projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 | ||
| 11 | #include <linux/config.h> | |
| 12 | #include <linux/sched.h> | |
| 13 | #include <linux/delay.h> | |
| 14 | #include <asm/delay.h> | |
| 8a9e1b0f | 15 | #include <asm/msr.h> |
| 1da177e4 LT |
16 | |
| 17 | #ifdef CONFIG_SMP | |
| 18 | #include <asm/smp.h> | |
| 19 | #endif | |
| 20 | ||
| 8a9e1b0f VP |
21 | int read_current_timer(unsigned long *timer_value) |
| 22 | { | |
| 23 | rdtscll(*timer_value); | |
| 24 | return 0; | |
| 25 | } | |
| 26 | ||
| 1da177e4 LT |
27 | void __delay(unsigned long loops) |
| 28 | { | |
| 29 | unsigned bclock, now; | |
| 30 | ||
| 31 | rdtscl(bclock); | |
| 32 | do | |
| 33 | { | |
| 34 | rep_nop(); | |
| 35 | rdtscl(now); | |
| 36 | } | |
| 37 | while((now-bclock) < loops); | |
| 38 | } | |
| 39 | ||
| 40 | inline void __const_udelay(unsigned long xloops) | |
| 41 | { | |
| 39c715b7 | 42 | __delay(((xloops * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32) * HZ); |
| 1da177e4 LT |
43 | } |
| 44 | ||
| 45 | void __udelay(unsigned long usecs) | |
| 46 | { | |
| 47 | __const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */ | |
| 48 | } | |
| 49 | ||
| 50 | void __ndelay(unsigned long nsecs) | |
| 51 | { | |
| 52 | __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ | |
| 53 | } |