locked_mem.hh revision 10030:b531e328342d
1/* 2 * Copyright (c) 2012 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2006-2007 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Steve Reinhardt 41 */ 42 43#ifndef __ARCH_MIPS_LOCKED_MEM_HH__ 44#define __ARCH_MIPS_LOCKED_MEM_HH__ 45 46/** 47 * @file 48 * 49 * ISA-specific helper functions for locked memory accesses. 50 */ 51 52#include "arch/registers.hh" 53#include "base/misc.hh" 54#include "base/trace.hh" 55#include "debug/LLSC.hh" 56#include "mem/packet.hh" 57#include "mem/request.hh" 58 59namespace MipsISA 60{ 61template <class XC> 62inline void 63handleLockedSnoop(XC *xc, PacketPtr pkt, Addr cacheBlockMask) 64{ 65 if (!xc->readMiscReg(MISCREG_LLFLAG)) 66 return; 67 68 Addr locked_addr = xc->readMiscReg(MISCREG_LLADDR) & cacheBlockMask; 69 Addr snoop_addr = pkt->getAddr(); 70 71 assert((cacheBlockMask & snoop_addr) == snoop_addr); 72 73 if (locked_addr == snoop_addr) 74 xc->setMiscReg(MISCREG_LLFLAG, false); 75} 76 77 78template <class XC> 79inline void 80handleLockedRead(XC *xc, Request *req) 81{ 82 xc->setMiscReg(MISCREG_LLADDR, req->getPaddr() & ~0xf); 83 xc->setMiscReg(MISCREG_LLFLAG, true); 84 DPRINTF(LLSC, "[tid:%i]: Load-Link Flag Set & Load-Link" 85 " Address set to %x.\n", 86 req->threadId(), req->getPaddr() & ~0xf); 87} 88 89template <class XC> 90inline void 91handleLockedSnoopHit(XC *xc) 92{ 93} 94 95template <class XC> 96inline bool 97handleLockedWrite(XC *xc, Request *req, Addr cacheBlockMask) 98{ 99 if (req->isUncacheable()) { 100 // Funky Turbolaser mailbox access...don't update 101 // result register (see stq_c in decoder.isa) 102 req->setExtraData(2); 103 } else { 104 // standard store conditional 105 bool lock_flag = xc->readMiscReg(MISCREG_LLFLAG); 106 Addr lock_addr = xc->readMiscReg(MISCREG_LLADDR); 107 108 if (!lock_flag || (req->getPaddr() & ~0xf) != lock_addr) { 109 // Lock flag not set or addr mismatch in CPU; 110 // don't even bother sending to memory system 111 req->setExtraData(0); 112 xc->setMiscReg(MISCREG_LLFLAG, false); 113 114 // the rest of this code is not architectural; 115 // it's just a debugging aid to help detect 116 // livelock by warning on long sequences of failed 117 // store conditionals 118 int stCondFailures = xc->readStCondFailures(); 119 stCondFailures++; 120 xc->setStCondFailures(stCondFailures); 121 if (stCondFailures % 100000 == 0) { 122 warn("%i: context %d: %d consecutive " 123 "store conditional failures\n", 124 curTick(), xc->contextId(), stCondFailures); 125 } 126 127 if (!lock_flag){ 128 DPRINTF(LLSC, "[tid:%i]: Lock Flag Set, " 129 "Store Conditional Failed.\n", 130 req->threadId()); 131 } else if ((req->getPaddr() & ~0xf) != lock_addr) { 132 DPRINTF(LLSC, "[tid:%i]: Load-Link Address Mismatch, " 133 "Store Conditional Failed.\n", 134 req->threadId()); 135 } 136 // store conditional failed already, so don't issue it to mem 137 return false; 138 } 139 } 140 141 return true; 142} 143 144} // namespace MipsISA 145 146#endif 147