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 linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
  32 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
  33 #else
  34 #define linfo(...)
  35 #define ldebug(...)
  36 #endif
  37
  38 struct dma_regs {
  39     int now[2];
  40     uint16_t base[2];
  41     uint8_t mode;
  42     uint8_t page;
  43     uint8_t pageh;
  44     uint8_t dack;
  45     uint8_t eop;
  46     DMA_transfer_handler transfer_handler;
  47     void *opaque;
  48 };
  49
  50 #define ADDR 0
  51 #define COUNT 1
  52
  53 static struct dma_cont {
  54     uint8_t status;
  55     uint8_t command;
  56     uint8_t mask;
  57     uint8_t flip_flop;
  58     int dshift;
  59     struct dma_regs regs[4];
  60 } dma_controllers[2];
  61
  62 enum {
  63     CMD_MEMORY_TO_MEMORY = 0x01,
  64     CMD_FIXED_ADDRESS    = 0x02,
  65     CMD_BLOCK_CONTROLLER = 0x04,
  66     CMD_COMPRESSED_TIME  = 0x08,
  67     CMD_CYCLIC_PRIORITY  = 0x10,
  68     CMD_EXTENDED_WRITE   = 0x20,
  69     CMD_LOW_DREQ         = 0x40,
  70     CMD_LOW_DACK         = 0x80,
  71     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
  72     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
  73     | CMD_LOW_DREQ | CMD_LOW_DACK
  74
  75 };
  76
  77 static void DMA_run (void);
  78
  79 static int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
  80
  81 static void write_page (void *opaque, uint32_t nport, uint32_t data)
  82 {
  83     struct dma_cont *d = opaque;
  84     int ichan;
  85
  86     ichan = channels[nport & 7];
  87     if (-1 == ichan) {
  88         dolog ("invalid channel %#x %#x\n", nport, data);
  89         return;
  90     }
  91     d->regs[ichan].page = data;
  92 }
  93
  94 static void write_pageh (void *opaque, uint32_t nport, uint32_t data)
  95 {
  96     struct dma_cont *d = opaque;
  97     int ichan;
  98
  99     ichan = channels[nport & 7];
 100     if (-1 == ichan) {
 101         dolog ("invalid channel %#x %#x\n", nport, data);
 102         return;
 103     }
 104     d->regs[ichan].pageh = data;
 105 }
 106
 107 static uint32_t read_page (void *opaque, uint32_t nport)
 108 {
 109     struct dma_cont *d = opaque;
 110     int ichan;
 111
 112     ichan = channels[nport & 7];
 113     if (-1 == ichan) {
 114         dolog ("invalid channel read %#x\n", nport);
 115         return 0;
 116     }
 117     return d->regs[ichan].page;
 118 }
 119
 120 static uint32_t read_pageh (void *opaque, uint32_t nport)
 121 {
 122     struct dma_cont *d = opaque;
 123     int ichan;
 124
 125     ichan = channels[nport & 7];
 126     if (-1 == ichan) {
 127         dolog ("invalid channel read %#x\n", nport);
 128         return 0;
 129     }
 130     return d->regs[ichan].pageh;
 131 }
 132
 133 static inline void init_chan (struct dma_cont *d, int ichan)
 134 {
 135     struct dma_regs *r;
 136
 137     r = d->regs + ichan;
 138     r->now[ADDR] = r->base[ADDR] << d->dshift;
 139     r->now[COUNT] = 0;
 140 }
 141
 142 static inline int getff (struct dma_cont *d)
 143 {
 144     int ff;
 145
 146     ff = d->flip_flop;
 147     d->flip_flop = !ff;
 148     return ff;
 149 }
 150
 151 static uint32_t read_chan (void *opaque, uint32_t nport)
 152 {
 153     struct dma_cont *d = opaque;
 154     int ichan, nreg, iport, ff, val, dir;
 155     struct dma_regs *r;
 156
 157     iport = (nport >> d->dshift) & 0x0f;
 158     ichan = iport >> 1;
 159     nreg = iport & 1;
 160     r = d->regs + ichan;
 161
 162     dir = ((r->mode >> 5) & 1) ? -1 : 1;
 163     ff = getff (d);
 164     if (nreg)
 165         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
 166     else
 167         val = r->now[ADDR] + r->now[COUNT] * dir;
 168
 169     ldebug ("read_chan %#x -> %d\n", iport, val);
 170     return (val >> (d->dshift + (ff << 3))) & 0xff;
 171 }
 172
 173 static void write_chan (void *opaque, uint32_t nport, uint32_t data)
 174 {
 175     struct dma_cont *d = opaque;
 176     int iport, ichan, nreg;
 177     struct dma_regs *r;
 178
 179     iport = (nport >> d->dshift) & 0x0f;
 180     ichan = iport >> 1;
 181     nreg = iport & 1;
 182     r = d->regs + ichan;
 183     if (getff (d)) {
 184         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
 185         init_chan (d, ichan);
 186     } else {
 187         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
 188     }
 189 }
 190
 191 static void write_cont (void *opaque, uint32_t nport, uint32_t data)
 192 {
 193     struct dma_cont *d = opaque;
 194     int iport, ichan = 0;
 195
 196     iport = (nport >> d->dshift) & 0x0f;
 197     switch (iport) {
 198     case 0x08:                  /* command */
 199         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
 200             dolog ("command %#x not supported\n", data);
 201             return;
 202         }
 203         d->command = data;
 204         break;
 205
 206     case 0x09:
 207         ichan = data & 3;
 208         if (data & 4) {
 209             d->status |= 1 << (ichan + 4);
 210         }
 211         else {
 212             d->status &= ~(1 << (ichan + 4));
 213         }
 214         d->status &= ~(1 << ichan);
 215         DMA_run();
 216         break;
 217
 218     case 0x0a:                  /* single mask */
 219         if (data & 4)
 220             d->mask |= 1 << (data & 3);
 221         else
 222             d->mask &= ~(1 << (data & 3));
 223         DMA_run();
 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         DMA_run();
 259         break;
 260
 261     case 0x0f:                  /* write mask for all channels */
 262         d->mask = data;
 263         DMA_run();
 264         break;
 265
 266     default:
 267         dolog ("unknown iport %#x\n", iport);
 268         break;
 269     }
 270
 271 #ifdef DEBUG_DMA
 272     if (0xc != iport) {
 273         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
 274                nport, ichan, data);
 275     }
 276 #endif
 277 }
 278
 279 static uint32_t read_cont (void *opaque, uint32_t nport)
 280 {
 281     struct dma_cont *d = opaque;
 282     int iport, val;
 283
 284     iport = (nport >> d->dshift) & 0x0f;
 285     switch (iport) {
 286     case 0x08:                  /* status */
 287         val = d->status;
 288         d->status &= 0xf0;
 289         break;
 290     case 0x0f:                  /* mask */
 291         val = d->mask;
 292         break;
 293     default:
 294         val = 0;
 295         break;
 296     }
 297
 298     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
 299     return val;
 300 }
 301
 302 int DMA_get_channel_mode (int nchan)
 303 {
 304     return dma_controllers[nchan > 3].regs[nchan & 3].mode;
 305 }
 306
 307 void DMA_hold_DREQ (int nchan)
 308 {
 309     int ncont, ichan;
 310
 311     ncont = nchan > 3;
 312     ichan = nchan & 3;
 313     linfo ("held cont=%d chan=%d\n", ncont, ichan);
 314     dma_controllers[ncont].status |= 1 << (ichan + 4);
 315     DMA_run();
 316 }
 317
 318 void DMA_release_DREQ (int nchan)
 319 {
 320     int ncont, ichan;
 321
 322     ncont = nchan > 3;
 323     ichan = nchan & 3;
 324     linfo ("released cont=%d chan=%d\n", ncont, ichan);
 325     dma_controllers[ncont].status &= ~(1 << (ichan + 4));
 326     DMA_run();
 327 }
 328
 329 static void channel_run (int ncont, int ichan)
 330 {
 331     int n;
 332     struct dma_regs *r = &dma_controllers[ncont].regs[ichan];
 333 #ifdef DEBUG_DMA
 334     int dir, opmode;
 335
 336     dir = (r->mode >> 5) & 1;
 337     opmode = (r->mode >> 6) & 3;
 338
 339     if (dir) {
 340         dolog ("DMA in address decrement mode\n");
 341     }
 342     if (opmode != 1) {
 343         dolog ("DMA not in single mode select %#x\n", opmode);
 344     }
 345 #endif
 346
 347     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
 348                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
 349     r->now[COUNT] = n;
 350     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
 351 }
 352
 353 static QEMUBH *dma_bh;
 354
 355 static void DMA_run (void)
 356 {
 357     struct dma_cont *d;
 358     int icont, ichan;
 359     int rearm = 0;
 360
 361     d = dma_controllers;
 362
 363     for (icont = 0; icont < 2; icont++, d++) {
 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                 channel_run (icont, ichan);
 371                 rearm = 1;
 372             }
 373         }
 374     }
 375
 376     if (rearm)
 377         qemu_bh_schedule_idle(dma_bh);
 378 }
 379
 380 static void DMA_run_bh(void *unused)
 381 {
 382     DMA_run();
 383 }
 384
 385 void DMA_register_channel (int nchan,
 386                            DMA_transfer_handler transfer_handler,
 387                            void *opaque)
 388 {
 389     struct dma_regs *r;
 390     int ichan, ncont;
 391
 392     ncont = nchan > 3;
 393     ichan = nchan & 3;
 394
 395     r = dma_controllers[ncont].regs + ichan;
 396     r->transfer_handler = transfer_handler;
 397     r->opaque = opaque;
 398 }
 399
 400 int DMA_read_memory (int nchan, void *buf, int pos, int len)
 401 {
 402     struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3];
 403     target_phys_addr_t 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 int DMA_write_memory (int nchan, void *buf, int pos, int len)
 423 {
 424     struct dma_regs *r = &dma_controllers[nchan > 3].regs[nchan & 3];
 425     target_phys_addr_t addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
 426
 427     if (r->mode & 0x20) {
 428         int i;
 429         uint8_t *p = buf;
 430
 431         cpu_physical_memory_write (addr - pos - len, buf, len);
 432         /* What about 16bit transfers? */
 433         for (i = 0; i < len; i++) {
 434             uint8_t b = p[len - i - 1];
 435             p[i] = b;
 436         }
 437     }
 438     else
 439         cpu_physical_memory_write (addr + pos, buf, len);
 440
 441     return len;
 442 }
 443
 444 /* request the emulator to transfer a new DMA memory block ASAP */
 445 void DMA_schedule(int nchan)
 446 {
 447     CPUState *env = cpu_single_env;
 448     if (env)
 449         cpu_exit(env);
 450 }
 451
 452 static void dma_reset(void *opaque)
 453 {
 454     struct dma_cont *d = opaque;
 455     write_cont (d, (0x0d << d->dshift), 0);
 456 }
 457
 458 static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
 459 {
 460     dolog ("unregistered DMA channel used nchan=%d dma_pos=%d dma_len=%d\n",
 461            nchan, dma_pos, dma_len);
 462     return dma_pos;
 463 }
 464
 465 /* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */
 466 static void dma_init2(struct dma_cont *d, int base, int dshift,
 467                       int page_base, int pageh_base)
 468 {
 469     static const int page_port_list[] = { 0x1, 0x2, 0x3, 0x7 };
 470     int i;
 471
 472     d->dshift = dshift;
 473     for (i = 0; i < 8; i++) {
 474         register_ioport_write (base + (i << dshift), 1, 1, write_chan, d);
 475         register_ioport_read (base + (i << dshift), 1, 1, read_chan, d);
 476     }
 477     for (i = 0; i < ARRAY_SIZE (page_port_list); i++) {
 478         register_ioport_write (page_base + page_port_list[i], 1, 1,
 479                                write_page, d);
 480         register_ioport_read (page_base + page_port_list[i], 1, 1,
 481                               read_page, d);
 482         if (pageh_base >= 0) {
 483             register_ioport_write (pageh_base + page_port_list[i], 1, 1,
 484                                    write_pageh, d);
 485             register_ioport_read (pageh_base + page_port_list[i], 1, 1,
 486                                   read_pageh, d);
 487         }
 488     }
 489     for (i = 0; i < 8; i++) {
 490         register_ioport_write (base + ((i + 8) << dshift), 1, 1,
 491                                write_cont, d);
 492         register_ioport_read (base + ((i + 8) << dshift), 1, 1,
 493                               read_cont, d);
 494     }
 495     qemu_register_reset(dma_reset, d);
 496     dma_reset(d);
 497     for (i = 0; i < ARRAY_SIZE (d->regs); ++i) {
 498         d->regs[i].transfer_handler = dma_phony_handler;
 499     }
 500 }
 501
 502 static const VMStateDescription vmstate_dma_regs = {
 503     .name = "dma_regs",
 504     .version_id = 1,
 505     .minimum_version_id = 1,
 506     .minimum_version_id_old = 1,
 507     .fields      = (VMStateField []) {
 508         VMSTATE_INT32_ARRAY(now, struct dma_regs, 2),
 509         VMSTATE_UINT16_ARRAY(base, struct dma_regs, 2),
 510         VMSTATE_UINT8(mode, struct dma_regs),
 511         VMSTATE_UINT8(page, struct dma_regs),
 512         VMSTATE_UINT8(pageh, struct dma_regs),
 513         VMSTATE_UINT8(dack, struct dma_regs),
 514         VMSTATE_UINT8(eop, struct dma_regs),
 515         VMSTATE_END_OF_LIST()
 516     }
 517 };
 518
 519 static int dma_post_load(void *opaque, int version_id)
 520 {
 521     DMA_run();
 522
 523     return 0;
 524 }
 525
 526 static const VMStateDescription vmstate_dma = {
 527     .name = "dma",
 528     .version_id = 1,
 529     .minimum_version_id = 1,
 530     .minimum_version_id_old = 1,
 531     .post_load = dma_post_load,
 532     .fields      = (VMStateField []) {
 533         VMSTATE_UINT8(command, struct dma_cont),
 534         VMSTATE_UINT8(mask, struct dma_cont),
 535         VMSTATE_UINT8(flip_flop, struct dma_cont),
 536         VMSTATE_INT32(dshift, struct dma_cont),
 537         VMSTATE_STRUCT_ARRAY(regs, struct dma_cont, 4, 1, vmstate_dma_regs, struct dma_regs),
 538         VMSTATE_END_OF_LIST()
 539     }
 540 };
 541
 542 void DMA_init (int high_page_enable)
 543 {
 544     dma_init2(&dma_controllers[0], 0x00, 0, 0x80,
 545               high_page_enable ? 0x480 : -1);
 546     dma_init2(&dma_controllers[1], 0xc0, 1, 0x88,
 547               high_page_enable ? 0x488 : -1);
 548     vmstate_register (0, &vmstate_dma, &dma_controllers[0]);
 549     vmstate_register (1, &vmstate_dma, &dma_controllers[1]);
 550
 551     dma_bh = qemu_bh_new(DMA_run_bh, NULL);
 552 }