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/*
* Copyright (c) 2010,2019 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.
*
* 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.
*/
#include "dev/arm/a9scu.hh"
#include "base/intmath.hh"
#include "base/trace.hh"
#include "mem/packet.hh"
#include "mem/packet_access.hh"
#include "sim/system.hh"
A9SCU::A9SCU(const Params &p)
: BasicPioDevice(p, 0x60)
{
}
Tick
A9SCU::read(PacketPtr pkt)
{
assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
assert(pkt->getSize() == 4);
Addr daddr = pkt->getAddr() - pioAddr;
switch(daddr) {
case Control:
pkt->setLE(1); // SCU already enabled
break;
case Config:
{
/* Without making a completely new SCU, we can use the core count
* field as 4 bits and inform the OS of up to 16 CPUs. Although
* the core count is technically bits [1:0] only, bits [3:2] are
* SBZ for future expansion like this.
*/
int threads = sys->threads.size();
if (threads > 4) {
warn_once("A9SCU with >4 CPUs is unsupported");
fatal_if(threads > 15,
"Too many CPUs (%d) for A9SCU!", threads);
}
int smp_bits, core_cnt;
smp_bits = (1 << threads) - 1;
core_cnt = threads - 1;
pkt->setLE(smp_bits << 4 | core_cnt);
}
break;
default:
// Only configuration register is implemented
panic("Tried to read SCU at offset %#x\n", daddr);
break;
}
pkt->makeAtomicResponse();
return pioDelay;
}
Tick
A9SCU::write(PacketPtr pkt)
{
assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
Addr daddr = pkt->getAddr() - pioAddr;
switch (daddr) {
default:
// Nothing implemented at this point
warn("Tried to write SCU at offset %#x\n", daddr);
break;
}
pkt->makeAtomicResponse();
return pioDelay;
}