iommufd: Move struct iommufd_object to public iommufd header

Prepare for an embedded structure design for driver-level iommufd_viommu
objects:
    // include/linux/iommufd.h
    struct iommufd_viommu {
        struct iommufd_object obj;
        ....
    };

    // Some IOMMU driver
    struct iommu_driver_viommu {
        struct iommufd_viommu core;
        ....
    };

It has to expose struct iommufd_object and enum iommufd_object_type from
the core-level private header to the public iommufd header.

Link: https://patch.msgid.link/r/54a43b0768089d690104530754f499ca05ce0074.1730836219.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 30f832a60ccb..22948dd03d67 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -8,6 +8,7 @@
 
 #include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/refcount.h>
 #include <linux/types.h>
 
 struct device;
@@ -18,6 +19,29 @@ struct iommufd_ctx;
 struct iommufd_device;
 struct page;
 
+enum iommufd_object_type {
+	IOMMUFD_OBJ_NONE,
+	IOMMUFD_OBJ_ANY = IOMMUFD_OBJ_NONE,
+	IOMMUFD_OBJ_DEVICE,
+	IOMMUFD_OBJ_HWPT_PAGING,
+	IOMMUFD_OBJ_HWPT_NESTED,
+	IOMMUFD_OBJ_IOAS,
+	IOMMUFD_OBJ_ACCESS,
+	IOMMUFD_OBJ_FAULT,
+#ifdef CONFIG_IOMMUFD_TEST
+	IOMMUFD_OBJ_SELFTEST,
+#endif
+	IOMMUFD_OBJ_MAX,
+};
+
+/* Base struct for all objects with a userspace ID handle. */
+struct iommufd_object {
+	refcount_t shortterm_users;
+	refcount_t users;
+	enum iommufd_object_type type;
+	unsigned int id;
+};
+
 struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
 					   struct device *dev, u32 *id);
 void iommufd_device_unbind(struct iommufd_device *idev);