Re: git: 60381fd1ee86 - main - memdesc: Retire MEMDESC_CCB.

On Mon, Jul 17, 2023 at 11:15 AM John Baldwin <jhb@freebsd.org> wrote:

> On 7/17/23 8:48 AM, Konstantin Belousov wrote:
> > On Fri, Jul 14, 2023 at 06:41:03PM +0000, John Baldwin wrote:
> >> The branch main has been updated by jhb:
> >>
> >> URL:
> https://cgit.FreeBSD.org/src/commit/?id=60381fd1ee8668ea1e4676a6128883d987cab858
> >>
> >> commit 60381fd1ee8668ea1e4676a6128883d987cab858
> >> Author:     John Baldwin <jhb@FreeBSD.org>
> >> AuthorDate: 2023-07-14 18:30:31 +0000
> >> Commit:     John Baldwin <jhb@FreeBSD.org>
> >> CommitDate: 2023-07-14 18:32:16 +0000
> >>
> >>      memdesc: Retire MEMDESC_CCB.
> >>
> >>      Instead, change memdesc_ccb to examine the CCB and return a
> memdesc of
> >>      a more generic type describing the data buffer.
> >
> >> diff --git a/sys/kern/subr_bus_dma.c b/sys/kern/subr_bus_dma.c
> >> index 65a08aeba17c..bfaad30b37d3 100644
> >> --- a/sys/kern/subr_bus_dma.c
> >> +++ b/sys/kern/subr_bus_dma.c
> >> @@ -304,94 +304,6 @@ bus_dmamap_load_ma_triv(bus_dma_tag_t dmat,
> bus_dmamap_t map,
> >> @@ -566,49 +478,18 @@ bus_dmamap_load_ccb(bus_dma_tag_t dmat,
> bus_dmamap_t map, union ccb *ccb,
> >> +    mem = memdesc_ccb(ccb);
> >> +    return (bus_dmamap_load_mem(dmat, map, &mem, callback,
> callback_arg,
> >> +        flags));
> >>   }
> > This makes kernel not linkable if CAM is not included into it.
>
> Hmmm, ok.  I can either move the memdesc_ccb routine into sys/kern
> somewhere
> (like the kern_memdesc.c file in my other pending review), or we can #ifdef
> this function.  It probably doesn't make sense to have a
> bus_dmamap_load_ccb
> if you don't have CAM, so I think I prefer the second option.
>

MINIMAL doesn't have CAM configured, but it is loadable as a module.

I'd think we'd want a dummy one fo these with weak symbol binding and have
the actual
one live in cam somewhere that overrides this  symbol.

I just hit this in building MINIMAL for other reasons....

Warner