+/*
+ * Macros for declaration and initialization of the kfifo datatype
+ */
+
+/* helper macro */
+#define __kfifo_initializer(s, b) \
+ (struct kfifo) { \
+ .size = s, \
+ .in = 0, \
+ .out = 0, \
+ .buffer = b \
+ }
+
+/**
+ * DECLARE_KFIFO - macro to declare a kfifo and the associated buffer
+ * @name: name of the declared kfifo datatype
+ * @size: size of the fifo buffer
+ *
+ * Note: the macro can be used inside struct or union declaration
+ * Note: the macro creates two objects:
+ * A kfifo object with the given name and a buffer for the kfifo
+ * object named name##kfifo_buffer
+ */
+#define DECLARE_KFIFO(name, size) \
+union { \
+ struct kfifo name; \
+ unsigned char name##kfifo_buffer[size + sizeof(struct kfifo)]; \
+}
+
+/**
+ * INIT_KFIFO - Initialize a kfifo declared by DECLARED_KFIFO
+ * @name: name of the declared kfifo datatype
+ * @size: size of the fifo buffer
+ */
+#define INIT_KFIFO(name) \
+ name = __kfifo_initializer(sizeof(name##kfifo_buffer) - \
+ sizeof(struct kfifo), name##kfifo_buffer)
+
+/**
+ * DEFINE_KFIFO - macro to define and initialize a kfifo
+ * @name: name of the declared kfifo datatype
+ * @size: size of the fifo buffer
+ *
+ * Note: the macro can be used for global and local kfifo data type variables
+ * Note: the macro creates two objects:
+ * A kfifo object with the given name and a buffer for the kfifo
+ * object named name##kfifo_buffer
+ */
+#define DEFINE_KFIFO(name, size) \
+ unsigned char name##kfifo_buffer[size]; \
+ struct kfifo name = __kfifo_initializer(size, name##kfifo_buffer)
+
+#undef __kfifo_initializer
+