diff mbox series

[v6,11/25] iommu/tegra-smmu: Implement an IDENTITY domain

Message ID 11-v6-e8114faedade+425-iommu_all_defdom_jgg@nvidia.com (mailing list archive)
State Handled Elsewhere
Headers show
Series iommu: Make default_domain's mandatory | expand

Commit Message

Jason Gunthorpe Aug. 3, 2023, 12:07 a.m. UTC
What tegra-smmu does during tegra_smmu_set_platform_dma() is actually
putting the iommu into identity mode.

Move to the new core support for ARM_DMA_USE_IOMMU by defining
ops->identity_domain.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/tegra-smmu.c | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

Comments

Baolu Lu Aug. 14, 2023, 5:01 a.m. UTC | #1
On 2023/8/3 8:07, Jason Gunthorpe wrote:
> What tegra-smmu does during tegra_smmu_set_platform_dma() is actually
> putting the iommu into identity mode.
> 
> Move to the new core support for ARM_DMA_USE_IOMMU by defining
> ops->identity_domain.
> 
> Signed-off-by: Jason Gunthorpe<jgg@nvidia.com>
> ---
>   drivers/iommu/tegra-smmu.c | 37 ++++++++++++++++++++++++++++++++-----
>   1 file changed, 32 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index 1cbf063ccf147a..f63f1d4f0bd10f 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -511,23 +511,39 @@ static int tegra_smmu_attach_dev(struct iommu_domain *domain,
>   	return err;
>   }
>   
> -static void tegra_smmu_set_platform_dma(struct device *dev)
> +static int tegra_smmu_identity_attach(struct iommu_domain *identity_domain,
> +				      struct device *dev)
>   {
>   	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
>   	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> -	struct tegra_smmu_as *as = to_smmu_as(domain);
> -	struct tegra_smmu *smmu = as->smmu;
> +	struct tegra_smmu_as *as;
> +	struct tegra_smmu *smmu;
>   	unsigned int index;
>   
>   	if (!fwspec)
> -		return;
> +		return -ENODEV;
>   
> +	if (domain == identity_domain || !domain)
> +		return 0;
> +
> +	as = to_smmu_as(domain);
> +	smmu = as->smmu;
>   	for (index = 0; index < fwspec->num_ids; index++) {
>   		tegra_smmu_disable(smmu, fwspec->ids[index], as->id);
>   		tegra_smmu_as_unprepare(smmu, as);
>   	}
> +	return 0;
>   }
>   
> +static struct iommu_domain_ops tegra_smmu_identity_ops = {
> +	.attach_dev = tegra_smmu_identity_attach,
> +};
> +
> +static struct iommu_domain tegra_smmu_identity_domain = {
> +	.type = IOMMU_DOMAIN_IDENTITY,
> +	.ops = &tegra_smmu_identity_ops,
> +};
> +
>   static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
>   			       u32 value)
>   {
> @@ -962,11 +978,22 @@ static int tegra_smmu_of_xlate(struct device *dev,
>   	return iommu_fwspec_add_ids(dev, &id, 1);
>   }
>   
> +static int tegra_smmu_def_domain_type(struct device *dev)
> +{
> +	/*
> +	 * FIXME: For now we want to run all translation in IDENTITY mode, due
> +	 * to some device quirks. Better would be to just quirk the troubled
> +	 * devices.
> +	 */
> +	return IOMMU_DOMAIN_IDENTITY;
> +}

Hope somebody can fix this later on.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu
diff mbox series

Patch

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 1cbf063ccf147a..f63f1d4f0bd10f 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -511,23 +511,39 @@  static int tegra_smmu_attach_dev(struct iommu_domain *domain,
 	return err;
 }
 
-static void tegra_smmu_set_platform_dma(struct device *dev)
+static int tegra_smmu_identity_attach(struct iommu_domain *identity_domain,
+				      struct device *dev)
 {
 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-	struct tegra_smmu_as *as = to_smmu_as(domain);
-	struct tegra_smmu *smmu = as->smmu;
+	struct tegra_smmu_as *as;
+	struct tegra_smmu *smmu;
 	unsigned int index;
 
 	if (!fwspec)
-		return;
+		return -ENODEV;
 
+	if (domain == identity_domain || !domain)
+		return 0;
+
+	as = to_smmu_as(domain);
+	smmu = as->smmu;
 	for (index = 0; index < fwspec->num_ids; index++) {
 		tegra_smmu_disable(smmu, fwspec->ids[index], as->id);
 		tegra_smmu_as_unprepare(smmu, as);
 	}
+	return 0;
 }
 
+static struct iommu_domain_ops tegra_smmu_identity_ops = {
+	.attach_dev = tegra_smmu_identity_attach,
+};
+
+static struct iommu_domain tegra_smmu_identity_domain = {
+	.type = IOMMU_DOMAIN_IDENTITY,
+	.ops = &tegra_smmu_identity_ops,
+};
+
 static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
 			       u32 value)
 {
@@ -962,11 +978,22 @@  static int tegra_smmu_of_xlate(struct device *dev,
 	return iommu_fwspec_add_ids(dev, &id, 1);
 }
 
+static int tegra_smmu_def_domain_type(struct device *dev)
+{
+	/*
+	 * FIXME: For now we want to run all translation in IDENTITY mode, due
+	 * to some device quirks. Better would be to just quirk the troubled
+	 * devices.
+	 */
+	return IOMMU_DOMAIN_IDENTITY;
+}
+
 static const struct iommu_ops tegra_smmu_ops = {
+	.identity_domain = &tegra_smmu_identity_domain,
+	.def_domain_type = &tegra_smmu_def_domain_type,
 	.domain_alloc = tegra_smmu_domain_alloc,
 	.probe_device = tegra_smmu_probe_device,
 	.device_group = tegra_smmu_device_group,
-	.set_platform_dma_ops = tegra_smmu_set_platform_dma,
 	.of_xlate = tegra_smmu_of_xlate,
 	.pgsize_bitmap = SZ_4K,
 	.default_domain_ops = &(const struct iommu_domain_ops) {