1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * Delay loops based on the OpenRISC implement
4 *
5 * Copyright (C) 2012 ARM Limited
6 *
7 * Author: Will Deacon <will.deacon@arm.com>
8 */
9
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/timex.h>
15
16 #include <clocksource/arm_arch_timer.h>
17
18 #define USECS_TO_CYCLES(time_usecs)
19 xloops_to_cycles((time_usecs) * 0x10C7
20
21 static inline unsigned long xloops_to_cycles(u
22 {
23 return (xloops * loops_per_jiffy * HZ)
24 }
25
26 void __delay(unsigned long cycles)
27 {
28 cycles_t start = get_cycles();
29
30 if (alternative_has_cap_unlikely(ARM64
31 u64 end = start + cycles;
32
33 /*
34 * Start with WFIT. If an inte
35 * early, use a WFET loop to c
36 */
37 wfit(end);
38 while ((get_cycles() - start)
39 wfet(end);
40 } else if (arch_timer_evtstrm_availab
41 const cycles_t timer_evt_perio
42 USECS_TO_CYCLES(ARCH_T
43
44 while ((get_cycles() - start +
45 wfe();
46 }
47
48 while ((get_cycles() - start) < cycles
49 cpu_relax();
50 }
51 EXPORT_SYMBOL(__delay);
52
53 inline void __const_udelay(unsigned long xloop
54 {
55 __delay(xloops_to_cycles(xloops));
56 }
57 EXPORT_SYMBOL(__const_udelay);
58
59 void __udelay(unsigned long usecs)
60 {
61 __const_udelay(usecs * 0x10C7UL); /* 2
62 }
63 EXPORT_SYMBOL(__udelay);
64
65 void __ndelay(unsigned long nsecs)
66 {
67 __const_udelay(nsecs * 0x5UL); /* 2**3
68 }
69 EXPORT_SYMBOL(__ndelay);
70
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