From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark McLoughlin <markmc@redhat.com>
Subject: Re: [PATCH 07/13] add domain_flush_cache
Date: Thu, 04 Dec 2008 17:12:57 +0000
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Cc: "'Avi Kivity'" <avi@redhat.com>,
	"Woodhouse, David" <david.woodhouse@intel.com>,
	"'Jesse Barnes'" <jbarnes@virtuousgeek.org>,
	"Yu, Fenghua" <fenghua.yu@intel.com>,
	"'iommu@lists.linux-foundation.org'"
	<iommu@lists.linux-foundation.org>,
	"'kvm@vger.kernel.org'" <kvm@vger.kernel.org>
To: "Han, Weidong" <weidong.han@intel.com>
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On Tue, 2008-12-02 at 22:22 +0800, Han, Weidong wrote:

> For some common low level functions which will be also used by virtual
> machine usage, use domain_flush_cache instead of __iommu_flush_cache.
> 
> Signed-off-by: Weidong Han <weidong.han@intel.com>
> ---
>  drivers/pci/intel-iommu.c |   40 ++++++++++++++++++++++++----------------
>  1 files changed, 24 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
> index 429aff4..b00a8f2 100644
> --- a/drivers/pci/intel-iommu.c
> +++ b/drivers/pci/intel-iommu.c
> @@ -200,6 +200,13 @@ static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
>  	return NULL;
>  }
>  
> +static void domain_flush_cache(struct dmar_domain *domain,
> +			       void *addr, int size)
> +{
> +	if (!domain->iommu_coherency)
> +		clflush_cache_range(addr, size);
> +}

This is quite unfortunate; __iommu_flush_cache() is essentially
identical:

static inline void __iommu_flush_cache(
        struct intel_iommu *iommu, void *addr, int size)
{
        if (!ecap_coherent(iommu->ecap))
                clflush_cache_range(addr, size);
}

Is there no way we can use a single function for both purposes?

Cheers,
Mark.