/*      $NetBSD: lock_stubs.S,v 1.15 2026/01/09 22:54:34 jmcneill Exp $ */

/*-
 * Copyright (c) 2007 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Andrew Doran.
 *
 * 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.
 */

#include <machine/asm.h>

#include "assym.h"

#ifdef _KERNEL_OPT
#include "opt_multiprocessor.h"
#include "opt_lockdebug.h"
#endif

#if defined(MULTIPROCESSOR)
#define ISYNC   isync
#define SYNC    sync
#else
#define ISYNC   /* nothing */
#define SYNC    /* nothing */
#endif

        .text

#if __HAVE_MUTEX_STUBS
/*
 * int _lock_cas(uintptr_t *ptr, uintptr_t old, uintptr_t new);
 */
ENTRY(_lock_cas)
1:
        lptrarx %r10,0,%r3
        cmpptr  %r10,%r4
        bne-    2f
        POWERPC_STWCX_PRE(0,%r3)
        stptrcx. %r5,0,%r3
        bne-    1b
        SYNC
        li      %r3,1
        blr
2:
        li      %r3,0
        blr

#if !defined(LOCKDEBUG)
/*
 * void mutex_enter(kmutex_t *);
 */
ENTRY(mutex_enter)
1:
        lptrarx %r10,0,%r3
        cmpptri %r10,0
        bne-    2f
        POWERPC_STWCX_PRE(0,%r3)
        stptrcx. %r13,0,%r3
        bne-    1b
        ISYNC
        blr
2:
        b       _C_LABEL(mutex_vector_enter)

/*
 * void mutex_exit(kmutex_t *);
 */
ENTRY(mutex_exit)
        SYNC
        li      %r7,0
1:
        lptrarx %r10,0,%r3
        cmpptr  %r10,%r13
        bne-    2f
        POWERPC_STWCX_PRE(0,%r3)
        stptrcx. %r7,0,%r3
        bne-    1b
        blr
2:
        b       _C_LABEL(mutex_vector_exit)

#endif  /* !LOCKDEBUG */

/*
 * void rw_enter(krwlock_t *krw, krw_t op);
 */
#if RW_READ_INCR != 32
#error RW_READ_INCR != 32, clrrXi need fixing
#endif
#if RW_OWNER != 0
#error RW_OWNER != 0, ldptr should be ldptru
#endif

#if __HAVE_RW_STUBS

ENTRY(rw_enter)
        cmpwi   %r3,RW_READER
        bne-    1f

        ldptr   %r9,RW_OWNER(%r3)
        clrrptri %r9,%r9,5              /* clear low 5 bits */
        addi    %r7,%r9,RW_READ_INCR
        b       2f
1:
        li      %r9,0
        ori     %r7,%r13,RW_WRITE_LOCKED

2:      lptrarx %r10,0,%r3
        cmpptr  %r10,%r9
        bne-    3f
        POWERPC_STWCX_PRE(0,%r3)
        stptrcx. %r7,0,%r3
        bne-    2b
        ISYNC
        blr

3:      b       _C_LABEL(rw_vector_enter)

/*
 * bool rw_tryenter(krwlock_t *krw, krw_t op);
 */
ENTRY(rw_tryenter)
        cmpwi   %r3,RW_READER
        bne-    1f

        ldptr   %r9,RW_OWNER(%r3)
        clrrptri %r9,%r9,5              /* clear low 5 bits */
        addi    %r7,%r9,RW_READ_INCR
        b       2f

1:      li      %r9,0
        ori     %r7,%r13,RW_WRITE_LOCKED

2:      lptrarx %r10,0,%r3
        cmpptr  %r10,%r9
        bne-    3f
        POWERPC_STWCX_PRE(0,%r3)
        stptrcx. %r7,0,%r3
        bne-    2b

        ISYNC
        li      %r3,1
        blr

3:      li      %r3,0
        blr

/*
 * void rw_exit(krwlock_t *krw, krw_t op);
 */
ENTRY(rw_exit)
        ldptr   %r9,RW_OWNER(%r3)
        SYNC
        andi.   %r0,%r9,RW_WRITE_LOCKED
        bne-    1f

        clrrptri. %r9,%r9,5             /* clear low 5 bits */
        beq-    3f                      /* if 0, no reader, go slow */

        addi    %r7,%r9,-RW_READ_INCR
        b       2f
1:
        li      %r7,0
        ori     %r9,%r13,RW_WRITE_LOCKED

2:      lptrarx %r10,0,%r3
        cmpptr  %r10,%r9
        bne-    3f
        POWERPC_STWCX_PRE(0,%r3)
        stptrcx. %r7,0,%r3
        bne-    2b

        blr

3:      b       _C_LABEL(rw_vector_exit)

#endif  /* __HAVE_RW_STUBS */

#endif  /* __HAVE_MUTEX_STUBS */