1. Save the related domain pointer in struct iommu_dma_cookie, make iovad
    capable call domain->ops->flush_iotlb_all to flush TLB.
2. During the iommu domain initialization phase, base on domain->non_strict
    field to check whether non-strict mode is supported or not. If so, call
    init_iova_flush_queue to register iovad->flush_cb callback.
3. All unmap(contains iova-free) APIs will finally invoke __iommu_dma_unmap
    -->iommu_dma_free_iova. If the domain is non-strict, call queue_iova to
    put off iova freeing.

Signed-off-by: Zhen Lei <redacted>
---
  drivers/iommu/dma-iommu.c | 23 +++++++++++++++++++++++
  drivers/iommu/iommu.c     |  1 +
  include/linux/iommu.h     |  1 +
  3 files changed, 25 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index ddcbbdb..213e62a 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c

@@ -55,6 +55,7 @@ struct iommu_dma_cookie {
  	};
  	struct list_head		msi_page_list;
  	spinlock_t			msi_lock;
+	struct iommu_domain		*domain;
  };

  static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)

@@ -257,6 +258,17 @@ static int iova_reserve_iommu_regions(struct device *dev,
  	return ret;
  }

+static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad)
+{
+	struct iommu_dma_cookie *cookie;
+	struct iommu_domain *domain;
+
+	cookie = container_of(iovad, struct iommu_dma_cookie, iovad);
+	domain = cookie->domain;
+
+	domain->ops->flush_iotlb_all(domain);
+}
+
  /**
   * iommu_dma_init_domain - Initialise a DMA mapping domain
   * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()

@@ -308,6 +320,14 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
  	}

  	init_iova_domain(iovad, 1UL << order, base_pfn);
+
+	if (domain->non_strict) {
+		BUG_ON(!domain->ops->flush_iotlb_all);
+
+		cookie->domain = domain;

+		init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, NULL);
+	}
+
  	if (!dev)
  		return 0;

@@ -390,6 +410,9 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
  	/* The MSI case is only ever cleaning up its most recent allocation */
  	if (cookie->type == IOMMU_DMA_MSI_COOKIE)
  		cookie->msi_iova -= size;
+	else if (cookie->domain && cookie->domain->non_strict)

+		queue_iova(iovad, iova_pfn(iovad, iova),
+				size >> iova_shift(iovad), 0);
  	else
  		free_iova_fast(iovad, iova_pfn(iovad, iova),
  				size >> iova_shift(iovad));

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 63b3756..7811fde 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c

@@ -1263,6 +1263,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,

  	domain->ops  = bus->iommu_ops;
  	domain->type = type;
+	domain->non_strict = 0;
  	/* Assume all sizes by default; the driver may override this later */
  	domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee..0a0fb48 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h

@@ -88,6 +88,7 @@ struct iommu_domain_geometry {

  struct iommu_domain {
  	unsigned type;
+	int non_strict;