xref: /qemu/hw/scsi/esp.c (revision af74b3c15d440d3a3718b8dc6a751c094db75ba3)
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     if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
549         s->rregs[ESP_RINTR] |= INTR_BS;
550         esp_raise_irq(s);
551         esp_lower_drq(s);
552     }
553 }
554 
555 static void do_dma_pdma_cb(ESPState *s)
556 {
557     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
558     uint8_t buf[ESP_CMDFIFO_SZ];
559     int len;
560     uint32_t n;
561 
562     if (s->do_cmd) {
563         /* Copy FIFO into cmdfifo */
564         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
565         n = MIN(fifo8_num_free(&s->cmdfifo), n);
566         fifo8_push_all(&s->cmdfifo, buf, n);
567 
568         /* Ensure we have received complete command after SATN and stop */
569         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
570             return;
571         }
572 
573         s->ti_size = 0;
574         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
575             /* No command received */
576             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
577                 return;
578             }
579 
580             /* Command has been received */
581             s->do_cmd = 0;
582             do_cmd(s);
583         } else {
584             /*
585              * Extra message out bytes received: update cmdfifo_cdb_offset
586              * and then switch to command phase
587              */
588             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
589             esp_set_phase(s, STAT_CD);
590             s->rregs[ESP_RSEQ] = SEQ_CD;
591             s->rregs[ESP_RINTR] |= INTR_BS;
592             esp_raise_irq(s);
593         }
594         return;
595     }
596 
597     if (!s->current_req) {
598         return;
599     }
600 
601     if (to_device) {
602         /* Copy FIFO data to device */
603         len = MIN(s->async_len, ESP_FIFO_SZ);
604         len = MIN(len, fifo8_num_used(&s->fifo));
605         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
606         s->async_buf += n;
607         s->async_len -= n;
608         s->ti_size += n;
609 
610         if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
611             /* Defer until the scsi layer has completed */
612             scsi_req_continue(s->current_req);
613             return;
614         }
615 
616         esp_dma_done(s);
617     } else {
618         if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
619             /* Defer until the scsi layer has completed */
620             scsi_req_continue(s->current_req);
621             s->data_in_ready = false;
622             return;
623         }
624 
625         esp_dma_done(s);
626 
627         /* Copy device data to FIFO */
628         len = MIN(s->async_len, esp_get_tc(s));
629         len = MIN(len, fifo8_num_free(&s->fifo));
630         fifo8_push_all(&s->fifo, s->async_buf, len);
631         s->async_buf += len;
632         s->async_len -= len;
633         s->ti_size -= len;
634         esp_set_tc(s, esp_get_tc(s) - len);
635     }
636 }
637 
638 static void esp_do_dma(ESPState *s)
639 {
640     uint32_t len, cmdlen;
641     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
642     uint8_t buf[ESP_CMDFIFO_SZ];
643 
644     len = esp_get_tc(s);
645     if (s->do_cmd) {
646         /*
647          * handle_ti_cmd() case: esp_do_dma() is called only from
648          * handle_ti_cmd() with do_cmd != NULL (see the assert())
649          */
650         cmdlen = fifo8_num_used(&s->cmdfifo);
651         trace_esp_do_dma(cmdlen, len);
652         if (s->dma_memory_read) {
653             len = MIN(len, fifo8_num_free(&s->cmdfifo));
654             s->dma_memory_read(s->dma_opaque, buf, len);
655             fifo8_push_all(&s->cmdfifo, buf, len);
656             esp_set_tc(s, esp_get_tc(s) - len);
657         } else {
658             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
659             esp_raise_drq(s);
660             return;
661         }
662         trace_esp_handle_ti_cmd(cmdlen);
663         s->ti_size = 0;
664         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
665             /* No command received */
666             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
667                 return;
668             }
669 
670             /* Command has been received */
671             s->do_cmd = 0;
672             do_cmd(s);
673         } else {
674             /*
675              * Extra message out bytes received: update cmdfifo_cdb_offset
676              * and then switch to command phase
677              */
678             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
679             esp_set_phase(s, STAT_CD);
680             s->rregs[ESP_RSEQ] = SEQ_CD;
681             s->rregs[ESP_RINTR] |= INTR_BS;
682             esp_raise_irq(s);
683         }
684         return;
685     }
686     if (!s->current_req) {
687         return;
688     }
689     if (s->async_len == 0) {
690         /* Defer until data is available.  */
691         return;
692     }
693     if (len > s->async_len) {
694         len = s->async_len;
695     }
696     if (to_device) {
697         if (s->dma_memory_read) {
698             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
699 
700             esp_set_tc(s, esp_get_tc(s) - len);
701             s->async_buf += len;
702             s->async_len -= len;
703             s->ti_size += len;
704 
705             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
706                 /* Defer until the scsi layer has completed */
707                 scsi_req_continue(s->current_req);
708                 return;
709             }
710 
711             esp_dma_done(s);
712         } else {
713             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
714             esp_raise_drq(s);
715 
716             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
717                 /* Defer until the scsi layer has completed */
718                 scsi_req_continue(s->current_req);
719                 return;
720             }
721 
722             esp_dma_done(s);
723         }
724     } else {
725         if (s->dma_memory_write) {
726             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
727 
728             esp_set_tc(s, esp_get_tc(s) - len);
729             s->async_buf += len;
730             s->async_len -= len;
731             s->ti_size -= len;
732 
733             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
734                 /* Defer until the scsi layer has completed */
735                 scsi_req_continue(s->current_req);
736                 return;
737             }
738 
739             esp_dma_done(s);
740         } else {
741             /* Copy device data to FIFO */
742             len = MIN(len, fifo8_num_free(&s->fifo));
743             fifo8_push_all(&s->fifo, s->async_buf, len);
744             s->async_buf += len;
745             s->async_len -= len;
746             s->ti_size -= len;
747             esp_set_tc(s, esp_get_tc(s) - len);
748             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
749             esp_raise_drq(s);
750 
751             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
752                 /* Defer until the scsi layer has completed */
753                 scsi_req_continue(s->current_req);
754                 return;
755             }
756 
757             esp_dma_done(s);
758         }
759     }
760 }
761 
762 static void esp_do_nodma(ESPState *s)
763 {
764     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
765     uint8_t buf[ESP_FIFO_SZ];
766     uint32_t cmdlen;
767     int len, n;
768 
769     if (s->do_cmd) {
770         /* Copy FIFO into cmdfifo */
771         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
772         n = MIN(fifo8_num_free(&s->cmdfifo), n);
773         fifo8_push_all(&s->cmdfifo, buf, n);
774 
775         cmdlen = fifo8_num_used(&s->cmdfifo);
776         trace_esp_handle_ti_cmd(cmdlen);
777         s->ti_size = 0;
778         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
779             /* No command received */
780             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
781                 return;
782             }
783 
784             /* Command has been received */
785             s->do_cmd = 0;
786             do_cmd(s);
787         } else {
788             /*
789              * Extra message out bytes received: update cmdfifo_cdb_offset
790              * and then switch to command phase
791              */
792             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
793             esp_set_phase(s, STAT_CD);
794             s->rregs[ESP_RSEQ] = SEQ_CD;
795             s->rregs[ESP_RINTR] |= INTR_BS;
796             esp_raise_irq(s);
797         }
798         return;
799     }
800 
801     if (!s->current_req) {
802         return;
803     }
804 
805     if (s->async_len == 0) {
806         /* Defer until data is available.  */
807         return;
808     }
809 
810     if (to_device) {
811         len = MIN(s->async_len, ESP_FIFO_SZ);
812         len = MIN(len, fifo8_num_used(&s->fifo));
813         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
814         s->async_buf += len;
815         s->async_len -= len;
816         s->ti_size += len;
817     } else {
818         if (fifo8_is_empty(&s->fifo)) {
819             fifo8_push(&s->fifo, s->async_buf[0]);
820             s->async_buf++;
821             s->async_len--;
822             s->ti_size--;
823         }
824     }
825 
826     if (s->async_len == 0) {
827         scsi_req_continue(s->current_req);
828         return;
829     }
830 
831     s->rregs[ESP_RINTR] |= INTR_BS;
832     esp_raise_irq(s);
833 }
834 
835 static void esp_pdma_cb(ESPState *s)
836 {
837     switch (s->pdma_cb) {
838     case SATN_PDMA_CB:
839         satn_pdma_cb(s);
840         break;
841     case S_WITHOUT_SATN_PDMA_CB:
842         s_without_satn_pdma_cb(s);
843         break;
844     case SATN_STOP_PDMA_CB:
845         satn_stop_pdma_cb(s);
846         break;
847     case WRITE_RESPONSE_PDMA_CB:
848         write_response_pdma_cb(s);
849         break;
850     case DO_DMA_PDMA_CB:
851         do_dma_pdma_cb(s);
852         break;
853     default:
854         g_assert_not_reached();
855     }
856 }
857 
858 void esp_command_complete(SCSIRequest *req, size_t resid)
859 {
860     ESPState *s = req->hba_private;
861     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
862 
863     trace_esp_command_complete();
864 
865     /*
866      * Non-DMA transfers from the target will leave the last byte in
867      * the FIFO so don't reset ti_size in this case
868      */
869     if (s->dma || to_device) {
870         if (s->ti_size != 0) {
871             trace_esp_command_complete_unexpected();
872         }
873     }
874 
875     s->async_len = 0;
876     if (req->status) {
877         trace_esp_command_complete_fail();
878     }
879     s->status = req->status;
880 
881     /*
882      * Switch to status phase. For non-DMA transfers from the target the last
883      * byte is still in the FIFO
884      */
885     esp_set_phase(s, STAT_ST);
886     if (s->ti_size == 0) {
887         /*
888          * Transfer complete: force TC to zero just in case a TI command was
889          * requested for more data than the command returns (Solaris 8 does
890          * this)
891          */
892         esp_set_tc(s, 0);
893         esp_dma_done(s);
894     } else {
895         /*
896          * Transfer truncated: raise INTR_BS to indicate early change of
897          * phase
898          */
899         s->rregs[ESP_RINTR] |= INTR_BS;
900         esp_raise_irq(s);
901         s->ti_size = 0;
902     }
903 
904     if (s->current_req) {
905         scsi_req_unref(s->current_req);
906         s->current_req = NULL;
907         s->current_dev = NULL;
908     }
909 }
910 
911 void esp_transfer_data(SCSIRequest *req, uint32_t len)
912 {
913     ESPState *s = req->hba_private;
914     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
915     uint32_t dmalen = esp_get_tc(s);
916 
917     assert(!s->do_cmd);
918     trace_esp_transfer_data(dmalen, s->ti_size);
919     s->async_len = len;
920     s->async_buf = scsi_req_get_buf(req);
921 
922     if (!to_device && !s->data_in_ready) {
923         /*
924          * Initial incoming data xfer is complete so raise command
925          * completion interrupt
926          */
927         s->data_in_ready = true;
928         s->rregs[ESP_RINTR] |= INTR_BS;
929         esp_raise_irq(s);
930     }
931 
932     /*
933      * Always perform the initial transfer upon reception of the next TI
934      * command to ensure the DMA/non-DMA status of the command is correct.
935      * It is not possible to use s->dma directly in the section below as
936      * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
937      * async data transfer is delayed then s->dma is set incorrectly.
938      */
939 
940     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
941         /* When the SCSI layer returns more data, raise deferred INTR_BS */
942         esp_dma_done(s);
943 
944         esp_do_dma(s);
945     } else if (s->ti_cmd == CMD_TI) {
946         esp_do_nodma(s);
947     }
948 }
949 
950 static void handle_ti(ESPState *s)
951 {
952     uint32_t dmalen;
953 
954     if (s->dma && !s->dma_enabled) {
955         s->dma_cb = handle_ti;
956         return;
957     }
958 
959     s->ti_cmd = s->rregs[ESP_CMD];
960     if (s->dma) {
961         dmalen = esp_get_tc(s);
962         trace_esp_handle_ti(dmalen);
963         esp_do_dma(s);
964     } else {
965         trace_esp_handle_ti(s->ti_size);
966         esp_do_nodma(s);
967     }
968 }
969 
970 void esp_hard_reset(ESPState *s)
971 {
972     memset(s->rregs, 0, ESP_REGS);
973     memset(s->wregs, 0, ESP_REGS);
974     s->tchi_written = 0;
975     s->ti_size = 0;
976     s->async_len = 0;
977     fifo8_reset(&s->fifo);
978     fifo8_reset(&s->cmdfifo);
979     s->dma = 0;
980     s->do_cmd = 0;
981     s->dma_cb = NULL;
982 
983     s->rregs[ESP_CFG1] = 7;
984 }
985 
986 static void esp_soft_reset(ESPState *s)
987 {
988     qemu_irq_lower(s->irq);
989     qemu_irq_lower(s->irq_data);
990     esp_hard_reset(s);
991 }
992 
993 static void esp_bus_reset(ESPState *s)
994 {
995     bus_cold_reset(BUS(&s->bus));
996 }
997 
998 static void parent_esp_reset(ESPState *s, int irq, int level)
999 {
1000     if (level) {
1001         esp_soft_reset(s);
1002     }
1003 }
1004 
1005 static void esp_run_cmd(ESPState *s)
1006 {
1007     uint8_t cmd = s->rregs[ESP_CMD];
1008 
1009     if (cmd & CMD_DMA) {
1010         s->dma = 1;
1011         /* Reload DMA counter.  */
1012         if (esp_get_stc(s) == 0) {
1013             esp_set_tc(s, 0x10000);
1014         } else {
1015             esp_set_tc(s, esp_get_stc(s));
1016         }
1017     } else {
1018         s->dma = 0;
1019     }
1020     switch (cmd & CMD_CMD) {
1021     case CMD_NOP:
1022         trace_esp_mem_writeb_cmd_nop(cmd);
1023         break;
1024     case CMD_FLUSH:
1025         trace_esp_mem_writeb_cmd_flush(cmd);
1026         fifo8_reset(&s->fifo);
1027         break;
1028     case CMD_RESET:
1029         trace_esp_mem_writeb_cmd_reset(cmd);
1030         esp_soft_reset(s);
1031         break;
1032     case CMD_BUSRESET:
1033         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1034         esp_bus_reset(s);
1035         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1036             s->rregs[ESP_RINTR] |= INTR_RST;
1037             esp_raise_irq(s);
1038         }
1039         break;
1040     case CMD_TI:
1041         trace_esp_mem_writeb_cmd_ti(cmd);
1042         handle_ti(s);
1043         break;
1044     case CMD_ICCS:
1045         trace_esp_mem_writeb_cmd_iccs(cmd);
1046         write_response(s);
1047         s->rregs[ESP_RINTR] |= INTR_FC;
1048         esp_set_phase(s, STAT_MI);
1049         break;
1050     case CMD_MSGACC:
1051         trace_esp_mem_writeb_cmd_msgacc(cmd);
1052         s->rregs[ESP_RINTR] |= INTR_DC;
1053         s->rregs[ESP_RSEQ] = 0;
1054         s->rregs[ESP_RFLAGS] = 0;
1055         esp_raise_irq(s);
1056         break;
1057     case CMD_PAD:
1058         trace_esp_mem_writeb_cmd_pad(cmd);
1059         s->rregs[ESP_RSTAT] = STAT_TC;
1060         s->rregs[ESP_RINTR] |= INTR_FC;
1061         s->rregs[ESP_RSEQ] = 0;
1062         break;
1063     case CMD_SATN:
1064         trace_esp_mem_writeb_cmd_satn(cmd);
1065         break;
1066     case CMD_RSTATN:
1067         trace_esp_mem_writeb_cmd_rstatn(cmd);
1068         break;
1069     case CMD_SEL:
1070         trace_esp_mem_writeb_cmd_sel(cmd);
1071         handle_s_without_atn(s);
1072         break;
1073     case CMD_SELATN:
1074         trace_esp_mem_writeb_cmd_selatn(cmd);
1075         handle_satn(s);
1076         break;
1077     case CMD_SELATNS:
1078         trace_esp_mem_writeb_cmd_selatns(cmd);
1079         handle_satn_stop(s);
1080         break;
1081     case CMD_ENSEL:
1082         trace_esp_mem_writeb_cmd_ensel(cmd);
1083         s->rregs[ESP_RINTR] = 0;
1084         break;
1085     case CMD_DISSEL:
1086         trace_esp_mem_writeb_cmd_dissel(cmd);
1087         s->rregs[ESP_RINTR] = 0;
1088         esp_raise_irq(s);
1089         break;
1090     default:
1091         trace_esp_error_unhandled_command(cmd);
1092         break;
1093     }
1094 }
1095 
1096 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1097 {
1098     uint32_t val;
1099 
1100     switch (saddr) {
1101     case ESP_FIFO:
1102         if (s->dma_memory_read && s->dma_memory_write &&
1103                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1104             /* Data out.  */
1105             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1106             s->rregs[ESP_FIFO] = 0;
1107         } else {
1108             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1109                 if (s->ti_size) {
1110                     esp_do_nodma(s);
1111                 } else {
1112                     /*
1113                      * The last byte of a non-DMA transfer has been read out
1114                      * of the FIFO so switch to status phase
1115                      */
1116                     esp_set_phase(s, STAT_ST);
1117                 }
1118             }
1119             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1120         }
1121         val = s->rregs[ESP_FIFO];
1122         break;
1123     case ESP_RINTR:
1124         /*
1125          * Clear sequence step, interrupt register and all status bits
1126          * except TC
1127          */
1128         val = s->rregs[ESP_RINTR];
1129         s->rregs[ESP_RINTR] = 0;
1130         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1131         /*
1132          * According to the datasheet ESP_RSEQ should be cleared, but as the
1133          * emulation currently defers information transfers to the next TI
1134          * command leave it for now so that pedantic guests such as the old
1135          * Linux 2.6 driver see the correct flags before the next SCSI phase
1136          * transition.
1137          *
1138          * s->rregs[ESP_RSEQ] = SEQ_0;
1139          */
1140         esp_lower_irq(s);
1141         break;
1142     case ESP_TCHI:
1143         /* Return the unique id if the value has never been written */
1144         if (!s->tchi_written) {
1145             val = s->chip_id;
1146         } else {
1147             val = s->rregs[saddr];
1148         }
1149         break;
1150      case ESP_RFLAGS:
1151         /* Bottom 5 bits indicate number of bytes in FIFO */
1152         val = fifo8_num_used(&s->fifo);
1153         break;
1154     default:
1155         val = s->rregs[saddr];
1156         break;
1157     }
1158 
1159     trace_esp_mem_readb(saddr, val);
1160     return val;
1161 }
1162 
1163 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1164 {
1165     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1166     switch (saddr) {
1167     case ESP_TCHI:
1168         s->tchi_written = true;
1169         /* fall through */
1170     case ESP_TCLO:
1171     case ESP_TCMID:
1172         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1173         break;
1174     case ESP_FIFO:
1175         if (s->do_cmd) {
1176             if (!fifo8_is_full(&s->fifo)) {
1177                 esp_fifo_push(&s->fifo, val);
1178                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1179             }
1180 
1181             /*
1182              * If any unexpected message out/command phase data is
1183              * transferred using non-DMA, raise the interrupt
1184              */
1185             if (s->rregs[ESP_CMD] == CMD_TI) {
1186                 s->rregs[ESP_RINTR] |= INTR_BS;
1187                 esp_raise_irq(s);
1188             }
1189         } else {
1190             esp_fifo_push(&s->fifo, val);
1191         }
1192         break;
1193     case ESP_CMD:
1194         s->rregs[saddr] = val;
1195         esp_run_cmd(s);
1196         break;
1197     case ESP_WBUSID ... ESP_WSYNO:
1198         break;
1199     case ESP_CFG1:
1200     case ESP_CFG2: case ESP_CFG3:
1201     case ESP_RES3: case ESP_RES4:
1202         s->rregs[saddr] = val;
1203         break;
1204     case ESP_WCCF ... ESP_WTEST:
1205         break;
1206     default:
1207         trace_esp_error_invalid_write(val, saddr);
1208         return;
1209     }
1210     s->wregs[saddr] = val;
1211 }
1212 
1213 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1214                             unsigned size, bool is_write,
1215                             MemTxAttrs attrs)
1216 {
1217     return (size == 1) || (is_write && size == 4);
1218 }
1219 
1220 static bool esp_is_before_version_5(void *opaque, int version_id)
1221 {
1222     ESPState *s = ESP(opaque);
1223 
1224     version_id = MIN(version_id, s->mig_version_id);
1225     return version_id < 5;
1226 }
1227 
1228 static bool esp_is_version_5(void *opaque, int version_id)
1229 {
1230     ESPState *s = ESP(opaque);
1231 
1232     version_id = MIN(version_id, s->mig_version_id);
1233     return version_id >= 5;
1234 }
1235 
1236 static bool esp_is_version_6(void *opaque, int version_id)
1237 {
1238     ESPState *s = ESP(opaque);
1239 
1240     version_id = MIN(version_id, s->mig_version_id);
1241     return version_id >= 6;
1242 }
1243 
1244 int esp_pre_save(void *opaque)
1245 {
1246     ESPState *s = ESP(object_resolve_path_component(
1247                       OBJECT(opaque), "esp"));
1248 
1249     s->mig_version_id = vmstate_esp.version_id;
1250     return 0;
1251 }
1252 
1253 static int esp_post_load(void *opaque, int version_id)
1254 {
1255     ESPState *s = ESP(opaque);
1256     int len, i;
1257 
1258     version_id = MIN(version_id, s->mig_version_id);
1259 
1260     if (version_id < 5) {
1261         esp_set_tc(s, s->mig_dma_left);
1262 
1263         /* Migrate ti_buf to fifo */
1264         len = s->mig_ti_wptr - s->mig_ti_rptr;
1265         for (i = 0; i < len; i++) {
1266             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1267         }
1268 
1269         /* Migrate cmdbuf to cmdfifo */
1270         for (i = 0; i < s->mig_cmdlen; i++) {
1271             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1272         }
1273     }
1274 
1275     s->mig_version_id = vmstate_esp.version_id;
1276     return 0;
1277 }
1278 
1279 /*
1280  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1281  * guest CPU to perform the transfers between the SCSI bus and memory
1282  * itself. This is indicated by the dma_memory_read and dma_memory_write
1283  * functions being NULL (in contrast to the ESP PCI device) whilst
1284  * dma_enabled is still set.
1285  */
1286 
1287 static bool esp_pdma_needed(void *opaque)
1288 {
1289     ESPState *s = ESP(opaque);
1290 
1291     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1292            s->dma_enabled;
1293 }
1294 
1295 static const VMStateDescription vmstate_esp_pdma = {
1296     .name = "esp/pdma",
1297     .version_id = 0,
1298     .minimum_version_id = 0,
1299     .needed = esp_pdma_needed,
1300     .fields = (const VMStateField[]) {
1301         VMSTATE_UINT8(pdma_cb, ESPState),
1302         VMSTATE_END_OF_LIST()
1303     }
1304 };
1305 
1306 const VMStateDescription vmstate_esp = {
1307     .name = "esp",
1308     .version_id = 6,
1309     .minimum_version_id = 3,
1310     .post_load = esp_post_load,
1311     .fields = (const VMStateField[]) {
1312         VMSTATE_BUFFER(rregs, ESPState),
1313         VMSTATE_BUFFER(wregs, ESPState),
1314         VMSTATE_INT32(ti_size, ESPState),
1315         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1316         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1317         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1318         VMSTATE_UINT32(status, ESPState),
1319         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1320                             esp_is_before_version_5),
1321         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1322                           esp_is_before_version_5),
1323         VMSTATE_UINT32(dma, ESPState),
1324         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1325                               esp_is_before_version_5, 0, 16),
1326         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1327                               esp_is_before_version_5, 16,
1328                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1329         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1330         VMSTATE_UINT32(do_cmd, ESPState),
1331         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1332         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1333         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1334         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1335         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1336         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1337         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1338         VMSTATE_END_OF_LIST()
1339     },
1340     .subsections = (const VMStateDescription * const []) {
1341         &vmstate_esp_pdma,
1342         NULL
1343     }
1344 };
1345 
1346 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1347                                  uint64_t val, unsigned int size)
1348 {
1349     SysBusESPState *sysbus = opaque;
1350     ESPState *s = ESP(&sysbus->esp);
1351     uint32_t saddr;
1352 
1353     saddr = addr >> sysbus->it_shift;
1354     esp_reg_write(s, saddr, val);
1355 }
1356 
1357 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1358                                     unsigned int size)
1359 {
1360     SysBusESPState *sysbus = opaque;
1361     ESPState *s = ESP(&sysbus->esp);
1362     uint32_t saddr;
1363 
1364     saddr = addr >> sysbus->it_shift;
1365     return esp_reg_read(s, saddr);
1366 }
1367 
1368 static const MemoryRegionOps sysbus_esp_mem_ops = {
1369     .read = sysbus_esp_mem_read,
1370     .write = sysbus_esp_mem_write,
1371     .endianness = DEVICE_NATIVE_ENDIAN,
1372     .valid.accepts = esp_mem_accepts,
1373 };
1374 
1375 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1376                                   uint64_t val, unsigned int size)
1377 {
1378     SysBusESPState *sysbus = opaque;
1379     ESPState *s = ESP(&sysbus->esp);
1380 
1381     trace_esp_pdma_write(size);
1382 
1383     switch (size) {
1384     case 1:
1385         esp_pdma_write(s, val);
1386         break;
1387     case 2:
1388         esp_pdma_write(s, val >> 8);
1389         esp_pdma_write(s, val);
1390         break;
1391     }
1392     esp_pdma_cb(s);
1393 }
1394 
1395 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1396                                      unsigned int size)
1397 {
1398     SysBusESPState *sysbus = opaque;
1399     ESPState *s = ESP(&sysbus->esp);
1400     uint64_t val = 0;
1401 
1402     trace_esp_pdma_read(size);
1403 
1404     switch (size) {
1405     case 1:
1406         val = esp_pdma_read(s);
1407         break;
1408     case 2:
1409         val = esp_pdma_read(s);
1410         val = (val << 8) | esp_pdma_read(s);
1411         break;
1412     }
1413     esp_pdma_cb(s);
1414     return val;
1415 }
1416 
1417 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1418 {
1419     ESPState *s = container_of(req->bus, ESPState, bus);
1420 
1421     scsi_req_ref(req);
1422     s->current_req = req;
1423     return s;
1424 }
1425 
1426 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1427     .read = sysbus_esp_pdma_read,
1428     .write = sysbus_esp_pdma_write,
1429     .endianness = DEVICE_NATIVE_ENDIAN,
1430     .valid.min_access_size = 1,
1431     .valid.max_access_size = 4,
1432     .impl.min_access_size = 1,
1433     .impl.max_access_size = 2,
1434 };
1435 
1436 static const struct SCSIBusInfo esp_scsi_info = {
1437     .tcq = false,
1438     .max_target = ESP_MAX_DEVS,
1439     .max_lun = 7,
1440 
1441     .load_request = esp_load_request,
1442     .transfer_data = esp_transfer_data,
1443     .complete = esp_command_complete,
1444     .cancel = esp_request_cancelled
1445 };
1446 
1447 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1448 {
1449     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1450     ESPState *s = ESP(&sysbus->esp);
1451 
1452     switch (irq) {
1453     case 0:
1454         parent_esp_reset(s, irq, level);
1455         break;
1456     case 1:
1457         esp_dma_enable(s, irq, level);
1458         break;
1459     }
1460 }
1461 
1462 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1463 {
1464     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1465     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1466     ESPState *s = ESP(&sysbus->esp);
1467 
1468     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1469         return;
1470     }
1471 
1472     sysbus_init_irq(sbd, &s->irq);
1473     sysbus_init_irq(sbd, &s->irq_data);
1474     assert(sysbus->it_shift != -1);
1475 
1476     s->chip_id = TCHI_FAS100A;
1477     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1478                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1479     sysbus_init_mmio(sbd, &sysbus->iomem);
1480     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1481                           sysbus, "esp-pdma", 4);
1482     sysbus_init_mmio(sbd, &sysbus->pdma);
1483 
1484     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1485 
1486     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1487 }
1488 
1489 static void sysbus_esp_hard_reset(DeviceState *dev)
1490 {
1491     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1492     ESPState *s = ESP(&sysbus->esp);
1493 
1494     esp_hard_reset(s);
1495 }
1496 
1497 static void sysbus_esp_init(Object *obj)
1498 {
1499     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1500 
1501     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1502 }
1503 
1504 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1505     .name = "sysbusespscsi",
1506     .version_id = 2,
1507     .minimum_version_id = 1,
1508     .pre_save = esp_pre_save,
1509     .fields = (const VMStateField[]) {
1510         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1511         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1512         VMSTATE_END_OF_LIST()
1513     }
1514 };
1515 
1516 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1517 {
1518     DeviceClass *dc = DEVICE_CLASS(klass);
1519 
1520     dc->realize = sysbus_esp_realize;
1521     dc->reset = sysbus_esp_hard_reset;
1522     dc->vmsd = &vmstate_sysbus_esp_scsi;
1523     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1524 }
1525 
1526 static const TypeInfo sysbus_esp_info = {
1527     .name          = TYPE_SYSBUS_ESP,
1528     .parent        = TYPE_SYS_BUS_DEVICE,
1529     .instance_init = sysbus_esp_init,
1530     .instance_size = sizeof(SysBusESPState),
1531     .class_init    = sysbus_esp_class_init,
1532 };
1533 
1534 static void esp_finalize(Object *obj)
1535 {
1536     ESPState *s = ESP(obj);
1537 
1538     fifo8_destroy(&s->fifo);
1539     fifo8_destroy(&s->cmdfifo);
1540 }
1541 
1542 static void esp_init(Object *obj)
1543 {
1544     ESPState *s = ESP(obj);
1545 
1546     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1547     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1548 }
1549 
1550 static void esp_class_init(ObjectClass *klass, void *data)
1551 {
1552     DeviceClass *dc = DEVICE_CLASS(klass);
1553 
1554     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1555     dc->user_creatable = false;
1556     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1557 }
1558 
1559 static const TypeInfo esp_info = {
1560     .name = TYPE_ESP,
1561     .parent = TYPE_DEVICE,
1562     .instance_init = esp_init,
1563     .instance_finalize = esp_finalize,
1564     .instance_size = sizeof(ESPState),
1565     .class_init = esp_class_init,
1566 };
1567 
1568 static void esp_register_types(void)
1569 {
1570     type_register_static(&sysbus_esp_info);
1571     type_register_static(&esp_info);
1572 }
1573 
1574 type_init(esp_register_types)
1575