/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved. */ #ifndef _LINUX_IOPOLL_H #define _LINUX_IOPOLL_H #include <linux/kernel.h> #include <linux/types.h> #include <linux/ktime.h> #include <linux/delay.h> #include <linux/errno.h> #include <linux/io.h> /** * poll_timeout_us - Periodically poll and perform an operation until * a condition is met or a timeout occurs * * @op: Operation * @cond: Break condition * @sleep_us: Maximum time to sleep between operations in us (0 tight-loops). * Please read usleep_range() function description for details and * limitations. * @timeout_us: Timeout in us, 0 means never timeout * @sleep_before_op: if it is true, sleep @sleep_us before operation. * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. * * Returns: 0 on success and -ETIMEDOUT upon a timeout. Must not * be called from atomic context if sleep_us or timeout_us are used. */ #define poll_timeout_us(op, cond, sleep_us, timeout_us, sleep_before_op) \ ({ \ u64 __timeout_us = (timeout_us); \ unsigned long __sleep_us = (sleep_us); \ ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ int ___ret; \ might_sleep_if((__sleep_us) != 0); \ if ((sleep_before_op) && __sleep_us) \ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ for (;;) { \ bool __expired = __timeout_us && \ ktime_compare(ktime_get(), __timeout) > 0; \ /* guarantee 'op' and 'cond' are evaluated after timeout expired */ \ barrier(); \ op; \ if (cond) { \ ___ret = 0; \ break; \ } \ if (__expired) { \ ___ret = -ETIMEDOUT; \ break; \ } \ if (__sleep_us) \ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ cpu_relax(); \ } \ ___ret; \ }) /** * poll_timeout_us_atomic - Periodically poll and perform an operation until * a condition is met or a timeout occurs * * @op: Operation * @cond: Break condition * @delay_us: Time to udelay between operations in us (0 tight-loops). * Please read udelay() function description for details and * limitations. * @timeout_us: Timeout in us, 0 means never timeout * @delay_before_op: if it is true, delay @delay_us before operation. * * This macro does not rely on timekeeping. Hence it is safe to call even when * timekeeping is suspended, at the expense of an underestimation of wall clock * time, which is rather minimal with a non-zero delay_us. * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. * * Returns: 0 on success and -ETIMEDOUT upon a timeout. */ #define poll_timeout_us_atomic(op, cond, delay_us, timeout_us, \ delay_before_op) \ ({ \ u64 __timeout_us = (timeout_us); \ s64 __left_ns = __timeout_us * NSEC_PER_USEC; \ unsigned long __delay_us = (delay_us); \ u64 __delay_ns = __delay_us * NSEC_PER_USEC; \ int ___ret; \ if ((delay_before_op) && __delay_us) { \ udelay(__delay_us); \ if (__timeout_us) \ __left_ns -= __delay_ns; \ } \ for (;;) { \ bool __expired = __timeout_us && __left_ns < 0; \ /* guarantee 'op' and 'cond' are evaluated after timeout expired */ \ barrier(); \ op; \ if (cond) { \ ___ret = 0; \ break; \ } \ if (__expired) { \ ___ret = -ETIMEDOUT; \ break; \ } \ if (__delay_us) { \ udelay(__delay_us); \ if (__timeout_us) \ __left_ns -= __delay_ns; \ } \ cpu_relax(); \ if (__timeout_us) \ __left_ns--; \ } \ ___ret; \ }) /** * read_poll_timeout - Periodically poll an address until a condition is * met or a timeout occurs * @op: accessor function (takes @args as its arguments) * @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). Please * read usleep_range() function description for details and * limitations. * @timeout_us: Timeout in us, 0 means never timeout * @sleep_before_read: if it is true, sleep @sleep_us before read. * @args: arguments for @op poll * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. * * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @args is stored in @val. Must not * be called from atomic context if sleep_us or timeout_us are used. */ #define read_poll_timeout(op, val, cond, sleep_us, timeout_us, \ sleep_before_read, args...) \ poll_timeout_us((val) = op(args), cond, sleep_us, timeout_us, sleep_before_read) /** * read_poll_timeout_atomic - Periodically poll an address until a condition is * met or a timeout occurs * @op: accessor function (takes @args as its arguments) * @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). Please * read udelay() function description for details and * limitations. * @timeout_us: Timeout in us, 0 means never timeout * @delay_before_read: if it is true, delay @delay_us before read. * @args: arguments for @op poll * * This macro does not rely on timekeeping. Hence it is safe to call even when * timekeeping is suspended, at the expense of an underestimation of wall clock * time, which is rather minimal with a non-zero delay_us. * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. * * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @args is stored in @val. */ #define read_poll_timeout_atomic(op, val, cond, sleep_us, timeout_us, \ sleep_before_read, args...) \ poll_timeout_us_atomic((val) = op(args), cond, sleep_us, timeout_us, sleep_before_read) /** * 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). Please * read usleep_range() function description for details and * limitations. * @timeout_us: Timeout in us, 0 means never timeout * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. * * 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. */ #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \ read_poll_timeout(op, val, cond, sleep_us, timeout_us, false, addr) /** * 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). Please * read udelay() function description for details and * limitations. * @timeout_us: Timeout in us, 0 means never timeout * * When available, you'll probably want to use one of the specialized * macros defined below rather than this macro directly. * * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @addr is stored in @val. */ #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \ read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, false, addr) #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 */
