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From:   "Tian, Kevin" <kevin.tian@intel.com>
To:     Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>,
        "Will Deacon" <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        "Jason Gunthorpe" <jgg@ziepe.ca>,
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CC:     "Liu, Yi L" <yi.l.liu@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
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        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
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Subject: RE: [PATCH v2 05/12] iommu: Change the return value of
 dev_iommu_get()
Thread-Topic: [PATCH v2 05/12] iommu: Change the return value of
 dev_iommu_get()
Thread-Index: AQHZwE5aOEc+6ikxPE+EMdq5oUz2zq/YPxrQ
Date:   Thu, 3 Aug 2023 07:59:56 +0000
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 <20230727054837.147050-6-baolu.lu@linux.intel.com>
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> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Thursday, July 27, 2023 1:49 PM
>=20
> Make dev_iommu_get() return 0 for success and error numbers for failure.
> This will make the code neat and readable. No functionality changes.
>=20
> Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/iommu/iommu.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
>=20
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 00309f66153b..4ba3bb692993 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -290,20 +290,20 @@ void iommu_device_unregister(struct
> iommu_device *iommu)
>  }
>  EXPORT_SYMBOL_GPL(iommu_device_unregister);
>=20
> -static struct dev_iommu *dev_iommu_get(struct device *dev)
> +static int dev_iommu_get(struct device *dev)
>  {
>  	struct dev_iommu *param =3D dev->iommu;
>=20
>  	if (param)
> -		return param;
> +		return 0;
>=20
>  	param =3D kzalloc(sizeof(*param), GFP_KERNEL);
>  	if (!param)
> -		return NULL;
> +		return -ENOMEM;
>=20
>  	mutex_init(&param->lock);
>  	dev->iommu =3D param;
> -	return param;
> +	return 0;
>  }
>=20

Jason's series [1] has been queued. Time to refine according to
the discussion in [2].

[1] https://lore.kernel.org/linux-iommu/ZLFYXlSBZrlxFpHM@8bytes.org/
[2] https://lore.kernel.org/linux-iommu/c815fa2b-00df-91e1-8353-8258773957e=
4@linux.intel.com/