asm-generic: add generic NOMMU versions of some headers

Memory management in generic is highly architecture specific,
but on NOMMU architectures, it is mostly trivial, so just
add a default implementation in asm-generic that applies
to all NOMMU architectures.

The two files cache.h and cacheflush.h can possibly also
be used by architectures that have an MMU but never require
flushing the cache or have cache lines larger than 32 bytes.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
new file mode 100644
index 0000000..9e429d0
--- /dev/null
+++ b/include/asm-generic/pgalloc.h
@@ -0,0 +1,12 @@
+#ifndef __ASM_GENERIC_PGALLOC_H
+#define __ASM_GENERIC_PGALLOC_H
+/*
+ * an empty file is enough for a nommu architecture
+ */
+#ifdef CONFIG_MMU
+#error need to implement an architecture specific asm/pgalloc.h
+#endif
+
+#define check_pgt_cache()          do { } while (0)
+
+#endif /* __ASM_GENERIC_PGALLOC_H */