[PATCH v5 12/27] iommu/arm-smmu-v3: Start building a generic PASID layer

[Jason Gunthorpe]

Add arm_smmu_set_pasid()/arm_smmu_remove_pasid() which are to be used by
callers that already constructed the arm_smmu_cd they wish to program.

These functions will encapsulate the shared logic to setup a CD entry that
will be shared by SVA and S1 domain cases.

Prior fixes had already moved this logic most up into
__arm_smmu_sva_bind(), move it to it's final home.

This does not yet relieve the SVA restrictions:
 - The RID domain is a S1 domain
 - The programmed PASID is the mm_get_enqcmd_pasid()
 - Nothing changes while SVA is running (sva_enable)

Also, SVA invalidation will still iterate over the S1 domain's master
list.

Tested-by: Nicolin Chen <nicolinc at nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
---
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 39 +++++++++----------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 29 ++++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  6 +++
 3 files changed, 53 insertions(+), 21 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 159350a78d4cf9..e1fa2074c0b37b 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -416,12 +416,10 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 	arm_smmu_free_shared_cd(cd);
 }
 
-static int __arm_smmu_sva_bind(struct device *dev, ioasid_t pasid,
-			       struct mm_struct *mm)
+static int __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm,
+			       struct arm_smmu_cd *target)
 {
 	int ret;
-	struct arm_smmu_cd target;
-	struct arm_smmu_cd *cdptr;
 	struct arm_smmu_bond *bond;
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
@@ -448,19 +446,10 @@ static int __arm_smmu_sva_bind(struct device *dev, ioasid_t pasid,
 		goto err_free_bond;
 	}
 
-	cdptr = arm_smmu_get_cd_ptr(master, mm_get_enqcmd_pasid(mm));
-	if (!cdptr) {
-		ret = -ENOMEM;
-		goto err_put_notifier;
-	}
-	arm_smmu_make_sva_cd(&target, master, mm, bond->smmu_mn->cd->asid);
-	arm_smmu_write_cd_entry(master, pasid, cdptr, &target);
-
+	arm_smmu_make_sva_cd(target, master, mm, bond->smmu_mn->cd->asid);
 	list_add(&bond->list, &master->bonds);
 	return 0;
 
-err_put_notifier:
-	arm_smmu_mmu_notifier_put(bond->smmu_mn);
 err_free_bond:
 	kfree(bond);
 	return ret;
@@ -621,10 +610,9 @@ void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
 	struct arm_smmu_bond *bond = NULL, *t;
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 
+	arm_smmu_remove_pasid(master, to_smmu_domain(domain), id);
+
 	mutex_lock(&sva_lock);
-
-	arm_smmu_clear_cd(master, id);
-
 	list_for_each_entry(t, &master->bonds, list) {
 		if (t->mm == mm) {
 			bond = t;
@@ -643,17 +631,26 @@ void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
 static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain,
 				      struct device *dev, ioasid_t id)
 {
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 	int ret = 0;
 	struct mm_struct *mm = domain->mm;
+	struct arm_smmu_cd target;
 
 	if (mm_get_enqcmd_pasid(mm) != id)
 		return -EINVAL;
 
-	mutex_lock(&sva_lock);
-	ret = __arm_smmu_sva_bind(dev, id, mm);
-	mutex_unlock(&sva_lock);
+	if (!arm_smmu_get_cd_ptr(master, id))
+		return -ENOMEM;
 
-	return ret;
+	mutex_lock(&sva_lock);
+	ret = __arm_smmu_sva_bind(dev, mm, &target);
+	mutex_unlock(&sva_lock);
+	if (ret)
+		return ret;
+
+	/* This cannot fail since we preallocated the cdptr */
+	arm_smmu_set_pasid(master, to_smmu_domain(domain), id, &target);
+	return 0;
 }
 
 static void arm_smmu_sva_domain_free(struct iommu_domain *domain)
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 dfdd48cf217c4e..7a0be7dd719793 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2656,6 +2656,35 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	return 0;
 }
 
+static bool arm_smmu_is_s1_domain(struct iommu_domain *domain)
+{
+	if (!domain || !(domain->type & __IOMMU_DOMAIN_PAGING))
+		return false;
+	return to_smmu_domain(domain)->stage == ARM_SMMU_DOMAIN_S1;
+}
+
+int arm_smmu_set_pasid(struct arm_smmu_master *master,
+		       struct arm_smmu_domain *smmu_domain, ioasid_t pasid,
+		       const struct arm_smmu_cd *cd)
+{
+	struct arm_smmu_cd *cdptr;
+
+	if (!arm_smmu_is_s1_domain(iommu_get_domain_for_dev(master->dev)))
+		return -ENODEV;
+
+	cdptr = arm_smmu_get_cd_ptr(master, pasid);
+	if (!cdptr)
+		return -ENOMEM;
+	arm_smmu_write_cd_entry(master, pasid, cdptr, cd);
+	return 0;
+}
+
+void arm_smmu_remove_pasid(struct arm_smmu_master *master,
+			   struct arm_smmu_domain *smmu_domain, ioasid_t pasid)
+{
+	arm_smmu_clear_cd(master, pasid);
+}
+
 static int arm_smmu_attach_dev_ste(struct device *dev,
 				   struct arm_smmu_ste *ste)
 {
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 468cd33b80ac35..ab0a6587e07ec8 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -753,6 +753,12 @@ void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
 			     struct arm_smmu_cd *cdptr,
 			     const struct arm_smmu_cd *target);
 
+int arm_smmu_set_pasid(struct arm_smmu_master *master,
+		       struct arm_smmu_domain *smmu_domain, ioasid_t pasid,
+		       const struct arm_smmu_cd *cd);
+void arm_smmu_remove_pasid(struct arm_smmu_master *master,
+			   struct arm_smmu_domain *smmu_domain, ioasid_t pasid);
+
 void arm_smmu_tlb_inv_asid(struct arm_smmu_device *smmu, u16 asid);
 void arm_smmu_tlb_inv_range_asid(unsigned long iova, size_t size, int asid,
 				 size_t granule, bool leaf,
-- 
2.43.2