From: Nathan Chancellor <natechancellor@gmail.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Peter Smith <Peter.Smith@arm.com>, Stefan Agner <stefan@agner.ch>,
David Howells <dhowells@redhat.com>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
Manoj Gupta <manojgupta@google.com>,
Benjamin Gaignard <benjamin.gaignard@linaro.org>,
"Joel Fernandes \(Google\)" <joel@joelfernandes.org>,
Jian Cai <caij2003@gmail.com>,
clang-built-linux <clang-built-linux@googlegroups.com>,
Ilie Halip <ilie.halip@gmail.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Russell King <linux@armlinux.org.uk>,
Krzysztof Kozlowski <krzk@kernel.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Sami Tolvanen <samitolvanen@google.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Arnd Bergmann <arnd@arndb.de>,
"Steven Rostedt \(VMware\)" <rostedt@goodmis.org>,
Jian Cai <jiancai@google.com>,
Doug Anderson <armlinux@m.disordat.com>,
Dan Williams <dan.j.williams@intel.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Patrick Bellasi <patrick.bellasi@arm.com>,
Masami Hiramatsu <mhiramat@kernel.org>, Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain
Date: Thu, 9 Apr 2020 17:12:01 -0700 [thread overview]
Message-ID: <20200410001201.GA15303@ubuntu-s3-xlarge-x86> (raw)
In-Reply-To: <CAKwvOdkot0Q7FSCMKGm6ti4hhvD3N+AMUK4Xv2Xxiiu3+pURgQ@mail.gmail.com>
On Thu, Apr 09, 2020 at 05:01:33PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote:
> On Thu, Apr 9, 2020 at 4:28 PM Jian Cai <caij2003@gmail.com> wrote:
> >
> > iwmmxt.S contains XScale instructions LLVM ARM backend does not support.
> > Skip this file if LLVM integrated assemmbler or LLD is used to build ARM
>
> Hi Jian, thank you for the patch. It's pretty much spot on for what I
> was looking for. Some notes below:
>
> s/assemmbler/assembler
>
> :set spell
>
> ;)
>
> Also, could use a link tag, ie.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/975
>
> (Always include the link tag to help us track when and where patches land).
>
> Finally, I think the hunks for the two different files should be
> split; the init/Kconfig change should be it's own dedicated change
> that goes to Masahiro, the maintainer of the Kbuild tree. Then when
> we have that, the dependent configs should go separately. Would you
> mind splitting this patch in two, and re-sending just the Kbuild patch
> for now? Since you used Sami's patch for inspiration
> (https://github.com/ClangBuiltLinux/linux/issues/975#issuecomment-611694153,
> https://github.com/samitolvanen/linux/commit/fe9786cb52a0100273c75117dcea8b8e07006fde),
> it would be polite to Sami to add a tag like:
>
> Suggested-by: Sami Tolvanen <samitolvanen@google.com>
>
> or maybe better yet, take Sami's patch, add your signed off by tag
> (maintaining him as the git author, see `git log --pretty=fuller`),
> then rebase your AS_IS_CLANG hunk on top, make that a second patch,
> then finally have the arm change as a third patch.
>
> This change is exactly what I'm looking for, so these are just process concerns.
I think that they can be sent as a series that is picked up by Masahiro
with an ack from an ARM maintainer.
> > kernel.
> >
> > Signed-off-by: Jian Cai <caij2003@gmail.com>
> > ---
> > arch/arm/Kconfig | 2 +-
> > init/Kconfig | 6 ++++++
> > 2 files changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index 66a04f6f4775..39de8fc64a73 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -804,7 +804,7 @@ source "arch/arm/mm/Kconfig"
> >
> > config IWMMXT
> > bool "Enable iWMMXt support"
> > - depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
> > + depends on !AS_IS_CLANG && !LD_IS_LLD && (CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B)
> > default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
> > help
> > Enable support for iWMMXt context switching at run time if
> > diff --git a/init/Kconfig b/init/Kconfig
> > index 1c12059e0f7e..b0ab3271e900 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -19,6 +19,12 @@ config GCC_VERSION
> > config CC_IS_CLANG
> > def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
> >
> > +config AS_IS_CLANG
> > + def_bool $(success,$(AS) --version | head -n 1 | grep -q clang)
$(AS) is being replaced with $(LLVM_IAS). That line should be:
def_bool $(success,test $(LLVM_IAS) -eq 1)
I think. That depends on a commit in Masahiro's for-next branch [1] so
it should be based/tested against that.
Otherwise, I agree with Nick's comment about being split into two
patches (one for the init/Kconfig change and one for the ARM change) and
adding the Link tag.
I ran about 75 randconfigs with LD=ld.lld and LLVM_IAS=1 and I did not
see any Kconfig warnings from this and CONFIG_IWMMXT was unset in every
one. Should prevent the errors that you encountered. Feel free to apply
the following tags to any follow up revisions.
Tested-by: Nathan Chancellor <natechancellor@gmail.com> # randconfig
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git
> > +config LD_IS_LLD
> > + def_bool $(success,$(LD) --version | head -n 1 | grep -q LLD)
> > +
> > config CLANG_VERSION
> > int
> > default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
> > --
>
> --
> Thanks,
> ~Nick Desaulniers
>
Cheers,
Nathan
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next prev parent reply other threads:[~2020-04-10 0:12 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-09 23:27 [PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain Jian Cai
2020-04-10 0:01 ` Nick Desaulniers
2020-04-10 0:12 ` Nathan Chancellor [this message]
2020-04-10 6:38 ` Sedat Dilek
2020-04-10 7:44 ` Nathan Chancellor
2020-04-10 9:56 ` Arnd Bergmann
2020-04-10 11:15 ` Ard Biesheuvel
2020-04-10 12:33 ` Russell King - ARM Linux admin
2020-04-10 13:09 ` Ard Biesheuvel
2020-04-13 20:45 ` Nick Desaulniers
2020-04-14 8:59 ` Ard Biesheuvel
2020-04-14 18:38 ` Nick Desaulniers
2020-04-14 20:53 ` Kees Cook
2020-04-15 10:32 ` Ard Biesheuvel
2020-04-15 12:58 ` Arnd Bergmann
2020-04-15 14:44 ` Russell King - ARM Linux admin
2020-04-19 11:08 ` Stefan Agner
2020-04-15 15:44 ` Kees Cook
2020-04-17 14:12 ` Masahiro Yamada
2020-04-13 19:23 ` Nick Desaulniers
2020-04-13 21:00 ` Russell King - ARM Linux admin
2020-11-04 20:44 ` Nick Desaulniers
2020-04-13 19:20 ` Nick Desaulniers
2020-04-13 21:15 ` Andrew Lunn
2020-04-10 16:59 ` Andrew Lunn
2020-04-10 18:34 ` Russell King - ARM Linux admin
2020-04-13 19:26 ` Nick Desaulniers
2020-04-13 21:53 ` Russell King - ARM Linux admin
2020-11-07 0:10 ` [PATCH v2] Make iwmmxt.S support Clang's integrated assembler Jian Cai
2020-11-07 8:29 ` Ard Biesheuvel
2020-11-10 1:55 ` Nick Desaulniers
2020-11-10 7:35 ` Ard Biesheuvel
2020-11-10 19:26 ` Nick Desaulniers
[not found] ` <CA+SOCLJSSR62VfWhKx9R1cxT-CHXD7RN08eJBYxUH8zzyWos9Q@mail.gmail.com>
2020-11-10 20:11 ` Nick Desaulniers
2020-11-10 20:38 ` Arnd Bergmann
2020-11-10 21:35 ` Ard Biesheuvel
2020-11-12 8:42 ` Ard Biesheuvel
2020-11-12 13:06 ` Arnd Bergmann
2020-11-12 20:07 ` [PATCH v3] " Jian Cai
2020-11-17 0:37 ` [PATCH v4] " Jian Cai
2020-11-17 1:20 ` Nick Desaulniers
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