| /* 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); \ |
| } \ |
| (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); \ |
| } \ |
| (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 */ |