Re: [PATCH 07/13] add domain_flush_cache

[Mark McLoughlin <markmc@redhat.com>]

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.