[PATCH v4 05/23] iommufd/driver: Let iommufd_viommu_alloc helper save ictx to viommu->ictx

[Nicolin Chen <nicolinc@nvidia.com>]

When an IOMMU driver calls iommufd_viommu_alloc(), it must pass in an ictx
pointer as the underlying _iommufd_object_alloc() helper function requires
that to allocate a new object. However, neither the iommufd_viommu_alloc()
nor its underlying _iommufd_object_alloc() saves the ictx in the allocated
viommu object, although viommu could hold an ictx pointer.

When the IOMMU driver wants to use another iommufd function passing in the
allocated viommu, it could have avoided passing in the ictx pointer again,
if viommu->ictx is valid.

Save ictx to viommu->ictx in the iommufd_viommu_alloc(), in order to ease
a new vIOMMU-based helper that would then get the ictx from viommu->ictx.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 include/linux/iommufd.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 422eda95d19e..dc6535e848df 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -262,8 +262,10 @@ static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
 		static_assert(offsetof(drv_struct, member.obj) == 0);          \
 		ret = (drv_struct *)_iommufd_object_alloc(                     \
 			ictx, sizeof(drv_struct), IOMMUFD_OBJ_VIOMMU);         \
-		if (!IS_ERR(ret))                                              \
+		if (!IS_ERR(ret)) {                                            \
 			ret->member.ops = viommu_ops;                          \
+			ret->member.ictx = ictx;                               \
+		}                                                              \
 		ret;                                                           \
 	})
 
-- 
2.43.0