hw/mac_dbdma.c

   1 /*
   2  * PowerMac descriptor-based DMA emulation
   3  *
   4  * Copyright (c) 2005-2007 Fabrice Bellard
   5  * Copyright (c) 2007 Jocelyn Mayer
   6  * Copyright (c) 2009 Laurent Vivier
   7  *
   8  * some parts from linux-2.6.28, arch/powerpc/include/asm/dbdma.h
   9  *
  10  *   Definitions for using the Apple Descriptor-Based DMA controller
  11  *   in Power Macintosh computers.
  12  *
  13  *   Copyright (C) 1996 Paul Mackerras.
  14  *
  15  * some parts from mol 0.9.71
  16  *
  17  *   Descriptor based DMA emulation
  18  *
  19  *   Copyright (C) 1998-2004 Samuel Rydh (samuel@ibrium.se)
  20  *
  21  * Permission is hereby granted, free of charge, to any person obtaining a copy
  22  * of this software and associated documentation files (the "Software"), to deal
  23  * in the Software without restriction, including without limitation the rights
  24  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  25  * copies of the Software, and to permit persons to whom the Software is
  26  * furnished to do so, subject to the following conditions:
  27  *
  28  * The above copyright notice and this permission notice shall be included in
  29  * all copies or substantial portions of the Software.
  30  *
  31  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  32  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  33  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  34  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  35  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  36  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  37  * THE SOFTWARE.
  38  */
  39 #include "hw.h"
  40 #include "isa.h"
  41 #include "mac_dbdma.h"
  42
  43 /* debug DBDMA */
  44 //#define DEBUG_DBDMA
  45
  46 #ifdef DEBUG_DBDMA
  47 #define DBDMA_DPRINTF(fmt, ...)                                 \
  48     do { printf("DBDMA: " fmt , ## __VA_ARGS__); } while (0)
  49 #else
  50 #define DBDMA_DPRINTF(fmt, ...)
  51 #endif
  52
  53 /*
  54  */
  55
  56 /*
  57  * DBDMA control/status registers.  All little-endian.
  58  */
  59
  60 #define DBDMA_CONTROL         0x00
  61 #define DBDMA_STATUS          0x01
  62 #define DBDMA_CMDPTR_HI       0x02
  63 #define DBDMA_CMDPTR_LO       0x03
  64 #define DBDMA_INTR_SEL        0x04
  65 #define DBDMA_BRANCH_SEL      0x05
  66 #define DBDMA_WAIT_SEL        0x06
  67 #define DBDMA_XFER_MODE       0x07
  68 #define DBDMA_DATA2PTR_HI     0x08
  69 #define DBDMA_DATA2PTR_LO     0x09
  70 #define DBDMA_RES1            0x0A
  71 #define DBDMA_ADDRESS_HI      0x0B
  72 #define DBDMA_BRANCH_ADDR_HI  0x0C
  73 #define DBDMA_RES2            0x0D
  74 #define DBDMA_RES3            0x0E
  75 #define DBDMA_RES4            0x0F
  76
  77 #define DBDMA_REGS            16
  78 #define DBDMA_SIZE            (DBDMA_REGS * sizeof(uint32_t))
  79
  80 #define DBDMA_CHANNEL_SHIFT   7
  81 #define DBDMA_CHANNEL_SIZE    (1 << DBDMA_CHANNEL_SHIFT)
  82
  83 #define DBDMA_CHANNELS        (0x1000 >> DBDMA_CHANNEL_SHIFT)
  84
  85 /* Bits in control and status registers */
  86
  87 #define RUN     0x8000
  88 #define PAUSE   0x4000
  89 #define FLUSH   0x2000
  90 #define WAKE    0x1000
  91 #define DEAD    0x0800
  92 #define ACTIVE  0x0400
  93 #define BT      0x0100
  94 #define DEVSTAT 0x00ff
  95
  96 /*
  97  * DBDMA command structure.  These fields are all little-endian!
  98  */
  99
 100 typedef struct dbdma_cmd {
 101     uint16_t req_count;   /* requested byte transfer count */
 102     uint16_t command;     /* command word (has bit-fields) */
 103     uint32_t phy_addr;    /* physical data address */
 104     uint32_t cmd_dep;     /* command-dependent field */
 105     uint16_t res_count;   /* residual count after completion */
 106     uint16_t xfer_status; /* transfer status */
 107 } dbdma_cmd;
 108
 109 /* DBDMA command values in command field */
 110
 111 #define COMMAND_MASK    0xf000
 112 #define OUTPUT_MORE     0x0000  /* transfer memory data to stream */
 113 #define OUTPUT_LAST     0x1000  /* ditto followed by end marker */
 114 #define INPUT_MORE      0x2000  /* transfer stream data to memory */
 115 #define INPUT_LAST      0x3000  /* ditto, expect end marker */
 116 #define STORE_WORD      0x4000  /* write word (4 bytes) to device reg */
 117 #define LOAD_WORD       0x5000  /* read word (4 bytes) from device reg */
 118 #define DBDMA_NOP       0x6000  /* do nothing */
 119 #define DBDMA_STOP      0x7000  /* suspend processing */
 120
 121 /* Key values in command field */
 122
 123 #define KEY_MASK        0x0700
 124 #define KEY_STREAM0     0x0000  /* usual data stream */
 125 #define KEY_STREAM1     0x0100  /* control/status stream */
 126 #define KEY_STREAM2     0x0200  /* device-dependent stream */
 127 #define KEY_STREAM3     0x0300  /* device-dependent stream */
 128 #define KEY_STREAM4     0x0400  /* reserved */
 129 #define KEY_REGS        0x0500  /* device register space */
 130 #define KEY_SYSTEM      0x0600  /* system memory-mapped space */
 131 #define KEY_DEVICE      0x0700  /* device memory-mapped space */
 132
 133 /* Interrupt control values in command field */
 134
 135 #define INTR_MASK       0x0030
 136 #define INTR_NEVER      0x0000  /* don't interrupt */
 137 #define INTR_IFSET      0x0010  /* intr if condition bit is 1 */
 138 #define INTR_IFCLR      0x0020  /* intr if condition bit is 0 */
 139 #define INTR_ALWAYS     0x0030  /* always interrupt */
 140
 141 /* Branch control values in command field */
 142
 143 #define BR_MASK         0x000c
 144 #define BR_NEVER        0x0000  /* don't branch */
 145 #define BR_IFSET        0x0004  /* branch if condition bit is 1 */
 146 #define BR_IFCLR        0x0008  /* branch if condition bit is 0 */
 147 #define BR_ALWAYS       0x000c  /* always branch */
 148
 149 /* Wait control values in command field */
 150
 151 #define WAIT_MASK       0x0003
 152 #define WAIT_NEVER      0x0000  /* don't wait */
 153 #define WAIT_IFSET      0x0001  /* wait if condition bit is 1 */
 154 #define WAIT_IFCLR      0x0002  /* wait if condition bit is 0 */
 155 #define WAIT_ALWAYS     0x0003  /* always wait */
 156
 157 typedef struct DBDMA_channel {
 158     int channel;
 159     uint32_t regs[DBDMA_REGS];
 160     qemu_irq irq;
 161     DBDMA_io io;
 162     DBDMA_rw rw;
 163     DBDMA_flush flush;
 164     dbdma_cmd current;
 165     int processing;
 166 } DBDMA_channel;
 167
 168 typedef struct {
 169     MemoryRegion mem;
 170     DBDMA_channel channels[DBDMA_CHANNELS];
 171 } DBDMAState;
 172
 173 #ifdef DEBUG_DBDMA
 174 static void dump_dbdma_cmd(dbdma_cmd *cmd)
 175 {
 176     printf("dbdma_cmd %p\n", cmd);
 177     printf("    req_count 0x%04x\n", le16_to_cpu(cmd->req_count));
 178     printf("    command 0x%04x\n", le16_to_cpu(cmd->command));
 179     printf("    phy_addr 0x%08x\n", le32_to_cpu(cmd->phy_addr));
 180     printf("    cmd_dep 0x%08x\n", le32_to_cpu(cmd->cmd_dep));
 181     printf("    res_count 0x%04x\n", le16_to_cpu(cmd->res_count));
 182     printf("    xfer_status 0x%04x\n", le16_to_cpu(cmd->xfer_status));
 183 }
 184 #else
 185 static void dump_dbdma_cmd(dbdma_cmd *cmd)
 186 {
 187 }
 188 #endif
 189 static void dbdma_cmdptr_load(DBDMA_channel *ch)
 190 {
 191     DBDMA_DPRINTF("dbdma_cmdptr_load 0x%08x\n",
 192                   ch->regs[DBDMA_CMDPTR_LO]);
 193     cpu_physical_memory_read(ch->regs[DBDMA_CMDPTR_LO],
 194                              (uint8_t*)&ch->current, sizeof(dbdma_cmd));
 195 }
 196
 197 static void dbdma_cmdptr_save(DBDMA_channel *ch)
 198 {
 199     DBDMA_DPRINTF("dbdma_cmdptr_save 0x%08x\n",
 200                   ch->regs[DBDMA_CMDPTR_LO]);
 201     DBDMA_DPRINTF("xfer_status 0x%08x res_count 0x%04x\n",
 202                   le16_to_cpu(ch->current.xfer_status),
 203                   le16_to_cpu(ch->current.res_count));
 204     cpu_physical_memory_write(ch->regs[DBDMA_CMDPTR_LO],
 205                               (uint8_t*)&ch->current, sizeof(dbdma_cmd));
 206 }
 207
 208 static void kill_channel(DBDMA_channel *ch)
 209 {
 210     DBDMA_DPRINTF("kill_channel\n");
 211
 212     ch->regs[DBDMA_STATUS] |= DEAD;
 213     ch->regs[DBDMA_STATUS] &= ~ACTIVE;
 214
 215     qemu_irq_raise(ch->irq);
 216 }
 217
 218 static void conditional_interrupt(DBDMA_channel *ch)
 219 {
 220     dbdma_cmd *current = &ch->current;
 221     uint16_t intr;
 222     uint16_t sel_mask, sel_value;
 223     uint32_t status;
 224     int cond;
 225
 226     DBDMA_DPRINTF("conditional_interrupt\n");
 227
 228     intr = le16_to_cpu(current->command) & INTR_MASK;
 229
 230     switch(intr) {
 231     case INTR_NEVER:  /* don't interrupt */
 232         return;
 233     case INTR_ALWAYS: /* always interrupt */
 234         qemu_irq_raise(ch->irq);
 235         return;
 236     }
 237
 238     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
 239
 240     sel_mask = (ch->regs[DBDMA_INTR_SEL] >> 16) & 0x0f;
 241     sel_value = ch->regs[DBDMA_INTR_SEL] & 0x0f;
 242
 243     cond = (status & sel_mask) == (sel_value & sel_mask);
 244
 245     switch(intr) {
 246     case INTR_IFSET:  /* intr if condition bit is 1 */
 247         if (cond)
 248             qemu_irq_raise(ch->irq);
 249         return;
 250     case INTR_IFCLR:  /* intr if condition bit is 0 */
 251         if (!cond)
 252             qemu_irq_raise(ch->irq);
 253         return;
 254     }
 255 }
 256
 257 static int conditional_wait(DBDMA_channel *ch)
 258 {
 259     dbdma_cmd *current = &ch->current;
 260     uint16_t wait;
 261     uint16_t sel_mask, sel_value;
 262     uint32_t status;
 263     int cond;
 264
 265     DBDMA_DPRINTF("conditional_wait\n");
 266
 267     wait = le16_to_cpu(current->command) & WAIT_MASK;
 268
 269     switch(wait) {
 270     case WAIT_NEVER:  /* don't wait */
 271         return 0;
 272     case WAIT_ALWAYS: /* always wait */
 273         return 1;
 274     }
 275
 276     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
 277
 278     sel_mask = (ch->regs[DBDMA_WAIT_SEL] >> 16) & 0x0f;
 279     sel_value = ch->regs[DBDMA_WAIT_SEL] & 0x0f;
 280
 281     cond = (status & sel_mask) == (sel_value & sel_mask);
 282
 283     switch(wait) {
 284     case WAIT_IFSET:  /* wait if condition bit is 1 */
 285         if (cond)
 286             return 1;
 287         return 0;
 288     case WAIT_IFCLR:  /* wait if condition bit is 0 */
 289         if (!cond)
 290             return 1;
 291         return 0;
 292     }
 293     return 0;
 294 }
 295
 296 static void next(DBDMA_channel *ch)
 297 {
 298     uint32_t cp;
 299
 300     ch->regs[DBDMA_STATUS] &= ~BT;
 301
 302     cp = ch->regs[DBDMA_CMDPTR_LO];
 303     ch->regs[DBDMA_CMDPTR_LO] = cp + sizeof(dbdma_cmd);
 304     dbdma_cmdptr_load(ch);
 305 }
 306
 307 static void branch(DBDMA_channel *ch)
 308 {
 309     dbdma_cmd *current = &ch->current;
 310
 311     ch->regs[DBDMA_CMDPTR_LO] = current->cmd_dep;
 312     ch->regs[DBDMA_STATUS] |= BT;
 313     dbdma_cmdptr_load(ch);
 314 }
 315
 316 static void conditional_branch(DBDMA_channel *ch)
 317 {
 318     dbdma_cmd *current = &ch->current;
 319     uint16_t br;
 320     uint16_t sel_mask, sel_value;
 321     uint32_t status;
 322     int cond;
 323
 324     DBDMA_DPRINTF("conditional_branch\n");
 325
 326     /* check if we must branch */
 327
 328     br = le16_to_cpu(current->command) & BR_MASK;
 329
 330     switch(br) {
 331     case BR_NEVER:  /* don't branch */
 332         next(ch);
 333         return;
 334     case BR_ALWAYS: /* always branch */
 335         branch(ch);
 336         return;
 337     }
 338
 339     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
 340
 341     sel_mask = (ch->regs[DBDMA_BRANCH_SEL] >> 16) & 0x0f;
 342     sel_value = ch->regs[DBDMA_BRANCH_SEL] & 0x0f;
 343
 344     cond = (status & sel_mask) == (sel_value & sel_mask);
 345
 346     switch(br) {
 347     case BR_IFSET:  /* branch if condition bit is 1 */
 348         if (cond)
 349             branch(ch);
 350         else
 351             next(ch);
 352         return;
 353     case BR_IFCLR:  /* branch if condition bit is 0 */
 354         if (!cond)
 355             branch(ch);
 356         else
 357             next(ch);
 358         return;
 359     }
 360 }
 361
 362 static QEMUBH *dbdma_bh;
 363 static void channel_run(DBDMA_channel *ch);
 364
 365 static void dbdma_end(DBDMA_io *io)
 366 {
 367     DBDMA_channel *ch = io->channel;
 368     dbdma_cmd *current = &ch->current;
 369
 370     if (conditional_wait(ch))
 371         goto wait;
 372
 373     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
 374     current->res_count = cpu_to_le16(io->len);
 375     dbdma_cmdptr_save(ch);
 376     if (io->is_last)
 377         ch->regs[DBDMA_STATUS] &= ~FLUSH;
 378
 379     conditional_interrupt(ch);
 380     conditional_branch(ch);
 381
 382 wait:
 383     ch->processing = 0;
 384     if ((ch->regs[DBDMA_STATUS] & RUN) &&
 385         (ch->regs[DBDMA_STATUS] & ACTIVE))
 386         channel_run(ch);
 387 }
 388
 389 static void start_output(DBDMA_channel *ch, int key, uint32_t addr,
 390                         uint16_t req_count, int is_last)
 391 {
 392     DBDMA_DPRINTF("start_output\n");
 393
 394     /* KEY_REGS, KEY_DEVICE and KEY_STREAM
 395      * are not implemented in the mac-io chip
 396      */
 397
 398     DBDMA_DPRINTF("addr 0x%x key 0x%x\n", addr, key);
 399     if (!addr || key > KEY_STREAM3) {
 400         kill_channel(ch);
 401         return;
 402     }
 403
 404     ch->io.addr = addr;
 405     ch->io.len = req_count;
 406     ch->io.is_last = is_last;
 407     ch->io.dma_end = dbdma_end;
 408     ch->io.is_dma_out = 1;
 409     ch->processing = 1;
 410     if (ch->rw) {
 411         ch->rw(&ch->io);
 412     }
 413 }
 414
 415 static void start_input(DBDMA_channel *ch, int key, uint32_t addr,
 416                        uint16_t req_count, int is_last)
 417 {
 418     DBDMA_DPRINTF("start_input\n");
 419
 420     /* KEY_REGS, KEY_DEVICE and KEY_STREAM
 421      * are not implemented in the mac-io chip
 422      */
 423
 424     if (!addr || key > KEY_STREAM3) {
 425         kill_channel(ch);
 426         return;
 427     }
 428
 429     ch->io.addr = addr;
 430     ch->io.len = req_count;
 431     ch->io.is_last = is_last;
 432     ch->io.dma_end = dbdma_end;
 433     ch->io.is_dma_out = 0;
 434     ch->processing = 1;
 435     if (ch->rw) {
 436         ch->rw(&ch->io);
 437     }
 438 }
 439
 440 static void load_word(DBDMA_channel *ch, int key, uint32_t addr,
 441                      uint16_t len)
 442 {
 443     dbdma_cmd *current = &ch->current;
 444     uint32_t val;
 445
 446     DBDMA_DPRINTF("load_word\n");
 447
 448     /* only implements KEY_SYSTEM */
 449
 450     if (key != KEY_SYSTEM) {
 451         printf("DBDMA: LOAD_WORD, unimplemented key %x\n", key);
 452         kill_channel(ch);
 453         return;
 454     }
 455
 456     cpu_physical_memory_read(addr, (uint8_t*)&val, len);
 457
 458     if (len == 2)
 459         val = (val << 16) | (current->cmd_dep & 0x0000ffff);
 460     else if (len == 1)
 461         val = (val << 24) | (current->cmd_dep & 0x00ffffff);
 462
 463     current->cmd_dep = val;
 464
 465     if (conditional_wait(ch))
 466         goto wait;
 467
 468     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
 469     dbdma_cmdptr_save(ch);
 470     ch->regs[DBDMA_STATUS] &= ~FLUSH;
 471
 472     conditional_interrupt(ch);
 473     next(ch);
 474
 475 wait:
 476     qemu_bh_schedule(dbdma_bh);
 477 }
 478
 479 static void store_word(DBDMA_channel *ch, int key, uint32_t addr,
 480                       uint16_t len)
 481 {
 482     dbdma_cmd *current = &ch->current;
 483     uint32_t val;
 484
 485     DBDMA_DPRINTF("store_word\n");
 486
 487     /* only implements KEY_SYSTEM */
 488
 489     if (key != KEY_SYSTEM) {
 490         printf("DBDMA: STORE_WORD, unimplemented key %x\n", key);
 491         kill_channel(ch);
 492         return;
 493     }
 494
 495     val = current->cmd_dep;
 496     if (len == 2)
 497         val >>= 16;
 498     else if (len == 1)
 499         val >>= 24;
 500
 501     cpu_physical_memory_write(addr, (uint8_t*)&val, len);
 502
 503     if (conditional_wait(ch))
 504         goto wait;
 505
 506     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
 507     dbdma_cmdptr_save(ch);
 508     ch->regs[DBDMA_STATUS] &= ~FLUSH;
 509
 510     conditional_interrupt(ch);
 511     next(ch);
 512
 513 wait:
 514     qemu_bh_schedule(dbdma_bh);
 515 }
 516
 517 static void nop(DBDMA_channel *ch)
 518 {
 519     dbdma_cmd *current = &ch->current;
 520
 521     if (conditional_wait(ch))
 522         goto wait;
 523
 524     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
 525     dbdma_cmdptr_save(ch);
 526
 527     conditional_interrupt(ch);
 528     conditional_branch(ch);
 529
 530 wait:
 531     qemu_bh_schedule(dbdma_bh);
 532 }
 533
 534 static void stop(DBDMA_channel *ch)
 535 {
 536     ch->regs[DBDMA_STATUS] &= ~(ACTIVE|DEAD|FLUSH);
 537
 538     /* the stop command does not increment command pointer */
 539 }
 540
 541 static void channel_run(DBDMA_channel *ch)
 542 {
 543     dbdma_cmd *current = &ch->current;
 544     uint16_t cmd, key;
 545     uint16_t req_count;
 546     uint32_t phy_addr;
 547
 548     DBDMA_DPRINTF("channel_run\n");
 549     dump_dbdma_cmd(current);
 550
 551     /* clear WAKE flag at command fetch */
 552
 553     ch->regs[DBDMA_STATUS] &= ~WAKE;
 554
 555     cmd = le16_to_cpu(current->command) & COMMAND_MASK;
 556
 557     switch (cmd) {
 558     case DBDMA_NOP:
 559         nop(ch);
 560         return;
 561
 562     case DBDMA_STOP:
 563         stop(ch);
 564         return;
 565     }
 566
 567     key = le16_to_cpu(current->command) & 0x0700;
 568     req_count = le16_to_cpu(current->req_count);
 569     phy_addr = le32_to_cpu(current->phy_addr);
 570
 571     if (key == KEY_STREAM4) {
 572         printf("command %x, invalid key 4\n", cmd);
 573         kill_channel(ch);
 574         return;
 575     }
 576
 577     switch (cmd) {
 578     case OUTPUT_MORE:
 579         start_output(ch, key, phy_addr, req_count, 0);
 580         return;
 581
 582     case OUTPUT_LAST:
 583         start_output(ch, key, phy_addr, req_count, 1);
 584         return;
 585
 586     case INPUT_MORE:
 587         start_input(ch, key, phy_addr, req_count, 0);
 588         return;
 589
 590     case INPUT_LAST:
 591         start_input(ch, key, phy_addr, req_count, 1);
 592         return;
 593     }
 594
 595     if (key < KEY_REGS) {
 596         printf("command %x, invalid key %x\n", cmd, key);
 597         key = KEY_SYSTEM;
 598     }
 599
 600     /* for LOAD_WORD and STORE_WORD, req_count is on 3 bits
 601      * and BRANCH is invalid
 602      */
 603
 604     req_count = req_count & 0x0007;
 605     if (req_count & 0x4) {
 606         req_count = 4;
 607         phy_addr &= ~3;
 608     } else if (req_count & 0x2) {
 609         req_count = 2;
 610         phy_addr &= ~1;
 611     } else
 612         req_count = 1;
 613
 614     switch (cmd) {
 615     case LOAD_WORD:
 616         load_word(ch, key, phy_addr, req_count);
 617         return;
 618
 619     case STORE_WORD:
 620         store_word(ch, key, phy_addr, req_count);
 621         return;
 622     }
 623 }
 624
 625 static void DBDMA_run(DBDMAState *s)
 626 {
 627     int channel;
 628
 629     for (channel = 0; channel < DBDMA_CHANNELS; channel++) {
 630         DBDMA_channel *ch = &s->channels[channel];
 631         uint32_t status = ch->regs[DBDMA_STATUS];
 632         if (!ch->processing && (status & RUN) && (status & ACTIVE)) {
 633             channel_run(ch);
 634         }
 635     }
 636 }
 637
 638 static void DBDMA_run_bh(void *opaque)
 639 {
 640     DBDMAState *s = opaque;
 641
 642     DBDMA_DPRINTF("DBDMA_run_bh\n");
 643
 644     DBDMA_run(s);
 645 }
 646
 647 void DBDMA_register_channel(void *dbdma, int nchan, qemu_irq irq,
 648                             DBDMA_rw rw, DBDMA_flush flush,
 649                             void *opaque)
 650 {
 651     DBDMAState *s = dbdma;
 652     DBDMA_channel *ch = &s->channels[nchan];
 653
 654     DBDMA_DPRINTF("DBDMA_register_channel 0x%x\n", nchan);
 655
 656     ch->irq = irq;
 657     ch->channel = nchan;
 658     ch->rw = rw;
 659     ch->flush = flush;
 660     ch->io.opaque = opaque;
 661     ch->io.channel = ch;
 662 }
 663
 664 void DBDMA_schedule(void)
 665 {
 666     qemu_notify_event();
 667 }
 668
 669 static void
 670 dbdma_control_write(DBDMA_channel *ch)
 671 {
 672     uint16_t mask, value;
 673     uint32_t status;
 674
 675     mask = (ch->regs[DBDMA_CONTROL] >> 16) & 0xffff;
 676     value = ch->regs[DBDMA_CONTROL] & 0xffff;
 677
 678     value &= (RUN | PAUSE | FLUSH | WAKE | DEVSTAT);
 679
 680     status = ch->regs[DBDMA_STATUS];
 681
 682     status = (value & mask) | (status & ~mask);
 683
 684     if (status & WAKE)
 685         status |= ACTIVE;
 686     if (status & RUN) {
 687         status |= ACTIVE;
 688         status &= ~DEAD;
 689     }
 690     if (status & PAUSE)
 691         status &= ~ACTIVE;
 692     if ((ch->regs[DBDMA_STATUS] & RUN) && !(status & RUN)) {
 693         /* RUN is cleared */
 694         status &= ~(ACTIVE|DEAD);
 695     }
 696
 697     DBDMA_DPRINTF("    status 0x%08x\n", status);
 698
 699     ch->regs[DBDMA_STATUS] = status;
 700
 701     if (status & ACTIVE)
 702         qemu_bh_schedule(dbdma_bh);
 703     if ((status & FLUSH) && ch->flush)
 704         ch->flush(&ch->io);
 705 }
 706
 707 static void dbdma_write(void *opaque, target_phys_addr_t addr,
 708                         uint64_t value, unsigned size)
 709 {
 710     int channel = addr >> DBDMA_CHANNEL_SHIFT;
 711     DBDMAState *s = opaque;
 712     DBDMA_channel *ch = &s->channels[channel];
 713     int reg = (addr - (channel << DBDMA_CHANNEL_SHIFT)) >> 2;
 714
 715     DBDMA_DPRINTF("writel 0x" TARGET_FMT_plx " <= 0x%08x\n", addr, value);
 716     DBDMA_DPRINTF("channel 0x%x reg 0x%x\n",
 717                   (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
 718
 719     /* cmdptr cannot be modified if channel is RUN or ACTIVE */
 720
 721     if (reg == DBDMA_CMDPTR_LO &&
 722         (ch->regs[DBDMA_STATUS] & (RUN | ACTIVE)))
 723         return;
 724
 725     ch->regs[reg] = value;
 726
 727     switch(reg) {
 728     case DBDMA_CONTROL:
 729         dbdma_control_write(ch);
 730         break;
 731     case DBDMA_CMDPTR_LO:
 732         /* 16-byte aligned */
 733         ch->regs[DBDMA_CMDPTR_LO] &= ~0xf;
 734         dbdma_cmdptr_load(ch);
 735         break;
 736     case DBDMA_STATUS:
 737     case DBDMA_INTR_SEL:
 738     case DBDMA_BRANCH_SEL:
 739     case DBDMA_WAIT_SEL:
 740         /* nothing to do */
 741         break;
 742     case DBDMA_XFER_MODE:
 743     case DBDMA_CMDPTR_HI:
 744     case DBDMA_DATA2PTR_HI:
 745     case DBDMA_DATA2PTR_LO:
 746     case DBDMA_ADDRESS_HI:
 747     case DBDMA_BRANCH_ADDR_HI:
 748     case DBDMA_RES1:
 749     case DBDMA_RES2:
 750     case DBDMA_RES3:
 751     case DBDMA_RES4:
 752         /* unused */
 753         break;
 754     }
 755 }
 756
 757 static uint64_t dbdma_read(void *opaque, target_phys_addr_t addr,
 758                            unsigned size)
 759 {
 760     uint32_t value;
 761     int channel = addr >> DBDMA_CHANNEL_SHIFT;
 762     DBDMAState *s = opaque;
 763     DBDMA_channel *ch = &s->channels[channel];
 764     int reg = (addr - (channel << DBDMA_CHANNEL_SHIFT)) >> 2;
 765
 766     value = ch->regs[reg];
 767
 768     DBDMA_DPRINTF("readl 0x" TARGET_FMT_plx " => 0x%08x\n", addr, value);
 769     DBDMA_DPRINTF("channel 0x%x reg 0x%x\n",
 770                   (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
 771
 772     switch(reg) {
 773     case DBDMA_CONTROL:
 774         value = 0;
 775         break;
 776     case DBDMA_STATUS:
 777     case DBDMA_CMDPTR_LO:
 778     case DBDMA_INTR_SEL:
 779     case DBDMA_BRANCH_SEL:
 780     case DBDMA_WAIT_SEL:
 781         /* nothing to do */
 782         break;
 783     case DBDMA_XFER_MODE:
 784     case DBDMA_CMDPTR_HI:
 785     case DBDMA_DATA2PTR_HI:
 786     case DBDMA_DATA2PTR_LO:
 787     case DBDMA_ADDRESS_HI:
 788     case DBDMA_BRANCH_ADDR_HI:
 789         /* unused */
 790         value = 0;
 791         break;
 792     case DBDMA_RES1:
 793     case DBDMA_RES2:
 794     case DBDMA_RES3:
 795     case DBDMA_RES4:
 796         /* reserved */
 797         break;
 798     }
 799
 800     return value;
 801 }
 802
 803 static const MemoryRegionOps dbdma_ops = {
 804     .read = dbdma_read,
 805     .write = dbdma_write,
 806     .endianness = DEVICE_LITTLE_ENDIAN,
 807     .valid = {
 808         .min_access_size = 4,
 809         .max_access_size = 4,
 810     },
 811 };
 812
 813 static const VMStateDescription vmstate_dbdma_channel = {
 814     .name = "dbdma_channel",
 815     .version_id = 0,
 816     .minimum_version_id = 0,
 817     .minimum_version_id_old = 0,
 818     .fields      = (VMStateField[]) {
 819         VMSTATE_UINT32_ARRAY(regs, struct DBDMA_channel, DBDMA_REGS),
 820         VMSTATE_END_OF_LIST()
 821     }
 822 };
 823
 824 static const VMStateDescription vmstate_dbdma = {
 825     .name = "dbdma",
 826     .version_id = 2,
 827     .minimum_version_id = 2,
 828     .minimum_version_id_old = 2,
 829     .fields      = (VMStateField[]) {
 830         VMSTATE_STRUCT_ARRAY(channels, DBDMAState, DBDMA_CHANNELS, 1,
 831                              vmstate_dbdma_channel, DBDMA_channel),
 832         VMSTATE_END_OF_LIST()
 833     }
 834 };
 835
 836 static void dbdma_reset(void *opaque)
 837 {
 838     DBDMAState *s = opaque;
 839     int i;
 840
 841     for (i = 0; i < DBDMA_CHANNELS; i++)
 842         memset(s->channels[i].regs, 0, DBDMA_SIZE);
 843 }
 844
 845 void* DBDMA_init (MemoryRegion **dbdma_mem)
 846 {
 847     DBDMAState *s;
 848
 849     s = qemu_mallocz(sizeof(DBDMAState));
 850
 851     memory_region_init_io(&s->mem, &dbdma_ops, s, "dbdma", 0x1000);
 852     *dbdma_mem = &s->mem;
 853     vmstate_register(NULL, -1, &vmstate_dbdma, s);
 854     qemu_register_reset(dbdma_reset, s);
 855
 856     dbdma_bh = qemu_bh_new(DBDMA_run_bh, s);
 857
 858     return s;
 859 }