xref: /qemu/hw/scsi/esp.c (revision e7a661d1170b7b684485b467d443566ee80376d0)
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 const char *esp_phase_names[8] = {
187     "DATA OUT", "DATA IN", "COMMAND", "STATUS",
188     "(reserved)", "(reserved)", "MESSAGE OUT", "MESSAGE IN"
189 };
190 
191 static void esp_set_phase(ESPState *s, uint8_t phase)
192 {
193     s->rregs[ESP_RSTAT] &= ~7;
194     s->rregs[ESP_RSTAT] |= phase;
195 
196     trace_esp_set_phase(esp_phase_names[phase]);
197 }
198 
199 static uint8_t esp_pdma_read(ESPState *s)
200 {
201     uint8_t val;
202 
203     val = esp_fifo_pop(&s->fifo);
204     return val;
205 }
206 
207 static void esp_pdma_write(ESPState *s, uint8_t val)
208 {
209     uint32_t dmalen = esp_get_tc(s);
210 
211     if (dmalen == 0) {
212         return;
213     }
214 
215     esp_fifo_push(&s->fifo, val);
216 
217     dmalen--;
218     esp_set_tc(s, dmalen);
219 }
220 
221 static void esp_set_pdma_cb(ESPState *s, enum pdma_cb cb)
222 {
223     s->pdma_cb = cb;
224 }
225 
226 static int esp_select(ESPState *s)
227 {
228     int target;
229 
230     target = s->wregs[ESP_WBUSID] & BUSID_DID;
231 
232     s->ti_size = 0;
233 
234     if (s->current_req) {
235         /* Started a new command before the old one finished. Cancel it. */
236         scsi_req_cancel(s->current_req);
237     }
238 
239     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
240     if (!s->current_dev) {
241         /* No such drive */
242         s->rregs[ESP_RSTAT] = 0;
243         s->rregs[ESP_RINTR] = INTR_DC;
244         s->rregs[ESP_RSEQ] = SEQ_0;
245         esp_raise_irq(s);
246         return -1;
247     }
248 
249     /*
250      * Note that we deliberately don't raise the IRQ here: this will be done
251      * either in do_command_phase() for DATA OUT transfers or by the deferred
252      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
253      */
254     s->rregs[ESP_RINTR] |= INTR_FC;
255     s->rregs[ESP_RSEQ] = SEQ_CD;
256     return 0;
257 }
258 
259 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
260 {
261     uint8_t buf[ESP_CMDFIFO_SZ];
262     uint32_t dmalen, n;
263     int target;
264 
265     target = s->wregs[ESP_WBUSID] & BUSID_DID;
266     if (s->dma) {
267         dmalen = MIN(esp_get_tc(s), maxlen);
268         if (dmalen == 0) {
269             return 0;
270         }
271         if (s->dma_memory_read) {
272             s->dma_memory_read(s->dma_opaque, buf, dmalen);
273             dmalen = MIN(fifo8_num_free(&s->cmdfifo), dmalen);
274             fifo8_push_all(&s->cmdfifo, buf, dmalen);
275             esp_set_tc(s, esp_get_tc(s) - dmalen);
276         } else {
277             return 0;
278         }
279     } else {
280         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
281         if (dmalen == 0) {
282             return 0;
283         }
284         n = esp_fifo_pop_buf(&s->fifo, buf, dmalen);
285         n = MIN(fifo8_num_free(&s->cmdfifo), n);
286         fifo8_push_all(&s->cmdfifo, buf, n);
287     }
288     trace_esp_get_cmd(dmalen, target);
289 
290     return dmalen;
291 }
292 
293 static void do_command_phase(ESPState *s)
294 {
295     uint32_t cmdlen;
296     int32_t datalen;
297     SCSIDevice *current_lun;
298     uint8_t buf[ESP_CMDFIFO_SZ];
299 
300     trace_esp_do_command_phase(s->lun);
301     cmdlen = fifo8_num_used(&s->cmdfifo);
302     if (!cmdlen || !s->current_dev) {
303         return;
304     }
305     esp_fifo_pop_buf(&s->cmdfifo, buf, cmdlen);
306 
307     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
308     if (!current_lun) {
309         /* No such drive */
310         s->rregs[ESP_RSTAT] = 0;
311         s->rregs[ESP_RINTR] = INTR_DC;
312         s->rregs[ESP_RSEQ] = SEQ_0;
313         esp_raise_irq(s);
314         return;
315     }
316 
317     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
318     datalen = scsi_req_enqueue(s->current_req);
319     s->ti_size = datalen;
320     fifo8_reset(&s->cmdfifo);
321     if (datalen != 0) {
322         s->ti_cmd = 0;
323         if (datalen > 0) {
324             /*
325              * Switch to DATA IN phase but wait until initial data xfer is
326              * complete before raising the command completion interrupt
327              */
328             s->data_in_ready = false;
329             esp_set_phase(s, STAT_DI);
330         } else {
331             esp_set_phase(s, STAT_DO);
332             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
333             esp_raise_irq(s);
334             esp_lower_drq(s);
335         }
336         scsi_req_continue(s->current_req);
337         return;
338     }
339 }
340 
341 static void do_message_phase(ESPState *s)
342 {
343     if (s->cmdfifo_cdb_offset) {
344         uint8_t message = esp_fifo_pop(&s->cmdfifo);
345 
346         trace_esp_do_identify(message);
347         s->lun = message & 7;
348         s->cmdfifo_cdb_offset--;
349     }
350 
351     /* Ignore extended messages for now */
352     if (s->cmdfifo_cdb_offset) {
353         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
354         esp_fifo_pop_buf(&s->cmdfifo, NULL, len);
355         s->cmdfifo_cdb_offset = 0;
356     }
357 }
358 
359 static void do_cmd(ESPState *s)
360 {
361     do_message_phase(s);
362     assert(s->cmdfifo_cdb_offset == 0);
363     do_command_phase(s);
364 }
365 
366 static void satn_pdma_cb(ESPState *s)
367 {
368     uint8_t buf[ESP_FIFO_SZ];
369     int n;
370 
371     /* Copy FIFO into cmdfifo */
372     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
373     n = MIN(fifo8_num_free(&s->cmdfifo), n);
374     fifo8_push_all(&s->cmdfifo, buf, n);
375 
376     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
377         s->cmdfifo_cdb_offset = 1;
378         s->do_cmd = 0;
379         do_cmd(s);
380     }
381 }
382 
383 static void handle_satn(ESPState *s)
384 {
385     int32_t cmdlen;
386 
387     if (s->dma && !s->dma_enabled) {
388         s->dma_cb = handle_satn;
389         return;
390     }
391     esp_set_pdma_cb(s, SATN_PDMA_CB);
392     if (esp_select(s) < 0) {
393         return;
394     }
395     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
396     if (cmdlen > 0) {
397         s->cmdfifo_cdb_offset = 1;
398         s->do_cmd = 0;
399         do_cmd(s);
400     } else if (cmdlen == 0) {
401         if (s->dma) {
402             esp_raise_drq(s);
403         }
404         s->do_cmd = 1;
405         /* Target present, but no cmd yet - switch to command phase */
406         s->rregs[ESP_RSEQ] = SEQ_CD;
407         esp_set_phase(s, STAT_CD);
408     }
409 }
410 
411 static void s_without_satn_pdma_cb(ESPState *s)
412 {
413     uint8_t buf[ESP_FIFO_SZ];
414     int n;
415 
416     /* Copy FIFO into cmdfifo */
417     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
418     n = MIN(fifo8_num_free(&s->cmdfifo), n);
419     fifo8_push_all(&s->cmdfifo, buf, n);
420 
421     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
422         s->cmdfifo_cdb_offset = 0;
423         s->do_cmd = 0;
424         do_cmd(s);
425     }
426 }
427 
428 static void handle_s_without_atn(ESPState *s)
429 {
430     int32_t cmdlen;
431 
432     if (s->dma && !s->dma_enabled) {
433         s->dma_cb = handle_s_without_atn;
434         return;
435     }
436     esp_set_pdma_cb(s, S_WITHOUT_SATN_PDMA_CB);
437     if (esp_select(s) < 0) {
438         return;
439     }
440     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
441     if (cmdlen > 0) {
442         s->cmdfifo_cdb_offset = 0;
443         s->do_cmd = 0;
444         do_cmd(s);
445     } else if (cmdlen == 0) {
446         if (s->dma) {
447             esp_raise_drq(s);
448         }
449         s->do_cmd = 1;
450         /* Target present, but no cmd yet - switch to command phase */
451         s->rregs[ESP_RSEQ] = SEQ_CD;
452         esp_set_phase(s, STAT_CD);
453     }
454 }
455 
456 static void satn_stop_pdma_cb(ESPState *s)
457 {
458     uint8_t buf[ESP_FIFO_SZ];
459     int n;
460 
461     /* Copy FIFO into cmdfifo */
462     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
463     n = MIN(fifo8_num_free(&s->cmdfifo), n);
464     fifo8_push_all(&s->cmdfifo, buf, n);
465 
466     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
467         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
468         s->do_cmd = 1;
469         s->cmdfifo_cdb_offset = 1;
470         esp_set_phase(s, STAT_CD);
471         s->rregs[ESP_RSTAT] |= STAT_TC;
472         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
473         s->rregs[ESP_RSEQ] = SEQ_CD;
474         esp_raise_irq(s);
475     }
476 }
477 
478 static void handle_satn_stop(ESPState *s)
479 {
480     int32_t cmdlen;
481 
482     if (s->dma && !s->dma_enabled) {
483         s->dma_cb = handle_satn_stop;
484         return;
485     }
486     esp_set_pdma_cb(s, SATN_STOP_PDMA_CB);
487     if (esp_select(s) < 0) {
488         return;
489     }
490     cmdlen = get_cmd(s, 1);
491     if (cmdlen > 0) {
492         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
493         s->do_cmd = 1;
494         s->cmdfifo_cdb_offset = 1;
495         esp_set_phase(s, STAT_MO);
496         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
497         s->rregs[ESP_RSEQ] = SEQ_MO;
498         esp_raise_irq(s);
499     } else if (cmdlen == 0) {
500         if (s->dma) {
501             esp_raise_drq(s);
502         }
503         s->do_cmd = 1;
504         /* Target present, switch to message out phase */
505         s->rregs[ESP_RSEQ] = SEQ_MO;
506         esp_set_phase(s, STAT_MO);
507     }
508 }
509 
510 static void write_response_pdma_cb(ESPState *s)
511 {
512     esp_set_phase(s, STAT_ST);
513     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
514     s->rregs[ESP_RSEQ] = SEQ_CD;
515     esp_raise_irq(s);
516 }
517 
518 static void write_response(ESPState *s)
519 {
520     uint8_t buf[2];
521 
522     trace_esp_write_response(s->status);
523 
524     buf[0] = s->status;
525     buf[1] = 0;
526 
527     if (s->dma) {
528         if (s->dma_memory_write) {
529             s->dma_memory_write(s->dma_opaque, buf, 2);
530             esp_set_phase(s, STAT_ST);
531             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
532             s->rregs[ESP_RSEQ] = SEQ_CD;
533         } else {
534             esp_set_pdma_cb(s, WRITE_RESPONSE_PDMA_CB);
535             esp_raise_drq(s);
536             return;
537         }
538     } else {
539         fifo8_reset(&s->fifo);
540         fifo8_push_all(&s->fifo, buf, 2);
541         s->rregs[ESP_RFLAGS] = 2;
542     }
543     esp_raise_irq(s);
544 }
545 
546 static void esp_dma_done(ESPState *s)
547 {
548     s->rregs[ESP_RINTR] |= INTR_BS;
549     s->rregs[ESP_RFLAGS] = 0;
550     esp_raise_irq(s);
551 }
552 
553 static void do_dma_pdma_cb(ESPState *s)
554 {
555     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
556     uint8_t buf[ESP_CMDFIFO_SZ];
557     int len;
558     uint32_t n;
559 
560     if (s->do_cmd) {
561         /* Copy FIFO into cmdfifo */
562         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
563         n = MIN(fifo8_num_free(&s->cmdfifo), n);
564         fifo8_push_all(&s->cmdfifo, buf, n);
565 
566         /* Ensure we have received complete command after SATN and stop */
567         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
568             return;
569         }
570 
571         s->ti_size = 0;
572         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
573             /* No command received */
574             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
575                 return;
576             }
577 
578             /* Command has been received */
579             s->do_cmd = 0;
580             do_cmd(s);
581         } else {
582             /*
583              * Extra message out bytes received: update cmdfifo_cdb_offset
584              * and then switch to command phase
585              */
586             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
587             esp_set_phase(s, STAT_CD);
588             s->rregs[ESP_RSEQ] = SEQ_CD;
589             s->rregs[ESP_RINTR] |= INTR_BS;
590             esp_raise_irq(s);
591         }
592         return;
593     }
594 
595     if (!s->current_req) {
596         return;
597     }
598 
599     if (to_device) {
600         /* Copy FIFO data to device */
601         len = MIN(s->async_len, ESP_FIFO_SZ);
602         len = MIN(len, fifo8_num_used(&s->fifo));
603         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
604         s->async_buf += n;
605         s->async_len -= n;
606         s->ti_size += n;
607 
608         if (n < len) {
609             /* Unaligned accesses can cause FIFO wraparound */
610             len = len - n;
611             n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
612             s->async_buf += n;
613             s->async_len -= n;
614             s->ti_size += n;
615         }
616 
617         if (s->async_len == 0) {
618             scsi_req_continue(s->current_req);
619             return;
620         }
621 
622         if (esp_get_tc(s) == 0) {
623             esp_lower_drq(s);
624             esp_dma_done(s);
625         }
626 
627         return;
628     } else {
629         if (s->async_len == 0) {
630             /* Defer until the scsi layer has completed */
631             scsi_req_continue(s->current_req);
632             s->data_in_ready = false;
633             return;
634         }
635 
636         if (esp_get_tc(s) == 0) {
637             esp_lower_drq(s);
638             esp_dma_done(s);
639         }
640 
641         /* Copy device data to FIFO */
642         len = MIN(s->async_len, esp_get_tc(s));
643         len = MIN(len, fifo8_num_free(&s->fifo));
644         fifo8_push_all(&s->fifo, s->async_buf, len);
645         s->async_buf += len;
646         s->async_len -= len;
647         s->ti_size -= len;
648         esp_set_tc(s, esp_get_tc(s) - len);
649     }
650 }
651 
652 static void esp_do_dma(ESPState *s)
653 {
654     uint32_t len, cmdlen;
655     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
656     uint8_t buf[ESP_CMDFIFO_SZ];
657 
658     len = esp_get_tc(s);
659     if (s->do_cmd) {
660         /*
661          * handle_ti_cmd() case: esp_do_dma() is called only from
662          * handle_ti_cmd() with do_cmd != NULL (see the assert())
663          */
664         cmdlen = fifo8_num_used(&s->cmdfifo);
665         trace_esp_do_dma(cmdlen, len);
666         if (s->dma_memory_read) {
667             len = MIN(len, fifo8_num_free(&s->cmdfifo));
668             s->dma_memory_read(s->dma_opaque, buf, len);
669             fifo8_push_all(&s->cmdfifo, buf, len);
670             esp_set_tc(s, esp_get_tc(s) - len);
671         } else {
672             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
673             esp_raise_drq(s);
674             return;
675         }
676         trace_esp_handle_ti_cmd(cmdlen);
677         s->ti_size = 0;
678         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
679             /* No command received */
680             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
681                 return;
682             }
683 
684             /* Command has been received */
685             s->do_cmd = 0;
686             do_cmd(s);
687         } else {
688             /*
689              * Extra message out bytes received: update cmdfifo_cdb_offset
690              * and then switch to command phase
691              */
692             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
693             esp_set_phase(s, STAT_CD);
694             s->rregs[ESP_RSEQ] = SEQ_CD;
695             s->rregs[ESP_RINTR] |= INTR_BS;
696             esp_raise_irq(s);
697         }
698         return;
699     }
700     if (!s->current_req) {
701         return;
702     }
703     if (s->async_len == 0) {
704         /* Defer until data is available.  */
705         return;
706     }
707     if (len > s->async_len) {
708         len = s->async_len;
709     }
710     if (to_device) {
711         if (s->dma_memory_read) {
712             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
713 
714             esp_set_tc(s, esp_get_tc(s) - len);
715             s->async_buf += len;
716             s->async_len -= len;
717             s->ti_size += len;
718 
719             if (s->async_len == 0) {
720                 scsi_req_continue(s->current_req);
721                 /*
722                  * If there is still data to be read from the device then
723                  * complete the DMA operation immediately.  Otherwise defer
724                  * until the scsi layer has completed.
725                  */
726                 return;
727             }
728 
729             /* Partially filled a scsi buffer. Complete immediately.  */
730             esp_dma_done(s);
731             esp_lower_drq(s);
732         } else {
733             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
734             esp_raise_drq(s);
735         }
736     } else {
737         if (s->dma_memory_write) {
738             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
739 
740             esp_set_tc(s, esp_get_tc(s) - len);
741             s->async_buf += len;
742             s->async_len -= len;
743             s->ti_size -= len;
744 
745             if (s->async_len == 0) {
746                 scsi_req_continue(s->current_req);
747                 /*
748                  * If there is still data to be read from the device then
749                  * complete the DMA operation immediately.  Otherwise defer
750                  * until the scsi layer has completed.
751                  */
752                 if (esp_get_tc(s) != 0 || s->ti_size == 0) {
753                     return;
754                 }
755             }
756 
757             /* Partially filled a scsi buffer. Complete immediately.  */
758             esp_dma_done(s);
759             esp_lower_drq(s);
760         } else {
761             /* Adjust TC for any leftover data in the FIFO */
762             if (!fifo8_is_empty(&s->fifo)) {
763                 esp_set_tc(s, esp_get_tc(s) - fifo8_num_used(&s->fifo));
764             }
765 
766             /* Copy device data to FIFO */
767             len = MIN(len, fifo8_num_free(&s->fifo));
768             fifo8_push_all(&s->fifo, s->async_buf, len);
769             s->async_buf += len;
770             s->async_len -= len;
771             s->ti_size -= len;
772             esp_set_tc(s, esp_get_tc(s) - len);
773             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
774             esp_raise_drq(s);
775         }
776     }
777 }
778 
779 static void esp_do_nodma(ESPState *s)
780 {
781     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
782     uint8_t buf[ESP_FIFO_SZ];
783     uint32_t cmdlen;
784     int len, n;
785 
786     if (s->do_cmd) {
787         /* Copy FIFO into cmdfifo */
788         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
789         n = MIN(fifo8_num_free(&s->cmdfifo), n);
790         fifo8_push_all(&s->cmdfifo, buf, n);
791 
792         cmdlen = fifo8_num_used(&s->cmdfifo);
793         trace_esp_handle_ti_cmd(cmdlen);
794         s->ti_size = 0;
795         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
796             /* No command received */
797             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
798                 return;
799             }
800 
801             /* Command has been received */
802             s->do_cmd = 0;
803             do_cmd(s);
804         } else {
805             /*
806              * Extra message out bytes received: update cmdfifo_cdb_offset
807              * and then switch to command phase
808              */
809             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
810             esp_set_phase(s, STAT_CD);
811             s->rregs[ESP_RSEQ] = SEQ_CD;
812             s->rregs[ESP_RINTR] |= INTR_BS;
813             esp_raise_irq(s);
814         }
815         return;
816     }
817 
818     if (!s->current_req) {
819         return;
820     }
821 
822     if (s->async_len == 0) {
823         /* Defer until data is available.  */
824         return;
825     }
826 
827     if (to_device) {
828         len = MIN(s->async_len, ESP_FIFO_SZ);
829         len = MIN(len, fifo8_num_used(&s->fifo));
830         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
831         s->async_buf += len;
832         s->async_len -= len;
833         s->ti_size += len;
834     } else {
835         if (fifo8_is_empty(&s->fifo)) {
836             fifo8_push(&s->fifo, s->async_buf[0]);
837             s->async_buf++;
838             s->async_len--;
839             s->ti_size--;
840         }
841     }
842 
843     if (s->async_len == 0) {
844         scsi_req_continue(s->current_req);
845         return;
846     }
847 
848     s->rregs[ESP_RINTR] |= INTR_BS;
849     esp_raise_irq(s);
850 }
851 
852 static void esp_pdma_cb(ESPState *s)
853 {
854     switch (s->pdma_cb) {
855     case SATN_PDMA_CB:
856         satn_pdma_cb(s);
857         break;
858     case S_WITHOUT_SATN_PDMA_CB:
859         s_without_satn_pdma_cb(s);
860         break;
861     case SATN_STOP_PDMA_CB:
862         satn_stop_pdma_cb(s);
863         break;
864     case WRITE_RESPONSE_PDMA_CB:
865         write_response_pdma_cb(s);
866         break;
867     case DO_DMA_PDMA_CB:
868         do_dma_pdma_cb(s);
869         break;
870     default:
871         g_assert_not_reached();
872     }
873 }
874 
875 void esp_command_complete(SCSIRequest *req, size_t resid)
876 {
877     ESPState *s = req->hba_private;
878     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
879 
880     trace_esp_command_complete();
881 
882     /*
883      * Non-DMA transfers from the target will leave the last byte in
884      * the FIFO so don't reset ti_size in this case
885      */
886     if (s->dma || to_device) {
887         if (s->ti_size != 0) {
888             trace_esp_command_complete_unexpected();
889         }
890         s->ti_size = 0;
891     }
892 
893     s->async_len = 0;
894     if (req->status) {
895         trace_esp_command_complete_fail();
896     }
897     s->status = req->status;
898 
899     /*
900      * If the transfer is finished, switch to status phase. For non-DMA
901      * transfers from the target the last byte is still in the FIFO
902      */
903     if (s->ti_size == 0) {
904         esp_set_phase(s, STAT_ST);
905         esp_dma_done(s);
906         esp_lower_drq(s);
907     }
908 
909     if (s->current_req) {
910         scsi_req_unref(s->current_req);
911         s->current_req = NULL;
912         s->current_dev = NULL;
913     }
914 }
915 
916 void esp_transfer_data(SCSIRequest *req, uint32_t len)
917 {
918     ESPState *s = req->hba_private;
919     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
920     uint32_t dmalen = esp_get_tc(s);
921 
922     assert(!s->do_cmd);
923     trace_esp_transfer_data(dmalen, s->ti_size);
924     s->async_len = len;
925     s->async_buf = scsi_req_get_buf(req);
926 
927     if (!to_device && !s->data_in_ready) {
928         /*
929          * Initial incoming data xfer is complete so raise command
930          * completion interrupt
931          */
932         s->data_in_ready = true;
933         s->rregs[ESP_RINTR] |= INTR_BS;
934         esp_raise_irq(s);
935     }
936 
937     if (s->ti_cmd == 0) {
938         /*
939          * Always perform the initial transfer upon reception of the next TI
940          * command to ensure the DMA/non-DMA status of the command is correct.
941          * It is not possible to use s->dma directly in the section below as
942          * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
943          * async data transfer is delayed then s->dma is set incorrectly.
944          */
945         return;
946     }
947 
948     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
949         if (dmalen) {
950             esp_do_dma(s);
951         } else if (s->ti_size <= 0) {
952             /*
953              * If this was the last part of a DMA transfer then the
954              * completion interrupt is deferred to here.
955              */
956             esp_dma_done(s);
957             esp_lower_drq(s);
958         }
959     } else if (s->ti_cmd == CMD_TI) {
960         esp_do_nodma(s);
961     }
962 }
963 
964 static void handle_ti(ESPState *s)
965 {
966     uint32_t dmalen;
967 
968     if (s->dma && !s->dma_enabled) {
969         s->dma_cb = handle_ti;
970         return;
971     }
972 
973     s->ti_cmd = s->rregs[ESP_CMD];
974     if (s->dma) {
975         dmalen = esp_get_tc(s);
976         trace_esp_handle_ti(dmalen);
977         esp_do_dma(s);
978     } else {
979         trace_esp_handle_ti(s->ti_size);
980         esp_do_nodma(s);
981     }
982 }
983 
984 void esp_hard_reset(ESPState *s)
985 {
986     memset(s->rregs, 0, ESP_REGS);
987     memset(s->wregs, 0, ESP_REGS);
988     s->tchi_written = 0;
989     s->ti_size = 0;
990     s->async_len = 0;
991     fifo8_reset(&s->fifo);
992     fifo8_reset(&s->cmdfifo);
993     s->dma = 0;
994     s->do_cmd = 0;
995     s->dma_cb = NULL;
996 
997     s->rregs[ESP_CFG1] = 7;
998 }
999 
1000 static void esp_soft_reset(ESPState *s)
1001 {
1002     qemu_irq_lower(s->irq);
1003     qemu_irq_lower(s->irq_data);
1004     esp_hard_reset(s);
1005 }
1006 
1007 static void esp_bus_reset(ESPState *s)
1008 {
1009     bus_cold_reset(BUS(&s->bus));
1010 }
1011 
1012 static void parent_esp_reset(ESPState *s, int irq, int level)
1013 {
1014     if (level) {
1015         esp_soft_reset(s);
1016     }
1017 }
1018 
1019 static void esp_run_cmd(ESPState *s)
1020 {
1021     uint8_t cmd = s->rregs[ESP_CMD];
1022 
1023     if (cmd & CMD_DMA) {
1024         s->dma = 1;
1025         /* Reload DMA counter.  */
1026         if (esp_get_stc(s) == 0) {
1027             esp_set_tc(s, 0x10000);
1028         } else {
1029             esp_set_tc(s, esp_get_stc(s));
1030         }
1031     } else {
1032         s->dma = 0;
1033     }
1034     switch (cmd & CMD_CMD) {
1035     case CMD_NOP:
1036         trace_esp_mem_writeb_cmd_nop(cmd);
1037         break;
1038     case CMD_FLUSH:
1039         trace_esp_mem_writeb_cmd_flush(cmd);
1040         fifo8_reset(&s->fifo);
1041         break;
1042     case CMD_RESET:
1043         trace_esp_mem_writeb_cmd_reset(cmd);
1044         esp_soft_reset(s);
1045         break;
1046     case CMD_BUSRESET:
1047         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1048         esp_bus_reset(s);
1049         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1050             s->rregs[ESP_RINTR] |= INTR_RST;
1051             esp_raise_irq(s);
1052         }
1053         break;
1054     case CMD_TI:
1055         trace_esp_mem_writeb_cmd_ti(cmd);
1056         handle_ti(s);
1057         break;
1058     case CMD_ICCS:
1059         trace_esp_mem_writeb_cmd_iccs(cmd);
1060         write_response(s);
1061         s->rregs[ESP_RINTR] |= INTR_FC;
1062         esp_set_phase(s, STAT_MI);
1063         break;
1064     case CMD_MSGACC:
1065         trace_esp_mem_writeb_cmd_msgacc(cmd);
1066         s->rregs[ESP_RINTR] |= INTR_DC;
1067         s->rregs[ESP_RSEQ] = 0;
1068         s->rregs[ESP_RFLAGS] = 0;
1069         esp_raise_irq(s);
1070         break;
1071     case CMD_PAD:
1072         trace_esp_mem_writeb_cmd_pad(cmd);
1073         s->rregs[ESP_RSTAT] = STAT_TC;
1074         s->rregs[ESP_RINTR] |= INTR_FC;
1075         s->rregs[ESP_RSEQ] = 0;
1076         break;
1077     case CMD_SATN:
1078         trace_esp_mem_writeb_cmd_satn(cmd);
1079         break;
1080     case CMD_RSTATN:
1081         trace_esp_mem_writeb_cmd_rstatn(cmd);
1082         break;
1083     case CMD_SEL:
1084         trace_esp_mem_writeb_cmd_sel(cmd);
1085         handle_s_without_atn(s);
1086         break;
1087     case CMD_SELATN:
1088         trace_esp_mem_writeb_cmd_selatn(cmd);
1089         handle_satn(s);
1090         break;
1091     case CMD_SELATNS:
1092         trace_esp_mem_writeb_cmd_selatns(cmd);
1093         handle_satn_stop(s);
1094         break;
1095     case CMD_ENSEL:
1096         trace_esp_mem_writeb_cmd_ensel(cmd);
1097         s->rregs[ESP_RINTR] = 0;
1098         break;
1099     case CMD_DISSEL:
1100         trace_esp_mem_writeb_cmd_dissel(cmd);
1101         s->rregs[ESP_RINTR] = 0;
1102         esp_raise_irq(s);
1103         break;
1104     default:
1105         trace_esp_error_unhandled_command(cmd);
1106         break;
1107     }
1108 }
1109 
1110 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1111 {
1112     uint32_t val;
1113 
1114     switch (saddr) {
1115     case ESP_FIFO:
1116         if (s->dma_memory_read && s->dma_memory_write &&
1117                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1118             /* Data out.  */
1119             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1120             s->rregs[ESP_FIFO] = 0;
1121         } else {
1122             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1123                 if (s->ti_size) {
1124                     esp_do_nodma(s);
1125                 } else {
1126                     /*
1127                      * The last byte of a non-DMA transfer has been read out
1128                      * of the FIFO so switch to status phase
1129                      */
1130                     esp_set_phase(s, STAT_ST);
1131                 }
1132             }
1133             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1134         }
1135         val = s->rregs[ESP_FIFO];
1136         break;
1137     case ESP_RINTR:
1138         /*
1139          * Clear sequence step, interrupt register and all status bits
1140          * except TC
1141          */
1142         val = s->rregs[ESP_RINTR];
1143         s->rregs[ESP_RINTR] = 0;
1144         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1145         /*
1146          * According to the datasheet ESP_RSEQ should be cleared, but as the
1147          * emulation currently defers information transfers to the next TI
1148          * command leave it for now so that pedantic guests such as the old
1149          * Linux 2.6 driver see the correct flags before the next SCSI phase
1150          * transition.
1151          *
1152          * s->rregs[ESP_RSEQ] = SEQ_0;
1153          */
1154         esp_lower_irq(s);
1155         break;
1156     case ESP_TCHI:
1157         /* Return the unique id if the value has never been written */
1158         if (!s->tchi_written) {
1159             val = s->chip_id;
1160         } else {
1161             val = s->rregs[saddr];
1162         }
1163         break;
1164      case ESP_RFLAGS:
1165         /* Bottom 5 bits indicate number of bytes in FIFO */
1166         val = fifo8_num_used(&s->fifo);
1167         break;
1168     default:
1169         val = s->rregs[saddr];
1170         break;
1171     }
1172 
1173     trace_esp_mem_readb(saddr, val);
1174     return val;
1175 }
1176 
1177 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1178 {
1179     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1180     switch (saddr) {
1181     case ESP_TCHI:
1182         s->tchi_written = true;
1183         /* fall through */
1184     case ESP_TCLO:
1185     case ESP_TCMID:
1186         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1187         break;
1188     case ESP_FIFO:
1189         if (s->do_cmd) {
1190             if (!fifo8_is_full(&s->fifo)) {
1191                 esp_fifo_push(&s->fifo, val);
1192                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1193             }
1194 
1195             /*
1196              * If any unexpected message out/command phase data is
1197              * transferred using non-DMA, raise the interrupt
1198              */
1199             if (s->rregs[ESP_CMD] == CMD_TI) {
1200                 s->rregs[ESP_RINTR] |= INTR_BS;
1201                 esp_raise_irq(s);
1202             }
1203         } else {
1204             esp_fifo_push(&s->fifo, val);
1205         }
1206         break;
1207     case ESP_CMD:
1208         s->rregs[saddr] = val;
1209         esp_run_cmd(s);
1210         break;
1211     case ESP_WBUSID ... ESP_WSYNO:
1212         break;
1213     case ESP_CFG1:
1214     case ESP_CFG2: case ESP_CFG3:
1215     case ESP_RES3: case ESP_RES4:
1216         s->rregs[saddr] = val;
1217         break;
1218     case ESP_WCCF ... ESP_WTEST:
1219         break;
1220     default:
1221         trace_esp_error_invalid_write(val, saddr);
1222         return;
1223     }
1224     s->wregs[saddr] = val;
1225 }
1226 
1227 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1228                             unsigned size, bool is_write,
1229                             MemTxAttrs attrs)
1230 {
1231     return (size == 1) || (is_write && size == 4);
1232 }
1233 
1234 static bool esp_is_before_version_5(void *opaque, int version_id)
1235 {
1236     ESPState *s = ESP(opaque);
1237 
1238     version_id = MIN(version_id, s->mig_version_id);
1239     return version_id < 5;
1240 }
1241 
1242 static bool esp_is_version_5(void *opaque, int version_id)
1243 {
1244     ESPState *s = ESP(opaque);
1245 
1246     version_id = MIN(version_id, s->mig_version_id);
1247     return version_id >= 5;
1248 }
1249 
1250 static bool esp_is_version_6(void *opaque, int version_id)
1251 {
1252     ESPState *s = ESP(opaque);
1253 
1254     version_id = MIN(version_id, s->mig_version_id);
1255     return version_id >= 6;
1256 }
1257 
1258 int esp_pre_save(void *opaque)
1259 {
1260     ESPState *s = ESP(object_resolve_path_component(
1261                       OBJECT(opaque), "esp"));
1262 
1263     s->mig_version_id = vmstate_esp.version_id;
1264     return 0;
1265 }
1266 
1267 static int esp_post_load(void *opaque, int version_id)
1268 {
1269     ESPState *s = ESP(opaque);
1270     int len, i;
1271 
1272     version_id = MIN(version_id, s->mig_version_id);
1273 
1274     if (version_id < 5) {
1275         esp_set_tc(s, s->mig_dma_left);
1276 
1277         /* Migrate ti_buf to fifo */
1278         len = s->mig_ti_wptr - s->mig_ti_rptr;
1279         for (i = 0; i < len; i++) {
1280             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1281         }
1282 
1283         /* Migrate cmdbuf to cmdfifo */
1284         for (i = 0; i < s->mig_cmdlen; i++) {
1285             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1286         }
1287     }
1288 
1289     s->mig_version_id = vmstate_esp.version_id;
1290     return 0;
1291 }
1292 
1293 /*
1294  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1295  * guest CPU to perform the transfers between the SCSI bus and memory
1296  * itself. This is indicated by the dma_memory_read and dma_memory_write
1297  * functions being NULL (in contrast to the ESP PCI device) whilst
1298  * dma_enabled is still set.
1299  */
1300 
1301 static bool esp_pdma_needed(void *opaque)
1302 {
1303     ESPState *s = ESP(opaque);
1304 
1305     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1306            s->dma_enabled;
1307 }
1308 
1309 static const VMStateDescription vmstate_esp_pdma = {
1310     .name = "esp/pdma",
1311     .version_id = 0,
1312     .minimum_version_id = 0,
1313     .needed = esp_pdma_needed,
1314     .fields = (const VMStateField[]) {
1315         VMSTATE_UINT8(pdma_cb, ESPState),
1316         VMSTATE_END_OF_LIST()
1317     }
1318 };
1319 
1320 const VMStateDescription vmstate_esp = {
1321     .name = "esp",
1322     .version_id = 6,
1323     .minimum_version_id = 3,
1324     .post_load = esp_post_load,
1325     .fields = (const VMStateField[]) {
1326         VMSTATE_BUFFER(rregs, ESPState),
1327         VMSTATE_BUFFER(wregs, ESPState),
1328         VMSTATE_INT32(ti_size, ESPState),
1329         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1330         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1331         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1332         VMSTATE_UINT32(status, ESPState),
1333         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1334                             esp_is_before_version_5),
1335         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1336                           esp_is_before_version_5),
1337         VMSTATE_UINT32(dma, ESPState),
1338         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1339                               esp_is_before_version_5, 0, 16),
1340         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1341                               esp_is_before_version_5, 16,
1342                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1343         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1344         VMSTATE_UINT32(do_cmd, ESPState),
1345         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1346         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1347         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1348         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1349         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1350         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1351         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1352         VMSTATE_END_OF_LIST()
1353     },
1354     .subsections = (const VMStateDescription * const []) {
1355         &vmstate_esp_pdma,
1356         NULL
1357     }
1358 };
1359 
1360 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1361                                  uint64_t val, unsigned int size)
1362 {
1363     SysBusESPState *sysbus = opaque;
1364     ESPState *s = ESP(&sysbus->esp);
1365     uint32_t saddr;
1366 
1367     saddr = addr >> sysbus->it_shift;
1368     esp_reg_write(s, saddr, val);
1369 }
1370 
1371 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1372                                     unsigned int size)
1373 {
1374     SysBusESPState *sysbus = opaque;
1375     ESPState *s = ESP(&sysbus->esp);
1376     uint32_t saddr;
1377 
1378     saddr = addr >> sysbus->it_shift;
1379     return esp_reg_read(s, saddr);
1380 }
1381 
1382 static const MemoryRegionOps sysbus_esp_mem_ops = {
1383     .read = sysbus_esp_mem_read,
1384     .write = sysbus_esp_mem_write,
1385     .endianness = DEVICE_NATIVE_ENDIAN,
1386     .valid.accepts = esp_mem_accepts,
1387 };
1388 
1389 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1390                                   uint64_t val, unsigned int size)
1391 {
1392     SysBusESPState *sysbus = opaque;
1393     ESPState *s = ESP(&sysbus->esp);
1394 
1395     trace_esp_pdma_write(size);
1396 
1397     switch (size) {
1398     case 1:
1399         esp_pdma_write(s, val);
1400         break;
1401     case 2:
1402         esp_pdma_write(s, val >> 8);
1403         esp_pdma_write(s, val);
1404         break;
1405     }
1406     esp_pdma_cb(s);
1407 }
1408 
1409 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1410                                      unsigned int size)
1411 {
1412     SysBusESPState *sysbus = opaque;
1413     ESPState *s = ESP(&sysbus->esp);
1414     uint64_t val = 0;
1415 
1416     trace_esp_pdma_read(size);
1417 
1418     switch (size) {
1419     case 1:
1420         val = esp_pdma_read(s);
1421         break;
1422     case 2:
1423         val = esp_pdma_read(s);
1424         val = (val << 8) | esp_pdma_read(s);
1425         break;
1426     }
1427     if (fifo8_num_used(&s->fifo) < 2) {
1428         esp_pdma_cb(s);
1429     }
1430     return val;
1431 }
1432 
1433 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1434 {
1435     ESPState *s = container_of(req->bus, ESPState, bus);
1436 
1437     scsi_req_ref(req);
1438     s->current_req = req;
1439     return s;
1440 }
1441 
1442 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1443     .read = sysbus_esp_pdma_read,
1444     .write = sysbus_esp_pdma_write,
1445     .endianness = DEVICE_NATIVE_ENDIAN,
1446     .valid.min_access_size = 1,
1447     .valid.max_access_size = 4,
1448     .impl.min_access_size = 1,
1449     .impl.max_access_size = 2,
1450 };
1451 
1452 static const struct SCSIBusInfo esp_scsi_info = {
1453     .tcq = false,
1454     .max_target = ESP_MAX_DEVS,
1455     .max_lun = 7,
1456 
1457     .load_request = esp_load_request,
1458     .transfer_data = esp_transfer_data,
1459     .complete = esp_command_complete,
1460     .cancel = esp_request_cancelled
1461 };
1462 
1463 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1464 {
1465     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1466     ESPState *s = ESP(&sysbus->esp);
1467 
1468     switch (irq) {
1469     case 0:
1470         parent_esp_reset(s, irq, level);
1471         break;
1472     case 1:
1473         esp_dma_enable(s, irq, level);
1474         break;
1475     }
1476 }
1477 
1478 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1479 {
1480     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1481     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1482     ESPState *s = ESP(&sysbus->esp);
1483 
1484     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1485         return;
1486     }
1487 
1488     sysbus_init_irq(sbd, &s->irq);
1489     sysbus_init_irq(sbd, &s->irq_data);
1490     assert(sysbus->it_shift != -1);
1491 
1492     s->chip_id = TCHI_FAS100A;
1493     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1494                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1495     sysbus_init_mmio(sbd, &sysbus->iomem);
1496     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1497                           sysbus, "esp-pdma", 4);
1498     sysbus_init_mmio(sbd, &sysbus->pdma);
1499 
1500     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1501 
1502     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1503 }
1504 
1505 static void sysbus_esp_hard_reset(DeviceState *dev)
1506 {
1507     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1508     ESPState *s = ESP(&sysbus->esp);
1509 
1510     esp_hard_reset(s);
1511 }
1512 
1513 static void sysbus_esp_init(Object *obj)
1514 {
1515     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1516 
1517     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1518 }
1519 
1520 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1521     .name = "sysbusespscsi",
1522     .version_id = 2,
1523     .minimum_version_id = 1,
1524     .pre_save = esp_pre_save,
1525     .fields = (const VMStateField[]) {
1526         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1527         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1528         VMSTATE_END_OF_LIST()
1529     }
1530 };
1531 
1532 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1533 {
1534     DeviceClass *dc = DEVICE_CLASS(klass);
1535 
1536     dc->realize = sysbus_esp_realize;
1537     dc->reset = sysbus_esp_hard_reset;
1538     dc->vmsd = &vmstate_sysbus_esp_scsi;
1539     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1540 }
1541 
1542 static const TypeInfo sysbus_esp_info = {
1543     .name          = TYPE_SYSBUS_ESP,
1544     .parent        = TYPE_SYS_BUS_DEVICE,
1545     .instance_init = sysbus_esp_init,
1546     .instance_size = sizeof(SysBusESPState),
1547     .class_init    = sysbus_esp_class_init,
1548 };
1549 
1550 static void esp_finalize(Object *obj)
1551 {
1552     ESPState *s = ESP(obj);
1553 
1554     fifo8_destroy(&s->fifo);
1555     fifo8_destroy(&s->cmdfifo);
1556 }
1557 
1558 static void esp_init(Object *obj)
1559 {
1560     ESPState *s = ESP(obj);
1561 
1562     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1563     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1564 }
1565 
1566 static void esp_class_init(ObjectClass *klass, void *data)
1567 {
1568     DeviceClass *dc = DEVICE_CLASS(klass);
1569 
1570     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1571     dc->user_creatable = false;
1572     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1573 }
1574 
1575 static const TypeInfo esp_info = {
1576     .name = TYPE_ESP,
1577     .parent = TYPE_DEVICE,
1578     .instance_init = esp_init,
1579     .instance_finalize = esp_finalize,
1580     .instance_size = sizeof(ESPState),
1581     .class_init = esp_class_init,
1582 };
1583 
1584 static void esp_register_types(void)
1585 {
1586     type_register_static(&sysbus_esp_info);
1587     type_register_static(&esp_info);
1588 }
1589 
1590 type_init(esp_register_types)
1591