Messages in this thread |  | | Date | Wed, 3 Dec 2025 15:34:26 +0000 | | Subject | Re: [PATCH V3 1/3] iommu/arm-smmu-v3: Add device-tree support for CMDQV driver | | From | Jon Hunter <> |
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On 01/12/2025 16:32, Ashish Mhetre wrote: > Add device tree support to the CMDQV driver to enable usage on Tegra264 > SoCs. The implementation parses the nvidia,cmdqv phandle from the SMMU > device tree node to associate each SMMU with its corresponding CMDQV > instance based on compatible string. > > Remove the dependency from Kconfig as the driver now supports both ACPI > and device tree initialization through conditional compilation and > ARM_SMMU_V3 depends on ARM64 which implies at least OF. > > Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> > Signed-off-by: Ashish Mhetre <amhetre@nvidia.com> > --- > drivers/iommu/arm/Kconfig | 1 - > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 32 ++++++++++++++ > .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 43 ++++++++++++++++++- > 3 files changed, 74 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/arm/Kconfig b/drivers/iommu/arm/Kconfig > index ef42bbe07dbe..5fac08b89dee 100644 > --- a/drivers/iommu/arm/Kconfig > +++ b/drivers/iommu/arm/Kconfig > @@ -121,7 +121,6 @@ config ARM_SMMU_V3_KUNIT_TEST > > config TEGRA241_CMDQV > bool "NVIDIA Tegra241 CMDQ-V extension support for ARM SMMUv3" > - depends on ACPI > help > Support for NVIDIA CMDQ-Virtualization extension for ARM SMMUv3. The > CMDQ-V extension is similar to v3.3 ECMDQ for multi command queues > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > index a33fbd12a0dd..206dffabc9c0 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -4530,6 +4530,35 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) > return 0; > } > > +#ifdef CONFIG_TEGRA241_CMDQV > +static void tegra_cmdqv_dt_probe(struct device_node *smmu_node, > + struct arm_smmu_device *smmu) > +{ > + struct platform_device *pdev; > + struct device_node *np; > + > + np = of_parse_phandle(smmu_node, "nvidia,cmdqv", 0); > + if (!np) > + return; > + > + pdev = of_find_device_by_node(np); > + of_node_put(np); > + if (!pdev) > + return; > + > + smmu->impl_dev = &pdev->dev; > + smmu->options |= ARM_SMMU_OPT_TEGRA241_CMDQV; > + dev_info(smmu->dev, "found companion CMDQV device: %s\n", > + dev_name(smmu->impl_dev)); > + put_device(&pdev->dev); > +} > +#else > +static void tegra_cmdqv_dt_probe(struct device_node *smmu_node, > + struct arm_smmu_device *smmu) > +{ > +} > +#endif > + > #ifdef CONFIG_ACPI > #ifdef CONFIG_TEGRA241_CMDQV > static void acpi_smmu_dsdt_probe_tegra241_cmdqv(struct acpi_iort_node *node, > @@ -4634,6 +4663,9 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev, > if (of_dma_is_coherent(dev->of_node)) > smmu->features |= ARM_SMMU_FEAT_COHERENCY; > > + if (of_device_is_compatible(dev->of_node, "nvidia,tegra264-smmu")) > + tegra_cmdqv_dt_probe(dev->of_node, smmu); > + > return ret; > } > > diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c > index 378104cd395e..2608bf6518b4 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c > +++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c > @@ -11,6 +11,8 @@ > #include <linux/iommufd.h> > #include <linux/iopoll.h> > #include <uapi/linux/iommufd.h> > +#include <linux/of_platform.h> > +#include <linux/platform_device.h> > > #include <acpi/acpixf.h> > > @@ -917,6 +919,26 @@ tegra241_cmdqv_find_acpi_resource(struct device *dev, int *irq) > return res; > } > > +static struct resource * > +tegra241_cmdqv_find_dt_resource(struct device *dev, int *irq) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct resource *res; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) { > + dev_err(dev, "no memory resource found for CMDQV\n"); > + return NULL; > + } > + > + if (irq) > + *irq = platform_get_irq_optional(pdev, 0); > + if (!irq || *irq <= 0) > + dev_warn(dev, "no interrupt. errors will not be reported\n"); > + > + return res; > +} > + > static int tegra241_cmdqv_init_structures(struct arm_smmu_device *smmu) > { > struct tegra241_cmdqv *cmdqv = > @@ -1048,11 +1070,14 @@ struct arm_smmu_device *tegra241_cmdqv_probe(struct arm_smmu_device *smmu) > > if (!smmu->dev->of_node) > res = tegra241_cmdqv_find_acpi_resource(smmu->impl_dev, &irq); > + else > + res = tegra241_cmdqv_find_dt_resource(smmu->impl_dev, &irq); > if (!res) > goto out_fallback; > > new_smmu = __tegra241_cmdqv_probe(smmu, res, irq); > - kfree(res); > + if (!smmu->dev->of_node) > + kfree(res); > > if (new_smmu) > return new_smmu; > @@ -1346,4 +1371,20 @@ tegra241_cmdqv_init_vintf_user(struct arm_vsmmu *vsmmu, > return ret; > } > > +static const struct of_device_id tegra241_cmdqv_of_match[] = { > + { .compatible = "nvidia,tegra264-cmdqv" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, tegra241_cmdqv_of_match); > + > +static struct platform_driver tegra241_cmdqv_driver = { > + .driver = { > + .name = "tegra241-cmdqv", > + .of_match_table = tegra241_cmdqv_of_match, > + }, > +}; > +module_platform_driver(tegra241_cmdqv_driver);
This part looks a bit weird, because it appears to do nothing. The compatible string is not used at all in the driver AFAICT. Have you tried this bit out because this is not a proper driver?
Jon
-- nvpublic
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