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| 2 | #ifndef _ASM_POWERPC_DELAY_H
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| 3 | #define _ASM_POWERPC_DELAY_H
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| 4 | #ifdef __KERNEL__
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| 5 |
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| 6 | #include <linux/processor.h>
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| 7 | #include <asm/time.h>
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| 8 |
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| 9 | |
| 10 | * Copyright 1996, Paul Mackerras.
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| 11 | * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved.
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| 12 | *
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| 13 | * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
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| 14 | * Anton Blanchard.
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| 15 |
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| 16 |
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| 17 | extern void __delay(unsigned long loops);
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| 18 | extern void udelay(unsigned long usecs);
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| 19 |
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| 20 | |
| 21 | * On shared processor machines the generic implementation of mdelay can
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| 22 | * result in large errors. While each iteration of the loop inside mdelay
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| 23 | * is supposed to take 1ms, the hypervisor could sleep our partition for
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| 24 | * longer (eg 10ms). With the right timing these errors can add up.
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| 25 | *
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| 26 | * Since there is no 32bit overflow issue on 64bit kernels, just call
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| 27 | * udelay directly.
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| 28 |
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| 29 | #ifdef CONFIG_PPC64
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| 30 | #define mdelay(n) udelay((n) * 1000)
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| 31 | #endif
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| 32 |
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| 33 | |
| 34 | * spin_event_timeout - spin until a condition gets true or a timeout elapses
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| 35 | * @condition: a C expression to evalate
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| 36 | * @timeout: timeout, in microseconds
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| 37 | * @delay: the number of microseconds to delay between each evaluation of
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| 38 | * @condition
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| 39 | *
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| 40 | * The process spins until the condition evaluates to true (non-zero) or the
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| 41 | * timeout elapses. The return value of this macro is the value of
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| 42 | * @condition when the loop terminates. This allows you to determine the cause
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| 43 | * of the loop terminates. If the return value is zero, then you know a
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| 44 | * timeout has occurred.
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| 45 | *
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| 46 | * This primary purpose of this macro is to poll on a hardware register
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| 47 | * until a status bit changes. The timeout ensures that the loop still
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| 48 | * terminates even if the bit never changes. The delay is for devices that
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| 49 | * need a delay in between successive reads.
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| 50 | *
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| 51 | * gcc will optimize out the if-statement if @delay is a constant.
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| 52 |
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| 53 | #define spin_event_timeout(condition, timeout, delay) \
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| 54 | ({ \
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| 55 | typeof(condition) __ret; \
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| 56 | unsigned long __loops = tb_ticks_per_usec * timeout; \
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| 57 | unsigned long __start = mftb(); \
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| 58 | \
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| 59 | if (delay) { \
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| 60 | while (!(__ret = (condition)) && \
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| 61 | (tb_ticks_since(__start) <= __loops)) \
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| 62 | udelay(delay); \
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| 63 | } else { \
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| 64 | spin_begin(); \
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| 65 | while (!(__ret = (condition)) && \
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| 66 | (tb_ticks_since(__start) <= __loops)) \
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| 67 | spin_cpu_relax(); \
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| 68 | spin_end(); \
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| 69 | } \
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| 70 | if (!__ret) \
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| 71 | __ret = (condition); \
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| 72 | __ret; \
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| 73 | })
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| 74 |
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| 75 | #endif
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| 76 | #endif
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