gem5/src/dev/x86/i8259.cc

210 lines
7.7 KiB
C++

/*
* Copyright (c) 2004-2005 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: Gabe Black
*/
#include "base/bitfield.hh"
#include "dev/x86/i8259.hh"
Tick
X86ISA::I8259::read(PacketPtr pkt)
{
assert(pkt->getSize() == 1);
switch(pkt->getAddr() - pioAddr)
{
case 0x0:
if (readIRR) {
DPRINTF(I8259, "Reading IRR as %#x.\n", IRR);
pkt->set(IRR);
} else {
DPRINTF(I8259, "Reading ISR as %#x.\n", ISR);
pkt->set(ISR);
}
break;
case 0x1:
DPRINTF(I8259, "Reading IMR as %#x.\n", IMR);
pkt->set(IMR);
break;
}
return latency;
}
Tick
X86ISA::I8259::write(PacketPtr pkt)
{
assert(pkt->getSize() == 1);
uint8_t val = pkt->get<uint8_t>();
switch (pkt->getAddr() - pioAddr) {
case 0x0:
if (bits(val, 4)) {
DPRINTF(I8259, "Received initialization command word 1.\n");
IMR = 0;
edgeTriggered = bits(val, 3);
DPRINTF(I8259, "%s triggered mode.\n",
edgeTriggered ? "Edge" : "Level");
cascadeMode = !bits(val, 1);
DPRINTF(I8259, "%s mode.\n",
cascadeMode ? "Cascade" : "Single");
expectICW4 = bits(val, 0);
initControlWord = 1;
DPRINTF(I8259, "Expecting %d more bytes.\n", expectICW4 ? 3 : 2);
} else if (bits(val, 4, 3) == 0) {
DPRINTF(I8259, "Received operation command word 2.\n");
switch (bits(val, 7, 5)) {
case 0x0:
DPRINTF(I8259,
"Subcommand: Rotate in auto-EOI mode (clear).\n");
break;
case 0x1:
DPRINTF(I8259, "Subcommand: Nonspecific EOI.\n");
break;
case 0x2:
DPRINTF(I8259, "Subcommand: No operation.\n");
break;
case 0x3:
DPRINTF(I8259, "Subcommand: Specific EIO.");
DPRINTF(I8259, "Reset In-Service bit %d.\n", bits(val, 2, 0));
break;
case 0x4:
DPRINTF(I8259, "Subcommand: Rotate in auto-EOI mode (set).\n");
break;
case 0x5:
DPRINTF(I8259, "Subcommand: Rotate on nonspecific EOI.\n");
break;
case 0x6:
DPRINTF(I8259, "Subcommand: Set priority command.\n");
DPRINTF(I8259, "Lowest: IRQ%d Highest IRQ%d.\n",
bits(val, 2, 0), (bits(val, 2, 0) + 1) % 8);
break;
case 0x7:
DPRINTF(I8259, "Subcommand: Rotate on specific EOI.\n");
DPRINTF(I8259, "Lowest: IRQ%d Highest IRQ%d.\n",
bits(val, 2, 0), (bits(val, 2, 0) + 1) % 8);
break;
}
} else if (bits(val, 4, 3) == 1) {
DPRINTF(I8259, "Received operation command word 3.\n");
if (bits(val, 7)) {
DPRINTF(I8259, "%s special mask mode.\n",
bits(val, 6) ? "Set" : "Clear");
}
if (bits(val, 1)) {
readIRR = bits(val, 0);
DPRINTF(I8259, "Read %s.\n", readIRR ? "IRR" : "ISR");
}
}
break;
case 0x1:
switch (initControlWord) {
case 0x0:
DPRINTF(I8259, "Received operation command word 1.\n");
DPRINTF(I8259, "Wrote IMR value %#x.\n", val);
IMR = val;
break;
case 0x1:
DPRINTF(I8259, "Received initialization command word 2.\n");
DPRINTF(I8259, "Responsible for vectors %#x-%#x.\n",
val & ~mask(3), val | mask(3));
if (cascadeMode) {
initControlWord++;
} else {
cascadeBits = 0;
initControlWord = 0;
}
break;
case 0x2:
DPRINTF(I8259, "Received initialization command word 3.\n");
if (mode == Enums::I8259Master) {
DPRINTF(I8259, "Slaves attached to IRQs:%s%s%s%s%s%s%s%s\n",
bits(val, 0) ? " 0" : "",
bits(val, 1) ? " 1" : "",
bits(val, 2) ? " 2" : "",
bits(val, 3) ? " 3" : "",
bits(val, 4) ? " 4" : "",
bits(val, 5) ? " 5" : "",
bits(val, 6) ? " 6" : "",
bits(val, 7) ? " 7" : "");
cascadeBits = val;
} else {
DPRINTF(I8259, "Slave ID is %d.\n", val & mask(3));
cascadeBits = val & mask(3);
}
if (expectICW4)
initControlWord++;
else
initControlWord = 0;
break;
case 0x3:
DPRINTF(I8259, "Received initialization command word 4.\n");
if (bits(val, 4)) {
DPRINTF(I8259, "Special fully nested mode.\n");
} else {
DPRINTF(I8259, "Not special fully nested mode.\n");
}
if (bits(val, 3) == 0) {
DPRINTF(I8259, "Nonbuffered.\n");
} else if (bits(val, 2) == 0) {
DPRINTF(I8259, "Buffered.\n");
} else {
DPRINTF(I8259, "Unrecognized buffer mode.\n");
}
DPRINTF(I8259, "%s End Of Interrupt.\n",
bits(val, 1) ? "Automatic" : "Normal");
DPRINTF(I8259, "%s mode.\n", bits(val, 0) ? "80x86" : "MCX-80/85");
initControlWord = 0;
break;
}
break;
}
return latency;
}
void
X86ISA::I8259::signalInterrupt(int line)
{
DPRINTF(I8259, "Interrupt raised on line %d.\n", line);
if (line > 7)
fatal("Line number %d doesn't exist. The max is 7.\n");
if (bits(IMR, line)) {
DPRINTF(I8259, "Interrupt %d was masked.\n", line);
} else {
if (output) {
DPRINTF(I8259, "Propogating interrupt.\n");
output->signalInterrupt();
} else {
warn("Received interrupt but didn't have "
"anyone to tell about it.\n");
}
}
}
X86ISA::I8259 *
I8259Params::create()
{
return new X86ISA::I8259(this);
}