/* $NetBSD: lwp_private.h,v 1.1 2024/11/30 01:04:13 christos Exp $ */

/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _RISCV_LWP_PRIVATE_H_
#define _RISCV_LWP_PRIVATE_H_

#include <sys/cdefs.h>
#include <sys/tls.h>

/*
* On RISCV, since displacements are signed 12-bit values, the TCB Pointer
* is biased by sizeof(tcb) so that first thread datum can be addressed by
* -sizeof(tcb).
*/

#define TLS_TP_OFFSET   0x0
#define TLS_TCB_ALIGN   16
#define TLS_DTV_OFFSET  0x800
__CTASSERT(TLS_TP_OFFSET + sizeof(struct tls_tcb) < 0x800);

__BEGIN_DECLS

static __inline void *
__lwp_getprivate_fast(void)
{
       void *__tp;
       __asm("mv %0, tp" : "=r"(__tp));
       return __tp;
}

static __inline void *
__lwp_gettcb_fast(void)
{
       void *__tcb;

       __asm __volatile(
               "addi %[__tcb], tp, %[__offset]"
           :   [__tcb] "=r" (__tcb)
           :   [__offset] "n" (-(TLS_TP_OFFSET + sizeof(struct tls_tcb))));

       return __tcb;
}

static __inline void
__lwp_settcb(void *__tcb)
{
       __asm __volatile(
               "addi tp, %[__tcb], %[__offset]"
           :
           :   [__tcb] "r" (__tcb),
               [__offset] "n" (TLS_TP_OFFSET + sizeof(struct tls_tcb)));
}

__END_DECLS

#endif /* !_RISCV_LWP_PRIVATE_H_ */