

static int intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,

intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc)

				struct page_req_dsc *desc)

{

{

	struct iommu_fault_event event;

	struct iommu_fault_event event;
@@ -871,6 +872,12 @@ intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc) 
		event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;

		event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;

		memcpy(event.fault.prm.private_data, desc->priv_data,

		memcpy(event.fault.prm.private_data, desc->priv_data,

		       sizeof(desc->priv_data));

		       sizeof(desc->priv_data));

	} 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());

	}

	}





	return iommu_report_device_fault(dev, &event);

	return iommu_report_device_fault(dev, &event);
@@ -983,7 +990,7 @@ static irqreturn_t prq_event_thread(int irq, void *d) 
		 * If prq is to be handled outside iommu driver via receiver of

		 * If prq is to be handled outside iommu driver via receiver of

		 * the fault notifiers, we skip the page response here.

		 * the fault notifiers, we skip the page response here.

		 */

		 */

		if (intel_svm_prq_report(sdev->dev, req))

		if (intel_svm_prq_report(iommu, sdev->dev, req))

			handle_bad_prq_event(iommu, req, QI_RESP_INVALID);

			handle_bad_prq_event(iommu, req, QI_RESP_INVALID);





		trace_prq_report(iommu, sdev->dev, req->qw_0, req->qw_1,

		trace_prq_report(iommu, sdev->dev, req->qw_0, req->qw_1,
@@ -1172,6 +1179,9 @@ int intel_svm_page_response(struct device *dev, 
		if (private_present)

		if (private_present)

			memcpy(&desc.qw2, prm->private_data,

			memcpy(&desc.qw2, prm->private_data,

			       sizeof(prm->private_data));

			       sizeof(prm->private_data));

		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);

		qi_submit_sync(iommu, &desc, 1, 0);

	}

	}