Promote the difference between strict and non-strict DMA domains from an
internal detail to a distinct domain feature and type, to pave the road
for exposing it through the sysfs default domain interface.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
  drivers/iommu/dma-iommu.c |  2 +-
  drivers/iommu/iommu.c     |  8 ++++++--
  include/linux/iommu.h     | 11 +++++++++++
  3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index e28396cea6eb..8b3545c01077 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c

@@ -1311,7 +1311,7 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)
  	 * The IOMMU core code allocates the default DMA domain, which the
  	 * underlying IOMMU driver needs to support via the dma-iommu layer.
  	 */
-	if (domain->type == IOMMU_DOMAIN_DMA) {
+	if (iommu_is_dma_domain(domain)) {
  		if (iommu_dma_init_domain(domain, dma_base, dma_limit, dev))
  			goto out_err;
  		dev->dma_ops = &iommu_dma_ops;

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index fa8109369f74..982545234cf3 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c

@@ -115,6 +115,7 @@ static const char *iommu_domain_type_str(unsigned int t)
  	case IOMMU_DOMAIN_UNMANAGED:
  		return "Unmanaged";
  	case IOMMU_DOMAIN_DMA:
+	case IOMMU_DOMAIN_DMA_FQ:
  		return "Translated";
  	default:
  		return "Unknown";

@@ -552,6 +553,9 @@ static ssize_t iommu_group_show_type(struct iommu_group *group,
  		case IOMMU_DOMAIN_DMA:
  			type = "DMA\n";
  			break;
+		case IOMMU_DOMAIN_DMA_FQ:
+			type = "DMA-FQ\n";
+			break;
  		}
  	}
  	mutex_unlock(&group->mutex);

@@ -765,7 +769,7 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group,
  	unsigned long pg_size;
  	int ret = 0;
  
-	if (!domain || domain->type != IOMMU_DOMAIN_DMA)
+	if (!domain || !iommu_is_dma_domain(domain))
  		return 0;
  
  	BUG_ON(!domain->pgsize_bitmap);

@@ -1947,7 +1951,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
  	/* Assume all sizes by default; the driver may override this later */
  	domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;
  
-	if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(domain)) {
+	if (iommu_is_dma_domain(domain) && iommu_get_dma_cookie(domain)) {
  		iommu_domain_free(domain);
  		domain = NULL;
  	}

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 141779d76035..046ba4d54cd2 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h

@@ -61,6 +61,7 @@ struct iommu_domain_geometry {
  #define __IOMMU_DOMAIN_DMA_API	(1U << 1)  /* Domain for use in DMA-API
  					      implementation              */
  #define __IOMMU_DOMAIN_PT	(1U << 2)  /* Domain is identity mapped   */
+#define __IOMMU_DOMAIN_DMA_FQ	(1U << 3)  /* DMA-API uses flush queue    */
  
  /*
   * This are the possible domain-types

@@ -73,12 +74,17 @@ struct iommu_domain_geometry {
   *	IOMMU_DOMAIN_DMA	- Internally used for DMA-API implementations.
   *				  This flag allows IOMMU drivers to implement
   *				  certain optimizations for these domains
+ *	IOMMU_DOMAIN_DMA_FQ	- As above, but definitely using batched TLB
+ *				  invalidation.
   */
  #define IOMMU_DOMAIN_BLOCKED	(0U)
  #define IOMMU_DOMAIN_IDENTITY	(__IOMMU_DOMAIN_PT)
  #define IOMMU_DOMAIN_UNMANAGED	(__IOMMU_DOMAIN_PAGING)
  #define IOMMU_DOMAIN_DMA	(__IOMMU_DOMAIN_PAGING |	\
  				 __IOMMU_DOMAIN_DMA_API)
+#define IOMMU_DOMAIN_DMA_FQ	(__IOMMU_DOMAIN_PAGING |	\
+				 __IOMMU_DOMAIN_DMA_API |	\
+				 __IOMMU_DOMAIN_DMA_FQ)
  
  struct iommu_domain {
  	unsigned type;

@@ -90,6 +96,11 @@ struct iommu_domain {
  	struct iommu_dma_cookie *iova_cookie;
  };
  
+static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
+{
+	return domain->type & __IOMMU_DOMAIN_DMA_API;
+}
+
  enum iommu_cap {
  	IOMMU_CAP_CACHE_COHERENCY,	/* IOMMU can enforce cache coherent DMA
  					   transactions */