[PATCH v3 29/29] iommu/arm-smmu-v3-kvm: Add IOMMU ops

[Mostafa Saleh]

Register the SMMUv3 through IOMMU ops, that only support identity
domains. This allows the driver to know which device are currently used
to properly enable/disable then.

Signed-off-by: Mostafa Saleh <smostafa at google.com>
---
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c   | 92 ++++++++++++++++++-
 1 file changed, 91 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
index 2e51e211250d..d7b2a50a4cb2 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
@@ -96,6 +96,95 @@ static int kvm_arm_smmu_device_reset(struct host_arm_smmu_device *host_smmu)
 	return 0;
 }
 
+static struct platform_driver kvm_arm_smmu_driver;
+static struct arm_smmu_device *
+kvm_arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
+{
+	struct device *dev;
+
+	dev = driver_find_device_by_fwnode(&kvm_arm_smmu_driver.driver, fwnode);
+	put_device(dev);
+	return dev ? dev_get_drvdata(dev) : NULL;
+}
+
+static struct iommu_device *kvm_arm_smmu_probe_device(struct device *dev)
+{
+	struct arm_smmu_device *smmu;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+	if (WARN_ON_ONCE(dev_iommu_priv_get(dev)))
+		return ERR_PTR(-EBUSY);
+
+	smmu = kvm_arm_smmu_get_by_fwnode(fwspec->iommu_fwnode);
+	if (!smmu)
+		return ERR_PTR(-ENODEV);
+
+	dev_iommu_priv_set(dev, smmu);
+	return &smmu->iommu;
+}
+
+static void kvm_arm_smmu_release_device(struct device *dev)
+{
+	int i;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+	struct arm_smmu_device *smmu = dev_iommu_priv_get(dev);
+	struct host_arm_smmu_device *host_smmu = smmu_to_host(smmu);
+
+	for (i = 0; i < fwspec->num_ids; i++) {
+		int sid = fwspec->ids[i];
+
+		kvm_call_hyp_nvhe(__pkvm_iommu_disable_dev, host_smmu->id, sid);
+	}
+}
+
+static phys_addr_t kvm_arm_smmu_iova_to_phys(struct iommu_domain *domain,
+					     dma_addr_t iova)
+{
+	return iova;
+}
+
+static int kvm_arm_smmu_attach_dev(struct iommu_domain *domain,
+				   struct device *dev)
+{
+	int i, ret = 0;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+	struct arm_smmu_device *smmu = dev_iommu_priv_get(dev);
+	struct host_arm_smmu_device *host_smmu = smmu_to_host(smmu);
+
+	for (i = 0; i < fwspec->num_ids; i++) {
+		int sid = fwspec->ids[i];
+
+		ret = kvm_call_hyp_nvhe(__pkvm_iommu_enable_dev, host_smmu->id, sid);
+		if (ret)
+			goto out_err;
+	}
+	return ret;
+out_err:
+	while (i--)
+		kvm_call_hyp_nvhe(__pkvm_iommu_disable_dev, host_smmu->id, fwspec->ids[i]);
+
+	return ret;
+}
+
+static struct iommu_domain kvm_arm_smmu_def_domain = {
+	.type = IOMMU_DOMAIN_IDENTITY,
+	.ops = &(const struct iommu_domain_ops) {
+		.attach_dev	= kvm_arm_smmu_attach_dev,
+		.iova_to_phys	= kvm_arm_smmu_iova_to_phys,
+	}
+};
+
+static struct iommu_ops kvm_arm_smmu_ops = {
+	.device_group		= arm_smmu_device_group,
+	.of_xlate		= arm_smmu_of_xlate,
+	.get_resv_regions	= arm_smmu_get_resv_regions,
+	.probe_device		= kvm_arm_smmu_probe_device,
+	.release_device		= kvm_arm_smmu_release_device,
+	.pgsize_bitmap		= -1UL,
+	.owner			= THIS_MODULE,
+	.default_domain 	= &kvm_arm_smmu_def_domain,
+};
+
 static int kvm_arm_smmu_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -170,7 +259,7 @@ static int kvm_arm_smmu_probe(struct platform_device *pdev)
 	hyp_smmu->features = smmu->features;
 	kvm_arm_smmu_cur++;
 
-	return 0;
+	return arm_smmu_register_iommu(smmu, &kvm_arm_smmu_ops, ioaddr);
 }
 
 static void kvm_arm_smmu_remove(struct platform_device *pdev)
@@ -184,6 +273,7 @@ static void kvm_arm_smmu_remove(struct platform_device *pdev)
 	 */
 	arm_smmu_device_disable(smmu);
 	arm_smmu_update_gbpa(smmu, host_smmu->boot_gbpa, GBPA_ABORT);
+	arm_smmu_unregister_iommu(smmu);
 }
 
 static const struct of_device_id arm_smmu_of_match[] = {
-- 
2.50.1.552.g942d659e1b-goog