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Date:   Fri, 26 Aug 2022 11:55:23 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Lu Baolu <baolu.lu@linux.intel.com>
Cc:     Joerg Roedel <joro@8bytes.org>,
        Christoph Hellwig <hch@infradead.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Eric Auger <eric.auger@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>,
        Jacob jun Pan <jacob.jun.pan@intel.com>,
        Zhangfei Gao <zhangfei.gao@linaro.org>,
        Zhu Tony <tony.zhu@intel.com>, iommu@lists.linux.dev,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v12 08/17] iommu: Make free of iommu_domain_ops optional
Message-ID: <Ywje2199uFTzCubw@ziepe.ca>
References: <20220826121141.50743-1-baolu.lu@linux.intel.com>
 <20220826121141.50743-9-baolu.lu@linux.intel.com>
 <YwjeW+nSIDkmmggd@nvidia.com>
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On Fri, Aug 26, 2022 at 11:53:15AM -0300, Jason Gunthorpe wrote:
> On Fri, Aug 26, 2022 at 08:11:32PM +0800, Lu Baolu wrote:
> > So that the drivers are able to implement static singleton instance for
> > some special domains. The blocking domain is an example. The driver has
> > no need to allocate different memory for each blocking domain allocation
> > request. Hence, no need for a free callback.
> > 
> > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> > Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> > Tested-by: Tony Zhu <tony.zhu@intel.com>
> > ---
> >  drivers/iommu/iommu.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > index e985f4d5895f..630e1b64ed89 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -1972,7 +1972,8 @@ void iommu_domain_free(struct iommu_domain *domain)
> >  	if (domain->type == IOMMU_DOMAIN_SVA)
> >  		mmdrop(domain->mm);
> >  	iommu_put_dma_cookie(domain);
> > -	domain->ops->free(domain);
> > +	if (domain->ops->free)
> > +		domain->ops->free(domain);
> >  }
> >  EXPORT_SYMBOL_GPL(iommu_domain_free);
> 
> This patch is in the wrong order, it needs to be before the ARM patch
> implementing the blocking domain

Oh, nevermind, I am reading them in the wrong order :)

Jason