xref: /openbmc/linux/arch/parisc/include/asm/delay.h (revision 95e9fd10)
1 #ifndef _PARISC_DELAY_H
2 #define _PARISC_DELAY_H
3 
4 #include <asm/special_insns.h>    /* for mfctl() */
5 #include <asm/processor.h> /* for boot_cpu_data */
6 
7 
8 /*
9  * Copyright (C) 1993 Linus Torvalds
10  *
11  * Delay routines
12  */
13 
14 static __inline__ void __delay(unsigned long loops) {
15 	asm volatile(
16 	"	.balignl	64,0x34000034\n"
17 	"	addib,UV -1,%0,.\n"
18 	"	nop\n"
19 		: "=r" (loops) : "0" (loops));
20 }
21 
22 static __inline__ void __cr16_delay(unsigned long clocks) {
23 	unsigned long start;
24 
25 	/*
26 	 * Note: Due to unsigned math, cr16 rollovers shouldn't be
27 	 * a problem here. However, on 32 bit, we need to make sure
28 	 * we don't pass in too big a value. The current default
29 	 * value of MAX_UDELAY_MS should help prevent this.
30 	 */
31 
32 	start = mfctl(16);
33 	while ((mfctl(16) - start) < clocks)
34 	    ;
35 }
36 
37 static __inline__ void __udelay(unsigned long usecs) {
38 	__cr16_delay(usecs * ((unsigned long)boot_cpu_data.cpu_hz / 1000000UL));
39 }
40 
41 #define udelay(n) __udelay(n)
42 
43 #endif /* defined(_PARISC_DELAY_H) */
44