xref: /qemu/hw/scsi/esp.c (revision f366622366807ce7e11cd74e501620840d8a3cda)
1 /*
2  * QEMU ESP/NCR53C9x emulation
3  *
4  * Copyright (c) 2005-2006 Fabrice Bellard
5  * Copyright (c) 2012 Herve Poussineau
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "hw/sysbus.h"
28 #include "migration/vmstate.h"
29 #include "hw/irq.h"
30 #include "hw/scsi/esp.h"
31 #include "trace.h"
32 #include "qemu/log.h"
33 #include "qemu/module.h"
34 
35 /*
36  * On Sparc32, this is the ESP (NCR53C90) part of chip STP2000 (Master I/O),
37  * also produced as NCR89C100. See
38  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
39  * and
40  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR53C9X.txt
41  *
42  * On Macintosh Quadra it is a NCR53C96.
43  */
44 
45 static void esp_raise_irq(ESPState *s)
46 {
47     if (!(s->rregs[ESP_RSTAT] & STAT_INT)) {
48         s->rregs[ESP_RSTAT] |= STAT_INT;
49         qemu_irq_raise(s->irq);
50         trace_esp_raise_irq();
51     }
52 }
53 
54 static void esp_lower_irq(ESPState *s)
55 {
56     if (s->rregs[ESP_RSTAT] & STAT_INT) {
57         s->rregs[ESP_RSTAT] &= ~STAT_INT;
58         qemu_irq_lower(s->irq);
59         trace_esp_lower_irq();
60     }
61 }
62 
63 static void esp_raise_drq(ESPState *s)
64 {
65     qemu_irq_raise(s->irq_data);
66     trace_esp_raise_drq();
67 }
68 
69 static void esp_lower_drq(ESPState *s)
70 {
71     qemu_irq_lower(s->irq_data);
72     trace_esp_lower_drq();
73 }
74 
75 void esp_dma_enable(ESPState *s, int irq, int level)
76 {
77     if (level) {
78         s->dma_enabled = 1;
79         trace_esp_dma_enable();
80         if (s->dma_cb) {
81             s->dma_cb(s);
82             s->dma_cb = NULL;
83         }
84     } else {
85         trace_esp_dma_disable();
86         s->dma_enabled = 0;
87     }
88 }
89 
90 void esp_request_cancelled(SCSIRequest *req)
91 {
92     ESPState *s = req->hba_private;
93 
94     if (req == s->current_req) {
95         scsi_req_unref(s->current_req);
96         s->current_req = NULL;
97         s->current_dev = NULL;
98         s->async_len = 0;
99     }
100 }
101 
102 static void esp_fifo_push(Fifo8 *fifo, uint8_t val)
103 {
104     if (fifo8_num_used(fifo) == fifo->capacity) {
105         trace_esp_error_fifo_overrun();
106         return;
107     }
108 
109     fifo8_push(fifo, val);
110 }
111 
112 static uint8_t esp_fifo_pop(Fifo8 *fifo)
113 {
114     if (fifo8_is_empty(fifo)) {
115         return 0;
116     }
117 
118     return fifo8_pop(fifo);
119 }
120 
121 static uint32_t esp_fifo_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen)
122 {
123     const uint8_t *buf;
124     uint32_t n, n2;
125     int len;
126 
127     if (maxlen == 0) {
128         return 0;
129     }
130 
131     len = maxlen;
132     buf = fifo8_pop_buf(fifo, len, &n);
133     if (dest) {
134         memcpy(dest, buf, n);
135     }
136 
137     /* Add FIFO wraparound if needed */
138     len -= n;
139     len = MIN(len, fifo8_num_used(fifo));
140     if (len) {
141         buf = fifo8_pop_buf(fifo, len, &n2);
142         if (dest) {
143             memcpy(&dest[n], buf, n2);
144         }
145         n += n2;
146     }
147 
148     return n;
149 }
150 
151 static uint32_t esp_get_tc(ESPState *s)
152 {
153     uint32_t dmalen;
154 
155     dmalen = s->rregs[ESP_TCLO];
156     dmalen |= s->rregs[ESP_TCMID] << 8;
157     dmalen |= s->rregs[ESP_TCHI] << 16;
158 
159     return dmalen;
160 }
161 
162 static void esp_set_tc(ESPState *s, uint32_t dmalen)
163 {
164     uint32_t old_tc = esp_get_tc(s);
165 
166     s->rregs[ESP_TCLO] = dmalen;
167     s->rregs[ESP_TCMID] = dmalen >> 8;
168     s->rregs[ESP_TCHI] = dmalen >> 16;
169 
170     if (old_tc && dmalen == 0) {
171         s->rregs[ESP_RSTAT] |= STAT_TC;
172     }
173 }
174 
175 static uint32_t esp_get_stc(ESPState *s)
176 {
177     uint32_t dmalen;
178 
179     dmalen = s->wregs[ESP_TCLO];
180     dmalen |= s->wregs[ESP_TCMID] << 8;
181     dmalen |= s->wregs[ESP_TCHI] << 16;
182 
183     return dmalen;
184 }
185 
186 static uint8_t esp_pdma_read(ESPState *s)
187 {
188     uint8_t val;
189 
190     if (s->do_cmd) {
191         val = esp_fifo_pop(&s->cmdfifo);
192     } else {
193         val = esp_fifo_pop(&s->fifo);
194     }
195 
196     return val;
197 }
198 
199 static void esp_pdma_write(ESPState *s, uint8_t val)
200 {
201     uint32_t dmalen = esp_get_tc(s);
202 
203     if (dmalen == 0) {
204         return;
205     }
206 
207     if (s->do_cmd) {
208         esp_fifo_push(&s->cmdfifo, val);
209     } else {
210         esp_fifo_push(&s->fifo, val);
211     }
212 
213     dmalen--;
214     esp_set_tc(s, dmalen);
215 }
216 
217 static void esp_set_pdma_cb(ESPState *s, enum pdma_cb cb)
218 {
219     s->pdma_cb = cb;
220 }
221 
222 static int esp_select(ESPState *s)
223 {
224     int target;
225 
226     target = s->wregs[ESP_WBUSID] & BUSID_DID;
227 
228     s->ti_size = 0;
229 
230     if (s->current_req) {
231         /* Started a new command before the old one finished. Cancel it. */
232         scsi_req_cancel(s->current_req);
233     }
234 
235     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
236     if (!s->current_dev) {
237         /* No such drive */
238         s->rregs[ESP_RSTAT] = 0;
239         s->rregs[ESP_RINTR] = INTR_DC;
240         s->rregs[ESP_RSEQ] = SEQ_0;
241         esp_raise_irq(s);
242         return -1;
243     }
244 
245     /*
246      * Note that we deliberately don't raise the IRQ here: this will be done
247      * either in do_command_phase() for DATA OUT transfers or by the deferred
248      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
249      */
250     s->rregs[ESP_RINTR] |= INTR_FC;
251     s->rregs[ESP_RSEQ] = SEQ_CD;
252     return 0;
253 }
254 
255 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
256 {
257     uint8_t buf[ESP_CMDFIFO_SZ];
258     uint32_t dmalen, n;
259     int target;
260 
261     target = s->wregs[ESP_WBUSID] & BUSID_DID;
262     if (s->dma) {
263         dmalen = MIN(esp_get_tc(s), maxlen);
264         if (dmalen == 0) {
265             return 0;
266         }
267         if (s->dma_memory_read) {
268             s->dma_memory_read(s->dma_opaque, buf, dmalen);
269             dmalen = MIN(fifo8_num_free(&s->cmdfifo), dmalen);
270             fifo8_push_all(&s->cmdfifo, buf, dmalen);
271         } else {
272             return 0;
273         }
274     } else {
275         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
276         if (dmalen == 0) {
277             return 0;
278         }
279         n = esp_fifo_pop_buf(&s->fifo, buf, dmalen);
280         n = MIN(fifo8_num_free(&s->cmdfifo), n);
281         fifo8_push_all(&s->cmdfifo, buf, n);
282     }
283     trace_esp_get_cmd(dmalen, target);
284 
285     return dmalen;
286 }
287 
288 static void do_command_phase(ESPState *s)
289 {
290     uint32_t cmdlen;
291     int32_t datalen;
292     SCSIDevice *current_lun;
293     uint8_t buf[ESP_CMDFIFO_SZ];
294 
295     trace_esp_do_command_phase(s->lun);
296     cmdlen = fifo8_num_used(&s->cmdfifo);
297     if (!cmdlen || !s->current_dev) {
298         return;
299     }
300     esp_fifo_pop_buf(&s->cmdfifo, buf, cmdlen);
301 
302     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
303     if (!current_lun) {
304         /* No such drive */
305         s->rregs[ESP_RSTAT] = 0;
306         s->rregs[ESP_RINTR] = INTR_DC;
307         s->rregs[ESP_RSEQ] = SEQ_0;
308         esp_raise_irq(s);
309         return;
310     }
311 
312     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
313     datalen = scsi_req_enqueue(s->current_req);
314     s->ti_size = datalen;
315     fifo8_reset(&s->cmdfifo);
316     if (datalen != 0) {
317         s->rregs[ESP_RSTAT] = STAT_TC;
318         s->rregs[ESP_RSEQ] = SEQ_CD;
319         s->ti_cmd = 0;
320         esp_set_tc(s, 0);
321         if (datalen > 0) {
322             /*
323              * Switch to DATA IN phase but wait until initial data xfer is
324              * complete before raising the command completion interrupt
325              */
326             s->data_in_ready = false;
327             s->rregs[ESP_RSTAT] |= STAT_DI;
328         } else {
329             s->rregs[ESP_RSTAT] |= STAT_DO;
330             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
331             esp_raise_irq(s);
332             esp_lower_drq(s);
333         }
334         scsi_req_continue(s->current_req);
335         return;
336     }
337 }
338 
339 static void do_message_phase(ESPState *s)
340 {
341     if (s->cmdfifo_cdb_offset) {
342         uint8_t message = esp_fifo_pop(&s->cmdfifo);
343 
344         trace_esp_do_identify(message);
345         s->lun = message & 7;
346         s->cmdfifo_cdb_offset--;
347     }
348 
349     /* Ignore extended messages for now */
350     if (s->cmdfifo_cdb_offset) {
351         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
352         esp_fifo_pop_buf(&s->cmdfifo, NULL, len);
353         s->cmdfifo_cdb_offset = 0;
354     }
355 }
356 
357 static void do_cmd(ESPState *s)
358 {
359     do_message_phase(s);
360     assert(s->cmdfifo_cdb_offset == 0);
361     do_command_phase(s);
362 }
363 
364 static void satn_pdma_cb(ESPState *s)
365 {
366     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
367         s->cmdfifo_cdb_offset = 1;
368         s->do_cmd = 0;
369         do_cmd(s);
370     }
371 }
372 
373 static void handle_satn(ESPState *s)
374 {
375     int32_t cmdlen;
376 
377     if (s->dma && !s->dma_enabled) {
378         s->dma_cb = handle_satn;
379         return;
380     }
381     esp_set_pdma_cb(s, SATN_PDMA_CB);
382     if (esp_select(s) < 0) {
383         return;
384     }
385     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
386     if (cmdlen > 0) {
387         s->cmdfifo_cdb_offset = 1;
388         s->do_cmd = 0;
389         do_cmd(s);
390     } else if (cmdlen == 0) {
391         if (s->dma) {
392             esp_raise_drq(s);
393         }
394         s->do_cmd = 1;
395         /* Target present, but no cmd yet - switch to command phase */
396         s->rregs[ESP_RSEQ] = SEQ_CD;
397         s->rregs[ESP_RSTAT] = STAT_CD;
398     }
399 }
400 
401 static void s_without_satn_pdma_cb(ESPState *s)
402 {
403     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
404         s->cmdfifo_cdb_offset = 0;
405         s->do_cmd = 0;
406         do_cmd(s);
407     }
408 }
409 
410 static void handle_s_without_atn(ESPState *s)
411 {
412     int32_t cmdlen;
413 
414     if (s->dma && !s->dma_enabled) {
415         s->dma_cb = handle_s_without_atn;
416         return;
417     }
418     esp_set_pdma_cb(s, S_WITHOUT_SATN_PDMA_CB);
419     if (esp_select(s) < 0) {
420         return;
421     }
422     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
423     if (cmdlen > 0) {
424         s->cmdfifo_cdb_offset = 0;
425         s->do_cmd = 0;
426         do_cmd(s);
427     } else if (cmdlen == 0) {
428         if (s->dma) {
429             esp_raise_drq(s);
430         }
431         s->do_cmd = 1;
432         /* Target present, but no cmd yet - switch to command phase */
433         s->rregs[ESP_RSEQ] = SEQ_CD;
434         s->rregs[ESP_RSTAT] = STAT_CD;
435     }
436 }
437 
438 static void satn_stop_pdma_cb(ESPState *s)
439 {
440     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
441         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
442         s->do_cmd = 1;
443         s->cmdfifo_cdb_offset = 1;
444         s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
445         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
446         s->rregs[ESP_RSEQ] = SEQ_CD;
447         esp_raise_irq(s);
448     }
449 }
450 
451 static void handle_satn_stop(ESPState *s)
452 {
453     int32_t cmdlen;
454 
455     if (s->dma && !s->dma_enabled) {
456         s->dma_cb = handle_satn_stop;
457         return;
458     }
459     esp_set_pdma_cb(s, SATN_STOP_PDMA_CB);
460     if (esp_select(s) < 0) {
461         return;
462     }
463     cmdlen = get_cmd(s, 1);
464     if (cmdlen > 0) {
465         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
466         s->do_cmd = 1;
467         s->cmdfifo_cdb_offset = 1;
468         s->rregs[ESP_RSTAT] = STAT_MO;
469         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
470         s->rregs[ESP_RSEQ] = SEQ_MO;
471         esp_raise_irq(s);
472     } else if (cmdlen == 0) {
473         if (s->dma) {
474             esp_raise_drq(s);
475         }
476         s->do_cmd = 1;
477         /* Target present, switch to message out phase */
478         s->rregs[ESP_RSEQ] = SEQ_MO;
479         s->rregs[ESP_RSTAT] = STAT_MO;
480     }
481 }
482 
483 static void write_response_pdma_cb(ESPState *s)
484 {
485     s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
486     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
487     s->rregs[ESP_RSEQ] = SEQ_CD;
488     esp_raise_irq(s);
489 }
490 
491 static void write_response(ESPState *s)
492 {
493     uint8_t buf[2];
494 
495     trace_esp_write_response(s->status);
496 
497     buf[0] = s->status;
498     buf[1] = 0;
499 
500     if (s->dma) {
501         if (s->dma_memory_write) {
502             s->dma_memory_write(s->dma_opaque, buf, 2);
503             s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
504             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
505             s->rregs[ESP_RSEQ] = SEQ_CD;
506         } else {
507             esp_set_pdma_cb(s, WRITE_RESPONSE_PDMA_CB);
508             esp_raise_drq(s);
509             return;
510         }
511     } else {
512         fifo8_reset(&s->fifo);
513         fifo8_push_all(&s->fifo, buf, 2);
514         s->rregs[ESP_RFLAGS] = 2;
515     }
516     esp_raise_irq(s);
517 }
518 
519 static void esp_dma_done(ESPState *s)
520 {
521     s->rregs[ESP_RSTAT] |= STAT_TC;
522     s->rregs[ESP_RINTR] |= INTR_BS;
523     s->rregs[ESP_RFLAGS] = 0;
524     esp_set_tc(s, 0);
525     esp_raise_irq(s);
526 }
527 
528 static void do_dma_pdma_cb(ESPState *s)
529 {
530     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
531     int len;
532     uint32_t n;
533 
534     if (s->do_cmd) {
535         /* Ensure we have received complete command after SATN and stop */
536         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
537             return;
538         }
539 
540         s->ti_size = 0;
541         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
542             /* No command received */
543             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
544                 return;
545             }
546 
547             /* Command has been received */
548             s->do_cmd = 0;
549             do_cmd(s);
550         } else {
551             /*
552              * Extra message out bytes received: update cmdfifo_cdb_offset
553              * and then switch to command phase
554              */
555             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
556             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
557             s->rregs[ESP_RSEQ] = SEQ_CD;
558             s->rregs[ESP_RINTR] |= INTR_BS;
559             esp_raise_irq(s);
560         }
561         return;
562     }
563 
564     if (!s->current_req) {
565         return;
566     }
567 
568     if (to_device) {
569         /* Copy FIFO data to device */
570         len = MIN(s->async_len, ESP_FIFO_SZ);
571         len = MIN(len, fifo8_num_used(&s->fifo));
572         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
573         s->async_buf += n;
574         s->async_len -= n;
575         s->ti_size += n;
576 
577         if (n < len) {
578             /* Unaligned accesses can cause FIFO wraparound */
579             len = len - n;
580             n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
581             s->async_buf += n;
582             s->async_len -= n;
583             s->ti_size += n;
584         }
585 
586         if (s->async_len == 0) {
587             scsi_req_continue(s->current_req);
588             return;
589         }
590 
591         if (esp_get_tc(s) == 0) {
592             esp_lower_drq(s);
593             esp_dma_done(s);
594         }
595 
596         return;
597     } else {
598         if (s->async_len == 0) {
599             /* Defer until the scsi layer has completed */
600             scsi_req_continue(s->current_req);
601             s->data_in_ready = false;
602             return;
603         }
604 
605         if (esp_get_tc(s) == 0) {
606             esp_lower_drq(s);
607             esp_dma_done(s);
608         }
609 
610         /* Copy device data to FIFO */
611         len = MIN(s->async_len, esp_get_tc(s));
612         len = MIN(len, fifo8_num_free(&s->fifo));
613         fifo8_push_all(&s->fifo, s->async_buf, len);
614         s->async_buf += len;
615         s->async_len -= len;
616         s->ti_size -= len;
617         esp_set_tc(s, esp_get_tc(s) - len);
618     }
619 }
620 
621 static void esp_do_dma(ESPState *s)
622 {
623     uint32_t len, cmdlen;
624     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
625     uint8_t buf[ESP_CMDFIFO_SZ];
626 
627     len = esp_get_tc(s);
628     if (s->do_cmd) {
629         /*
630          * handle_ti_cmd() case: esp_do_dma() is called only from
631          * handle_ti_cmd() with do_cmd != NULL (see the assert())
632          */
633         cmdlen = fifo8_num_used(&s->cmdfifo);
634         trace_esp_do_dma(cmdlen, len);
635         if (s->dma_memory_read) {
636             len = MIN(len, fifo8_num_free(&s->cmdfifo));
637             s->dma_memory_read(s->dma_opaque, buf, len);
638             fifo8_push_all(&s->cmdfifo, buf, len);
639         } else {
640             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
641             esp_raise_drq(s);
642             return;
643         }
644         trace_esp_handle_ti_cmd(cmdlen);
645         s->ti_size = 0;
646         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
647             /* No command received */
648             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
649                 return;
650             }
651 
652             /* Command has been received */
653             s->do_cmd = 0;
654             do_cmd(s);
655         } else {
656             /*
657              * Extra message out bytes received: update cmdfifo_cdb_offset
658              * and then switch to command phase
659              */
660             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
661             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
662             s->rregs[ESP_RSEQ] = SEQ_CD;
663             s->rregs[ESP_RINTR] |= INTR_BS;
664             esp_raise_irq(s);
665         }
666         return;
667     }
668     if (!s->current_req) {
669         return;
670     }
671     if (s->async_len == 0) {
672         /* Defer until data is available.  */
673         return;
674     }
675     if (len > s->async_len) {
676         len = s->async_len;
677     }
678     if (to_device) {
679         if (s->dma_memory_read) {
680             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
681 
682             esp_set_tc(s, esp_get_tc(s) - len);
683             s->async_buf += len;
684             s->async_len -= len;
685             s->ti_size += len;
686 
687             if (s->async_len == 0) {
688                 scsi_req_continue(s->current_req);
689                 /*
690                  * If there is still data to be read from the device then
691                  * complete the DMA operation immediately.  Otherwise defer
692                  * until the scsi layer has completed.
693                  */
694                 return;
695             }
696 
697             /* Partially filled a scsi buffer. Complete immediately.  */
698             esp_dma_done(s);
699             esp_lower_drq(s);
700         } else {
701             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
702             esp_raise_drq(s);
703         }
704     } else {
705         if (s->dma_memory_write) {
706             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
707 
708             esp_set_tc(s, esp_get_tc(s) - len);
709             s->async_buf += len;
710             s->async_len -= len;
711             s->ti_size -= len;
712 
713             if (s->async_len == 0) {
714                 scsi_req_continue(s->current_req);
715                 /*
716                  * If there is still data to be read from the device then
717                  * complete the DMA operation immediately.  Otherwise defer
718                  * until the scsi layer has completed.
719                  */
720                 if (esp_get_tc(s) != 0 || s->ti_size == 0) {
721                     return;
722                 }
723             }
724 
725             /* Partially filled a scsi buffer. Complete immediately.  */
726             esp_dma_done(s);
727             esp_lower_drq(s);
728         } else {
729             /* Adjust TC for any leftover data in the FIFO */
730             if (!fifo8_is_empty(&s->fifo)) {
731                 esp_set_tc(s, esp_get_tc(s) - fifo8_num_used(&s->fifo));
732             }
733 
734             /* Copy device data to FIFO */
735             len = MIN(len, fifo8_num_free(&s->fifo));
736             fifo8_push_all(&s->fifo, s->async_buf, len);
737             s->async_buf += len;
738             s->async_len -= len;
739             s->ti_size -= len;
740 
741             /*
742              * MacOS toolbox uses a TI length of 16 bytes for all commands, so
743              * commands shorter than this must be padded accordingly
744              */
745             if (len < esp_get_tc(s) && esp_get_tc(s) <= ESP_FIFO_SZ) {
746                 while (fifo8_num_used(&s->fifo) < ESP_FIFO_SZ) {
747                     esp_fifo_push(&s->fifo, 0);
748                     len++;
749                 }
750             }
751 
752             esp_set_tc(s, esp_get_tc(s) - len);
753             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
754             esp_raise_drq(s);
755         }
756     }
757 }
758 
759 static void esp_do_nodma(ESPState *s)
760 {
761     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
762     uint32_t cmdlen;
763     int len;
764 
765     if (s->do_cmd) {
766         cmdlen = fifo8_num_used(&s->cmdfifo);
767         trace_esp_handle_ti_cmd(cmdlen);
768         s->ti_size = 0;
769         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
770             /* No command received */
771             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
772                 return;
773             }
774 
775             /* Command has been received */
776             s->do_cmd = 0;
777             do_cmd(s);
778         } else {
779             /*
780              * Extra message out bytes received: update cmdfifo_cdb_offset
781              * and then switch to command phase
782              */
783             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
784             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
785             s->rregs[ESP_RSEQ] = SEQ_CD;
786             s->rregs[ESP_RINTR] |= INTR_BS;
787             esp_raise_irq(s);
788         }
789         return;
790     }
791 
792     if (!s->current_req) {
793         return;
794     }
795 
796     if (s->async_len == 0) {
797         /* Defer until data is available.  */
798         return;
799     }
800 
801     if (to_device) {
802         len = MIN(s->async_len, ESP_FIFO_SZ);
803         len = MIN(len, fifo8_num_used(&s->fifo));
804         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
805         s->async_buf += len;
806         s->async_len -= len;
807         s->ti_size += len;
808     } else {
809         if (fifo8_is_empty(&s->fifo)) {
810             fifo8_push(&s->fifo, s->async_buf[0]);
811             s->async_buf++;
812             s->async_len--;
813             s->ti_size--;
814         }
815     }
816 
817     if (s->async_len == 0) {
818         scsi_req_continue(s->current_req);
819         return;
820     }
821 
822     s->rregs[ESP_RINTR] |= INTR_BS;
823     esp_raise_irq(s);
824 }
825 
826 static void esp_pdma_cb(ESPState *s)
827 {
828     switch (s->pdma_cb) {
829     case SATN_PDMA_CB:
830         satn_pdma_cb(s);
831         break;
832     case S_WITHOUT_SATN_PDMA_CB:
833         s_without_satn_pdma_cb(s);
834         break;
835     case SATN_STOP_PDMA_CB:
836         satn_stop_pdma_cb(s);
837         break;
838     case WRITE_RESPONSE_PDMA_CB:
839         write_response_pdma_cb(s);
840         break;
841     case DO_DMA_PDMA_CB:
842         do_dma_pdma_cb(s);
843         break;
844     default:
845         g_assert_not_reached();
846     }
847 }
848 
849 void esp_command_complete(SCSIRequest *req, size_t resid)
850 {
851     ESPState *s = req->hba_private;
852     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
853 
854     trace_esp_command_complete();
855 
856     /*
857      * Non-DMA transfers from the target will leave the last byte in
858      * the FIFO so don't reset ti_size in this case
859      */
860     if (s->dma || to_device) {
861         if (s->ti_size != 0) {
862             trace_esp_command_complete_unexpected();
863         }
864         s->ti_size = 0;
865     }
866 
867     s->async_len = 0;
868     if (req->status) {
869         trace_esp_command_complete_fail();
870     }
871     s->status = req->status;
872 
873     /*
874      * If the transfer is finished, switch to status phase. For non-DMA
875      * transfers from the target the last byte is still in the FIFO
876      */
877     if (s->ti_size == 0) {
878         s->rregs[ESP_RSTAT] &= ~7;
879         s->rregs[ESP_RSTAT] |= STAT_ST;
880         esp_dma_done(s);
881         esp_lower_drq(s);
882     }
883 
884     if (s->current_req) {
885         scsi_req_unref(s->current_req);
886         s->current_req = NULL;
887         s->current_dev = NULL;
888     }
889 }
890 
891 void esp_transfer_data(SCSIRequest *req, uint32_t len)
892 {
893     ESPState *s = req->hba_private;
894     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
895     uint32_t dmalen = esp_get_tc(s);
896 
897     assert(!s->do_cmd);
898     trace_esp_transfer_data(dmalen, s->ti_size);
899     s->async_len = len;
900     s->async_buf = scsi_req_get_buf(req);
901 
902     if (!to_device && !s->data_in_ready) {
903         /*
904          * Initial incoming data xfer is complete so raise command
905          * completion interrupt
906          */
907         s->data_in_ready = true;
908         s->rregs[ESP_RSTAT] |= STAT_TC;
909         s->rregs[ESP_RINTR] |= INTR_BS;
910         esp_raise_irq(s);
911     }
912 
913     if (s->ti_cmd == 0) {
914         /*
915          * Always perform the initial transfer upon reception of the next TI
916          * command to ensure the DMA/non-DMA status of the command is correct.
917          * It is not possible to use s->dma directly in the section below as
918          * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
919          * async data transfer is delayed then s->dma is set incorrectly.
920          */
921         return;
922     }
923 
924     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
925         if (dmalen) {
926             esp_do_dma(s);
927         } else if (s->ti_size <= 0) {
928             /*
929              * If this was the last part of a DMA transfer then the
930              * completion interrupt is deferred to here.
931              */
932             esp_dma_done(s);
933             esp_lower_drq(s);
934         }
935     } else if (s->ti_cmd == CMD_TI) {
936         esp_do_nodma(s);
937     }
938 }
939 
940 static void handle_ti(ESPState *s)
941 {
942     uint32_t dmalen;
943 
944     if (s->dma && !s->dma_enabled) {
945         s->dma_cb = handle_ti;
946         return;
947     }
948 
949     s->ti_cmd = s->rregs[ESP_CMD];
950     if (s->dma) {
951         dmalen = esp_get_tc(s);
952         trace_esp_handle_ti(dmalen);
953         s->rregs[ESP_RSTAT] &= ~STAT_TC;
954         esp_do_dma(s);
955     } else {
956         trace_esp_handle_ti(s->ti_size);
957         esp_do_nodma(s);
958     }
959 }
960 
961 void esp_hard_reset(ESPState *s)
962 {
963     memset(s->rregs, 0, ESP_REGS);
964     memset(s->wregs, 0, ESP_REGS);
965     s->tchi_written = 0;
966     s->ti_size = 0;
967     s->async_len = 0;
968     fifo8_reset(&s->fifo);
969     fifo8_reset(&s->cmdfifo);
970     s->dma = 0;
971     s->do_cmd = 0;
972     s->dma_cb = NULL;
973 
974     s->rregs[ESP_CFG1] = 7;
975 }
976 
977 static void esp_soft_reset(ESPState *s)
978 {
979     qemu_irq_lower(s->irq);
980     qemu_irq_lower(s->irq_data);
981     esp_hard_reset(s);
982 }
983 
984 static void esp_bus_reset(ESPState *s)
985 {
986     bus_cold_reset(BUS(&s->bus));
987 }
988 
989 static void parent_esp_reset(ESPState *s, int irq, int level)
990 {
991     if (level) {
992         esp_soft_reset(s);
993     }
994 }
995 
996 static void esp_run_cmd(ESPState *s)
997 {
998     uint8_t cmd = s->rregs[ESP_CMD];
999 
1000     if (cmd & CMD_DMA) {
1001         s->dma = 1;
1002         /* Reload DMA counter.  */
1003         if (esp_get_stc(s) == 0) {
1004             esp_set_tc(s, 0x10000);
1005         } else {
1006             esp_set_tc(s, esp_get_stc(s));
1007         }
1008     } else {
1009         s->dma = 0;
1010     }
1011     switch (cmd & CMD_CMD) {
1012     case CMD_NOP:
1013         trace_esp_mem_writeb_cmd_nop(cmd);
1014         break;
1015     case CMD_FLUSH:
1016         trace_esp_mem_writeb_cmd_flush(cmd);
1017         fifo8_reset(&s->fifo);
1018         break;
1019     case CMD_RESET:
1020         trace_esp_mem_writeb_cmd_reset(cmd);
1021         esp_soft_reset(s);
1022         break;
1023     case CMD_BUSRESET:
1024         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1025         esp_bus_reset(s);
1026         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1027             s->rregs[ESP_RINTR] |= INTR_RST;
1028             esp_raise_irq(s);
1029         }
1030         break;
1031     case CMD_TI:
1032         trace_esp_mem_writeb_cmd_ti(cmd);
1033         handle_ti(s);
1034         break;
1035     case CMD_ICCS:
1036         trace_esp_mem_writeb_cmd_iccs(cmd);
1037         write_response(s);
1038         s->rregs[ESP_RINTR] |= INTR_FC;
1039         s->rregs[ESP_RSTAT] |= STAT_MI;
1040         break;
1041     case CMD_MSGACC:
1042         trace_esp_mem_writeb_cmd_msgacc(cmd);
1043         s->rregs[ESP_RINTR] |= INTR_DC;
1044         s->rregs[ESP_RSEQ] = 0;
1045         s->rregs[ESP_RFLAGS] = 0;
1046         esp_raise_irq(s);
1047         break;
1048     case CMD_PAD:
1049         trace_esp_mem_writeb_cmd_pad(cmd);
1050         s->rregs[ESP_RSTAT] = STAT_TC;
1051         s->rregs[ESP_RINTR] |= INTR_FC;
1052         s->rregs[ESP_RSEQ] = 0;
1053         break;
1054     case CMD_SATN:
1055         trace_esp_mem_writeb_cmd_satn(cmd);
1056         break;
1057     case CMD_RSTATN:
1058         trace_esp_mem_writeb_cmd_rstatn(cmd);
1059         break;
1060     case CMD_SEL:
1061         trace_esp_mem_writeb_cmd_sel(cmd);
1062         handle_s_without_atn(s);
1063         break;
1064     case CMD_SELATN:
1065         trace_esp_mem_writeb_cmd_selatn(cmd);
1066         handle_satn(s);
1067         break;
1068     case CMD_SELATNS:
1069         trace_esp_mem_writeb_cmd_selatns(cmd);
1070         handle_satn_stop(s);
1071         break;
1072     case CMD_ENSEL:
1073         trace_esp_mem_writeb_cmd_ensel(cmd);
1074         s->rregs[ESP_RINTR] = 0;
1075         break;
1076     case CMD_DISSEL:
1077         trace_esp_mem_writeb_cmd_dissel(cmd);
1078         s->rregs[ESP_RINTR] = 0;
1079         esp_raise_irq(s);
1080         break;
1081     default:
1082         trace_esp_error_unhandled_command(cmd);
1083         break;
1084     }
1085 }
1086 
1087 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1088 {
1089     uint32_t val;
1090 
1091     switch (saddr) {
1092     case ESP_FIFO:
1093         if (s->dma_memory_read && s->dma_memory_write &&
1094                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1095             /* Data out.  */
1096             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1097             s->rregs[ESP_FIFO] = 0;
1098         } else {
1099             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1100                 if (s->ti_size) {
1101                     esp_do_nodma(s);
1102                 } else {
1103                     /*
1104                      * The last byte of a non-DMA transfer has been read out
1105                      * of the FIFO so switch to status phase
1106                      */
1107                     s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
1108                 }
1109             }
1110             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1111         }
1112         val = s->rregs[ESP_FIFO];
1113         break;
1114     case ESP_RINTR:
1115         /*
1116          * Clear sequence step, interrupt register and all status bits
1117          * except TC
1118          */
1119         val = s->rregs[ESP_RINTR];
1120         s->rregs[ESP_RINTR] = 0;
1121         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1122         /*
1123          * According to the datasheet ESP_RSEQ should be cleared, but as the
1124          * emulation currently defers information transfers to the next TI
1125          * command leave it for now so that pedantic guests such as the old
1126          * Linux 2.6 driver see the correct flags before the next SCSI phase
1127          * transition.
1128          *
1129          * s->rregs[ESP_RSEQ] = SEQ_0;
1130          */
1131         esp_lower_irq(s);
1132         break;
1133     case ESP_TCHI:
1134         /* Return the unique id if the value has never been written */
1135         if (!s->tchi_written) {
1136             val = s->chip_id;
1137         } else {
1138             val = s->rregs[saddr];
1139         }
1140         break;
1141      case ESP_RFLAGS:
1142         /* Bottom 5 bits indicate number of bytes in FIFO */
1143         val = fifo8_num_used(&s->fifo);
1144         break;
1145     default:
1146         val = s->rregs[saddr];
1147         break;
1148     }
1149 
1150     trace_esp_mem_readb(saddr, val);
1151     return val;
1152 }
1153 
1154 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1155 {
1156     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1157     switch (saddr) {
1158     case ESP_TCHI:
1159         s->tchi_written = true;
1160         /* fall through */
1161     case ESP_TCLO:
1162     case ESP_TCMID:
1163         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1164         break;
1165     case ESP_FIFO:
1166         if (s->do_cmd) {
1167             esp_fifo_push(&s->cmdfifo, val);
1168 
1169             /*
1170              * If any unexpected message out/command phase data is
1171              * transferred using non-DMA, raise the interrupt
1172              */
1173             if (s->rregs[ESP_CMD] == CMD_TI) {
1174                 s->rregs[ESP_RINTR] |= INTR_BS;
1175                 esp_raise_irq(s);
1176             }
1177         } else {
1178             esp_fifo_push(&s->fifo, val);
1179         }
1180         break;
1181     case ESP_CMD:
1182         s->rregs[saddr] = val;
1183         esp_run_cmd(s);
1184         break;
1185     case ESP_WBUSID ... ESP_WSYNO:
1186         break;
1187     case ESP_CFG1:
1188     case ESP_CFG2: case ESP_CFG3:
1189     case ESP_RES3: case ESP_RES4:
1190         s->rregs[saddr] = val;
1191         break;
1192     case ESP_WCCF ... ESP_WTEST:
1193         break;
1194     default:
1195         trace_esp_error_invalid_write(val, saddr);
1196         return;
1197     }
1198     s->wregs[saddr] = val;
1199 }
1200 
1201 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1202                             unsigned size, bool is_write,
1203                             MemTxAttrs attrs)
1204 {
1205     return (size == 1) || (is_write && size == 4);
1206 }
1207 
1208 static bool esp_is_before_version_5(void *opaque, int version_id)
1209 {
1210     ESPState *s = ESP(opaque);
1211 
1212     version_id = MIN(version_id, s->mig_version_id);
1213     return version_id < 5;
1214 }
1215 
1216 static bool esp_is_version_5(void *opaque, int version_id)
1217 {
1218     ESPState *s = ESP(opaque);
1219 
1220     version_id = MIN(version_id, s->mig_version_id);
1221     return version_id >= 5;
1222 }
1223 
1224 static bool esp_is_version_6(void *opaque, int version_id)
1225 {
1226     ESPState *s = ESP(opaque);
1227 
1228     version_id = MIN(version_id, s->mig_version_id);
1229     return version_id >= 6;
1230 }
1231 
1232 int esp_pre_save(void *opaque)
1233 {
1234     ESPState *s = ESP(object_resolve_path_component(
1235                       OBJECT(opaque), "esp"));
1236 
1237     s->mig_version_id = vmstate_esp.version_id;
1238     return 0;
1239 }
1240 
1241 static int esp_post_load(void *opaque, int version_id)
1242 {
1243     ESPState *s = ESP(opaque);
1244     int len, i;
1245 
1246     version_id = MIN(version_id, s->mig_version_id);
1247 
1248     if (version_id < 5) {
1249         esp_set_tc(s, s->mig_dma_left);
1250 
1251         /* Migrate ti_buf to fifo */
1252         len = s->mig_ti_wptr - s->mig_ti_rptr;
1253         for (i = 0; i < len; i++) {
1254             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1255         }
1256 
1257         /* Migrate cmdbuf to cmdfifo */
1258         for (i = 0; i < s->mig_cmdlen; i++) {
1259             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1260         }
1261     }
1262 
1263     s->mig_version_id = vmstate_esp.version_id;
1264     return 0;
1265 }
1266 
1267 /*
1268  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1269  * guest CPU to perform the transfers between the SCSI bus and memory
1270  * itself. This is indicated by the dma_memory_read and dma_memory_write
1271  * functions being NULL (in contrast to the ESP PCI device) whilst
1272  * dma_enabled is still set.
1273  */
1274 
1275 static bool esp_pdma_needed(void *opaque)
1276 {
1277     ESPState *s = ESP(opaque);
1278 
1279     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1280            s->dma_enabled;
1281 }
1282 
1283 static const VMStateDescription vmstate_esp_pdma = {
1284     .name = "esp/pdma",
1285     .version_id = 0,
1286     .minimum_version_id = 0,
1287     .needed = esp_pdma_needed,
1288     .fields = (const VMStateField[]) {
1289         VMSTATE_UINT8(pdma_cb, ESPState),
1290         VMSTATE_END_OF_LIST()
1291     }
1292 };
1293 
1294 const VMStateDescription vmstate_esp = {
1295     .name = "esp",
1296     .version_id = 6,
1297     .minimum_version_id = 3,
1298     .post_load = esp_post_load,
1299     .fields = (const VMStateField[]) {
1300         VMSTATE_BUFFER(rregs, ESPState),
1301         VMSTATE_BUFFER(wregs, ESPState),
1302         VMSTATE_INT32(ti_size, ESPState),
1303         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1304         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1305         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1306         VMSTATE_UINT32(status, ESPState),
1307         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1308                             esp_is_before_version_5),
1309         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1310                           esp_is_before_version_5),
1311         VMSTATE_UINT32(dma, ESPState),
1312         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1313                               esp_is_before_version_5, 0, 16),
1314         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1315                               esp_is_before_version_5, 16,
1316                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1317         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1318         VMSTATE_UINT32(do_cmd, ESPState),
1319         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1320         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1321         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1322         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1323         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1324         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1325         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1326         VMSTATE_END_OF_LIST()
1327     },
1328     .subsections = (const VMStateDescription * const []) {
1329         &vmstate_esp_pdma,
1330         NULL
1331     }
1332 };
1333 
1334 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1335                                  uint64_t val, unsigned int size)
1336 {
1337     SysBusESPState *sysbus = opaque;
1338     ESPState *s = ESP(&sysbus->esp);
1339     uint32_t saddr;
1340 
1341     saddr = addr >> sysbus->it_shift;
1342     esp_reg_write(s, saddr, val);
1343 }
1344 
1345 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1346                                     unsigned int size)
1347 {
1348     SysBusESPState *sysbus = opaque;
1349     ESPState *s = ESP(&sysbus->esp);
1350     uint32_t saddr;
1351 
1352     saddr = addr >> sysbus->it_shift;
1353     return esp_reg_read(s, saddr);
1354 }
1355 
1356 static const MemoryRegionOps sysbus_esp_mem_ops = {
1357     .read = sysbus_esp_mem_read,
1358     .write = sysbus_esp_mem_write,
1359     .endianness = DEVICE_NATIVE_ENDIAN,
1360     .valid.accepts = esp_mem_accepts,
1361 };
1362 
1363 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1364                                   uint64_t val, unsigned int size)
1365 {
1366     SysBusESPState *sysbus = opaque;
1367     ESPState *s = ESP(&sysbus->esp);
1368 
1369     trace_esp_pdma_write(size);
1370 
1371     switch (size) {
1372     case 1:
1373         esp_pdma_write(s, val);
1374         break;
1375     case 2:
1376         esp_pdma_write(s, val >> 8);
1377         esp_pdma_write(s, val);
1378         break;
1379     }
1380     esp_pdma_cb(s);
1381 }
1382 
1383 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1384                                      unsigned int size)
1385 {
1386     SysBusESPState *sysbus = opaque;
1387     ESPState *s = ESP(&sysbus->esp);
1388     uint64_t val = 0;
1389 
1390     trace_esp_pdma_read(size);
1391 
1392     switch (size) {
1393     case 1:
1394         val = esp_pdma_read(s);
1395         break;
1396     case 2:
1397         val = esp_pdma_read(s);
1398         val = (val << 8) | esp_pdma_read(s);
1399         break;
1400     }
1401     if (fifo8_num_used(&s->fifo) < 2) {
1402         esp_pdma_cb(s);
1403     }
1404     return val;
1405 }
1406 
1407 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1408 {
1409     ESPState *s = container_of(req->bus, ESPState, bus);
1410 
1411     scsi_req_ref(req);
1412     s->current_req = req;
1413     return s;
1414 }
1415 
1416 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1417     .read = sysbus_esp_pdma_read,
1418     .write = sysbus_esp_pdma_write,
1419     .endianness = DEVICE_NATIVE_ENDIAN,
1420     .valid.min_access_size = 1,
1421     .valid.max_access_size = 4,
1422     .impl.min_access_size = 1,
1423     .impl.max_access_size = 2,
1424 };
1425 
1426 static const struct SCSIBusInfo esp_scsi_info = {
1427     .tcq = false,
1428     .max_target = ESP_MAX_DEVS,
1429     .max_lun = 7,
1430 
1431     .load_request = esp_load_request,
1432     .transfer_data = esp_transfer_data,
1433     .complete = esp_command_complete,
1434     .cancel = esp_request_cancelled
1435 };
1436 
1437 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1438 {
1439     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1440     ESPState *s = ESP(&sysbus->esp);
1441 
1442     switch (irq) {
1443     case 0:
1444         parent_esp_reset(s, irq, level);
1445         break;
1446     case 1:
1447         esp_dma_enable(s, irq, level);
1448         break;
1449     }
1450 }
1451 
1452 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1453 {
1454     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1455     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1456     ESPState *s = ESP(&sysbus->esp);
1457 
1458     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1459         return;
1460     }
1461 
1462     sysbus_init_irq(sbd, &s->irq);
1463     sysbus_init_irq(sbd, &s->irq_data);
1464     assert(sysbus->it_shift != -1);
1465 
1466     s->chip_id = TCHI_FAS100A;
1467     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1468                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1469     sysbus_init_mmio(sbd, &sysbus->iomem);
1470     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1471                           sysbus, "esp-pdma", 4);
1472     sysbus_init_mmio(sbd, &sysbus->pdma);
1473 
1474     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1475 
1476     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1477 }
1478 
1479 static void sysbus_esp_hard_reset(DeviceState *dev)
1480 {
1481     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1482     ESPState *s = ESP(&sysbus->esp);
1483 
1484     esp_hard_reset(s);
1485 }
1486 
1487 static void sysbus_esp_init(Object *obj)
1488 {
1489     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1490 
1491     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1492 }
1493 
1494 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1495     .name = "sysbusespscsi",
1496     .version_id = 2,
1497     .minimum_version_id = 1,
1498     .pre_save = esp_pre_save,
1499     .fields = (const VMStateField[]) {
1500         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1501         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1502         VMSTATE_END_OF_LIST()
1503     }
1504 };
1505 
1506 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1507 {
1508     DeviceClass *dc = DEVICE_CLASS(klass);
1509 
1510     dc->realize = sysbus_esp_realize;
1511     dc->reset = sysbus_esp_hard_reset;
1512     dc->vmsd = &vmstate_sysbus_esp_scsi;
1513     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1514 }
1515 
1516 static const TypeInfo sysbus_esp_info = {
1517     .name          = TYPE_SYSBUS_ESP,
1518     .parent        = TYPE_SYS_BUS_DEVICE,
1519     .instance_init = sysbus_esp_init,
1520     .instance_size = sizeof(SysBusESPState),
1521     .class_init    = sysbus_esp_class_init,
1522 };
1523 
1524 static void esp_finalize(Object *obj)
1525 {
1526     ESPState *s = ESP(obj);
1527 
1528     fifo8_destroy(&s->fifo);
1529     fifo8_destroy(&s->cmdfifo);
1530 }
1531 
1532 static void esp_init(Object *obj)
1533 {
1534     ESPState *s = ESP(obj);
1535 
1536     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1537     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1538 }
1539 
1540 static void esp_class_init(ObjectClass *klass, void *data)
1541 {
1542     DeviceClass *dc = DEVICE_CLASS(klass);
1543 
1544     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1545     dc->user_creatable = false;
1546     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1547 }
1548 
1549 static const TypeInfo esp_info = {
1550     .name = TYPE_ESP,
1551     .parent = TYPE_DEVICE,
1552     .instance_init = esp_init,
1553     .instance_finalize = esp_finalize,
1554     .instance_size = sizeof(ESPState),
1555     .class_init = esp_class_init,
1556 };
1557 
1558 static void esp_register_types(void)
1559 {
1560     type_register_static(&sysbus_esp_info);
1561     type_register_static(&esp_info);
1562 }
1563 
1564 type_init(esp_register_types)
1565