[PATCH v2 2/5] iommu: Introduce mm_get_pasid() helper function

[Tina Zhang <tina.zhang@intel.com>]

Use the helper function mm_get_pasid() to get a mm assigned pasid
value. The motivation is to replace mm->pasid with an iommu private
data structure that is introduced in a later patch.

v2:
- Update commit message
- Let mm_get_enqcmd_pasid() call mm_get_pasid() to get pasid

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 12 ++++++------
 drivers/iommu/intel/svm.c                       |  8 ++++----
 drivers/iommu/iommu-sva.c                       | 14 +++++++-------
 include/linux/iommu.h                           | 10 +++++++++-
 4 files changed, 26 insertions(+), 18 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 a5a63b1c947eb..0b455654d3650 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
@@ -204,7 +204,7 @@ static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
 	if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_BTM))
 		arm_smmu_tlb_inv_range_asid(start, size, smmu_mn->cd->asid,
 					    PAGE_SIZE, false, smmu_domain);
-	arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, start, size);
+	arm_smmu_atc_inv_domain(smmu_domain, mm_get_pasid(mm), start, size);
 }
 
 static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
@@ -222,10 +222,10 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 	 * DMA may still be running. Keep the cd valid to avoid C_BAD_CD events,
 	 * but disable translation.
 	 */
-	arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, &quiet_cd);
+	arm_smmu_write_ctx_desc(smmu_domain, mm_get_pasid(mm), &quiet_cd);
 
 	arm_smmu_tlb_inv_asid(smmu_domain->smmu, smmu_mn->cd->asid);
-	arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+	arm_smmu_atc_inv_domain(smmu_domain, mm_get_pasid(mm), 0, 0);
 
 	smmu_mn->cleared = true;
 	mutex_unlock(&sva_lock);
@@ -279,7 +279,7 @@ arm_smmu_mmu_notifier_get(struct arm_smmu_domain *smmu_domain,
 		goto err_free_cd;
 	}
 
-	ret = arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, cd);
+	ret = arm_smmu_write_ctx_desc(smmu_domain, mm_get_pasid(mm), cd);
 	if (ret)
 		goto err_put_notifier;
 
@@ -304,7 +304,7 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 		return;
 
 	list_del(&smmu_mn->list);
-	arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, NULL);
+	arm_smmu_write_ctx_desc(smmu_domain, mm_get_pasid(mm), NULL);
 
 	/*
 	 * If we went through clear(), we've already invalidated, and no
@@ -312,7 +312,7 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 	 */
 	if (!smmu_mn->cleared) {
 		arm_smmu_tlb_inv_asid(smmu_domain->smmu, cd->asid);
-		arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+		arm_smmu_atc_inv_domain(smmu_domain, mm_get_pasid(mm), 0, 0);
 	}
 
 	/* Frees smmu_mn */
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index e95b339e9cdc0..e6377cff6a935 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -306,13 +306,13 @@ static int intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev,
 	unsigned long sflags;
 	int ret = 0;
 
-	svm = pasid_private_find(mm->pasid);
+	svm = pasid_private_find(mm_get_pasid(mm));
 	if (!svm) {
 		svm = kzalloc(sizeof(*svm), GFP_KERNEL);
 		if (!svm)
 			return -ENOMEM;
 
-		svm->pasid = mm->pasid;
+		svm->pasid = mm_get_pasid(mm);
 		svm->mm = mm;
 		INIT_LIST_HEAD_RCU(&svm->devs);
 
@@ -350,7 +350,7 @@ static int intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev,
 
 	/* Setup the pasid table: */
 	sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
-	ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid,
+	ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm_get_pasid(mm),
 					    FLPT_DEFAULT_DID, sflags);
 	if (ret)
 		goto free_sdev;
@@ -364,7 +364,7 @@ static int intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev,
 free_svm:
 	if (list_empty(&svm->devs)) {
 		mmu_notifier_unregister(&svm->notifier, mm);
-		pasid_private_remove(mm->pasid);
+		pasid_private_remove(mm_get_pasid(mm));
 		kfree(svm);
 	}
 
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 05c0fb2acbc44..0a4a1ed40814c 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -28,7 +28,7 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma
 	mutex_lock(&iommu_sva_lock);
 	/* Is a PASID already associated with this mm? */
 	if (mm_valid_pasid(mm)) {
-		if (mm->pasid < min || mm->pasid > max)
+		if (mm_get_pasid(mm) < min || mm_get_pasid(mm) > max)
 			ret = -EOVERFLOW;
 		goto out;
 	}
@@ -71,7 +71,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
 	if (!max_pasids)
 		return ERR_PTR(-EOPNOTSUPP);
 
-	/* Allocate mm->pasid if necessary. */
+	/* Allocate pasid if necessary. */
 	ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1);
 	if (ret)
 		return ERR_PTR(ret);
@@ -82,7 +82,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
 
 	mutex_lock(&iommu_sva_lock);
 	/* Search for an existing domain. */
-	domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid,
+	domain = iommu_get_domain_for_dev_pasid(dev, mm_get_pasid(mm),
 						IOMMU_DOMAIN_SVA);
 	if (IS_ERR(domain)) {
 		ret = PTR_ERR(domain);
@@ -101,7 +101,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
 		goto out_unlock;
 	}
 
-	ret = iommu_attach_device_pasid(domain, dev, mm->pasid);
+	ret = iommu_attach_device_pasid(domain, dev, mm_get_pasid(mm));
 	if (ret)
 		goto out_free_domain;
 	domain->users = 1;
@@ -133,7 +133,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
 void iommu_sva_unbind_device(struct iommu_sva *handle)
 {
 	struct iommu_domain *domain = handle->domain;
-	ioasid_t pasid = domain->mm->pasid;
+	ioasid_t pasid = mm_get_pasid(domain->mm);
 	struct device *dev = handle->dev;
 
 	mutex_lock(&iommu_sva_lock);
@@ -150,7 +150,7 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 {
 	struct iommu_domain *domain = handle->domain;
 
-	return domain->mm->pasid;
+	return mm_get_pasid(domain->mm);
 }
 EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
 
@@ -217,5 +217,5 @@ void mm_pasid_drop(struct mm_struct *mm)
 	if (likely(!mm_valid_pasid(mm)))
 		return;
 
-	ida_free(&iommu_global_pasid_ida, mm->pasid);
+	ida_free(&iommu_global_pasid_ida, mm_get_pasid(mm));
 }
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ab9919746fd33..ab8784dfdbd98 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1180,10 +1180,14 @@ static inline bool mm_valid_pasid(struct mm_struct *mm)
 {
 	return mm->pasid != IOMMU_PASID_INVALID;
 }
-static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm)
+static inline u32 mm_get_pasid(struct mm_struct *mm)
 {
 	return mm->pasid;
 }
+static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm)
+{
+	return mm_get_pasid(mm);
+}
 void mm_pasid_drop(struct mm_struct *mm);
 struct iommu_sva *iommu_sva_bind_device(struct device *dev,
 					struct mm_struct *mm);
@@ -1206,6 +1210,10 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 }
 static inline void mm_pasid_init(struct mm_struct *mm) {}
 static inline bool mm_valid_pasid(struct mm_struct *mm) { return false; }
+static inline u32 mm_get_pasid(struct mm_struct *mm)
+{
+	return IOMMU_PASID_INVALID;
+}
 static inline u32 mm_get_enqcmd_pasid(struct mm_struct *mm)
 {
 	return IOMMU_PASID_INVALID;
-- 
2.34.1