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 "qemu/osdep.h" 25 #include "hw/hw.h" 26 #include "hw/isa/isa.h" 27 #include "qemu/main-loop.h" 28 #include "trace.h" 29 30 /* #define DEBUG_DMA */ 31 32 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__) 33 #ifdef DEBUG_DMA 34 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__) 35 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__) 36 #else 37 #define linfo(...) 38 #define ldebug(...) 39 #endif 40 41 struct dma_regs { 42 int now[2]; 43 uint16_t base[2]; 44 uint8_t mode; 45 uint8_t page; 46 uint8_t pageh; 47 uint8_t dack; 48 uint8_t eop; 49 DMA_transfer_handler transfer_handler; 50 void *opaque; 51 }; 52 53 #define ADDR 0 54 #define COUNT 1 55 56 static struct dma_cont { 57 uint8_t status; 58 uint8_t command; 59 uint8_t mask; 60 uint8_t flip_flop; 61 int dshift; 62 struct dma_regs regs[4]; 63 MemoryRegion channel_io; 64 MemoryRegion cont_io; 65 } dma_controllers[2]; 66 67 enum { 68 CMD_MEMORY_TO_MEMORY = 0x01, 69 CMD_FIXED_ADDRESS = 0x02, 70 CMD_BLOCK_CONTROLLER = 0x04, 71 CMD_COMPRESSED_TIME = 0x08, 72 CMD_CYCLIC_PRIORITY = 0x10, 73 CMD_EXTENDED_WRITE = 0x20, 74 CMD_LOW_DREQ = 0x40, 75 CMD_LOW_DACK = 0x80, 76 CMD_NOT_SUPPORTED = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS 77 | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE 78 | CMD_LOW_DREQ | CMD_LOW_DACK 79 80 }; 81 82 static void DMA_run (void); 83 84 static int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0}; 85 86 static void write_page (void *opaque, uint32_t nport, uint32_t data) 87 { 88 struct dma_cont *d = opaque; 89 int ichan; 90 91 ichan = channels[nport & 7]; 92 if (-1 == ichan) { 93 dolog ("invalid channel %#x %#x\n", nport, data); 94 return; 95 } 96 d->regs[ichan].page = data; 97 } 98 99 static void write_pageh (void *opaque, uint32_t nport, uint32_t data) 100 { 101 struct dma_cont *d = opaque; 102 int ichan; 103 104 ichan = channels[nport & 7]; 105 if (-1 == ichan) { 106 dolog ("invalid channel %#x %#x\n", nport, data); 107 return; 108 } 109 d->regs[ichan].pageh = data; 110 } 111 112 static uint32_t read_page (void *opaque, uint32_t nport) 113 { 114 struct dma_cont *d = opaque; 115 int ichan; 116 117 ichan = channels[nport & 7]; 118 if (-1 == ichan) { 119 dolog ("invalid channel read %#x\n", nport); 120 return 0; 121 } 122 return d->regs[ichan].page; 123 } 124 125 static uint32_t read_pageh (void *opaque, uint32_t nport) 126 { 127 struct dma_cont *d = opaque; 128 int ichan; 129 130 ichan = channels[nport & 7]; 131 if (-1 == ichan) { 132 dolog ("invalid channel read %#x\n", nport); 133 return 0; 134 } 135 return d->regs[ichan].pageh; 136 } 137 138 static inline void init_chan (struct dma_cont *d, int ichan) 139 { 140 struct dma_regs *r; 141 142 r = d->regs + ichan; 143 r->now[ADDR] = r->base[ADDR] << d->dshift; 144 r->now[COUNT] = 0; 145 } 146 147 static inline int getff (struct dma_cont *d) 148 { 149 int ff; 150 151 ff = d->flip_flop; 152 d->flip_flop = !ff; 153 return ff; 154 } 155 156 static uint64_t read_chan(void *opaque, hwaddr nport, unsigned size) 157 { 158 struct dma_cont *d = opaque; 159 int ichan, nreg, iport, ff, val, dir; 160 struct dma_regs *r; 161 162 iport = (nport >> d->dshift) & 0x0f; 163 ichan = iport >> 1; 164 nreg = iport & 1; 165 r = d->regs + ichan; 166 167 dir = ((r->mode >> 5) & 1) ? -1 : 1; 168 ff = getff (d); 169 if (nreg) 170 val = (r->base[COUNT] << d->dshift) - r->now[COUNT]; 171 else 172 val = r->now[ADDR] + r->now[COUNT] * dir; 173 174 ldebug ("read_chan %#x -> %d\n", iport, val); 175 return (val >> (d->dshift + (ff << 3))) & 0xff; 176 } 177 178 static void write_chan(void *opaque, hwaddr nport, uint64_t data, 179 unsigned size) 180 { 181 struct dma_cont *d = opaque; 182 int iport, ichan, nreg; 183 struct dma_regs *r; 184 185 iport = (nport >> d->dshift) & 0x0f; 186 ichan = iport >> 1; 187 nreg = iport & 1; 188 r = d->regs + ichan; 189 if (getff (d)) { 190 r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00); 191 init_chan (d, ichan); 192 } else { 193 r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff); 194 } 195 } 196 197 static void write_cont(void *opaque, hwaddr nport, uint64_t data, 198 unsigned size) 199 { 200 struct dma_cont *d = opaque; 201 int iport, ichan = 0; 202 203 iport = (nport >> d->dshift) & 0x0f; 204 switch (iport) { 205 case 0x00: /* command */ 206 if ((data != 0) && (data & CMD_NOT_SUPPORTED)) { 207 dolog("command %"PRIx64" not supported\n", data); 208 return; 209 } 210 d->command = data; 211 break; 212 213 case 0x01: 214 ichan = data & 3; 215 if (data & 4) { 216 d->status |= 1 << (ichan + 4); 217 } 218 else { 219 d->status &= ~(1 << (ichan + 4)); 220 } 221 d->status &= ~(1 << ichan); 222 DMA_run(); 223 break; 224 225 case 0x02: /* single mask */ 226 if (data & 4) 227 d->mask |= 1 << (data & 3); 228 else 229 d->mask &= ~(1 << (data & 3)); 230 DMA_run(); 231 break; 232 233 case 0x03: /* mode */ 234 { 235 ichan = data & 3; 236 #ifdef DEBUG_DMA 237 { 238 int op, ai, dir, opmode; 239 op = (data >> 2) & 3; 240 ai = (data >> 4) & 1; 241 dir = (data >> 5) & 1; 242 opmode = (data >> 6) & 3; 243 244 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n", 245 ichan, op, ai, dir, opmode); 246 } 247 #endif 248 d->regs[ichan].mode = data; 249 break; 250 } 251 252 case 0x04: /* clear flip flop */ 253 d->flip_flop = 0; 254 break; 255 256 case 0x05: /* reset */ 257 d->flip_flop = 0; 258 d->mask = ~0; 259 d->status = 0; 260 d->command = 0; 261 break; 262 263 case 0x06: /* clear mask for all channels */ 264 d->mask = 0; 265 DMA_run(); 266 break; 267 268 case 0x07: /* write mask for all channels */ 269 d->mask = data; 270 DMA_run(); 271 break; 272 273 default: 274 dolog ("unknown iport %#x\n", iport); 275 break; 276 } 277 278 #ifdef DEBUG_DMA 279 if (0xc != iport) { 280 linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n", 281 nport, ichan, data); 282 } 283 #endif 284 } 285 286 static uint64_t read_cont(void *opaque, hwaddr nport, unsigned size) 287 { 288 struct dma_cont *d = opaque; 289 int iport, val; 290 291 iport = (nport >> d->dshift) & 0x0f; 292 switch (iport) { 293 case 0x00: /* status */ 294 val = d->status; 295 d->status &= 0xf0; 296 break; 297 case 0x01: /* mask */ 298 val = d->mask; 299 break; 300 default: 301 val = 0; 302 break; 303 } 304 305 ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val); 306 return val; 307 } 308 309 int DMA_get_channel_mode (int nchan) 310 { 311 return dma_controllers[nchan > 3].regs[nchan & 3].mode; 312 } 313 314 void DMA_hold_DREQ (int nchan) 315 { 316 int ncont, ichan; 317 318 ncont = nchan > 3; 319 ichan = nchan & 3; 320 linfo ("held cont=%d chan=%d\n", ncont, ichan); 321 dma_controllers[ncont].status |= 1 << (ichan + 4); 322 DMA_run(); 323 } 324 325 void DMA_release_DREQ (int nchan) 326 { 327 int ncont, ichan; 328 329 ncont = nchan > 3; 330 ichan = nchan & 3; 331 linfo ("released cont=%d chan=%d\n", ncont, ichan); 332 dma_controllers[ncont].status &= ~(1 << (ichan + 4)); 333 DMA_run(); 334 } 335 336 static void channel_run (int ncont, int ichan) 337 { 338 int n; 339 struct dma_regs *r = &dma_controllers[ncont].regs[ichan]; 340 #ifdef DEBUG_DMA 341 int dir, opmode; 342 343 dir = (r->mode >> 5) & 1; 344 opmode = (r->mode >> 6) & 3; 345 346 if (dir) { 347 dolog ("DMA in address decrement mode\n"); 348 } 349 if (opmode != 1) { 350 dolog ("DMA not in single mode select %#x\n", opmode); 351 } 352 #endif 353 354 n = r->transfer_handler (r->opaque, ichan + (ncont << 2), 355 r->now[COUNT], (r->base[COUNT] + 1) << ncont); 356 r->now[COUNT] = n; 357 ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont); 358 } 359 360 static QEMUBH *dma_bh; 361 static bool dma_bh_scheduled; 362 363 static void DMA_run (void) 364 { 365 struct dma_cont *d; 366 int icont, ichan; 367 int rearm = 0; 368 static int running = 0; 369 370 if (running) { 371 rearm = 1; 372 goto out; 373 } else { 374 running = 1; 375 } 376 377 d = dma_controllers; 378 379 for (icont = 0; icont < 2; icont++, d++) { 380 for (ichan = 0; ichan < 4; ichan++) { 381 int mask; 382 383 mask = 1 << ichan; 384 385 if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) { 386 channel_run (icont, ichan); 387 rearm = 1; 388 } 389 } 390 } 391 392 running = 0; 393 out: 394 if (rearm) { 395 qemu_bh_schedule_idle(dma_bh); 396 dma_bh_scheduled = true; 397 } 398 } 399 400 static void DMA_run_bh(void *unused) 401 { 402 dma_bh_scheduled = false; 403 DMA_run(); 404 } 405 406 void DMA_register_channel (int nchan, 407 DMA_transfer_handler transfer_handler, 408 void *opaque) 409 { 410 struct dma_regs *r; 411 int ichan, ncont; 412 413 ncont = nchan > 3; 414 ichan = nchan & 3; 415 416 r = dma_controllers[ncont].regs + ichan; 417 r->transfer_handler = transfer_handler; 418 r->opaque = opaque; 419 } 420 421 int DMA_read_memory (int nchan, void *buf, int pos, int len) 422 { 423 struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3]; 424 hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR]; 425 426 if (r->mode & 0x20) { 427 int i; 428 uint8_t *p = buf; 429 430 cpu_physical_memory_read (addr - pos - len, buf, len); 431 /* What about 16bit transfers? */ 432 for (i = 0; i < len >> 1; i++) { 433 uint8_t b = p[len - i - 1]; 434 p[i] = b; 435 } 436 } 437 else 438 cpu_physical_memory_read (addr + pos, buf, len); 439 440 return len; 441 } 442 443 int DMA_write_memory (int nchan, void *buf, int pos, int len) 444 { 445 struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3]; 446 hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR]; 447 448 if (r->mode & 0x20) { 449 int i; 450 uint8_t *p = buf; 451 452 cpu_physical_memory_write (addr - pos - len, buf, len); 453 /* What about 16bit transfers? */ 454 for (i = 0; i < len; i++) { 455 uint8_t b = p[len - i - 1]; 456 p[i] = b; 457 } 458 } 459 else 460 cpu_physical_memory_write (addr + pos, buf, len); 461 462 return len; 463 } 464 465 /* request the emulator to transfer a new DMA memory block ASAP (even 466 * if the idle bottom half would not have exited the iothread yet). 467 */ 468 void DMA_schedule(void) 469 { 470 if (dma_bh_scheduled) { 471 qemu_notify_event(); 472 } 473 } 474 475 static void dma_reset(void *opaque) 476 { 477 struct dma_cont *d = opaque; 478 write_cont(d, (0x05 << d->dshift), 0, 1); 479 } 480 481 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len) 482 { 483 trace_i8257_unregistered_dma(nchan, dma_pos, dma_len); 484 return dma_pos; 485 } 486 487 488 static const MemoryRegionOps channel_io_ops = { 489 .read = read_chan, 490 .write = write_chan, 491 .endianness = DEVICE_NATIVE_ENDIAN, 492 .impl = { 493 .min_access_size = 1, 494 .max_access_size = 1, 495 }, 496 }; 497 498 /* IOport from page_base */ 499 static const MemoryRegionPortio page_portio_list[] = { 500 { 0x01, 3, 1, .write = write_page, .read = read_page, }, 501 { 0x07, 1, 1, .write = write_page, .read = read_page, }, 502 PORTIO_END_OF_LIST(), 503 }; 504 505 /* IOport from pageh_base */ 506 static const MemoryRegionPortio pageh_portio_list[] = { 507 { 0x01, 3, 1, .write = write_pageh, .read = read_pageh, }, 508 { 0x07, 3, 1, .write = write_pageh, .read = read_pageh, }, 509 PORTIO_END_OF_LIST(), 510 }; 511 512 static const MemoryRegionOps cont_io_ops = { 513 .read = read_cont, 514 .write = write_cont, 515 .endianness = DEVICE_NATIVE_ENDIAN, 516 .impl = { 517 .min_access_size = 1, 518 .max_access_size = 1, 519 }, 520 }; 521 522 /* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */ 523 static void dma_init2(struct dma_cont *d, int base, int dshift, 524 int page_base, int pageh_base) 525 { 526 int i; 527 528 d->dshift = dshift; 529 530 memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d, 531 "dma-chan", 8 << d->dshift); 532 memory_region_add_subregion(isa_address_space_io(NULL), 533 base, &d->channel_io); 534 535 isa_register_portio_list(NULL, page_base, page_portio_list, d, 536 "dma-page"); 537 if (pageh_base >= 0) { 538 isa_register_portio_list(NULL, pageh_base, pageh_portio_list, d, 539 "dma-pageh"); 540 } 541 542 memory_region_init_io(&d->cont_io, NULL, &cont_io_ops, d, "dma-cont", 543 8 << d->dshift); 544 memory_region_add_subregion(isa_address_space_io(NULL), 545 base + (8 << d->dshift), &d->cont_io); 546 547 qemu_register_reset(dma_reset, d); 548 dma_reset(d); 549 for (i = 0; i < ARRAY_SIZE (d->regs); ++i) { 550 d->regs[i].transfer_handler = dma_phony_handler; 551 } 552 } 553 554 static const VMStateDescription vmstate_dma_regs = { 555 .name = "dma_regs", 556 .version_id = 1, 557 .minimum_version_id = 1, 558 .fields = (VMStateField[]) { 559 VMSTATE_INT32_ARRAY(now, struct dma_regs, 2), 560 VMSTATE_UINT16_ARRAY(base, struct dma_regs, 2), 561 VMSTATE_UINT8(mode, struct dma_regs), 562 VMSTATE_UINT8(page, struct dma_regs), 563 VMSTATE_UINT8(pageh, struct dma_regs), 564 VMSTATE_UINT8(dack, struct dma_regs), 565 VMSTATE_UINT8(eop, struct dma_regs), 566 VMSTATE_END_OF_LIST() 567 } 568 }; 569 570 static int dma_post_load(void *opaque, int version_id) 571 { 572 DMA_run(); 573 574 return 0; 575 } 576 577 static const VMStateDescription vmstate_dma = { 578 .name = "dma", 579 .version_id = 1, 580 .minimum_version_id = 1, 581 .post_load = dma_post_load, 582 .fields = (VMStateField[]) { 583 VMSTATE_UINT8(command, struct dma_cont), 584 VMSTATE_UINT8(mask, struct dma_cont), 585 VMSTATE_UINT8(flip_flop, struct dma_cont), 586 VMSTATE_INT32(dshift, struct dma_cont), 587 VMSTATE_STRUCT_ARRAY(regs, struct dma_cont, 4, 1, vmstate_dma_regs, struct dma_regs), 588 VMSTATE_END_OF_LIST() 589 } 590 }; 591 592 void DMA_init(int high_page_enable) 593 { 594 dma_init2(&dma_controllers[0], 0x00, 0, 0x80, high_page_enable ? 0x480 : -1); 595 dma_init2(&dma_controllers[1], 0xc0, 1, 0x88, high_page_enable ? 0x488 : -1); 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