Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <ZBruFRwt3rUVngPu@zx2c4.com> <20230322120907.2968494-1-Jason@zx2c4.com>
 <20230322124631.7p67thzeblrawsqj@orel> <1884bd96-2783-4556-bc57-8b733758baff@spud>
 <20230322192610.sad42xau33ye5ayn@orel> <2a3b08ce-5ab1-41b6-ad58-edbeff7b1acb@spud>
 <ad445951-3d13-4644-94d9-e0989cda39c3@spud>
In-Reply-To: <ad445951-3d13-4644-94d9-e0989cda39c3@spud>
From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
Date:   Wed, 22 Mar 2023 21:19:50 +0100
Message-ID: <CAHmME9qEbUP7cq-iofN=ruSWhsHUva+qqavfEpNzDK_BjQVqxw@mail.gmail.com>
Subject: Re: [PATCH] riscv: require alternatives framework when selecting FPU support
To:     Conor Dooley <conor@kernel.org>
Cc:     Andrew Jones <ajones@ventanamicro.com>,
        Jisheng Zhang <jszhang@kernel.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Conor Dooley <conor.dooley@microchip.com>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
        regressions@leemhuis.info, regressions@lists.linux.dev
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Wed, Mar 22, 2023 at 9:05=E2=80=AFPM Conor Dooley <conor@kernel.org> wro=
te:
>
> On Wed, Mar 22, 2023 at 07:44:13PM +0000, Conor Dooley wrote:
> > On Wed, Mar 22, 2023 at 08:26:10PM +0100, Andrew Jones wrote:
> > > On Wed, Mar 22, 2023 at 03:17:13PM +0000, Conor Dooley wrote:
> > > > On Wed, Mar 22, 2023 at 01:46:31PM +0100, Andrew Jones wrote:
> >
> > > > > (It's tempting to just select RISCV_ALTERNATIVE from RISCV, but m=
aybe we
> > > > >  can defer that wedding a bit longer.)
> > > >
> > > > At that point, the config option should just go away entirely, no?
> > >
> > > Ah, yes, and that makes the idea even more attractive, as we could re=
move
> > > several ifdefs.
> >
> > I went and did the cursory check, it's not compatible with XIP_KERNEL s=
o
> > dropping the option entirely probably isn't a possibility :/
>
> What I said is only now sinking in. We're now going to be disabling FPU
> support on XIP kernels with this patch.
> Well, technically not this patch since it wouldn't have built without
> Jason's changes, but that doesn't seem like the right thing to do...

I suppose you could have riscv_has_extension_*() fall back to
something that doesn't use alternatives on XIP kernels.