From: Andrew Jones <ajones@ventanamicro.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: 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 13:46:31 +0100 [thread overview]
Message-ID: <20230322124631.7p67thzeblrawsqj@orel> (raw)
In-Reply-To: <20230322120907.2968494-1-Jason@zx2c4.com>
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>
> 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.)
Thanks,
drew
next prev parent reply other threads:[~2023-03-22 12:46 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 [this message]
2023-03-22 15:17 ` Conor Dooley
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=20230322124631.7p67thzeblrawsqj@orel \
--to=ajones@ventanamicro.com \
--cc=Jason@zx2c4.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).