[Linaro-mm-sig] Re: [PATCH 8/9] iommufd: Accept a DMABUF through IOMMU_IOAS_MAP_FILE

On Thu, Nov 13, 2025 at 04:05:09PM -0800, Nicolin Chen wrote:

...

-struct iopt_pages *iopt_alloc_file_pages(struct file *file, unsigned long start, +struct iopt_pages *iopt_alloc_file_pages(struct file *file,

• 			 unsigned long start_byte,
  

• 			 unsigned long start,
  		 unsigned long length, bool writable);
  

Passing in start_byte looks like a cleanup to me, aligning with what iopt_map_common() has.

Since we are doing this cleanup, maybe we could follow the same sequence: xxx, start, length, start_byte, writable?

??

static int iopt_map_common(struct iommufd_ctx *ictx, struct io_pagetable *iopt, struct iopt_pages *pages, unsigned long *iova, unsigned long length, unsigned long start_byte, int iommu_prot, unsigned int flags)

Not the same arguments, we don't pass start and start_byte there?

Jason