/*      $OpenBSD: tcb.h,v 1.3 2016/10/02 20:11:32 guenther Exp $        */

/*
 * Copyright (c) 2011 Philip Guenther <guenther@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _MACHINE_TCB_H_
#define _MACHINE_TCB_H_

#ifdef _KERNEL

#include <machine/pcb.h>

static inline void
__arm_set_tcb(void *tcb)
{
        __asm volatile("mcr p15, 0, %0, c13, c0, 3\n" : : "r" (tcb));
}

#define TCB_GET(p)              \
        ((struct pcb *)(p)->p_addr)->pcb_tcb

#define TCB_SET(p, addr)        \
        do {                                                    \
                ((struct pcb *)(p)->p_addr)->pcb_tcb = (addr);  \
                __arm_set_tcb(addr);                            \
        } while (0)

#else /* _KERNEL */

/* ELF TLS ABI calls for small TCB, with static TLS data after it */
#define TLS_VARIANT     1

static inline void *
__arm_read_tcb(void)
{
        void *tcb;
        __asm volatile("mrc p15, 0, %0, c13, c0, 3\n" : "=r" (tcb));
        return tcb;
}

#define TCB_GET()               __arm_read_tcb()

#endif /* _KERNEL */

#endif /* _MACHINE_TCB_H_ */