i8259.cc revision 5687
1/* 2 * Copyright (c) 2004-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Gabe Black 29 */ 30 31#include "base/bitfield.hh" 32#include "dev/x86/i82094aa.hh" 33#include "dev/x86/i8259.hh" 34 35X86ISA::I8259::I8259(Params * p) : BasicPioDevice(p), IntDev(this), 36 latency(p->pio_latency), output(p->output), 37 mode(p->mode), slave(NULL), 38 IRR(0), ISR(0), IMR(0), 39 readIRR(true), initControlWord(0) 40{ 41 if (output) { 42 I8259 * master; 43 master = dynamic_cast<I8259 *>(output->getDevice()); 44 if (master) 45 master->setSlave(this); 46 I82094AA * ioApic; 47 ioApic = dynamic_cast<I82094AA *>(output->getDevice()); 48 if (ioApic) 49 ioApic->setExtIntPic(this); 50 } 51 pioSize = 2; 52} 53 54Tick 55X86ISA::I8259::read(PacketPtr pkt) 56{ 57 assert(pkt->getSize() == 1); 58 switch(pkt->getAddr() - pioAddr) 59 { 60 case 0x0: 61 if (readIRR) { 62 DPRINTF(I8259, "Reading IRR as %#x.\n", IRR); 63 pkt->set(IRR); 64 } else { 65 DPRINTF(I8259, "Reading ISR as %#x.\n", ISR); 66 pkt->set(ISR); 67 } 68 break; 69 case 0x1: 70 DPRINTF(I8259, "Reading IMR as %#x.\n", IMR); 71 pkt->set(IMR); 72 break; 73 } 74 return latency; 75} 76 77Tick 78X86ISA::I8259::write(PacketPtr pkt) 79{ 80 assert(pkt->getSize() == 1); 81 uint8_t val = pkt->get<uint8_t>(); 82 switch (pkt->getAddr() - pioAddr) { 83 case 0x0: 84 if (bits(val, 4)) { 85 DPRINTF(I8259, "Received initialization command word 1.\n"); 86 IMR = 0; 87 edgeTriggered = bits(val, 3); 88 DPRINTF(I8259, "%s triggered mode.\n", 89 edgeTriggered ? "Edge" : "Level"); 90 cascadeMode = !bits(val, 1); 91 DPRINTF(I8259, "%s mode.\n", 92 cascadeMode ? "Cascade" : "Single"); 93 expectICW4 = bits(val, 0); 94 initControlWord = 1; 95 DPRINTF(I8259, "Expecting %d more bytes.\n", expectICW4 ? 3 : 2); 96 } else if (bits(val, 4, 3) == 0) { 97 DPRINTF(I8259, "Received operation command word 2.\n"); 98 switch (bits(val, 7, 5)) { 99 case 0x0: 100 DPRINTF(I8259, 101 "Subcommand: Rotate in auto-EOI mode (clear).\n"); 102 break; 103 case 0x1: 104 { 105 int line = findMsbSet(ISR); 106 DPRINTF(I8259, "Subcommand: Nonspecific EOI on line %d.\n", 107 line); 108 handleEOI(line); 109 } 110 break; 111 case 0x2: 112 DPRINTF(I8259, "Subcommand: No operation.\n"); 113 break; 114 case 0x3: 115 { 116 int line = bits(val, 2, 0); 117 DPRINTF(I8259, "Subcommand: Specific EIO on line %d.\n", 118 line); 119 handleEOI(line); 120 } 121 break; 122 case 0x4: 123 DPRINTF(I8259, "Subcommand: Rotate in auto-EOI mode (set).\n"); 124 break; 125 case 0x5: 126 DPRINTF(I8259, "Subcommand: Rotate on nonspecific EOI.\n"); 127 break; 128 case 0x6: 129 DPRINTF(I8259, "Subcommand: Set priority command.\n"); 130 DPRINTF(I8259, "Lowest: IRQ%d Highest IRQ%d.\n", 131 bits(val, 2, 0), (bits(val, 2, 0) + 1) % 8); 132 break; 133 case 0x7: 134 DPRINTF(I8259, "Subcommand: Rotate on specific EOI.\n"); 135 DPRINTF(I8259, "Lowest: IRQ%d Highest IRQ%d.\n", 136 bits(val, 2, 0), (bits(val, 2, 0) + 1) % 8); 137 break; 138 } 139 } else if (bits(val, 4, 3) == 1) { 140 DPRINTF(I8259, "Received operation command word 3.\n"); 141 if (bits(val, 7)) { 142 DPRINTF(I8259, "%s special mask mode.\n", 143 bits(val, 6) ? "Set" : "Clear"); 144 } 145 if (bits(val, 1)) { 146 readIRR = bits(val, 0); 147 DPRINTF(I8259, "Read %s.\n", readIRR ? "IRR" : "ISR"); 148 } 149 } 150 break; 151 case 0x1: 152 switch (initControlWord) { 153 case 0x0: 154 DPRINTF(I8259, "Received operation command word 1.\n"); 155 DPRINTF(I8259, "Wrote IMR value %#x.\n", val); 156 IMR = val; 157 break; 158 case 0x1: 159 DPRINTF(I8259, "Received initialization command word 2.\n"); 160 vectorOffset = val & ~mask(3); 161 DPRINTF(I8259, "Responsible for vectors %#x-%#x.\n", 162 vectorOffset, vectorOffset | mask(3)); 163 if (cascadeMode) { 164 initControlWord++; 165 } else { 166 cascadeBits = 0; 167 initControlWord = 0; 168 } 169 break; 170 case 0x2: 171 DPRINTF(I8259, "Received initialization command word 3.\n"); 172 if (mode == Enums::I8259Master) { 173 DPRINTF(I8259, "Slaves attached to IRQs:%s%s%s%s%s%s%s%s\n", 174 bits(val, 0) ? " 0" : "", 175 bits(val, 1) ? " 1" : "", 176 bits(val, 2) ? " 2" : "", 177 bits(val, 3) ? " 3" : "", 178 bits(val, 4) ? " 4" : "", 179 bits(val, 5) ? " 5" : "", 180 bits(val, 6) ? " 6" : "", 181 bits(val, 7) ? " 7" : ""); 182 cascadeBits = val; 183 } else { 184 DPRINTF(I8259, "Slave ID is %d.\n", val & mask(3)); 185 cascadeBits = val & mask(3); 186 } 187 if (expectICW4) 188 initControlWord++; 189 else 190 initControlWord = 0; 191 break; 192 case 0x3: 193 DPRINTF(I8259, "Received initialization command word 4.\n"); 194 if (bits(val, 4)) { 195 DPRINTF(I8259, "Special fully nested mode.\n"); 196 } else { 197 DPRINTF(I8259, "Not special fully nested mode.\n"); 198 } 199 if (bits(val, 3) == 0) { 200 DPRINTF(I8259, "Nonbuffered.\n"); 201 } else if (bits(val, 2) == 0) { 202 DPRINTF(I8259, "Buffered.\n"); 203 } else { 204 DPRINTF(I8259, "Unrecognized buffer mode.\n"); 205 } 206 DPRINTF(I8259, "%s End Of Interrupt.\n", 207 bits(val, 1) ? "Automatic" : "Normal"); 208 DPRINTF(I8259, "%s mode.\n", bits(val, 0) ? "80x86" : "MCX-80/85"); 209 initControlWord = 0; 210 break; 211 } 212 break; 213 } 214 return latency; 215} 216 217void 218X86ISA::I8259::handleEOI(int line) 219{ 220 ISR &= ~(1 << line); 221 // There may be an interrupt that was waiting which can 222 // now be sent. 223 if (IRR) 224 requestInterrupt(findMsbSet(IRR)); 225} 226 227void 228X86ISA::I8259::requestInterrupt(int line) 229{ 230 if (bits(ISR, 7, line) == 0) { 231 if (output) { 232 DPRINTF(I8259, "Propogating interrupt.\n"); 233 output->signalInterrupt(); 234 } else { 235 warn("Received interrupt but didn't have " 236 "anyone to tell about it.\n"); 237 } 238 } 239} 240 241void 242X86ISA::I8259::signalInterrupt(int line) 243{ 244 DPRINTF(I8259, "Interrupt raised on line %d.\n", line); 245 if (line >= NumLines) 246 fatal("Line number %d doesn't exist. The max is %d.\n", 247 line, NumLines - 1); 248 if (bits(IMR, line)) { 249 DPRINTF(I8259, "Interrupt %d was masked.\n", line); 250 } else { 251 IRR |= 1 << line; 252 requestInterrupt(line); 253 } 254} 255 256int 257X86ISA::I8259::getVector() 258{ 259 /* 260 * This code only handles one slave. Since that's how the PC platform 261 * always uses the 8259 PIC, there shouldn't be any need for more. If 262 * there -is- a need for more for some reason, "slave" can become a 263 * vector of slaves. 264 */ 265 int line = findMsbSet(IRR); 266 IRR &= ~(1 << line); 267 DPRINTF(I8259, "Interrupt %d was accepted.\n", line); 268 ISR |= 1 << line; 269 if (slave && bits(cascadeBits, line)) { 270 DPRINTF(I8259, "Interrupt was from slave who will " 271 "provide the vector.\n"); 272 return slave->getVector(); 273 } 274 return line | vectorOffset; 275} 276 277X86ISA::I8259 * 278I8259Params::create() 279{ 280 return new X86ISA::I8259(this); 281} 282