iommu/vt-d: Reduce duplicated code to handle virtual machine domains

Reduce duplicated code to handle virtual machine domains, there's no
functionality changes. It also improves code readability.

Signed-off-by: Jiang Liu <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

Author: Jiang Liu

drivers/iommu/intel-iommu.c

@@ -425,9 +425,12 @@ static LIST_HEAD(unmaps_to_do);
 static int timer_on;
 static long list_size;
 
+static void domain_exit(struct dmar_domain *domain);
 static void domain_remove_dev_info(struct dmar_domain *domain);
 static void domain_remove_one_dev_info(struct dmar_domain *domain,
 				       struct pci_dev *pdev);
+static void iommu_detach_dependent_devices(struct intel_iommu *iommu,
+					   struct pci_dev *pdev);
 
 #ifdef CONFIG_INTEL_IOMMU_DEFAULT_ON
 int dmar_disabled = 0;
@@ -1286,10 +1289,6 @@ static int iommu_init_domains(struct intel_iommu *iommu)
 	return 0;
 }
 
-
-static void domain_exit(struct dmar_domain *domain);
-static void vm_domain_exit(struct dmar_domain *domain);
-
 static void free_dmar_iommu(struct intel_iommu *iommu)
 {
 	struct dmar_domain *domain;
@@ -1304,12 +1303,8 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 			spin_lock_irqsave(&domain->iommu_lock, flags);
 			count = --domain->iommu_count;
 			spin_unlock_irqrestore(&domain->iommu_lock, flags);
-			if (count == 0) {
-				if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
-					vm_domain_exit(domain);
-				else
-					domain_exit(domain);
-			}
+			if (count == 0)
+				domain_exit(domain);
 		}
 	}
 
@@ -1327,17 +1322,26 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 	free_context_table(iommu);
 }
 
-static struct dmar_domain *alloc_domain(void)
+static struct dmar_domain *alloc_domain(bool vm)
 {
+	/* domain id for virtual machine, it won't be set in context */
+	static atomic_t vm_domid = ATOMIC_INIT(0);
 	struct dmar_domain *domain;
 
 	domain = alloc_domain_mem();
 	if (!domain)
 		return NULL;
 
 	domain->nid = -1;
+	domain->iommu_count = 0;
 	memset(domain->iommu_bmp, 0, sizeof(domain->iommu_bmp));
 	domain->flags = 0;
+	spin_lock_init(&domain->iommu_lock);
+	INIT_LIST_HEAD(&domain->devices);
+	if (vm) {
+		domain->id = atomic_inc_return(&vm_domid);
+		domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;
+	}
 
 	return domain;
 }
@@ -1374,22 +1378,16 @@ static void iommu_detach_domain(struct dmar_domain *domain,
 {
 	unsigned long flags;
 	int num, ndomains;
-	int found = 0;
 
 	spin_lock_irqsave(&iommu->lock, flags);
 	ndomains = cap_ndoms(iommu->cap);
 	for_each_set_bit(num, iommu->domain_ids, ndomains) {
 		if (iommu->domains[num] == domain) {
-			found = 1;
+			clear_bit(num, iommu->domain_ids);
+			iommu->domains[num] = NULL;
 			break;
 		}
 	}
-
-	if (found) {
-		clear_bit(num, iommu->domain_ids);
-		clear_bit(iommu->seq_id, domain->iommu_bmp);
-		iommu->domains[num] = NULL;
-	}
 	spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
@@ -1461,8 +1459,6 @@ static int domain_init(struct dmar_domain *domain, int guest_width)
 	unsigned long sagaw;
 
 	init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
-	spin_lock_init(&domain->iommu_lock);
-
 	domain_reserve_special_ranges(domain);
 
 	/* calculate AGAW */
@@ -1481,7 +1477,6 @@ static int domain_init(struct dmar_domain *domain, int guest_width)
 			return -ENODEV;
 	}
 	domain->agaw = agaw;
-	INIT_LIST_HEAD(&domain->devices);
 
 	if (ecap_coherent(iommu->ecap))
 		domain->iommu_coherency = 1;
@@ -1518,7 +1513,9 @@ static void domain_exit(struct dmar_domain *domain)
 	if (!intel_iommu_strict)
 		flush_unmaps_timeout(0);
 
+	/* remove associated devices */
 	domain_remove_dev_info(domain);
+
 	/* destroy iovas */
 	put_iova_domain(&domain->iovad);
 
@@ -1528,8 +1525,10 @@ static void domain_exit(struct dmar_domain *domain)
 	/* free page tables */
 	dma_pte_free_pagetable(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
 
+	/* clear attached or cached domains */
 	for_each_active_iommu(iommu, drhd)
-		if (test_bit(iommu->seq_id, domain->iommu_bmp))
+		if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
+		    test_bit(iommu->seq_id, domain->iommu_bmp))
 			iommu_detach_domain(domain, iommu);
 
 	free_domain_mem(domain);
@@ -1921,7 +1920,7 @@ static inline void unlink_domain_info(struct device_domain_info *info)
 static void domain_remove_dev_info(struct dmar_domain *domain)
 {
 	struct device_domain_info *info;
-	unsigned long flags;
+	unsigned long flags, flags2;
 	struct intel_iommu *iommu;
 
 	spin_lock_irqsave(&device_domain_lock, flags);
@@ -1934,8 +1933,22 @@ static void domain_remove_dev_info(struct dmar_domain *domain)
 		iommu_disable_dev_iotlb(info);
 		iommu = device_to_iommu(info->segment, info->bus, info->devfn);
 		iommu_detach_dev(iommu, info->bus, info->devfn);
-		free_devinfo_mem(info);
 
+		if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) {
+			iommu_detach_dependent_devices(iommu, info->dev);
+			/* clear this iommu in iommu_bmp, update iommu count
+			 * and capabilities
+			 */
+			spin_lock_irqsave(&domain->iommu_lock, flags2);
+			if (test_and_clear_bit(iommu->seq_id,
+					       domain->iommu_bmp)) {
+				domain->iommu_count--;
+				domain_update_iommu_cap(domain);
+			}
+			spin_unlock_irqrestore(&domain->iommu_lock, flags2);
+		}
+
+		free_devinfo_mem(info);
 		spin_lock_irqsave(&device_domain_lock, flags);
 	}
 	spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -2055,7 +2068,7 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
 	iommu = drhd->iommu;
 
 	/* Allocate and intialize new domain for the device */
-	domain = alloc_domain();
+	domain = alloc_domain(false);
 	if (!domain)
 		goto error;
 	if (iommu_attach_domain(domain, iommu)) {
@@ -2220,10 +2233,12 @@ static int __init si_domain_init(int hw)
 	struct intel_iommu *iommu;
 	int nid, ret = 0;
 
-	si_domain = alloc_domain();
+	si_domain = alloc_domain(false);
 	if (!si_domain)
 		return -EFAULT;
 
+	si_domain->flags = DOMAIN_FLAG_STATIC_IDENTITY;
+
 	for_each_active_iommu(iommu, drhd) {
 		ret = iommu_attach_domain(si_domain, iommu);
 		if (ret) {
@@ -2237,7 +2252,6 @@ static int __init si_domain_init(int hw)
 		return -EFAULT;
 	}
 
-	si_domain->flags = DOMAIN_FLAG_STATIC_IDENTITY;
 	pr_debug("IOMMU: identity mapping domain is domain %d\n",
 		 si_domain->id);
 
@@ -3810,77 +3824,18 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain,
 	}
 }
 
-static void vm_domain_remove_all_dev_info(struct dmar_domain *domain)
-{
-	struct device_domain_info *info;
-	struct intel_iommu *iommu;
-	unsigned long flags1, flags2;
-
-	spin_lock_irqsave(&device_domain_lock, flags1);
-	while (!list_empty(&domain->devices)) {
-		info = list_entry(domain->devices.next,
-			struct device_domain_info, link);
-		unlink_domain_info(info);
-		spin_unlock_irqrestore(&device_domain_lock, flags1);
-
-		iommu_disable_dev_iotlb(info);
-		iommu = device_to_iommu(info->segment, info->bus, info->devfn);
-		iommu_detach_dev(iommu, info->bus, info->devfn);
-		iommu_detach_dependent_devices(iommu, info->dev);
-
-		/* clear this iommu in iommu_bmp, update iommu count
-		 * and capabilities
-		 */
-		spin_lock_irqsave(&domain->iommu_lock, flags2);
-		if (test_and_clear_bit(iommu->seq_id,
-				       domain->iommu_bmp)) {
-			domain->iommu_count--;
-			domain_update_iommu_cap(domain);
-		}
-		spin_unlock_irqrestore(&domain->iommu_lock, flags2);
-
-		free_devinfo_mem(info);
-		spin_lock_irqsave(&device_domain_lock, flags1);
-	}
-	spin_unlock_irqrestore(&device_domain_lock, flags1);
-}
-
-/* domain id for virtual machine, it won't be set in context */
-static atomic_t vm_domid = ATOMIC_INIT(0);
-
-static struct dmar_domain *iommu_alloc_vm_domain(void)
-{
-	struct dmar_domain *domain;
-
-	domain = alloc_domain_mem();
-	if (!domain)
-		return NULL;
-
-	domain->id = atomic_inc_return(&vm_domid);
-	domain->nid = -1;
-	memset(domain->iommu_bmp, 0, sizeof(domain->iommu_bmp));
-	domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;
-
-	return domain;
-}
-
 static int md_domain_init(struct dmar_domain *domain, int guest_width)
 {
 	int adjust_width;
 
 	init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
-	spin_lock_init(&domain->iommu_lock);
-
 	domain_reserve_special_ranges(domain);
 
 	/* calculate AGAW */
 	domain->gaw = guest_width;
 	adjust_width = guestwidth_to_adjustwidth(guest_width);
 	domain->agaw = width_to_agaw(adjust_width);
 
-	INIT_LIST_HEAD(&domain->devices);
-
-	domain->iommu_count = 0;
 	domain->iommu_coherency = 0;
 	domain->iommu_snooping = 0;
 	domain->iommu_superpage = 0;
@@ -3895,53 +3850,11 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
 	return 0;
 }
 
-static void iommu_free_vm_domain(struct dmar_domain *domain)
-{
-	unsigned long flags;
-	struct dmar_drhd_unit *drhd;
-	struct intel_iommu *iommu;
-	unsigned long i;
-	unsigned long ndomains;
-
-	for_each_active_iommu(iommu, drhd) {
-		ndomains = cap_ndoms(iommu->cap);
-		for_each_set_bit(i, iommu->domain_ids, ndomains) {
-			if (iommu->domains[i] == domain) {
-				spin_lock_irqsave(&iommu->lock, flags);
-				clear_bit(i, iommu->domain_ids);
-				iommu->domains[i] = NULL;
-				spin_unlock_irqrestore(&iommu->lock, flags);
-				break;
-			}
-		}
-	}
-}
-
-static void vm_domain_exit(struct dmar_domain *domain)
-{
-	/* Domain 0 is reserved, so dont process it */
-	if (!domain)
-		return;
-
-	vm_domain_remove_all_dev_info(domain);
-	/* destroy iovas */
-	put_iova_domain(&domain->iovad);
-
-	/* clear ptes */
-	dma_pte_clear_range(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
-
-	/* free page tables */
-	dma_pte_free_pagetable(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
-
-	iommu_free_vm_domain(domain);
-	free_domain_mem(domain);
-}
-
 static int intel_iommu_domain_init(struct iommu_domain *domain)
 {
 	struct dmar_domain *dmar_domain;
 
-	dmar_domain = iommu_alloc_vm_domain();
+	dmar_domain = alloc_domain(true);
 	if (!dmar_domain) {
 		printk(KERN_ERR
 			"intel_iommu_domain_init: dmar_domain == NULL\n");
@@ -3950,7 +3863,7 @@ static int intel_iommu_domain_init(struct iommu_domain *domain)
 	if (md_domain_init(dmar_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
 		printk(KERN_ERR
 			"intel_iommu_domain_init() failed\n");
-		vm_domain_exit(dmar_domain);
+		domain_exit(dmar_domain);
 		return -ENOMEM;
 	}
 	domain_update_iommu_cap(dmar_domain);
@@ -3968,7 +3881,7 @@ static void intel_iommu_domain_destroy(struct iommu_domain *domain)
 	struct dmar_domain *dmar_domain = domain->priv;
 
 	domain->priv = NULL;
-	vm_domain_exit(dmar_domain);
+	domain_exit(dmar_domain);
 }
 
 static int intel_iommu_attach_device(struct iommu_domain *domain,