ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/fs/btrfs/ulist.c b/marvell/linux/fs/btrfs/ulist.c
new file mode 100644
index 0000000..3374c9e
--- /dev/null
+++ b/marvell/linux/fs/btrfs/ulist.c
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2011 STRATO AG
+ * written by Arne Jansen <sensille@gmx.net>
+ */
+
+#include <linux/slab.h>
+#include "ulist.h"
+#include "ctree.h"
+
+/*
+ * ulist is a generic data structure to hold a collection of unique u64
+ * values. The only operations it supports is adding to the list and
+ * enumerating it.
+ * It is possible to store an auxiliary value along with the key.
+ *
+ * A sample usage for ulists is the enumeration of directed graphs without
+ * visiting a node twice. The pseudo-code could look like this:
+ *
+ * ulist = ulist_alloc();
+ * ulist_add(ulist, root);
+ * ULIST_ITER_INIT(&uiter);
+ *
+ * while ((elem = ulist_next(ulist, &uiter)) {
+ * for (all child nodes n in elem)
+ * ulist_add(ulist, n);
+ * do something useful with the node;
+ * }
+ * ulist_free(ulist);
+ *
+ * This assumes the graph nodes are addressable by u64. This stems from the
+ * usage for tree enumeration in btrfs, where the logical addresses are
+ * 64 bit.
+ *
+ * It is also useful for tree enumeration which could be done elegantly
+ * recursively, but is not possible due to kernel stack limitations. The
+ * loop would be similar to the above.
+ */
+
+/**
+ * ulist_init - freshly initialize a ulist
+ * @ulist: the ulist to initialize
+ *
+ * Note: don't use this function to init an already used ulist, use
+ * ulist_reinit instead.
+ */
+void ulist_init(struct ulist *ulist)
+{
+ INIT_LIST_HEAD(&ulist->nodes);
+ ulist->root = RB_ROOT;
+ ulist->nnodes = 0;
+}
+
+/**
+ * ulist_release - free up additionally allocated memory for the ulist
+ * @ulist: the ulist from which to free the additional memory
+ *
+ * This is useful in cases where the base 'struct ulist' has been statically
+ * allocated.
+ */
+void ulist_release(struct ulist *ulist)
+{
+ struct ulist_node *node;
+ struct ulist_node *next;
+
+ list_for_each_entry_safe(node, next, &ulist->nodes, list) {
+ kfree(node);
+ }
+ ulist->root = RB_ROOT;
+ INIT_LIST_HEAD(&ulist->nodes);
+}
+
+/**
+ * ulist_reinit - prepare a ulist for reuse
+ * @ulist: ulist to be reused
+ *
+ * Free up all additional memory allocated for the list elements and reinit
+ * the ulist.
+ */
+void ulist_reinit(struct ulist *ulist)
+{
+ ulist_release(ulist);
+ ulist_init(ulist);
+}
+
+/**
+ * ulist_alloc - dynamically allocate a ulist
+ * @gfp_mask: allocation flags to for base allocation
+ *
+ * The allocated ulist will be returned in an initialized state.
+ */
+struct ulist *ulist_alloc(gfp_t gfp_mask)
+{
+ struct ulist *ulist = kmalloc(sizeof(*ulist), gfp_mask);
+
+ if (!ulist)
+ return NULL;
+
+ ulist_init(ulist);
+
+ return ulist;
+}
+
+/**
+ * ulist_free - free dynamically allocated ulist
+ * @ulist: ulist to free
+ *
+ * It is not necessary to call ulist_release before.
+ */
+void ulist_free(struct ulist *ulist)
+{
+ if (!ulist)
+ return;
+ ulist_release(ulist);
+ kfree(ulist);
+}
+
+static struct ulist_node *ulist_rbtree_search(struct ulist *ulist, u64 val)
+{
+ struct rb_node *n = ulist->root.rb_node;
+ struct ulist_node *u = NULL;
+
+ while (n) {
+ u = rb_entry(n, struct ulist_node, rb_node);
+ if (u->val < val)
+ n = n->rb_right;
+ else if (u->val > val)
+ n = n->rb_left;
+ else
+ return u;
+ }
+ return NULL;
+}
+
+static void ulist_rbtree_erase(struct ulist *ulist, struct ulist_node *node)
+{
+ rb_erase(&node->rb_node, &ulist->root);
+ list_del(&node->list);
+ kfree(node);
+ BUG_ON(ulist->nnodes == 0);
+ ulist->nnodes--;
+}
+
+static int ulist_rbtree_insert(struct ulist *ulist, struct ulist_node *ins)
+{
+ struct rb_node **p = &ulist->root.rb_node;
+ struct rb_node *parent = NULL;
+ struct ulist_node *cur = NULL;
+
+ while (*p) {
+ parent = *p;
+ cur = rb_entry(parent, struct ulist_node, rb_node);
+
+ if (cur->val < ins->val)
+ p = &(*p)->rb_right;
+ else if (cur->val > ins->val)
+ p = &(*p)->rb_left;
+ else
+ return -EEXIST;
+ }
+ rb_link_node(&ins->rb_node, parent, p);
+ rb_insert_color(&ins->rb_node, &ulist->root);
+ return 0;
+}
+
+/**
+ * ulist_add - add an element to the ulist
+ * @ulist: ulist to add the element to
+ * @val: value to add to ulist
+ * @aux: auxiliary value to store along with val
+ * @gfp_mask: flags to use for allocation
+ *
+ * Note: locking must be provided by the caller. In case of rwlocks write
+ * locking is needed
+ *
+ * Add an element to a ulist. The @val will only be added if it doesn't
+ * already exist. If it is added, the auxiliary value @aux is stored along with
+ * it. In case @val already exists in the ulist, @aux is ignored, even if
+ * it differs from the already stored value.
+ *
+ * ulist_add returns 0 if @val already exists in ulist and 1 if @val has been
+ * inserted.
+ * In case of allocation failure -ENOMEM is returned and the ulist stays
+ * unaltered.
+ */
+int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask)
+{
+ return ulist_add_merge(ulist, val, aux, NULL, gfp_mask);
+}
+
+int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
+ u64 *old_aux, gfp_t gfp_mask)
+{
+ int ret;
+ struct ulist_node *node;
+
+ node = ulist_rbtree_search(ulist, val);
+ if (node) {
+ if (old_aux)
+ *old_aux = node->aux;
+ return 0;
+ }
+ node = kmalloc(sizeof(*node), gfp_mask);
+ if (!node)
+ return -ENOMEM;
+
+ node->val = val;
+ node->aux = aux;
+
+ ret = ulist_rbtree_insert(ulist, node);
+ ASSERT(!ret);
+ list_add_tail(&node->list, &ulist->nodes);
+ ulist->nnodes++;
+
+ return 1;
+}
+
+/*
+ * ulist_del - delete one node from ulist
+ * @ulist: ulist to remove node from
+ * @val: value to delete
+ * @aux: aux to delete
+ *
+ * The deletion will only be done when *BOTH* val and aux matches.
+ * Return 0 for successful delete.
+ * Return > 0 for not found.
+ */
+int ulist_del(struct ulist *ulist, u64 val, u64 aux)
+{
+ struct ulist_node *node;
+
+ node = ulist_rbtree_search(ulist, val);
+ /* Not found */
+ if (!node)
+ return 1;
+
+ if (node->aux != aux)
+ return 1;
+
+ /* Found and delete */
+ ulist_rbtree_erase(ulist, node);
+ return 0;
+}
+
+/**
+ * ulist_next - iterate ulist
+ * @ulist: ulist to iterate
+ * @uiter: iterator variable, initialized with ULIST_ITER_INIT(&iterator)
+ *
+ * Note: locking must be provided by the caller. In case of rwlocks only read
+ * locking is needed
+ *
+ * This function is used to iterate an ulist.
+ * It returns the next element from the ulist or %NULL when the
+ * end is reached. No guarantee is made with respect to the order in which
+ * the elements are returned. They might neither be returned in order of
+ * addition nor in ascending order.
+ * It is allowed to call ulist_add during an enumeration. Newly added items
+ * are guaranteed to show up in the running enumeration.
+ */
+struct ulist_node *ulist_next(struct ulist *ulist, struct ulist_iterator *uiter)
+{
+ struct ulist_node *node;
+
+ if (list_empty(&ulist->nodes))
+ return NULL;
+ if (uiter->cur_list && uiter->cur_list->next == &ulist->nodes)
+ return NULL;
+ if (uiter->cur_list) {
+ uiter->cur_list = uiter->cur_list->next;
+ } else {
+ uiter->cur_list = ulist->nodes.next;
+ }
+ node = list_entry(uiter->cur_list, struct ulist_node, list);
+ return node;
+}