xref: /linux/include/uapi/asm-generic/bitsperlong.h (revision 561add0da6d3d07c9bccb0832fb6ed5619167d26)
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