/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (c) 2019-2023, NVIDIA CORPORATION.  All rights reserved.
 */

#ifndef DCE_COND_H
#define DCE_COND_H

#include <linux/wait.h>
#include <linux/sched.h>

struct dce_cond {
	bool initialized;
	wait_queue_head_t wq;
};

/**
 * DCE_COND_WAIT - Wait for a condition to be true
 *
 * @c - The condition variable to sleep on
 * @condition - The condition that needs to be true
 *
 * Wait for a condition to become true.
 */
#define DCE_COND_WAIT(c, condition) \
({\
	int ret = 0; \
	wait_event((c)->wq, condition); \
	ret;\
})

/**
 * DCE_COND_WAIT_INTERRUPTIBLE - Wait for a condition to be true
 *
 * @c - The condition variable to sleep on
 * @condition - The condition that needs to be true
 *
 * Wait for a condition to become true. Returns -ERESTARTSYS
 * on signal.
 */
#define DCE_COND_WAIT_INTERRUPTIBLE(c, condition) \
({ \
	int ret = 0; \
	ret = wait_event_interruptible((c)->wq, condition); \
	ret; \
})

/**
 * DCE_COND_WAIT_TIMEOUT - Wait for a condition to be true
 *
 * @c - The condition variable to sleep on
 * @condition - The condition that needs to be true
 * @timeout_ms - Timeout in milliseconds, or 0 for infinite wait.
 *               This parameter must be a u32. Since this is a macro, this is
 *               enforced by assigning a typecast NULL pointer to a u32 tmp
 *               variable which will generate a compiler warning (or error if
 *               the warning is configured as an error).
 *
 * Wait for a condition to become true. Returns -ETIMEOUT if
 * the wait timed out with condition false.
 */
#define DCE_COND_WAIT_TIMEOUT(c, condition, timeout_ms) \
({\
	int ret = 0; \
	/* This is the assignment to enforce a u32 for timeout_ms */ \
	u32 *tmp = (typeof(timeout_ms) *)NULL; \
	(void)tmp; \
	if (timeout_ms > 0U) { \
		long _ret = wait_event_timeout((c)->wq, condition, \
						msecs_to_jiffies(timeout_ms)); \
		if (_ret == 0) \
			ret = -ETIMEDOUT; \
	} else { \
		wait_event((c)->wq, condition); \
	} \
	ret;\
})

/**
 * DCE_COND_WAIT_INTERRUPTIBLE_TIMEOUT - Wait for a condition to be true
 *
 * @c - The condition variable to sleep on
 * @condition - The condition that needs to be true
 * @timeout_ms - Timeout in milliseconds, or 0 for infinite wait.
 *               This parameter must be a u32. Since this is a macro, this is
 *               enforced by assigning a typecast NULL pointer to a u32 tmp
 *               variable which will generate a compiler warning (or error if
 *               the warning is configured as an error).
 *
 * Wait for a condition to become true. Returns -ETIMEOUT if
 * the wait timed out with condition false or -ERESTARTSYS on
 * signal.
 */
#define DCE_COND_WAIT_INTERRUPTIBLE_TIMEOUT(c, condition, timeout_ms) \
({ \
	int ret = 0; \
	/* This is the assignment to enforce a u32 for timeout_ms */ \
	u32 *tmp = (typeof(timeout_ms) *)NULL; \
	(void)tmp; \
	if (timeout_ms > 0U) { \
		long _ret = wait_event_interruptible_timeout((c)->wq, \
				condition, msecs_to_jiffies(timeout_ms)); \
		if (_ret == 0) \
			ret = -ETIMEDOUT; \
		else if (_ret == -ERESTARTSYS) \
			ret = -ERESTARTSYS; \
	} else { \
		ret = wait_event_interruptible((c)->wq, condition); \
	} \
	ret; \
})

int dce_cond_init(struct dce_cond *cond);

void dce_cond_signal(struct dce_cond *cond);

void dce_cond_signal_interruptible(struct dce_cond *cond);

int dce_cond_broadcast(struct dce_cond *cond);

int dce_cond_broadcast_interruptible(struct dce_cond *cond);

void dce_cond_destroy(struct dce_cond *cond);

#endif