Date: Thu, 8 Dec 2016 13:27:46 +0000
From: Catalin Marinas <catalin.marinas@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Christopher Covington <cov@codeaurora.org>, kvm@vger.kernel.org,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Marc Zyngier <marc.zyngier@arm.com>, Will Deacon <will.deacon@arm.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Paolo Bonzini <pbonzini@redhat.com>, kvmarm@lists.cs.columbia.edu,
        Christoffer Dall <christoffer.dall@linaro.org>
Subject: Re: [PATCH] arm64: Work around Falkor erratum 1009
Message-ID: <20161208132746.GB15141@e104818-lin.cambridge.arm.com>
References: <20161207200028.4420-1-cov@codeaurora.org>
 <20161207200431.4587-1-cov@codeaurora.org>
 <20161208114511.GC9768@leverpostej>
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On Thu, Dec 08, 2016 at 11:45:12AM +0000, Mark Rutland wrote:
> On Wed, Dec 07, 2016 at 03:04:31PM -0500, Christopher Covington wrote:
> > +	asm volatile(ALTERNATIVE(
> > +		     "nop \n"
> > +		     "nop \n",
> > +		     "tlbi vmalle1is \n"
> > +		     "dsb ish \n",
> 
> As a general note, perhaps we want a C compatible NOP_ALTERNATIVE() so
> that the nop case can be implicitly generated for sequences like this.

It's also worth checking what cpus_have_const_cap() would generate for
the default (no workaround required) case.

-- 
Catalin