flex_array: add flex_array_clear function

[karo-tx-linux.git] / lib / flex_array.c

diff --git a/lib/flex_array.c b/lib/flex_array.c
index 7baed2fc3bc82920f97183c6fa70532250d165b4..b68f99be4080283ab6c0b1e0c5d630330640cbb4 100644 (file)
--- a/lib/flex_array.c
+++ b/lib/flex_array.c
@@ -206,6 +206,32 @@ int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src,
        return 0;
 }
 
+/**
+ * flex_array_clear - clear element in array at @element_nr
+ * @element_nr:        index of the position to clear.
+ *
+ * Locking must be provided by the caller.
+ */
+int flex_array_clear(struct flex_array *fa, unsigned int element_nr)
+{
+       int part_nr = fa_element_to_part_nr(fa, element_nr);
+       struct flex_array_part *part;
+       void *dst;
+
+       if (element_nr >= fa->total_nr_elements)
+               return -ENOSPC;
+       if (elements_fit_in_base(fa))
+               part = (struct flex_array_part *)&fa->parts[0];
+       else {
+               part = fa->parts[part_nr];
+               if (!part)
+                       return -EINVAL;
+       }
+       dst = &part->elements[index_inside_part(fa, element_nr)];
+       memset(dst, 0, fa->element_size);
+       return 0;
+}
+
 /**
  * flex_array_prealloc - guarantee that array space exists
  * @start:     index of first array element for which space is allocated