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 #define LENOFA(a) ((int) (sizeof(a)/sizeof(a[0])))
  41
  42 struct dma_regs {
  43     int now[2];
  44     uint16_t base[2];
  45     uint8_t mode;
  46     uint8_t page;
  47     uint8_t pageh;
  48     uint8_t dack;
  49     uint8_t eop;
  50     DMA_transfer_handler transfer_handler;
  51     void *opaque;
  52 };
  53
  54 #define ADDR 0
  55 #define COUNT 1
  56
  57 static struct dma_cont {
  58     uint8_t status;
  59     uint8_t command;
  60     uint8_t mask;
  61     uint8_t flip_flop;
  62     int dshift;
  63     struct dma_regs regs[4];
  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 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         break;
 218
 219     case 0x0a:                  /* single mask */
 220         if (data & 4)
 221             d->mask |= 1 << (data & 3);
 222         else
 223             d->mask &= ~(1 << (data & 3));
 224         break;
 225
 226     case 0x0b:                  /* mode */
 227         {
 228             ichan = data & 3;
 229 #ifdef DEBUG_DMA
 230             {
 231                 int op, ai, dir, opmode;
 232                 op = (data >> 2) & 3;
 233                 ai = (data >> 4) & 1;
 234                 dir = (data >> 5) & 1;
 235                 opmode = (data >> 6) & 3;
 236
 237                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
 238                        ichan, op, ai, dir, opmode);
 239             }
 240 #endif
 241             d->regs[ichan].mode = data;
 242             break;
 243         }
 244
 245     case 0x0c:                  /* clear flip flop */
 246         d->flip_flop = 0;
 247         break;
 248
 249     case 0x0d:                  /* reset */
 250         d->flip_flop = 0;
 251         d->mask = ~0;
 252         d->status = 0;
 253         d->command = 0;
 254         break;
 255
 256     case 0x0e:                  /* clear mask for all channels */
 257         d->mask = 0;
 258         break;
 259
 260     case 0x0f:                  /* write mask for all channels */
 261         d->mask = data;
 262         break;
 263
 264     default:
 265         dolog ("unknown iport %#x\n", iport);
 266         break;
 267     }
 268
 269 #ifdef DEBUG_DMA
 270     if (0xc != iport) {
 271         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
 272                nport, ichan, data);
 273     }
 274 #endif
 275 }
 276
 277 static uint32_t read_cont (void *opaque, uint32_t nport)
 278 {
 279     struct dma_cont *d = opaque;
 280     int iport, val;
 281
 282     iport = (nport >> d->dshift) & 0x0f;
 283     switch (iport) {
 284     case 0x08:                  /* status */
 285         val = d->status;
 286         d->status &= 0xf0;
 287         break;
 288     case 0x0f:                  /* mask */
 289         val = d->mask;
 290         break;
 291     default:
 292         val = 0;
 293         break;
 294     }
 295
 296     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
 297     return val;
 298 }
 299
 300 int DMA_get_channel_mode (int nchan)
 301 {
 302     return dma_controllers[nchan > 3].regs[nchan & 3].mode;
 303 }
 304
 305 void DMA_hold_DREQ (int nchan)
 306 {
 307     int ncont, ichan;
 308
 309     ncont = nchan > 3;
 310     ichan = nchan & 3;
 311     linfo ("held cont=%d chan=%d\n", ncont, ichan);
 312     dma_controllers[ncont].status |= 1 << (ichan + 4);
 313 }
 314
 315 void DMA_release_DREQ (int nchan)
 316 {
 317     int ncont, ichan;
 318
 319     ncont = nchan > 3;
 320     ichan = nchan & 3;
 321     linfo ("released cont=%d chan=%d\n", ncont, ichan);
 322     dma_controllers[ncont].status &= ~(1 << (ichan + 4));
 323 }
 324
 325 static void channel_run (int ncont, int ichan)
 326 {
 327     int n;
 328     struct dma_regs *r = &dma_controllers[ncont].regs[ichan];
 329 #ifdef DEBUG_DMA
 330     int dir, opmode;
 331
 332     dir = (r->mode >> 5) & 1;
 333     opmode = (r->mode >> 6) & 3;
 334
 335     if (dir) {
 336         dolog ("DMA in address decrement mode\n");
 337     }
 338     if (opmode != 1) {
 339         dolog ("DMA not in single mode select %#x\n", opmode);
 340     }
 341 #endif
 342
 343     r = dma_controllers[ncont].regs + ichan;
 344     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
 345                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
 346     r->now[COUNT] = n;
 347     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
 348 }
 349
 350 void DMA_run (void)
 351 {
 352     struct dma_cont *d;
 353     int icont, ichan;
 354
 355     d = dma_controllers;
 356
 357     for (icont = 0; icont < 2; icont++, d++) {
 358         for (ichan = 0; ichan < 4; ichan++) {
 359             int mask;
 360
 361             mask = 1 << ichan;
 362
 363             if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4))))
 364                 channel_run (icont, ichan);
 365         }
 366     }
 367 }
 368
 369 void DMA_register_channel (int nchan,
 370                            DMA_transfer_handler transfer_handler,
 371                            void *opaque)
 372 {
 373     struct dma_regs *r;
 374     int ichan, ncont;
 375
 376     ncont = nchan > 3;
 377     ichan = nchan & 3;
 378
 379     r = dma_controllers[ncont].regs + ichan;
 380     r->transfer_handler = transfer_handler;
 381     r->opaque = opaque;
 382 }
 383
 384 int DMA_read_memory (int nchan, void *buf, int pos, int len)
 385 {
 386     struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3];
 387     target_phys_addr_t addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 388
 389     if (r->mode & 0x20) {
 390         int i;
 391         uint8_t *p = buf;
 392
 393         cpu_physical_memory_read (addr - pos - len, buf, len);
 394         /* What about 16bit transfers? */
 395         for (i = 0; i < len >> 1; i++) {
 396             uint8_t b = p[len - i - 1];
 397             p[i] = b;
 398         }
 399     }
 400     else
 401         cpu_physical_memory_read (addr + pos, buf, len);
 402
 403     return len;
 404 }
 405
 406 int DMA_write_memory (int nchan, void *buf, int pos, int len)
 407 {
 408     struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3];
 409     target_phys_addr_t addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 410
 411     if (r->mode & 0x20) {
 412         int i;
 413         uint8_t *p = buf;
 414
 415         cpu_physical_memory_write (addr - pos - len, buf, len);
 416         /* What about 16bit transfers? */
 417         for (i = 0; i < len; i++) {
 418             uint8_t b = p[len - i - 1];
 419             p[i] = b;
 420         }
 421     }
 422     else
 423         cpu_physical_memory_write (addr + pos, buf, len);
 424
 425     return len;
 426 }
 427
 428 /* request the emulator to transfer a new DMA memory block ASAP */
 429 void DMA_schedule(int nchan)
 430 {
 431     CPUState *env = cpu_single_env;
 432     if (env)
 433         cpu_interrupt(env, CPU_INTERRUPT_EXIT);
 434 }
 435
 436 static void dma_reset(void *opaque)
 437 {
 438     struct dma_cont *d = opaque;
 439     write_cont (d, (0x0d << d->dshift), 0);
 440 }
 441
 442 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
 443 {
 444     dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
 445            nchan, dma_pos, dma_len);
 446     return dma_pos;
 447 }
 448
 449 /* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */
 450 static void dma_init2(struct dma_cont *d, int base, int dshift,
 451                       int page_base, int pageh_base)
 452 {
 453     static const int page_port_list[] = { 0x1, 0x2, 0x3, 0x7 };
 454     int i;
 455
 456     d->dshift = dshift;
 457     for (i = 0; i < 8; i++) {
 458         register_ioport_write (base + (i << dshift), 1, 1, write_chan, d);
 459         register_ioport_read (base + (i << dshift), 1, 1, read_chan, d);
 460     }
 461     for (i = 0; i < LENOFA (page_port_list); i++) {
 462         register_ioport_write (page_base + page_port_list[i], 1, 1,
 463                                write_page, d);
 464         register_ioport_read (page_base + page_port_list[i], 1, 1,
 465                               read_page, d);
 466         if (pageh_base >= 0) {
 467             register_ioport_write (pageh_base + page_port_list[i], 1, 1,
 468                                    write_pageh, d);
 469             register_ioport_read (pageh_base + page_port_list[i], 1, 1,
 470                                   read_pageh, d);
 471         }
 472     }
 473     for (i = 0; i < 8; i++) {
 474         register_ioport_write (base + ((i + 8) << dshift), 1, 1,
 475                                write_cont, d);
 476         register_ioport_read (base + ((i + 8) << dshift), 1, 1,
 477                               read_cont, d);
 478     }
 479     qemu_register_reset(dma_reset, d);
 480     dma_reset(d);
 481     for (i = 0; i < LENOFA (d->regs); ++i) {
 482         d->regs[i].transfer_handler = dma_phony_handler;
 483     }
 484 }
 485
 486 static void dma_save (QEMUFile *f, void *opaque)
 487 {
 488     struct dma_cont *d = opaque;
 489     int i;
 490
 491     /* qemu_put_8s (f, &d->status); */
 492     qemu_put_8s (f, &d->command);
 493     qemu_put_8s (f, &d->mask);
 494     qemu_put_8s (f, &d->flip_flop);
 495     qemu_put_be32 (f, d->dshift);
 496
 497     for (i = 0; i < 4; ++i) {
 498         struct dma_regs *r = &d->regs[i];
 499         qemu_put_be32 (f, r->now[0]);
 500         qemu_put_be32 (f, r->now[1]);
 501         qemu_put_be16s (f, &r->base[0]);
 502         qemu_put_be16s (f, &r->base[1]);
 503         qemu_put_8s (f, &r->mode);
 504         qemu_put_8s (f, &r->page);
 505         qemu_put_8s (f, &r->pageh);
 506         qemu_put_8s (f, &r->dack);
 507         qemu_put_8s (f, &r->eop);
 508     }
 509 }
 510
 511 static int dma_load (QEMUFile *f, void *opaque, int version_id)
 512 {
 513     struct dma_cont *d = opaque;
 514     int i;
 515
 516     if (version_id != 1)
 517         return -EINVAL;
 518
 519     /* qemu_get_8s (f, &d->status); */
 520     qemu_get_8s (f, &d->command);
 521     qemu_get_8s (f, &d->mask);
 522     qemu_get_8s (f, &d->flip_flop);
 523     d->dshift=qemu_get_be32 (f);
 524
 525     for (i = 0; i < 4; ++i) {
 526         struct dma_regs *r = &d->regs[i];
 527         r->now[0]=qemu_get_be32 (f);
 528         r->now[1]=qemu_get_be32 (f);
 529         qemu_get_be16s (f, &r->base[0]);
 530         qemu_get_be16s (f, &r->base[1]);
 531         qemu_get_8s (f, &r->mode);
 532         qemu_get_8s (f, &r->page);
 533         qemu_get_8s (f, &r->pageh);
 534         qemu_get_8s (f, &r->dack);
 535         qemu_get_8s (f, &r->eop);
 536     }
 537     return 0;
 538 }
 539
 540 void DMA_init (int high_page_enable)
 541 {
 542     dma_init2(&dma_controllers[0], 0x00, 0, 0x80,
 543               high_page_enable ? 0x480 : -1);
 544     dma_init2(&dma_controllers[1], 0xc0, 1, 0x88,
 545               high_page_enable ? 0x488 : -1);
 546     register_savevm ("dma", 0, 1, dma_save, dma_load, &dma_controllers[0]);
 547     register_savevm ("dma", 1, 1, dma_save, dma_load, &dma_controllers[1]);
 548 }