iopoll.h
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/*
* Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0
*/
#ifndef _LINUX_IOPOLL_H
#define _LINUX_IOPOLL_H
#include <linux/errno.h>
#include <linux/io.h>
#include <time.h>
/**
* readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
* @op: accessor function (takes @addr as its only argument)
* @addr: Address to poll
* @val: Variable to read the value into
* @cond: Break condition (usually involving @val)
* @timeout_us: Timeout in us, 0 means never timeout
*
* Returns 0 on success and -ETIMEDOUT upon a timeout. In either
* case, the last read value at @addr is stored in @val.
*
* When available, you'll probably want to use one of the specialized
* macros defined below rather than this macro directly.
*/
#define readx_poll_timeout(op, addr, val, cond, timeout_us) \
({ \
unsigned long timeout = timer_get_us() + timeout_us; \
for (;;) { \
(val) = op(addr); \
if (cond) \
break; \
if (timeout_us && time_after(timer_get_us(), timeout)) { \
(val) = op(addr); \
break; \
} \
} \
(cond) ? 0 : -ETIMEDOUT; \
})
#define readb_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readb, addr, val, cond, timeout_us)
#define readw_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readw, addr, val, cond, timeout_us)
#define readl_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readl, addr, val, cond, timeout_us)
#define readq_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readq, addr, val, cond, timeout_us)
#define readb_relaxed_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readb_relaxed, addr, val, cond, timeout_us)
#define readw_relaxed_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readw_relaxed, addr, val, cond, timeout_us)
#define readl_relaxed_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readl_relaxed, addr, val, cond, timeout_us)
#define readq_relaxed_poll_timeout(addr, val, cond, timeout_us) \
readx_poll_timeout(readq_relaxed, addr, val, cond, timeout_us)
#endif /* _LINUX_IOPOLL_H */