Re: [jgunthorpe:smmuv3_nesting 11/17] drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c:141:21: sparse: sparse: incorrect type in assignment (different base types)

[Nicolin Chen <nicolinc@nvidia.com>]

On Mon, Oct 21, 2024 at 09:41:25AM -0300, Jason Gunthorpe wrote:

> >  arm_vsmmu_convert_user_cmd(struct arm_vsmmu *vsmmu,
> > -                          struct iommu_viommu_arm_smmuv3_invalidate *cmd)
> > +                          struct vsmmu_invalidation_cmd *cmd)
> >  {
> >         cmd->cmd[0] = le64_to_cpu(cmd->cmd[0]);
> >         cmd->cmd[1] = le64_to_cpu(cmd->cmd[1]);
> 
> That's going to make spare complain here though :\
> 
> You need a union to quiet it.. Or probably just a __force and a
> comment is fine

Oh, right... I did __force, and confirmed with sparse:
-       cmd->cmd[0] = le64_to_cpu(cmd->cmd[0]);
-       cmd->cmd[1] = le64_to_cpu(cmd->cmd[1]);
+       /* Commands are le64 stored in u64 */
+       cmd->cmd[0] = le64_to_cpu((__force __le64)cmd->cmd[0]);
+       cmd->cmd[1] = le64_to_cpu((__force __le64)cmd->cmd[1]);

Thanks
Nicolin