On Mon, Aug 14, 2023 at 12:52:34PM +0800, Baolu Lu wrote:

On 2023/8/3 8:07, Jason Gunthorpe wrote:

quoted

What exynos calls exynos_iommu_detach_device is actually putting the iommu
into identity mode.

Move to the new core support for ARM_DMA_USE_IOMMU by defining
ops->identity_domain.

Tested-by: Marek Szyprowski<m.szyprowski@samsung.com>
Acked-by: Marek Szyprowski<m.szyprowski@samsung.com>
Signed-off-by: Jason Gunthorpe<jgg@nvidia.com>
---
  drivers/iommu/exynos-iommu.c | 66 +++++++++++++++++-------------------
  1 file changed, 32 insertions(+), 34 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index c275fe71c4db32..5e12b85dfe8705 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c

@@ -24,6 +24,7 @@
  typedef u32 sysmmu_iova_t;
  typedef u32 sysmmu_pte_t;
+static struct iommu_domain exynos_identity_domain;

Is there a conflict between above and below?

No, this is a C forward declaration.

Jason