From: Conor Dooley <conor@kernel.org>
To: Andrew Jones <ajones@ventanamicro.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.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
Subject: Re: [PATCH] riscv: require alternatives framework when selecting FPU support
Date: Wed, 22 Mar 2023 15:17:13 +0000 [thread overview]
Message-ID: <1884bd96-2783-4556-bc57-8b733758baff@spud> (raw)
In-Reply-To: <20230322124631.7p67thzeblrawsqj@orel>
[-- Attachment #1: Type: text/plain, Size: 1932 bytes --]
On Wed, Mar 22, 2023 at 01:46:31PM +0100, Andrew Jones wrote:
> On Wed, Mar 22, 2023 at 01:09:07PM +0100, Jason A. Donenfeld wrote:
> > When moving switch_to's has_fpu() over to using riscv_has_extension_
> > likely() rather than static branchs, the FPU code gained a dependency on
> > the alternatives framework. If CONFIG_RISCV_ALTERNATIVE isn't selected
> > when CONFIG_FPU is, then has_fpu() returns false, and switch_to does not
> > work as intended. So select CONFIG_RISCV_ALTERNATIVE when CONFIG_FPU is
> > selected.
> >
> > Fixes: 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()")
> > Link: https://lore.kernel.org/all/ZBruFRwt3rUVngPu@zx2c4.com/
> > Cc: Jisheng Zhang <jszhang@kernel.org>
> > Cc: Andrew Jones <ajones@ventanamicro.com>
> > Cc: Heiko Stuebner <heiko@sntech.de>
> > Cc: Conor Dooley <conor.dooley@microchip.com>
Thanks for fixing it!
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> > ---
> > arch/riscv/Kconfig | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index c5e42cc37604..0f59350c699d 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -467,6 +467,7 @@ config TOOLCHAIN_HAS_ZIHINTPAUSE
> > config FPU
> > bool "FPU support"
> > default y
> > + select RISCV_ALTERNATIVE
> > help
> > Say N here if you want to disable all floating-point related procedure
> > in the kernel.
> > --
> > 2.40.0
> >
>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
>
> I took a look to see if we missed anything else and see that we should
> do the same patch for KVM. I'll send one.
>
> (It's tempting to just select RISCV_ALTERNATIVE from RISCV, but maybe we
> can defer that wedding a bit longer.)
At that point, the config option should just go away entirely, no?
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
next prev parent reply other threads:[~2023-03-22 15:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20230128172856.3814-1-jszhang@kernel.org>
[not found] ` <20230128172856.3814-7-jszhang@kernel.org>
2023-03-22 12:01 ` [PATCH v5 06/13] riscv: fpu: switch has_fpu() to riscv_has_extension_likely() Jason A. Donenfeld
2023-03-22 12:09 ` [PATCH] riscv: require alternatives framework when selecting FPU support Jason A. Donenfeld
2023-03-22 12:46 ` Andrew Jones
2023-03-22 15:17 ` Conor Dooley [this message]
2023-03-22 19:26 ` Andrew Jones
2023-03-22 19:44 ` Conor Dooley
2023-03-22 20:05 ` Conor Dooley
2023-03-22 20:19 ` Jason A. Donenfeld
2023-03-23 14:49 ` Conor Dooley
2023-03-23 15:56 ` Jason A. Donenfeld
2023-03-23 22:19 ` Conor Dooley
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1884bd96-2783-4556-bc57-8b733758baff@spud \
--to=conor@kernel.org \
--cc=Jason@zx2c4.com \
--cc=ajones@ventanamicro.com \
--cc=anup@brainfault.org \
--cc=aou@eecs.berkeley.edu \
--cc=atishp@atishpatra.org \
--cc=conor.dooley@microchip.com \
--cc=heiko@sntech.de \
--cc=jszhang@kernel.org \
--cc=kvm-riscv@lists.infradead.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=regressions@leemhuis.info \
--cc=regressions@lists.linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).