[PATCH v2 17/18] iommu/arm-smmu-v3-sva: Alloc notifier for {smmu,mn}

[Michael Shavit]

The arm_smmu_nofitier for an mn can be shared across all devices with
the same upstream smmu. This breaks the last remaining explicit
dependency on the device's primary domain in arm-smmu-v3-sva.

Signed-off-by: Michael Shavit <mshavit@xxxxxxxxxx>
---
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c    | 18 +++++++-----------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c    |  2 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h    |  4 ++--
 3 files changed, 10 insertions(+), 14 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 9a2da579c3563..3e49838e4f55c 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
@@ -258,17 +258,16 @@ static const struct mmu_notifier_ops arm_smmu_mmu_notifier_ops = {
 	.free_notifier		= arm_smmu_mmu_notifier_free,
 };
 
-/* Allocate or get existing MMU notifier for this {domain, mm} pair */
+/* Allocate or get existing MMU notifier for this {smmu, mm} pair */
 static struct arm_smmu_mmu_notifier *
 arm_smmu_mmu_notifier_get(struct arm_smmu_device *smmu,
-			  struct arm_smmu_domain *smmu_domain,
 			  struct mm_struct *mm)
 {
 	int ret;
 	struct arm_smmu_ctx_desc *cd;
 	struct arm_smmu_mmu_notifier *smmu_mn;
 
-	list_for_each_entry(smmu_mn, &smmu_domain->mmu_notifiers, list) {
+	list_for_each_entry(smmu_mn, &smmu->mmu_notifiers, list) {
 		if (smmu_mn->mn.mm == mm) {
 			refcount_inc(&smmu_mn->refs);
 			return smmu_mn;
@@ -296,9 +295,8 @@ arm_smmu_mmu_notifier_get(struct arm_smmu_device *smmu,
 	}
 	arm_smmu_init_shared_cd_domain(smmu, &smmu_mn->domain, cd);
 
-	list_add(&smmu_mn->list, &smmu_domain->mmu_notifiers);
+	list_add(&smmu_mn->list, &smmu->mmu_notifiers);
 	return smmu_mn;
-
 err_free_cd:
 	arm_smmu_free_shared_cd(cd);
 	return ERR_PTR(ret);
@@ -314,7 +312,6 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 		return;
 
 	list_del(&smmu_mn->list);
-
 	/*
 	 * If we went through clear(), we've already invalidated, and no
 	 * new TLB entry can have been formed.
@@ -331,18 +328,17 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 
 static int __arm_smmu_sva_bind(struct device *dev,
 			       struct arm_smmu_sva_domain *sva_domain,
-			       struct mm_struct *mm)
+			       struct mm_struct *mm,
+			       ioasid_t id)
 {
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
-	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+	struct arm_smmu_domain *smmu_domain;
 	int ret;
 
 	if (!master || !master->sva_enabled)
 		return -ENODEV;
 
 	sva_domain->smmu_mn = arm_smmu_mmu_notifier_get(master->smmu,
-							smmu_domain,
 							mm);
 	if (IS_ERR(sva_domain->smmu_mn)) {
 		sva_domain->smmu_mn = NULL;
@@ -533,7 +529,7 @@ static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain,
 	struct mm_struct *mm = domain->mm;
 
 	mutex_lock(&sva_lock);
-	ret = __arm_smmu_sva_bind(dev, to_sva_domain(domain), mm);
+	ret = __arm_smmu_sva_bind(dev, to_sva_domain(domain), mm, id);
 	mutex_unlock(&sva_lock);
 
 	return ret;
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 3c5ff4f58934a..e68c5264c6171 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2058,7 +2058,6 @@ static void arm_smmu_init_smmu_domain(struct arm_smmu_domain *smmu_domain)
 	mutex_init(&smmu_domain->init_mutex);
 	INIT_LIST_HEAD(&smmu_domain->attached_domains);
 	spin_lock_init(&smmu_domain->attached_domains_lock);
-	INIT_LIST_HEAD(&smmu_domain->mmu_notifiers);
 }
 
 static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
@@ -2859,6 +2858,7 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
 		goto err_free_master;
 	}
 
+	INIT_LIST_HEAD(&smmu->mmu_notifiers);
 	return &smmu->iommu;
 
 err_free_master:
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 2c33c0461036d..041b0e532ac3d 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -674,6 +674,8 @@ struct arm_smmu_device {
 
 	struct rb_root			streams;
 	struct mutex			streams_mutex;
+
+	struct list_head		mmu_notifiers;
 };
 
 struct arm_smmu_stream {
@@ -737,8 +739,6 @@ struct arm_smmu_domain {
 
 	struct list_head			attached_domains;
 	spinlock_t				attached_domains_lock;
-
-	struct list_head			mmu_notifiers;
 };
 
 static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
-- 
2.41.0.rc0.172.g3f132b7071-goog