Re: [PATCH 01/11] iommu: Add device dma ownership set/release interfaces

Lu Baolu
2021-11-16T02:07:11Z

Hi Christoph,

On 11/15/21 9:14 PM, Christoph Hellwig wrote:
> 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.
>

Yeah! Sounds reasonable. I will make this in the next version.

Best regards,
baolu