Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190517065424.24453-1-yamada.masahiro@socionext.com>
In-Reply-To: <20190517065424.24453-1-yamada.masahiro@socionext.com>
From:   Justin Forbes <jmforbes@linuxtx.org>
Date:   Mon, 20 May 2019 15:52:49 -0500
Message-ID: <CAFxkdApsrU0tOmCnGDa6HRJ6R3T1gG7o-DN5pZXV0g4Oov6yrA@mail.gmail.com>
Subject: Re: [PATCH] s390: mark __cpacf_check_opcode() and cpacf_query_func()
 as __always_inline
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        linux-s390@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
        Laura Abbott <labbott@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, May 17, 2019 at 1:55 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> Commit e60fb8bf68d4 ("s390/cpacf: mark scpacf_query() as __always_inline")
> was not enough to make sure to meet the 'i' (immediate) constraint for the
> asm operands.
>
> With CONFIG_OPTIMIZE_INLINING enabled, Laura Abbott reported error
> with gcc 9.1.1:
>
>   In file included from arch/s390/crypto/prng.c:29:
>   ./arch/s390/include/asm/cpacf.h: In function 'cpacf_query_func':
>   ./arch/s390/include/asm/cpacf.h:170:2: warning: asm operand 3 probably doesn't match constraints
>     170 |  asm volatile(
>         |  ^~~
>   ./arch/s390/include/asm/cpacf.h:170:2: error: impossible constraint in 'asm'
>
> Add more __always_inline to force inlining.
>
> Fixes: 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING")
> Reported-by: Laura Abbott <labbott@redhat.com>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
Thanks for the fix, this does indeed fix the build issues for us.

Justin

Tested-by: Justin Forbes <jforbes@fedoraproject.org>

>  arch/s390/include/asm/cpacf.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/s390/include/asm/cpacf.h b/arch/s390/include/asm/cpacf.h
> index f316de40e51b..19459dfb4295 100644
> --- a/arch/s390/include/asm/cpacf.h
> +++ b/arch/s390/include/asm/cpacf.h
> @@ -177,7 +177,7 @@ static inline void __cpacf_query(unsigned int opcode, cpacf_mask_t *mask)
>                 : "cc");
>  }
>
> -static inline int __cpacf_check_opcode(unsigned int opcode)
> +static __always_inline int __cpacf_check_opcode(unsigned int opcode)
>  {
>         switch (opcode) {
>         case CPACF_KMAC:
> @@ -217,7 +217,7 @@ static inline int cpacf_test_func(cpacf_mask_t *mask, unsigned int func)
>         return (mask->bytes[func >> 3] & (0x80 >> (func & 7))) != 0;
>  }
>
> -static inline int cpacf_query_func(unsigned int opcode, unsigned int func)
> +static __always_inline int cpacf_query_func(unsigned int opcode, unsigned int func)
>  {
>         cpacf_mask_t mask;
>
> --
> 2.17.1
>