iommufd: Put constants for all the uAPI enums

Relying on position in the enum makes it subtly harder when doing merge
resolutions or backporting as it is easy to grab a patch and not notice it
is a uAPI change with a differently ordered enum. This may become a bigger
problem in next cycles when iommu_hwpt_invalidate_data_type and other
per-driver enums have patches flowing through different trees.

So lets start including constants for all the uAPI enums to make this
safer.

No functional change.

Link: https://lore.kernel.org/r/0-v1-2c06ec044924+133-iommufd_uapi_const_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: jgunthorpe

include/uapi/linux/iommufd.h

@@ -37,20 +37,20 @@
 enum {
 	IOMMUFD_CMD_BASE = 0x80,
 	IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE,
-	IOMMUFD_CMD_IOAS_ALLOC,
-	IOMMUFD_CMD_IOAS_ALLOW_IOVAS,
-	IOMMUFD_CMD_IOAS_COPY,
-	IOMMUFD_CMD_IOAS_IOVA_RANGES,
-	IOMMUFD_CMD_IOAS_MAP,
-	IOMMUFD_CMD_IOAS_UNMAP,
-	IOMMUFD_CMD_OPTION,
-	IOMMUFD_CMD_VFIO_IOAS,
-	IOMMUFD_CMD_HWPT_ALLOC,
-	IOMMUFD_CMD_GET_HW_INFO,
-	IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING,
-	IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP,
-	IOMMUFD_CMD_HWPT_INVALIDATE,
-	IOMMUFD_CMD_FAULT_QUEUE_ALLOC,
+	IOMMUFD_CMD_IOAS_ALLOC = 0x81,
+	IOMMUFD_CMD_IOAS_ALLOW_IOVAS = 0x82,
+	IOMMUFD_CMD_IOAS_COPY = 0x83,
+	IOMMUFD_CMD_IOAS_IOVA_RANGES = 0x84,
+	IOMMUFD_CMD_IOAS_MAP = 0x85,
+	IOMMUFD_CMD_IOAS_UNMAP = 0x86,
+	IOMMUFD_CMD_OPTION = 0x87,
+	IOMMUFD_CMD_VFIO_IOAS = 0x88,
+	IOMMUFD_CMD_HWPT_ALLOC = 0x89,
+	IOMMUFD_CMD_GET_HW_INFO = 0x8a,
+	IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING = 0x8b,
+	IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP = 0x8c,
+	IOMMUFD_CMD_HWPT_INVALIDATE = 0x8d,
+	IOMMUFD_CMD_FAULT_QUEUE_ALLOC = 0x8e,
 };
 
 /**
@@ -400,8 +400,8 @@ struct iommu_hwpt_vtd_s1 {
  * @IOMMU_HWPT_DATA_VTD_S1: Intel VT-d stage-1 page table
  */
 enum iommu_hwpt_data_type {
-	IOMMU_HWPT_DATA_NONE,
-	IOMMU_HWPT_DATA_VTD_S1,
+	IOMMU_HWPT_DATA_NONE = 0,
+	IOMMU_HWPT_DATA_VTD_S1 = 1,
 };
 
 /**
@@ -491,8 +491,8 @@ struct iommu_hw_info_vtd {
  * @IOMMU_HW_INFO_TYPE_INTEL_VTD: Intel VT-d iommu info type
  */
 enum iommu_hw_info_type {
-	IOMMU_HW_INFO_TYPE_NONE,
-	IOMMU_HW_INFO_TYPE_INTEL_VTD,
+	IOMMU_HW_INFO_TYPE_NONE = 0,
+	IOMMU_HW_INFO_TYPE_INTEL_VTD = 1,
 };
 
 /**
@@ -629,7 +629,7 @@ struct iommu_hwpt_get_dirty_bitmap {
  * @IOMMU_HWPT_INVALIDATE_DATA_VTD_S1: Invalidation data for VTD_S1
  */
 enum iommu_hwpt_invalidate_data_type {
-	IOMMU_HWPT_INVALIDATE_DATA_VTD_S1,
+	IOMMU_HWPT_INVALIDATE_DATA_VTD_S1 = 0,
 };
 
 /**
@@ -768,7 +768,7 @@ struct iommu_hwpt_pgfault {
  */
 enum iommufd_page_response_code {
 	IOMMUFD_PAGE_RESP_SUCCESS = 0,
-	IOMMUFD_PAGE_RESP_INVALID,
+	IOMMUFD_PAGE_RESP_INVALID = 1,
 };
 
 /**