| /* |
| * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 and |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #ifndef _LINUX_IOPOLL_H |
| #define _LINUX_IOPOLL_H |
| |
| #include <linux/kernel.h> |
| #include <linux/types.h> |
| #include <linux/hrtimer.h> |
| #include <linux/delay.h> |
| #include <linux/errno.h> |
| #include <linux/io.h> |
| |
| /** |
| * 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.txt). |
| * @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) \ |
| ({ \ |
| ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \ |
| might_sleep_if(sleep_us); \ |
| for (;;) { \ |
| (val) = op(addr); \ |
| if (cond) \ |
| break; \ |
| if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \ |
| (val) = op(addr); \ |
| break; \ |
| } \ |
| if (sleep_us) \ |
| usleep_range((sleep_us >> 2) + 1, sleep_us); \ |
| } \ |
| (cond) ? 0 : -ETIMEDOUT; \ |
| }) |
| |
| /** |
| * 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.txt). |
| * @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) \ |
| ({ \ |
| ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \ |
| for (;;) { \ |
| (val) = op(addr); \ |
| if (cond) \ |
| break; \ |
| if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \ |
| (val) = op(addr); \ |
| break; \ |
| } \ |
| if (delay_us) \ |
| udelay(delay_us); \ |
| } \ |
| (cond) ? 0 : -ETIMEDOUT; \ |
| }) |
| |
| |
| #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 */ |