Edit File: iopoll.h
/* * Copyright (c) 2012-2014 The Linux Foundation. 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 version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #ifndef _LINUX_IOPOLL_H #define _LINUX_IOPOLL_H #include <linux/kernel.h> #include <linux/types.h> #include <linux/hrtimer.h> #include <linux/delay.h> #include <linux/errno.h> #include <linux/io.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) * @sleep_us: Maximum time to sleep between reads in us (0 * tight-loops). Should be less than ~20ms since usleep_range * is used (see Documentation/timers/timers-howto.txt). * @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. Must not * be called from atomic context if sleep_us or timeout_us are used. * * 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, sleep_us, timeout_us) \ ({ \ ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \ might_sleep_if(sleep_us); \ for (;;) { \ (val) = op(addr); \ if (cond) \ break; \ if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \ (val) = op(addr); \ break; \ } \ if (sleep_us) \ usleep_range((sleep_us >> 2) + 1, sleep_us); \ } \ (cond) ? 0 : -ETIMEDOUT; \ }) /** * readx_poll_timeout_atomic - 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) * @delay_us: Time to udelay between reads in us (0 tight-loops). Should * be less than ~10us since udelay is used (see * Documentation/timers/timers-howto.txt). * @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_atomic(op, addr, val, cond, delay_us, timeout_us) \ ({ \ ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \ for (;;) { \ (val) = op(addr); \ if (cond) \ break; \ if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \ (val) = op(addr); \ break; \ } \ if (delay_us) \ udelay(delay_us); \ } \ (cond) ? 0 : -ETIMEDOUT; \ }) #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us) #define readb_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readb, addr, val, cond, delay_us, timeout_us) #define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us) #define readw_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readw, addr, val, cond, delay_us, timeout_us) #define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us) #define readl_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readl, addr, val, cond, delay_us, timeout_us) #define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us) #define readq_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readq, addr, val, cond, delay_us, timeout_us) #define readb_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readb_relaxed, addr, val, cond, delay_us, timeout_us) #define readb_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readb_relaxed, addr, val, cond, delay_us, timeout_us) #define readw_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readw_relaxed, addr, val, cond, delay_us, timeout_us) #define readw_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readw_relaxed, addr, val, cond, delay_us, timeout_us) #define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us) #define readl_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readl_relaxed, addr, val, cond, delay_us, timeout_us) #define readq_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout(readq_relaxed, addr, val, cond, delay_us, timeout_us) #define readq_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ readx_poll_timeout_atomic(readq_relaxed, addr, val, cond, delay_us, timeout_us) #endif /* _LINUX_IOPOLL_H */