2 * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 and
6 * only version 2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
15 #ifndef _LINUX_IOPOLL_H
16 #define _LINUX_IOPOLL_H
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/hrtimer.h>
21 #include <linux/delay.h>
22 #include <linux/errno.h>
26 * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
27 * @op: accessor function (takes @addr as its only argument)
28 * @addr: Address to poll
29 * @val: Variable to read the value into
30 * @cond: Break condition (usually involving @val)
31 * @sleep_us: Maximum time to sleep between reads in us (0
32 * tight-loops). Should be less than ~20ms since usleep_range
33 * is used (see Documentation/timers/timers-howto.txt).
34 * @timeout_us: Timeout in us, 0 means never timeout
36 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
37 * case, the last read value at @addr is stored in @val. Must not
38 * be called from atomic context if sleep_us or timeout_us are used.
40 * When available, you'll probably want to use one of the specialized
41 * macros defined below rather than this macro directly.
43 #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
45 ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
46 might_sleep_if(sleep_us); \
51 if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
56 usleep_range((sleep_us >> 2) + 1, sleep_us); \
58 (cond) ? 0 : -ETIMEDOUT; \
62 * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs
63 * @op: accessor function (takes @addr as its only argument)
64 * @addr: Address to poll
65 * @val: Variable to read the value into
66 * @cond: Break condition (usually involving @val)
67 * @delay_us: Time to udelay between reads in us (0 tight-loops). Should
68 * be less than ~10us since udelay is used (see
69 * Documentation/timers/timers-howto.txt).
70 * @timeout_us: Timeout in us, 0 means never timeout
72 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
73 * case, the last read value at @addr is stored in @val.
75 * When available, you'll probably want to use one of the specialized
76 * macros defined below rather than this macro directly.
78 #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \
80 ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
85 if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
92 (cond) ? 0 : -ETIMEDOUT; \
96 #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \
97 readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us)
99 #define readb_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
100 readx_poll_timeout_atomic(readb, addr, val, cond, delay_us, timeout_us)
102 #define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \
103 readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us)
105 #define readw_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
106 readx_poll_timeout_atomic(readw, addr, val, cond, delay_us, timeout_us)
108 #define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
109 readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us)
111 #define readl_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
112 readx_poll_timeout_atomic(readl, addr, val, cond, delay_us, timeout_us)
114 #define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \
115 readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us)
117 #define readq_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
118 readx_poll_timeout_atomic(readq, addr, val, cond, delay_us, timeout_us)
120 #define readb_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
121 readx_poll_timeout(readb_relaxed, addr, val, cond, delay_us, timeout_us)
123 #define readb_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
124 readx_poll_timeout_atomic(readb_relaxed, addr, val, cond, delay_us, timeout_us)
126 #define readw_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
127 readx_poll_timeout(readw_relaxed, addr, val, cond, delay_us, timeout_us)
129 #define readw_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
130 readx_poll_timeout_atomic(readw_relaxed, addr, val, cond, delay_us, timeout_us)
132 #define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
133 readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
135 #define readl_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
136 readx_poll_timeout_atomic(readl_relaxed, addr, val, cond, delay_us, timeout_us)
138 #define readq_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
139 readx_poll_timeout(readq_relaxed, addr, val, cond, delay_us, timeout_us)
141 #define readq_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
142 readx_poll_timeout_atomic(readq_relaxed, addr, val, cond, delay_us, timeout_us)
144 #endif /* _LINUX_IOPOLL_H */
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