Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Stefan Agner <stefan@agner.ch>
To: linux@armlinux.org.uk
Cc: nicolas.pitre@linaro.org, mark.rutland@arm.com, arnd@arndb.de,
	ard.biesheuvel@linaro.org, will.deacon@arm.com,
	julien.thierry@arm.com, ndesaulniers@google.com,
	linux-kernel@vger.kernel.org, thierry.reding@gmail.com,
	natechancellor@gmail.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/5] ARM: use unified assembler in c files
Date: Sat, 09 Feb 2019 18:28:25 +0100
Message-ID: <db0e6b8f034f832c7e52fe3dd47073ad@agner.ch> (raw)
In-Reply-To: <fed4850fb5d8a8ca874affa05d8d116d53e25b88.1549532513.git.stefan@agner.ch>

Thanks for the reviews so far.

During some more testing I stumbled upon another issue:

On 07.02.2019 10:48, Stefan Agner wrote:
> Use unified assembler syntax (UAL) in inline assembler. Divided
> syntax is considered depricated. This will also allow to build
> the kernel using LLVM's integrated assembler.
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
>  arch/arm/mm/copypage-v4mc.c | 2 +-
>  arch/arm/mm/copypage-v4wb.c | 2 +-
>  arch/arm/mm/copypage-v4wt.c | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c
> index b03202cddddb..b19c7ad1a6de 100644
> --- a/arch/arm/mm/copypage-v4mc.c
> +++ b/arch/arm/mm/copypage-v4mc.c
> @@ -56,7 +56,7 @@ static void mc_copy_user_page(void *from, void *to)
>  	ldmia	%0!, {r2, r3, ip, lr}		@ 4\n\
>  	subs	%2, %2, #1			@ 1\n\
>  	stmia	%1!, {r2, r3, ip, lr}		@ 4\n\
> -	ldmneia	%0!, {r2, r3, ip, lr}		@ 4\n\
> +	ldmiane	%0!, {r2, r3, ip, lr}		@ 4\n\
>  	bne	1b				@ "
>  	: "+&r" (from), "+&r" (to), "=&r" (tmp)
>  	: "2" (PAGE_SIZE / 64)
> diff --git a/arch/arm/mm/copypage-v4wb.c b/arch/arm/mm/copypage-v4wb.c
> index cd3e165afeed..6e3c9b69dd25 100644
> --- a/arch/arm/mm/copypage-v4wb.c
> +++ b/arch/arm/mm/copypage-v4wb.c
> @@ -38,7 +38,7 @@ static void v4wb_copy_user_page(void *kto, const void *kfrom)
>  	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
>  	subs	%2, %2, #1			@ 1\n\
>  	stmia	%0!, {r3, r4, ip, lr}		@ 4\n\
> -	ldmneia	%1!, {r3, r4, ip, lr}		@ 4\n\
> +	ldmiane	%1!, {r3, r4, ip, lr}		@ 4\n\
>  	bne	1b				@ 1\n\
>  	mcr	p15, 0, %1, c7, c10, 4		@ 1   drain WB"
>  	: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
> diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c
> index 8614572e1296..4a40fa1cbc2a 100644
> --- a/arch/arm/mm/copypage-v4wt.c
> +++ b/arch/arm/mm/copypage-v4wt.c
> @@ -34,7 +34,7 @@ static void v4wt_copy_user_page(void *kto, const void *kfrom)
>  	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
>  	subs	%2, %2, #1			@ 1\n\
>  	stmia	%0!, {r3, r4, ip, lr}		@ 4\n\
> -	ldmneia	%1!, {r3, r4, ip, lr}		@ 4\n\
> +	ldmiane	%1!, {r3, r4, ip, lr}		@ 4\n\
>  	bne	1b				@ 1\n\
>  	mcr	p15, 0, %2, c7, c7, 0		@ flush ID cache"
>  	: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)

When compiling with gcc, this leads to:

/tmp/ccrvA1wy.s: Assembler messages:
/tmp/ccrvA1wy.s:180: Error: bad instruction `ldmiane r0!,{r3,r4,ip,lr}'
make[1]: *** [scripts/Makefile.build:277: arch/arm/mm/copypage-v4wb.o]
Error 1
make: *** [Makefile:1042: arch/arm/mm] Error 2

Unfortunately, the gcc option -masm-syntax-unified which allows unified
syntax in inline assembly is broken (see also
https://lkml.org/lkml/2019/1/7/1320).

So this requires to sprinkle those inline assembly with ".syntax
unified" strings, similar to how I've done it in uaccess.h.

--
Stefan

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-07  9:48 [PATCH 0/5] ARM: convert to unified syntax Stefan Agner
2019-02-07  9:48 ` [PATCH 1/5] ARM: use unified assembler in macros Stefan Agner
2019-02-07 13:34   ` Ard Biesheuvel
2019-02-07 15:52   ` Nicolas Pitre
2019-02-07  9:48 ` [PATCH 2/5] ARM: use unified assembler in headers Stefan Agner
2019-02-07 16:10   ` Nicolas Pitre
2019-02-09 22:54     ` Stefan Agner
2019-02-07  9:48 ` [PATCH 3/5] ARM: use unified assembler in assembly files Stefan Agner
2019-02-07  9:48 ` [PATCH 4/5] ARM: use unified assembler in c files Stefan Agner
2019-02-09 17:28   ` Stefan Agner [this message]
2019-02-11 18:17     ` Nick Desaulniers
2019-02-12 19:26       ` Stefan Agner
2019-02-07  9:48 ` [PATCH 5/5] ARM: warn if divided syntax assembler is used Stefan Agner
2019-02-07 20:52   ` Nick Desaulniers

Reply instructions:

You may reply publically 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=db0e6b8f034f832c7e52fe3dd47073ad@agner.ch \
    --to=stefan@agner.ch \
    --cc=ard.biesheuvel@linaro.org \
    --cc=arnd@arndb.de \
    --cc=julien.thierry@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=mark.rutland@arm.com \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    --cc=nicolas.pitre@linaro.org \
    --cc=thierry.reding@gmail.com \
    --cc=will.deacon@arm.com \
    /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

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org infradead-linux-arm-kernel@archiver.kernel.org
	public-inbox-index linux-arm-kernel


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox