linux/include/asm-generic/bitsperlong.h
Arnd Bergmann c31ae4bb4a 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>
2009-06-11 21:02:14 +02:00

32 lines
874 B
C

#ifndef __ASM_GENERIC_BITS_PER_LONG
#define __ASM_GENERIC_BITS_PER_LONG
/*
* There seems to be no way of detecting this automatically from user
* space, so 64 bit architectures should override this in their
* bitsperlong.h. In particular, an architecture that supports
* both 32 and 64 bit user space must not rely on CONFIG_64BIT
* to decide it, but rather check a compiler provided macro.
*/
#ifndef __BITS_PER_LONG
#define __BITS_PER_LONG 32
#endif
#ifdef __KERNEL__
#ifdef CONFIG_64BIT
#define BITS_PER_LONG 64
#else
#define BITS_PER_LONG 32
#endif /* CONFIG_64BIT */
/*
* FIXME: The check currently breaks x86-64 build, so it's
* temporarily disabled. Please fix x86-64 and reenable
*/
#if 0 && BITS_PER_LONG != __BITS_PER_LONG
#error Inconsistent word size. Check asm/bitsperlong.h
#endif
#endif /* __KERNEL__ */
#endif /* __ASM_GENERIC_BITS_PER_LONG */