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
  25 #include "qemu/osdep.h"
  26 #include "hw/isa/isa.h"
  27 #include "hw/qdev-properties.h"
  28 #include "migration/vmstate.h"
  29 #include "hw/dma/i8257.h"
  30 #include "qapi/error.h"
  31 #include "qemu/main-loop.h"
  32 #include "qemu/module.h"
  33 #include "qemu/log.h"
  34 #include "trace.h"
  35
  36
  37 /* #define DEBUG_DMA */
  38
  39 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
  40 #ifdef DEBUG_DMA
  41 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
  42 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
  43 #else
  44 #define linfo(...)
  45 #define ldebug(...)
  46 #endif
  47
  48 #define ADDR 0
  49 #define COUNT 1
  50
  51 enum {
  52     CMD_MEMORY_TO_MEMORY = 0x01,
  53     CMD_FIXED_ADDRESS    = 0x02,
  54     CMD_BLOCK_CONTROLLER = 0x04,
  55     CMD_COMPRESSED_TIME  = 0x08,
  56     CMD_CYCLIC_PRIORITY  = 0x10,
  57     CMD_EXTENDED_WRITE   = 0x20,
  58     CMD_LOW_DREQ         = 0x40,
  59     CMD_LOW_DACK         = 0x80,
  60     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
  61     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
  62     | CMD_LOW_DREQ | CMD_LOW_DACK
  63
  64 };
  65
  66 static void i8257_dma_run(void *opaque);
  67
  68 static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
  69
  70 static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
  71 {
  72     I8257State *d = opaque;
  73     int ichan;
  74
  75     ichan = channels[nport & 7];
  76     if (-1 == ichan) {
  77         dolog ("invalid channel %#x %#x\n", nport, data);
  78         return;
  79     }
  80     d->regs[ichan].page = data;
  81 }
  82
  83 static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
  84 {
  85     I8257State *d = opaque;
  86     int ichan;
  87
  88     ichan = channels[nport & 7];
  89     if (-1 == ichan) {
  90         dolog ("invalid channel %#x %#x\n", nport, data);
  91         return;
  92     }
  93     d->regs[ichan].pageh = data;
  94 }
  95
  96 static uint32_t i8257_read_page(void *opaque, uint32_t nport)
  97 {
  98     I8257State *d = opaque;
  99     int ichan;
 100
 101     ichan = channels[nport & 7];
 102     if (-1 == ichan) {
 103         dolog ("invalid channel read %#x\n", nport);
 104         return 0;
 105     }
 106     return d->regs[ichan].page;
 107 }
 108
 109 static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
 110 {
 111     I8257State *d = opaque;
 112     int ichan;
 113
 114     ichan = channels[nport & 7];
 115     if (-1 == ichan) {
 116         dolog ("invalid channel read %#x\n", nport);
 117         return 0;
 118     }
 119     return d->regs[ichan].pageh;
 120 }
 121
 122 static inline void i8257_init_chan(I8257State *d, int ichan)
 123 {
 124     I8257Regs *r;
 125
 126     r = d->regs + ichan;
 127     r->now[ADDR] = r->base[ADDR] << d->dshift;
 128     r->now[COUNT] = 0;
 129 }
 130
 131 static inline int i8257_getff(I8257State *d)
 132 {
 133     int ff;
 134
 135     ff = d->flip_flop;
 136     d->flip_flop = !ff;
 137     return ff;
 138 }
 139
 140 static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
 141 {
 142     I8257State *d = opaque;
 143     int ichan, nreg, iport, ff, val, dir;
 144     I8257Regs *r;
 145
 146     iport = (nport >> d->dshift) & 0x0f;
 147     ichan = iport >> 1;
 148     nreg = iport & 1;
 149     r = d->regs + ichan;
 150
 151     dir = ((r->mode >> 5) & 1) ? -1 : 1;
 152     ff = i8257_getff(d);
 153     if (nreg)
 154         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
 155     else
 156         val = r->now[ADDR] + r->now[COUNT] * dir;
 157
 158     ldebug ("read_chan %#x -> %d\n", iport, val);
 159     return (val >> (d->dshift + (ff << 3))) & 0xff;
 160 }
 161
 162 static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
 163                              unsigned int size)
 164 {
 165     I8257State *d = opaque;
 166     int iport, ichan, nreg;
 167     I8257Regs *r;
 168
 169     iport = (nport >> d->dshift) & 0x0f;
 170     ichan = iport >> 1;
 171     nreg = iport & 1;
 172     r = d->regs + ichan;
 173     if (i8257_getff(d)) {
 174         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
 175         i8257_init_chan(d, ichan);
 176     } else {
 177         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
 178     }
 179 }
 180
 181 static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
 182                              unsigned int size)
 183 {
 184     I8257State *d = opaque;
 185     int iport, ichan = 0;
 186
 187     iport = (nport >> d->dshift) & 0x0f;
 188     switch (iport) {
 189     case 0x00:                  /* command */
 190         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
 191             qemu_log_mask(LOG_UNIMP, "%s: cmd 0x%02"PRIx64" not supported\n",
 192                           __func__, data);
 193             return;
 194         }
 195         d->command = data;
 196         break;
 197
 198     case 0x01:
 199         ichan = data & 3;
 200         if (data & 4) {
 201             d->status |= 1 << (ichan + 4);
 202         }
 203         else {
 204             d->status &= ~(1 << (ichan + 4));
 205         }
 206         d->status &= ~(1 << ichan);
 207         i8257_dma_run(d);
 208         break;
 209
 210     case 0x02:                  /* single mask */
 211         if (data & 4)
 212             d->mask |= 1 << (data & 3);
 213         else
 214             d->mask &= ~(1 << (data & 3));
 215         i8257_dma_run(d);
 216         break;
 217
 218     case 0x03:                  /* mode */
 219         {
 220             ichan = data & 3;
 221 #ifdef DEBUG_DMA
 222             {
 223                 int op, ai, dir, opmode;
 224                 op = (data >> 2) & 3;
 225                 ai = (data >> 4) & 1;
 226                 dir = (data >> 5) & 1;
 227                 opmode = (data >> 6) & 3;
 228
 229                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
 230                        ichan, op, ai, dir, opmode);
 231             }
 232 #endif
 233             d->regs[ichan].mode = data;
 234             break;
 235         }
 236
 237     case 0x04:                  /* clear flip flop */
 238         d->flip_flop = 0;
 239         break;
 240
 241     case 0x05:                  /* reset */
 242         d->flip_flop = 0;
 243         d->mask = ~0;
 244         d->status = 0;
 245         d->command = 0;
 246         break;
 247
 248     case 0x06:                  /* clear mask for all channels */
 249         d->mask = 0;
 250         i8257_dma_run(d);
 251         break;
 252
 253     case 0x07:                  /* write mask for all channels */
 254         d->mask = data;
 255         i8257_dma_run(d);
 256         break;
 257
 258     default:
 259         dolog ("unknown iport %#x\n", iport);
 260         break;
 261     }
 262
 263 #ifdef DEBUG_DMA
 264     if (0xc != iport) {
 265         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
 266                nport, ichan, data);
 267     }
 268 #endif
 269 }
 270
 271 static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
 272 {
 273     I8257State *d = opaque;
 274     int iport, val;
 275
 276     iport = (nport >> d->dshift) & 0x0f;
 277     switch (iport) {
 278     case 0x00:                  /* status */
 279         val = d->status;
 280         d->status &= 0xf0;
 281         break;
 282     case 0x01:                  /* mask */
 283         val = d->mask;
 284         break;
 285     default:
 286         val = 0;
 287         break;
 288     }
 289
 290     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
 291     return val;
 292 }
 293
 294 static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
 295 {
 296     I8257State *d = I8257(obj);
 297     return (d->regs[nchan & 3].mode >> 4) & 1;
 298 }
 299
 300 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
 301 {
 302     I8257State *d = I8257(obj);
 303     int ichan;
 304
 305     ichan = nchan & 3;
 306     d->status |= 1 << (ichan + 4);
 307     i8257_dma_run(d);
 308 }
 309
 310 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
 311 {
 312     I8257State *d = I8257(obj);
 313     int ichan;
 314
 315     ichan = nchan & 3;
 316     d->status &= ~(1 << (ichan + 4));
 317     i8257_dma_run(d);
 318 }
 319
 320 static void i8257_channel_run(I8257State *d, int ichan)
 321 {
 322     int ncont = d->dshift;
 323     int n;
 324     I8257Regs *r = &d->regs[ichan];
 325 #ifdef DEBUG_DMA
 326     int dir, opmode;
 327
 328     dir = (r->mode >> 5) & 1;
 329     opmode = (r->mode >> 6) & 3;
 330
 331     if (dir) {
 332         dolog ("DMA in address decrement mode\n");
 333     }
 334     if (opmode != 1) {
 335         dolog ("DMA not in single mode select %#x\n", opmode);
 336     }
 337 #endif
 338
 339     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
 340                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
 341     r->now[COUNT] = n;
 342     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
 343     if (n == (r->base[COUNT] + 1) << ncont) {
 344         ldebug("transfer done\n");
 345         d->status |= (1 << ichan);
 346     }
 347 }
 348
 349 static void i8257_dma_run(void *opaque)
 350 {
 351     I8257State *d = opaque;
 352     int ichan;
 353     int rearm = 0;
 354
 355     if (d->running) {
 356         rearm = 1;
 357         goto out;
 358     } else {
 359         d->running = 1;
 360     }
 361
 362     for (ichan = 0; ichan < 4; ichan++) {
 363         int mask;
 364
 365         mask = 1 << ichan;
 366
 367         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
 368             i8257_channel_run(d, ichan);
 369             rearm = 1;
 370         }
 371     }
 372
 373     d->running = 0;
 374 out:
 375     if (rearm) {
 376         qemu_bh_schedule_idle(d->dma_bh);
 377         d->dma_bh_scheduled = true;
 378     }
 379 }
 380
 381 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
 382                                        IsaDmaTransferHandler transfer_handler,
 383                                        void *opaque)
 384 {
 385     I8257State *d = I8257(obj);
 386     I8257Regs *r;
 387     int ichan;
 388
 389     ichan = nchan & 3;
 390
 391     r = d->regs + ichan;
 392     r->transfer_handler = transfer_handler;
 393     r->opaque = opaque;
 394 }
 395
 396 static bool i8257_is_verify_transfer(I8257Regs *r)
 397 {
 398     return (r->mode & 0x0c) == 0;
 399 }
 400
 401 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
 402                                  int len)
 403 {
 404     I8257State *d = I8257(obj);
 405     I8257Regs *r = &d->regs[nchan & 3];
 406     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 407
 408     if (i8257_is_verify_transfer(r)) {
 409         return len;
 410     }
 411
 412     if (r->mode & 0x20) {
 413         int i;
 414         uint8_t *p = buf;
 415
 416         cpu_physical_memory_read (addr - pos - len, buf, len);
 417         /* What about 16bit transfers? */
 418         for (i = 0; i < len >> 1; i++) {
 419             uint8_t b = p[len - i - 1];
 420             p[i] = b;
 421         }
 422     }
 423     else
 424         cpu_physical_memory_read (addr + pos, buf, len);
 425
 426     return len;
 427 }
 428
 429 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
 430                                  int len)
 431 {
 432     I8257State *s = I8257(obj);
 433     I8257Regs *r = &s->regs[nchan & 3];
 434     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 435
 436     if (i8257_is_verify_transfer(r)) {
 437         return len;
 438     }
 439
 440     if (r->mode & 0x20) {
 441         int i;
 442         uint8_t *p = buf;
 443
 444         cpu_physical_memory_write (addr - pos - len, buf, len);
 445         /* What about 16bit transfers? */
 446         for (i = 0; i < len; i++) {
 447             uint8_t b = p[len - i - 1];
 448             p[i] = b;
 449         }
 450     }
 451     else
 452         cpu_physical_memory_write (addr + pos, buf, len);
 453
 454     return len;
 455 }
 456
 457 /* request the emulator to transfer a new DMA memory block ASAP (even
 458  * if the idle bottom half would not have exited the iothread yet).
 459  */
 460 static void i8257_dma_schedule(IsaDma *obj)
 461 {
 462     I8257State *d = I8257(obj);
 463     if (d->dma_bh_scheduled) {
 464         qemu_notify_event();
 465     }
 466 }
 467
 468 static void i8257_reset(DeviceState *dev)
 469 {
 470     I8257State *d = I8257(dev);
 471     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
 472 }
 473
 474 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
 475                                int dma_len)
 476 {
 477     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
 478     return dma_pos;
 479 }
 480
 481
 482 static const MemoryRegionOps channel_io_ops = {
 483     .read = i8257_read_chan,
 484     .write = i8257_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 = i8257_write_page, .read = i8257_read_page, },
 495     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_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 = i8257_write_pageh, .read = i8257_read_pageh, },
 502     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
 503     PORTIO_END_OF_LIST(),
 504 };
 505
 506 static const MemoryRegionOps cont_io_ops = {
 507     .read = i8257_read_cont,
 508     .write = i8257_write_cont,
 509     .endianness = DEVICE_NATIVE_ENDIAN,
 510     .impl = {
 511         .min_access_size = 1,
 512         .max_access_size = 1,
 513     },
 514 };
 515
 516 static const VMStateDescription vmstate_i8257_regs = {
 517     .name = "dma_regs",
 518     .version_id = 1,
 519     .minimum_version_id = 1,
 520     .fields = (const VMStateField[]) {
 521         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
 522         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
 523         VMSTATE_UINT8(mode, I8257Regs),
 524         VMSTATE_UINT8(page, I8257Regs),
 525         VMSTATE_UINT8(pageh, I8257Regs),
 526         VMSTATE_UINT8(dack, I8257Regs),
 527         VMSTATE_UINT8(eop, I8257Regs),
 528         VMSTATE_END_OF_LIST()
 529     }
 530 };
 531
 532 static int i8257_post_load(void *opaque, int version_id)
 533 {
 534     I8257State *d = opaque;
 535     i8257_dma_run(d);
 536
 537     return 0;
 538 }
 539
 540 static const VMStateDescription vmstate_i8257 = {
 541     .name = "dma",
 542     .version_id = 1,
 543     .minimum_version_id = 1,
 544     .post_load = i8257_post_load,
 545     .fields = (const VMStateField[]) {
 546         VMSTATE_UINT8(command, I8257State),
 547         VMSTATE_UINT8(mask, I8257State),
 548         VMSTATE_UINT8(flip_flop, I8257State),
 549         VMSTATE_INT32(dshift, I8257State),
 550         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
 551                              I8257Regs),
 552         VMSTATE_END_OF_LIST()
 553     }
 554 };
 555
 556 static void i8257_realize(DeviceState *dev, Error **errp)
 557 {
 558     ISADevice *isa = ISA_DEVICE(dev);
 559     I8257State *d = I8257(dev);
 560     int i;
 561
 562     memory_region_init_io(&d->channel_io, OBJECT(dev), &channel_io_ops, d,
 563                           "dma-chan", 8 << d->dshift);
 564     memory_region_add_subregion(isa_address_space_io(isa),
 565                                 d->base, &d->channel_io);
 566
 567     isa_register_portio_list(isa, &d->portio_page,
 568                              d->page_base, page_portio_list, d,
 569                              "dma-page");
 570     if (d->pageh_base >= 0) {
 571         isa_register_portio_list(isa, &d->portio_pageh,
 572                                  d->pageh_base, pageh_portio_list, d,
 573                                  "dma-pageh");
 574     }
 575
 576     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
 577                           "dma-cont", 8 << d->dshift);
 578     memory_region_add_subregion(isa_address_space_io(isa),
 579                                 d->base + (8 << d->dshift), &d->cont_io);
 580
 581     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
 582         d->regs[i].transfer_handler = i8257_phony_handler;
 583     }
 584
 585     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
 586 }
 587
 588 static Property i8257_properties[] = {
 589     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
 590     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
 591     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
 592     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
 593     DEFINE_PROP_END_OF_LIST()
 594 };
 595
 596 static void i8257_class_init(ObjectClass *klass, void *data)
 597 {
 598     DeviceClass *dc = DEVICE_CLASS(klass);
 599     IsaDmaClass *idc = ISADMA_CLASS(klass);
 600
 601     dc->realize = i8257_realize;
 602     dc->reset = i8257_reset;
 603     dc->vmsd = &vmstate_i8257;
 604     device_class_set_props(dc, i8257_properties);
 605
 606     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
 607     idc->read_memory = i8257_dma_read_memory;
 608     idc->write_memory = i8257_dma_write_memory;
 609     idc->hold_DREQ = i8257_dma_hold_DREQ;
 610     idc->release_DREQ = i8257_dma_release_DREQ;
 611     idc->schedule = i8257_dma_schedule;
 612     idc->register_channel = i8257_dma_register_channel;
 613     /* Reason: needs to be wired up by isa_bus_dma() to work */
 614     dc->user_creatable = false;
 615 }
 616
 617 static const TypeInfo i8257_info = {
 618     .name = TYPE_I8257,
 619     .parent = TYPE_ISA_DEVICE,
 620     .instance_size = sizeof(I8257State),
 621     .class_init = i8257_class_init,
 622     .interfaces = (InterfaceInfo[]) {
 623         { TYPE_ISADMA },
 624         { }
 625     }
 626 };
 627
 628 static void i8257_register_types(void)
 629 {
 630     type_register_static(&i8257_info);
 631 }
 632
 633 type_init(i8257_register_types)
 634
 635 void i8257_dma_init(ISABus *bus, bool high_page_enable)
 636 {
 637     ISADevice *isa1, *isa2;
 638     DeviceState *d;
 639
 640     isa1 = isa_new(TYPE_I8257);
 641     d = DEVICE(isa1);
 642     qdev_prop_set_int32(d, "base", 0x00);
 643     qdev_prop_set_int32(d, "page-base", 0x80);
 644     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
 645     qdev_prop_set_int32(d, "dshift", 0);
 646     isa_realize_and_unref(isa1, bus, &error_fatal);
 647
 648     isa2 = isa_new(TYPE_I8257);
 649     d = DEVICE(isa2);
 650     qdev_prop_set_int32(d, "base", 0xc0);
 651     qdev_prop_set_int32(d, "page-base", 0x88);
 652     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
 653     qdev_prop_set_int32(d, "dshift", 1);
 654     isa_realize_and_unref(isa2, bus, &error_fatal);
 655
 656     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
 657 }