xref: /openbmc/qemu/hw/misc/macio/mac_dbdma.c (revision 62aa1d88)
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 "qemu/osdep.h"
40 #include "hw/hw.h"
41 #include "hw/isa/isa.h"
42 #include "hw/ppc/mac_dbdma.h"
43 #include "qemu/main-loop.h"
44 #include "qemu/log.h"
45 #include "sysemu/dma.h"
46 
47 /* debug DBDMA */
48 #define DEBUG_DBDMA 0
49 #define DEBUG_DBDMA_CHANMASK ((1ull << DBDMA_CHANNELS) - 1)
50 
51 #define DBDMA_DPRINTF(fmt, ...) do { \
52     if (DEBUG_DBDMA) { \
53         printf("DBDMA: " fmt , ## __VA_ARGS__); \
54     } \
55 } while (0)
56 
57 #define DBDMA_DPRINTFCH(ch, fmt, ...) do { \
58     if (DEBUG_DBDMA) { \
59         if ((1ul << (ch)->channel) & DEBUG_DBDMA_CHANMASK) { \
60             printf("DBDMA[%02x]: " fmt , (ch)->channel, ## __VA_ARGS__); \
61         } \
62     } \
63 } while (0)
64 
65 /*
66  */
67 
68 static DBDMAState *dbdma_from_ch(DBDMA_channel *ch)
69 {
70     return container_of(ch, DBDMAState, channels[ch->channel]);
71 }
72 
73 #if DEBUG_DBDMA
74 static void dump_dbdma_cmd(DBDMA_channel *ch, dbdma_cmd *cmd)
75 {
76     DBDMA_DPRINTFCH(ch, "dbdma_cmd %p\n", cmd);
77     DBDMA_DPRINTFCH(ch, "    req_count 0x%04x\n", le16_to_cpu(cmd->req_count));
78     DBDMA_DPRINTFCH(ch, "    command 0x%04x\n", le16_to_cpu(cmd->command));
79     DBDMA_DPRINTFCH(ch, "    phy_addr 0x%08x\n", le32_to_cpu(cmd->phy_addr));
80     DBDMA_DPRINTFCH(ch, "    cmd_dep 0x%08x\n", le32_to_cpu(cmd->cmd_dep));
81     DBDMA_DPRINTFCH(ch, "    res_count 0x%04x\n", le16_to_cpu(cmd->res_count));
82     DBDMA_DPRINTFCH(ch, "    xfer_status 0x%04x\n",
83                     le16_to_cpu(cmd->xfer_status));
84 }
85 #else
86 static void dump_dbdma_cmd(DBDMA_channel *ch, dbdma_cmd *cmd)
87 {
88 }
89 #endif
90 static void dbdma_cmdptr_load(DBDMA_channel *ch)
91 {
92     DBDMA_DPRINTFCH(ch, "dbdma_cmdptr_load 0x%08x\n",
93                     ch->regs[DBDMA_CMDPTR_LO]);
94     dma_memory_read(&address_space_memory, ch->regs[DBDMA_CMDPTR_LO],
95                     &ch->current, sizeof(dbdma_cmd));
96 }
97 
98 static void dbdma_cmdptr_save(DBDMA_channel *ch)
99 {
100     DBDMA_DPRINTFCH(ch, "-> update 0x%08x stat=0x%08x, res=0x%04x\n",
101                     ch->regs[DBDMA_CMDPTR_LO],
102                     le16_to_cpu(ch->current.xfer_status),
103                     le16_to_cpu(ch->current.res_count));
104     dma_memory_write(&address_space_memory, ch->regs[DBDMA_CMDPTR_LO],
105                      &ch->current, sizeof(dbdma_cmd));
106 }
107 
108 static void kill_channel(DBDMA_channel *ch)
109 {
110     DBDMA_DPRINTFCH(ch, "kill_channel\n");
111 
112     ch->regs[DBDMA_STATUS] |= DEAD;
113     ch->regs[DBDMA_STATUS] &= ~ACTIVE;
114 
115     qemu_irq_raise(ch->irq);
116 }
117 
118 static void conditional_interrupt(DBDMA_channel *ch)
119 {
120     dbdma_cmd *current = &ch->current;
121     uint16_t intr;
122     uint16_t sel_mask, sel_value;
123     uint32_t status;
124     int cond;
125 
126     DBDMA_DPRINTFCH(ch, "%s\n", __func__);
127 
128     intr = le16_to_cpu(current->command) & INTR_MASK;
129 
130     switch(intr) {
131     case INTR_NEVER:  /* don't interrupt */
132         return;
133     case INTR_ALWAYS: /* always interrupt */
134         qemu_irq_raise(ch->irq);
135         DBDMA_DPRINTFCH(ch, "%s: raise\n", __func__);
136         return;
137     }
138 
139     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
140 
141     sel_mask = (ch->regs[DBDMA_INTR_SEL] >> 16) & 0x0f;
142     sel_value = ch->regs[DBDMA_INTR_SEL] & 0x0f;
143 
144     cond = (status & sel_mask) == (sel_value & sel_mask);
145 
146     switch(intr) {
147     case INTR_IFSET:  /* intr if condition bit is 1 */
148         if (cond) {
149             qemu_irq_raise(ch->irq);
150             DBDMA_DPRINTFCH(ch, "%s: raise\n", __func__);
151         }
152         return;
153     case INTR_IFCLR:  /* intr if condition bit is 0 */
154         if (!cond) {
155             qemu_irq_raise(ch->irq);
156             DBDMA_DPRINTFCH(ch, "%s: raise\n", __func__);
157         }
158         return;
159     }
160 }
161 
162 static int conditional_wait(DBDMA_channel *ch)
163 {
164     dbdma_cmd *current = &ch->current;
165     uint16_t wait;
166     uint16_t sel_mask, sel_value;
167     uint32_t status;
168     int cond;
169     int res = 0;
170 
171     wait = le16_to_cpu(current->command) & WAIT_MASK;
172     switch(wait) {
173     case WAIT_NEVER:  /* don't wait */
174         return 0;
175     case WAIT_ALWAYS: /* always wait */
176         DBDMA_DPRINTFCH(ch, "  [WAIT_ALWAYS]\n");
177         return 1;
178     }
179 
180     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
181 
182     sel_mask = (ch->regs[DBDMA_WAIT_SEL] >> 16) & 0x0f;
183     sel_value = ch->regs[DBDMA_WAIT_SEL] & 0x0f;
184 
185     cond = (status & sel_mask) == (sel_value & sel_mask);
186 
187     switch(wait) {
188     case WAIT_IFSET:  /* wait if condition bit is 1 */
189         if (cond) {
190             res = 1;
191         }
192         DBDMA_DPRINTFCH(ch, "  [WAIT_IFSET=%d]\n", res);
193         break;
194     case WAIT_IFCLR:  /* wait if condition bit is 0 */
195         if (!cond) {
196             res = 1;
197         }
198         DBDMA_DPRINTFCH(ch, "  [WAIT_IFCLR=%d]\n", res);
199         break;
200     }
201     return res;
202 }
203 
204 static void next(DBDMA_channel *ch)
205 {
206     uint32_t cp;
207 
208     ch->regs[DBDMA_STATUS] &= ~BT;
209 
210     cp = ch->regs[DBDMA_CMDPTR_LO];
211     ch->regs[DBDMA_CMDPTR_LO] = cp + sizeof(dbdma_cmd);
212     dbdma_cmdptr_load(ch);
213 }
214 
215 static void branch(DBDMA_channel *ch)
216 {
217     dbdma_cmd *current = &ch->current;
218 
219     ch->regs[DBDMA_CMDPTR_LO] = le32_to_cpu(current->cmd_dep);
220     ch->regs[DBDMA_STATUS] |= BT;
221     dbdma_cmdptr_load(ch);
222 }
223 
224 static void conditional_branch(DBDMA_channel *ch)
225 {
226     dbdma_cmd *current = &ch->current;
227     uint16_t br;
228     uint16_t sel_mask, sel_value;
229     uint32_t status;
230     int cond;
231 
232     /* check if we must branch */
233 
234     br = le16_to_cpu(current->command) & BR_MASK;
235 
236     switch(br) {
237     case BR_NEVER:  /* don't branch */
238         next(ch);
239         return;
240     case BR_ALWAYS: /* always branch */
241         DBDMA_DPRINTFCH(ch, "  [BR_ALWAYS]\n");
242         branch(ch);
243         return;
244     }
245 
246     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
247 
248     sel_mask = (ch->regs[DBDMA_BRANCH_SEL] >> 16) & 0x0f;
249     sel_value = ch->regs[DBDMA_BRANCH_SEL] & 0x0f;
250 
251     cond = (status & sel_mask) == (sel_value & sel_mask);
252 
253     switch(br) {
254     case BR_IFSET:  /* branch if condition bit is 1 */
255         if (cond) {
256             DBDMA_DPRINTFCH(ch, "  [BR_IFSET = 1]\n");
257             branch(ch);
258         } else {
259             DBDMA_DPRINTFCH(ch, "  [BR_IFSET = 0]\n");
260             next(ch);
261         }
262         return;
263     case BR_IFCLR:  /* branch if condition bit is 0 */
264         if (!cond) {
265             DBDMA_DPRINTFCH(ch, "  [BR_IFCLR = 1]\n");
266             branch(ch);
267         } else {
268             DBDMA_DPRINTFCH(ch, "  [BR_IFCLR = 0]\n");
269             next(ch);
270         }
271         return;
272     }
273 }
274 
275 static void channel_run(DBDMA_channel *ch);
276 
277 static void dbdma_end(DBDMA_io *io)
278 {
279     DBDMA_channel *ch = io->channel;
280     dbdma_cmd *current = &ch->current;
281 
282     DBDMA_DPRINTFCH(ch, "%s\n", __func__);
283 
284     if (conditional_wait(ch))
285         goto wait;
286 
287     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
288     current->res_count = cpu_to_le16(io->len);
289     dbdma_cmdptr_save(ch);
290     if (io->is_last)
291         ch->regs[DBDMA_STATUS] &= ~FLUSH;
292 
293     conditional_interrupt(ch);
294     conditional_branch(ch);
295 
296 wait:
297     /* Indicate that we're ready for a new DMA round */
298     ch->io.processing = false;
299 
300     if ((ch->regs[DBDMA_STATUS] & RUN) &&
301         (ch->regs[DBDMA_STATUS] & ACTIVE))
302         channel_run(ch);
303 }
304 
305 static void start_output(DBDMA_channel *ch, int key, uint32_t addr,
306                         uint16_t req_count, int is_last)
307 {
308     DBDMA_DPRINTFCH(ch, "start_output\n");
309 
310     /* KEY_REGS, KEY_DEVICE and KEY_STREAM
311      * are not implemented in the mac-io chip
312      */
313 
314     DBDMA_DPRINTFCH(ch, "addr 0x%x key 0x%x\n", addr, key);
315     if (!addr || key > KEY_STREAM3) {
316         kill_channel(ch);
317         return;
318     }
319 
320     ch->io.addr = addr;
321     ch->io.len = req_count;
322     ch->io.is_last = is_last;
323     ch->io.dma_end = dbdma_end;
324     ch->io.is_dma_out = 1;
325     ch->io.processing = true;
326     if (ch->rw) {
327         ch->rw(&ch->io);
328     }
329 }
330 
331 static void start_input(DBDMA_channel *ch, int key, uint32_t addr,
332                        uint16_t req_count, int is_last)
333 {
334     DBDMA_DPRINTFCH(ch, "start_input\n");
335 
336     /* KEY_REGS, KEY_DEVICE and KEY_STREAM
337      * are not implemented in the mac-io chip
338      */
339 
340     DBDMA_DPRINTFCH(ch, "addr 0x%x key 0x%x\n", addr, key);
341     if (!addr || key > KEY_STREAM3) {
342         kill_channel(ch);
343         return;
344     }
345 
346     ch->io.addr = addr;
347     ch->io.len = req_count;
348     ch->io.is_last = is_last;
349     ch->io.dma_end = dbdma_end;
350     ch->io.is_dma_out = 0;
351     ch->io.processing = true;
352     if (ch->rw) {
353         ch->rw(&ch->io);
354     }
355 }
356 
357 static void load_word(DBDMA_channel *ch, int key, uint32_t addr,
358                      uint16_t len)
359 {
360     dbdma_cmd *current = &ch->current;
361 
362     DBDMA_DPRINTFCH(ch, "load_word %d bytes, addr=%08x\n", len, addr);
363 
364     /* only implements KEY_SYSTEM */
365 
366     if (key != KEY_SYSTEM) {
367         printf("DBDMA: LOAD_WORD, unimplemented key %x\n", key);
368         kill_channel(ch);
369         return;
370     }
371 
372     dma_memory_read(&address_space_memory, addr, &current->cmd_dep, len);
373 
374     if (conditional_wait(ch))
375         goto wait;
376 
377     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
378     dbdma_cmdptr_save(ch);
379     ch->regs[DBDMA_STATUS] &= ~FLUSH;
380 
381     conditional_interrupt(ch);
382     next(ch);
383 
384 wait:
385     DBDMA_kick(dbdma_from_ch(ch));
386 }
387 
388 static void store_word(DBDMA_channel *ch, int key, uint32_t addr,
389                       uint16_t len)
390 {
391     dbdma_cmd *current = &ch->current;
392 
393     DBDMA_DPRINTFCH(ch, "store_word %d bytes, addr=%08x pa=%x\n",
394                     len, addr, le32_to_cpu(current->cmd_dep));
395 
396     /* only implements KEY_SYSTEM */
397 
398     if (key != KEY_SYSTEM) {
399         printf("DBDMA: STORE_WORD, unimplemented key %x\n", key);
400         kill_channel(ch);
401         return;
402     }
403 
404     dma_memory_write(&address_space_memory, addr, &current->cmd_dep, len);
405 
406     if (conditional_wait(ch))
407         goto wait;
408 
409     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
410     dbdma_cmdptr_save(ch);
411     ch->regs[DBDMA_STATUS] &= ~FLUSH;
412 
413     conditional_interrupt(ch);
414     next(ch);
415 
416 wait:
417     DBDMA_kick(dbdma_from_ch(ch));
418 }
419 
420 static void nop(DBDMA_channel *ch)
421 {
422     dbdma_cmd *current = &ch->current;
423 
424     if (conditional_wait(ch))
425         goto wait;
426 
427     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
428     dbdma_cmdptr_save(ch);
429 
430     conditional_interrupt(ch);
431     conditional_branch(ch);
432 
433 wait:
434     DBDMA_kick(dbdma_from_ch(ch));
435 }
436 
437 static void stop(DBDMA_channel *ch)
438 {
439     ch->regs[DBDMA_STATUS] &= ~(ACTIVE);
440 
441     /* the stop command does not increment command pointer */
442 }
443 
444 static void channel_run(DBDMA_channel *ch)
445 {
446     dbdma_cmd *current = &ch->current;
447     uint16_t cmd, key;
448     uint16_t req_count;
449     uint32_t phy_addr;
450 
451     DBDMA_DPRINTFCH(ch, "channel_run\n");
452     dump_dbdma_cmd(ch, current);
453 
454     /* clear WAKE flag at command fetch */
455 
456     ch->regs[DBDMA_STATUS] &= ~WAKE;
457 
458     cmd = le16_to_cpu(current->command) & COMMAND_MASK;
459 
460     switch (cmd) {
461     case DBDMA_NOP:
462         nop(ch);
463         return;
464 
465     case DBDMA_STOP:
466         stop(ch);
467         return;
468     }
469 
470     key = le16_to_cpu(current->command) & 0x0700;
471     req_count = le16_to_cpu(current->req_count);
472     phy_addr = le32_to_cpu(current->phy_addr);
473 
474     if (key == KEY_STREAM4) {
475         printf("command %x, invalid key 4\n", cmd);
476         kill_channel(ch);
477         return;
478     }
479 
480     switch (cmd) {
481     case OUTPUT_MORE:
482         DBDMA_DPRINTFCH(ch, "* OUTPUT_MORE *\n");
483         start_output(ch, key, phy_addr, req_count, 0);
484         return;
485 
486     case OUTPUT_LAST:
487         DBDMA_DPRINTFCH(ch, "* OUTPUT_LAST *\n");
488         start_output(ch, key, phy_addr, req_count, 1);
489         return;
490 
491     case INPUT_MORE:
492         DBDMA_DPRINTFCH(ch, "* INPUT_MORE *\n");
493         start_input(ch, key, phy_addr, req_count, 0);
494         return;
495 
496     case INPUT_LAST:
497         DBDMA_DPRINTFCH(ch, "* INPUT_LAST *\n");
498         start_input(ch, key, phy_addr, req_count, 1);
499         return;
500     }
501 
502     if (key < KEY_REGS) {
503         printf("command %x, invalid key %x\n", cmd, key);
504         key = KEY_SYSTEM;
505     }
506 
507     /* for LOAD_WORD and STORE_WORD, req_count is on 3 bits
508      * and BRANCH is invalid
509      */
510 
511     req_count = req_count & 0x0007;
512     if (req_count & 0x4) {
513         req_count = 4;
514         phy_addr &= ~3;
515     } else if (req_count & 0x2) {
516         req_count = 2;
517         phy_addr &= ~1;
518     } else
519         req_count = 1;
520 
521     switch (cmd) {
522     case LOAD_WORD:
523         DBDMA_DPRINTFCH(ch, "* LOAD_WORD *\n");
524         load_word(ch, key, phy_addr, req_count);
525         return;
526 
527     case STORE_WORD:
528         DBDMA_DPRINTFCH(ch, "* STORE_WORD *\n");
529         store_word(ch, key, phy_addr, req_count);
530         return;
531     }
532 }
533 
534 static void DBDMA_run(DBDMAState *s)
535 {
536     int channel;
537 
538     for (channel = 0; channel < DBDMA_CHANNELS; channel++) {
539         DBDMA_channel *ch = &s->channels[channel];
540         uint32_t status = ch->regs[DBDMA_STATUS];
541         if (!ch->io.processing && (status & RUN) && (status & ACTIVE)) {
542             channel_run(ch);
543         }
544     }
545 }
546 
547 static void DBDMA_run_bh(void *opaque)
548 {
549     DBDMAState *s = opaque;
550 
551     DBDMA_DPRINTF("-> DBDMA_run_bh\n");
552     DBDMA_run(s);
553     DBDMA_DPRINTF("<- DBDMA_run_bh\n");
554 }
555 
556 void DBDMA_kick(DBDMAState *dbdma)
557 {
558     qemu_bh_schedule(dbdma->bh);
559 }
560 
561 void DBDMA_register_channel(void *dbdma, int nchan, qemu_irq irq,
562                             DBDMA_rw rw, DBDMA_flush flush,
563                             void *opaque)
564 {
565     DBDMAState *s = dbdma;
566     DBDMA_channel *ch = &s->channels[nchan];
567 
568     DBDMA_DPRINTFCH(ch, "DBDMA_register_channel 0x%x\n", nchan);
569 
570     assert(rw);
571     assert(flush);
572 
573     ch->irq = irq;
574     ch->rw = rw;
575     ch->flush = flush;
576     ch->io.opaque = opaque;
577 }
578 
579 static void dbdma_control_write(DBDMA_channel *ch)
580 {
581     uint16_t mask, value;
582     uint32_t status;
583     bool do_flush = false;
584 
585     mask = (ch->regs[DBDMA_CONTROL] >> 16) & 0xffff;
586     value = ch->regs[DBDMA_CONTROL] & 0xffff;
587 
588     /* This is the status register which we'll update
589      * appropriately and store back
590      */
591     status = ch->regs[DBDMA_STATUS];
592 
593     /* RUN and PAUSE are bits under SW control only
594      * FLUSH and WAKE are set by SW and cleared by HW
595      * DEAD, ACTIVE and BT are only under HW control
596      *
597      * We handle ACTIVE separately at the end of the
598      * logic to ensure all cases are covered.
599      */
600 
601     /* Setting RUN will tentatively activate the channel
602      */
603     if ((mask & RUN) && (value & RUN)) {
604         status |= RUN;
605         DBDMA_DPRINTFCH(ch, " Setting RUN !\n");
606     }
607 
608     /* Clearing RUN 1->0 will stop the channel */
609     if ((mask & RUN) && !(value & RUN)) {
610         /* This has the side effect of clearing the DEAD bit */
611         status &= ~(DEAD | RUN);
612         DBDMA_DPRINTFCH(ch, " Clearing RUN !\n");
613     }
614 
615     /* Setting WAKE wakes up an idle channel if it's running
616      *
617      * Note: The doc doesn't say so but assume that only works
618      * on a channel whose RUN bit is set.
619      *
620      * We set WAKE in status, it's not terribly useful as it will
621      * be cleared on the next command fetch but it seems to mimmic
622      * the HW behaviour and is useful for the way we handle
623      * ACTIVE further down.
624      */
625     if ((mask & WAKE) && (value & WAKE) && (status & RUN)) {
626         status |= WAKE;
627         DBDMA_DPRINTFCH(ch, " Setting WAKE !\n");
628     }
629 
630     /* PAUSE being set will deactivate (or prevent activation)
631      * of the channel. We just copy it over for now, ACTIVE will
632      * be re-evaluated later.
633      */
634     if (mask & PAUSE) {
635         status = (status & ~PAUSE) | (value & PAUSE);
636         DBDMA_DPRINTFCH(ch, " %sing PAUSE !\n",
637                         (value & PAUSE) ? "sett" : "clear");
638     }
639 
640     /* FLUSH is its own thing */
641     if ((mask & FLUSH) && (value & FLUSH))  {
642         DBDMA_DPRINTFCH(ch, " Setting FLUSH !\n");
643         /* We set flush directly in the status register, we do *NOT*
644          * set it in "status" so that it gets naturally cleared when
645          * we update the status register further down. That way it
646          * will be set only during the HW flush operation so it is
647          * visible to any completions happening during that time.
648          */
649         ch->regs[DBDMA_STATUS] |= FLUSH;
650         do_flush = true;
651     }
652 
653     /* If either RUN or PAUSE is clear, so should ACTIVE be,
654      * otherwise, ACTIVE will be set if we modified RUN, PAUSE or
655      * set WAKE. That means that PAUSE was just cleared, RUN was
656      * just set or WAKE was just set.
657      */
658     if ((status & PAUSE) || !(status & RUN)) {
659         status &= ~ACTIVE;
660         DBDMA_DPRINTFCH(ch, "  -> ACTIVE down !\n");
661 
662         /* We stopped processing, we want the underlying HW command
663          * to complete *before* we clear the ACTIVE bit. Otherwise
664          * we can get into a situation where the command status will
665          * have RUN or ACTIVE not set which is going to confuse the
666          * MacOS driver.
667          */
668         do_flush = true;
669     } else if (mask & (RUN | PAUSE)) {
670         status |= ACTIVE;
671         DBDMA_DPRINTFCH(ch, " -> ACTIVE up !\n");
672     } else if ((mask & WAKE) && (value & WAKE)) {
673         status |= ACTIVE;
674         DBDMA_DPRINTFCH(ch, " -> ACTIVE up !\n");
675     }
676 
677     DBDMA_DPRINTFCH(ch, " new status=0x%08x\n", status);
678 
679     /* If we need to flush the underlying HW, do it now, this happens
680      * both on FLUSH commands and when stopping the channel for safety.
681      */
682     if (do_flush && ch->flush) {
683         ch->flush(&ch->io);
684     }
685 
686     /* Finally update the status register image */
687     ch->regs[DBDMA_STATUS] = status;
688 
689     /* If active, make sure the BH gets to run */
690     if (status & ACTIVE) {
691         DBDMA_kick(dbdma_from_ch(ch));
692     }
693 }
694 
695 static void dbdma_write(void *opaque, hwaddr addr,
696                         uint64_t value, unsigned size)
697 {
698     int channel = addr >> DBDMA_CHANNEL_SHIFT;
699     DBDMAState *s = opaque;
700     DBDMA_channel *ch = &s->channels[channel];
701     int reg = (addr - (channel << DBDMA_CHANNEL_SHIFT)) >> 2;
702 
703     DBDMA_DPRINTFCH(ch, "writel 0x" TARGET_FMT_plx " <= 0x%08"PRIx64"\n",
704                     addr, value);
705     DBDMA_DPRINTFCH(ch, "channel 0x%x reg 0x%x\n",
706                     (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
707 
708     /* cmdptr cannot be modified if channel is ACTIVE */
709 
710     if (reg == DBDMA_CMDPTR_LO && (ch->regs[DBDMA_STATUS] & ACTIVE)) {
711         return;
712     }
713 
714     ch->regs[reg] = value;
715 
716     switch(reg) {
717     case DBDMA_CONTROL:
718         dbdma_control_write(ch);
719         break;
720     case DBDMA_CMDPTR_LO:
721         /* 16-byte aligned */
722         ch->regs[DBDMA_CMDPTR_LO] &= ~0xf;
723         dbdma_cmdptr_load(ch);
724         break;
725     case DBDMA_STATUS:
726     case DBDMA_INTR_SEL:
727     case DBDMA_BRANCH_SEL:
728     case DBDMA_WAIT_SEL:
729         /* nothing to do */
730         break;
731     case DBDMA_XFER_MODE:
732     case DBDMA_CMDPTR_HI:
733     case DBDMA_DATA2PTR_HI:
734     case DBDMA_DATA2PTR_LO:
735     case DBDMA_ADDRESS_HI:
736     case DBDMA_BRANCH_ADDR_HI:
737     case DBDMA_RES1:
738     case DBDMA_RES2:
739     case DBDMA_RES3:
740     case DBDMA_RES4:
741         /* unused */
742         break;
743     }
744 }
745 
746 static uint64_t dbdma_read(void *opaque, hwaddr addr,
747                            unsigned size)
748 {
749     uint32_t value;
750     int channel = addr >> DBDMA_CHANNEL_SHIFT;
751     DBDMAState *s = opaque;
752     DBDMA_channel *ch = &s->channels[channel];
753     int reg = (addr - (channel << DBDMA_CHANNEL_SHIFT)) >> 2;
754 
755     value = ch->regs[reg];
756 
757     switch(reg) {
758     case DBDMA_CONTROL:
759         value = ch->regs[DBDMA_STATUS];
760         break;
761     case DBDMA_STATUS:
762     case DBDMA_CMDPTR_LO:
763     case DBDMA_INTR_SEL:
764     case DBDMA_BRANCH_SEL:
765     case DBDMA_WAIT_SEL:
766         /* nothing to do */
767         break;
768     case DBDMA_XFER_MODE:
769     case DBDMA_CMDPTR_HI:
770     case DBDMA_DATA2PTR_HI:
771     case DBDMA_DATA2PTR_LO:
772     case DBDMA_ADDRESS_HI:
773     case DBDMA_BRANCH_ADDR_HI:
774         /* unused */
775         value = 0;
776         break;
777     case DBDMA_RES1:
778     case DBDMA_RES2:
779     case DBDMA_RES3:
780     case DBDMA_RES4:
781         /* reserved */
782         break;
783     }
784 
785     DBDMA_DPRINTFCH(ch, "readl 0x" TARGET_FMT_plx " => 0x%08x\n", addr, value);
786     DBDMA_DPRINTFCH(ch, "channel 0x%x reg 0x%x\n",
787                     (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
788 
789     return value;
790 }
791 
792 static const MemoryRegionOps dbdma_ops = {
793     .read = dbdma_read,
794     .write = dbdma_write,
795     .endianness = DEVICE_LITTLE_ENDIAN,
796     .valid = {
797         .min_access_size = 4,
798         .max_access_size = 4,
799     },
800 };
801 
802 static const VMStateDescription vmstate_dbdma_io = {
803     .name = "dbdma_io",
804     .version_id = 0,
805     .minimum_version_id = 0,
806     .fields = (VMStateField[]) {
807         VMSTATE_UINT64(addr, struct DBDMA_io),
808         VMSTATE_INT32(len, struct DBDMA_io),
809         VMSTATE_INT32(is_last, struct DBDMA_io),
810         VMSTATE_INT32(is_dma_out, struct DBDMA_io),
811         VMSTATE_BOOL(processing, struct DBDMA_io),
812         VMSTATE_END_OF_LIST()
813     }
814 };
815 
816 static const VMStateDescription vmstate_dbdma_cmd = {
817     .name = "dbdma_cmd",
818     .version_id = 0,
819     .minimum_version_id = 0,
820     .fields = (VMStateField[]) {
821         VMSTATE_UINT16(req_count, dbdma_cmd),
822         VMSTATE_UINT16(command, dbdma_cmd),
823         VMSTATE_UINT32(phy_addr, dbdma_cmd),
824         VMSTATE_UINT32(cmd_dep, dbdma_cmd),
825         VMSTATE_UINT16(res_count, dbdma_cmd),
826         VMSTATE_UINT16(xfer_status, dbdma_cmd),
827         VMSTATE_END_OF_LIST()
828     }
829 };
830 
831 static const VMStateDescription vmstate_dbdma_channel = {
832     .name = "dbdma_channel",
833     .version_id = 1,
834     .minimum_version_id = 1,
835     .fields = (VMStateField[]) {
836         VMSTATE_UINT32_ARRAY(regs, struct DBDMA_channel, DBDMA_REGS),
837         VMSTATE_STRUCT(io, struct DBDMA_channel, 0, vmstate_dbdma_io, DBDMA_io),
838         VMSTATE_STRUCT(current, struct DBDMA_channel, 0, vmstate_dbdma_cmd,
839                        dbdma_cmd),
840         VMSTATE_END_OF_LIST()
841     }
842 };
843 
844 static const VMStateDescription vmstate_dbdma = {
845     .name = "dbdma",
846     .version_id = 3,
847     .minimum_version_id = 3,
848     .fields = (VMStateField[]) {
849         VMSTATE_STRUCT_ARRAY(channels, DBDMAState, DBDMA_CHANNELS, 1,
850                              vmstate_dbdma_channel, DBDMA_channel),
851         VMSTATE_END_OF_LIST()
852     }
853 };
854 
855 static void mac_dbdma_reset(DeviceState *d)
856 {
857     DBDMAState *s = MAC_DBDMA(d);
858     int i;
859 
860     for (i = 0; i < DBDMA_CHANNELS; i++) {
861         memset(s->channels[i].regs, 0, DBDMA_SIZE);
862     }
863 }
864 
865 static void dbdma_unassigned_rw(DBDMA_io *io)
866 {
867     DBDMA_channel *ch = io->channel;
868     dbdma_cmd *current = &ch->current;
869     uint16_t cmd;
870     qemu_log_mask(LOG_GUEST_ERROR, "%s: use of unassigned channel %d\n",
871                   __func__, ch->channel);
872     ch->io.processing = false;
873 
874     cmd = le16_to_cpu(current->command) & COMMAND_MASK;
875     if (cmd == OUTPUT_MORE || cmd == OUTPUT_LAST ||
876         cmd == INPUT_MORE || cmd == INPUT_LAST) {
877         current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
878         current->res_count = cpu_to_le16(io->len);
879         dbdma_cmdptr_save(ch);
880     }
881 }
882 
883 static void dbdma_unassigned_flush(DBDMA_io *io)
884 {
885     DBDMA_channel *ch = io->channel;
886     qemu_log_mask(LOG_GUEST_ERROR, "%s: use of unassigned channel %d\n",
887                   __func__, ch->channel);
888 }
889 
890 static void mac_dbdma_init(Object *obj)
891 {
892     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
893     DBDMAState *s = MAC_DBDMA(obj);
894     int i;
895 
896     for (i = 0; i < DBDMA_CHANNELS; i++) {
897         DBDMA_channel *ch = &s->channels[i];
898 
899         ch->rw = dbdma_unassigned_rw;
900         ch->flush = dbdma_unassigned_flush;
901         ch->channel = i;
902         ch->io.channel = ch;
903     }
904 
905     memory_region_init_io(&s->mem, obj, &dbdma_ops, s, "dbdma", 0x1000);
906     sysbus_init_mmio(sbd, &s->mem);
907 }
908 
909 static void mac_dbdma_realize(DeviceState *dev, Error **errp)
910 {
911     DBDMAState *s = MAC_DBDMA(dev);
912 
913     s->bh = qemu_bh_new(DBDMA_run_bh, s);
914 }
915 
916 static void mac_dbdma_class_init(ObjectClass *oc, void *data)
917 {
918     DeviceClass *dc = DEVICE_CLASS(oc);
919 
920     dc->realize = mac_dbdma_realize;
921     dc->reset = mac_dbdma_reset;
922     dc->vmsd = &vmstate_dbdma;
923 }
924 
925 static const TypeInfo mac_dbdma_type_info = {
926     .name = TYPE_MAC_DBDMA,
927     .parent = TYPE_SYS_BUS_DEVICE,
928     .instance_size = sizeof(DBDMAState),
929     .instance_init = mac_dbdma_init,
930     .class_init = mac_dbdma_class_init
931 };
932 
933 static void mac_dbdma_register_types(void)
934 {
935     type_register_static(&mac_dbdma_type_info);
936 }
937 
938 type_init(mac_dbdma_register_types)
939