Merge tag 'rpmsg-v4.14' of git://github.com/andersson/remoteproc

[sfrench/cifs-2.6.git] / lib / rbtree.c

diff --git a/lib/rbtree.c b/lib/rbtree.c
index 4ba2828a67c0401b371b04cce7c52d566b5c0e74..ba4a9d165f1bed3c39651387def0008fc793fbd6 100644 (file)
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -95,22 +95,35 @@ __rb_rotate_set_parents(struct rb_node *old, struct rb_node *new,
 
 static __always_inline void
 __rb_insert(struct rb_node *node, struct rb_root *root,
+           bool newleft, struct rb_node **leftmost,
            void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
 {
        struct rb_node *parent = rb_red_parent(node), *gparent, *tmp;
 
+       if (newleft)
+               *leftmost = node;
+
        while (true) {
                /*
-                * Loop invariant: node is red
-                *
-                * If there is a black parent, we are done.
-                * Otherwise, take some corrective action as we don't
-                * want a red root or two consecutive red nodes.
+                * Loop invariant: node is red.
                 */
-               if (!parent) {
+               if (unlikely(!parent)) {
+                       /*
+                        * The inserted node is root. Either this is the
+                        * first node, or we recursed at Case 1 below and
+                        * are no longer violating 4).
+                        */
                        rb_set_parent_color(node, NULL, RB_BLACK);
                        break;
-               } else if (rb_is_black(parent))
+               }
+
+               /*
+                * If there is a black parent, we are done.
+                * Otherwise, take some corrective action as,
+                * per 4), we don't want a red root or two
+                * consecutive red nodes.
+                */
+               if(rb_is_black(parent))
                        break;
 
                gparent = rb_red_parent(parent);
@@ -119,7 +132,7 @@ __rb_insert(struct rb_node *node, struct rb_root *root,
                if (parent != tmp) {    /* parent == gparent->rb_left */
                        if (tmp && rb_is_red(tmp)) {
                                /*
-                                * Case 1 - color flips
+                                * Case 1 - node's uncle is red (color flips).
                                 *
                                 *       G            g
                                 *      / \          / \
@@ -142,7 +155,8 @@ __rb_insert(struct rb_node *node, struct rb_root *root,
                        tmp = parent->rb_right;
                        if (node == tmp) {
                                /*
-                                * Case 2 - left rotate at parent
+                                * Case 2 - node's uncle is black and node is
+                                * the parent's right child (left rotate at parent).
                                 *
                                 *      G             G
                                 *     / \           / \
@@ -166,7 +180,8 @@ __rb_insert(struct rb_node *node, struct rb_root *root,
                        }
 
                        /*
-                        * Case 3 - right rotate at gparent
+                        * Case 3 - node's uncle is black and node is
+                        * the parent's left child (right rotate at gparent).
                         *
                         *        G           P
                         *       / \         / \
@@ -434,19 +449,38 @@ static const struct rb_augment_callbacks dummy_callbacks = {
 
 void rb_insert_color(struct rb_node *node, struct rb_root *root)
 {
-       __rb_insert(node, root, dummy_rotate);
+       __rb_insert(node, root, false, NULL, dummy_rotate);
 }
 EXPORT_SYMBOL(rb_insert_color);
 
 void rb_erase(struct rb_node *node, struct rb_root *root)
 {
        struct rb_node *rebalance;
-       rebalance = __rb_erase_augmented(node, root, &dummy_callbacks);
+       rebalance = __rb_erase_augmented(node, root,
+                                        NULL, &dummy_callbacks);
        if (rebalance)
                ____rb_erase_color(rebalance, root, dummy_rotate);
 }
 EXPORT_SYMBOL(rb_erase);
 
+void rb_insert_color_cached(struct rb_node *node,
+                           struct rb_root_cached *root, bool leftmost)
+{
+       __rb_insert(node, &root->rb_root, leftmost,
+                   &root->rb_leftmost, dummy_rotate);
+}
+EXPORT_SYMBOL(rb_insert_color_cached);
+
+void rb_erase_cached(struct rb_node *node, struct rb_root_cached *root)
+{
+       struct rb_node *rebalance;
+       rebalance = __rb_erase_augmented(node, &root->rb_root,
+                                        &root->rb_leftmost, &dummy_callbacks);
+       if (rebalance)
+               ____rb_erase_color(rebalance, &root->rb_root, dummy_rotate);
+}
+EXPORT_SYMBOL(rb_erase_cached);
+
 /*
  * Augmented rbtree manipulation functions.
  *
@@ -455,9 +489,10 @@ EXPORT_SYMBOL(rb_erase);
  */
 
 void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
+                          bool newleft, struct rb_node **leftmost,
        void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
 {
-       __rb_insert(node, root, augment_rotate);
+       __rb_insert(node, root, newleft, leftmost, augment_rotate);
 }
 EXPORT_SYMBOL(__rb_insert_augmented);
 
@@ -502,7 +537,7 @@ struct rb_node *rb_next(const struct rb_node *node)
         * as we can.
         */
        if (node->rb_right) {
-               node = node->rb_right; 
+               node = node->rb_right;
                while (node->rb_left)
                        node=node->rb_left;
                return (struct rb_node *)node;
@@ -534,7 +569,7 @@ struct rb_node *rb_prev(const struct rb_node *node)
         * as we can.
         */
        if (node->rb_left) {
-               node = node->rb_left; 
+               node = node->rb_left;
                while (node->rb_right)
                        node=node->rb_right;
                return (struct rb_node *)node;