Re: [RFC PATCH 02/14] RISC-V: Add SBI STA extension definitions

Guo Ren
2023-08-03T01:28:13Z

On Wed, Apr 19, 2023 at 10:15:54AM +0200, Andrew Jones wrote:
> On Tue, Apr 18, 2023 at 07:43:51PM +0100, Conor Dooley wrote:
> > On Mon, Apr 17, 2023 at 12:33:50PM +0200, Andrew Jones wrote:
> > > The SBI STA extension enables steal-time accounting. Add the
> > > definitions it specifies.
> > >
> > > Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
> > > ---
> > > arch/riscv/include/asm/sbi.h | 15 +++++++++++++++
> > > 1 file changed, 15 insertions(+)
> > >
> > > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
> > > index 945b7be249c1..485b9ec20399 100644
> > > --- a/arch/riscv/include/asm/sbi.h
> > > +++ b/arch/riscv/include/asm/sbi.h
> > > @@ -30,6 +30,7 @@ enum sbi_ext_id {
> > > SBI_EXT_HSM = 0x48534D,
> > > SBI_EXT_SRST = 0x53525354,
> > > SBI_EXT_PMU = 0x504D55,
> > > + SBI_EXT_STA = 0x535441,
> >
> > What is the sort order of this? Matching the spec ordering, or just
> > append-at-the-end?
>
> I don't believe there's an established order. I've been going for spec
> order, I think.
>
> >
> > Unrelated, but in checking that I saw that your SUSP stuff is in
> > master - you planning on resending that series?
>
> I think I need to wait until it's been ratified.
Did you discuss the SBI_EXT_STA number of the SBI spec? Could you share
the link to me? Thx.

>
> >
> > Anyways, this does match the docs - but I'm quite hesitant to leave an
> > R-b when it's not merged yet.
>
> I could take your R-b now, and then if the spec changes, I'd drop it
> when reposting the PoC after reworking it.
>
> Thanks,
> drew
>
> >
> > Cheers,
> > Conor.
> >
> > >
> > > /* Experimentals extensions must lie within this range */
> > > SBI_EXT_EXPERIMENTAL_START = 0x08000000,
> > > @@ -236,6 +237,20 @@ enum sbi_pmu_ctr_type {
> > > /* Flags defined for counter stop function */
> > > #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
> > >
> > > +/* SBI STA (steal-time accounting) extension */
> > > +enum sbi_ext_sta_fid {
> > > + SBI_EXT_STA_SET_STEAL_TIME_SHMEM = 0,
> > > +};
> > > +
> > > +struct sbi_sta_struct {
> > > + __le32 sequence;
> > > + __le32 flags;
> > > + __le64 steal;
> > > + u8 preempted;
> > > + u8 pad[47];
> > > +} __packed;
> > > +
> > > +/* SBI spec version fields */
> > > #define SBI_SPEC_VERSION_DEFAULT 0x1
> > > #define SBI_SPEC_VERSION_MAJOR_SHIFT 24
> > > #define SBI_SPEC_VERSION_MAJOR_MASK 0x7f
> > > --
> > > 2.39.2
> > >
> > >
> > > _______________________________________________
> > > linux-riscv mailing list
> > > linux-riscv@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv
>
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv