Re: [PATCH V3 14/22] LoongArch: Add signal handling support

From: Huacai Chen
Date: Tue Sep 21 2021 - 22:43:26 EST


Hi, Richard,

On Tue, Sep 21, 2021 at 5:14 AM Richard Henderson <rth@xxxxxxxxxxx> wrote:
>
> On 9/19/21 7:36 PM, Huacai Chen wrote:
> > Hi, Arnd,
> >
> > On Sun, Sep 19, 2021 at 5:59 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >>
> >> On Sat, Sep 18, 2021 at 9:12 AM Huacai Chen <chenhuacai@xxxxxxxxx> wrote:
> >>> On Sat, Sep 18, 2021 at 5:10 AM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:
> >>>> For example does LoongArch have a version without built in floating
> >>>> point support?
> >>>
> >>> Some of these structures seems need rethinking, But we really have
> >>> LoongArch-based MCUs now (no FP, no SMP, and even no MMU).
> >>
> >> NOMMU Linux is kind-of on the way out as interest is fading, so I hope you
> >> don't plan on supporting this in the future.
> >>
> >> Do you expect to see future products with MMU but no FP or no SMP?
> > OK, we will not care no-MMU hardware in Linux, but no-FP and no-SMP
> > hardware will be supported.
>
> Please consider requiring the FP registers to be present even on no-FP hardware.
>
> With this plus the FP data movement instructions (FMOV, MOVGR2FR, MOVFR2GR, FLD, FST), it
> is possible to implement soft-float without requiring a separate soft-float ABI. This can
> vastly simplify compatibility and deployment.
OK, I'll send an updated version.

>
>
> r~