linux-kernel - Re: [PATCH 1/2] riscv: Correct the initialized flow of FP register

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Message-ID: <CABvJ_xgHVT4QKAxRPdLQp3Q5bTmjQ5QfTo6R49Z0Qwatuc_b+A@mail.gmail.com>
Date:   Wed, 14 Aug 2019 09:45:36 +0800
From:   Vincent Chen <vincent.chen@...ive.com>
To:     Paul Walmsley <paul.walmsley@...ive.com>,
        Anup Patel <anup@...infault.org>
Cc:     Palmer Dabbelt <palmer@...ive.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        linux-riscv <linux-riscv@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org List" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] riscv: Correct the initialized flow of FP register

On Thu, Aug 8, 2019 at 11:50 PM Paul Walmsley <paul.walmsley@...ive.com> wrote:
>
> On Thu, 8 Aug 2019, Anup Patel wrote:
>
> > On Thu, Aug 8, 2019 at 1:30 PM Vincent Chen <vincent.chen@...ive.com> wrote:
> > >
> > > +static inline void fstate_off(struct task_struct *task,
> > > +                              struct pt_regs *regs)
> > > +{
> > > +       regs->sstatus = (regs->sstatus & ~(SR_FS)) | SR_FS_OFF;
> >
> > The SR_FS_OFF is 0x0 so no need for ORing it.
>
> That one looks OK to me, since it makes it more obvious to humans what's
> happening here - reviewers won't need to know that "off" is 0x0.  The
> compiler should drop it internally, so it won't affect the generated
> code.
>
Thanks for Paul's comment
My thought is the same as Paul.


> > Apart from above minor comment, looks good to me.
> >
> > Reviewed-by: Anup Patel <anup@...infault.org>
>
> Will add your Reviewed-by: tag - let us know if you want me to drop it or
> caveat it.
>
>
> - Paul

Dear Anup,
I suppose you can accept our thought about using the SR_FS_OFF flag
because I didn't receive any reply from you.
Thanks for your review and comments.

Regards,
Vincent