From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH v6 13/21] iommu/tegra: gart: Integrate with Memory Controller driver Date: Wed, 12 Dec 2018 11:14:07 +0100 Message-ID: <20181212101407.GJ15092@ulmo> References: <20181209202950.31486-1-digetx@gmail.com> <20181209202950.31486-14-digetx@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Do4IU1xF/9sod/r6" Return-path: Content-Disposition: inline In-Reply-To: <20181209202950.31486-14-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko Cc: Jonathan Hunter , Joerg Roedel , Robin Murphy , iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org --Do4IU1xF/9sod/r6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Dec 09, 2018 at 11:29:42PM +0300, Dmitry Osipenko wrote: > The device-tree binding has been changed. There is no separate GART device > anymore, it is squashed into the Memory Controller. Integrate GART module > with the MC in a way it is done for the SMMU of Tegra30+. >=20 > Signed-off-by: Dmitry Osipenko > --- > drivers/iommu/Kconfig | 1 + > drivers/iommu/tegra-gart.c | 77 ++++++++++++-------------------------- > drivers/memory/tegra/mc.c | 41 ++++++++++++++++++++ > include/soc/tegra/mc.h | 27 +++++++++++++ > 4 files changed, 93 insertions(+), 53 deletions(-) >=20 > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > index d9a25715650e..83c099bb7288 100644 > --- a/drivers/iommu/Kconfig > +++ b/drivers/iommu/Kconfig > @@ -282,6 +282,7 @@ config ROCKCHIP_IOMMU > config TEGRA_IOMMU_GART > bool "Tegra GART IOMMU Support" > depends on ARCH_TEGRA_2x_SOC > + depends on TEGRA_MC > select IOMMU_API > help > Enables support for remapping discontiguous physical memory > diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c > index 835fea461c59..0a72b6afa842 100644 > --- a/drivers/iommu/tegra-gart.c > +++ b/drivers/iommu/tegra-gart.c > @@ -19,16 +19,17 @@ > * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. > */ > =20 > -#include > #include > #include > #include > #include > -#include > +#include > #include > #include > #include > =20 > +#include > + > /* bitmap of the page sizes currently supported */ > #define GART_IOMMU_PGSIZES (SZ_4K) > =20 > @@ -397,9 +398,8 @@ static const struct iommu_ops gart_iommu_ops =3D { > .iotlb_sync =3D gart_iommu_sync, > }; > =20 > -static int tegra_gart_suspend(struct device *dev) > +int tegra_gart_suspend(struct gart_device *gart) > { > - struct gart_device *gart =3D dev_get_drvdata(dev); > unsigned long iova; > u32 *data =3D gart->savedata; > unsigned long flags; > @@ -411,9 +411,8 @@ static int tegra_gart_suspend(struct device *dev) > return 0; > } > =20 > -static int tegra_gart_resume(struct device *dev) > +int tegra_gart_resume(struct gart_device *gart) > { > - struct gart_device *gart =3D dev_get_drvdata(dev); > unsigned long flags; > =20 > spin_lock_irqsave(&gart->pte_lock, flags); > @@ -422,41 +421,39 @@ static int tegra_gart_resume(struct device *dev) > return 0; > } > =20 > -static int tegra_gart_probe(struct platform_device *pdev) > +struct gart_device *tegra_gart_probe(struct device *dev, > + const struct tegra_smmu_soc *soc, > + struct tegra_mc *mc) > { > struct gart_device *gart; > - struct resource *res, *res_remap; > + struct resource *res_remap; > void __iomem *gart_regs; > - struct device *dev =3D &pdev->dev; > int ret; > =20 > BUILD_BUG_ON(PAGE_SHIFT !=3D GART_PAGE_SHIFT); > =20 > + /* Tegra30+ has an SMMU and no GART */ > + if (soc) > + return NULL; This looks weird. Why do we even call tegra_gart_probe() on anything but Tegra20? > + > /* the GART memory aperture is required */ > - res =3D platform_get_resource(pdev, IORESOURCE_MEM, 0); > - res_remap =3D platform_get_resource(pdev, IORESOURCE_MEM, 1); > - if (!res || !res_remap) { > + res_remap =3D platform_get_resource(to_platform_device(dev), > + IORESOURCE_MEM, 1); > + if (!res_remap) { > dev_err(dev, "GART memory aperture expected\n"); > - return -ENXIO; > + return ERR_PTR(-ENXIO); > } > =20 > gart =3D devm_kzalloc(dev, sizeof(*gart), GFP_KERNEL); > if (!gart) { > dev_err(dev, "failed to allocate gart_device\n"); > - return -ENOMEM; > + return ERR_PTR(-ENOMEM); > } > =20 > - gart_regs =3D devm_ioremap(dev, res->start, resource_size(res)); > - if (!gart_regs) { > - dev_err(dev, "failed to remap GART registers\n"); > - return -ENXIO; > - } > - > - ret =3D iommu_device_sysfs_add(&gart->iommu, &pdev->dev, NULL, > - dev_name(&pdev->dev)); > + ret =3D iommu_device_sysfs_add(&gart->iommu, dev, NULL, "gart"); > if (ret) { > dev_err(dev, "Failed to register IOMMU in sysfs\n"); > - return ret; > + return ERR_PTR(ret); > } > =20 > iommu_device_set_ops(&gart->iommu, &gart_iommu_ops); > @@ -468,7 +465,8 @@ static int tegra_gart_probe(struct platform_device *p= dev) > goto remove_sysfs; > } > =20 > - gart->dev =3D &pdev->dev; > + gart->dev =3D dev; > + gart_regs =3D mc->regs + GART_REG_BASE; > spin_lock_init(&gart->pte_lock); > spin_lock_init(&gart->client_lock); > INIT_LIST_HEAD(&gart->client); > @@ -483,46 +481,19 @@ static int tegra_gart_probe(struct platform_device = *pdev) > goto unregister_iommu; > } > =20 > - platform_set_drvdata(pdev, gart); > do_gart_setup(gart, NULL); > =20 > gart_handle =3D gart; > =20 > - return 0; > + return gart; > =20 > unregister_iommu: > iommu_device_unregister(&gart->iommu); > remove_sysfs: > iommu_device_sysfs_remove(&gart->iommu); > =20 > - return ret; > -} > - > -static const struct dev_pm_ops tegra_gart_pm_ops =3D { > - .suspend =3D tegra_gart_suspend, > - .resume =3D tegra_gart_resume, > -}; > - > -static const struct of_device_id tegra_gart_of_match[] =3D { > - { .compatible =3D "nvidia,tegra20-gart", }, > - { }, > -}; > - > -static struct platform_driver tegra_gart_driver =3D { > - .probe =3D tegra_gart_probe, > - .driver =3D { > - .name =3D "tegra-gart", > - .pm =3D &tegra_gart_pm_ops, > - .of_match_table =3D tegra_gart_of_match, > - .suppress_bind_attrs =3D true, > - }, > -}; > - > -static int __init tegra_gart_init(void) > -{ > - return platform_driver_register(&tegra_gart_driver); > + return ERR_PTR(ret); > } > -subsys_initcall(tegra_gart_init); > =20 > module_param(gart_debug, bool, 0644); > MODULE_PARM_DESC(gart_debug, "Enable GART debugging"); > diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c > index 55ecfb2d8cfd..4cae1c3a853b 100644 > --- a/drivers/memory/tegra/mc.c > +++ b/drivers/memory/tegra/mc.c > @@ -702,13 +702,54 @@ static int tegra_mc_probe(struct platform_device *p= dev) > PTR_ERR(mc->smmu)); > } > =20 > + if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART)) { > + mc->gart =3D tegra_gart_probe(&pdev->dev, mc->soc->smmu, mc); > + if (IS_ERR(mc->gart)) > + dev_err(&pdev->dev, "failed to probe GART: %ld\n", > + PTR_ERR(mc->gart)); > + } Perhaps if we add a check for for !mc->soc->smmu here we can avoid passing this data structure to tegra_gart_probe() and remove the corresponding check from tegra_gart_probe(). That seems more like a more logical sequence than attempting to probe GART on device that may not have one and return. Also, since there's no error return here, do we want to set mc->gart to NULL on error to avoid crashing later on... > + > + return 0; > +} > + > +static int tegra_mc_suspend(struct device *dev) > +{ > + struct tegra_mc *mc =3D dev_get_drvdata(dev); > + int err; > + > + if (mc->gart) { =2E.. like here? > + err =3D tegra_gart_suspend(mc->gart); > + if (err) > + return err; > + } > + > return 0; > } > =20 > +static int tegra_mc_resume(struct device *dev) > +{ > + struct tegra_mc *mc =3D dev_get_drvdata(dev); > + int err; > + > + if (mc->gart) { And here? > + err =3D tegra_gart_resume(mc->gart); > + if (err) > + return err; > + } > + > + return 0; > +} > + > +static const struct dev_pm_ops tegra_mc_pm_ops =3D { > + .suspend =3D tegra_mc_suspend, > + .resume =3D tegra_mc_resume, > +}; > + > static struct platform_driver tegra_mc_driver =3D { > .driver =3D { > .name =3D "tegra-mc", > .of_match_table =3D tegra_mc_of_match, > + .pm =3D &tegra_mc_pm_ops, > .suppress_bind_attrs =3D true, > }, > .prevent_deferred_probe =3D true, > diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h > index db5bfdf589b4..5da42e3fb801 100644 > --- a/include/soc/tegra/mc.h > +++ b/include/soc/tegra/mc.h > @@ -77,6 +77,7 @@ struct tegra_smmu_soc { > =20 > struct tegra_mc; > struct tegra_smmu; > +struct gart_device; > =20 > #ifdef CONFIG_TEGRA_IOMMU_SMMU > struct tegra_smmu *tegra_smmu_probe(struct device *dev, > @@ -96,6 +97,31 @@ static inline void tegra_smmu_remove(struct tegra_smmu= *smmu) > } > #endif > =20 > +#ifdef CONFIG_TEGRA_IOMMU_GART > +struct gart_device *tegra_gart_probe(struct device *dev, > + const struct tegra_smmu_soc *soc, > + struct tegra_mc *mc); > +int tegra_gart_suspend(struct gart_device *gart); > +int tegra_gart_resume(struct gart_device *gart); > +#else > +static inline struct gart_device * > +tegra_gart_probe(struct device *dev, const struct tegra_smmu_soc *soc, > + struct tegra_mc *mc) > +{ > + return NULL; > +} > + > +static inline int tegra_gart_suspend(struct gart_device *gart) > +{ > + return -ENODEV; > +} > + > +static inline int tegra_gart_resume(struct gart_device *gart) > +{ > + return -ENODEV; > +} > +#endif That doesn't look right. If we don't enable GART, then the dummy implementations will be used, but they return error codes, so suspend/resume of MC will also fail, causing the whole system to not be able to suspend if GART is disabled. I think it'd be better to avoid the dummy functions and instead add extra checks for IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) where these are called. That way references to these functions should be discarded at translation time. To be specific, tegra_mc_suspend() and tegra_mc_resume() would change like this: if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && mc->gart) Thierry --Do4IU1xF/9sod/r6 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAlwQ324ACgkQ3SOs138+ s6Fk7xAAsQkWgAOy3a1e8km4a/1eMiv+ODQ/SxbNo9Owwn4+IXOYQVrSP85ooA/Z fHAuNcOKgCGw/buzgv2CXzMBmQyHDr92OS1PSHWMpC0qtTOqlXTZIWiyizvk1lQ1 glkqDjBj3uInQWunUadUhyD3gsyjSNxDXbCrJ0YlOjrGKtekWGqqtVyLK7Rb9/qg zvQNgTJf+tvy562WbWz3+OC6rxhE0iwnpwPibT89LpG6tYy9zEB4LIxieD1uhH6R r+iN4ghp/uFq1a2kK8x46C/OBFnuy+TwvTMC0R4Rf56tKkAG1FyG72o3Q2UGQb6P 1NH3j+xvFyax0j834pYUp5GGy/T0w0M7dA3AYFWoMIQgpmUQxqRn8Lm1k7JZ6lHP mJFCMhwdm33vb04W/XC+nRu6l3HHvcQscCqxS7VIw4Cj+3FpTPrY1jSAgsyE0MRw dELYf9wVxj6ZfozyZAXRbwJit4S93ckrXRpMtDv9/n3ULZ66WO7IVuylWrd86rlx FmsFoQ/1CL/HrrnzSED/dh5kNC5H1Upn6n+R6tZua70oHAhlh3LuD5gUyAK8aWB9 KMd5ZJ94t/fIn/FPPIyxgmZUGp6xL1ljvXQ47TFbfqiYAhnqd+NPDk2CJ2wwaEjj UQaZiHNJt8JzZMLbwLCq3MySIRtaArTn7B9yZFrW8UyH+mzS3jI= =aFQ1 -----END PGP SIGNATURE----- --Do4IU1xF/9sod/r6--