cleanup the code a bit. free_iova doesn't need lock twice.
Cc: Joerg Roedel <[email protected]>
Cc: David Woodhouse <[email protected]>
Signed-off-by: Shaohua Li <[email protected]>
---
drivers/iommu/iova.c | 62 +++++++++++++++++++++++++++++++---------------------
1 file changed, 37 insertions(+), 25 deletions(-)
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 5c86c5c..bb8a328 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -362,35 +362,17 @@ alloc_iova(struct iova_domain *iovad, unsigned long size,
}
EXPORT_SYMBOL_GPL(alloc_iova);
-/**
- * find_iova - find's an iova for a given pfn
- * @iovad: - iova domain in question.
- * @pfn: - page frame number
- * This function finds and returns an iova belonging to the
- * given doamin which matches the given pfn.
- */
-struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
+static struct iova *__find_iova(struct iova_domain *iovad, unsigned long pfn)
{
- unsigned long flags;
struct rb_node *node;
- /* Take the lock so that no other thread is manipulating the rbtree */
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
node = iovad->rbroot.rb_node;
while (node) {
struct iova *iova = container_of(node, struct iova, node);
/* If pfn falls within iova's range, return iova */
- if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- /* We are not holding the lock while this iova
- * is referenced by the caller as the same thread
- * which called this function also calls __free_iova()
- * and it is by design that only one thread can possibly
- * reference a particular iova and hence no conflict.
- */
+ if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi))
return iova;
- }
if (pfn < iova->pfn_lo)
node = node->rb_left;
@@ -398,9 +380,33 @@ struct iova *find_iova(struct iova_domain *iovad, unsigned
long pfn)
node = node->rb_right;
}
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
return NULL;
}
+
+/**
+ * find_iova - find's an iova for a given pfn
+ * @iovad: - iova domain in question.
+ * @pfn: - page frame number
+ * This function finds and returns an iova belonging to the
+ * given doamin which matches the given pfn.
+ */
+struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
+{
+ unsigned long flags;
+ struct iova *iova;
+
+ /* Take the lock so that no other thread is manipulating the rbtree */
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ iova = __find_iova(iovad, pfn);
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ /* We are not holding the lock while this iova
+ * is referenced by the caller as the same thread
+ * which called this function also calls __free_iova()
+ * and it is by design that only one thread can possibly
+ * reference a particular iova and hence no conflict.
+ */
+ return iova;
+}
EXPORT_SYMBOL_GPL(find_iova);
/**
@@ -432,11 +438,17 @@ EXPORT_SYMBOL_GPL(__free_iova);
void
free_iova(struct iova_domain *iovad, unsigned long pfn)
{
- struct iova *iova = find_iova(iovad, pfn);
-
- if (iova)
- __free_iova(iovad, iova);
+ unsigned long flags;
+ struct iova *iova;
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ iova = __find_iova(iovad, pfn);
+ if (iova) {
+ __cached_rbnode_delete_update(iovad, iova);
+ rb_erase(&iova->node, &iovad->rbroot);
+ }
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ free_iova_mem(iova);
}
EXPORT_SYMBOL_GPL(free_iova);
--
2.4.6
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