| /* |
| * Copyright (c) 2006 The Regents of The University of Michigan |
| * Copyright (c) 2007-2008 The Florida State University |
| * Copyright (c) 2009 The University of Edinburgh |
| * Copyright (c) 2012 ARM Limited |
| * Copyright (c) 2014-2015 Sven Karlsson |
| * All rights reserved. |
| * |
| * The license below extends only to copyright in the software and shall |
| * not be construed as granting a license to any other intellectual |
| * property including but not limited to intellectual property relating |
| * to a hardware implementation of the functionality of the software |
| * licensed hereunder. You may use the software subject to the license |
| * terms below provided that you ensure that this notice is replicated |
| * unmodified and in its entirety in all distributions of the software, |
| * modified or unmodified, in source code or in binary form. |
| * |
| * Copyright (c) 2006-2007 The Regents of The University of Michigan |
| * Copyright (c) 2016 The University of Virginia |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * 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; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT |
| * OWNER 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 __ARCH_RISCV_LOCKED_MEM_HH__ |
| #define __ARCH_RISCV_LOCKED_MEM_HH__ |
| |
| #include <stack> |
| #include <unordered_map> |
| |
| #include "base/logging.hh" |
| #include "base/trace.hh" |
| #include "cpu/base.hh" |
| #include "debug/LLSC.hh" |
| #include "mem/packet.hh" |
| #include "mem/request.hh" |
| |
| /* |
| * ISA-specific helper functions for locked memory accesses. |
| */ |
| namespace RiscvISA |
| { |
| |
| const int WARN_FAILURE = 10000; |
| |
| // RISC-V allows multiple locks per hart, but each SC has to unlock the most |
| // recent one, so we use a stack here. |
| extern std::unordered_map<int, std::stack<Addr>> locked_addrs; |
| |
| template <class XC> inline void |
| handleLockedSnoop(XC *xc, PacketPtr pkt, Addr cacheBlockMask) |
| { |
| std::stack<Addr>& locked_addr_stack = locked_addrs[xc->contextId()]; |
| |
| if (locked_addr_stack.empty()) |
| return; |
| Addr snoop_addr = pkt->getAddr() & cacheBlockMask; |
| DPRINTF(LLSC, "Locked snoop on address %x.\n", snoop_addr); |
| if ((locked_addr_stack.top() & cacheBlockMask) == snoop_addr) |
| locked_addr_stack.pop(); |
| } |
| |
| |
| template <class XC> inline void |
| handleLockedRead(XC *xc, const RequestPtr &req) |
| { |
| std::stack<Addr>& locked_addr_stack = locked_addrs[xc->contextId()]; |
| |
| locked_addr_stack.push(req->getPaddr() & ~0xF); |
| DPRINTF(LLSC, "[cid:%d]: Reserved address %x.\n", |
| req->contextId(), req->getPaddr() & ~0xF); |
| } |
| |
| template <class XC> inline void |
| handleLockedSnoopHit(XC *xc) |
| {} |
| |
| template <class XC> inline bool |
| handleLockedWrite(XC *xc, const RequestPtr &req, Addr cacheBlockMask) |
| { |
| std::stack<Addr>& locked_addr_stack = locked_addrs[xc->contextId()]; |
| |
| // Normally RISC-V uses zero to indicate success and nonzero to indicate |
| // failure (right now only 1 is reserved), but in gem5 zero indicates |
| // failure and one indicates success, so here we conform to that (it should |
| // be switched in the instruction's implementation) |
| |
| DPRINTF(LLSC, "[cid:%d]: locked_addrs empty? %s.\n", req->contextId(), |
| locked_addr_stack.empty() ? "yes" : "no"); |
| if (!locked_addr_stack.empty()) { |
| DPRINTF(LLSC, "[cid:%d]: addr = %x.\n", req->contextId(), |
| req->getPaddr() & ~0xF); |
| DPRINTF(LLSC, "[cid:%d]: last locked addr = %x.\n", req->contextId(), |
| locked_addr_stack.top()); |
| } |
| if (locked_addr_stack.empty() |
| || locked_addr_stack.top() != ((req->getPaddr() & ~0xF))) { |
| req->setExtraData(0); |
| int stCondFailures = xc->readStCondFailures(); |
| xc->setStCondFailures(++stCondFailures); |
| if (stCondFailures % WARN_FAILURE == 0) { |
| warn("%i: context %d: %d consecutive SC failures.\n", |
| curTick(), xc->contextId(), stCondFailures); |
| } |
| return false; |
| } |
| if (req->isUncacheable()) { |
| req->setExtraData(2); |
| } |
| return true; |
| } |
| |
| template <class XC> |
| inline void |
| globalClearExclusive(XC *xc) |
| { |
| xc->getCpuPtr()->wakeup(xc->threadId()); |
| } |
| |
| } // namespace RiscvISA |
| |
| #endif // __ARCH_RISCV_LOCKED_MEM_HH__ |