1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved. 4 */ 5 6 #ifndef _LINUX_IOPOLL_H 7 #define _LINUX_IOPOLL_H 8 9 #include <linux/errno.h> 10 #include <linux/io.h> 11 #include <time.h> 12 13 /** 14 * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs 15 * @op: accessor function (takes @addr as its only argument) 16 * @addr: Address to poll 17 * @val: Variable to read the value into 18 * @cond: Break condition (usually involving @val) 19 * @timeout_us: Timeout in us, 0 means never timeout 20 * 21 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either 22 * case, the last read value at @addr is stored in @val. 23 * 24 * When available, you'll probably want to use one of the specialized 25 * macros defined below rather than this macro directly. 26 */ 27 #define readx_poll_timeout(op, addr, val, cond, timeout_us) \ 28 ({ \ 29 unsigned long timeout = timer_get_us() + timeout_us; \ 30 for (;;) { \ 31 (val) = op(addr); \ 32 if (cond) \ 33 break; \ 34 if (timeout_us && time_after(timer_get_us(), timeout)) { \ 35 (val) = op(addr); \ 36 break; \ 37 } \ 38 } \ 39 (cond) ? 0 : -ETIMEDOUT; \ 40 }) 41 42 43 #define readb_poll_timeout(addr, val, cond, timeout_us) \ 44 readx_poll_timeout(readb, addr, val, cond, timeout_us) 45 46 #define readw_poll_timeout(addr, val, cond, timeout_us) \ 47 readx_poll_timeout(readw, addr, val, cond, timeout_us) 48 49 #define readl_poll_timeout(addr, val, cond, timeout_us) \ 50 readx_poll_timeout(readl, addr, val, cond, timeout_us) 51 52 #define readq_poll_timeout(addr, val, cond, timeout_us) \ 53 readx_poll_timeout(readq, addr, val, cond, timeout_us) 54 55 #define readb_relaxed_poll_timeout(addr, val, cond, timeout_us) \ 56 readx_poll_timeout(readb_relaxed, addr, val, cond, timeout_us) 57 58 #define readw_relaxed_poll_timeout(addr, val, cond, timeout_us) \ 59 readx_poll_timeout(readw_relaxed, addr, val, cond, timeout_us) 60 61 #define readl_relaxed_poll_timeout(addr, val, cond, timeout_us) \ 62 readx_poll_timeout(readl_relaxed, addr, val, cond, timeout_us) 63 64 #define readq_relaxed_poll_timeout(addr, val, cond, timeout_us) \ 65 readx_poll_timeout(readq_relaxed, addr, val, cond, timeout_us) 66 67 #endif /* _LINUX_IOPOLL_H */ 68