asm-generic: introduce asm/bitsperlong.h

This provides a reliable way for asm-generic/types.h and other
files to find out if it is running on a 32 or 64 bit platform.

We cannot use CONFIG_64BIT for this in headers that are included
from user space because CONFIG symbols are not available there.
We also cannot do it inside of asm/types.h because some headers
need the word size but cannot include types.h.

The solution is to introduce a new header <asm/bitsperlong.h>
that defines both __BITS_PER_LONG for user space and
BITS_PER_LONG for usage in the kernel. The asm-generic
version falls back to 32 bit unless the architecture overrides
it, which I did for all 64 bit platforms.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 8 insertions, 3 deletions

diff --git a/arch/alpha/include/asm/bitsperlong.h b/arch/alpha/include/asm/bitsperlong.h
new file mode 100644
index 0000000..ad57f78
--- /dev/null
+++ b/arch/alpha/include/asm/bitsperlong.h
@@ -0,0 +1,8 @@
+#ifndef __ASM_ALPHA_BITSPERLONG_H
+#define __ASM_ALPHA_BITSPERLONG_H
+
+#define __BITS_PER_LONG 64
+
+#include <asm-generic/bitsperlong.h>
+
+#endif /* __ASM_ALPHA_BITSPERLONG_H */
diff --git a/arch/alpha/include/asm/types.h b/arch/alpha/include/asm/types.h
index f072f34..bd621ec 100644
--- a/arch/alpha/include/asm/types.h
+++ b/arch/alpha/include/asm/types.h
@@ -25,9 +25,6 @@ typedef unsigned int umode_t;
  * These aren't exported outside the kernel to avoid name space clashes
  */
 #ifdef __KERNEL__
-
-#define BITS_PER_LONG 64
-
 #ifndef __ASSEMBLY__
 
 typedef u64 dma_addr_t;