On Sun, Feb 2, 2025 at 10:47 PM Richard Henderson
<richard.hender...@linaro.org> wrote:
>
> On 1/31/25 13:44, Artyom Tarasenko wrote:
> > fake access to
> > PCR Performance Control Register
> > and
> > PIC Performance Instrumentation Counter.
> >
> > Ignore writes in privileged mode, and return 0 on reads.
> >
> > This allows booting Tribblix, MilaX and v9os under Niagara target.
> >
> > Signed-off-by: Artyom Tarasenko <atar4q...@gmail.com>
> > ---
> > target/sparc/insns.decode | 7 ++++++-
> > target/sparc/translate.c | 20 ++++++++++++++++++++
> > 2 files changed, 26 insertions(+), 1 deletion(-)
> >
> > diff --git a/target/sparc/insns.decode b/target/sparc/insns.decode
> > index 989c20b44a..504147563c 100644
> > --- a/target/sparc/insns.decode
> > +++ b/target/sparc/insns.decode
> > @@ -96,7 +96,10 @@ CALL 01 i:s30
> > RDTICK 10 rd:5 101000 00100 0 0000000000000
> > RDPC 10 rd:5 101000 00101 0 0000000000000
> > RDFPRS 10 rd:5 101000 00110 0 0000000000000
> > - RDASR17 10 rd:5 101000 10001 0 0000000000000
> > + {
> > + RDASR17 10 rd:5 101000 10001 0 0000000000000
> > + RDPIC 10 rd:5 101000 10001 0 0000000000000
> > + }
> > RDGSR 10 rd:5 101000 10011 0 0000000000000
> > RDSOFTINT 10 rd:5 101000 10110 0 0000000000000
> > RDTICK_CMPR 10 rd:5 101000 10111 0 0000000000000
> > @@ -114,6 +117,8 @@ CALL 01 i:s30
> > WRCCR 10 00010 110000 ..... . ............. @n_r_ri
> > WRASI 10 00011 110000 ..... . ............. @n_r_ri
> > WRFPRS 10 00110 110000 ..... . ............. @n_r_ri
> > + WRPCR 10 10000 110000 01000 0 0000000000000
> > + WRPIC 10 10001 110000 01000 0 0000000000000
> > {
> > WRGSR 10 10011 110000 ..... . ............. @n_r_ri
> > WRPOWERDOWN 10 10011 110000 ..... . ............. @n_r_ri
> > diff --git a/target/sparc/translate.c b/target/sparc/translate.c
> > index 7e5c7351cb..285c9b0a59 100644
> > --- a/target/sparc/translate.c
> > +++ b/target/sparc/translate.c
> > @@ -2882,6 +2882,15 @@ static TCGv do_rd_leon3_config(DisasContext *dc,
> > TCGv dst)
> >
> > TRANS(RDASR17, ASR17, do_rd_special, true, a->rd, do_rd_leon3_config)
> >
> > +static TCGv do_rdpic(DisasContext *dc, TCGv dst)
> > +{
> > + tcg_gen_movi_tl(dst, 0UL);
> > + return dst;
> > +}
>
> return tcg_constant_tl(0);
>
> > +
> > +TRANS(RDPIC, HYPV, do_rd_special, true, a->rd, do_rdpic)
>
> Surely reads are not allowed in user mode.
Thanks Richard, addressed it in v2.
