[PATCH RFC 2/4] asm-generic/io.h: Add IO_SPACE_BASE

[John Garry]

Add a fallback default for IO_SPACE_BASE (at 0) for when an architecture
does not define a value.

Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 include/asm-generic/io.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 9ea83d80eb6f..4d74a0c696ca 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -448,6 +448,10 @@ static inline void writesq(volatile void __iomem *addr, const void *buffer,
 #define IO_SPACE_LIMIT 0xffff
 #endif
 
+#ifndef IO_SPACE_BASE
+#define IO_SPACE_BASE 0x0
+#endif
+
 /*
  * {in,out}{b,w,l}() access little endian I/O. {in,out}{b,w,l}_p() can be
  * implemented on hardware that needs an additional delay for I/O accesses to
-- 
2.26.2