x86/amd-iommu: Keep devices per domain in a list

This patch introduces a list to each protection domain which
keeps all devices associated with the domain. This can be
used later to optimize certain functions and to completly
remove the amd_iommu_pd_table.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/include/asm/amd_iommu_types.h

@@ -235,6 +235,7 @@ extern bool amd_iommu_np_cache;
  */
 struct protection_domain {
 	struct list_head list;  /* for list of all protection domains */
+	struct list_head dev_list; /* List of all devices in this domain */
 	spinlock_t lock;	/* mostly used to lock the page table*/
 	u16 id;			/* the domain id written to the device table */
 	int mode;		/* paging mode (0-6 levels) */
@@ -251,6 +252,7 @@ struct protection_domain {
  * This struct contains device specific data for the IOMMU
  */
 struct iommu_dev_data {
+	struct list_head list;		  /* For domain->dev_list */
 	struct device *alias;		  /* The Alias Device */
 	struct protection_domain *domain; /* Domain the device is bound to */
 	atomic_t bind;			  /* Domain attach reverent count */

arch/x86/kernel/amd_iommu.c

@@ -1286,6 +1286,7 @@ static struct dma_ops_domain *dma_ops_domain_alloc(void)
 	dma_dom->domain.id = domain_id_alloc();
 	if (dma_dom->domain.id == 0)
 		goto free_dma_dom;
+	INIT_LIST_HEAD(&dma_dom->domain.dev_list);
 	dma_dom->domain.mode = PAGE_MODE_2_LEVEL;
 	dma_dom->domain.pt_root = (void *)get_zeroed_page(GFP_KERNEL);
 	dma_dom->domain.flags = PD_DMA_OPS_MASK;
@@ -1408,6 +1409,7 @@ static int __attach_device(struct device *dev,
 	if (alias != devid) {
 		if (alias_data->domain == NULL) {
 			alias_data->domain = domain;
+			list_add(&alias_data->list, &domain->dev_list);
 			set_dte_entry(alias, domain);
 		}
 
@@ -1416,6 +1418,7 @@ static int __attach_device(struct device *dev,
 
 	if (dev_data->domain == NULL) {
 		dev_data->domain = domain;
+		list_add(&dev_data->list, &domain->dev_list);
 		set_dte_entry(devid, domain);
 	}
 
@@ -1460,6 +1463,7 @@ static void __detach_device(struct device *dev)
 	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
 	struct iommu_dev_data *dev_data = get_dev_data(dev);
 	struct iommu_dev_data *alias_data;
+	unsigned long flags;
 
 	BUG_ON(!iommu);
 
@@ -1469,13 +1473,19 @@ static void __detach_device(struct device *dev)
 	if (devid != alias) {
 		alias_data = get_dev_data(dev_data->alias);
 		if (atomic_dec_and_test(&alias_data->bind)) {
+			spin_lock_irqsave(&alias_data->domain->lock, flags);
 			clear_dte_entry(alias);
+			list_del(&alias_data->list);
+			spin_unlock_irqrestore(&alias_data->domain->lock, flags);
 			alias_data->domain = NULL;
 		}
 	}
 
 	if (atomic_dec_and_test(&dev_data->bind)) {
+		spin_lock_irqsave(&dev_data->domain->lock, flags);
 		clear_dte_entry(devid);
+		list_del(&dev_data->list);
+		spin_unlock_irqrestore(&dev_data->domain->lock, flags);
 		dev_data->domain = NULL;
 	}
 
@@ -2294,6 +2304,7 @@ static struct protection_domain *protection_domain_alloc(void)
 	domain->id = domain_id_alloc();
 	if (!domain->id)
 		goto out_err;
+	INIT_LIST_HEAD(&domain->dev_list);
 
 	add_domain_to_list(domain);