| 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
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| 2 | /* |
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| 3 | * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved. |
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| 4 | */ |
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| 5 | |
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| 6 | #ifndef _LINUX_IOPOLL_H |
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| 7 | #define _LINUX_IOPOLL_H |
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| 8 | |
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| 9 | #include <linux/kernel.h> |
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| 10 | #include <linux/types.h> |
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| 11 | #include <linux/ktime.h> |
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| 12 | #include <linux/delay.h> |
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| 13 | #include <linux/errno.h> |
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| 14 | #include <linux/io.h> |
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| 15 | |
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| 16 | /** |
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| 17 | * read_poll_timeout - Periodically poll an address until a condition is |
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| 18 | * met or a timeout occurs |
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| 19 | * @op: accessor function (takes @args as its arguments) |
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| 20 | * @val: Variable to read the value into |
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| 21 | * @cond: Break condition (usually involving @val) |
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| 22 | * @sleep_us: Maximum time to sleep between reads in us (0 tight-loops). Please |
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| 23 | * read usleep_range() function description for details and |
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| 24 | * limitations. |
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| 25 | * @timeout_us: Timeout in us, 0 means never timeout |
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| 26 | * @sleep_before_read: if it is true, sleep @sleep_us before read. |
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| 27 | * @args: arguments for @op poll |
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| 28 | * |
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| 29 | * When available, you'll probably want to use one of the specialized |
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| 30 | * macros defined below rather than this macro directly. |
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| 31 | * |
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| 32 | * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either |
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| 33 | * case, the last read value at @args is stored in @val. Must not |
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| 34 | * be called from atomic context if sleep_us or timeout_us are used. |
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| 35 | */ |
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| 36 | #define read_poll_timeout(op, val, cond, sleep_us, timeout_us, \ |
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| 37 | sleep_before_read, args...) \ |
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| 38 | ({ \ |
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| 39 | u64 __timeout_us = (timeout_us); \ |
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| 40 | unsigned long __sleep_us = (sleep_us); \ |
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| 41 | ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ |
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| 42 | might_sleep_if((__sleep_us) != 0); \ |
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| 43 | if (sleep_before_read && __sleep_us) \ |
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| 44 | usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ |
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| 45 | for (;;) { \ |
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| 46 | (val) = op(args); \ |
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| 47 | if (cond) \ |
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| 48 | break; \ |
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| 49 | if (__timeout_us && \ |
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| 50 | ktime_compare(ktime_get(), __timeout) > 0) { \ |
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| 51 | (val) = op(args); \ |
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| 52 | break; \ |
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| 53 | } \ |
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| 54 | if (__sleep_us) \ |
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| 55 | usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ |
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| 56 | cpu_relax(); \ |
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| 57 | } \ |
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| 58 | (cond) ? 0 : -ETIMEDOUT; \ |
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| 59 | }) |
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| 60 | |
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| 61 | /** |
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| 62 | * read_poll_timeout_atomic - Periodically poll an address until a condition is |
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| 63 | * met or a timeout occurs |
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| 64 | * @op: accessor function (takes @args as its arguments) |
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| 65 | * @val: Variable to read the value into |
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| 66 | * @cond: Break condition (usually involving @val) |
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| 67 | * @delay_us: Time to udelay between reads in us (0 tight-loops). Please |
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| 68 | * read udelay() function description for details and |
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| 69 | * limitations. |
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| 70 | * @timeout_us: Timeout in us, 0 means never timeout |
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| 71 | * @delay_before_read: if it is true, delay @delay_us before read. |
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| 72 | * @args: arguments for @op poll |
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| 73 | * |
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| 74 | * This macro does not rely on timekeeping. Hence it is safe to call even when |
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| 75 | * timekeeping is suspended, at the expense of an underestimation of wall clock |
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| 76 | * time, which is rather minimal with a non-zero delay_us. |
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| 77 | * |
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| 78 | * When available, you'll probably want to use one of the specialized |
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| 79 | * macros defined below rather than this macro directly. |
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| 80 | * |
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| 81 | * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either |
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| 82 | * case, the last read value at @args is stored in @val. |
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| 83 | */ |
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| 84 | #define read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, \ |
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| 85 | delay_before_read, args...) \ |
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| 86 | ({ \ |
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| 87 | u64 __timeout_us = (timeout_us); \ |
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| 88 | s64 __left_ns = __timeout_us * NSEC_PER_USEC; \ |
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| 89 | unsigned long __delay_us = (delay_us); \ |
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| 90 | u64 __delay_ns = __delay_us * NSEC_PER_USEC; \ |
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| 91 | if (delay_before_read && __delay_us) { \ |
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| 92 | udelay(__delay_us); \ |
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| 93 | if (__timeout_us) \ |
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| 94 | __left_ns -= __delay_ns; \ |
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| 95 | } \ |
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| 96 | for (;;) { \ |
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| 97 | (val) = op(args); \ |
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| 98 | if (cond) \ |
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| 99 | break; \ |
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| 100 | if (__timeout_us && __left_ns < 0) { \ |
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| 101 | (val) = op(args); \ |
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| 102 | break; \ |
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| 103 | } \ |
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| 104 | if (__delay_us) { \ |
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| 105 | udelay(__delay_us); \ |
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| 106 | if (__timeout_us) \ |
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| 107 | __left_ns -= __delay_ns; \ |
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| 108 | } \ |
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| 109 | cpu_relax(); \ |
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| 110 | if (__timeout_us) \ |
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| 111 | __left_ns--; \ |
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| 112 | } \ |
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| 113 | (cond) ? 0 : -ETIMEDOUT; \ |
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| 114 | }) |
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| 115 | |
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| 116 | /** |
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| 117 | * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs |
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| 118 | * @op: accessor function (takes @addr as its only argument) |
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| 119 | * @addr: Address to poll |
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| 120 | * @val: Variable to read the value into |
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| 121 | * @cond: Break condition (usually involving @val) |
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| 122 | * @sleep_us: Maximum time to sleep between reads in us (0 tight-loops). Please |
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| 123 | * read usleep_range() function description for details and |
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| 124 | * limitations. |
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| 125 | * @timeout_us: Timeout in us, 0 means never timeout |
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| 126 | * |
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| 127 | * When available, you'll probably want to use one of the specialized |
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| 128 | * macros defined below rather than this macro directly. |
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| 129 | * |
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| 130 | * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either |
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| 131 | * case, the last read value at @addr is stored in @val. Must not |
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| 132 | * be called from atomic context if sleep_us or timeout_us are used. |
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| 133 | */ |
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| 134 | #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \ |
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| 135 | read_poll_timeout(op, val, cond, sleep_us, timeout_us, false, addr) |
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| 136 | |
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| 137 | /** |
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| 138 | * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs |
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| 139 | * @op: accessor function (takes @addr as its only argument) |
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| 140 | * @addr: Address to poll |
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| 141 | * @val: Variable to read the value into |
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| 142 | * @cond: Break condition (usually involving @val) |
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| 143 | * @delay_us: Time to udelay between reads in us (0 tight-loops). Please |
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| 144 | * read udelay() function description for details and |
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| 145 | * limitations. |
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| 146 | * @timeout_us: Timeout in us, 0 means never timeout |
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| 147 | * |
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| 148 | * When available, you'll probably want to use one of the specialized |
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| 149 | * macros defined below rather than this macro directly. |
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| 150 | * |
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| 151 | * Returns: 0 on success and -ETIMEDOUT upon a timeout. In either |
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| 152 | * case, the last read value at @addr is stored in @val. |
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| 153 | */ |
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| 154 | #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \ |
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| 155 | read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, false, addr) |
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| 156 | |
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| 157 | #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 158 | readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us) |
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| 159 | |
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| 160 | #define readb_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 161 | readx_poll_timeout_atomic(readb, addr, val, cond, delay_us, timeout_us) |
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| 162 | |
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| 163 | #define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 164 | readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us) |
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| 165 | |
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| 166 | #define readw_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 167 | readx_poll_timeout_atomic(readw, addr, val, cond, delay_us, timeout_us) |
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| 168 | |
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| 169 | #define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 170 | readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us) |
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| 171 | |
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| 172 | #define readl_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 173 | readx_poll_timeout_atomic(readl, addr, val, cond, delay_us, timeout_us) |
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| 174 | |
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| 175 | #define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 176 | readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us) |
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| 177 | |
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| 178 | #define readq_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 179 | readx_poll_timeout_atomic(readq, addr, val, cond, delay_us, timeout_us) |
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| 180 | |
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| 181 | #define readb_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 182 | readx_poll_timeout(readb_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 183 | |
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| 184 | #define readb_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 185 | readx_poll_timeout_atomic(readb_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 186 | |
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| 187 | #define readw_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 188 | readx_poll_timeout(readw_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 189 | |
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| 190 | #define readw_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 191 | readx_poll_timeout_atomic(readw_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 192 | |
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| 193 | #define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 194 | readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 195 | |
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| 196 | #define readl_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 197 | readx_poll_timeout_atomic(readl_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 198 | |
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| 199 | #define readq_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \ |
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| 200 | readx_poll_timeout(readq_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 201 | |
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| 202 | #define readq_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \ |
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| 203 | readx_poll_timeout_atomic(readq_relaxed, addr, val, cond, delay_us, timeout_us) |
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| 204 | |
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| 205 | #endif /* _LINUX_IOPOLL_H */ |
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| 206 | |
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