iommu/vt-d: Decouple PASID & PRI enabling from SVA

Previously the PCI PASID and PRI capabilities are enabled in the path of
iommu device probe only if INTEL_IOMMU_SVM is configured and the device
supports ATS. As we've already decoupled the I/O page fault handler from
SVA, we could also decouple PASID and PRI enabling from it to make room
for growth of new features like kernel DMA with PASID, SIOV and nested
translation.

At the same time, the iommu_enable_dev_iotlb() helper is also called in
iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) path. It's unnecessary
and duplicate. This cleanups this helper to make the code neat.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20220915085814.2261409-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 16 insertions, 62 deletions

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 31bc50e538a3..af17177b6d76 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -199,6 +199,11 @@ static inline void context_set_domain_id(struct context_entry *context,
 	context->hi |= (value & ((1 << 16) - 1)) << 8;
 }
 
+static inline void context_set_pasid(struct context_entry *context)
+{
+	context->lo |= CONTEXT_PASIDE;
+}
+
 static inline int context_domain_id(struct context_entry *c)
 {
 	return((c->hi >> 8) & 0xffff);
@@ -1350,21 +1355,18 @@ static void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did,
 }
 
 static struct device_domain_info *
-iommu_support_dev_iotlb(struct dmar_domain *domain, struct intel_iommu *iommu,
-			u8 bus, u8 devfn)
+domain_lookup_dev_info(struct dmar_domain *domain,
+		       struct intel_iommu *iommu, u8 bus, u8 devfn)
 {
 	struct device_domain_info *info;
 	unsigned long flags;
 
-	if (!iommu->qi)
-		return NULL;
-
 	spin_lock_irqsave(&domain->lock, flags);
 	list_for_each_entry(info, &domain->devices, link) {
 		if (info->iommu == iommu && info->bus == bus &&
 		    info->devfn == devfn) {
 			spin_unlock_irqrestore(&domain->lock, flags);
-			return info->ats_supported ? info : NULL;
+			return info;
 		}
 	}
 	spin_unlock_irqrestore(&domain->lock, flags);
@@ -1389,7 +1391,7 @@ static void domain_update_iotlb(struct dmar_domain *domain)
 	spin_unlock_irqrestore(&domain->lock, flags);
 }
 
-static void iommu_enable_dev_iotlb(struct device_domain_info *info)
+static void iommu_enable_pci_caps(struct device_domain_info *info)
 {
 	struct pci_dev *pdev;
 
@@ -1412,7 +1414,6 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
 		info->pfsid = pci_dev_id(pf_pdev);
 	}
 
-#ifdef CONFIG_INTEL_IOMMU_SVM
 	/* The PCIe spec, in its wisdom, declares that the behaviour of
 	   the device if you enable PASID support after ATS support is
 	   undefined. So always enable PASID support on devices which
@@ -1425,7 +1426,7 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
 	    (info->pasid_enabled ? pci_prg_resp_pasid_required(pdev) : 1)  &&
 	    !pci_reset_pri(pdev) && !pci_enable_pri(pdev, PRQ_DEPTH))
 		info->pri_enabled = 1;
-#endif
+
 	if (info->ats_supported && pci_ats_page_aligned(pdev) &&
 	    !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
 		info->ats_enabled = 1;
@@ -1448,16 +1449,16 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
 		info->ats_enabled = 0;
 		domain_update_iotlb(info->domain);
 	}
-#ifdef CONFIG_INTEL_IOMMU_SVM
+
 	if (info->pri_enabled) {
 		pci_disable_pri(pdev);
 		info->pri_enabled = 0;
 	}
+
 	if (info->pasid_enabled) {
 		pci_disable_pasid(pdev);
 		info->pasid_enabled = 0;
 	}
-#endif
 }
 
 static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
@@ -1907,7 +1908,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 				      u8 bus, u8 devfn)
 {
 	struct device_domain_info *info =
-			iommu_support_dev_iotlb(domain, iommu, bus, devfn);
+			domain_lookup_dev_info(domain, iommu, bus, devfn);
 	u16 did = domain_id_iommu(domain, iommu);
 	int translation = CONTEXT_TT_MULTI_LEVEL;
 	struct context_entry *context;
@@ -1980,6 +1981,8 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 			context_set_sm_dte(context);
 		if (info && info->pri_supported)
 			context_set_sm_pre(context);
+		if (info && info->pasid_supported)
+			context_set_pasid(context);
 	} else {
 		struct dma_pte *pgd = domain->pgd;
 		int agaw;
@@ -2037,7 +2040,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 	} else {
 		iommu_flush_write_buffer(iommu);
 	}
-	iommu_enable_dev_iotlb(info);
+	iommu_enable_pci_caps(info);
 
 	ret = 0;
 
@@ -4574,52 +4577,6 @@ static void intel_iommu_get_resv_regions(struct device *device,
 	list_add_tail(&reg->list, head);
 }
 
-int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev)
-{
-	struct device_domain_info *info = dev_iommu_priv_get(dev);
-	struct context_entry *context;
-	struct dmar_domain *domain;
-	u64 ctx_lo;
-	int ret;
-
-	domain = info->domain;
-	if (!domain)
-		return -EINVAL;
-
-	spin_lock(&iommu->lock);
-	ret = -EINVAL;
-	if (!info->pasid_supported)
-		goto out;
-
-	context = iommu_context_addr(iommu, info->bus, info->devfn, 0);
-	if (WARN_ON(!context))
-		goto out;
-
-	ctx_lo = context[0].lo;
-
-	if (!(ctx_lo & CONTEXT_PASIDE)) {
-		ctx_lo |= CONTEXT_PASIDE;
-		context[0].lo = ctx_lo;
-		wmb();
-		iommu->flush.flush_context(iommu,
-					   domain_id_iommu(domain, iommu),
-					   PCI_DEVID(info->bus, info->devfn),
-					   DMA_CCMD_MASK_NOBIT,
-					   DMA_CCMD_DEVICE_INVL);
-	}
-
-	/* Enable PASID support in the device, if it wasn't already */
-	if (!info->pasid_enabled)
-		iommu_enable_dev_iotlb(info);
-
-	ret = 0;
-
- out:
-	spin_unlock(&iommu->lock);
-
-	return ret;
-}
-
 static struct iommu_group *intel_iommu_device_group(struct device *dev)
 {
 	if (dev_is_pci(dev))
@@ -4643,9 +4600,6 @@ static int intel_iommu_enable_sva(struct device *dev)
 	if (!(iommu->flags & VTD_FLAG_SVM_CAPABLE))
 		return -ENODEV;
 
-	if (intel_iommu_enable_pasid(iommu, dev))
-		return -ENODEV;
-
 	if (!info->pasid_enabled || !info->pri_enabled || !info->ats_enabled)
 		return -EINVAL;