diff options
author | Arnd Bergmann <arnd@arndb.de> | 2009-05-13 22:56:25 +0000 |
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committer | Arnd Bergmann <arnd@klappe2.(none)> | 2009-06-11 21:02:14 +0200 |
commit | c31ae4bb4a9fa4606a74c0a4fb61b74f804e861e (patch) | |
tree | 7694b1a05bc1ac660ac26eb9997200556ccd3933 /include/asm-generic/bitsperlong.h | |
parent | 63b852a6b67d0820d388b0ecd0da83ccb4048b8d (diff) |
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>
Diffstat (limited to 'include/asm-generic/bitsperlong.h')
-rw-r--r-- | include/asm-generic/bitsperlong.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/asm-generic/bitsperlong.h b/include/asm-generic/bitsperlong.h new file mode 100644 index 00000000000..4ae54e07de8 --- /dev/null +++ b/include/asm-generic/bitsperlong.h @@ -0,0 +1,32 @@ +#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 */ |