hw/dma.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 "hw.h"
  25 #include "isa.h"
  26
  27 /* #define DEBUG_DMA */
  28
  29 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
  30 #ifdef DEBUG_DMA
  31 #define lwarn(...) fprintf (stderr, "dma: " __VA_ARGS__)
  32 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
  33 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
  34 #else
  35 #define lwarn(...)
  36 #define linfo(...)
  37 #define ldebug(...)
  38 #endif
  39
  40 struct dma_regs {
  41     int now[2];
  42     uint16_t base[2];
  43     uint8_t mode;
  44     uint8_t page;
  45     uint8_t pageh;
  46     uint8_t dack;
  47     uint8_t eop;
  48     DMA_transfer_handler transfer_handler;
  49     void *opaque;
  50 };
  51
  52 #define ADDR 0
  53 #define COUNT 1
  54
  55 static struct dma_cont {
  56     uint8_t status;
  57     uint8_t command;
  58     uint8_t mask;
  59     uint8_t flip_flop;
  60     int dshift;
  61     struct dma_regs regs[4];
  62 } dma_controllers[2];
  63
  64 enum {
  65     CMD_MEMORY_TO_MEMORY = 0x01,
  66     CMD_FIXED_ADDRESS    = 0x02,
  67     CMD_BLOCK_CONTROLLER = 0x04,
  68     CMD_COMPRESSED_TIME  = 0x08,
  69     CMD_CYCLIC_PRIORITY  = 0x10,
  70     CMD_EXTENDED_WRITE   = 0x20,
  71     CMD_LOW_DREQ         = 0x40,
  72     CMD_LOW_DACK         = 0x80,
  73     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
  74     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
  75     | CMD_LOW_DREQ | CMD_LOW_DACK
  76
  77 };
  78
  79 static void DMA_run (void);
  80
  81 static int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
  82
  83 static void write_page (void *opaque, uint32_t nport, uint32_t data)
  84 {
  85     struct dma_cont *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].page = data;
  94 }
  95
  96 static void write_pageh (void *opaque, uint32_t nport, uint32_t data)
  97 {
  98     struct dma_cont *d = opaque;
  99     int ichan;
 100
 101     ichan = channels[nport & 7];
 102     if (-1 == ichan) {
 103         dolog ("invalid channel %#x %#x\n", nport, data);
 104         return;
 105     }
 106     d->regs[ichan].pageh = data;
 107 }
 108
 109 static uint32_t read_page (void *opaque, uint32_t nport)
 110 {
 111     struct dma_cont *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].page;
 120 }
 121
 122 static uint32_t read_pageh (void *opaque, uint32_t nport)
 123 {
 124     struct dma_cont *d = opaque;
 125     int ichan;
 126
 127     ichan = channels[nport & 7];
 128     if (-1 == ichan) {
 129         dolog ("invalid channel read %#x\n", nport);
 130         return 0;
 131     }
 132     return d->regs[ichan].pageh;
 133 }
 134
 135 static inline void init_chan (struct dma_cont *d, int ichan)
 136 {
 137     struct dma_regs *r;
 138
 139     r = d->regs + ichan;
 140     r->now[ADDR] = r->base[ADDR] << d->dshift;
 141     r->now[COUNT] = 0;
 142 }
 143
 144 static inline int getff (struct dma_cont *d)
 145 {
 146     int ff;
 147
 148     ff = d->flip_flop;
 149     d->flip_flop = !ff;
 150     return ff;
 151 }
 152
 153 static uint32_t read_chan (void *opaque, uint32_t nport)
 154 {
 155     struct dma_cont *d = opaque;
 156     int ichan, nreg, iport, ff, val, dir;
 157     struct dma_regs *r;
 158
 159     iport = (nport >> d->dshift) & 0x0f;
 160     ichan = iport >> 1;
 161     nreg = iport & 1;
 162     r = d->regs + ichan;
 163
 164     dir = ((r->mode >> 5) & 1) ? -1 : 1;
 165     ff = getff (d);
 166     if (nreg)
 167         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
 168     else
 169         val = r->now[ADDR] + r->now[COUNT] * dir;
 170
 171     ldebug ("read_chan %#x -> %d\n", iport, val);
 172     return (val >> (d->dshift + (ff << 3))) & 0xff;
 173 }
 174
 175 static void write_chan (void *opaque, uint32_t nport, uint32_t data)
 176 {
 177     struct dma_cont *d = opaque;
 178     int iport, ichan, nreg;
 179     struct dma_regs *r;
 180
 181     iport = (nport >> d->dshift) & 0x0f;
 182     ichan = iport >> 1;
 183     nreg = iport & 1;
 184     r = d->regs + ichan;
 185     if (getff (d)) {
 186         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
 187         init_chan (d, ichan);
 188     } else {
 189         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
 190     }
 191 }
 192
 193 static void write_cont (void *opaque, uint32_t nport, uint32_t data)
 194 {
 195     struct dma_cont *d = opaque;
 196     int iport, ichan = 0;
 197
 198     iport = (nport >> d->dshift) & 0x0f;
 199     switch (iport) {
 200     case 0x08:                  /* command */
 201         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
 202             dolog ("command %#x not supported\n", data);
 203             return;
 204         }
 205         d->command = data;
 206         break;
 207
 208     case 0x09:
 209         ichan = data & 3;
 210         if (data & 4) {
 211             d->status |= 1 << (ichan + 4);
 212         }
 213         else {
 214             d->status &= ~(1 << (ichan + 4));
 215         }
 216         d->status &= ~(1 << ichan);
 217         DMA_run();
 218         break;
 219
 220     case 0x0a:                  /* single mask */
 221         if (data & 4)
 222             d->mask |= 1 << (data & 3);
 223         else
 224             d->mask &= ~(1 << (data & 3));
 225         DMA_run();
 226         break;
 227
 228     case 0x0b:                  /* mode */
 229         {
 230             ichan = data & 3;
 231 #ifdef DEBUG_DMA
 232             {
 233                 int op, ai, dir, opmode;
 234                 op = (data >> 2) & 3;
 235                 ai = (data >> 4) & 1;
 236                 dir = (data >> 5) & 1;
 237                 opmode = (data >> 6) & 3;
 238
 239                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
 240                        ichan, op, ai, dir, opmode);
 241             }
 242 #endif
 243             d->regs[ichan].mode = data;
 244             break;
 245         }
 246
 247     case 0x0c:                  /* clear flip flop */
 248         d->flip_flop = 0;
 249         break;
 250
 251     case 0x0d:                  /* reset */
 252         d->flip_flop = 0;
 253         d->mask = ~0;
 254         d->status = 0;
 255         d->command = 0;
 256         break;
 257
 258     case 0x0e:                  /* clear mask for all channels */
 259         d->mask = 0;
 260         DMA_run();
 261         break;
 262
 263     case 0x0f:                  /* write mask for all channels */
 264         d->mask = data;
 265         DMA_run();
 266         break;
 267
 268     default:
 269         dolog ("unknown iport %#x\n", iport);
 270         break;
 271     }
 272
 273 #ifdef DEBUG_DMA
 274     if (0xc != iport) {
 275         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
 276                nport, ichan, data);
 277     }
 278 #endif
 279 }
 280
 281 static uint32_t read_cont (void *opaque, uint32_t nport)
 282 {
 283     struct dma_cont *d = opaque;
 284     int iport, val;
 285
 286     iport = (nport >> d->dshift) & 0x0f;
 287     switch (iport) {
 288     case 0x08:                  /* status */
 289         val = d->status;
 290         d->status &= 0xf0;
 291         break;
 292     case 0x0f:                  /* mask */
 293         val = d->mask;
 294         break;
 295     default:
 296         val = 0;
 297         break;
 298     }
 299
 300     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
 301     return val;
 302 }
 303
 304 int DMA_get_channel_mode (int nchan)
 305 {
 306     return dma_controllers[nchan > 3].regs[nchan & 3].mode;
 307 }
 308
 309 void DMA_hold_DREQ (int nchan)
 310 {
 311     int ncont, ichan;
 312
 313     ncont = nchan > 3;
 314     ichan = nchan & 3;
 315     linfo ("held cont=%d chan=%d\n", ncont, ichan);
 316     dma_controllers[ncont].status |= 1 << (ichan + 4);
 317     DMA_run();
 318 }
 319
 320 void DMA_release_DREQ (int nchan)
 321 {
 322     int ncont, ichan;
 323
 324     ncont = nchan > 3;
 325     ichan = nchan & 3;
 326     linfo ("released cont=%d chan=%d\n", ncont, ichan);
 327     dma_controllers[ncont].status &= ~(1 << (ichan + 4));
 328     DMA_run();
 329 }
 330
 331 static void channel_run (int ncont, int ichan)
 332 {
 333     int n;
 334     struct dma_regs *r = &dma_controllers[ncont].regs[ichan];
 335 #ifdef DEBUG_DMA
 336     int dir, opmode;
 337
 338     dir = (r->mode >> 5) & 1;
 339     opmode = (r->mode >> 6) & 3;
 340
 341     if (dir) {
 342         dolog ("DMA in address decrement mode\n");
 343     }
 344     if (opmode != 1) {
 345         dolog ("DMA not in single mode select %#x\n", opmode);
 346     }
 347 #endif
 348
 349     r = dma_controllers[ncont].regs + ichan;
 350     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
 351                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
 352     r->now[COUNT] = n;
 353     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
 354 }
 355
 356 static QEMUBH *dma_bh;
 357
 358 static void DMA_run (void)
 359 {
 360     struct dma_cont *d;
 361     int icont, ichan;
 362     int rearm = 0;
 363
 364     d = dma_controllers;
 365
 366     for (icont = 0; icont < 2; icont++, d++) {
 367         for (ichan = 0; ichan < 4; ichan++) {
 368             int mask;
 369
 370             mask = 1 << ichan;
 371
 372             if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
 373                 channel_run (icont, ichan);
 374                 rearm = 1;
 375             }
 376         }
 377     }
 378
 379     if (rearm)
 380         qemu_bh_schedule_idle(dma_bh);
 381 }
 382
 383 static void DMA_run_bh(void *unused)
 384 {
 385     DMA_run();
 386 }
 387
 388 void DMA_register_channel (int nchan,
 389                            DMA_transfer_handler transfer_handler,
 390                            void *opaque)
 391 {
 392     struct dma_regs *r;
 393     int ichan, ncont;
 394
 395     ncont = nchan > 3;
 396     ichan = nchan & 3;
 397
 398     r = dma_controllers[ncont].regs + ichan;
 399     r->transfer_handler = transfer_handler;
 400     r->opaque = opaque;
 401 }
 402
 403 int DMA_read_memory (int nchan, void *buf, int pos, int len)
 404 {
 405     struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3];
 406     target_phys_addr_t addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 407
 408     if (r->mode & 0x20) {
 409         int i;
 410         uint8_t *p = buf;
 411
 412         cpu_physical_memory_read (addr - pos - len, buf, len);
 413         /* What about 16bit transfers? */
 414         for (i = 0; i < len >> 1; i++) {
 415             uint8_t b = p[len - i - 1];
 416             p[i] = b;
 417         }
 418     }
 419     else
 420         cpu_physical_memory_read (addr + pos, buf, len);
 421
 422     return len;
 423 }
 424
 425 int DMA_write_memory (int nchan, void *buf, int pos, int len)
 426 {
 427     struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3];
 428     target_phys_addr_t addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 429
 430     if (r->mode & 0x20) {
 431         int i;
 432         uint8_t *p = buf;
 433
 434         cpu_physical_memory_write (addr - pos - len, buf, len);
 435         /* What about 16bit transfers? */
 436         for (i = 0; i < len; i++) {
 437             uint8_t b = p[len - i - 1];
 438             p[i] = b;
 439         }
 440     }
 441     else
 442         cpu_physical_memory_write (addr + pos, buf, len);
 443
 444     return len;
 445 }
 446
 447 /* request the emulator to transfer a new DMA memory block ASAP */
 448 void DMA_schedule(int nchan)
 449 {
 450     CPUState *env = cpu_single_env;
 451     if (env)
 452         cpu_interrupt(env, CPU_INTERRUPT_EXIT);
 453 }
 454
 455 static void dma_reset(void *opaque)
 456 {
 457     struct dma_cont *d = opaque;
 458     write_cont (d, (0x0d << d->dshift), 0);
 459 }
 460
 461 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
 462 {
 463     dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
 464            nchan, dma_pos, dma_len);
 465     return dma_pos;
 466 }
 467
 468 /* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */
 469 static void dma_init2(struct dma_cont *d, int base, int dshift,
 470                       int page_base, int pageh_base)
 471 {
 472     static const int page_port_list[] = { 0x1, 0x2, 0x3, 0x7 };
 473     int i;
 474
 475     d->dshift = dshift;
 476     for (i = 0; i < 8; i++) {
 477         register_ioport_write (base + (i << dshift), 1, 1, write_chan, d);
 478         register_ioport_read (base + (i << dshift), 1, 1, read_chan, d);
 479     }
 480     for (i = 0; i < ARRAY_SIZE (page_port_list); i++) {
 481         register_ioport_write (page_base + page_port_list[i], 1, 1,
 482                                write_page, d);
 483         register_ioport_read (page_base + page_port_list[i], 1, 1,
 484                               read_page, d);
 485         if (pageh_base >= 0) {
 486             register_ioport_write (pageh_base + page_port_list[i], 1, 1,
 487                                    write_pageh, d);
 488             register_ioport_read (pageh_base + page_port_list[i], 1, 1,
 489                                   read_pageh, d);
 490         }
 491     }
 492     for (i = 0; i < 8; i++) {
 493         register_ioport_write (base + ((i + 8) << dshift), 1, 1,
 494                                write_cont, d);
 495         register_ioport_read (base + ((i + 8) << dshift), 1, 1,
 496                               read_cont, d);
 497     }
 498     qemu_register_reset(dma_reset, d);
 499     dma_reset(d);
 500     for (i = 0; i < ARRAY_SIZE (d->regs); ++i) {
 501         d->regs[i].transfer_handler = dma_phony_handler;
 502     }
 503 }
 504
 505 static void dma_save (QEMUFile *f, void *opaque)
 506 {
 507     struct dma_cont *d = opaque;
 508     int i;
 509
 510     /* qemu_put_8s (f, &d->status); */
 511     qemu_put_8s (f, &d->command);
 512     qemu_put_8s (f, &d->mask);
 513     qemu_put_8s (f, &d->flip_flop);
 514     qemu_put_be32 (f, d->dshift);
 515
 516     for (i = 0; i < 4; ++i) {
 517         struct dma_regs *r = &d->regs[i];
 518         qemu_put_be32 (f, r->now[0]);
 519         qemu_put_be32 (f, r->now[1]);
 520         qemu_put_be16s (f, &r->base[0]);
 521         qemu_put_be16s (f, &r->base[1]);
 522         qemu_put_8s (f, &r->mode);
 523         qemu_put_8s (f, &r->page);
 524         qemu_put_8s (f, &r->pageh);
 525         qemu_put_8s (f, &r->dack);
 526         qemu_put_8s (f, &r->eop);
 527     }
 528 }
 529
 530 static int dma_load (QEMUFile *f, void *opaque, int version_id)
 531 {
 532     struct dma_cont *d = opaque;
 533     int i;
 534
 535     if (version_id != 1)
 536         return -EINVAL;
 537
 538     /* qemu_get_8s (f, &d->status); */
 539     qemu_get_8s (f, &d->command);
 540     qemu_get_8s (f, &d->mask);
 541     qemu_get_8s (f, &d->flip_flop);
 542     d->dshift=qemu_get_be32 (f);
 543
 544     for (i = 0; i < 4; ++i) {
 545         struct dma_regs *r = &d->regs[i];
 546         r->now[0]=qemu_get_be32 (f);
 547         r->now[1]=qemu_get_be32 (f);
 548         qemu_get_be16s (f, &r->base[0]);
 549         qemu_get_be16s (f, &r->base[1]);
 550         qemu_get_8s (f, &r->mode);
 551         qemu_get_8s (f, &r->page);
 552         qemu_get_8s (f, &r->pageh);
 553         qemu_get_8s (f, &r->dack);
 554         qemu_get_8s (f, &r->eop);
 555     }
 556
 557     DMA_run();
 558
 559     return 0;
 560 }
 561
 562 void DMA_init (int high_page_enable)
 563 {
 564     dma_init2(&dma_controllers[0], 0x00, 0, 0x80,
 565               high_page_enable ? 0x480 : -1);
 566     dma_init2(&dma_controllers[1], 0xc0, 1, 0x88,
 567               high_page_enable ? 0x488 : -1);
 568     register_savevm ("dma", 0, 1, dma_save, dma_load, &dma_controllers[0]);
 569     register_savevm ("dma", 1, 1, dma_save, dma_load, &dma_controllers[1]);
 570
 571     dma_bh = qemu_bh_new(DMA_run_bh, NULL);
 572 }