1/* $NetBSD: mutex.h,v 1.6 2023/07/12 12:50:13 riastradh Exp $ */ 2 3/*- 4 * Copyright (c) 2002, 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe and Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#ifndef _RISCV_MUTEX_H_ 33#define _RISCV_MUTEX_H_ 34 35#include <sys/types.h> 36 37#ifndef __MUTEX_PRIVATE 38 39struct kmutex { 40 uintptr_t mtx_pad1; 41}; 42 43#else /* __MUTEX_PRIVATE */ 44 45#include <sys/cdefs.h> 46 47#include <sys/param.h> 48 49#include <machine/intr.h> 50 51struct kmutex { 52 volatile uintptr_t mtx_owner; 53}; 54 55#ifdef _LP64 56#define MTX_ASMOP_SFX ".d" // doubleword atomic op 57#else 58#define MTX_ASMOP_SFX ".w" // word atomic op 59#endif 60 61#define MTX_LOCK __BIT(8) // just one bit 62#define MTX_IPL __BITS(7,4) // only need 4 bits 63 64#undef MUTEX_SPIN_IPL // override <sys/mutex.h> 65#define MUTEX_SPIN_IPL(a) riscv_mutex_spin_ipl(a) 66#define MUTEX_INITIALIZE_SPIN_IPL(a,b) riscv_mutex_initialize_spin_ipl(a,b) 67#define MUTEX_SPINBIT_LOCK_INIT(a) riscv_mutex_spinbit_lock_init(a) 68#define MUTEX_SPINBIT_LOCK_TRY(a) riscv_mutex_spinbit_lock_try(a) 69#define MUTEX_SPINBIT_LOCKED_P(a) riscv_mutex_spinbit_locked_p(a) 70#define MUTEX_SPINBIT_LOCK_UNLOCK(a) riscv_mutex_spinbit_lock_unlock(a) 71 72static inline ipl_cookie_t 73riscv_mutex_spin_ipl(kmutex_t *__mtx) 74{ 75 return (ipl_cookie_t){._spl = __SHIFTOUT(__mtx->mtx_owner, MTX_IPL)}; 76} 77 78static inline void 79riscv_mutex_initialize_spin_ipl(kmutex_t *__mtx, int ipl) 80{ 81 __mtx->mtx_owner = (__mtx->mtx_owner & ~MTX_IPL) 82 | __SHIFTIN(ipl, MTX_IPL); 83} 84 85static inline void 86riscv_mutex_spinbit_lock_init(kmutex_t *__mtx) 87{ 88 __mtx->mtx_owner &= ~MTX_LOCK; 89} 90 91static inline bool 92riscv_mutex_spinbit_locked_p(const kmutex_t *__mtx) 93{ 94 return (__mtx->mtx_owner & MTX_LOCK) != 0; 95} 96 97static inline bool 98riscv_mutex_spinbit_lock_try(kmutex_t *__mtx) 99{ 100 uintptr_t __old; 101 __asm __volatile( 102 "amoor" MTX_ASMOP_SFX ".aq\t%0, %1, (%2)" 103 : "=r"(__old) 104 : "r"(MTX_LOCK), "r"(__mtx)); 105 return (__old & MTX_LOCK) == 0; 106} 107 108static inline void 109riscv_mutex_spinbit_lock_unlock(kmutex_t *__mtx) 110{ 111 __asm __volatile( 112 "amoand" MTX_ASMOP_SFX ".rl\tx0, %0, (%1)" 113 :: "r"(~MTX_LOCK), "r"(__mtx)); 114} 115 116#if 0 117#define __HAVE_MUTEX_STUBS 1 118#define __HAVE_SPIN_MUTEX_STUBS 1 119#endif 120#define __HAVE_SIMPLE_MUTEXES 1 121 122#endif /* __MUTEX_PRIVATE */ 123 124#endif /* _RISCV_MUTEX_H_ */ 125