On Mon, Sep 28, 2020 at 09:52:12AM +0200, Thierry Reding wrote: > On Sat, Sep 26, 2020 at 01:07:17AM -0700, Nicolin Chen wrote: > > @@ -13,6 +13,7 @@ > > #include <linux/platform_device.h> > > #include <linux/slab.h> > > #include <linux/spinlock.h> > > +#include <linux/dma-iommu.h> > > Why is this needed? I don't see any of the symbols declared in that file > used here. Hmm..I think I mixed with some other change that needs this header file. Removing it.... > > #include <linux/dma-mapping.h> > > > > #include <soc/tegra/ahb.h> > > @@ -61,6 +62,8 @@ struct tegra_smmu_as { > > u32 attr; > > }; > > > > +static const struct iommu_ops tegra_smmu_ops; > > + > > static struct tegra_smmu_as *to_smmu_as(struct iommu_domain *dom) > > { > > return container_of(dom, struct tegra_smmu_as, domain); > > @@ -484,60 +487,49 @@ static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu, > > static int tegra_smmu_attach_dev(struct iommu_domain *domain, > > struct device *dev) > > { > > + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); > > struct tegra_smmu *smmu = dev_iommu_priv_get(dev); > > struct tegra_smmu_as *as = to_smmu_as(domain); > > - struct device_node *np = dev->of_node; > > - struct of_phandle_args args; > > - unsigned int index = 0; > > - int err = 0; > > - > > - while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index, > > - &args)) { > > - unsigned int swgroup = args.args[0]; > > - > > - if (args.np != smmu->dev->of_node) { > > - of_node_put(args.np); > > - continue; > > - } > > + int index, err = 0; > > > > - of_node_put(args.np); > > + if (!fwspec || fwspec->ops != &tegra_smmu_ops) > > + return -ENOENT; > > > > + for (index = 0; index < fwspec->num_ids; index++) { > > err = tegra_smmu_as_prepare(smmu, as); > > - if (err < 0) > > - return err; > > + if (err) > > + goto err_disable; > > I'd personally drop the err_ prefix here because it's pretty obvious > that we're going to do this as a result of an error happening. Changing to "goto disable". > > @@ -845,10 +837,25 @@ static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev, > > return 0; > > } > > > > +static struct tegra_smmu *tegra_smmu_get_by_fwnode(struct fwnode_handle *fwnode) > > +{ > > + struct device *dev = driver_find_device_by_fwnode(&tegra_mc_driver.driver, fwnode); > > + struct tegra_mc *mc; > > + > > + if (!dev) > > + return NULL; > > + > > + put_device(dev); > > + mc = dev_get_drvdata(dev); > > + > > + return mc->smmu; > > +} > > + > > As I mentioned in another reply, I think tegra_smmu_find() should be all > you need in this case. This function is used by .probe_device() where its dev pointer is an SMMU client. IIUC, tegra_smmu_find() needs np pointer of "mc". For a PCI device that doesn't have a DT node with iommus property, not sure how we can use tegra_smmu_find().