#ifndef _ASM_POWERPC_DELAY_H #define _ASM_POWERPC_DELAY_H #ifdef __KERNEL__ #include <asm/time.h> /* * Copyright 1996, Paul Mackerras. * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan, * Anton Blanchard. */ extern void __delay(unsigned long loops); extern void udelay(unsigned long usecs); /* * On shared processor machines the generic implementation of mdelay can * result in large errors. While each iteration of the loop inside mdelay * is supposed to take 1ms, the hypervisor could sleep our partition for * longer (eg 10ms). With the right timing these errors can add up. * * Since there is no 32bit overflow issue on 64bit kernels, just call * udelay directly. */ #ifdef [31mCONFIG_PPC64[0m #define mdelay(n) udelay((n) * 1000) #endif /** * spin_event_timeout - spin until a condition gets true or a timeout elapses * @condition: a C expression to evalate * @timeout: timeout, in microseconds * @delay: the number of microseconds to delay between each evaluation of * @condition * * The process spins until the condition evaluates to true (non-zero) or the * timeout elapses. The return value of this macro is the value of * @condition when the loop terminates. This allows you to determine the cause * of the loop terminates. If the return value is zero, then you know a * timeout has occurred. * * This primary purpose of this macro is to poll on a hardware register * until a status bit changes. The timeout ensures that the loop still * terminates even if the bit never changes. The delay is for devices that * need a delay in between successive reads. * * gcc will optimize out the if-statement if @delay is a constant. */ #define spin_event_timeout(condition, timeout, delay) \ ({ \ typeof(condition) __ret; \ unsigned long __loops = tb_ticks_per_usec * timeout; \ unsigned long __start = get_tbl(); \ while (!(__ret = (condition)) && (tb_ticks_since(__start) <= __loops)) \ if (delay) \ udelay(delay); \ else \ cpu_relax(); \ if (!__ret) \ __ret = (condition); \ __ret; \ }) #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_DELAY_H */ |