151 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			151 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 and
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 * only version 2 as published by the Free Software Foundation.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 */
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#ifndef _LINUX_IOPOLL_H
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#define _LINUX_IOPOLL_H
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/ktime.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/io.h>
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/**
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 * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
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 * @op: accessor function (takes @addr as its only argument)
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 * @addr: Address to poll
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 * @val: Variable to read the value into
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 * @cond: Break condition (usually involving @val)
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 * @sleep_us: Maximum time to sleep between reads in us (0
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 *            tight-loops).  Should be less than ~20ms since usleep_range
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 *            is used (see Documentation/timers/timers-howto.txt).
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 * @timeout_us: Timeout in us, 0 means never timeout
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 *
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 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
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 * case, the last read value at @addr is stored in @val. Must not
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 * be called from atomic context if sleep_us or timeout_us are used.
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 *
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 * When available, you'll probably want to use one of the specialized
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 * macros defined below rather than this macro directly.
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 */
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#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us)	\
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({ \
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	u64 __timeout_us = (timeout_us); \
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	unsigned long __sleep_us = (sleep_us); \
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	ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
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	might_sleep_if((__sleep_us) != 0); \
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	for (;;) { \
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		(val) = op(addr); \
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		if (cond) \
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			break; \
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		if (__timeout_us && \
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		    ktime_compare(ktime_get(), __timeout) > 0) { \
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			(val) = op(addr); \
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			break; \
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		} \
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		if (__sleep_us) \
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			usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
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	} \
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	(cond) ? 0 : -ETIMEDOUT; \
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})
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/**
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 * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs
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 * @op: accessor function (takes @addr as its only argument)
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 * @addr: Address to poll
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 * @val: Variable to read the value into
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 * @cond: Break condition (usually involving @val)
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 * @delay_us: Time to udelay between reads in us (0 tight-loops).  Should
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 *            be less than ~10us since udelay is used (see
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 *            Documentation/timers/timers-howto.txt).
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 * @timeout_us: Timeout in us, 0 means never timeout
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 *
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 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
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 * case, the last read value at @addr is stored in @val.
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 *
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 * When available, you'll probably want to use one of the specialized
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 * macros defined below rather than this macro directly.
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 */
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#define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \
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({ \
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	u64 __timeout_us = (timeout_us); \
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	unsigned long __delay_us = (delay_us); \
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	ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
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	for (;;) { \
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		(val) = op(addr); \
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		if (cond) \
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			break; \
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		if (__timeout_us && \
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		    ktime_compare(ktime_get(), __timeout) > 0) { \
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			(val) = op(addr); \
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			break; \
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		} \
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		if (__delay_us) \
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			udelay(__delay_us);	\
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	} \
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	(cond) ? 0 : -ETIMEDOUT; \
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})
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#define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us)
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#define readb_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readb, addr, val, cond, delay_us, timeout_us)
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#define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us)
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#define readw_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readw, addr, val, cond, delay_us, timeout_us)
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#define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us)
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#define readl_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readl, addr, val, cond, delay_us, timeout_us)
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#define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us)
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#define readq_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readq, addr, val, cond, delay_us, timeout_us)
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#define readb_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readb_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readb_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readb_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readw_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readw_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readw_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readw_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readl_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readl_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readq_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout(readq_relaxed, addr, val, cond, delay_us, timeout_us)
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#define readq_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
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	readx_poll_timeout_atomic(readq_relaxed, addr, val, cond, delay_us, timeout_us)
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#endif /* _LINUX_IOPOLL_H */
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