2 files changed, 30 insertions, 33 deletions

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 20be9a8b3188..c6f5a22f8d20 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -48,6 +48,7 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule,
 
         spin_lock_init(&iovad->iova_rbtree_lock);
         iovad->rbroot = RB_ROOT;
+        iovad->cached_node = NULL;
         iovad->cached32_node = NULL;
         iovad->granule = granule;
         iovad->start_pfn = start_pfn;
@@ -110,48 +111,44 @@ EXPORT_SYMBOL_GPL(init_iova_flush_queue);
 static struct rb_node *
 __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
 {
-        if ((*limit_pfn > iovad->dma_32bit_pfn) ||
-                (iovad->cached32_node == NULL))
+        struct rb_node *cached_node = NULL;
+        struct iova *curr_iova;
+
+        if (*limit_pfn <= iovad->dma_32bit_pfn)
+                cached_node = iovad->cached32_node;
+        if (!cached_node)
+                cached_node = iovad->cached_node;
+        if (!cached_node)
                 return rb_last(&iovad->rbroot);
-        else {
-                struct rb_node *prev_node = rb_prev(iovad->cached32_node);
-                struct iova *curr_iova =
-                        rb_entry(iovad->cached32_node, struct iova, node);
-                *limit_pfn = curr_iova->pfn_lo;
-                return prev_node;
-        }
+
+        curr_iova = rb_entry(cached_node, struct iova, node);
+        *limit_pfn = min(*limit_pfn, curr_iova->pfn_lo);
+
+        return rb_prev(cached_node);
 }
 
 static void
-__cached_rbnode_insert_update(struct iova_domain *iovad,
-        unsigned long limit_pfn, struct iova *new)
+__cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new)
 {
-        if (limit_pfn != iovad->dma_32bit_pfn)
-                return;
-        iovad->cached32_node = &new->node;
+        if (new->pfn_hi < iovad->dma_32bit_pfn)
+                iovad->cached32_node = &new->node;
+        else
+                iovad->cached_node = &new->node;
 }
 
 static void
 __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
 {
         struct iova *cached_iova;
-        struct rb_node *curr;
 
-        if (!iovad->cached32_node)
-                return;
-        curr = iovad->cached32_node;
-        cached_iova = rb_entry(curr, struct iova, node);
+        cached_iova = rb_entry(iovad->cached32_node, struct iova, node);
+        if (free->pfn_hi < iovad->dma_32bit_pfn &&
+            iovad->cached32_node && free->pfn_lo >= cached_iova->pfn_lo)
+                iovad->cached32_node = rb_next(&free->node);
 
-        if (free->pfn_lo >= cached_iova->pfn_lo) {
-                struct rb_node *node = rb_next(&free->node);
-                struct iova *iova = rb_entry(node, struct iova, node);
-
-                /* only cache if it's below 32bit pfn */
-                if (node && iova->pfn_lo < iovad->dma_32bit_pfn)
-                        iovad->cached32_node = node;
-                else
-                        iovad->cached32_node = NULL;
-        }
+        cached_iova = rb_entry(iovad->cached_node, struct iova, node);
+        if (iovad->cached_node && free->pfn_lo >= cached_iova->pfn_lo)
+                iovad->cached_node = rb_next(&free->node);
 }
 
 /* Insert the iova into domain rbtree by holding writer lock */
@@ -188,7 +185,7 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
 {
         struct rb_node *prev, *curr = NULL;
         unsigned long flags;
-        unsigned long saved_pfn, new_pfn;
+        unsigned long new_pfn;
         unsigned long align_mask = ~0UL;
 
         if (size_aligned)
@@ -196,7 +193,6 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
 
         /* Walk the tree backwards */
         spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
-        saved_pfn = limit_pfn;
         curr = __get_cached_rbnode(iovad, &limit_pfn);
         prev = curr;
         while (curr) {
@@ -226,7 +222,7 @@ move_left:
 
         /* If we have 'prev', it's a valid place to start the insertion. */
         iova_insert_rbtree(&iovad->rbroot, new, prev);
-        __cached_rbnode_insert_update(iovad, saved_pfn, new);
+        __cached_rbnode_insert_update(iovad, new);
 
         spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
 
diff --git a/include/linux/iova.h b/include/linux/iova.h
index d179b9bf7814..69ea3e258ff2 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -70,7 +70,8 @@ struct iova_fq {
 struct iova_domain {
         spinlock_t      iova_rbtree_lock; /* Lock to protect update of rbtree */
         struct rb_root  rbroot;         /* iova domain rbtree root */
-        struct rb_node  *cached32_node; /* Save last alloced node */
+        struct rb_node  *cached_node;   /* Save last alloced node */
+        struct rb_node  *cached32_node; /* Save last 32-bit alloced node */
         unsigned long   granule;        /* pfn granularity for this domain */
         unsigned long   start_pfn;      /* Lower limit for this domain */
         unsigned long   dma_32bit_pfn;