gem5/src/dev/arm/amba_fake.cc
Andreas Hansson 5df96cb690 mem: Remove redundant Packet::allocate calls
This patch cleans up the packet memory allocation confusion. The data
is always allocated at the requesting side, when a packet is created
(or copied), and there is never a need for any device to allocate any
space if it is merely responding to a paket. This behaviour is in line
with how SystemC and TLM works as well, thus increasing
interoperability, and matching established conventions.

The redundant calls to Packet::allocate are removed, and the checks in
the function are tightened up to make sure data is only ever allocated
once. There are still some oddities in the packet copy constructor
where we copy the data pointer if it is static (without ownership),
and allocate new space if the data is dynamic (with ownership). The
latter is being worked on further in a follow-on patch.
2014-12-02 06:07:41 -05:00

90 lines
3.1 KiB
C++

/*
* Copyright (c) 2010 ARM Limited
* 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) 2005 The Regents of The University of Michigan
* 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.
*
* Authors: Ali Saidi
*/
#include "base/trace.hh"
#include "debug/AMBA.hh"
#include "dev/arm/amba_fake.hh"
#include "mem/packet.hh"
#include "mem/packet_access.hh"
AmbaFake::AmbaFake(const Params *p)
: AmbaPioDevice(p, 0xfff)
{
}
Tick
AmbaFake::read(PacketPtr pkt)
{
assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
Addr daddr = pkt->getAddr() - pioAddr;
DPRINTF(AMBA, " read register %#x\n", daddr);
pkt->set<uint32_t>(0);
if (!readId(pkt, ambaId, pioAddr) && !params()->ignore_access)
panic("Tried to read AmbaFake at offset %#x that doesn't exist\n", daddr);
pkt->makeAtomicResponse();
return pioDelay;
}
Tick
AmbaFake::write(PacketPtr pkt)
{
Addr daddr = pkt->getAddr() - pioAddr;
if (!params()->ignore_access)
panic("Tried to write AmbaFake at offset %#x that doesn't exist\n", daddr);
pkt->makeAtomicResponse();
return pioDelay;
}
AmbaFake *
AmbaFakeParams::create()
{
return new AmbaFake(this);
}