On Fri, Jun 28, 2024 at 09:31:56AM -0400, Eric Farman wrote:
> > > dma32_to_u32(ccw->cda) - ccw_head;
> > > - ccw->cda = u32_to_dma32(cda);
> > > + /* Calculate offset of TIC target */
> > > + cda = dma32_to_u32(ccw->cda) - ccw_head;
> > > + ccw->cda = virt_to_dma32(iter->ch_ccw) +
> > > cda;
> >
> > I would suggest to rename cda to "offset", since that reflects what
> > it is
> > now. Also this code needs to take care of type checking, which will
> > fail now
> > due to dma32_t type (try "make C=1 drivers/s390/cio/vfio_ccw_cp.o).
...
> I was poking at that code yesterday because it seemed suspect, but as I
> wasn't getting an explicit failure (versus the CPC generated by hw), I
> opted to leave it for now. I agree they should both be fixed up.
...
> > I guess
> > you could add this hunk to your patch:
> >
> > @@ -915,7 +915,7 @@ void cp_update_scsw(struct channel_program *cp,
> > union scsw *scsw)
> > * in the ioctl directly. Path status changes etc.
> > */
> > list_for_each_entry(chain, &cp->ccwchain_list, next) {
> > - ccw_head = (u32)(u64)chain->ch_ccw;
> > + ccw_head = (__force u32)virt_to_dma32(chain-
> > >ch_ccw);
> > /*
> > * On successful execution, cpa points just beyond
> > the end
> > * of the chain.
...
> > Furthermore it looks to me like the ch_iova member of struct ccwchain
> > should
> > get a dma32_t type instead of u64. The same applies to quite a few
> > variables
> > to the code.
>
> Agreed. I started this some time back after the IDAW code got reworked,
> but have been sidetracked. The problem with ch_iova is more apparent
> after the dma32 stuff.
>
> > I could give this a try, but I think it would be better if
> > somebody who knows what he is doing would address this :)
>
> I'll finish them up. But v2 will have to wait until after my holiday.
> Thanks for reminding me of the typechecking!
I hope you didn't get me wrong: from my point of view we want one or
two small patches (the above hunks), which fix the bugs, if you
agree.
And then address the type checking stuff at a later point in time.
(btw: your mailer adds lot's of extra line wraps)
