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Date:   Fri, 27 Oct 2023 08:57:36 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Lu Baolu <baolu.lu@linux.intel.com>
Cc:     Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Kevin Tian <kevin.tian@intel.com>, iommu@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] iommu: Avoid unnecessary cache invalidations
Message-ID: <ZTtfYPenwmd6W3nX@8bytes.org>
References: <20231026084942.17387-1-baolu.lu@linux.intel.com>
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On Thu, Oct 26, 2023 at 04:49:42PM +0800, Lu Baolu wrote:
> The iommu_create_device_direct_mappings() only needs to flush the caches
> when the mappings are changed in the affected domain. This is not true
> for non-DMA domains, or for devices attached to the domain that have no
> reserved regions. To avoid unnecessary cache invalidations, add a check
> before iommu_flush_iotlb_all().
> 
> Fixes: a48ce36e2786 ("iommu: Prevent RESV_DIRECT devices from blocking domains")
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/iommu/iommu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied, thanks.