[PATCH v2 07/11] iommu/arm-smmu-v3: Introduce arm_vsmmu_atc_inv_domain()

[Nicolin Chen]

Currently, all nested domains that enable ATS (i.e. nested_ats_flush) are
added to the devices list in the S2 parent domain via a master_domain. On
the other hand, an S2 parent domain can be shared across vSMMU instances.
So, storing all devices behind different vSMMU isntances into a shared S2
parent domain apparently isn't ideal.

Add a new per-vSMMU ats_devices list (with a pairing lock), which will be
stored the devices if their ATS features are enabled.

Using this ats_devices list, add an arm_vsmmu_atc_inv_domain() helper, for
the s2_parent invalidation routines to proceed ATC invalidation properly,
which sends an ATC invalidation request to all the devices on the list.

Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  6 +++
 .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c     | 45 +++++++++++++++++++
 2 files changed, 51 insertions(+)

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 7d76d8ac9acc..d130d723cc33 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -840,6 +840,7 @@ struct arm_smmu_master {
 	bool				sva_enabled;
 	bool				iopf_enabled;
 	unsigned int			ssid_bits;
+	struct list_head		devices_elm; /* vsmmu->ats_devices */
 };
 
 /* SMMU private data for an IOMMU domain */
@@ -1086,6 +1087,11 @@ struct arm_vsmmu {
 	struct arm_smmu_domain *s2_parent;
 	u16 vmid;
 	struct list_head vsmmus_elm; /* arm_smmu_domain::vsmmus::list */
+	/* List of struct arm_smmu_master that enables ATS */
+	struct {
+		struct list_head list;
+		spinlock_t lock;
+	} ats_devices;
 };
 
 #if IS_ENABLED(CONFIG_ARM_SMMU_V3_IOMMUFD)
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 45ba68a1b59a..4730ff56cf04 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
@@ -30,6 +30,41 @@ void *arm_smmu_hw_info(struct device *dev, u32 *length, u32 *type)
 	return info;
 }
 
+static void arm_vsmmu_cmdq_batch_add_atc_inv(struct arm_vsmmu *vsmmu,
+					     struct arm_smmu_master *master,
+					     struct arm_smmu_cmdq_batch *cmds,
+					     struct arm_smmu_cmdq_ent *cmd)
+{
+	int i;
+
+	lockdep_assert_held(&vsmmu->ats_devices.lock);
+
+	arm_smmu_atc_inv_to_cmd(IOMMU_NO_PASID, 0, 0, cmd);
+	for (i = 0; i < master->num_streams; i++) {
+		cmd->atc.sid = master->streams[i].id;
+		arm_smmu_cmdq_batch_add(vsmmu->smmu, cmds, cmd);
+	}
+}
+
+static int arm_vsmmu_atc_inv_domain(struct arm_vsmmu *vsmmu, unsigned long iova,
+				    size_t size)
+{
+	struct arm_smmu_cmdq_ent cmd = { .opcode = CMDQ_OP_ATC_INV };
+	struct arm_smmu_master *master, *next;
+	struct arm_smmu_cmdq_batch cmds;
+	unsigned long flags;
+
+	arm_smmu_cmdq_batch_init(vsmmu->smmu, &cmds, &cmd);
+
+	spin_lock_irqsave(&vsmmu->ats_devices.lock, flags);
+	list_for_each_entry_safe(master, next, &vsmmu->ats_devices.list,
+				 devices_elm)
+		arm_vsmmu_cmdq_batch_add_atc_inv(vsmmu, master, &cmds, &cmd);
+	spin_unlock_irqrestore(&vsmmu->ats_devices.lock, flags);
+
+	return arm_smmu_cmdq_batch_submit(vsmmu->smmu, &cmds);
+}
+
 void arm_smmu_s2_parent_tlb_inv_domain(struct arm_smmu_domain *s2_parent)
 {
 	struct arm_vsmmu *vsmmu, *next;
@@ -39,6 +74,7 @@ void arm_smmu_s2_parent_tlb_inv_domain(struct arm_smmu_domain *s2_parent)
 	list_for_each_entry_safe(vsmmu, next, &s2_parent->vsmmus.list,
 				 vsmmus_elm) {
 		arm_smmu_tlb_inv_vmid(vsmmu->smmu, vsmmu->vmid);
+		arm_vsmmu_atc_inv_domain(vsmmu, 0, 0);
 	}
 	spin_unlock_irqrestore(&s2_parent->vsmmus.lock, flags);
 }
@@ -62,6 +98,11 @@ void arm_smmu_s2_parent_tlb_inv_range(struct arm_smmu_domain *s2_parent,
 		cmd.opcode = CMDQ_OP_TLBI_S2_IPA;
 		__arm_smmu_tlb_inv_range(vsmmu->smmu, &cmd, iova, size, granule,
 					 &s2_parent->domain);
+		/*
+		 * Unfortunately, this can't be leaf-only since we may have
+		 * zapped an entire table.
+		 */
+		arm_vsmmu_atc_inv_domain(vsmmu, iova, size);
 	}
 	spin_unlock_irqrestore(&s2_parent->vsmmus.lock, flags);
 }
@@ -76,6 +117,7 @@ static void arm_vsmmu_destroy(struct iommufd_viommu *viommu)
 	spin_unlock_irqrestore(&vsmmu->s2_parent->vsmmus.lock, flags);
 	/* Must flush S2 vmid after delinking vSMMU */
 	arm_smmu_tlb_inv_vmid(vsmmu->smmu, vsmmu->vmid);
+	arm_vsmmu_atc_inv_domain(vsmmu, 0, 0);
 }
 
 static void arm_smmu_make_nested_cd_table_ste(
@@ -487,6 +529,9 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
 	list_add_tail(&vsmmu->vsmmus_elm, &s2_parent->vsmmus.list);
 	spin_unlock_irqrestore(&s2_parent->vsmmus.lock, flags);
 
+	INIT_LIST_HEAD(&vsmmu->ats_devices.list);
+	spin_lock_init(&vsmmu->ats_devices.lock);
+
 	return &vsmmu->core;
 }
 
-- 
2.43.0