On Mon, Nov 15, 2021 at 10:05:42AM +0800, Lu Baolu wrote:
> +enum iommu_dma_owner {
> + DMA_OWNER_NONE,
> + DMA_OWNER_KERNEL,
> + DMA_OWNER_USER,
> +};
> +
> + enum iommu_dma_owner dma_owner;
> + refcount_t owner_cnt;
> + struct file *owner_user_file;
I'd just overload the ownership into owner_user_file,
NULL -> no owner
(struct file *)1UL) -> kernel
real pointer -> user
Which could simplify a lot of the code dealing with the owner.
