1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
6 #ifndef _LINUX_IOPOLL_H
7 #define _LINUX_IOPOLL_H
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/ktime.h>
12 #include <linux/delay.h>
13 #include <linux/errno.h>
17 * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
18 * @op: accessor function (takes @addr as its only argument)
19 * @addr: Address to poll
20 * @val: Variable to read the value into
21 * @cond: Break condition (usually involving @val)
22 * @sleep_us: Maximum time to sleep between reads in us (0
23 * tight-loops). Should be less than ~20ms since usleep_range
24 * is used (see Documentation/timers/timers-howto.rst).
25 * @timeout_us: Timeout in us, 0 means never timeout
27 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
28 * case, the last read value at @addr is stored in @val. Must not
29 * be called from atomic context if sleep_us or timeout_us are used.
31 * When available, you'll probably want to use one of the specialized
32 * macros defined below rather than this macro directly.
34 #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
36 u64 __timeout_us = (timeout_us); \
37 unsigned long __sleep_us = (sleep_us); \
38 ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
39 might_sleep_if((__sleep_us) != 0); \
45 ktime_compare(ktime_get(), __timeout) > 0) { \
50 usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
52 (cond) ? 0 : -ETIMEDOUT; \
56 * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs
57 * @op: accessor function (takes @addr as its only argument)
58 * @addr: Address to poll
59 * @val: Variable to read the value into
60 * @cond: Break condition (usually involving @val)
61 * @delay_us: Time to udelay between reads in us (0 tight-loops). Should
62 * be less than ~10us since udelay is used (see
63 * Documentation/timers/timers-howto.rst).
64 * @timeout_us: Timeout in us, 0 means never timeout
66 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
67 * case, the last read value at @addr is stored in @val.
69 * When available, you'll probably want to use one of the specialized
70 * macros defined below rather than this macro directly.
72 #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \
74 u64 __timeout_us = (timeout_us); \
75 unsigned long __delay_us = (delay_us); \
76 ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
82 ktime_compare(ktime_get(), __timeout) > 0) { \
89 (cond) ? 0 : -ETIMEDOUT; \
93 #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \
94 readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us)
96 #define readb_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
97 readx_poll_timeout_atomic(readb, addr, val, cond, delay_us, timeout_us)
99 #define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \
100 readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us)
102 #define readw_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
103 readx_poll_timeout_atomic(readw, addr, val, cond, delay_us, timeout_us)
105 #define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
106 readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us)
108 #define readl_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
109 readx_poll_timeout_atomic(readl, addr, val, cond, delay_us, timeout_us)
111 #define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \
112 readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us)
114 #define readq_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
115 readx_poll_timeout_atomic(readq, addr, val, cond, delay_us, timeout_us)
117 #define readb_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
118 readx_poll_timeout(readb_relaxed, addr, val, cond, delay_us, timeout_us)
120 #define readb_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
121 readx_poll_timeout_atomic(readb_relaxed, addr, val, cond, delay_us, timeout_us)
123 #define readw_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
124 readx_poll_timeout(readw_relaxed, addr, val, cond, delay_us, timeout_us)
126 #define readw_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
127 readx_poll_timeout_atomic(readw_relaxed, addr, val, cond, delay_us, timeout_us)
129 #define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
130 readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
132 #define readl_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
133 readx_poll_timeout_atomic(readl_relaxed, addr, val, cond, delay_us, timeout_us)
135 #define readq_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
136 readx_poll_timeout(readq_relaxed, addr, val, cond, delay_us, timeout_us)
138 #define readq_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
139 readx_poll_timeout_atomic(readq_relaxed, addr, val, cond, delay_us, timeout_us)
141 #endif /* _LINUX_IOPOLL_H */