1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2#ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG
3#define _UAPI__ASM_GENERIC_BITS_PER_LONG
4
5#ifndef __BITS_PER_LONG
6/*
7 * In order to keep safe and avoid regression, only unify uapi
8 * bitsperlong.h for some archs which are using newer toolchains
9 * that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.
10 * See the following link for more info:
11 * https://lore.kernel.org/linux-arch/b9624545-2c80-49a1-ac3c-39264a591f7b@app.fastmail.com/
12 */
13#if defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__)
14#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
15#else
16/*
17 * There seems to be no way of detecting this automatically from user
18 * space, so 64 bit architectures should override this in their
19 * bitsperlong.h. In particular, an architecture that supports
20 * both 32 and 64 bit user space must not rely on CONFIG_64BIT
21 * to decide it, but rather check a compiler provided macro.
22 */
23#define __BITS_PER_LONG 32
24#endif
25#endif
26
27#endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */
28

source code of linux/include/uapi/asm-generic/bitsperlong.h