Re: [PATCH v2] fpga: dfl: afu: use PFN_DOWN() and PFN_PHYS() helper macros

From: Andy Shevchenko
Date: Tue Jun 27 2023 - 14:23:14 EST


On Tue, Jun 27, 2023 at 02:26:27PM +0800, Xu Yilun wrote:
> On 2023-06-19 at 15:56:34 -0400, Peter Colberg wrote:

...

> > - int npages = region->length >> PAGE_SHIFT;
> > + int npages = PFN_DOWN(region->length);
>
> I don't much prefer this change, it is not doing the phy addr to pfn
> convertion. The macro name doesn't match what is doing here.

This macro converts length to pages. And it's not about phy addr.

...

> > - long npages = region->length >> PAGE_SHIFT;
> > + long npages = PFN_DOWN(region->length);
>
> ditto

Ditto.

...

> > - int npages = region->length >> PAGE_SHIFT;
> > + int npages = PFN_DOWN(region->length);
>
> ditto

Ditto.

...

> > - offset = vma->vm_pgoff << PAGE_SHIFT;
> > + offset = PFN_PHYS(vma->vm_pgoff);
>
> ditto. The variables are offsets within file, not phys addr & pfn.

Here I probably can agree.

--
With Best Regards,
Andy Shevchenko