hc
2024-05-10 23fa18eaa71266feff7ba8d83022d9e1cc83c65a
kernel/include/linux/iopoll.h
....@@ -1,15 +1,6 @@
1
+/* SPDX-License-Identifier: GPL-2.0-only */
12 /*
23 * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
3
- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2 and
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- * only version 2 as published by the Free Software Foundation.
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- *
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- * This program is distributed in the hope that it will be useful,
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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- * GNU General Public License for more details.
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- *
134 */
145
156 #ifndef _LINUX_IOPOLL_H
....@@ -23,6 +14,94 @@
2314 #include <linux/io.h>
2415
2516 /**
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+ * read_poll_timeout - Periodically poll an address until a condition is
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+ * met or a timeout occurs
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+ * @op: accessor function (takes @args as its arguments)
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+ * @val: Variable to read the value into
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+ * @cond: Break condition (usually involving @val)
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+ * @sleep_us: Maximum time to sleep between reads in us (0
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+ * tight-loops). Should be less than ~20ms since usleep_range
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+ * is used (see Documentation/timers/timers-howto.rst).
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+ * @timeout_us: Timeout in us, 0 means never timeout
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+ * @sleep_before_read: if it is true, sleep @sleep_us before read.
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+ * @args: arguments for @op poll
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+ *
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+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
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+ * case, the last read value at @args is stored in @val. Must not
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+ * be called from atomic context if sleep_us or timeout_us are used.
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+ *
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+ * When available, you'll probably want to use one of the specialized
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+ * macros defined below rather than this macro directly.
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+ */
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+#define read_poll_timeout(op, val, cond, sleep_us, timeout_us, \
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+ sleep_before_read, args...) \
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+({ \
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+ u64 __timeout_us = (timeout_us); \
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+ unsigned long __sleep_us = (sleep_us); \
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+ ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
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+ might_sleep_if((__sleep_us) != 0); \
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+ if (sleep_before_read && __sleep_us) \
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+ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
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+ for (;;) { \
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+ (val) = op(args); \
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+ if (cond) \
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+ break; \
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+ if (__timeout_us && \
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+ ktime_compare(ktime_get(), __timeout) > 0) { \
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+ (val) = op(args); \
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+ break; \
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+ } \
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+ if (__sleep_us) \
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+ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
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+ cpu_relax(); \
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+ } \
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+ (cond) ? 0 : -ETIMEDOUT; \
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+})
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+
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+/**
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+ * read_poll_timeout_atomic - Periodically poll an address until a condition is
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+ * met or a timeout occurs
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+ * @op: accessor function (takes @args as its arguments)
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+ * @val: Variable to read the value into
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+ * @cond: Break condition (usually involving @val)
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+ * @delay_us: Time to udelay between reads in us (0 tight-loops). Should
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+ * be less than ~10us since udelay is used (see
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+ * Documentation/timers/timers-howto.rst).
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+ * @timeout_us: Timeout in us, 0 means never timeout
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+ * @delay_before_read: if it is true, delay @delay_us before read.
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+ * @args: arguments for @op poll
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+ *
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+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
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+ * case, the last read value at @args is stored in @val.
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+ *
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+ * When available, you'll probably want to use one of the specialized
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+ * macros defined below rather than this macro directly.
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+ */
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+#define read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, \
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+ delay_before_read, args...) \
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+({ \
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+ u64 __timeout_us = (timeout_us); \
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+ unsigned long __delay_us = (delay_us); \
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+ ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
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+ if (delay_before_read && __delay_us) \
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+ udelay(__delay_us); \
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+ for (;;) { \
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+ (val) = op(args); \
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+ if (cond) \
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+ break; \
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+ if (__timeout_us && \
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+ ktime_compare(ktime_get(), __timeout) > 0) { \
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+ (val) = op(args); \
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+ break; \
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+ } \
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+ if (__delay_us) \
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+ udelay(__delay_us); \
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+ cpu_relax(); \
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+ } \
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+ (cond) ? 0 : -ETIMEDOUT; \
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+})
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+
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+/**
26105 * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
27106 * @op: accessor function (takes @addr as its only argument)
28107 * @addr: Address to poll
....@@ -30,7 +109,7 @@
30109 * @cond: Break condition (usually involving @val)
31110 * @sleep_us: Maximum time to sleep between reads in us (0
32111 * tight-loops). Should be less than ~20ms since usleep_range
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- * is used (see Documentation/timers/timers-howto.txt).
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+ * is used (see Documentation/timers/timers-howto.rst).
34113 * @timeout_us: Timeout in us, 0 means never timeout
35114 *
36115 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
....@@ -41,25 +120,7 @@
41120 * macros defined below rather than this macro directly.
42121 */
43122 #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
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-({ \
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- u64 __timeout_us = (timeout_us); \
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- unsigned long __sleep_us = (sleep_us); \
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- ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
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- might_sleep_if((__sleep_us) != 0); \
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- for (;;) { \
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- (val) = op(addr); \
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- if (cond) \
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- break; \
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- if (__timeout_us && \
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- ktime_compare(ktime_get(), __timeout) > 0) { \
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- (val) = op(addr); \
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- break; \
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- } \
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- if (__sleep_us) \
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- usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
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- } \
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- (cond) ? 0 : -ETIMEDOUT; \
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-})
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+ read_poll_timeout(op, val, cond, sleep_us, timeout_us, false, addr)
63124
64125 /**
65126 * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs
....@@ -69,7 +130,7 @@
69130 * @cond: Break condition (usually involving @val)
70131 * @delay_us: Time to udelay between reads in us (0 tight-loops). Should
71132 * be less than ~10us since udelay is used (see
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- * Documentation/timers/timers-howto.txt).
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+ * Documentation/timers/timers-howto.rst).
73134 * @timeout_us: Timeout in us, 0 means never timeout
74135 *
75136 * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
....@@ -79,25 +140,7 @@
79140 * macros defined below rather than this macro directly.
80141 */
81142 #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \
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-({ \
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- u64 __timeout_us = (timeout_us); \
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- unsigned long __delay_us = (delay_us); \
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- ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
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- for (;;) { \
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- (val) = op(addr); \
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- if (cond) \
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- break; \
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- if (__timeout_us && \
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- ktime_compare(ktime_get(), __timeout) > 0) { \
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- (val) = op(addr); \
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- break; \
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- } \
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- if (__delay_us) \
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- udelay(__delay_us); \
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- } \
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- (cond) ? 0 : -ETIMEDOUT; \
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-})
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-
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+ read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, false, addr)
101144
102145 #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \
103146 readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us)