1 files changed, 50 insertions, 4 deletions

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 1aa823974cda..0eb1c827a215 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -550,14 +550,59 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
 
 static int idxd_enable_system_pasid(struct idxd_device *idxd)
 {
-	return -EOPNOTSUPP;
+	struct pci_dev *pdev = idxd->pdev;
+	struct device *dev = &pdev->dev;
+	struct iommu_domain *domain;
+	ioasid_t pasid;
+	int ret;
+
+	/*
+	 * Attach a global PASID to the DMA domain so that we can use ENQCMDS
+	 * to submit work on buffers mapped by DMA API.
+	 */
+	domain = iommu_get_domain_for_dev(dev);
+	if (!domain)
+		return -EPERM;
+
+	pasid = iommu_alloc_global_pasid(dev);
+	if (pasid == IOMMU_PASID_INVALID)
+		return -ENOSPC;
+
+	/*
+	 * DMA domain is owned by the driver, it should support all valid
+	 * types such as DMA-FQ, identity, etc.
+	 */
+	ret = iommu_attach_device_pasid(domain, dev, pasid);
+	if (ret) {
+		dev_err(dev, "failed to attach device pasid %d, domain type %d",
+			pasid, domain->type);
+		iommu_free_global_pasid(pasid);
+		return ret;
+	}
+
+	/* Since we set user privilege for kernel DMA, enable completion IRQ */
+	idxd_set_user_intr(idxd, 1);
+	idxd->pasid = pasid;
+
+	return ret;
 }
 
 static void idxd_disable_system_pasid(struct idxd_device *idxd)
 {
+	struct pci_dev *pdev = idxd->pdev;
+	struct device *dev = &pdev->dev;
+	struct iommu_domain *domain;
+
+	domain = iommu_get_domain_for_dev(dev);
+	if (!domain)
+		return;
+
+	iommu_detach_device_pasid(domain, dev, idxd->pasid);
+	iommu_free_global_pasid(idxd->pasid);
 
-	iommu_sva_unbind_device(idxd->sva);
+	idxd_set_user_intr(idxd, 0);
 	idxd->sva = NULL;
+	idxd->pasid = IOMMU_PASID_INVALID;
 }
 
 static int idxd_enable_sva(struct pci_dev *pdev)
@@ -600,8 +645,9 @@ static int idxd_probe(struct idxd_device *idxd)
 		} else {
 			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
 
-			if (idxd_enable_system_pasid(idxd))
-				dev_warn(dev, "No in-kernel DMA with PASID.\n");
+			rc = idxd_enable_system_pasid(idxd);
+			if (rc)
+				dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
 			else
 				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 		}