Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

10 files changed, 240 insertions, 55 deletions

diff --git a/kernel/drivers/iommu/amd_iommu.c b/kernel/drivers/iommu/amd_iommu.c
index f417aafea..b08732bae 100644
--- a/kernel/drivers/iommu/amd_iommu.c
+++ b/kernel/drivers/iommu/amd_iommu.c
@@ -91,6 +91,7 @@ struct iommu_dev_data {
 	struct list_head dev_data_list;	  /* For global dev_data_list */
 	struct protection_domain *domain; /* Domain the device is bound to */
 	u16 devid;			  /* PCI Device ID */
+	u16 alias;			  /* Alias Device ID */
 	bool iommu_v2;			  /* Device can make use of IOMMUv2 */
 	bool passthrough;		  /* Device is identity mapped */
 	struct {
@@ -125,6 +126,13 @@ static struct protection_domain *to_pdomain(struct iommu_domain *dom)
 	return container_of(dom, struct protection_domain, domain);
 }
 
+static inline u16 get_device_id(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return PCI_DEVID(pdev->bus->number, pdev->devfn);
+}
+
 static struct iommu_dev_data *alloc_dev_data(u16 devid)
 {
 	struct iommu_dev_data *dev_data;
@@ -162,6 +170,68 @@ out_unlock:
 	return dev_data;
 }
 
+static int __last_alias(struct pci_dev *pdev, u16 alias, void *data)
+{
+	*(u16 *)data = alias;
+	return 0;
+}
+
+static u16 get_alias(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	u16 devid, ivrs_alias, pci_alias;
+
+	devid = get_device_id(dev);
+	ivrs_alias = amd_iommu_alias_table[devid];
+	pci_for_each_dma_alias(pdev, __last_alias, &pci_alias);
+
+	if (ivrs_alias == pci_alias)
+		return ivrs_alias;
+
+	/*
+	 * DMA alias showdown
+	 *
+	 * The IVRS is fairly reliable in telling us about aliases, but it
+	 * can't know about every screwy device.  If we don't have an IVRS
+	 * reported alias, use the PCI reported alias.  In that case we may
+	 * still need to initialize the rlookup and dev_table entries if the
+	 * alias is to a non-existent device.
+	 */
+	if (ivrs_alias == devid) {
+		if (!amd_iommu_rlookup_table[pci_alias]) {
+			amd_iommu_rlookup_table[pci_alias] =
+				amd_iommu_rlookup_table[devid];
+			memcpy(amd_iommu_dev_table[pci_alias].data,
+			       amd_iommu_dev_table[devid].data,
+			       sizeof(amd_iommu_dev_table[pci_alias].data));
+		}
+
+		return pci_alias;
+	}
+
+	pr_info("AMD-Vi: Using IVRS reported alias %02x:%02x.%d "
+		"for device %s[%04x:%04x], kernel reported alias "
+		"%02x:%02x.%d\n", PCI_BUS_NUM(ivrs_alias), PCI_SLOT(ivrs_alias),
+		PCI_FUNC(ivrs_alias), dev_name(dev), pdev->vendor, pdev->device,
+		PCI_BUS_NUM(pci_alias), PCI_SLOT(pci_alias),
+		PCI_FUNC(pci_alias));
+
+	/*
+	 * If we don't have a PCI DMA alias and the IVRS alias is on the same
+	 * bus, then the IVRS table may know about a quirk that we don't.
+	 */
+	if (pci_alias == devid &&
+	    PCI_BUS_NUM(ivrs_alias) == pdev->bus->number) {
+		pdev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN;
+		pdev->dma_alias_devfn = ivrs_alias & 0xff;
+		pr_info("AMD-Vi: Added PCI DMA alias %02x.%d for %s\n",
+			PCI_SLOT(ivrs_alias), PCI_FUNC(ivrs_alias),
+			dev_name(dev));
+	}
+
+	return ivrs_alias;
+}
+
 static struct iommu_dev_data *find_dev_data(u16 devid)
 {
 	struct iommu_dev_data *dev_data;
@@ -174,13 +244,6 @@ static struct iommu_dev_data *find_dev_data(u16 devid)
 	return dev_data;
 }
 
-static inline u16 get_device_id(struct device *dev)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-
-	return PCI_DEVID(pdev->bus->number, pdev->devfn);
-}
-
 static struct iommu_dev_data *get_dev_data(struct device *dev)
 {
 	return dev->archdata.iommu;
@@ -289,9 +352,11 @@ static void init_iommu_group(struct device *dev)
 	if (!domain)
 		goto out;
 
-	dma_domain = to_pdomain(domain)->priv;
+	if (to_pdomain(domain)->flags == PD_DMA_OPS_MASK) {
+		dma_domain = to_pdomain(domain)->priv;
+		init_unity_mappings_for_device(dev, dma_domain);
+	}
 
-	init_unity_mappings_for_device(dev, dma_domain);
 out:
 	iommu_group_put(group);
 }
@@ -308,6 +373,8 @@ static int iommu_init_device(struct device *dev)
 	if (!dev_data)
 		return -ENOMEM;
 
+	dev_data->alias = get_alias(dev);
+
 	if (pci_iommuv2_capable(pdev)) {
 		struct amd_iommu *iommu;
 
@@ -328,7 +395,7 @@ static void iommu_ignore_device(struct device *dev)
 	u16 devid, alias;
 
 	devid = get_device_id(dev);
-	alias = amd_iommu_alias_table[devid];
+	alias = get_alias(dev);
 
 	memset(&amd_iommu_dev_table[devid], 0, sizeof(struct dev_table_entry));
 	memset(&amd_iommu_dev_table[alias], 0, sizeof(struct dev_table_entry));
@@ -859,7 +926,7 @@ again:
 	next_tail = (tail + sizeof(*cmd)) % CMD_BUFFER_SIZE;
 	left      = (head - next_tail) % CMD_BUFFER_SIZE;
 
-	if (left <= 2) {
+	if (left <= 0x20) {
 		struct iommu_cmd sync_cmd;
 		volatile u64 sem = 0;
 		int ret;
@@ -1017,7 +1084,7 @@ static int device_flush_dte(struct iommu_dev_data *dev_data)
 	int ret;
 
 	iommu = amd_iommu_rlookup_table[dev_data->devid];
-	alias = amd_iommu_alias_table[dev_data->devid];
+	alias = dev_data->alias;
 
 	ret = iommu_flush_dte(iommu, dev_data->devid);
 	if (!ret && alias != dev_data->devid)
@@ -1766,6 +1833,9 @@ static void dma_ops_domain_free(struct dma_ops_domain *dom)
 		kfree(dom->aperture[i]);
 	}
 
+	if (dom->domain.id)
+		domain_id_free(dom->domain.id);
+
 	kfree(dom);
 }
 
@@ -1891,7 +1961,7 @@ static void do_attach(struct iommu_dev_data *dev_data,
 	bool ats;
 
 	iommu = amd_iommu_rlookup_table[dev_data->devid];
-	alias = amd_iommu_alias_table[dev_data->devid];
+	alias = dev_data->alias;
 	ats   = dev_data->ats.enabled;
 
 	/* Update data structures */
@@ -1925,7 +1995,7 @@ static void do_detach(struct iommu_dev_data *dev_data)
 		return;
 
 	iommu = amd_iommu_rlookup_table[dev_data->devid];
-	alias = amd_iommu_alias_table[dev_data->devid];
+	alias = dev_data->alias;
 
 	/* decrease reference counters */
 	dev_data->domain->dev_iommu[iommu->index] -= 1;
@@ -2257,8 +2327,15 @@ static void update_device_table(struct protection_domain *domain)
 {
 	struct iommu_dev_data *dev_data;
 
-	list_for_each_entry(dev_data, &domain->dev_list, list)
+	list_for_each_entry(dev_data, &domain->dev_list, list) {
 		set_dte_entry(dev_data->devid, domain, dev_data->ats.enabled);
+
+		if (dev_data->devid == dev_data->alias)
+			continue;
+
+		/* There is an alias, update device table entry for it */
+		set_dte_entry(dev_data->alias, domain, dev_data->ats.enabled);
+	}
 }
 
 static void update_domain(struct protection_domain *domain)
@@ -2905,9 +2982,7 @@ static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
 static void amd_iommu_domain_free(struct iommu_domain *dom)
 {
 	struct protection_domain *domain;
-
-	if (!dom)
-		return;
+	struct dma_ops_domain *dma_dom;
 
 	domain = to_pdomain(dom);
 
@@ -2916,13 +2991,24 @@ static void amd_iommu_domain_free(struct iommu_domain *dom)
 
 	BUG_ON(domain->dev_cnt != 0);
 
-	if (domain->mode != PAGE_MODE_NONE)
-		free_pagetable(domain);
+	if (!dom)
+		return;
 
-	if (domain->flags & PD_IOMMUV2_MASK)
-		free_gcr3_table(domain);
+	switch (dom->type) {
+	case IOMMU_DOMAIN_DMA:
+		dma_dom = domain->priv;
+		dma_ops_domain_free(dma_dom);
+		break;
+	default:
+		if (domain->mode != PAGE_MODE_NONE)
+			free_pagetable(domain);
 
-	protection_domain_free(domain);
+		if (domain->flags & PD_IOMMUV2_MASK)
+			free_gcr3_table(domain);
+
+		protection_domain_free(domain);
+		break;
+	}
 }
 
 static void amd_iommu_detach_device(struct iommu_domain *dom,
diff --git a/kernel/drivers/iommu/amd_iommu_init.c b/kernel/drivers/iommu/amd_iommu_init.c
index bf4959f42..94f1bf772 100644
--- a/kernel/drivers/iommu/amd_iommu_init.c
+++ b/kernel/drivers/iommu/amd_iommu_init.c
@@ -1363,13 +1363,23 @@ static int __init amd_iommu_init_pci(void)
 			break;
 	}
 
+	/*
+	 * Order is important here to make sure any unity map requirements are
+	 * fulfilled. The unity mappings are created and written to the device
+	 * table during the amd_iommu_init_api() call.
+	 *
+	 * After that we call init_device_table_dma() to make sure any
+	 * uninitialized DTE will block DMA, and in the end we flush the caches
+	 * of all IOMMUs to make sure the changes to the device table are
+	 * active.
+	 */
+	ret = amd_iommu_init_api();
+
 	init_device_table_dma();
 
 	for_each_iommu(iommu)
 		iommu_flush_all_caches(iommu);
 
-	ret = amd_iommu_init_api();
-
 	if (!ret)
 		print_iommu_info();
 
diff --git a/kernel/drivers/iommu/amd_iommu_v2.c b/kernel/drivers/iommu/amd_iommu_v2.c
index 7caf2fa23..4831eb910 100644
--- a/kernel/drivers/iommu/amd_iommu_v2.c
+++ b/kernel/drivers/iommu/amd_iommu_v2.c
@@ -809,8 +809,10 @@ int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
 		goto out_free_domain;
 
 	group = iommu_group_get(&pdev->dev);
-	if (!group)
+	if (!group) {
+		ret = -EINVAL;
 		goto out_free_domain;
+	}
 
 	ret = iommu_attach_group(dev_state->domain, group);
 	if (ret != 0)
diff --git a/kernel/drivers/iommu/arm-smmu-v3.c b/kernel/drivers/iommu/arm-smmu-v3.c
index 4e5118a4c..00df3832f 100644
--- a/kernel/drivers/iommu/arm-smmu-v3.c
+++ b/kernel/drivers/iommu/arm-smmu-v3.c
@@ -870,7 +870,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu)
 	 * We may have concurrent producers, so we need to be careful
 	 * not to touch any of the shadow cmdq state.
 	 */
-	queue_read(cmd, Q_ENT(q, idx), q->ent_dwords);
+	queue_read(cmd, Q_ENT(q, cons), q->ent_dwords);
 	dev_err(smmu->dev, "skipping command in error state:\n");
 	for (i = 0; i < ARRAY_SIZE(cmd); ++i)
 		dev_err(smmu->dev, "\t0x%016llx\n", (unsigned long long)cmd[i]);
@@ -881,7 +881,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu)
 		return;
 	}
 
-	queue_write(cmd, Q_ENT(q, idx), q->ent_dwords);
+	queue_write(Q_ENT(q, cons), cmd, q->ent_dwords);
 }
 
 static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
@@ -1025,6 +1025,9 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 		case STRTAB_STE_0_CFG_S2_TRANS:
 			ste_live = true;
 			break;
+		case STRTAB_STE_0_CFG_ABORT:
+			if (disable_bypass)
+				break;
 		default:
 			BUG(); /* STE corruption */
 		}
@@ -1919,6 +1922,7 @@ static struct iommu_ops arm_smmu_ops = {
 	.detach_dev		= arm_smmu_detach_dev,
 	.map			= arm_smmu_map,
 	.unmap			= arm_smmu_unmap,
+	.map_sg			= default_iommu_map_sg,
 	.iova_to_phys		= arm_smmu_iova_to_phys,
 	.add_device		= arm_smmu_add_device,
 	.remove_device		= arm_smmu_remove_device,
diff --git a/kernel/drivers/iommu/dma-iommu.c b/kernel/drivers/iommu/dma-iommu.c
index 72d618266..347a3c17f 100644
--- a/kernel/drivers/iommu/dma-iommu.c
+++ b/kernel/drivers/iommu/dma-iommu.c
@@ -68,7 +68,8 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 	if (!iovad)
 		return;
 
-	put_iova_domain(iovad);
+	if (iovad->granule)
+		put_iova_domain(iovad);
 	kfree(iovad);
 	domain->iova_cookie = NULL;
 }
@@ -403,7 +404,7 @@ static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents,
 		unsigned int s_length = sg_dma_len(s);
 		unsigned int s_dma_len = s->length;
 
-		s->offset = s_offset;
+		s->offset += s_offset;
 		s->length = s_length;
 		sg_dma_address(s) = dma_addr + s_offset;
 		dma_addr += s_dma_len;
@@ -422,7 +423,7 @@ static void __invalidate_sg(struct scatterlist *sg, int nents)
 
 	for_each_sg(sg, s, nents, i) {
 		if (sg_dma_address(s) != DMA_ERROR_CODE)
-			s->offset = sg_dma_address(s);
+			s->offset += sg_dma_address(s);
 		if (sg_dma_len(s))
 			s->length = sg_dma_len(s);
 		sg_dma_address(s) = DMA_ERROR_CODE;
diff --git a/kernel/drivers/iommu/dmar.c b/kernel/drivers/iommu/dmar.c
index 3821c4786..e913a930a 100644
--- a/kernel/drivers/iommu/dmar.c
+++ b/kernel/drivers/iommu/dmar.c
@@ -326,7 +326,9 @@ 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 &&
@@ -1858,10 +1860,11 @@ static int dmar_hp_remove_drhd(struct acpi_dmar_header *header, void *arg)
 	/*
 	 * All PCI devices managed by this unit should have been destroyed.
 	 */
-	if (!dmaru->include_all && dmaru->devices && dmaru->devices_cnt)
+	if (!dmaru->include_all && dmaru->devices && dmaru->devices_cnt) {
 		for_each_active_dev_scope(dmaru->devices,
 					  dmaru->devices_cnt, i, dev)
 			return -EBUSY;
+	}
 
 	ret = dmar_ir_hotplug(dmaru, false);
 	if (ret == 0)
diff --git a/kernel/drivers/iommu/exynos-iommu.c b/kernel/drivers/iommu/exynos-iommu.c
index 97c41b8ab..29a31eb9a 100644
--- a/kernel/drivers/iommu/exynos-iommu.c
+++ b/kernel/drivers/iommu/exynos-iommu.c
@@ -647,6 +647,7 @@ static struct platform_driver exynos_sysmmu_driver __refdata = {
 		.name		= "exynos-sysmmu",
 		.of_match_table	= sysmmu_of_match,
 		.pm		= &sysmmu_pm_ops,
+		.suppress_bind_attrs = true,
 	}
 };
 
diff --git a/kernel/drivers/iommu/intel-iommu.c b/kernel/drivers/iommu/intel-iommu.c
index a2e1b7f14..9413b0726 100644
--- a/kernel/drivers/iommu/intel-iommu.c
+++ b/kernel/drivers/iommu/intel-iommu.c
@@ -885,7 +885,13 @@ 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;
@@ -898,6 +904,13 @@ 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;
@@ -1672,6 +1685,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
 	if (!iommu->domains || !iommu->domain_ids)
 		return;
 
+again:
 	spin_lock_irqsave(&device_domain_lock, flags);
 	list_for_each_entry_safe(info, tmp, &device_domain_list, global) {
 		struct dmar_domain *domain;
@@ -1684,10 +1698,19 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
 
 		domain = info->domain;
 
-		dmar_remove_one_dev_info(domain, info->dev);
+		__dmar_remove_one_dev_info(info);
 
-		if (!domain_type_is_vm_or_si(domain))
+		if (!domain_type_is_vm_or_si(domain)) {
+			/*
+			 * The domain_exit() function  can't be called under
+			 * device_domain_lock, as it takes this lock itself.
+			 * So release the lock here and re-run the loop
+			 * afterwards.
+			 */
+			spin_unlock_irqrestore(&device_domain_lock, flags);
 			domain_exit(domain);
+			goto again;
+		}
 	}
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 
@@ -1970,6 +1993,25 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 	if (context_present(context))
 		goto out_unlock;
 
+	/*
+	 * For kdump cases, old valid entries may be cached due to the
+	 * in-flight DMA and copied pgtable, but there is no unmapping
+	 * behaviour for them, thus we need an explicit cache flush for
+	 * the newly-mapped device. For kdump, at this point, the device
+	 * is supposed to finish reset at its driver probe stage, so no
+	 * in-flight DMA will exist, and we don't need to worry anymore
+	 * hereafter.
+	 */
+	if (context_copied(context)) {
+		u16 did_old = context_domain_id(context);
+
+		if (did_old >= 0 && did_old < cap_ndoms(iommu->cap))
+			iommu->flush.flush_context(iommu, did_old,
+						   (((u16)bus) << 8) | devfn,
+						   DMA_CCMD_MASK_NOBIT,
+						   DMA_CCMD_DEVICE_INVL);
+	}
+
 	pgd = domain->pgd;
 
 	context_clear_entry(context);
@@ -2032,7 +2074,7 @@ out_unlock:
 	spin_unlock(&iommu->lock);
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 
-	return 0;
+	return ret;
 }
 
 struct domain_context_mapping_data {
@@ -3169,11 +3211,6 @@ static int __init init_dmars(void)
 			}
 		}
 
-		iommu_flush_write_buffer(iommu);
-		iommu_set_root_entry(iommu);
-		iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
-		iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
-
 		if (!ecap_pass_through(iommu->ecap))
 			hw_pass_through = 0;
 #ifdef CONFIG_INTEL_IOMMU_SVM
@@ -3182,6 +3219,18 @@ static int __init init_dmars(void)
 #endif
 	}
 
+	/*
+	 * Now that qi is enabled on all iommus, set the root entry and flush
+	 * caches. This is required on some Intel X58 chipsets, otherwise the
+	 * flush_context function will loop forever and the boot hangs.
+	 */
+	for_each_active_iommu(iommu, drhd) {
+		iommu_flush_write_buffer(iommu);
+		iommu_set_root_entry(iommu);
+		iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
+		iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+	}
+
 	if (iommu_pass_through)
 		iommu_identity_mapping |= IDENTMAP_ALL;
 
@@ -4175,10 +4224,11 @@ int dmar_check_one_atsr(struct acpi_dmar_header *hdr, void *arg)
 	if (!atsru)
 		return 0;
 
-	if (!atsru->include_all && atsru->devices && atsru->devices_cnt)
+	if (!atsru->include_all && atsru->devices && atsru->devices_cnt) {
 		for_each_active_dev_scope(atsru->devices, atsru->devices_cnt,
 					  i, dev)
 			return -EBUSY;
+	}
 
 	return 0;
 }
@@ -4989,6 +5039,25 @@ static void intel_iommu_remove_device(struct device *dev)
 }
 
 #ifdef CONFIG_INTEL_IOMMU_SVM
+#define MAX_NR_PASID_BITS (20)
+static inline unsigned long intel_iommu_get_pts(struct intel_iommu *iommu)
+{
+	/*
+	 * Convert ecap_pss to extend context entry pts encoding, also
+	 * respect the soft pasid_max value set by the iommu.
+	 * - number of PASID bits = ecap_pss + 1
+	 * - number of PASID table entries = 2^(pts + 5)
+	 * Therefore, pts = ecap_pss - 4
+	 * e.g. KBL ecap_pss = 0x13, PASID has 20 bits, pts = 15
+	 */
+	if (ecap_pss(iommu->ecap) < 5)
+		return 0;
+
+	/* pasid_max is encoded as actual number of entries not the bits */
+	return find_first_bit((unsigned long *)&iommu->pasid_max,
+			MAX_NR_PASID_BITS) - 5;
+}
+
 int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sdev)
 {
 	struct device_domain_info *info;
@@ -5021,7 +5090,9 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
 
 	if (!(ctx_lo & CONTEXT_PASIDE)) {
 		context[1].hi = (u64)virt_to_phys(iommu->pasid_state_table);
-		context[1].lo = (u64)virt_to_phys(iommu->pasid_table) | ecap_pss(iommu->ecap);
+		context[1].lo = (u64)virt_to_phys(iommu->pasid_table) |
+			intel_iommu_get_pts(iommu);
+
 		wmb();
 		/* CONTEXT_TT_MULTI_LEVEL and CONTEXT_TT_DEV_IOTLB are both
 		 * extended to permit requests-with-PASID if the PASIDE bit
diff --git a/kernel/drivers/iommu/intel-svm.c b/kernel/drivers/iommu/intel-svm.c
index d9939fa9b..f929879ec 100644
--- a/kernel/drivers/iommu/intel-svm.c
+++ b/kernel/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,
diff --git a/kernel/drivers/iommu/iommu.c b/kernel/drivers/iommu/iommu.c
index 0e3b0092e..515bb8b80 100644
--- a/kernel/drivers/iommu/iommu.c
+++ b/kernel/drivers/iommu/iommu.c
@@ -848,7 +848,8 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 	if (!group->default_domain) {
 		group->default_domain = __iommu_domain_alloc(dev->bus,
 							     IOMMU_DOMAIN_DMA);
-		group->domain = group->default_domain;
+		if (!group->domain)
+			group->domain = group->default_domain;
 	}
 
 	ret = iommu_group_add_device(group, dev);