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97fb5e8d | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
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2 | /* |
3 | * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved. | |
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4 | */ |
5 | ||
6 | #ifndef _LINUX_IOPOLL_H | |
7 | #define _LINUX_IOPOLL_H | |
8 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/types.h> | |
16f4e319 | 11 | #include <linux/ktime.h> |
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12 | #include <linux/delay.h> |
13 | #include <linux/errno.h> | |
14 | #include <linux/io.h> | |
15 | ||
16 | /** | |
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 | |
458f69ef | 24 | * is used (see Documentation/timers/timers-howto.rst). |
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25 | * @timeout_us: Timeout in us, 0 means never timeout |
26 | * | |
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. | |
30 | * | |
31 | * When available, you'll probably want to use one of the specialized | |
32 | * macros defined below rather than this macro directly. | |
33 | */ | |
34 | #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \ | |
35 | ({ \ | |
d15809f3 AB |
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); \ | |
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40 | for (;;) { \ |
41 | (val) = op(addr); \ | |
42 | if (cond) \ | |
43 | break; \ | |
d15809f3 AB |
44 | if (__timeout_us && \ |
45 | ktime_compare(ktime_get(), __timeout) > 0) { \ | |
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46 | (val) = op(addr); \ |
47 | break; \ | |
48 | } \ | |
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49 | if (__sleep_us) \ |
50 | usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ | |
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51 | } \ |
52 | (cond) ? 0 : -ETIMEDOUT; \ | |
53 | }) | |
54 | ||
55 | /** | |
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 | |
458f69ef | 63 | * Documentation/timers/timers-howto.rst). |
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64 | * @timeout_us: Timeout in us, 0 means never timeout |
65 | * | |
66 | * Returns 0 on success and -ETIMEDOUT upon a timeout. In either | |
67 | * case, the last read value at @addr is stored in @val. | |
68 | * | |
69 | * When available, you'll probably want to use one of the specialized | |
70 | * macros defined below rather than this macro directly. | |
71 | */ | |
72 | #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \ | |
73 | ({ \ | |
d15809f3 AB |
74 | u64 __timeout_us = (timeout_us); \ |
75 | unsigned long __delay_us = (delay_us); \ | |
76 | ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ | |
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77 | for (;;) { \ |
78 | (val) = op(addr); \ | |
79 | if (cond) \ | |
80 | break; \ | |
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81 | if (__timeout_us && \ |
82 | ktime_compare(ktime_get(), __timeout) > 0) { \ | |
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83 | (val) = op(addr); \ |
84 | break; \ | |
85 | } \ | |
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86 | if (__delay_us) \ |
87 | udelay(__delay_us); \ | |
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88 | } \ |
89 | (cond) ? 0 : -ETIMEDOUT; \ | |
90 | }) | |
91 | ||
92 | ||
93 | #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \ | |
94 | readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us) | |
95 | ||
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) | |
98 | ||
99 | #define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \ | |
100 | readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us) | |
101 | ||
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) | |
104 | ||
105 | #define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \ | |
106 | readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us) | |
107 | ||
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) | |
110 | ||
111 | #define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \ | |
112 | readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us) | |
113 | ||
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) | |
116 | ||
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) | |
119 | ||
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) | |
122 | ||
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) | |
125 | ||
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) | |
128 | ||
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) | |
131 | ||
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) | |
134 | ||
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) | |
137 | ||
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) | |
140 | ||
141 | #endif /* _LINUX_IOPOLL_H */ |