1 /* 2 * QEMU DMA emulation 3 * 4 * Copyright (c) 2003-2004 Vassili Karpov (malc) 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "hw/hw.h" 25 #include "hw/isa/isa.h" 26 #include "qemu/main-loop.h" 27 28 /* #define DEBUG_DMA */ 29 30 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__) 31 #ifdef DEBUG_DMA 32 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__) 33 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__) 34 #else 35 #define linfo(...) 36 #define ldebug(...) 37 #endif 38 39 struct dma_regs { 40 int now[2]; 41 uint16_t base[2]; 42 uint8_t mode; 43 uint8_t page; 44 uint8_t pageh; 45 uint8_t dack; 46 uint8_t eop; 47 DMA_transfer_handler transfer_handler; 48 void *opaque; 49 }; 50 51 #define ADDR 0 52 #define COUNT 1 53 54 static struct dma_cont { 55 uint8_t status; 56 uint8_t command; 57 uint8_t mask; 58 uint8_t flip_flop; 59 int dshift; 60 struct dma_regs regs[4]; 61 qemu_irq *cpu_request_exit; 62 MemoryRegion channel_io; 63 MemoryRegion cont_io; 64 } dma_controllers[2]; 65 66 enum { 67 CMD_MEMORY_TO_MEMORY = 0x01, 68 CMD_FIXED_ADDRESS = 0x02, 69 CMD_BLOCK_CONTROLLER = 0x04, 70 CMD_COMPRESSED_TIME = 0x08, 71 CMD_CYCLIC_PRIORITY = 0x10, 72 CMD_EXTENDED_WRITE = 0x20, 73 CMD_LOW_DREQ = 0x40, 74 CMD_LOW_DACK = 0x80, 75 CMD_NOT_SUPPORTED = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS 76 | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE 77 | CMD_LOW_DREQ | CMD_LOW_DACK 78 79 }; 80 81 static void DMA_run (void); 82 83 static int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0}; 84 85 static void write_page (void *opaque, uint32_t nport, uint32_t data) 86 { 87 struct dma_cont *d = opaque; 88 int ichan; 89 90 ichan = channels[nport & 7]; 91 if (-1 == ichan) { 92 dolog ("invalid channel %#x %#x\n", nport, data); 93 return; 94 } 95 d->regs[ichan].page = data; 96 } 97 98 static void write_pageh (void *opaque, uint32_t nport, uint32_t data) 99 { 100 struct dma_cont *d = opaque; 101 int ichan; 102 103 ichan = channels[nport & 7]; 104 if (-1 == ichan) { 105 dolog ("invalid channel %#x %#x\n", nport, data); 106 return; 107 } 108 d->regs[ichan].pageh = data; 109 } 110 111 static uint32_t read_page (void *opaque, uint32_t nport) 112 { 113 struct dma_cont *d = opaque; 114 int ichan; 115 116 ichan = channels[nport & 7]; 117 if (-1 == ichan) { 118 dolog ("invalid channel read %#x\n", nport); 119 return 0; 120 } 121 return d->regs[ichan].page; 122 } 123 124 static uint32_t read_pageh (void *opaque, uint32_t nport) 125 { 126 struct dma_cont *d = opaque; 127 int ichan; 128 129 ichan = channels[nport & 7]; 130 if (-1 == ichan) { 131 dolog ("invalid channel read %#x\n", nport); 132 return 0; 133 } 134 return d->regs[ichan].pageh; 135 } 136 137 static inline void init_chan (struct dma_cont *d, int ichan) 138 { 139 struct dma_regs *r; 140 141 r = d->regs + ichan; 142 r->now[ADDR] = r->base[ADDR] << d->dshift; 143 r->now[COUNT] = 0; 144 } 145 146 static inline int getff (struct dma_cont *d) 147 { 148 int ff; 149 150 ff = d->flip_flop; 151 d->flip_flop = !ff; 152 return ff; 153 } 154 155 static uint64_t read_chan(void *opaque, hwaddr nport, unsigned size) 156 { 157 struct dma_cont *d = opaque; 158 int ichan, nreg, iport, ff, val, dir; 159 struct dma_regs *r; 160 161 iport = (nport >> d->dshift) & 0x0f; 162 ichan = iport >> 1; 163 nreg = iport & 1; 164 r = d->regs + ichan; 165 166 dir = ((r->mode >> 5) & 1) ? -1 : 1; 167 ff = getff (d); 168 if (nreg) 169 val = (r->base[COUNT] << d->dshift) - r->now[COUNT]; 170 else 171 val = r->now[ADDR] + r->now[COUNT] * dir; 172 173 ldebug ("read_chan %#x -> %d\n", iport, val); 174 return (val >> (d->dshift + (ff << 3))) & 0xff; 175 } 176 177 static void write_chan(void *opaque, hwaddr nport, uint64_t data, 178 unsigned size) 179 { 180 struct dma_cont *d = opaque; 181 int iport, ichan, nreg; 182 struct dma_regs *r; 183 184 iport = (nport >> d->dshift) & 0x0f; 185 ichan = iport >> 1; 186 nreg = iport & 1; 187 r = d->regs + ichan; 188 if (getff (d)) { 189 r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00); 190 init_chan (d, ichan); 191 } else { 192 r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff); 193 } 194 } 195 196 static void write_cont(void *opaque, hwaddr nport, uint64_t data, 197 unsigned size) 198 { 199 struct dma_cont *d = opaque; 200 int iport, ichan = 0; 201 202 iport = (nport >> d->dshift) & 0x0f; 203 switch (iport) { 204 case 0x00: /* command */ 205 if ((data != 0) && (data & CMD_NOT_SUPPORTED)) { 206 dolog("command %"PRIx64" not supported\n", data); 207 return; 208 } 209 d->command = data; 210 break; 211 212 case 0x01: 213 ichan = data & 3; 214 if (data & 4) { 215 d->status |= 1 << (ichan + 4); 216 } 217 else { 218 d->status &= ~(1 << (ichan + 4)); 219 } 220 d->status &= ~(1 << ichan); 221 DMA_run(); 222 break; 223 224 case 0x02: /* single mask */ 225 if (data & 4) 226 d->mask |= 1 << (data & 3); 227 else 228 d->mask &= ~(1 << (data & 3)); 229 DMA_run(); 230 break; 231 232 case 0x03: /* mode */ 233 { 234 ichan = data & 3; 235 #ifdef DEBUG_DMA 236 { 237 int op, ai, dir, opmode; 238 op = (data >> 2) & 3; 239 ai = (data >> 4) & 1; 240 dir = (data >> 5) & 1; 241 opmode = (data >> 6) & 3; 242 243 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n", 244 ichan, op, ai, dir, opmode); 245 } 246 #endif 247 d->regs[ichan].mode = data; 248 break; 249 } 250 251 case 0x04: /* clear flip flop */ 252 d->flip_flop = 0; 253 break; 254 255 case 0x05: /* reset */ 256 d->flip_flop = 0; 257 d->mask = ~0; 258 d->status = 0; 259 d->command = 0; 260 break; 261 262 case 0x06: /* clear mask for all channels */ 263 d->mask = 0; 264 DMA_run(); 265 break; 266 267 case 0x07: /* write mask for all channels */ 268 d->mask = data; 269 DMA_run(); 270 break; 271 272 default: 273 dolog ("unknown iport %#x\n", iport); 274 break; 275 } 276 277 #ifdef DEBUG_DMA 278 if (0xc != iport) { 279 linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n", 280 nport, ichan, data); 281 } 282 #endif 283 } 284 285 static uint64_t read_cont(void *opaque, hwaddr nport, unsigned size) 286 { 287 struct dma_cont *d = opaque; 288 int iport, val; 289 290 iport = (nport >> d->dshift) & 0x0f; 291 switch (iport) { 292 case 0x00: /* status */ 293 val = d->status; 294 d->status &= 0xf0; 295 break; 296 case 0x01: /* mask */ 297 val = d->mask; 298 break; 299 default: 300 val = 0; 301 break; 302 } 303 304 ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val); 305 return val; 306 } 307 308 int DMA_get_channel_mode (int nchan) 309 { 310 return dma_controllers[nchan > 3].regs[nchan & 3].mode; 311 } 312 313 void DMA_hold_DREQ (int nchan) 314 { 315 int ncont, ichan; 316 317 ncont = nchan > 3; 318 ichan = nchan & 3; 319 linfo ("held cont=%d chan=%d\n", ncont, ichan); 320 dma_controllers[ncont].status |= 1 << (ichan + 4); 321 DMA_run(); 322 } 323 324 void DMA_release_DREQ (int nchan) 325 { 326 int ncont, ichan; 327 328 ncont = nchan > 3; 329 ichan = nchan & 3; 330 linfo ("released cont=%d chan=%d\n", ncont, ichan); 331 dma_controllers[ncont].status &= ~(1 << (ichan + 4)); 332 DMA_run(); 333 } 334 335 static void channel_run (int ncont, int ichan) 336 { 337 int n; 338 struct dma_regs *r = &dma_controllers[ncont].regs[ichan]; 339 #ifdef DEBUG_DMA 340 int dir, opmode; 341 342 dir = (r->mode >> 5) & 1; 343 opmode = (r->mode >> 6) & 3; 344 345 if (dir) { 346 dolog ("DMA in address decrement mode\n"); 347 } 348 if (opmode != 1) { 349 dolog ("DMA not in single mode select %#x\n", opmode); 350 } 351 #endif 352 353 n = r->transfer_handler (r->opaque, ichan + (ncont << 2), 354 r->now[COUNT], (r->base[COUNT] + 1) << ncont); 355 r->now[COUNT] = n; 356 ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont); 357 } 358 359 static QEMUBH *dma_bh; 360 361 static void DMA_run (void) 362 { 363 struct dma_cont *d; 364 int icont, ichan; 365 int rearm = 0; 366 static int running = 0; 367 368 if (running) { 369 rearm = 1; 370 goto out; 371 } else { 372 running = 1; 373 } 374 375 d = dma_controllers; 376 377 for (icont = 0; icont < 2; icont++, d++) { 378 for (ichan = 0; ichan < 4; ichan++) { 379 int mask; 380 381 mask = 1 << ichan; 382 383 if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) { 384 channel_run (icont, ichan); 385 rearm = 1; 386 } 387 } 388 } 389 390 running = 0; 391 out: 392 if (rearm) 393 qemu_bh_schedule_idle(dma_bh); 394 } 395 396 static void DMA_run_bh(void *unused) 397 { 398 DMA_run(); 399 } 400 401 void DMA_register_channel (int nchan, 402 DMA_transfer_handler transfer_handler, 403 void *opaque) 404 { 405 struct dma_regs *r; 406 int ichan, ncont; 407 408 ncont = nchan > 3; 409 ichan = nchan & 3; 410 411 r = dma_controllers[ncont].regs + ichan; 412 r->transfer_handler = transfer_handler; 413 r->opaque = opaque; 414 } 415 416 int DMA_read_memory (int nchan, void *buf, int pos, int len) 417 { 418 struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3]; 419 hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR]; 420 421 if (r->mode & 0x20) { 422 int i; 423 uint8_t *p = buf; 424 425 cpu_physical_memory_read (addr - pos - len, buf, len); 426 /* What about 16bit transfers? */ 427 for (i = 0; i < len >> 1; i++) { 428 uint8_t b = p[len - i - 1]; 429 p[i] = b; 430 } 431 } 432 else 433 cpu_physical_memory_read (addr + pos, buf, len); 434 435 return len; 436 } 437 438 int DMA_write_memory (int nchan, void *buf, int pos, int len) 439 { 440 struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3]; 441 hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR]; 442 443 if (r->mode & 0x20) { 444 int i; 445 uint8_t *p = buf; 446 447 cpu_physical_memory_write (addr - pos - len, buf, len); 448 /* What about 16bit transfers? */ 449 for (i = 0; i < len; i++) { 450 uint8_t b = p[len - i - 1]; 451 p[i] = b; 452 } 453 } 454 else 455 cpu_physical_memory_write (addr + pos, buf, len); 456 457 return len; 458 } 459 460 /* request the emulator to transfer a new DMA memory block ASAP */ 461 void DMA_schedule(int nchan) 462 { 463 struct dma_cont *d = &dma_controllers[nchan > 3]; 464 465 qemu_irq_pulse(*d->cpu_request_exit); 466 } 467 468 static void dma_reset(void *opaque) 469 { 470 struct dma_cont *d = opaque; 471 write_cont(d, (0x05 << d->dshift), 0, 1); 472 } 473 474 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len) 475 { 476 dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n", 477 nchan, dma_pos, dma_len); 478 return dma_pos; 479 } 480 481 482 static const MemoryRegionOps channel_io_ops = { 483 .read = read_chan, 484 .write = write_chan, 485 .endianness = DEVICE_NATIVE_ENDIAN, 486 .impl = { 487 .min_access_size = 1, 488 .max_access_size = 1, 489 }, 490 }; 491 492 /* IOport from page_base */ 493 static const MemoryRegionPortio page_portio_list[] = { 494 { 0x01, 3, 1, .write = write_page, .read = read_page, }, 495 { 0x07, 1, 1, .write = write_page, .read = read_page, }, 496 PORTIO_END_OF_LIST(), 497 }; 498 499 /* IOport from pageh_base */ 500 static const MemoryRegionPortio pageh_portio_list[] = { 501 { 0x01, 3, 1, .write = write_pageh, .read = read_pageh, }, 502 { 0x07, 3, 1, .write = write_pageh, .read = read_pageh, }, 503 PORTIO_END_OF_LIST(), 504 }; 505 506 static const MemoryRegionOps cont_io_ops = { 507 .read = read_cont, 508 .write = write_cont, 509 .endianness = DEVICE_NATIVE_ENDIAN, 510 .impl = { 511 .min_access_size = 1, 512 .max_access_size = 1, 513 }, 514 }; 515 516 /* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */ 517 static void dma_init2(struct dma_cont *d, int base, int dshift, 518 int page_base, int pageh_base, 519 qemu_irq *cpu_request_exit) 520 { 521 int i; 522 523 d->dshift = dshift; 524 d->cpu_request_exit = cpu_request_exit; 525 526 memory_region_init_io(&d->channel_io, &channel_io_ops, d, 527 "dma-chan", 8 << d->dshift); 528 memory_region_add_subregion(isa_address_space_io(NULL), 529 base, &d->channel_io); 530 531 isa_register_portio_list(NULL, page_base, page_portio_list, d, 532 "dma-page"); 533 if (pageh_base >= 0) { 534 isa_register_portio_list(NULL, pageh_base, pageh_portio_list, d, 535 "dma-pageh"); 536 } 537 538 memory_region_init_io(&d->cont_io, &cont_io_ops, d, "dma-cont", 539 8 << d->dshift); 540 memory_region_add_subregion(isa_address_space_io(NULL), 541 base + (8 << d->dshift), &d->cont_io); 542 543 qemu_register_reset(dma_reset, d); 544 dma_reset(d); 545 for (i = 0; i < ARRAY_SIZE (d->regs); ++i) { 546 d->regs[i].transfer_handler = dma_phony_handler; 547 } 548 } 549 550 static const VMStateDescription vmstate_dma_regs = { 551 .name = "dma_regs", 552 .version_id = 1, 553 .minimum_version_id = 1, 554 .minimum_version_id_old = 1, 555 .fields = (VMStateField []) { 556 VMSTATE_INT32_ARRAY(now, struct dma_regs, 2), 557 VMSTATE_UINT16_ARRAY(base, struct dma_regs, 2), 558 VMSTATE_UINT8(mode, struct dma_regs), 559 VMSTATE_UINT8(page, struct dma_regs), 560 VMSTATE_UINT8(pageh, struct dma_regs), 561 VMSTATE_UINT8(dack, struct dma_regs), 562 VMSTATE_UINT8(eop, struct dma_regs), 563 VMSTATE_END_OF_LIST() 564 } 565 }; 566 567 static int dma_post_load(void *opaque, int version_id) 568 { 569 DMA_run(); 570 571 return 0; 572 } 573 574 static const VMStateDescription vmstate_dma = { 575 .name = "dma", 576 .version_id = 1, 577 .minimum_version_id = 1, 578 .minimum_version_id_old = 1, 579 .post_load = dma_post_load, 580 .fields = (VMStateField []) { 581 VMSTATE_UINT8(command, struct dma_cont), 582 VMSTATE_UINT8(mask, struct dma_cont), 583 VMSTATE_UINT8(flip_flop, struct dma_cont), 584 VMSTATE_INT32(dshift, struct dma_cont), 585 VMSTATE_STRUCT_ARRAY(regs, struct dma_cont, 4, 1, vmstate_dma_regs, struct dma_regs), 586 VMSTATE_END_OF_LIST() 587 } 588 }; 589 590 void DMA_init(int high_page_enable, qemu_irq *cpu_request_exit) 591 { 592 dma_init2(&dma_controllers[0], 0x00, 0, 0x80, 593 high_page_enable ? 0x480 : -1, cpu_request_exit); 594 dma_init2(&dma_controllers[1], 0xc0, 1, 0x88, 595 high_page_enable ? 0x488 : -1, cpu_request_exit); 596 vmstate_register (NULL, 0, &vmstate_dma, &dma_controllers[0]); 597 vmstate_register (NULL, 1, &vmstate_dma, &dma_controllers[1]); 598 599 dma_bh = qemu_bh_new(DMA_run_bh, NULL); 600 } 601