From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnd Bergmann <arnd@arndb.de>
Subject: Re: next build: 235 warnings 3 failures (next/next-20151117)
Date: Tue, 17 Nov 2015 18:03:40 +0100
Message-ID: <6370082.rfihnaNWhf@wuerfel>
References: <564a9961.878b420a.331b8.fffffd62@mx.google.com> <4694362.ZPL12j6kR2@wuerfel> <20151117164453.GF30101@arm.com>
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Cc: Catalin Marinas <catalin.marinas@arm.com>,
	kernel-build-reports@lists.linaro.org, olof@lixom.net,
	David Miller <davem@davemloft.net>, eric.dumazet@gmail.com,
	netdev@vger.kernel.org, linux-next@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
To: Will Deacon <will.deacon@arm.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20151117164453.GF30101@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

On Tuesday 17 November 2015 16:44:53 Will Deacon wrote:
> > 8<----
> > Subject: ARM64: make smp_load_acquire() work with const arguments
> > 
> > smp_load_acquire() uses typeof() to declare a local variable for temporarily
> > storing the output of the memory access. This fails when the argument is
> > constant, because the assembler complains about using a constant register
> > as output:
> > 
> >  arch/arm64/include/asm/barrier.h:71:3: error: read-only variable '___p1'
> >  used as 'asm' output
> 
> Do you know the usage in the kernel causing this warning?

A newly introduced function in include/net/sock.h:

static inline int sk_state_load(const struct sock *sk)
{
        return smp_load_acquire(&sk->sk_state);
}

	Arnd