Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 28 Sep 2020 09:55:45 +0200
From:   Thierry Reding <thierry.reding@gmail.com>
To:     Nicolin Chen <nicoleotsuka@gmail.com>
Cc:     joro@8bytes.org, krzk@kernel.org, vdumpa@nvidia.com,
        jonathanh@nvidia.com, linux-tegra@vger.kernel.org,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/5] iommu/tegra-smmu: Add PCI support
Message-ID: <20200928075545.GG2837573@ulmo>
References: <20200926080719.6822-1-nicoleotsuka@gmail.com>
 <20200926080719.6822-5-nicoleotsuka@gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;
        protocol="application/pgp-signature"; boundary="QWpDgw58+k1mSFBj"
Content-Disposition: inline
In-Reply-To: <20200926080719.6822-5-nicoleotsuka@gmail.com>
User-Agent: Mutt/1.14.7 (2020-08-29)
Precedence: bulk


--QWpDgw58+k1mSFBj
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Sat, Sep 26, 2020 at 01:07:18AM -0700, Nicolin Chen wrote:
> This patch simply adds support for PCI devices.
>=20
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
> ---
>  drivers/iommu/tegra-smmu.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
>=20
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index 97a7185b4578..9dbc5d7183cc 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -15,6 +15,7 @@
>  #include <linux/spinlock.h>
>  #include <linux/dma-iommu.h>
>  #include <linux/dma-mapping.h>
> +#include <linux/pci.h>
> =20
>  #include <soc/tegra/ahb.h>
>  #include <soc/tegra/mc.h>
> @@ -935,6 +936,7 @@ static struct iommu_group *tegra_smmu_device_group(st=
ruct device *dev)
>  	const struct tegra_smmu_group_soc *soc;
>  	struct tegra_smmu_group *group;
>  	int swgroup =3D fwspec->ids[0];
> +	bool pci =3D dev_is_pci(dev);
>  	struct iommu_group *grp;
> =20
>  	/* Find group_soc associating with swgroup */
> @@ -961,7 +963,7 @@ static struct iommu_group *tegra_smmu_device_group(st=
ruct device *dev)
>  	group->smmu =3D smmu;
>  	group->soc =3D soc;
> =20
> -	group->group =3D iommu_group_alloc();
> +	group->group =3D pci ? pci_device_group(dev) : iommu_group_alloc();
>  	if (IS_ERR(group->group)) {
>  		devm_kfree(smmu->dev, group);
>  		mutex_unlock(&smmu->lock);
> @@ -1180,6 +1182,19 @@ struct tegra_smmu *tegra_smmu_probe(struct device =
*dev,
>  		return ERR_PTR(err);
>  	}
> =20
> +#ifdef CONFIG_PCI
> +	if (!iommu_present(&pci_bus_type)) {
> +		pci_request_acs();
> +		err =3D bus_set_iommu(&pci_bus_type, &tegra_smmu_ops);
> +		if (err < 0) {
> +			bus_set_iommu(&platform_bus_type, NULL);
> +			iommu_device_unregister(&smmu->iommu);
> +			iommu_device_sysfs_remove(&smmu->iommu);
> +			return ERR_PTR(err);

It might be worth factoring out the cleanup code now that there are
multiple failures from which we may need to clean up.

Also, it'd be great if somehow we could do this without the #ifdef,
but I guess since we're using the pci_bus_type global variable directly,
there isn't much we can do here?

Thierry

--QWpDgw58+k1mSFBj
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=8eZB
-----END PGP SIGNATURE-----

--QWpDgw58+k1mSFBj--