xref: /openbmc/qemu/hw/misc/macio/mac_dbdma.c (revision e05ae1d9)
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/ppc/mac_dbdma.h"
42 #include "qemu/main-loop.h"
43 #include "qemu/log.h"
44 #include "sysemu/dma.h"
45 
46 /* debug DBDMA */
47 #define DEBUG_DBDMA 0
48 #define DEBUG_DBDMA_CHANMASK ((1ull << DBDMA_CHANNELS) - 1)
49 
50 #define DBDMA_DPRINTF(fmt, ...) do { \
51     if (DEBUG_DBDMA) { \
52         printf("DBDMA: " fmt , ## __VA_ARGS__); \
53     } \
54 } while (0)
55 
56 #define DBDMA_DPRINTFCH(ch, fmt, ...) do { \
57     if (DEBUG_DBDMA) { \
58         if ((1ul << (ch)->channel) & DEBUG_DBDMA_CHANMASK) { \
59             printf("DBDMA[%02x]: " fmt , (ch)->channel, ## __VA_ARGS__); \
60         } \
61     } \
62 } while (0)
63 
64 /*
65  */
66 
67 static DBDMAState *dbdma_from_ch(DBDMA_channel *ch)
68 {
69     return container_of(ch, DBDMAState, channels[ch->channel]);
70 }
71 
72 #if DEBUG_DBDMA
73 static void dump_dbdma_cmd(DBDMA_channel *ch, dbdma_cmd *cmd)
74 {
75     DBDMA_DPRINTFCH(ch, "dbdma_cmd %p\n", cmd);
76     DBDMA_DPRINTFCH(ch, "    req_count 0x%04x\n", le16_to_cpu(cmd->req_count));
77     DBDMA_DPRINTFCH(ch, "    command 0x%04x\n", le16_to_cpu(cmd->command));
78     DBDMA_DPRINTFCH(ch, "    phy_addr 0x%08x\n", le32_to_cpu(cmd->phy_addr));
79     DBDMA_DPRINTFCH(ch, "    cmd_dep 0x%08x\n", le32_to_cpu(cmd->cmd_dep));
80     DBDMA_DPRINTFCH(ch, "    res_count 0x%04x\n", le16_to_cpu(cmd->res_count));
81     DBDMA_DPRINTFCH(ch, "    xfer_status 0x%04x\n",
82                     le16_to_cpu(cmd->xfer_status));
83 }
84 #else
85 static void dump_dbdma_cmd(DBDMA_channel *ch, dbdma_cmd *cmd)
86 {
87 }
88 #endif
89 static void dbdma_cmdptr_load(DBDMA_channel *ch)
90 {
91     DBDMA_DPRINTFCH(ch, "dbdma_cmdptr_load 0x%08x\n",
92                     ch->regs[DBDMA_CMDPTR_LO]);
93     dma_memory_read(&address_space_memory, ch->regs[DBDMA_CMDPTR_LO],
94                     &ch->current, sizeof(dbdma_cmd));
95 }
96 
97 static void dbdma_cmdptr_save(DBDMA_channel *ch)
98 {
99     DBDMA_DPRINTFCH(ch, "-> update 0x%08x stat=0x%08x, res=0x%04x\n",
100                     ch->regs[DBDMA_CMDPTR_LO],
101                     le16_to_cpu(ch->current.xfer_status),
102                     le16_to_cpu(ch->current.res_count));
103     dma_memory_write(&address_space_memory, ch->regs[DBDMA_CMDPTR_LO],
104                      &ch->current, sizeof(dbdma_cmd));
105 }
106 
107 static void kill_channel(DBDMA_channel *ch)
108 {
109     DBDMA_DPRINTFCH(ch, "kill_channel\n");
110 
111     ch->regs[DBDMA_STATUS] |= DEAD;
112     ch->regs[DBDMA_STATUS] &= ~ACTIVE;
113 
114     qemu_irq_raise(ch->irq);
115 }
116 
117 static void conditional_interrupt(DBDMA_channel *ch)
118 {
119     dbdma_cmd *current = &ch->current;
120     uint16_t intr;
121     uint16_t sel_mask, sel_value;
122     uint32_t status;
123     int cond;
124 
125     DBDMA_DPRINTFCH(ch, "%s\n", __func__);
126 
127     intr = le16_to_cpu(current->command) & INTR_MASK;
128 
129     switch(intr) {
130     case INTR_NEVER:  /* don't interrupt */
131         return;
132     case INTR_ALWAYS: /* always interrupt */
133         qemu_irq_raise(ch->irq);
134         DBDMA_DPRINTFCH(ch, "%s: raise\n", __func__);
135         return;
136     }
137 
138     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
139 
140     sel_mask = (ch->regs[DBDMA_INTR_SEL] >> 16) & 0x0f;
141     sel_value = ch->regs[DBDMA_INTR_SEL] & 0x0f;
142 
143     cond = (status & sel_mask) == (sel_value & sel_mask);
144 
145     switch(intr) {
146     case INTR_IFSET:  /* intr if condition bit is 1 */
147         if (cond) {
148             qemu_irq_raise(ch->irq);
149             DBDMA_DPRINTFCH(ch, "%s: raise\n", __func__);
150         }
151         return;
152     case INTR_IFCLR:  /* intr if condition bit is 0 */
153         if (!cond) {
154             qemu_irq_raise(ch->irq);
155             DBDMA_DPRINTFCH(ch, "%s: raise\n", __func__);
156         }
157         return;
158     }
159 }
160 
161 static int conditional_wait(DBDMA_channel *ch)
162 {
163     dbdma_cmd *current = &ch->current;
164     uint16_t wait;
165     uint16_t sel_mask, sel_value;
166     uint32_t status;
167     int cond;
168     int res = 0;
169 
170     wait = le16_to_cpu(current->command) & WAIT_MASK;
171     switch(wait) {
172     case WAIT_NEVER:  /* don't wait */
173         return 0;
174     case WAIT_ALWAYS: /* always wait */
175         DBDMA_DPRINTFCH(ch, "  [WAIT_ALWAYS]\n");
176         return 1;
177     }
178 
179     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
180 
181     sel_mask = (ch->regs[DBDMA_WAIT_SEL] >> 16) & 0x0f;
182     sel_value = ch->regs[DBDMA_WAIT_SEL] & 0x0f;
183 
184     cond = (status & sel_mask) == (sel_value & sel_mask);
185 
186     switch(wait) {
187     case WAIT_IFSET:  /* wait if condition bit is 1 */
188         if (cond) {
189             res = 1;
190         }
191         DBDMA_DPRINTFCH(ch, "  [WAIT_IFSET=%d]\n", res);
192         break;
193     case WAIT_IFCLR:  /* wait if condition bit is 0 */
194         if (!cond) {
195             res = 1;
196         }
197         DBDMA_DPRINTFCH(ch, "  [WAIT_IFCLR=%d]\n", res);
198         break;
199     }
200     return res;
201 }
202 
203 static void next(DBDMA_channel *ch)
204 {
205     uint32_t cp;
206 
207     ch->regs[DBDMA_STATUS] &= ~BT;
208 
209     cp = ch->regs[DBDMA_CMDPTR_LO];
210     ch->regs[DBDMA_CMDPTR_LO] = cp + sizeof(dbdma_cmd);
211     dbdma_cmdptr_load(ch);
212 }
213 
214 static void branch(DBDMA_channel *ch)
215 {
216     dbdma_cmd *current = &ch->current;
217 
218     ch->regs[DBDMA_CMDPTR_LO] = le32_to_cpu(current->cmd_dep);
219     ch->regs[DBDMA_STATUS] |= BT;
220     dbdma_cmdptr_load(ch);
221 }
222 
223 static void conditional_branch(DBDMA_channel *ch)
224 {
225     dbdma_cmd *current = &ch->current;
226     uint16_t br;
227     uint16_t sel_mask, sel_value;
228     uint32_t status;
229     int cond;
230 
231     /* check if we must branch */
232 
233     br = le16_to_cpu(current->command) & BR_MASK;
234 
235     switch(br) {
236     case BR_NEVER:  /* don't branch */
237         next(ch);
238         return;
239     case BR_ALWAYS: /* always branch */
240         DBDMA_DPRINTFCH(ch, "  [BR_ALWAYS]\n");
241         branch(ch);
242         return;
243     }
244 
245     status = ch->regs[DBDMA_STATUS] & DEVSTAT;
246 
247     sel_mask = (ch->regs[DBDMA_BRANCH_SEL] >> 16) & 0x0f;
248     sel_value = ch->regs[DBDMA_BRANCH_SEL] & 0x0f;
249 
250     cond = (status & sel_mask) == (sel_value & sel_mask);
251 
252     switch(br) {
253     case BR_IFSET:  /* branch if condition bit is 1 */
254         if (cond) {
255             DBDMA_DPRINTFCH(ch, "  [BR_IFSET = 1]\n");
256             branch(ch);
257         } else {
258             DBDMA_DPRINTFCH(ch, "  [BR_IFSET = 0]\n");
259             next(ch);
260         }
261         return;
262     case BR_IFCLR:  /* branch if condition bit is 0 */
263         if (!cond) {
264             DBDMA_DPRINTFCH(ch, "  [BR_IFCLR = 1]\n");
265             branch(ch);
266         } else {
267             DBDMA_DPRINTFCH(ch, "  [BR_IFCLR = 0]\n");
268             next(ch);
269         }
270         return;
271     }
272 }
273 
274 static void channel_run(DBDMA_channel *ch);
275 
276 static void dbdma_end(DBDMA_io *io)
277 {
278     DBDMA_channel *ch = io->channel;
279     dbdma_cmd *current = &ch->current;
280 
281     DBDMA_DPRINTFCH(ch, "%s\n", __func__);
282 
283     if (conditional_wait(ch))
284         goto wait;
285 
286     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
287     current->res_count = cpu_to_le16(io->len);
288     dbdma_cmdptr_save(ch);
289     if (io->is_last)
290         ch->regs[DBDMA_STATUS] &= ~FLUSH;
291 
292     conditional_interrupt(ch);
293     conditional_branch(ch);
294 
295 wait:
296     /* Indicate that we're ready for a new DMA round */
297     ch->io.processing = false;
298 
299     if ((ch->regs[DBDMA_STATUS] & RUN) &&
300         (ch->regs[DBDMA_STATUS] & ACTIVE))
301         channel_run(ch);
302 }
303 
304 static void start_output(DBDMA_channel *ch, int key, uint32_t addr,
305                         uint16_t req_count, int is_last)
306 {
307     DBDMA_DPRINTFCH(ch, "start_output\n");
308 
309     /* KEY_REGS, KEY_DEVICE and KEY_STREAM
310      * are not implemented in the mac-io chip
311      */
312 
313     DBDMA_DPRINTFCH(ch, "addr 0x%x key 0x%x\n", addr, key);
314     if (!addr || key > KEY_STREAM3) {
315         kill_channel(ch);
316         return;
317     }
318 
319     ch->io.addr = addr;
320     ch->io.len = req_count;
321     ch->io.is_last = is_last;
322     ch->io.dma_end = dbdma_end;
323     ch->io.is_dma_out = 1;
324     ch->io.processing = true;
325     if (ch->rw) {
326         ch->rw(&ch->io);
327     }
328 }
329 
330 static void start_input(DBDMA_channel *ch, int key, uint32_t addr,
331                        uint16_t req_count, int is_last)
332 {
333     DBDMA_DPRINTFCH(ch, "start_input\n");
334 
335     /* KEY_REGS, KEY_DEVICE and KEY_STREAM
336      * are not implemented in the mac-io chip
337      */
338 
339     DBDMA_DPRINTFCH(ch, "addr 0x%x key 0x%x\n", addr, key);
340     if (!addr || key > KEY_STREAM3) {
341         kill_channel(ch);
342         return;
343     }
344 
345     ch->io.addr = addr;
346     ch->io.len = req_count;
347     ch->io.is_last = is_last;
348     ch->io.dma_end = dbdma_end;
349     ch->io.is_dma_out = 0;
350     ch->io.processing = true;
351     if (ch->rw) {
352         ch->rw(&ch->io);
353     }
354 }
355 
356 static void load_word(DBDMA_channel *ch, int key, uint32_t addr,
357                      uint16_t len)
358 {
359     dbdma_cmd *current = &ch->current;
360 
361     DBDMA_DPRINTFCH(ch, "load_word %d bytes, addr=%08x\n", len, addr);
362 
363     /* only implements KEY_SYSTEM */
364 
365     if (key != KEY_SYSTEM) {
366         printf("DBDMA: LOAD_WORD, unimplemented key %x\n", key);
367         kill_channel(ch);
368         return;
369     }
370 
371     dma_memory_read(&address_space_memory, addr, &current->cmd_dep, len);
372 
373     if (conditional_wait(ch))
374         goto wait;
375 
376     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
377     dbdma_cmdptr_save(ch);
378     ch->regs[DBDMA_STATUS] &= ~FLUSH;
379 
380     conditional_interrupt(ch);
381     next(ch);
382 
383 wait:
384     DBDMA_kick(dbdma_from_ch(ch));
385 }
386 
387 static void store_word(DBDMA_channel *ch, int key, uint32_t addr,
388                       uint16_t len)
389 {
390     dbdma_cmd *current = &ch->current;
391 
392     DBDMA_DPRINTFCH(ch, "store_word %d bytes, addr=%08x pa=%x\n",
393                     len, addr, le32_to_cpu(current->cmd_dep));
394 
395     /* only implements KEY_SYSTEM */
396 
397     if (key != KEY_SYSTEM) {
398         printf("DBDMA: STORE_WORD, unimplemented key %x\n", key);
399         kill_channel(ch);
400         return;
401     }
402 
403     dma_memory_write(&address_space_memory, addr, &current->cmd_dep, len);
404 
405     if (conditional_wait(ch))
406         goto wait;
407 
408     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
409     dbdma_cmdptr_save(ch);
410     ch->regs[DBDMA_STATUS] &= ~FLUSH;
411 
412     conditional_interrupt(ch);
413     next(ch);
414 
415 wait:
416     DBDMA_kick(dbdma_from_ch(ch));
417 }
418 
419 static void nop(DBDMA_channel *ch)
420 {
421     dbdma_cmd *current = &ch->current;
422 
423     if (conditional_wait(ch))
424         goto wait;
425 
426     current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
427     dbdma_cmdptr_save(ch);
428 
429     conditional_interrupt(ch);
430     conditional_branch(ch);
431 
432 wait:
433     DBDMA_kick(dbdma_from_ch(ch));
434 }
435 
436 static void stop(DBDMA_channel *ch)
437 {
438     ch->regs[DBDMA_STATUS] &= ~(ACTIVE);
439 
440     /* the stop command does not increment command pointer */
441 }
442 
443 static void channel_run(DBDMA_channel *ch)
444 {
445     dbdma_cmd *current = &ch->current;
446     uint16_t cmd, key;
447     uint16_t req_count;
448     uint32_t phy_addr;
449 
450     DBDMA_DPRINTFCH(ch, "channel_run\n");
451     dump_dbdma_cmd(ch, current);
452 
453     /* clear WAKE flag at command fetch */
454 
455     ch->regs[DBDMA_STATUS] &= ~WAKE;
456 
457     cmd = le16_to_cpu(current->command) & COMMAND_MASK;
458 
459     switch (cmd) {
460     case DBDMA_NOP:
461         nop(ch);
462         return;
463 
464     case DBDMA_STOP:
465         stop(ch);
466         return;
467     }
468 
469     key = le16_to_cpu(current->command) & 0x0700;
470     req_count = le16_to_cpu(current->req_count);
471     phy_addr = le32_to_cpu(current->phy_addr);
472 
473     if (key == KEY_STREAM4) {
474         printf("command %x, invalid key 4\n", cmd);
475         kill_channel(ch);
476         return;
477     }
478 
479     switch (cmd) {
480     case OUTPUT_MORE:
481         DBDMA_DPRINTFCH(ch, "* OUTPUT_MORE *\n");
482         start_output(ch, key, phy_addr, req_count, 0);
483         return;
484 
485     case OUTPUT_LAST:
486         DBDMA_DPRINTFCH(ch, "* OUTPUT_LAST *\n");
487         start_output(ch, key, phy_addr, req_count, 1);
488         return;
489 
490     case INPUT_MORE:
491         DBDMA_DPRINTFCH(ch, "* INPUT_MORE *\n");
492         start_input(ch, key, phy_addr, req_count, 0);
493         return;
494 
495     case INPUT_LAST:
496         DBDMA_DPRINTFCH(ch, "* INPUT_LAST *\n");
497         start_input(ch, key, phy_addr, req_count, 1);
498         return;
499     }
500 
501     if (key < KEY_REGS) {
502         printf("command %x, invalid key %x\n", cmd, key);
503         key = KEY_SYSTEM;
504     }
505 
506     /* for LOAD_WORD and STORE_WORD, req_count is on 3 bits
507      * and BRANCH is invalid
508      */
509 
510     req_count = req_count & 0x0007;
511     if (req_count & 0x4) {
512         req_count = 4;
513         phy_addr &= ~3;
514     } else if (req_count & 0x2) {
515         req_count = 2;
516         phy_addr &= ~1;
517     } else
518         req_count = 1;
519 
520     switch (cmd) {
521     case LOAD_WORD:
522         DBDMA_DPRINTFCH(ch, "* LOAD_WORD *\n");
523         load_word(ch, key, phy_addr, req_count);
524         return;
525 
526     case STORE_WORD:
527         DBDMA_DPRINTFCH(ch, "* STORE_WORD *\n");
528         store_word(ch, key, phy_addr, req_count);
529         return;
530     }
531 }
532 
533 static void DBDMA_run(DBDMAState *s)
534 {
535     int channel;
536 
537     for (channel = 0; channel < DBDMA_CHANNELS; channel++) {
538         DBDMA_channel *ch = &s->channels[channel];
539         uint32_t status = ch->regs[DBDMA_STATUS];
540         if (!ch->io.processing && (status & RUN) && (status & ACTIVE)) {
541             channel_run(ch);
542         }
543     }
544 }
545 
546 static void DBDMA_run_bh(void *opaque)
547 {
548     DBDMAState *s = opaque;
549 
550     DBDMA_DPRINTF("-> DBDMA_run_bh\n");
551     DBDMA_run(s);
552     DBDMA_DPRINTF("<- DBDMA_run_bh\n");
553 }
554 
555 void DBDMA_kick(DBDMAState *dbdma)
556 {
557     qemu_bh_schedule(dbdma->bh);
558 }
559 
560 void DBDMA_register_channel(void *dbdma, int nchan, qemu_irq irq,
561                             DBDMA_rw rw, DBDMA_flush flush,
562                             void *opaque)
563 {
564     DBDMAState *s = dbdma;
565     DBDMA_channel *ch = &s->channels[nchan];
566 
567     DBDMA_DPRINTFCH(ch, "DBDMA_register_channel 0x%x\n", nchan);
568 
569     assert(rw);
570     assert(flush);
571 
572     ch->irq = irq;
573     ch->rw = rw;
574     ch->flush = flush;
575     ch->io.opaque = opaque;
576 }
577 
578 static void dbdma_control_write(DBDMA_channel *ch)
579 {
580     uint16_t mask, value;
581     uint32_t status;
582     bool do_flush = false;
583 
584     mask = (ch->regs[DBDMA_CONTROL] >> 16) & 0xffff;
585     value = ch->regs[DBDMA_CONTROL] & 0xffff;
586 
587     /* This is the status register which we'll update
588      * appropriately and store back
589      */
590     status = ch->regs[DBDMA_STATUS];
591 
592     /* RUN and PAUSE are bits under SW control only
593      * FLUSH and WAKE are set by SW and cleared by HW
594      * DEAD, ACTIVE and BT are only under HW control
595      *
596      * We handle ACTIVE separately at the end of the
597      * logic to ensure all cases are covered.
598      */
599 
600     /* Setting RUN will tentatively activate the channel
601      */
602     if ((mask & RUN) && (value & RUN)) {
603         status |= RUN;
604         DBDMA_DPRINTFCH(ch, " Setting RUN !\n");
605     }
606 
607     /* Clearing RUN 1->0 will stop the channel */
608     if ((mask & RUN) && !(value & RUN)) {
609         /* This has the side effect of clearing the DEAD bit */
610         status &= ~(DEAD | RUN);
611         DBDMA_DPRINTFCH(ch, " Clearing RUN !\n");
612     }
613 
614     /* Setting WAKE wakes up an idle channel if it's running
615      *
616      * Note: The doc doesn't say so but assume that only works
617      * on a channel whose RUN bit is set.
618      *
619      * We set WAKE in status, it's not terribly useful as it will
620      * be cleared on the next command fetch but it seems to mimmic
621      * the HW behaviour and is useful for the way we handle
622      * ACTIVE further down.
623      */
624     if ((mask & WAKE) && (value & WAKE) && (status & RUN)) {
625         status |= WAKE;
626         DBDMA_DPRINTFCH(ch, " Setting WAKE !\n");
627     }
628 
629     /* PAUSE being set will deactivate (or prevent activation)
630      * of the channel. We just copy it over for now, ACTIVE will
631      * be re-evaluated later.
632      */
633     if (mask & PAUSE) {
634         status = (status & ~PAUSE) | (value & PAUSE);
635         DBDMA_DPRINTFCH(ch, " %sing PAUSE !\n",
636                         (value & PAUSE) ? "sett" : "clear");
637     }
638 
639     /* FLUSH is its own thing */
640     if ((mask & FLUSH) && (value & FLUSH))  {
641         DBDMA_DPRINTFCH(ch, " Setting FLUSH !\n");
642         /* We set flush directly in the status register, we do *NOT*
643          * set it in "status" so that it gets naturally cleared when
644          * we update the status register further down. That way it
645          * will be set only during the HW flush operation so it is
646          * visible to any completions happening during that time.
647          */
648         ch->regs[DBDMA_STATUS] |= FLUSH;
649         do_flush = true;
650     }
651 
652     /* If either RUN or PAUSE is clear, so should ACTIVE be,
653      * otherwise, ACTIVE will be set if we modified RUN, PAUSE or
654      * set WAKE. That means that PAUSE was just cleared, RUN was
655      * just set or WAKE was just set.
656      */
657     if ((status & PAUSE) || !(status & RUN)) {
658         status &= ~ACTIVE;
659         DBDMA_DPRINTFCH(ch, "  -> ACTIVE down !\n");
660 
661         /* We stopped processing, we want the underlying HW command
662          * to complete *before* we clear the ACTIVE bit. Otherwise
663          * we can get into a situation where the command status will
664          * have RUN or ACTIVE not set which is going to confuse the
665          * MacOS driver.
666          */
667         do_flush = true;
668     } else if (mask & (RUN | PAUSE)) {
669         status |= ACTIVE;
670         DBDMA_DPRINTFCH(ch, " -> ACTIVE up !\n");
671     } else if ((mask & WAKE) && (value & WAKE)) {
672         status |= ACTIVE;
673         DBDMA_DPRINTFCH(ch, " -> ACTIVE up !\n");
674     }
675 
676     DBDMA_DPRINTFCH(ch, " new status=0x%08x\n", status);
677 
678     /* If we need to flush the underlying HW, do it now, this happens
679      * both on FLUSH commands and when stopping the channel for safety.
680      */
681     if (do_flush && ch->flush) {
682         ch->flush(&ch->io);
683     }
684 
685     /* Finally update the status register image */
686     ch->regs[DBDMA_STATUS] = status;
687 
688     /* If active, make sure the BH gets to run */
689     if (status & ACTIVE) {
690         DBDMA_kick(dbdma_from_ch(ch));
691     }
692 }
693 
694 static void dbdma_write(void *opaque, hwaddr addr,
695                         uint64_t value, unsigned size)
696 {
697     int channel = addr >> DBDMA_CHANNEL_SHIFT;
698     DBDMAState *s = opaque;
699     DBDMA_channel *ch = &s->channels[channel];
700     int reg = (addr - (channel << DBDMA_CHANNEL_SHIFT)) >> 2;
701 
702     DBDMA_DPRINTFCH(ch, "writel 0x" TARGET_FMT_plx " <= 0x%08"PRIx64"\n",
703                     addr, value);
704     DBDMA_DPRINTFCH(ch, "channel 0x%x reg 0x%x\n",
705                     (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
706 
707     /* cmdptr cannot be modified if channel is ACTIVE */
708 
709     if (reg == DBDMA_CMDPTR_LO && (ch->regs[DBDMA_STATUS] & ACTIVE)) {
710         return;
711     }
712 
713     ch->regs[reg] = value;
714 
715     switch(reg) {
716     case DBDMA_CONTROL:
717         dbdma_control_write(ch);
718         break;
719     case DBDMA_CMDPTR_LO:
720         /* 16-byte aligned */
721         ch->regs[DBDMA_CMDPTR_LO] &= ~0xf;
722         dbdma_cmdptr_load(ch);
723         break;
724     case DBDMA_STATUS:
725     case DBDMA_INTR_SEL:
726     case DBDMA_BRANCH_SEL:
727     case DBDMA_WAIT_SEL:
728         /* nothing to do */
729         break;
730     case DBDMA_XFER_MODE:
731     case DBDMA_CMDPTR_HI:
732     case DBDMA_DATA2PTR_HI:
733     case DBDMA_DATA2PTR_LO:
734     case DBDMA_ADDRESS_HI:
735     case DBDMA_BRANCH_ADDR_HI:
736     case DBDMA_RES1:
737     case DBDMA_RES2:
738     case DBDMA_RES3:
739     case DBDMA_RES4:
740         /* unused */
741         break;
742     }
743 }
744 
745 static uint64_t dbdma_read(void *opaque, hwaddr addr,
746                            unsigned size)
747 {
748     uint32_t value;
749     int channel = addr >> DBDMA_CHANNEL_SHIFT;
750     DBDMAState *s = opaque;
751     DBDMA_channel *ch = &s->channels[channel];
752     int reg = (addr - (channel << DBDMA_CHANNEL_SHIFT)) >> 2;
753 
754     value = ch->regs[reg];
755 
756     switch(reg) {
757     case DBDMA_CONTROL:
758         value = ch->regs[DBDMA_STATUS];
759         break;
760     case DBDMA_STATUS:
761     case DBDMA_CMDPTR_LO:
762     case DBDMA_INTR_SEL:
763     case DBDMA_BRANCH_SEL:
764     case DBDMA_WAIT_SEL:
765         /* nothing to do */
766         break;
767     case DBDMA_XFER_MODE:
768     case DBDMA_CMDPTR_HI:
769     case DBDMA_DATA2PTR_HI:
770     case DBDMA_DATA2PTR_LO:
771     case DBDMA_ADDRESS_HI:
772     case DBDMA_BRANCH_ADDR_HI:
773         /* unused */
774         value = 0;
775         break;
776     case DBDMA_RES1:
777     case DBDMA_RES2:
778     case DBDMA_RES3:
779     case DBDMA_RES4:
780         /* reserved */
781         break;
782     }
783 
784     DBDMA_DPRINTFCH(ch, "readl 0x" TARGET_FMT_plx " => 0x%08x\n", addr, value);
785     DBDMA_DPRINTFCH(ch, "channel 0x%x reg 0x%x\n",
786                     (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
787 
788     return value;
789 }
790 
791 static const MemoryRegionOps dbdma_ops = {
792     .read = dbdma_read,
793     .write = dbdma_write,
794     .endianness = DEVICE_LITTLE_ENDIAN,
795     .valid = {
796         .min_access_size = 4,
797         .max_access_size = 4,
798     },
799 };
800 
801 static const VMStateDescription vmstate_dbdma_io = {
802     .name = "dbdma_io",
803     .version_id = 0,
804     .minimum_version_id = 0,
805     .fields = (VMStateField[]) {
806         VMSTATE_UINT64(addr, struct DBDMA_io),
807         VMSTATE_INT32(len, struct DBDMA_io),
808         VMSTATE_INT32(is_last, struct DBDMA_io),
809         VMSTATE_INT32(is_dma_out, struct DBDMA_io),
810         VMSTATE_BOOL(processing, struct DBDMA_io),
811         VMSTATE_END_OF_LIST()
812     }
813 };
814 
815 static const VMStateDescription vmstate_dbdma_cmd = {
816     .name = "dbdma_cmd",
817     .version_id = 0,
818     .minimum_version_id = 0,
819     .fields = (VMStateField[]) {
820         VMSTATE_UINT16(req_count, dbdma_cmd),
821         VMSTATE_UINT16(command, dbdma_cmd),
822         VMSTATE_UINT32(phy_addr, dbdma_cmd),
823         VMSTATE_UINT32(cmd_dep, dbdma_cmd),
824         VMSTATE_UINT16(res_count, dbdma_cmd),
825         VMSTATE_UINT16(xfer_status, dbdma_cmd),
826         VMSTATE_END_OF_LIST()
827     }
828 };
829 
830 static const VMStateDescription vmstate_dbdma_channel = {
831     .name = "dbdma_channel",
832     .version_id = 1,
833     .minimum_version_id = 1,
834     .fields = (VMStateField[]) {
835         VMSTATE_UINT32_ARRAY(regs, struct DBDMA_channel, DBDMA_REGS),
836         VMSTATE_STRUCT(io, struct DBDMA_channel, 0, vmstate_dbdma_io, DBDMA_io),
837         VMSTATE_STRUCT(current, struct DBDMA_channel, 0, vmstate_dbdma_cmd,
838                        dbdma_cmd),
839         VMSTATE_END_OF_LIST()
840     }
841 };
842 
843 static const VMStateDescription vmstate_dbdma = {
844     .name = "dbdma",
845     .version_id = 3,
846     .minimum_version_id = 3,
847     .fields = (VMStateField[]) {
848         VMSTATE_STRUCT_ARRAY(channels, DBDMAState, DBDMA_CHANNELS, 1,
849                              vmstate_dbdma_channel, DBDMA_channel),
850         VMSTATE_END_OF_LIST()
851     }
852 };
853 
854 static void mac_dbdma_reset(DeviceState *d)
855 {
856     DBDMAState *s = MAC_DBDMA(d);
857     int i;
858 
859     for (i = 0; i < DBDMA_CHANNELS; i++) {
860         memset(s->channels[i].regs, 0, DBDMA_SIZE);
861     }
862 }
863 
864 static void dbdma_unassigned_rw(DBDMA_io *io)
865 {
866     DBDMA_channel *ch = io->channel;
867     dbdma_cmd *current = &ch->current;
868     uint16_t cmd;
869     qemu_log_mask(LOG_GUEST_ERROR, "%s: use of unassigned channel %d\n",
870                   __func__, ch->channel);
871     ch->io.processing = false;
872 
873     cmd = le16_to_cpu(current->command) & COMMAND_MASK;
874     if (cmd == OUTPUT_MORE || cmd == OUTPUT_LAST ||
875         cmd == INPUT_MORE || cmd == INPUT_LAST) {
876         current->xfer_status = cpu_to_le16(ch->regs[DBDMA_STATUS]);
877         current->res_count = cpu_to_le16(io->len);
878         dbdma_cmdptr_save(ch);
879     }
880 }
881 
882 static void dbdma_unassigned_flush(DBDMA_io *io)
883 {
884     DBDMA_channel *ch = io->channel;
885     qemu_log_mask(LOG_GUEST_ERROR, "%s: use of unassigned channel %d\n",
886                   __func__, ch->channel);
887 }
888 
889 static void mac_dbdma_init(Object *obj)
890 {
891     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
892     DBDMAState *s = MAC_DBDMA(obj);
893     int i;
894 
895     for (i = 0; i < DBDMA_CHANNELS; i++) {
896         DBDMA_channel *ch = &s->channels[i];
897 
898         ch->rw = dbdma_unassigned_rw;
899         ch->flush = dbdma_unassigned_flush;
900         ch->channel = i;
901         ch->io.channel = ch;
902     }
903 
904     memory_region_init_io(&s->mem, obj, &dbdma_ops, s, "dbdma", 0x1000);
905     sysbus_init_mmio(sbd, &s->mem);
906 }
907 
908 static void mac_dbdma_realize(DeviceState *dev, Error **errp)
909 {
910     DBDMAState *s = MAC_DBDMA(dev);
911 
912     s->bh = qemu_bh_new(DBDMA_run_bh, s);
913 }
914 
915 static void mac_dbdma_class_init(ObjectClass *oc, void *data)
916 {
917     DeviceClass *dc = DEVICE_CLASS(oc);
918 
919     dc->realize = mac_dbdma_realize;
920     dc->reset = mac_dbdma_reset;
921     dc->vmsd = &vmstate_dbdma;
922 }
923 
924 static const TypeInfo mac_dbdma_type_info = {
925     .name = TYPE_MAC_DBDMA,
926     .parent = TYPE_SYS_BUS_DEVICE,
927     .instance_size = sizeof(DBDMAState),
928     .instance_init = mac_dbdma_init,
929     .class_init = mac_dbdma_class_init
930 };
931 
932 static void mac_dbdma_register_types(void)
933 {
934     type_register_static(&mac_dbdma_type_info);
935 }
936 
937 type_init(mac_dbdma_register_types)
938