Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Precise Delay Loops for S390 |
4 | * | |
a53c8fab | 5 | * Copyright IBM Corp. 1999, 2008 |
d3d238c7 | 6 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, |
1da177e4 LT |
7 | */ |
8 | ||
3da77cf3 | 9 | #include <linux/processor.h> |
1da177e4 | 10 | #include <linux/delay.h> |
b3966378 | 11 | #include <asm/div64.h> |
3da77cf3 | 12 | #include <asm/timex.h> |
1da177e4 LT |
13 | |
14 | void __delay(unsigned long loops) | |
15 | { | |
9aa10e79 HC |
16 | /* |
17 | * Loop 'loops' times. Callers must not assume a specific | |
18 | * amount of time passes before this function returns. | |
19 | */ | |
94c12cc7 | 20 | asm volatile("0: brct %0,0b" : : "d" ((loops/2) + 1)); |
1da177e4 | 21 | } |
854508c0 | 22 | EXPORT_SYMBOL(__delay); |
1da177e4 | 23 | |
e0d62dcb | 24 | static void delay_loop(unsigned long delta) |
1da177e4 | 25 | { |
dd6cfe55 | 26 | unsigned long end; |
d54853ef | 27 | |
e0d62dcb HC |
28 | end = get_tod_clock_monotonic() + delta; |
29 | while (!tod_after(get_tod_clock_monotonic(), end)) | |
30 | cpu_relax(); | |
d3d238c7 | 31 | } |
d54853ef | 32 | |
dd6cfe55 | 33 | void __udelay(unsigned long usecs) |
d3d238c7 | 34 | { |
e0d62dcb | 35 | delay_loop(usecs << 12); |
1da177e4 | 36 | } |
1485c5c8 | 37 | EXPORT_SYMBOL(__udelay); |
5a0d0e65 | 38 | |
dd6cfe55 | 39 | void __ndelay(unsigned long nsecs) |
b3966378 | 40 | { |
b3966378 HC |
41 | nsecs <<= 9; |
42 | do_div(nsecs, 125); | |
e0d62dcb | 43 | delay_loop(nsecs); |
b3966378 HC |
44 | } |
45 | EXPORT_SYMBOL(__ndelay); |