hw/dma/i8257.c

   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 "hw/isa/i8257.h"
  28 #include "qemu/main-loop.h"
  29 #include "trace.h"
  30
  31 #define I8257(obj) \
  32     OBJECT_CHECK(I8257State, (obj), TYPE_I8257)
  33
  34 /* #define DEBUG_DMA */
  35
  36 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
  37 #ifdef DEBUG_DMA
  38 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
  39 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
  40 #else
  41 #define linfo(...)
  42 #define ldebug(...)
  43 #endif
  44
  45 #define ADDR 0
  46 #define COUNT 1
  47
  48 enum {
  49     CMD_MEMORY_TO_MEMORY = 0x01,
  50     CMD_FIXED_ADDRESS    = 0x02,
  51     CMD_BLOCK_CONTROLLER = 0x04,
  52     CMD_COMPRESSED_TIME  = 0x08,
  53     CMD_CYCLIC_PRIORITY  = 0x10,
  54     CMD_EXTENDED_WRITE   = 0x20,
  55     CMD_LOW_DREQ         = 0x40,
  56     CMD_LOW_DACK         = 0x80,
  57     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
  58     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
  59     | CMD_LOW_DREQ | CMD_LOW_DACK
  60
  61 };
  62
  63 static void i8257_dma_run(void *opaque);
  64
  65 static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
  66
  67 static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
  68 {
  69     I8257State *d = opaque;
  70     int ichan;
  71
  72     ichan = channels[nport & 7];
  73     if (-1 == ichan) {
  74         dolog ("invalid channel %#x %#x\n", nport, data);
  75         return;
  76     }
  77     d->regs[ichan].page = data;
  78 }
  79
  80 static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
  81 {
  82     I8257State *d = opaque;
  83     int ichan;
  84
  85     ichan = channels[nport & 7];
  86     if (-1 == ichan) {
  87         dolog ("invalid channel %#x %#x\n", nport, data);
  88         return;
  89     }
  90     d->regs[ichan].pageh = data;
  91 }
  92
  93 static uint32_t i8257_read_page(void *opaque, uint32_t nport)
  94 {
  95     I8257State *d = opaque;
  96     int ichan;
  97
  98     ichan = channels[nport & 7];
  99     if (-1 == ichan) {
 100         dolog ("invalid channel read %#x\n", nport);
 101         return 0;
 102     }
 103     return d->regs[ichan].page;
 104 }
 105
 106 static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
 107 {
 108     I8257State *d = opaque;
 109     int ichan;
 110
 111     ichan = channels[nport & 7];
 112     if (-1 == ichan) {
 113         dolog ("invalid channel read %#x\n", nport);
 114         return 0;
 115     }
 116     return d->regs[ichan].pageh;
 117 }
 118
 119 static inline void i8257_init_chan(I8257State *d, int ichan)
 120 {
 121     I8257Regs *r;
 122
 123     r = d->regs + ichan;
 124     r->now[ADDR] = r->base[ADDR] << d->dshift;
 125     r->now[COUNT] = 0;
 126 }
 127
 128 static inline int i8257_getff(I8257State *d)
 129 {
 130     int ff;
 131
 132     ff = d->flip_flop;
 133     d->flip_flop = !ff;
 134     return ff;
 135 }
 136
 137 static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
 138 {
 139     I8257State *d = opaque;
 140     int ichan, nreg, iport, ff, val, dir;
 141     I8257Regs *r;
 142
 143     iport = (nport >> d->dshift) & 0x0f;
 144     ichan = iport >> 1;
 145     nreg = iport & 1;
 146     r = d->regs + ichan;
 147
 148     dir = ((r->mode >> 5) & 1) ? -1 : 1;
 149     ff = i8257_getff(d);
 150     if (nreg)
 151         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
 152     else
 153         val = r->now[ADDR] + r->now[COUNT] * dir;
 154
 155     ldebug ("read_chan %#x -> %d\n", iport, val);
 156     return (val >> (d->dshift + (ff << 3))) & 0xff;
 157 }
 158
 159 static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
 160                              unsigned int size)
 161 {
 162     I8257State *d = opaque;
 163     int iport, ichan, nreg;
 164     I8257Regs *r;
 165
 166     iport = (nport >> d->dshift) & 0x0f;
 167     ichan = iport >> 1;
 168     nreg = iport & 1;
 169     r = d->regs + ichan;
 170     if (i8257_getff(d)) {
 171         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
 172         i8257_init_chan(d, ichan);
 173     } else {
 174         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
 175     }
 176 }
 177
 178 static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
 179                              unsigned int size)
 180 {
 181     I8257State *d = opaque;
 182     int iport, ichan = 0;
 183
 184     iport = (nport >> d->dshift) & 0x0f;
 185     switch (iport) {
 186     case 0x00:                  /* command */
 187         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
 188             dolog("command %"PRIx64" not supported\n", data);
 189             return;
 190         }
 191         d->command = data;
 192         break;
 193
 194     case 0x01:
 195         ichan = data & 3;
 196         if (data & 4) {
 197             d->status |= 1 << (ichan + 4);
 198         }
 199         else {
 200             d->status &= ~(1 << (ichan + 4));
 201         }
 202         d->status &= ~(1 << ichan);
 203         i8257_dma_run(d);
 204         break;
 205
 206     case 0x02:                  /* single mask */
 207         if (data & 4)
 208             d->mask |= 1 << (data & 3);
 209         else
 210             d->mask &= ~(1 << (data & 3));
 211         i8257_dma_run(d);
 212         break;
 213
 214     case 0x03:                  /* mode */
 215         {
 216             ichan = data & 3;
 217 #ifdef DEBUG_DMA
 218             {
 219                 int op, ai, dir, opmode;
 220                 op = (data >> 2) & 3;
 221                 ai = (data >> 4) & 1;
 222                 dir = (data >> 5) & 1;
 223                 opmode = (data >> 6) & 3;
 224
 225                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
 226                        ichan, op, ai, dir, opmode);
 227             }
 228 #endif
 229             d->regs[ichan].mode = data;
 230             break;
 231         }
 232
 233     case 0x04:                  /* clear flip flop */
 234         d->flip_flop = 0;
 235         break;
 236
 237     case 0x05:                  /* reset */
 238         d->flip_flop = 0;
 239         d->mask = ~0;
 240         d->status = 0;
 241         d->command = 0;
 242         break;
 243
 244     case 0x06:                  /* clear mask for all channels */
 245         d->mask = 0;
 246         i8257_dma_run(d);
 247         break;
 248
 249     case 0x07:                  /* write mask for all channels */
 250         d->mask = data;
 251         i8257_dma_run(d);
 252         break;
 253
 254     default:
 255         dolog ("unknown iport %#x\n", iport);
 256         break;
 257     }
 258
 259 #ifdef DEBUG_DMA
 260     if (0xc != iport) {
 261         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
 262                nport, ichan, data);
 263     }
 264 #endif
 265 }
 266
 267 static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
 268 {
 269     I8257State *d = opaque;
 270     int iport, val;
 271
 272     iport = (nport >> d->dshift) & 0x0f;
 273     switch (iport) {
 274     case 0x00:                  /* status */
 275         val = d->status;
 276         d->status &= 0xf0;
 277         break;
 278     case 0x01:                  /* mask */
 279         val = d->mask;
 280         break;
 281     default:
 282         val = 0;
 283         break;
 284     }
 285
 286     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
 287     return val;
 288 }
 289
 290 static IsaDmaTransferMode i8257_dma_get_transfer_mode(IsaDma *obj, int nchan)
 291 {
 292     I8257State *d = I8257(obj);
 293     return (d->regs[nchan & 3].mode >> 2) & 3;
 294 }
 295
 296 static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
 297 {
 298     I8257State *d = I8257(obj);
 299     return (d->regs[nchan & 3].mode >> 4) & 1;
 300 }
 301
 302 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
 303 {
 304     I8257State *d = I8257(obj);
 305     int ichan;
 306
 307     ichan = nchan & 3;
 308     d->status |= 1 << (ichan + 4);
 309     i8257_dma_run(d);
 310 }
 311
 312 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
 313 {
 314     I8257State *d = I8257(obj);
 315     int ichan;
 316
 317     ichan = nchan & 3;
 318     d->status &= ~(1 << (ichan + 4));
 319     i8257_dma_run(d);
 320 }
 321
 322 static void i8257_channel_run(I8257State *d, int ichan)
 323 {
 324     int ncont = d->dshift;
 325     int n;
 326     I8257Regs *r = &d->regs[ichan];
 327 #ifdef DEBUG_DMA
 328     int dir, opmode;
 329
 330     dir = (r->mode >> 5) & 1;
 331     opmode = (r->mode >> 6) & 3;
 332
 333     if (dir) {
 334         dolog ("DMA in address decrement mode\n");
 335     }
 336     if (opmode != 1) {
 337         dolog ("DMA not in single mode select %#x\n", opmode);
 338     }
 339 #endif
 340
 341     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
 342                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
 343     r->now[COUNT] = n;
 344     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
 345     if (n == (r->base[COUNT] + 1) << ncont) {
 346         ldebug("transfer done\n");
 347         d->status |= (1 << ichan);
 348     }
 349 }
 350
 351 static void i8257_dma_run(void *opaque)
 352 {
 353     I8257State *d = opaque;
 354     int ichan;
 355     int rearm = 0;
 356
 357     if (d->running) {
 358         rearm = 1;
 359         goto out;
 360     } else {
 361         d->running = 1;
 362     }
 363
 364     for (ichan = 0; ichan < 4; ichan++) {
 365         int mask;
 366
 367         mask = 1 << ichan;
 368
 369         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
 370             i8257_channel_run(d, ichan);
 371             rearm = 1;
 372         }
 373     }
 374
 375     d->running = 0;
 376 out:
 377     if (rearm) {
 378         qemu_bh_schedule_idle(d->dma_bh);
 379         d->dma_bh_scheduled = true;
 380     }
 381 }
 382
 383 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
 384                                        IsaDmaTransferHandler transfer_handler,
 385                                        void *opaque)
 386 {
 387     I8257State *d = I8257(obj);
 388     I8257Regs *r;
 389     int ichan;
 390
 391     ichan = nchan & 3;
 392
 393     r = d->regs + ichan;
 394     r->transfer_handler = transfer_handler;
 395     r->opaque = opaque;
 396 }
 397
 398 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
 399                                  int len)
 400 {
 401     I8257State *d = I8257(obj);
 402     I8257Regs *r = &d->regs[nchan & 3];
 403     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 404
 405     if (r->mode & 0x20) {
 406         int i;
 407         uint8_t *p = buf;
 408
 409         cpu_physical_memory_read (addr - pos - len, buf, len);
 410         /* What about 16bit transfers? */
 411         for (i = 0; i < len >> 1; i++) {
 412             uint8_t b = p[len - i - 1];
 413             p[i] = b;
 414         }
 415     }
 416     else
 417         cpu_physical_memory_read (addr + pos, buf, len);
 418
 419     return len;
 420 }
 421
 422 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
 423                                  int len)
 424 {
 425     I8257State *s = I8257(obj);
 426     I8257Regs *r = &s->regs[nchan & 3];
 427     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 428
 429     if (r->mode & 0x20) {
 430         int i;
 431         uint8_t *p = buf;
 432
 433         cpu_physical_memory_write (addr - pos - len, buf, len);
 434         /* What about 16bit transfers? */
 435         for (i = 0; i < len; i++) {
 436             uint8_t b = p[len - i - 1];
 437             p[i] = b;
 438         }
 439     }
 440     else
 441         cpu_physical_memory_write (addr + pos, buf, len);
 442
 443     return len;
 444 }
 445
 446 /* request the emulator to transfer a new DMA memory block ASAP (even
 447  * if the idle bottom half would not have exited the iothread yet).
 448  */
 449 static void i8257_dma_schedule(IsaDma *obj)
 450 {
 451     I8257State *d = I8257(obj);
 452     if (d->dma_bh_scheduled) {
 453         qemu_notify_event();
 454     }
 455 }
 456
 457 static void i8257_reset(DeviceState *dev)
 458 {
 459     I8257State *d = I8257(dev);
 460     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
 461 }
 462
 463 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
 464                                int dma_len)
 465 {
 466     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
 467     return dma_pos;
 468 }
 469
 470
 471 static const MemoryRegionOps channel_io_ops = {
 472     .read = i8257_read_chan,
 473     .write = i8257_write_chan,
 474     .endianness = DEVICE_NATIVE_ENDIAN,
 475     .impl = {
 476         .min_access_size = 1,
 477         .max_access_size = 1,
 478     },
 479 };
 480
 481 /* IOport from page_base */
 482 static const MemoryRegionPortio page_portio_list[] = {
 483     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
 484     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
 485     PORTIO_END_OF_LIST(),
 486 };
 487
 488 /* IOport from pageh_base */
 489 static const MemoryRegionPortio pageh_portio_list[] = {
 490     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
 491     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
 492     PORTIO_END_OF_LIST(),
 493 };
 494
 495 static const MemoryRegionOps cont_io_ops = {
 496     .read = i8257_read_cont,
 497     .write = i8257_write_cont,
 498     .endianness = DEVICE_NATIVE_ENDIAN,
 499     .impl = {
 500         .min_access_size = 1,
 501         .max_access_size = 1,
 502     },
 503 };
 504
 505 static const VMStateDescription vmstate_i8257_regs = {
 506     .name = "dma_regs",
 507     .version_id = 1,
 508     .minimum_version_id = 1,
 509     .fields = (VMStateField[]) {
 510         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
 511         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
 512         VMSTATE_UINT8(mode, I8257Regs),
 513         VMSTATE_UINT8(page, I8257Regs),
 514         VMSTATE_UINT8(pageh, I8257Regs),
 515         VMSTATE_UINT8(dack, I8257Regs),
 516         VMSTATE_UINT8(eop, I8257Regs),
 517         VMSTATE_END_OF_LIST()
 518     }
 519 };
 520
 521 static int i8257_post_load(void *opaque, int version_id)
 522 {
 523     I8257State *d = opaque;
 524     i8257_dma_run(d);
 525
 526     return 0;
 527 }
 528
 529 static const VMStateDescription vmstate_i8257 = {
 530     .name = "dma",
 531     .version_id = 1,
 532     .minimum_version_id = 1,
 533     .post_load = i8257_post_load,
 534     .fields = (VMStateField[]) {
 535         VMSTATE_UINT8(command, I8257State),
 536         VMSTATE_UINT8(mask, I8257State),
 537         VMSTATE_UINT8(flip_flop, I8257State),
 538         VMSTATE_INT32(dshift, I8257State),
 539         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
 540                              I8257Regs),
 541         VMSTATE_END_OF_LIST()
 542     }
 543 };
 544
 545 static void i8257_realize(DeviceState *dev, Error **errp)
 546 {
 547     ISADevice *isa = ISA_DEVICE(dev);
 548     I8257State *d = I8257(dev);
 549     int i;
 550
 551     memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d,
 552                           "dma-chan", 8 << d->dshift);
 553     memory_region_add_subregion(isa_address_space_io(isa),
 554                                 d->base, &d->channel_io);
 555
 556     isa_register_portio_list(isa, &d->portio_page,
 557                              d->page_base, page_portio_list, d,
 558                              "dma-page");
 559     if (d->pageh_base >= 0) {
 560         isa_register_portio_list(isa, &d->portio_pageh,
 561                                  d->pageh_base, pageh_portio_list, d,
 562                                  "dma-pageh");
 563     }
 564
 565     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
 566                           "dma-cont", 8 << d->dshift);
 567     memory_region_add_subregion(isa_address_space_io(isa),
 568                                 d->base + (8 << d->dshift), &d->cont_io);
 569
 570     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
 571         d->regs[i].transfer_handler = i8257_phony_handler;
 572     }
 573
 574     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
 575 }
 576
 577 static Property i8257_properties[] = {
 578     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
 579     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
 580     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
 581     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
 582     DEFINE_PROP_END_OF_LIST()
 583 };
 584
 585 static void i8257_class_init(ObjectClass *klass, void *data)
 586 {
 587     DeviceClass *dc = DEVICE_CLASS(klass);
 588     IsaDmaClass *idc = ISADMA_CLASS(klass);
 589
 590     dc->realize = i8257_realize;
 591     dc->reset = i8257_reset;
 592     dc->vmsd = &vmstate_i8257;
 593     dc->props = i8257_properties;
 594
 595     idc->get_transfer_mode = i8257_dma_get_transfer_mode;
 596     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
 597     idc->read_memory = i8257_dma_read_memory;
 598     idc->write_memory = i8257_dma_write_memory;
 599     idc->hold_DREQ = i8257_dma_hold_DREQ;
 600     idc->release_DREQ = i8257_dma_release_DREQ;
 601     idc->schedule = i8257_dma_schedule;
 602     idc->register_channel = i8257_dma_register_channel;
 603     /* Reason: needs to be wired up by isa_bus_dma() to work */
 604     dc->cannot_instantiate_with_device_add_yet = true;
 605 }
 606
 607 static const TypeInfo i8257_info = {
 608     .name = TYPE_I8257,
 609     .parent = TYPE_ISA_DEVICE,
 610     .instance_size = sizeof(I8257State),
 611     .class_init = i8257_class_init,
 612     .interfaces = (InterfaceInfo[]) {
 613         { TYPE_ISADMA },
 614         { }
 615     }
 616 };
 617
 618 static void i8257_register_types(void)
 619 {
 620     type_register_static(&i8257_info);
 621 }
 622
 623 type_init(i8257_register_types)
 624
 625 void DMA_init(ISABus *bus, int high_page_enable)
 626 {
 627     ISADevice *isa1, *isa2;
 628     DeviceState *d;
 629
 630     isa1 = isa_create(bus, TYPE_I8257);
 631     d = DEVICE(isa1);
 632     qdev_prop_set_int32(d, "base", 0x00);
 633     qdev_prop_set_int32(d, "page-base", 0x80);
 634     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
 635     qdev_prop_set_int32(d, "dshift", 0);
 636     qdev_init_nofail(d);
 637
 638     isa2 = isa_create(bus, TYPE_I8257);
 639     d = DEVICE(isa2);
 640     qdev_prop_set_int32(d, "base", 0xc0);
 641     qdev_prop_set_int32(d, "page-base", 0x88);
 642     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
 643     qdev_prop_set_int32(d, "dshift", 1);
 644     qdev_init_nofail(d);
 645
 646     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
 647 }