src/dev/riscv/clint.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2021 Huawei International
  * 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/riscv/clint.hh"

 #include "cpu/base.hh"
 #include "debug/Clint.hh"
 #include "mem/packet.hh"
 #include "mem/packet_access.hh"
 #include "params/Clint.hh"
 #include "sim/system.hh"

 namespace gem5
 {

 using namespace RiscvISA;

 Clint::Clint(const Params &params) :
     BasicPioDevice(params, params.pio_size),
     system(params.system),
     nThread(params.num_threads),
     signal(params.name + ".signal", 0, this),
     registers(params.name + ".registers", params.pio_addr, this)
 {
 }

 void
 Clint::raiseInterruptPin(int id)
 {
     // Increment mtime
     uint64_t& mtime = registers.mtime.get();
     mtime++;

     for (int context_id = 0; context_id < nThread; context_id++) {

         auto tc = system->threads[context_id];

         // Update misc reg file
         ISA* isa = dynamic_cast<ISA*>(tc->getIsaPtr());
         isa->setMiscRegNoEffect(MISCREG_TIME, mtime);

         // Post timer interrupt
         uint64_t mtimecmp = registers.mtimecmp[context_id].get();
         if (mtime >= mtimecmp) {
             if (mtime == mtimecmp) {
                 DPRINTF(Clint,
                     "MTIP posted - thread: %d, mtime: %d, mtimecmp: %d\n",
                     context_id, mtime, mtimecmp);
             }
             tc->getCpuPtr()->postInterrupt(tc->threadId(),
                     ExceptionCode::INT_TIMER_MACHINE, 0);
         } else {
             tc->getCpuPtr()->clearInterrupt(tc->threadId(),
                     ExceptionCode::INT_TIMER_MACHINE, 0);
         }
     }
 }

 void
 Clint::ClintRegisters::init()
 {
     using namespace std::placeholders;

     // Calculate reserved space size
     const size_t reserved0_size = mtimecmpStart - clint->nThread * 4;
     reserved.emplace_back("reserved0", reserved0_size);
     const size_t reserved1_size = mtimeStart
         - mtimecmpStart - clint->nThread * 8;
     reserved.emplace_back("reserved1", reserved1_size);

     // Sanity check
     assert((int) clint->pioSize <= maxBankSize);

     // Initialize registers
     for (int i = 0; i < clint->nThread; i++) {
         msip.emplace_back(std::string("msip") + std::to_string(i), 0);
         mtimecmp.emplace_back(std::string("mtimecmp") + std::to_string(i), 0);
     }

     // Add registers to bank
     for (int i = 0; i < clint->nThread; i++) {
         auto read_cb = std::bind(&Clint::readMSIP, clint, _1, i);
         msip[i].reader(read_cb);
         auto write_cb = std::bind(&Clint::writeMSIP, clint, _1, _2, i);
         msip[i].writer(write_cb);
         addRegister(msip[i]);
     }
     addRegister(reserved[0]);
     for (int i = 0; i < clint->nThread; i++) {
         addRegister(mtimecmp[i]);
     }
     addRegister(reserved[1]);
     mtime.readonly();
     addRegister(mtime);
 }

 uint32_t
 Clint::readMSIP(Register32& reg, const int thread_id)
 {
     // To avoid discrepancies if mip is externally set using remote_gdb etc.
     auto tc = system->threads[thread_id];
     RegVal mip = tc->readMiscReg(MISCREG_IP);
     uint32_t msip = bits<uint32_t>(mip, ExceptionCode::INT_SOFTWARE_MACHINE);
     reg.update(msip);
     return reg.get();
 };

 void
 Clint::writeMSIP(Register32& reg, const uint32_t& data, const int thread_id)
 {
     reg.update(data);
     assert(data <= 1);
     auto tc = system->threads[thread_id];
     if (data > 0) {
         DPRINTF(Clint, "MSIP posted - thread: %d\n", thread_id);
         tc->getCpuPtr()->postInterrupt(tc->threadId(),
             ExceptionCode::INT_SOFTWARE_MACHINE, 0);
     } else {
         DPRINTF(Clint, "MSIP cleared - thread: %d\n", thread_id);
         tc->getCpuPtr()->clearInterrupt(tc->threadId(),
             ExceptionCode::INT_SOFTWARE_MACHINE, 0);
     }
 };

 Tick
 Clint::read(PacketPtr pkt)
 {
     // Check for atomic operation
     bool is_atomic = pkt->isAtomicOp() && pkt->cmd == MemCmd::SwapReq;
     DPRINTF(Clint,
         "Read request - addr: %#x, size: %#x, atomic:%d\n",
         pkt->getAddr(), pkt->getSize(), is_atomic);

     // Perform register read
     registers.read(pkt->getAddr(), pkt->getPtr<void>(), pkt->getSize());

     if (is_atomic) {
         // Perform atomic operation
         (*(pkt->getAtomicOp()))(pkt->getPtr<uint8_t>());
         return write(pkt);
     } else {
         pkt->makeResponse();
         return pioDelay;
     }
 }

 Tick
 Clint::write(PacketPtr pkt)
 {
     DPRINTF(Clint,
         "Write request - addr: %#x, size: %#x\n",
         pkt->getAddr(), pkt->getSize());

     // Perform register write
     registers.write(pkt->getAddr(), pkt->getPtr<void>(), pkt->getSize());

     pkt->makeResponse();
     return pioDelay;
 }

 void
 Clint::init()
 {
     registers.init();
     BasicPioDevice::init();
 }

 Port &
 Clint::getPort(const std::string &if_name, PortID idx)
 {
     if (if_name == "int_pin")
         return signal;
     else
         return BasicPioDevice::getPort(if_name, idx);
 }

 void
 Clint::serialize(CheckpointOut &cp) const
 {
     for (auto const &reg: registers.msip) {
         paramOut(cp, reg.name(), reg);
     }
     for (auto const &reg: registers.mtimecmp) {
         paramOut(cp, reg.name(), reg);
     }
     paramOut(cp, "mtime", registers.mtime);
 }

 void
 Clint::unserialize(CheckpointIn &cp)
 {
     for (auto &reg: registers.msip) {
         paramIn(cp, reg.name(), reg);
     }
     for (auto &reg: registers.mtimecmp) {
         paramIn(cp, reg.name(), reg);
     }
     paramIn(cp, "mtime", registers.mtime);
 }

 } // namespace gem5
	/*
	* Copyright (c) 2021 Huawei International
	* 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/riscv/clint.hh"

	#include "cpu/base.hh"
	#include "debug/Clint.hh"
	#include "mem/packet.hh"
	#include "mem/packet_access.hh"
	#include "params/Clint.hh"
	#include "sim/system.hh"

	namespace gem5
	{

	using namespace RiscvISA;

	Clint::Clint(const Params &params) :
	BasicPioDevice(params, params.pio_size),
	system(params.system),
	nThread(params.num_threads),
	signal(params.name + ".signal", 0, this),
	registers(params.name + ".registers", params.pio_addr, this)
	{
	}

	void
	Clint::raiseInterruptPin(int id)
	{
	// Increment mtime
	uint64_t& mtime = registers.mtime.get();
	mtime++;

	for (int context_id = 0; context_id < nThread; context_id++) {

	auto tc = system->threads[context_id];

	// Update misc reg file
	ISA* isa = dynamic_cast<ISA*>(tc->getIsaPtr());
	isa->setMiscRegNoEffect(MISCREG_TIME, mtime);

	// Post timer interrupt
	uint64_t mtimecmp = registers.mtimecmp[context_id].get();
	if (mtime >= mtimecmp) {
	if (mtime == mtimecmp) {
	DPRINTF(Clint,
	"MTIP posted - thread: %d, mtime: %d, mtimecmp: %d\n",
	context_id, mtime, mtimecmp);
	}
	tc->getCpuPtr()->postInterrupt(tc->threadId(),
	ExceptionCode::INT_TIMER_MACHINE, 0);
	} else {
	tc->getCpuPtr()->clearInterrupt(tc->threadId(),
	ExceptionCode::INT_TIMER_MACHINE, 0);
	}
	}
	}

	void
	Clint::ClintRegisters::init()
	{
	using namespace std::placeholders;

	// Calculate reserved space size
	const size_t reserved0_size = mtimecmpStart - clint->nThread * 4;
	reserved.emplace_back("reserved0", reserved0_size);
	const size_t reserved1_size = mtimeStart
	- mtimecmpStart - clint->nThread * 8;
	reserved.emplace_back("reserved1", reserved1_size);

	// Sanity check
	assert((int) clint->pioSize <= maxBankSize);

	// Initialize registers
	for (int i = 0; i < clint->nThread; i++) {
	msip.emplace_back(std::string("msip") + std::to_string(i), 0);
	mtimecmp.emplace_back(std::string("mtimecmp") + std::to_string(i), 0);
	}

	// Add registers to bank
	for (int i = 0; i < clint->nThread; i++) {
	auto read_cb = std::bind(&Clint::readMSIP, clint, _1, i);
	msip[i].reader(read_cb);
	auto write_cb = std::bind(&Clint::writeMSIP, clint, _1, _2, i);
	msip[i].writer(write_cb);
	addRegister(msip[i]);
	}
	addRegister(reserved[0]);
	for (int i = 0; i < clint->nThread; i++) {
	addRegister(mtimecmp[i]);
	}
	addRegister(reserved[1]);
	mtime.readonly();
	addRegister(mtime);
	}

	uint32_t
	Clint::readMSIP(Register32& reg, const int thread_id)
	{
	// To avoid discrepancies if mip is externally set using remote_gdb etc.
	auto tc = system->threads[thread_id];
	RegVal mip = tc->readMiscReg(MISCREG_IP);
	uint32_t msip = bits<uint32_t>(mip, ExceptionCode::INT_SOFTWARE_MACHINE);
	reg.update(msip);
	return reg.get();
	};

	void
	Clint::writeMSIP(Register32& reg, const uint32_t& data, const int thread_id)
	{
	reg.update(data);
	assert(data <= 1);
	auto tc = system->threads[thread_id];
	if (data > 0) {
	DPRINTF(Clint, "MSIP posted - thread: %d\n", thread_id);
	tc->getCpuPtr()->postInterrupt(tc->threadId(),
	ExceptionCode::INT_SOFTWARE_MACHINE, 0);
	} else {
	DPRINTF(Clint, "MSIP cleared - thread: %d\n", thread_id);
	tc->getCpuPtr()->clearInterrupt(tc->threadId(),
	ExceptionCode::INT_SOFTWARE_MACHINE, 0);
	}
	};

	Tick
	Clint::read(PacketPtr pkt)
	{
	// Check for atomic operation
	bool is_atomic = pkt->isAtomicOp() && pkt->cmd == MemCmd::SwapReq;
	DPRINTF(Clint,
	"Read request - addr: %#x, size: %#x, atomic:%d\n",
	pkt->getAddr(), pkt->getSize(), is_atomic);

	// Perform register read
	registers.read(pkt->getAddr(), pkt->getPtr<void>(), pkt->getSize());

	if (is_atomic) {
	// Perform atomic operation
	(*(pkt->getAtomicOp()))(pkt->getPtr<uint8_t>());
	return write(pkt);
	} else {
	pkt->makeResponse();
	return pioDelay;
	}
	}

	Tick
	Clint::write(PacketPtr pkt)
	{
	DPRINTF(Clint,
	"Write request - addr: %#x, size: %#x\n",
	pkt->getAddr(), pkt->getSize());

	// Perform register write
	registers.write(pkt->getAddr(), pkt->getPtr<void>(), pkt->getSize());

	pkt->makeResponse();
	return pioDelay;
	}

	void
	Clint::init()
	{
	registers.init();
	BasicPioDevice::init();
	}

	Port &
	Clint::getPort(const std::string &if_name, PortID idx)
	{
	if (if_name == "int_pin")
	return signal;
	else
	return BasicPioDevice::getPort(if_name, idx);
	}

	void
	Clint::serialize(CheckpointOut &cp) const
	{
	for (auto const &reg: registers.msip) {
	paramOut(cp, reg.name(), reg);
	}
	for (auto const &reg: registers.mtimecmp) {
	paramOut(cp, reg.name(), reg);
	}
	paramOut(cp, "mtime", registers.mtime);
	}

	void
	Clint::unserialize(CheckpointIn &cp)
	{
	for (auto &reg: registers.msip) {
	paramIn(cp, reg.name(), reg);
	}
	for (auto &reg: registers.mtimecmp) {
	paramIn(cp, reg.name(), reg);
	}
	paramIn(cp, "mtime", registers.mtime);
	}

	} // namespace gem5