Merge git://git.infradead.org/intel-iommu

Pull IOMMU fixes from David Woodhouse:
 "Two minor fixes.

  The first fixes the assignment of SR-IOV virtual functions to the
  correct IOMMU unit, and the second fixes the excessively large (and
  physically contiguous) PASID tables used with SVM"

* git://git.infradead.org/intel-iommu:
  iommu/vt-d: Fix PASID table allocation
  iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions

Author: torvalds

drivers/iommu/dmar.c

@@ -338,7 +338,9 @@ static int dmar_pci_bus_notifier(struct notifier_block *nb,
 	struct pci_dev *pdev = to_pci_dev(data);
 	struct dmar_pci_notify_info *info;
 
-	/* Only care about add/remove events for physical functions */
+	/* Only care about add/remove events for physical functions.
+	 * For VFs we actually do the lookup based on the corresponding
+	 * PF in device_to_iommu() anyway. */
 	if (pdev->is_virtfn)
 		return NOTIFY_DONE;
 	if (action != BUS_NOTIFY_ADD_DEVICE &&

drivers/iommu/intel-iommu.c

@@ -892,7 +892,13 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf
 		return NULL;
 
 	if (dev_is_pci(dev)) {
+		struct pci_dev *pf_pdev;
+
 		pdev = to_pci_dev(dev);
+		/* VFs aren't listed in scope tables; we need to look up
+		 * the PF instead to find the IOMMU. */
+		pf_pdev = pci_physfn(pdev);
+		dev = &pf_pdev->dev;
 		segment = pci_domain_nr(pdev->bus);
 	} else if (has_acpi_companion(dev))
 		dev = &ACPI_COMPANION(dev)->dev;
@@ -905,6 +911,13 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf
 		for_each_active_dev_scope(drhd->devices,
 					  drhd->devices_cnt, i, tmp) {
 			if (tmp == dev) {
+				/* For a VF use its original BDF# not that of the PF
+				 * which we used for the IOMMU lookup. Strictly speaking
+				 * we could do this for all PCI devices; we only need to
+				 * get the BDF# from the scope table for ACPI matches. */
+				if (pdev->is_virtfn)
+					goto got_pdev;
+
 				*bus = drhd->devices[i].bus;
 				*devfn = drhd->devices[i].devfn;
 				goto out;

drivers/iommu/intel-svm.c

@@ -39,10 +39,18 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 	struct page *pages;
 	int order;
 
-	order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
-	if (order < 0)
-		order = 0;
-
+	/* Start at 2 because it's defined as 2^(1+PSS) */
+	iommu->pasid_max = 2 << ecap_pss(iommu->ecap);
+
+	/* Eventually I'm promised we will get a multi-level PASID table
+	 * and it won't have to be physically contiguous. Until then,
+	 * limit the size because 8MiB contiguous allocations can be hard
+	 * to come by. The limit of 0x20000, which is 1MiB for each of
+	 * the PASID and PASID-state tables, is somewhat arbitrary. */
+	if (iommu->pasid_max > 0x20000)
+		iommu->pasid_max = 0x20000;
+
+	order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max);
 	pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
 	if (!pages) {
 		pr_warn("IOMMU: %s: Failed to allocate PASID table\n",
@@ -53,6 +61,8 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 	pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order);
 
 	if (ecap_dis(iommu->ecap)) {
+		/* Just making it explicit... */
+		BUILD_BUG_ON(sizeof(struct pasid_entry) != sizeof(struct pasid_state_entry));
 		pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
 		if (pages)
 			iommu->pasid_state_table = page_address(pages);
@@ -68,11 +78,7 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 
 int intel_svm_free_pasid_tables(struct intel_iommu *iommu)
 {
-	int order;
-
-	order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
-	if (order < 0)
-		order = 0;
+	int order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max);
 
 	if (iommu->pasid_table) {
 		free_pages((unsigned long)iommu->pasid_table, order);
@@ -371,8 +377,8 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 		}
 		svm->iommu = iommu;
 
-		if (pasid_max > 2 << ecap_pss(iommu->ecap))
-			pasid_max = 2 << ecap_pss(iommu->ecap);
+		if (pasid_max > iommu->pasid_max)
+			pasid_max = iommu->pasid_max;
 
 		/* Do not use PASID 0 in caching mode (virtualised IOMMU) */
 		ret = idr_alloc(&iommu->pasid_idr, svm,

include/linux/intel-iommu.h

@@ -429,6 +429,7 @@ struct intel_iommu {
 	struct page_req_dsc *prq;
 	unsigned char prq_name[16];    /* Name for PRQ interrupt */
 	struct idr pasid_idr;
+	u32 pasid_max;
 #endif
 	struct q_inval  *qi;            /* Queued invalidation info */
 	u32 *iommu_state; /* Store iommu states between suspend and resume.*/