Linux-libre 4.6.2-gnu

1 files changed, 27 insertions, 23 deletions

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 20875341c..4ff73ff64 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -21,6 +21,7 @@
  */
 
 #include <linux/delay.h>
+#include <linux/dma-iommu.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/iommu.h>
@@ -1396,7 +1397,7 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 {
 	struct arm_smmu_domain *smmu_domain;
 
-	if (type != IOMMU_DOMAIN_UNMANAGED)
+	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
 		return NULL;
 
 	/*
@@ -1408,6 +1409,12 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 	if (!smmu_domain)
 		return NULL;
 
+	if (type == IOMMU_DOMAIN_DMA &&
+	    iommu_get_dma_cookie(&smmu_domain->domain)) {
+		kfree(smmu_domain);
+		return NULL;
+	}
+
 	mutex_init(&smmu_domain->init_mutex);
 	spin_lock_init(&smmu_domain->pgtbl_lock);
 	return &smmu_domain->domain;
@@ -1436,6 +1443,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 
+	iommu_put_dma_cookie(domain);
 	free_io_pgtable_ops(smmu_domain->pgtbl_ops);
 
 	/* Free the CD and ASID, if we allocated them */
@@ -1630,6 +1638,17 @@ static int arm_smmu_install_ste_for_group(struct arm_smmu_group *smmu_group)
 	return 0;
 }
 
+static void arm_smmu_detach_dev(struct device *dev)
+{
+	struct arm_smmu_group *smmu_group = arm_smmu_group_get(dev);
+
+	smmu_group->ste.bypass = true;
+	if (IS_ERR_VALUE(arm_smmu_install_ste_for_group(smmu_group)))
+		dev_warn(dev, "failed to install bypass STE\n");
+
+	smmu_group->domain = NULL;
+}
+
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
 	int ret = 0;
@@ -1642,7 +1661,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 
 	/* Already attached to a different domain? */
 	if (smmu_group->domain && smmu_group->domain != smmu_domain)
-		return -EEXIST;
+		arm_smmu_detach_dev(dev);
 
 	smmu = smmu_group->smmu;
 	mutex_lock(&smmu_domain->init_mutex);
@@ -1668,7 +1687,12 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		goto out_unlock;
 
 	smmu_group->domain	= smmu_domain;
-	smmu_group->ste.bypass	= false;
+
+	/*
+	 * FIXME: This should always be "false" once we have IOMMU-backed
+	 * DMA ops for all devices behind the SMMU.
+	 */
+	smmu_group->ste.bypass	= domain->type == IOMMU_DOMAIN_DMA;
 
 	ret = arm_smmu_install_ste_for_group(smmu_group);
 	if (IS_ERR_VALUE(ret))
@@ -1679,25 +1703,6 @@ out_unlock:
 	return ret;
 }
 
-static void arm_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
-{
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-	struct arm_smmu_group *smmu_group = arm_smmu_group_get(dev);
-
-	BUG_ON(!smmu_domain);
-	BUG_ON(!smmu_group);
-
-	mutex_lock(&smmu_domain->init_mutex);
-	BUG_ON(smmu_group->domain != smmu_domain);
-
-	smmu_group->ste.bypass = true;
-	if (IS_ERR_VALUE(arm_smmu_install_ste_for_group(smmu_group)))
-		dev_warn(dev, "failed to install bypass STE\n");
-
-	smmu_group->domain = NULL;
-	mutex_unlock(&smmu_domain->init_mutex);
-}
-
 static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 			phys_addr_t paddr, size_t size, int prot)
 {
@@ -1935,7 +1940,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.domain_alloc		= arm_smmu_domain_alloc,
 	.domain_free		= arm_smmu_domain_free,
 	.attach_dev		= arm_smmu_attach_dev,
-	.detach_dev		= arm_smmu_detach_dev,
 	.map			= arm_smmu_map,
 	.unmap			= arm_smmu_unmap,
 	.iova_to_phys		= arm_smmu_iova_to_phys,