mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-21 12:19:08 +07:00
54c523127b
It is sometimes necessary to poll a memory-mapped register until its value satisfies some condition. Introduce a family of convenience macros that do this. Tight-looping, sleeping, and timing out can all be accomplished using these macros. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Robert Elliott <elliott@hp.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matt Wagantall <mattw@codeaurora.org> Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
145 lines
5.5 KiB
C
145 lines
5.5 KiB
C
/*
|
|
* 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 */
|