[PATCH v3 08/10] iommu/arm-smmu-v3: Allocate INV_TYPE_S2_VMID_VSMMU in arm_vsmmu_init

[Nicolin Chen]

VMID owned by a vSMMU should be allocated in the viommu_init callback for
 - a straightforward lifecycle for a VMID used by a vSMMU
 - HW like tegra241-cmdqv needs to setup VINTF with the VMID

Allocate/free a VMID in arm_vsmmu_init/destroy(). This decouples the VMID
owned by vSMMU from the VMID living in the S2 parent domain (s2_cfg.vmid).

Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  1 +
 .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c     | 24 +++++++++++++++++--
 .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c    |  1 +
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index b821241f73c7a..db6568f1b2dd6 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -1213,6 +1213,7 @@ size_t arm_smmu_get_viommu_size(struct device *dev,
 int arm_vsmmu_init(struct iommufd_viommu *viommu,
 		   struct iommu_domain *parent_domain,
 		   const struct iommu_user_data *user_data);
+void arm_vsmmu_destroy(struct iommufd_viommu *viommu);
 int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,
 				    struct arm_smmu_nested_domain *nested_domain);
 void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index a77c60321203c..dc638c38515e4 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -406,7 +406,20 @@ int arm_vsmmu_cache_invalidate(struct iommufd_viommu *viommu,
 	return ret;
 }
 
+void arm_vsmmu_destroy(struct iommufd_viommu *viommu)
+{
+	struct arm_vsmmu *vsmmu = container_of(viommu, struct arm_vsmmu, core);
+
+	guard(mutex)(&arm_smmu_asid_lock);
+	/*
+	 * arm_smmu_iotlb_tag_free() must have flushed the IOTLB with the VMID,
+	 * but it did not free the VMID to align its lifecycle with the vSMMU.
+	 */
+	ida_free(&vsmmu->smmu->vmid_map, vsmmu->vmid);
+}
+
 static const struct iommufd_viommu_ops arm_vsmmu_ops = {
+	.destroy = arm_vsmmu_destroy,
 	.alloc_domain_nested = arm_vsmmu_alloc_domain_nested,
 	.cache_invalidate = arm_vsmmu_cache_invalidate,
 };
@@ -456,14 +469,21 @@ int arm_vsmmu_init(struct iommufd_viommu *viommu,
 	struct arm_smmu_device *smmu =
 		container_of(viommu->iommu_dev, struct arm_smmu_device, iommu);
 	struct arm_smmu_domain *s2_parent = to_smmu_domain(parent_domain);
+	int id;
 
 	if (s2_parent->smmu != smmu)
 		return -EINVAL;
 
+	mutex_lock(&arm_smmu_asid_lock);
+	id = ida_alloc_range(&smmu->vmid_map, 1, (1 << smmu->vmid_bits) - 1,
+			     GFP_KERNEL);
+	mutex_unlock(&arm_smmu_asid_lock);
+	if (id < 0)
+		return id;
+
+	vsmmu->vmid = id;
 	vsmmu->smmu = smmu;
 	vsmmu->s2_parent = s2_parent;
-	/* FIXME Move VMID allocation from the S2 domain allocation to here */
-	vsmmu->vmid = s2_parent->s2_cfg.vmid;
 
 	if (viommu->type == IOMMU_VIOMMU_TYPE_ARM_SMMUV3) {
 		viommu->ops = &arm_vsmmu_ops;
diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
index 6fe5563eaf9eb..92845fabd0dec 100644
--- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
+++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
@@ -1152,6 +1152,7 @@ static void tegra241_cmdqv_destroy_vintf_user(struct iommufd_viommu *viommu)
 		iommufd_viommu_destroy_mmap(&vintf->vsmmu.core,
 					    vintf->mmap_offset);
 	tegra241_cmdqv_remove_vintf(vintf->cmdqv, vintf->idx);
+	arm_vsmmu_destroy(viommu);
 }
 
 static void tegra241_vintf_destroy_vsid(struct iommufd_vdevice *vdev)
-- 
2.43.0