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-rw-r--r--drivers/iommu/intel/iommu.c4
-rw-r--r--drivers/iommu/intel/svm.c6
-rw-r--r--drivers/iommu/ioasid.c38
-rw-r--r--include/linux/ioasid.h10
4 files changed, 47 insertions, 11 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 1b1ca63e6bbe..8b26223979a2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5198,7 +5198,7 @@ static void auxiliary_unlink_device(struct dmar_domain *domain,
domain->auxd_refcnt--;
if (!domain->auxd_refcnt && domain->default_pasid > 0)
- ioasid_free(domain->default_pasid);
+ ioasid_put(domain->default_pasid);
}
static int aux_domain_add_dev(struct dmar_domain *domain,
@@ -5259,7 +5259,7 @@ attach_failed:
spin_unlock(&iommu->lock);
spin_unlock_irqrestore(&device_domain_lock, flags);
if (!domain->auxd_refcnt && domain->default_pasid > 0)
- ioasid_free(domain->default_pasid);
+ ioasid_put(domain->default_pasid);
return ret;
}
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 3242ebd0bca3..4fa248b98031 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -598,7 +598,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
if (mm) {
ret = mmu_notifier_register(&svm->notifier, mm);
if (ret) {
- ioasid_free(svm->pasid);
+ ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
@@ -616,7 +616,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
if (ret) {
if (mm)
mmu_notifier_unregister(&svm->notifier, mm);
- ioasid_free(svm->pasid);
+ ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
@@ -689,7 +689,7 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
- ioasid_free(svm->pasid);
+ ioasid_put(svm->pasid);
if (svm->mm) {
mmu_notifier_unregister(&svm->notifier, svm->mm);
/* Clear mm's pasid. */
diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
index 0f8dd377aada..50ee27bbd04e 100644
--- a/drivers/iommu/ioasid.c
+++ b/drivers/iommu/ioasid.c
@@ -2,7 +2,7 @@
/*
* I/O Address Space ID allocator. There is one global IOASID space, split into
* subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and
- * free IOASIDs with ioasid_alloc and ioasid_free.
+ * free IOASIDs with ioasid_alloc and ioasid_put.
*/
#include <linux/ioasid.h>
#include <linux/module.h>
@@ -15,6 +15,7 @@ struct ioasid_data {
struct ioasid_set *set;
void *private;
struct rcu_head rcu;
+ refcount_t refs;
};
/*
@@ -314,6 +315,7 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
data->set = set;
data->private = private;
+ refcount_set(&data->refs, 1);
/*
* Custom allocator needs allocator data to perform platform specific
@@ -346,11 +348,34 @@ exit_free:
EXPORT_SYMBOL_GPL(ioasid_alloc);
/**
- * ioasid_free - Free an IOASID
+ * ioasid_get - obtain a reference to the IOASID
+ */
+void ioasid_get(ioasid_t ioasid)
+{
+ struct ioasid_data *ioasid_data;
+
+ spin_lock(&ioasid_allocator_lock);
+ ioasid_data = xa_load(&active_allocator->xa, ioasid);
+ if (ioasid_data)
+ refcount_inc(&ioasid_data->refs);
+ else
+ WARN_ON(1);
+ spin_unlock(&ioasid_allocator_lock);
+}
+EXPORT_SYMBOL_GPL(ioasid_get);
+
+/**
+ * ioasid_put - Release a reference to an ioasid
* @ioasid: the ID to remove
+ *
+ * Put a reference to the IOASID, free it when the number of references drops to
+ * zero.
+ *
+ * Return: %true if the IOASID was freed, %false otherwise.
*/
-void ioasid_free(ioasid_t ioasid)
+bool ioasid_put(ioasid_t ioasid)
{
+ bool free = false;
struct ioasid_data *ioasid_data;
spin_lock(&ioasid_allocator_lock);
@@ -360,6 +385,10 @@ void ioasid_free(ioasid_t ioasid)
goto exit_unlock;
}
+ free = refcount_dec_and_test(&ioasid_data->refs);
+ if (!free)
+ goto exit_unlock;
+
active_allocator->ops->free(ioasid, active_allocator->ops->pdata);
/* Custom allocator needs additional steps to free the xa element */
if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) {
@@ -369,8 +398,9 @@ void ioasid_free(ioasid_t ioasid)
exit_unlock:
spin_unlock(&ioasid_allocator_lock);
+ return free;
}
-EXPORT_SYMBOL_GPL(ioasid_free);
+EXPORT_SYMBOL_GPL(ioasid_put);
/**
* ioasid_find - Find IOASID data
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index 6f000d7a0ddc..e9dacd4b9f6b 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -34,7 +34,8 @@ struct ioasid_allocator_ops {
#if IS_ENABLED(CONFIG_IOASID)
ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
void *private);
-void ioasid_free(ioasid_t ioasid);
+void ioasid_get(ioasid_t ioasid);
+bool ioasid_put(ioasid_t ioasid);
void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
bool (*getter)(void *));
int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
@@ -48,10 +49,15 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
return INVALID_IOASID;
}
-static inline void ioasid_free(ioasid_t ioasid)
+static inline void ioasid_get(ioasid_t ioasid)
{
}
+static inline bool ioasid_put(ioasid_t ioasid)
+{
+ return false;
+}
+
static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
bool (*getter)(void *))
{