[RFC PATCH 2/5] iommu/vt-d: Initialize a PASID consumer

[Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

This adds the Intel vt-d specific ops to initialize a PASID
consumer.

Cc: Ashok Raj <ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: Kevin Tian <kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Liu Yi L <yi.l.liu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/iommu/intel-iommu.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 49a278a699b0..769b7059d52f 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5597,6 +5597,35 @@ static int intel_iommu_domain_get_attr(struct iommu_domain *domain,
 	return ret;
 }
 
+static int intel_iommu_pasid_init(struct iommu_pasid *pasid)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu = NULL, *temp;
+
+	/*
+	 *  Iterate the iommu units and get a scalable mode capable one
+	 *  for virtual command usages. Return failure if scalable mode
+	 *  doesn't support by any unit.
+	 */
+	rcu_read_lock();
+	for_each_active_iommu(temp, drhd) {
+		if (sm_supported(temp)) {
+			iommu = temp;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	if (!iommu)
+		return -ENODEV;
+
+	pasid->max = intel_pasid_max_id;
+	pasid->min = PASID_MIN;
+	pasid->priv = iommu;
+
+	return 0;
+}
+
 const struct iommu_ops intel_iommu_ops = {
 	.capable		= intel_iommu_capable,
 	.domain_alloc		= intel_iommu_domain_alloc,
@@ -5616,6 +5645,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.domain_get_attr	= intel_iommu_domain_get_attr,
 	.get_dev_attr		= intel_iommu_get_dev_attr,
 	.set_dev_attr		= intel_iommu_set_dev_attr,
+	.pasid_init		= intel_iommu_pasid_init,
 	.pgsize_bitmap		= INTEL_IOMMU_PGSIZES,
 };
 
-- 
2.17.1