+/**
+ * init_seen - allocate memory for used for debugging.
+ * @ubi: UBI device description object
+ */
+static inline int *init_seen(struct ubi_device *ubi)
+{
+ int *ret;
+
+ if (!ubi_dbg_chk_fastmap(ubi))
+ return NULL;
+
+ ret = kcalloc(ubi->peb_count, sizeof(int), GFP_KERNEL);
+ if (!ret)
+ return ERR_PTR(-ENOMEM);
+
+ return ret;
+}
+
+/**
+ * free_seen - free the seen logic integer array.
+ * @seen: integer array of @ubi->peb_count size
+ */
+static inline void free_seen(int *seen)
+{
+ kfree(seen);
+}
+
+/**
+ * set_seen - mark a PEB as seen.
+ * @ubi: UBI device description object
+ * @pnum: The PEB to be makred as seen
+ * @seen: integer array of @ubi->peb_count size
+ */
+static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)
+{
+ if (!ubi_dbg_chk_fastmap(ubi) || !seen)
+ return;
+
+ seen[pnum] = 1;
+}
+
+/**
+ * self_check_seen - check whether all PEB have been seen by fastmap.
+ * @ubi: UBI device description object
+ * @seen: integer array of @ubi->peb_count size
+ */
+static int self_check_seen(struct ubi_device *ubi, int *seen)
+{
+ int pnum, ret = 0;
+
+ if (!ubi_dbg_chk_fastmap(ubi) || !seen)
+ return 0;
+
+ for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+ if (!seen[pnum] && ubi->lookuptbl[pnum]) {
+ ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
+ ret = -EINVAL;
+ }
+ }
+
+ return ret;
+}
+