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Date:   Sun, 14 Apr 2019 23:33:51 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Tom Murphy <tmurphy@arista.com>
Cc:     iommu@lists.linux-foundation.org, Heiko Stuebner <heiko@sntech.de>,
        Will Deacon <will.deacon@arm.com>,
        David Brown <david.brown@linaro.org>,
        linux-samsung-soc@vger.kernel.org, dima@arista.com,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-rockchip@lists.infradead.org, Kukjin Kim <kgene@kernel.org>,
        Andy Gross <andy.gross@linaro.org>,
        Marc Zyngier <marc.zyngier@arm.com>,
        linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        murphyt7@tcd.ie, Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH 5/9] iommu/amd: Implement .flush_np_cache
Message-ID: <20190415063351.GD1377@infradead.org>
References: <20190411184741.27540-1-tmurphy@arista.com>
 <20190411184741.27540-6-tmurphy@arista.com>
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> +static void amd_iommu_flush_np_cache(struct iommu_domain *domain,
> +		unsigned long iova, size_t size)
> +{
> +	struct protection_domain *dom = to_pdomain(domain);
> +
> +	if (unlikely(amd_iommu_np_cache)) {

Is this case really so unlikely that it needs a static branch prediction
hint?