/*-
 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
 * Copyright (c) 2015 Ruslan Bukin <br@bsdpad.com>
 * All rights reserved.
 *
 * Portions of this software were developed by SRI International and the
 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * Portions of this software were developed by the University of Cambridge
 * Computer Laboratory as part of the CTSRD Project, with support from the
 * UK Higher Education Innovation Fund (HEIF).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

/*
 * Machine-dependent thread prototypes/definitions.
 */
#ifndef _PTHREAD_MD_H_
#define	_PTHREAD_MD_H_

#include <sys/types.h>
#include <stddef.h>

#define	CPU_SPINWAIT
#define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
#define	TP_OFFSET		sizeof(struct tcb)

/*
 * Variant I tcb. The structure layout is fixed, don't blindly
 * change it!
 */
struct tcb {
	void			*tcb_dtv;
	struct pthread		*tcb_thread;
};

/* Called from the thread to set its private data. */
static __inline void
_tcb_set(struct tcb *tcb)
{

	__asm __volatile("mv tp, %0" :: "r"((uint8_t *)tcb + TP_OFFSET));
}

/*
 * Get the current tcb.
 */
static __inline struct tcb *
_tcb_get(void)
{
	register uint8_t *_tp;

	__asm __volatile("mv %0, tp" : "=r"(_tp));

	return ((struct tcb *)(_tp - TP_OFFSET));
}

extern struct pthread *_thr_initial;

static __inline struct pthread *
_get_curthread(void)
{

	if (_thr_initial)
		return (_tcb_get()->tcb_thread);
	return (NULL);
}

#endif /* _PTHREAD_MD_H_ */