xref: /linux-6.15/include/linux/delay.h (revision 4bedea94)
1 #ifndef _LINUX_DELAY_H
2 #define _LINUX_DELAY_H
3 
4 /*
5  * Copyright (C) 1993 Linus Torvalds
6  *
7  * Delay routines, using a pre-computed "loops_per_jiffy" value.
8  */
9 
10 extern unsigned long loops_per_jiffy;
11 
12 #include <asm/delay.h>
13 
14 /*
15  * Using udelay() for intervals greater than a few milliseconds can
16  * risk overflow for high loops_per_jiffy (high bogomips) machines. The
17  * mdelay() provides a wrapper to prevent this.  For delays greater
18  * than MAX_UDELAY_MS milliseconds, the wrapper is used.  Architecture
19  * specific values can be defined in asm-???/delay.h as an override.
20  * The 2nd mdelay() definition ensures GCC will optimize away the
21  * while loop for the common cases where n <= MAX_UDELAY_MS  --  Paul G.
22  */
23 
24 #ifndef MAX_UDELAY_MS
25 #define MAX_UDELAY_MS	5
26 #endif
27 
28 #ifdef notdef
29 #define mdelay(n) (\
30 	{unsigned long __ms=(n); while (__ms--) udelay(1000);})
31 #else
32 #define mdelay(n) (\
33 	(__builtin_constant_p(n) && (n)<=MAX_UDELAY_MS) ? udelay((n)*1000) : \
34 	({unsigned long __ms=(n); while (__ms--) udelay(1000);}))
35 #endif
36 
37 #ifndef ndelay
38 #define ndelay(x)	udelay(((x)+999)/1000)
39 #endif
40 
41 void calibrate_delay(void);
42 void msleep(unsigned int msecs);
43 unsigned long msleep_interruptible(unsigned int msecs);
44 
45 static inline void ssleep(unsigned int seconds)
46 {
47 	msleep(seconds * 1000);
48 }
49 
50 #endif /* defined(_LINUX_DELAY_H) */
51