1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
6 #ifndef _LINUX_IOPOLL_H
7 #define _LINUX_IOPOLL_H
9 #include <linux/errno.h>
14 * read_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
21 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
22 * case, the last read value at @addr is stored in @val.
24 * When available, you'll probably want to use one of the specialized
25 * macros defined below rather than this macro directly.
27 #define read_poll_timeout(op, addr, val, cond, timeout_us) \
29 unsigned long timeout = timer_get_us() + timeout_us; \
34 if (timeout_us && time_after(timer_get_us(), timeout)) { \
39 (cond) ? 0 : -ETIMEDOUT; \
42 #define readx_poll_timeout(op, addr, val, cond, timeout_us) \
43 read_poll_timeout(op, addr, val, cond, timeout_us)
45 #define readb_poll_timeout(addr, val, cond, timeout_us) \
46 readx_poll_timeout(readb, addr, val, cond, timeout_us)
48 #define readw_poll_timeout(addr, val, cond, timeout_us) \
49 readx_poll_timeout(readw, addr, val, cond, timeout_us)
51 #define readl_poll_timeout(addr, val, cond, timeout_us) \
52 readx_poll_timeout(readl, addr, val, cond, timeout_us)
54 #define readq_poll_timeout(addr, val, cond, timeout_us) \
55 readx_poll_timeout(readq, addr, val, cond, timeout_us)
57 #define readb_relaxed_poll_timeout(addr, val, cond, timeout_us) \
58 readx_poll_timeout(readb_relaxed, addr, val, cond, timeout_us)
60 #define readw_relaxed_poll_timeout(addr, val, cond, timeout_us) \
61 readx_poll_timeout(readw_relaxed, addr, val, cond, timeout_us)
63 #define readl_relaxed_poll_timeout(addr, val, cond, timeout_us) \
64 readx_poll_timeout(readl_relaxed, addr, val, cond, timeout_us)
66 #define readq_relaxed_poll_timeout(addr, val, cond, timeout_us) \
67 readx_poll_timeout(readq_relaxed, addr, val, cond, timeout_us)
69 #endif /* _LINUX_IOPOLL_H */