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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
- */
- #ifndef _LINUX_IOPOLL_H
- #define _LINUX_IOPOLL_H
- #include <linux/kernel.h>
- #include <linux/types.h>
- #include <linux/ktime.h>
- #include <linux/delay.h>
- #include <linux/errno.h>
- #include <linux/io.h>
- /**
- * read_poll_timeout - Periodically poll an address until a condition is
- * met or a timeout occurs
- * @op: accessor function (takes @args as its arguments)
- * @val: Variable to read the value into
- * @cond: Break condition (usually involving @val)
- * @sleep_us: Maximum time to sleep between reads in us (0
- * tight-loops). Should be less than ~20ms since usleep_range
- * is used (see Documentation/timers/timers-howto.rst).
- * @timeout_us: Timeout in us, 0 means never timeout
- * @sleep_before_read: if it is true, sleep @sleep_us before read.
- * @args: arguments for @op poll
- *
- * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
- * case, the last read value at @args is stored in @val. Must not
- * be called from atomic context if sleep_us or timeout_us are used.
- *
- * When available, you'll probably want to use one of the specialized
- * macros defined below rather than this macro directly.
- */
- #define read_poll_timeout(op, val, cond, sleep_us, timeout_us, \
- sleep_before_read, args...) \
- ({ \
- u64 __timeout_us = (timeout_us); \
- unsigned long __sleep_us = (sleep_us); \
- ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
- might_sleep_if((__sleep_us) != 0); \
- if (sleep_before_read && __sleep_us) \
- usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
- for (;;) { \
- (val) = op(args); \
- if (cond) \
- break; \
- if (__timeout_us && \
- ktime_compare(ktime_get(), __timeout) > 0) { \
- (val) = op(args); \
- break; \
- } \
- if (__sleep_us) \
- usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
- cpu_relax(); \
- } \
- (cond) ? 0 : -ETIMEDOUT; \
- })
- /**
- * read_poll_timeout_atomic - Periodically poll an address until a condition is
- * met or a timeout occurs
- * @op: accessor function (takes @args as its arguments)
- * @val: Variable to read the value into
- * @cond: Break condition (usually involving @val)
- * @delay_us: Time to udelay between reads in us (0 tight-loops). Should
- * be less than ~10us since udelay is used (see
- * Documentation/timers/timers-howto.rst).
- * @timeout_us: Timeout in us, 0 means never timeout
- * @delay_before_read: if it is true, delay @delay_us before read.
- * @args: arguments for @op poll
- *
- * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
- * case, the last read value at @args is stored in @val.
- *
- * When available, you'll probably want to use one of the specialized
- * macros defined below rather than this macro directly.
- */
- #define read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, \
- delay_before_read, args...) \
- ({ \
- u64 __timeout_us = (timeout_us); \
- unsigned long __delay_us = (delay_us); \
- ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
- if (delay_before_read && __delay_us) \
- udelay(__delay_us); \
- for (;;) { \
- (val) = op(args); \
- if (cond) \
- break; \
- if (__timeout_us && \
- ktime_compare(ktime_get(), __timeout) > 0) { \
- (val) = op(args); \
- break; \
- } \
- if (__delay_us) \
- udelay(__delay_us); \
- cpu_relax(); \
- } \
- (cond) ? 0 : -ETIMEDOUT; \
- })
- /**
- * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
- * @op: accessor function (takes @addr as its only argument)
- * @addr: Address to poll
- * @val: Variable to read the value into
- * @cond: Break condition (usually involving @val)
- * @sleep_us: Maximum time to sleep between reads in us (0
- * tight-loops). Should be less than ~20ms since usleep_range
- * is used (see Documentation/timers/timers-howto.rst).
- * @timeout_us: Timeout in us, 0 means never timeout
- *
- * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
- * case, the last read value at @addr is stored in @val. Must not
- * be called from atomic context if sleep_us or timeout_us are used.
- *
- * When available, you'll probably want to use one of the specialized
- * macros defined below rather than this macro directly.
- */
- #define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
- read_poll_timeout(op, val, cond, sleep_us, timeout_us, false, addr)
- /**
- * readx_poll_timeout_atomic - Periodically poll an address until a condition is met or a timeout occurs
- * @op: accessor function (takes @addr as its only argument)
- * @addr: Address to poll
- * @val: Variable to read the value into
- * @cond: Break condition (usually involving @val)
- * @delay_us: Time to udelay between reads in us (0 tight-loops). Should
- * be less than ~10us since udelay is used (see
- * Documentation/timers/timers-howto.rst).
- * @timeout_us: Timeout in us, 0 means never timeout
- *
- * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
- * case, the last read value at @addr is stored in @val.
- *
- * When available, you'll probably want to use one of the specialized
- * macros defined below rather than this macro directly.
- */
- #define readx_poll_timeout_atomic(op, addr, val, cond, delay_us, timeout_us) \
- read_poll_timeout_atomic(op, val, cond, delay_us, timeout_us, false, addr)
- #define readb_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readb, addr, val, cond, delay_us, timeout_us)
- #define readb_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readb, addr, val, cond, delay_us, timeout_us)
- #define readw_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readw, addr, val, cond, delay_us, timeout_us)
- #define readw_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readw, addr, val, cond, delay_us, timeout_us)
- #define readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readl, addr, val, cond, delay_us, timeout_us)
- #define readl_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readl, addr, val, cond, delay_us, timeout_us)
- #define readq_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readq, addr, val, cond, delay_us, timeout_us)
- #define readq_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readq, addr, val, cond, delay_us, timeout_us)
- #define readb_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readb_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readb_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readb_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readw_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readw_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readw_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readw_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readl_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readl_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readq_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout(readq_relaxed, addr, val, cond, delay_us, timeout_us)
- #define readq_relaxed_poll_timeout_atomic(addr, val, cond, delay_us, timeout_us) \
- readx_poll_timeout_atomic(readq_relaxed, addr, val, cond, delay_us, timeout_us)
- #endif /* _LINUX_IOPOLL_H */
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