xref: /linux/include/asm-generic/bitsperlong.h (revision dc432ab7130bb39f5a351281a02d4bc61e85a14a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_GENERIC_BITS_PER_LONG
3 #define __ASM_GENERIC_BITS_PER_LONG
4 
5 #include <uapi/asm-generic/bitsperlong.h>
6 
7 
8 #ifdef CONFIG_64BIT
9 #define BITS_PER_LONG 64
10 #else
11 #define BITS_PER_LONG 32
12 #endif /* CONFIG_64BIT */
13 
14 /*
15  * FIXME: The check currently breaks x86-64 build, so it's
16  * temporarily disabled. Please fix x86-64 and reenable
17  */
18 #if 0 && BITS_PER_LONG != __BITS_PER_LONG
19 #error Inconsistent word size. Check asm/bitsperlong.h
20 #endif
21 
22 #if __CHAR_BIT__ * __SIZEOF_LONG__ != __BITS_PER_LONG
23 #error Inconsistent word size. Check asm/bitsperlong.h
24 #endif
25 
26 #ifndef __ASSEMBLER__
27 _Static_assert(sizeof(long) * 8 == __BITS_PER_LONG,
28 	       "Inconsistent word size. Check asm/bitsperlong.h");
29 #endif
30 
31 #ifndef BITS_PER_LONG_LONG
32 #define BITS_PER_LONG_LONG 64
33 #endif
34 
35 /*
36  * small_const_nbits(n) is true precisely when it is known at compile-time
37  * that BITMAP_SIZE(n) is 1, i.e. 1 <= n <= BITS_PER_LONG. This allows
38  * various bit/bitmap APIs to provide a fast inline implementation. Bitmaps
39  * of size 0 are very rare, and a compile-time-known-size 0 is most likely
40  * a sign of error. They will be handled correctly by the bit/bitmap APIs,
41  * but using the out-of-line functions, so that the inline implementations
42  * can unconditionally dereference the pointer(s).
43  */
44 #define small_const_nbits(nbits) \
45 	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
46 
47 #endif /* __ASM_GENERIC_BITS_PER_LONG */
48