Re: [PATCH] sparc: iommu/pci_sun4v: fix page alignment in dma mapping

[Stian Halseth]

Hi Leon,


On Tue, 2026-02-17 at 19:25 +0200, Leon Romanovsky wrote:
> 
> 
> On Tue, Feb 17, 2026, at 19:16, John Paul Adrian Glaubitz wrote:
> > Hi Stian,
> > 
> > On Tue, 2026-02-17 at 17:48 +0100, Stian Halseth wrote:
> > > Thanks for the review and suggestions.
> > > 
> > > On Tue, 2026-02-17 at 17:38 +0100, John Paul Adrian Glaubitz
> > > wrote:
> > > > Hi Stian,
> > > > 
> > > > please rephrase the subject to:
> > > > 
> > > >  sparc: Fix page alignment in dma mapping
> > > > 
> > > > Your patch is not specific to sun4v but also fixes generic
> > > > sparc
> > > > code,
> > > > so you should remove the part "iommu/pci_sun4v:" from the
> > > > subject.
> > > > 
> > > Understood — I will update the patch subject as suggested.
> > > > On Tue, 2026-02-17 at 17:21 +0100, stian@xxxxxx wrote:
> > > > > From: Stian Halseth <stian@xxxxxx>
> > > > > 
> > > > > 'phys' may include an offset within the page, while
> > > > > 'base_paddr' is
> > > > > already page-aligned.
> > > > > 
> > > > > This caused incorrect DMA mapping in dma_4u_map_phys and
> > > > > dma_4v_map_phys.
> > > > > 
> > > > > Fix both functions by masking phys with IO_PAGE_MASK or
> > > > > subtracting
> > > > > the page offset.
> > > > 
> > > > Please remove the newlines between your sentences, they're not
> > > > necessary
> > > > and also trim the lines at 80 columns.
> > > 
> > > Will do — I’ll reformat the commit message to 80-column lines
> > > and remove extra newlines.
> > 
> > Perfect! I have nothing to add. Let's have Andreas review your
> > patch ;-).
> 
> Please add Fixes line, so the patch will be taken to stable@ in
> automatic way.
I currently have:
Fixes: 38c0d0ebf520 ("sparc: Use physical address DMA mapping")

Is this sufficient, or do I need to add something else?
> 
> Thanks 
> 
> > 
> > Adrian
> > 
> > -- 
> >  .''`.  John Paul Adrian Glaubitz
> > : :' :  Debian Developer
> > `. `'   Physicist
> >   `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

-- 
Best regards
Stian Halseth
​