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c55377ee PM |
1 | #ifndef _ASM_POWERPC_DELAY_H |
2 | #define _ASM_POWERPC_DELAY_H | |
88ced031 | 3 | #ifdef __KERNEL__ |
1da177e4 | 4 | |
9317726d TT |
5 | #include <asm/time.h> |
6 | ||
1da177e4 LT |
7 | /* |
8 | * Copyright 1996, Paul Mackerras. | |
9317726d | 9 | * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved. |
1da177e4 LT |
10 | * |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | * | |
16 | * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan, | |
17 | * Anton Blanchard. | |
18 | */ | |
19 | ||
6defa38b PM |
20 | extern void __delay(unsigned long loops); |
21 | extern void udelay(unsigned long usecs); | |
1da177e4 | 22 | |
1e92a550 AB |
23 | /* |
24 | * On shared processor machines the generic implementation of mdelay can | |
25 | * result in large errors. While each iteration of the loop inside mdelay | |
26 | * is supposed to take 1ms, the hypervisor could sleep our partition for | |
27 | * longer (eg 10ms). With the right timing these errors can add up. | |
28 | * | |
29 | * Since there is no 32bit overflow issue on 64bit kernels, just call | |
30 | * udelay directly. | |
31 | */ | |
32 | #ifdef CONFIG_PPC64 | |
33 | #define mdelay(n) udelay((n) * 1000) | |
34 | #endif | |
35 | ||
9317726d TT |
36 | /** |
37 | * spin_event_timeout - spin until a condition gets true or a timeout elapses | |
38 | * @condition: a C expression to evalate | |
39 | * @timeout: timeout, in microseconds | |
40 | * @delay: the number of microseconds to delay between each evaluation of | |
41 | * @condition | |
42 | * | |
43 | * The process spins until the condition evaluates to true (non-zero) or the | |
44 | * timeout elapses. The return value of this macro is the value of | |
45 | * @condition when the loop terminates. This allows you to determine the cause | |
46 | * of the loop terminates. If the return value is zero, then you know a | |
47 | * timeout has occurred. | |
48 | * | |
49 | * This primary purpose of this macro is to poll on a hardware register | |
50 | * until a status bit changes. The timeout ensures that the loop still | |
51 | * terminates even if the bit never changes. The delay is for devices that | |
52 | * need a delay in between successive reads. | |
53 | * | |
54 | * gcc will optimize out the if-statement if @delay is a constant. | |
55 | */ | |
56 | #define spin_event_timeout(condition, timeout, delay) \ | |
57 | ({ \ | |
58 | typeof(condition) __ret; \ | |
59 | unsigned long __loops = tb_ticks_per_usec * timeout; \ | |
60 | unsigned long __start = get_tbl(); \ | |
61 | while (!(__ret = (condition)) && (tb_ticks_since(__start) <= __loops)) \ | |
62 | if (delay) \ | |
63 | udelay(delay); \ | |
64 | else \ | |
65 | cpu_relax(); \ | |
ad9064d5 GL |
66 | if (!__ret) \ |
67 | __ret = (condition); \ | |
9317726d TT |
68 | __ret; \ |
69 | }) | |
70 | ||
88ced031 | 71 | #endif /* __KERNEL__ */ |
c55377ee | 72 | #endif /* _ASM_POWERPC_DELAY_H */ |