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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Precise Delay Loops for x86-64 | |
3 | * | |
4 | * Copyright (C) 1993 Linus Torvalds | |
5 | * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> | |
6 | * | |
7 | * The __delay function must _NOT_ be inlined as its execution time | |
8 | * depends wildly on alignment on many x86 processors. | |
9 | */ | |
10 | ||
2ee60e17 | 11 | #include <linux/module.h> |
1da177e4 | 12 | #include <linux/sched.h> |
941e492b | 13 | #include <linux/timex.h> |
35d5d08a | 14 | #include <linux/preempt.h> |
1da177e4 | 15 | #include <linux/delay.h> |
941e492b | 16 | #include <linux/init.h> |
35d5d08a | 17 | |
1da177e4 | 18 | #include <asm/delay.h> |
8a9e1b0f | 19 | #include <asm/msr.h> |
1da177e4 LT |
20 | |
21 | #ifdef CONFIG_SMP | |
22 | #include <asm/smp.h> | |
23 | #endif | |
24 | ||
941e492b | 25 | int __devinit read_current_timer(unsigned long *timer_value) |
8a9e1b0f VP |
26 | { |
27 | rdtscll(*timer_value); | |
28 | return 0; | |
29 | } | |
30 | ||
1da177e4 LT |
31 | void __delay(unsigned long loops) |
32 | { | |
33 | unsigned bclock, now; | |
35d5d08a AM |
34 | |
35 | preempt_disable(); /* TSC's are pre-cpu */ | |
1da177e4 | 36 | rdtscl(bclock); |
35d5d08a | 37 | do { |
1da177e4 LT |
38 | rep_nop(); |
39 | rdtscl(now); | |
40 | } | |
35d5d08a AM |
41 | while ((now-bclock) < loops); |
42 | preempt_enable(); | |
1da177e4 | 43 | } |
2ee60e17 | 44 | EXPORT_SYMBOL(__delay); |
1da177e4 LT |
45 | |
46 | inline void __const_udelay(unsigned long xloops) | |
47 | { | |
92cb7612 MT |
48 | __delay(((xloops * HZ * |
49 | cpu_data(raw_smp_processor_id()).loops_per_jiffy) >> 32) + 1); | |
1da177e4 | 50 | } |
2ee60e17 | 51 | EXPORT_SYMBOL(__const_udelay); |
1da177e4 LT |
52 | |
53 | void __udelay(unsigned long usecs) | |
54 | { | |
b9a8d94a | 55 | __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ |
1da177e4 | 56 | } |
2ee60e17 | 57 | EXPORT_SYMBOL(__udelay); |
1da177e4 LT |
58 | |
59 | void __ndelay(unsigned long nsecs) | |
60 | { | |
61 | __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ | |
62 | } | |
2ee60e17 | 63 | EXPORT_SYMBOL(__ndelay); |