Re: [PATCH v6 02/10] hw/fsi: Introduce IBM's scratchpad

[Ninad Palsule]

Hello Philippe,

On 10/23/23 10:00, Philippe Mathieu-Daudé wrote:
> On 21/10/23 23:17, Ninad Palsule wrote:
> > This is a part of patchset where scratchpad is introduced.
> >
> > The scratchpad provides a set of non-functional registers. The firmware
> > is free to use them, hardware does not support any special management
> > support. The scratchpad registers can be read or written from LBUS
> > slave.
> >
> > In this model, The LBUS device is parent for the scratchpad.
> >
> > Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> > Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
> > ---
> > v2:
> > - Incorporated Joel's review comments.
> > v5:
> > - Incorporated review comments by Cedric.
> > v6:
> > - Incorporated review comments by Daniel.
> > ---
> >   meson.build                        |  1 +
> >   hw/fsi/trace.h                     |  1 +
> >   include/hw/fsi/engine-scratchpad.h | 32 ++++++++++
> >   include/hw/fsi/fsi.h               | 16 +++++
> >   hw/fsi/engine-scratchpad.c         | 93 ++++++++++++++++++++++++++++++
> >   hw/fsi/Kconfig                     |  4 ++
> >   hw/fsi/meson.build                 |  1 +
> >   hw/fsi/trace-events                |  2 +
> >   8 files changed, 150 insertions(+)
> >   create mode 100644 hw/fsi/trace.h
> >   create mode 100644 include/hw/fsi/engine-scratchpad.h
> >   create mode 100644 include/hw/fsi/fsi.h
> >   create mode 100644 hw/fsi/engine-scratchpad.c
> >   create mode 100644 hw/fsi/trace-events
>
>
> > diff --git a/include/hw/fsi/fsi.h b/include/hw/fsi/fsi.h
> > new file mode 100644
> > index 0000000000..e65f26f17b
> > --- /dev/null
> > +++ b/include/hw/fsi/fsi.h
> > @@ -0,0 +1,16 @@
> > +/*
> > + * SPDX-License-Identifier: GPL-2.0-or-later
> > + * Copyright (C) 2023 IBM Corp.
> > + *
> > + * IBM Flexible Service Interface
> > + */
> > +#ifndef FSI_FSI_H
> > +#define FSI_FSI_H
> > +
> > +/* Bitwise operations at the word level. */
> > +#define BE_BIT(x)                          BIT(31 - (x))
> > +#define GENMASK(t, b) \
> > +    (((1ULL << ((t) + 1)) - 1) & ~((1ULL << (b)) - 1))
>
> Please use MAKE_64BIT_MASK() from "qemu/bitops.h".

The GENMASK and MAKE_64BIT_MASK macros are invoke differently.

GENMASK is invoked with bit t and bit b (t:b) and it provides the mask and

MAKE_64BIT_MASK uses shift and length.

Thanks for the review.

Regards,

Ninad


> > +#define BE_GENMASK(t, b)                   GENMASK(BE_BIT(t), 
> > BE_BIT(b))
> > +
> > +#endif