xref: /openbmc/linux/arch/x86/include/asm/delay.h (revision 1fa6ac37)
1 #ifndef _ASM_X86_DELAY_H
2 #define _ASM_X86_DELAY_H
3 
4 /*
5  * Copyright (C) 1993 Linus Torvalds
6  *
7  * Delay routines calling functions in arch/x86/lib/delay.c
8  */
9 
10 /* Undefined functions to get compile-time errors */
11 extern void __bad_udelay(void);
12 extern void __bad_ndelay(void);
13 
14 extern void __udelay(unsigned long usecs);
15 extern void __ndelay(unsigned long nsecs);
16 extern void __const_udelay(unsigned long xloops);
17 extern void __delay(unsigned long loops);
18 
19 /* 0x10c7 is 2**32 / 1000000 (rounded up) */
20 #define udelay(n) (__builtin_constant_p(n) ? \
21 	((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
22 	__udelay(n))
23 
24 /* 0x5 is 2**32 / 1000000000 (rounded up) */
25 #define ndelay(n) (__builtin_constant_p(n) ? \
26 	((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \
27 	__ndelay(n))
28 
29 void use_tsc_delay(void);
30 
31 #endif /* _ASM_X86_DELAY_H */
32