On Tue, 5 Sep 2023 15:56:39 +0100
Jonathan Cameron via <qemu-devel@nongnu.org> wrote:
> On Mon, 4 Sep 2023 20:26:59 +0200
> Philippe Mathieu-Daudé <phi...@linaro.org> wrote:
>
> > On 4/9/23 18:47, Jonathan Cameron wrote:
> > > As an encoded version of these key configuration parameters is
> > > a register, provide functions to extract it again so as to avoid
> > > the need for duplicating the storage.
> > >
> > > Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com>
> > > ---
> > > include/hw/cxl/cxl_component.h | 14 ++++++++++++++
> > > hw/cxl/cxl-component-utils.c | 17 +++++++++++++++++
> > > 2 files changed, 31 insertions(+)
> > >
> > > diff --git a/include/hw/cxl/cxl_component.h
> > > b/include/hw/cxl/cxl_component.h
> > > index 42c7e581a7..f0ad9cf7de 100644
> > > --- a/include/hw/cxl/cxl_component.h
> > > +++ b/include/hw/cxl/cxl_component.h
> > > @@ -238,7 +238,21 @@ static inline int cxl_decoder_count_enc(int count)
> > > return 0;
> > > }
> > >
> > > +static inline int cxl_decoder_count_dec(int enc_cnt)
> > > +{
> > > + switch (enc_cnt) {
> > > + case 0: return 1;
> > > + case 1: return 2;
> > > + case 2: return 4;
> > > + case 3: return 6;
> > > + case 4: return 8;
> > > + case 5: return 10;
> > > + }
> > > + return 0;
> > > +}
> >
> > Why inline?
> >
>
> Bad habit.
Nope. I'm being slow. This is in a header so if I don't
mark it inline I get a bunch of defined but not used warnings.
Obviously I could move the implementation of this and the matching
encoding routines out of the header. I haven't done so for now.
>
>
> > Alternatively:
> >
> > unsigned cxl_decoder_count_dec(unsigned enc_cnt)
> > {
> > return enc_cnt <= 5 ? 2 * enc_cnt : 0;
>
> It gets a little more fiddly than the code I'm proposing implies.
> For Switches and Host Bridges larger values are defined
> (we just don't emulate them yet and may never do so) and those
> don't have a sensible mapping.
>
> I guess there is no harm in adding the full decode however
> which will make it more obvious why it was a switch statement.
>
> > }
> >
> >
>
>
>
