1/* $NetBSD: lock_stubs.S,v 1.13 2008/05/25 15:56:12 chs Exp $ */ 2 3/* 4 * Copyright (c) 2007 Valeriy E. Ushakov 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30#include <sh3/asm.h> 31#include <sh3/psl.h> 32 33#include "opt_lockdebug.h" 34 35 36/* 37 * LINTSTUB: include <sys/types.h> 38 * LINTSTUB: include <sys/mutex.h> 39 */ 40 41 42/* 43 * LINTSTUB: Func: uintptr_t _lock_cas(volatile uintptr_t *ptr, uintptr_t old, uintptr_t new); 44 * 45 * Atomic compare-and-swap for kernel use. SuperH machines are 46 * uniprocessor, so we need to be atomic only w.r.t. interrupts. 47 * Implement this as (the only in-kernel) RAS, with restart check 48 * done on return from interrupt. 49 * 50 * Mutex stubs below depend on this function: 51 * r4 - preserved, passed along to mutex_vector_{enter,exit} 52 * r7 - preserved, used to save pr (to avoid touching stack) 53 * T - still reflects cas success status (to avoid another test) 54 */ 55ENTRY(_lock_cas) 56ALTENTRY(_lock_cas_ras_start) 57 mov.l @r4, r0 58 cmp/eq r0, r5 ! T = (*ptr == old) 59 bf 1f 60 mov.l r6, @r4 ! *ptr = new 61ALTENTRY(_lock_cas_ras_end) 621: rts 63 nop ! retval = *ptr at time of compare 64 SET_ENTRY_SIZE(_lock_cas) 65 66STRONG_ALIAS(_atomic_cas_ulong,_lock_cas) 67STRONG_ALIAS(atomic_cas_ulong,_lock_cas) 68STRONG_ALIAS(_atomic_cas_32,_lock_cas) 69STRONG_ALIAS(atomic_cas_32,_lock_cas) 70STRONG_ALIAS(_atomic_cas_uint,_lock_cas) 71STRONG_ALIAS(atomic_cas_uint,_lock_cas) 72STRONG_ALIAS(_atomic_cas_ptr,_lock_cas) 73STRONG_ALIAS(atomic_cas_ptr,_lock_cas) 74 75STRONG_ALIAS(_atomic_cas_ulong_ni,_lock_cas) 76STRONG_ALIAS(atomic_cas_ulong_ni,_lock_cas) 77STRONG_ALIAS(_atomic_cas_32_ni,_lock_cas) 78STRONG_ALIAS(atomic_cas_32_ni,_lock_cas) 79STRONG_ALIAS(_atomic_cas_uint_ni,_lock_cas) 80STRONG_ALIAS(atomic_cas_uint_ni,_lock_cas) 81STRONG_ALIAS(_atomic_cas_ptr_ni,_lock_cas) 82STRONG_ALIAS(atomic_cas_ptr_ni,_lock_cas) 83 84#if !defined(LOCKDEBUG) 85 86/* 87 * LINTSTUB: Func: void mutex_enter(kmutex_t *mtx); 88 */ 89ENTRY(mutex_enter) 90 sts pr, r7 ! depend on _lock_cas not clobbering r7 91 mov.l .L_curlwp, r6 92 mov #0, r5 93 bsr _lock_cas ! _lock_cas(&mtx->mtx_owner, 0, curlwp) 94 mov.l @r6, r6 95 !! T bit still indicates if cas was successful 96 bf.s 1f ! hard case if cas failed 97 lds r7, pr 98 rts 99 nop 100 101 !! depend on _lock_cas not clobbering mtx in r4 1021: mov.l .L_mutex_vector_enter, r0 103 jmp @r0 104 nop 105 /* NOTREACHED */ 106 107 108/* 109 * LINTSTUB: Func: void mutex_exit(kmutex_t *mtx); 110 */ 111ENTRY(mutex_exit) 112 sts pr, r7 ! depend on _lock_cas not clobbering r7 113 mov.l .L_curlwp, r5 114 mov #0, r6 115 bsr _lock_cas ! _lock_cas(&mtx->mtx_owner, curlwp, 0) 116 mov.l @r5, r5 117 !! T bit still indicates if cas was successful 118 bf.s 1f ! hard case if cas failed 119 lds r7, pr 120 rts 121 nop 122 123 !! depend on _lock_cas not clobbering mtx in r4 1241: mov.l .L_mutex_vector_exit, r0 125 jmp @r0 126 nop 127 /* NOTREACHED */ 128 129 .align 2 130.L_curlwp: .long _C_LABEL(curlwp) 131.L_mutex_vector_enter: .long _C_LABEL(mutex_vector_enter) 132.L_mutex_vector_exit: .long _C_LABEL(mutex_vector_exit) 133 134#endif /* !LOCKDEBUG */ 135