xref: /qemu/hw/scsi/esp.c (revision 2c1017bfc28b792dd03ea2aaa7453ec20ab5f7ec)
1 /*
2  * QEMU ESP/NCR53C9x emulation
3  *
4  * Copyright (c) 2005-2006 Fabrice Bellard
5  * Copyright (c) 2012 Herve Poussineau
6  * Copyright (c) 2023 Mark Cave-Ayland
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #include "qemu/osdep.h"
28 #include "hw/sysbus.h"
29 #include "migration/vmstate.h"
30 #include "hw/irq.h"
31 #include "hw/scsi/esp.h"
32 #include "trace.h"
33 #include "qemu/log.h"
34 #include "qemu/module.h"
35 
36 /*
37  * On Sparc32, this is the ESP (NCR53C90) part of chip STP2000 (Master I/O),
38  * also produced as NCR89C100. See
39  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
40  * and
41  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR53C9X.txt
42  *
43  * On Macintosh Quadra it is a NCR53C96.
44  */
45 
46 static void esp_raise_irq(ESPState *s)
47 {
48     if (!(s->rregs[ESP_RSTAT] & STAT_INT)) {
49         s->rregs[ESP_RSTAT] |= STAT_INT;
50         qemu_irq_raise(s->irq);
51         trace_esp_raise_irq();
52     }
53 }
54 
55 static void esp_lower_irq(ESPState *s)
56 {
57     if (s->rregs[ESP_RSTAT] & STAT_INT) {
58         s->rregs[ESP_RSTAT] &= ~STAT_INT;
59         qemu_irq_lower(s->irq);
60         trace_esp_lower_irq();
61     }
62 }
63 
64 static void esp_raise_drq(ESPState *s)
65 {
66     if (!(s->drq_state)) {
67         qemu_irq_raise(s->drq_irq);
68         trace_esp_raise_drq();
69         s->drq_state = true;
70     }
71 }
72 
73 static void esp_lower_drq(ESPState *s)
74 {
75     if (s->drq_state) {
76         qemu_irq_lower(s->drq_irq);
77         trace_esp_lower_drq();
78         s->drq_state = false;
79     }
80 }
81 
82 static const char *esp_phase_names[8] = {
83     "DATA OUT", "DATA IN", "COMMAND", "STATUS",
84     "(reserved)", "(reserved)", "MESSAGE OUT", "MESSAGE IN"
85 };
86 
87 static void esp_set_phase(ESPState *s, uint8_t phase)
88 {
89     s->rregs[ESP_RSTAT] &= ~7;
90     s->rregs[ESP_RSTAT] |= phase;
91 
92     trace_esp_set_phase(esp_phase_names[phase]);
93 }
94 
95 static uint8_t esp_get_phase(ESPState *s)
96 {
97     return s->rregs[ESP_RSTAT] & 7;
98 }
99 
100 void esp_dma_enable(ESPState *s, int irq, int level)
101 {
102     if (level) {
103         s->dma_enabled = 1;
104         trace_esp_dma_enable();
105         if (s->dma_cb) {
106             s->dma_cb(s);
107             s->dma_cb = NULL;
108         }
109     } else {
110         trace_esp_dma_disable();
111         s->dma_enabled = 0;
112     }
113 }
114 
115 void esp_request_cancelled(SCSIRequest *req)
116 {
117     ESPState *s = req->hba_private;
118 
119     if (req == s->current_req) {
120         scsi_req_unref(s->current_req);
121         s->current_req = NULL;
122         s->current_dev = NULL;
123         s->async_len = 0;
124     }
125 }
126 
127 static void esp_fifo_push(ESPState *s, uint8_t val)
128 {
129     if (fifo8_num_used(&s->fifo) == s->fifo.capacity) {
130         trace_esp_error_fifo_overrun();
131         return;
132     }
133 
134     fifo8_push(&s->fifo, val);
135 }
136 
137 static void esp_fifo_push_buf(ESPState *s, uint8_t *buf, int len)
138 {
139     fifo8_push_all(&s->fifo, buf, len);
140 }
141 
142 static uint8_t esp_fifo_pop(ESPState *s)
143 {
144     if (fifo8_is_empty(&s->fifo)) {
145         return 0;
146     }
147 
148     return fifo8_pop(&s->fifo);
149 }
150 
151 static uint32_t esp_fifo8_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen)
152 {
153     const uint8_t *buf;
154     uint32_t n, n2;
155     int len;
156 
157     if (maxlen == 0) {
158         return 0;
159     }
160 
161     len = maxlen;
162     buf = fifo8_pop_buf(fifo, len, &n);
163     if (dest) {
164         memcpy(dest, buf, n);
165     }
166 
167     /* Add FIFO wraparound if needed */
168     len -= n;
169     len = MIN(len, fifo8_num_used(fifo));
170     if (len) {
171         buf = fifo8_pop_buf(fifo, len, &n2);
172         if (dest) {
173             memcpy(&dest[n], buf, n2);
174         }
175         n += n2;
176     }
177 
178     return n;
179 }
180 
181 static uint32_t esp_fifo_pop_buf(ESPState *s, uint8_t *dest, int maxlen)
182 {
183     return esp_fifo8_pop_buf(&s->fifo, dest, maxlen);
184 }
185 
186 static uint32_t esp_get_tc(ESPState *s)
187 {
188     uint32_t dmalen;
189 
190     dmalen = s->rregs[ESP_TCLO];
191     dmalen |= s->rregs[ESP_TCMID] << 8;
192     dmalen |= s->rregs[ESP_TCHI] << 16;
193 
194     return dmalen;
195 }
196 
197 static void esp_set_tc(ESPState *s, uint32_t dmalen)
198 {
199     uint32_t old_tc = esp_get_tc(s);
200 
201     s->rregs[ESP_TCLO] = dmalen;
202     s->rregs[ESP_TCMID] = dmalen >> 8;
203     s->rregs[ESP_TCHI] = dmalen >> 16;
204 
205     if (old_tc && dmalen == 0) {
206         s->rregs[ESP_RSTAT] |= STAT_TC;
207     }
208 }
209 
210 static uint32_t esp_get_stc(ESPState *s)
211 {
212     uint32_t dmalen;
213 
214     dmalen = s->wregs[ESP_TCLO];
215     dmalen |= s->wregs[ESP_TCMID] << 8;
216     dmalen |= s->wregs[ESP_TCHI] << 16;
217 
218     return dmalen;
219 }
220 
221 static uint8_t esp_pdma_read(ESPState *s)
222 {
223     uint8_t val;
224 
225     val = esp_fifo_pop(s);
226     return val;
227 }
228 
229 static void esp_pdma_write(ESPState *s, uint8_t val)
230 {
231     uint32_t dmalen = esp_get_tc(s);
232 
233     if (dmalen == 0) {
234         return;
235     }
236 
237     esp_fifo_push(s, val);
238 
239     dmalen--;
240     esp_set_tc(s, dmalen);
241 }
242 
243 static int esp_select(ESPState *s)
244 {
245     int target;
246 
247     target = s->wregs[ESP_WBUSID] & BUSID_DID;
248 
249     s->ti_size = 0;
250     s->rregs[ESP_RSEQ] = SEQ_0;
251 
252     if (s->current_req) {
253         /* Started a new command before the old one finished. Cancel it. */
254         scsi_req_cancel(s->current_req);
255     }
256 
257     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
258     if (!s->current_dev) {
259         /* No such drive */
260         s->rregs[ESP_RSTAT] = 0;
261         s->rregs[ESP_RINTR] = INTR_DC;
262         esp_raise_irq(s);
263         return -1;
264     }
265 
266     /*
267      * Note that we deliberately don't raise the IRQ here: this will be done
268      * either in esp_transfer_data() or esp_command_complete()
269      */
270     return 0;
271 }
272 
273 static void esp_do_dma(ESPState *s);
274 static void esp_do_nodma(ESPState *s);
275 
276 static void do_command_phase(ESPState *s)
277 {
278     uint32_t cmdlen;
279     int32_t datalen;
280     SCSIDevice *current_lun;
281     uint8_t buf[ESP_CMDFIFO_SZ];
282 
283     trace_esp_do_command_phase(s->lun);
284     cmdlen = fifo8_num_used(&s->cmdfifo);
285     if (!cmdlen || !s->current_dev) {
286         return;
287     }
288     esp_fifo8_pop_buf(&s->cmdfifo, buf, cmdlen);
289 
290     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
291     if (!current_lun) {
292         /* No such drive */
293         s->rregs[ESP_RSTAT] = 0;
294         s->rregs[ESP_RINTR] = INTR_DC;
295         s->rregs[ESP_RSEQ] = SEQ_0;
296         esp_raise_irq(s);
297         return;
298     }
299 
300     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
301     datalen = scsi_req_enqueue(s->current_req);
302     s->ti_size = datalen;
303     fifo8_reset(&s->cmdfifo);
304     s->data_ready = false;
305     if (datalen != 0) {
306         /*
307          * Switch to DATA phase but wait until initial data xfer is
308          * complete before raising the command completion interrupt
309          */
310         if (datalen > 0) {
311             esp_set_phase(s, STAT_DI);
312         } else {
313             esp_set_phase(s, STAT_DO);
314         }
315         scsi_req_continue(s->current_req);
316         return;
317     }
318 }
319 
320 static void do_message_phase(ESPState *s)
321 {
322     if (s->cmdfifo_cdb_offset) {
323         uint8_t message = fifo8_is_empty(&s->cmdfifo) ? 0 :
324                           fifo8_pop(&s->cmdfifo);
325 
326         trace_esp_do_identify(message);
327         s->lun = message & 7;
328         s->cmdfifo_cdb_offset--;
329     }
330 
331     /* Ignore extended messages for now */
332     if (s->cmdfifo_cdb_offset) {
333         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
334         esp_fifo8_pop_buf(&s->cmdfifo, NULL, len);
335         s->cmdfifo_cdb_offset = 0;
336     }
337 }
338 
339 static void do_cmd(ESPState *s)
340 {
341     do_message_phase(s);
342     assert(s->cmdfifo_cdb_offset == 0);
343     do_command_phase(s);
344 }
345 
346 static void handle_satn(ESPState *s)
347 {
348     if (s->dma && !s->dma_enabled) {
349         s->dma_cb = handle_satn;
350         return;
351     }
352 
353     if (esp_select(s) < 0) {
354         return;
355     }
356 
357     esp_set_phase(s, STAT_MO);
358 
359     if (s->dma) {
360         esp_do_dma(s);
361     } else {
362         esp_do_nodma(s);
363     }
364 }
365 
366 static void handle_s_without_atn(ESPState *s)
367 {
368     if (s->dma && !s->dma_enabled) {
369         s->dma_cb = handle_s_without_atn;
370         return;
371     }
372 
373     if (esp_select(s) < 0) {
374         return;
375     }
376 
377     esp_set_phase(s, STAT_CD);
378     s->cmdfifo_cdb_offset = 0;
379 
380     if (s->dma) {
381         esp_do_dma(s);
382     } else {
383         esp_do_nodma(s);
384     }
385 }
386 
387 static void handle_satn_stop(ESPState *s)
388 {
389     if (s->dma && !s->dma_enabled) {
390         s->dma_cb = handle_satn_stop;
391         return;
392     }
393 
394     if (esp_select(s) < 0) {
395         return;
396     }
397 
398     esp_set_phase(s, STAT_MO);
399     s->cmdfifo_cdb_offset = 0;
400 
401     if (s->dma) {
402         esp_do_dma(s);
403     } else {
404         esp_do_nodma(s);
405     }
406 }
407 
408 static void handle_pad(ESPState *s)
409 {
410     if (s->dma) {
411         esp_do_dma(s);
412     } else {
413         esp_do_nodma(s);
414     }
415 }
416 
417 static void write_response(ESPState *s)
418 {
419     trace_esp_write_response(s->status);
420 
421     if (s->dma) {
422         esp_do_dma(s);
423     } else {
424         esp_do_nodma(s);
425     }
426 }
427 
428 static bool esp_cdb_ready(ESPState *s)
429 {
430     int len = fifo8_num_used(&s->cmdfifo) - s->cmdfifo_cdb_offset;
431     const uint8_t *pbuf;
432     uint32_t n;
433     int cdblen;
434 
435     if (len <= 0) {
436         return false;
437     }
438 
439     pbuf = fifo8_peek_buf(&s->cmdfifo, len, &n);
440     if (n < len) {
441         /*
442          * In normal use the cmdfifo should never wrap, but include this check
443          * to prevent a malicious guest from reading past the end of the
444          * cmdfifo data buffer below
445          */
446         return false;
447     }
448 
449     cdblen = scsi_cdb_length((uint8_t *)&pbuf[s->cmdfifo_cdb_offset]);
450 
451     return cdblen < 0 ? false : (len >= cdblen);
452 }
453 
454 static void esp_dma_ti_check(ESPState *s)
455 {
456     if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
457         s->rregs[ESP_RINTR] |= INTR_BS;
458         esp_raise_irq(s);
459         esp_lower_drq(s);
460     }
461 }
462 
463 static void esp_do_dma(ESPState *s)
464 {
465     uint32_t len, cmdlen;
466     uint8_t buf[ESP_CMDFIFO_SZ];
467 
468     len = esp_get_tc(s);
469 
470     switch (esp_get_phase(s)) {
471     case STAT_MO:
472         if (s->dma_memory_read) {
473             len = MIN(len, fifo8_num_free(&s->cmdfifo));
474             s->dma_memory_read(s->dma_opaque, buf, len);
475             esp_set_tc(s, esp_get_tc(s) - len);
476         } else {
477             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
478             len = MIN(fifo8_num_free(&s->cmdfifo), len);
479             esp_raise_drq(s);
480         }
481 
482         fifo8_push_all(&s->cmdfifo, buf, len);
483         s->cmdfifo_cdb_offset += len;
484 
485         switch (s->rregs[ESP_CMD]) {
486         case CMD_SELATN | CMD_DMA:
487             if (fifo8_num_used(&s->cmdfifo) >= 1) {
488                 /* First byte received, switch to command phase */
489                 esp_set_phase(s, STAT_CD);
490                 s->rregs[ESP_RSEQ] = SEQ_CD;
491                 s->cmdfifo_cdb_offset = 1;
492 
493                 if (fifo8_num_used(&s->cmdfifo) > 1) {
494                     /* Process any additional command phase data */
495                     esp_do_dma(s);
496                 }
497             }
498             break;
499 
500         case CMD_SELATNS | CMD_DMA:
501             if (fifo8_num_used(&s->cmdfifo) == 1) {
502                 /* First byte received, stop in message out phase */
503                 s->rregs[ESP_RSEQ] = SEQ_MO;
504                 s->cmdfifo_cdb_offset = 1;
505 
506                 /* Raise command completion interrupt */
507                 s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
508                 esp_raise_irq(s);
509             }
510             break;
511 
512         case CMD_TI | CMD_DMA:
513             /* ATN remains asserted until TC == 0 */
514             if (esp_get_tc(s) == 0) {
515                 esp_set_phase(s, STAT_CD);
516                 s->rregs[ESP_CMD] = 0;
517                 s->rregs[ESP_RINTR] |= INTR_BS;
518                 esp_raise_irq(s);
519             }
520             break;
521         }
522         break;
523 
524     case STAT_CD:
525         cmdlen = fifo8_num_used(&s->cmdfifo);
526         trace_esp_do_dma(cmdlen, len);
527         if (s->dma_memory_read) {
528             len = MIN(len, fifo8_num_free(&s->cmdfifo));
529             s->dma_memory_read(s->dma_opaque, buf, len);
530             fifo8_push_all(&s->cmdfifo, buf, len);
531             esp_set_tc(s, esp_get_tc(s) - len);
532         } else {
533             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
534             len = MIN(fifo8_num_free(&s->cmdfifo), len);
535             fifo8_push_all(&s->cmdfifo, buf, len);
536             esp_raise_drq(s);
537         }
538         trace_esp_handle_ti_cmd(cmdlen);
539         s->ti_size = 0;
540         if (esp_get_tc(s) == 0) {
541             /* Command has been received */
542             do_cmd(s);
543         }
544         break;
545 
546     case STAT_DO:
547         if (!s->current_req) {
548             return;
549         }
550         if (s->async_len == 0 && esp_get_tc(s) && s->ti_size) {
551             /* Defer until data is available.  */
552             return;
553         }
554         if (len > s->async_len) {
555             len = s->async_len;
556         }
557 
558         switch (s->rregs[ESP_CMD]) {
559         case CMD_TI | CMD_DMA:
560             if (s->dma_memory_read) {
561                 s->dma_memory_read(s->dma_opaque, s->async_buf, len);
562                 esp_set_tc(s, esp_get_tc(s) - len);
563             } else {
564                 /* Copy FIFO data to device */
565                 len = MIN(s->async_len, ESP_FIFO_SZ);
566                 len = MIN(len, fifo8_num_used(&s->fifo));
567                 len = esp_fifo_pop_buf(s, s->async_buf, len);
568                 esp_raise_drq(s);
569             }
570 
571             s->async_buf += len;
572             s->async_len -= len;
573             s->ti_size += len;
574             break;
575 
576         case CMD_PAD | CMD_DMA:
577             /* Copy TC zero bytes into the incoming stream */
578             if (!s->dma_memory_read) {
579                 len = MIN(s->async_len, ESP_FIFO_SZ);
580                 len = MIN(len, fifo8_num_free(&s->fifo));
581             }
582 
583             memset(s->async_buf, 0, len);
584 
585             s->async_buf += len;
586             s->async_len -= len;
587             s->ti_size += len;
588             break;
589         }
590 
591         if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
592             /* Defer until the scsi layer has completed */
593             scsi_req_continue(s->current_req);
594             return;
595         }
596 
597         esp_dma_ti_check(s);
598         break;
599 
600     case STAT_DI:
601         if (!s->current_req) {
602             return;
603         }
604         if (s->async_len == 0 && esp_get_tc(s) && s->ti_size) {
605             /* Defer until data is available.  */
606             return;
607         }
608         if (len > s->async_len) {
609             len = s->async_len;
610         }
611 
612         switch (s->rregs[ESP_CMD]) {
613         case CMD_TI | CMD_DMA:
614             if (s->dma_memory_write) {
615                 s->dma_memory_write(s->dma_opaque, s->async_buf, len);
616             } else {
617                 /* Copy device data to FIFO */
618                 len = MIN(len, fifo8_num_free(&s->fifo));
619                 esp_fifo_push_buf(s, s->async_buf, len);
620                 esp_raise_drq(s);
621             }
622 
623             s->async_buf += len;
624             s->async_len -= len;
625             s->ti_size -= len;
626             esp_set_tc(s, esp_get_tc(s) - len);
627             break;
628 
629         case CMD_PAD | CMD_DMA:
630             /* Drop TC bytes from the incoming stream */
631             if (!s->dma_memory_write) {
632                 len = MIN(len, fifo8_num_free(&s->fifo));
633             }
634 
635             s->async_buf += len;
636             s->async_len -= len;
637             s->ti_size -= len;
638             esp_set_tc(s, esp_get_tc(s) - len);
639             break;
640         }
641 
642         if (s->async_len == 0 && s->ti_size == 0 && esp_get_tc(s)) {
643             /* If the guest underflows TC then terminate SCSI request */
644             scsi_req_continue(s->current_req);
645             return;
646         }
647 
648         if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
649             /* Defer until the scsi layer has completed */
650             scsi_req_continue(s->current_req);
651             return;
652         }
653 
654         esp_dma_ti_check(s);
655         break;
656 
657     case STAT_ST:
658         switch (s->rregs[ESP_CMD]) {
659         case CMD_ICCS | CMD_DMA:
660             len = MIN(len, 1);
661 
662             if (len) {
663                 buf[0] = s->status;
664 
665                 if (s->dma_memory_write) {
666                     s->dma_memory_write(s->dma_opaque, buf, len);
667                 } else {
668                     esp_fifo_push_buf(s, buf, len);
669                 }
670 
671                 esp_set_tc(s, esp_get_tc(s) - len);
672                 esp_set_phase(s, STAT_MI);
673 
674                 if (esp_get_tc(s) > 0) {
675                     /* Process any message in phase data */
676                     esp_do_dma(s);
677                 }
678             }
679             break;
680 
681         default:
682             /* Consume remaining data if the guest underflows TC */
683             if (fifo8_num_used(&s->fifo) < 2) {
684                 s->rregs[ESP_RINTR] |= INTR_BS;
685                 esp_raise_irq(s);
686                 esp_lower_drq(s);
687             }
688             break;
689         }
690         break;
691 
692     case STAT_MI:
693         switch (s->rregs[ESP_CMD]) {
694         case CMD_ICCS | CMD_DMA:
695             len = MIN(len, 1);
696 
697             if (len) {
698                 buf[0] = 0;
699 
700                 if (s->dma_memory_write) {
701                     s->dma_memory_write(s->dma_opaque, buf, len);
702                 } else {
703                     esp_fifo_push_buf(s, buf, len);
704                 }
705 
706                 esp_set_tc(s, esp_get_tc(s) - len);
707 
708                 /* Raise end of command interrupt */
709                 s->rregs[ESP_RINTR] |= INTR_FC;
710                 esp_raise_irq(s);
711             }
712             break;
713         }
714         break;
715     }
716 }
717 
718 static void esp_nodma_ti_dataout(ESPState *s)
719 {
720     int len;
721 
722     if (!s->current_req) {
723         return;
724     }
725     if (s->async_len == 0) {
726         /* Defer until data is available.  */
727         return;
728     }
729     len = MIN(s->async_len, ESP_FIFO_SZ);
730     len = MIN(len, fifo8_num_used(&s->fifo));
731     esp_fifo_pop_buf(s, s->async_buf, len);
732     s->async_buf += len;
733     s->async_len -= len;
734     s->ti_size += len;
735 
736     if (s->async_len == 0) {
737         scsi_req_continue(s->current_req);
738         return;
739     }
740 
741     s->rregs[ESP_RINTR] |= INTR_BS;
742     esp_raise_irq(s);
743 }
744 
745 static void esp_do_nodma(ESPState *s)
746 {
747     uint8_t buf[ESP_FIFO_SZ];
748     uint32_t cmdlen;
749     int len;
750 
751     switch (esp_get_phase(s)) {
752     case STAT_MO:
753         switch (s->rregs[ESP_CMD]) {
754         case CMD_SELATN:
755             /* Copy FIFO into cmdfifo */
756             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
757             len = MIN(fifo8_num_free(&s->cmdfifo), len);
758             fifo8_push_all(&s->cmdfifo, buf, len);
759 
760             if (fifo8_num_used(&s->cmdfifo) >= 1) {
761                 /* First byte received, switch to command phase */
762                 esp_set_phase(s, STAT_CD);
763                 s->rregs[ESP_RSEQ] = SEQ_CD;
764                 s->cmdfifo_cdb_offset = 1;
765 
766                 if (fifo8_num_used(&s->cmdfifo) > 1) {
767                     /* Process any additional command phase data */
768                     esp_do_nodma(s);
769                 }
770             }
771             break;
772 
773         case CMD_SELATNS:
774             /* Copy one byte from FIFO into cmdfifo */
775             len = esp_fifo_pop_buf(s, buf,
776                                    MIN(fifo8_num_used(&s->fifo), 1));
777             len = MIN(fifo8_num_free(&s->cmdfifo), len);
778             fifo8_push_all(&s->cmdfifo, buf, len);
779 
780             if (fifo8_num_used(&s->cmdfifo) >= 1) {
781                 /* First byte received, stop in message out phase */
782                 s->rregs[ESP_RSEQ] = SEQ_MO;
783                 s->cmdfifo_cdb_offset = 1;
784 
785                 /* Raise command completion interrupt */
786                 s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
787                 esp_raise_irq(s);
788             }
789             break;
790 
791         case CMD_TI:
792             /* Copy FIFO into cmdfifo */
793             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
794             len = MIN(fifo8_num_free(&s->cmdfifo), len);
795             fifo8_push_all(&s->cmdfifo, buf, len);
796 
797             /* ATN remains asserted until FIFO empty */
798             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
799             esp_set_phase(s, STAT_CD);
800             s->rregs[ESP_CMD] = 0;
801             s->rregs[ESP_RINTR] |= INTR_BS;
802             esp_raise_irq(s);
803             break;
804         }
805         break;
806 
807     case STAT_CD:
808         switch (s->rregs[ESP_CMD]) {
809         case CMD_TI:
810             /* Copy FIFO into cmdfifo */
811             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
812             len = MIN(fifo8_num_free(&s->cmdfifo), len);
813             fifo8_push_all(&s->cmdfifo, buf, len);
814 
815             cmdlen = fifo8_num_used(&s->cmdfifo);
816             trace_esp_handle_ti_cmd(cmdlen);
817 
818             /* CDB may be transferred in one or more TI commands */
819             if (esp_cdb_ready(s)) {
820                 /* Command has been received */
821                 do_cmd(s);
822             } else {
823                 /*
824                  * If data was transferred from the FIFO then raise bus
825                  * service interrupt to indicate transfer complete. Otherwise
826                  * defer until the next FIFO write.
827                  */
828                 if (len) {
829                     /* Raise interrupt to indicate transfer complete */
830                     s->rregs[ESP_RINTR] |= INTR_BS;
831                     esp_raise_irq(s);
832                 }
833             }
834             break;
835 
836         case CMD_SEL | CMD_DMA:
837         case CMD_SELATN | CMD_DMA:
838             /* Copy FIFO into cmdfifo */
839             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
840             len = MIN(fifo8_num_free(&s->cmdfifo), len);
841             fifo8_push_all(&s->cmdfifo, buf, len);
842 
843             /* Handle when DMA transfer is terminated by non-DMA FIFO write */
844             if (esp_cdb_ready(s)) {
845                 /* Command has been received */
846                 do_cmd(s);
847             }
848             break;
849 
850         case CMD_SEL:
851         case CMD_SELATN:
852             /* FIFO already contain entire CDB: copy to cmdfifo and execute */
853             len = esp_fifo_pop_buf(s, buf, fifo8_num_used(&s->fifo));
854             len = MIN(fifo8_num_free(&s->cmdfifo), len);
855             fifo8_push_all(&s->cmdfifo, buf, len);
856 
857             do_cmd(s);
858             break;
859         }
860         break;
861 
862     case STAT_DO:
863         /* Accumulate data in FIFO until non-DMA TI is executed */
864         break;
865 
866     case STAT_DI:
867         if (!s->current_req) {
868             return;
869         }
870         if (s->async_len == 0) {
871             /* Defer until data is available.  */
872             return;
873         }
874         if (fifo8_is_empty(&s->fifo)) {
875             esp_fifo_push(s, s->async_buf[0]);
876             s->async_buf++;
877             s->async_len--;
878             s->ti_size--;
879         }
880 
881         if (s->async_len == 0) {
882             scsi_req_continue(s->current_req);
883             return;
884         }
885 
886         /* If preloading the FIFO, defer until TI command issued */
887         if (s->rregs[ESP_CMD] != CMD_TI) {
888             return;
889         }
890 
891         s->rregs[ESP_RINTR] |= INTR_BS;
892         esp_raise_irq(s);
893         break;
894 
895     case STAT_ST:
896         switch (s->rregs[ESP_CMD]) {
897         case CMD_ICCS:
898             esp_fifo_push(s, s->status);
899             esp_set_phase(s, STAT_MI);
900 
901             /* Process any message in phase data */
902             esp_do_nodma(s);
903             break;
904         }
905         break;
906 
907     case STAT_MI:
908         switch (s->rregs[ESP_CMD]) {
909         case CMD_ICCS:
910             esp_fifo_push(s, 0);
911 
912             /* Raise end of command interrupt */
913             s->rregs[ESP_RINTR] |= INTR_FC;
914             esp_raise_irq(s);
915             break;
916         }
917         break;
918     }
919 }
920 
921 void esp_command_complete(SCSIRequest *req, size_t resid)
922 {
923     ESPState *s = req->hba_private;
924     int to_device = (esp_get_phase(s) == STAT_DO);
925 
926     trace_esp_command_complete();
927 
928     /*
929      * Non-DMA transfers from the target will leave the last byte in
930      * the FIFO so don't reset ti_size in this case
931      */
932     if (s->dma || to_device) {
933         if (s->ti_size != 0) {
934             trace_esp_command_complete_unexpected();
935         }
936     }
937 
938     s->async_len = 0;
939     if (req->status) {
940         trace_esp_command_complete_fail();
941     }
942     s->status = req->status;
943 
944     /*
945      * Switch to status phase. For non-DMA transfers from the target the last
946      * byte is still in the FIFO
947      */
948     s->ti_size = 0;
949 
950     switch (s->rregs[ESP_CMD]) {
951     case CMD_SEL | CMD_DMA:
952     case CMD_SEL:
953     case CMD_SELATN | CMD_DMA:
954     case CMD_SELATN:
955         /*
956          * No data phase for sequencer command so raise deferred bus service
957          * and function complete interrupt
958          */
959         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
960         s->rregs[ESP_RSEQ] = SEQ_CD;
961         break;
962 
963     case CMD_TI | CMD_DMA:
964     case CMD_TI:
965         s->rregs[ESP_CMD] = 0;
966         break;
967     }
968 
969     /* Raise bus service interrupt to indicate change to STATUS phase */
970     esp_set_phase(s, STAT_ST);
971     s->rregs[ESP_RINTR] |= INTR_BS;
972     esp_raise_irq(s);
973 
974     /* Ensure DRQ is set correctly for TC underflow or normal completion */
975     esp_dma_ti_check(s);
976 
977     if (s->current_req) {
978         scsi_req_unref(s->current_req);
979         s->current_req = NULL;
980         s->current_dev = NULL;
981     }
982 }
983 
984 void esp_transfer_data(SCSIRequest *req, uint32_t len)
985 {
986     ESPState *s = req->hba_private;
987     uint32_t dmalen = esp_get_tc(s);
988 
989     trace_esp_transfer_data(dmalen, s->ti_size);
990     s->async_len = len;
991     s->async_buf = scsi_req_get_buf(req);
992 
993     if (!s->data_ready) {
994         s->data_ready = true;
995 
996         switch (s->rregs[ESP_CMD]) {
997         case CMD_SEL | CMD_DMA:
998         case CMD_SEL:
999         case CMD_SELATN | CMD_DMA:
1000         case CMD_SELATN:
1001             /*
1002              * Initial incoming data xfer is complete for sequencer command
1003              * so raise deferred bus service and function complete interrupt
1004              */
1005              s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
1006              s->rregs[ESP_RSEQ] = SEQ_CD;
1007              break;
1008 
1009         case CMD_SELATNS | CMD_DMA:
1010         case CMD_SELATNS:
1011             /*
1012              * Initial incoming data xfer is complete so raise command
1013              * completion interrupt
1014              */
1015              s->rregs[ESP_RINTR] |= INTR_BS;
1016              s->rregs[ESP_RSEQ] = SEQ_MO;
1017              break;
1018 
1019         case CMD_TI | CMD_DMA:
1020         case CMD_TI:
1021             /*
1022              * Bus service interrupt raised because of initial change to
1023              * DATA phase
1024              */
1025             s->rregs[ESP_CMD] = 0;
1026             s->rregs[ESP_RINTR] |= INTR_BS;
1027             break;
1028         }
1029 
1030         esp_raise_irq(s);
1031     }
1032 
1033     /*
1034      * Always perform the initial transfer upon reception of the next TI
1035      * command to ensure the DMA/non-DMA status of the command is correct.
1036      * It is not possible to use s->dma directly in the section below as
1037      * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
1038      * async data transfer is delayed then s->dma is set incorrectly.
1039      */
1040 
1041     if (s->rregs[ESP_CMD] == (CMD_TI | CMD_DMA)) {
1042         /* When the SCSI layer returns more data, raise deferred INTR_BS */
1043         esp_dma_ti_check(s);
1044 
1045         esp_do_dma(s);
1046     } else if (s->rregs[ESP_CMD] == CMD_TI) {
1047         esp_do_nodma(s);
1048     }
1049 }
1050 
1051 static void handle_ti(ESPState *s)
1052 {
1053     uint32_t dmalen;
1054 
1055     if (s->dma && !s->dma_enabled) {
1056         s->dma_cb = handle_ti;
1057         return;
1058     }
1059 
1060     if (s->dma) {
1061         dmalen = esp_get_tc(s);
1062         trace_esp_handle_ti(dmalen);
1063         esp_do_dma(s);
1064     } else {
1065         trace_esp_handle_ti(s->ti_size);
1066         esp_do_nodma(s);
1067 
1068         if (esp_get_phase(s) == STAT_DO) {
1069             esp_nodma_ti_dataout(s);
1070         }
1071     }
1072 }
1073 
1074 void esp_hard_reset(ESPState *s)
1075 {
1076     memset(s->rregs, 0, ESP_REGS);
1077     memset(s->wregs, 0, ESP_REGS);
1078     s->tchi_written = 0;
1079     s->ti_size = 0;
1080     s->async_len = 0;
1081     fifo8_reset(&s->fifo);
1082     fifo8_reset(&s->cmdfifo);
1083     s->dma = 0;
1084     s->dma_cb = NULL;
1085 
1086     s->rregs[ESP_CFG1] = 7;
1087 }
1088 
1089 static void esp_soft_reset(ESPState *s)
1090 {
1091     qemu_irq_lower(s->irq);
1092     qemu_irq_lower(s->drq_irq);
1093     esp_hard_reset(s);
1094 }
1095 
1096 static void esp_bus_reset(ESPState *s)
1097 {
1098     bus_cold_reset(BUS(&s->bus));
1099 }
1100 
1101 static void parent_esp_reset(ESPState *s, int irq, int level)
1102 {
1103     if (level) {
1104         esp_soft_reset(s);
1105     }
1106 }
1107 
1108 static void esp_run_cmd(ESPState *s)
1109 {
1110     uint8_t cmd = s->rregs[ESP_CMD];
1111 
1112     if (cmd & CMD_DMA) {
1113         s->dma = 1;
1114         /* Reload DMA counter.  */
1115         if (esp_get_stc(s) == 0) {
1116             esp_set_tc(s, 0x10000);
1117         } else {
1118             esp_set_tc(s, esp_get_stc(s));
1119         }
1120     } else {
1121         s->dma = 0;
1122     }
1123     switch (cmd & CMD_CMD) {
1124     case CMD_NOP:
1125         trace_esp_mem_writeb_cmd_nop(cmd);
1126         break;
1127     case CMD_FLUSH:
1128         trace_esp_mem_writeb_cmd_flush(cmd);
1129         fifo8_reset(&s->fifo);
1130         break;
1131     case CMD_RESET:
1132         trace_esp_mem_writeb_cmd_reset(cmd);
1133         esp_soft_reset(s);
1134         break;
1135     case CMD_BUSRESET:
1136         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1137         esp_bus_reset(s);
1138         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1139             s->rregs[ESP_RINTR] |= INTR_RST;
1140             esp_raise_irq(s);
1141         }
1142         break;
1143     case CMD_TI:
1144         trace_esp_mem_writeb_cmd_ti(cmd);
1145         handle_ti(s);
1146         break;
1147     case CMD_ICCS:
1148         trace_esp_mem_writeb_cmd_iccs(cmd);
1149         write_response(s);
1150         break;
1151     case CMD_MSGACC:
1152         trace_esp_mem_writeb_cmd_msgacc(cmd);
1153         s->rregs[ESP_RINTR] |= INTR_DC;
1154         s->rregs[ESP_RSEQ] = 0;
1155         s->rregs[ESP_RFLAGS] = 0;
1156         esp_raise_irq(s);
1157         break;
1158     case CMD_PAD:
1159         trace_esp_mem_writeb_cmd_pad(cmd);
1160         handle_pad(s);
1161         break;
1162     case CMD_SATN:
1163         trace_esp_mem_writeb_cmd_satn(cmd);
1164         break;
1165     case CMD_RSTATN:
1166         trace_esp_mem_writeb_cmd_rstatn(cmd);
1167         break;
1168     case CMD_SEL:
1169         trace_esp_mem_writeb_cmd_sel(cmd);
1170         handle_s_without_atn(s);
1171         break;
1172     case CMD_SELATN:
1173         trace_esp_mem_writeb_cmd_selatn(cmd);
1174         handle_satn(s);
1175         break;
1176     case CMD_SELATNS:
1177         trace_esp_mem_writeb_cmd_selatns(cmd);
1178         handle_satn_stop(s);
1179         break;
1180     case CMD_ENSEL:
1181         trace_esp_mem_writeb_cmd_ensel(cmd);
1182         s->rregs[ESP_RINTR] = 0;
1183         break;
1184     case CMD_DISSEL:
1185         trace_esp_mem_writeb_cmd_dissel(cmd);
1186         s->rregs[ESP_RINTR] = 0;
1187         esp_raise_irq(s);
1188         break;
1189     default:
1190         trace_esp_error_unhandled_command(cmd);
1191         break;
1192     }
1193 }
1194 
1195 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1196 {
1197     uint32_t val;
1198 
1199     switch (saddr) {
1200     case ESP_FIFO:
1201         s->rregs[ESP_FIFO] = esp_fifo_pop(s);
1202         val = s->rregs[ESP_FIFO];
1203         break;
1204     case ESP_RINTR:
1205         /*
1206          * Clear sequence step, interrupt register and all status bits
1207          * except TC
1208          */
1209         val = s->rregs[ESP_RINTR];
1210         s->rregs[ESP_RINTR] = 0;
1211         esp_lower_irq(s);
1212         s->rregs[ESP_RSTAT] &= STAT_TC | 7;
1213         /*
1214          * According to the datasheet ESP_RSEQ should be cleared, but as the
1215          * emulation currently defers information transfers to the next TI
1216          * command leave it for now so that pedantic guests such as the old
1217          * Linux 2.6 driver see the correct flags before the next SCSI phase
1218          * transition.
1219          *
1220          * s->rregs[ESP_RSEQ] = SEQ_0;
1221          */
1222         break;
1223     case ESP_TCHI:
1224         /* Return the unique id if the value has never been written */
1225         if (!s->tchi_written) {
1226             val = s->chip_id;
1227         } else {
1228             val = s->rregs[saddr];
1229         }
1230         break;
1231      case ESP_RFLAGS:
1232         /* Bottom 5 bits indicate number of bytes in FIFO */
1233         val = fifo8_num_used(&s->fifo);
1234         break;
1235     default:
1236         val = s->rregs[saddr];
1237         break;
1238     }
1239 
1240     trace_esp_mem_readb(saddr, val);
1241     return val;
1242 }
1243 
1244 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1245 {
1246     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1247     switch (saddr) {
1248     case ESP_TCHI:
1249         s->tchi_written = true;
1250         /* fall through */
1251     case ESP_TCLO:
1252     case ESP_TCMID:
1253         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1254         break;
1255     case ESP_FIFO:
1256         if (!fifo8_is_full(&s->fifo)) {
1257             esp_fifo_push(s, val);
1258         }
1259         esp_do_nodma(s);
1260         break;
1261     case ESP_CMD:
1262         s->rregs[saddr] = val;
1263         esp_run_cmd(s);
1264         break;
1265     case ESP_WBUSID ... ESP_WSYNO:
1266         break;
1267     case ESP_CFG1:
1268     case ESP_CFG2: case ESP_CFG3:
1269     case ESP_RES3: case ESP_RES4:
1270         s->rregs[saddr] = val;
1271         break;
1272     case ESP_WCCF ... ESP_WTEST:
1273         break;
1274     default:
1275         trace_esp_error_invalid_write(val, saddr);
1276         return;
1277     }
1278     s->wregs[saddr] = val;
1279 }
1280 
1281 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1282                             unsigned size, bool is_write,
1283                             MemTxAttrs attrs)
1284 {
1285     return (size == 1) || (is_write && size == 4);
1286 }
1287 
1288 static bool esp_is_before_version_5(void *opaque, int version_id)
1289 {
1290     ESPState *s = ESP(opaque);
1291 
1292     version_id = MIN(version_id, s->mig_version_id);
1293     return version_id < 5;
1294 }
1295 
1296 static bool esp_is_version_5(void *opaque, int version_id)
1297 {
1298     ESPState *s = ESP(opaque);
1299 
1300     version_id = MIN(version_id, s->mig_version_id);
1301     return version_id >= 5;
1302 }
1303 
1304 static bool esp_is_version_6(void *opaque, int version_id)
1305 {
1306     ESPState *s = ESP(opaque);
1307 
1308     version_id = MIN(version_id, s->mig_version_id);
1309     return version_id >= 6;
1310 }
1311 
1312 static bool esp_is_between_version_5_and_6(void *opaque, int version_id)
1313 {
1314     ESPState *s = ESP(opaque);
1315 
1316     version_id = MIN(version_id, s->mig_version_id);
1317     return version_id >= 5 && version_id <= 6;
1318 }
1319 
1320 int esp_pre_save(void *opaque)
1321 {
1322     ESPState *s = ESP(object_resolve_path_component(
1323                       OBJECT(opaque), "esp"));
1324 
1325     s->mig_version_id = vmstate_esp.version_id;
1326     return 0;
1327 }
1328 
1329 static int esp_post_load(void *opaque, int version_id)
1330 {
1331     ESPState *s = ESP(opaque);
1332     int len, i;
1333 
1334     version_id = MIN(version_id, s->mig_version_id);
1335 
1336     if (version_id < 5) {
1337         esp_set_tc(s, s->mig_dma_left);
1338 
1339         /* Migrate ti_buf to fifo */
1340         len = s->mig_ti_wptr - s->mig_ti_rptr;
1341         for (i = 0; i < len; i++) {
1342             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1343         }
1344 
1345         /* Migrate cmdbuf to cmdfifo */
1346         for (i = 0; i < s->mig_cmdlen; i++) {
1347             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1348         }
1349     }
1350 
1351     s->mig_version_id = vmstate_esp.version_id;
1352     return 0;
1353 }
1354 
1355 const VMStateDescription vmstate_esp = {
1356     .name = "esp",
1357     .version_id = 7,
1358     .minimum_version_id = 3,
1359     .post_load = esp_post_load,
1360     .fields = (const VMStateField[]) {
1361         VMSTATE_BUFFER(rregs, ESPState),
1362         VMSTATE_BUFFER(wregs, ESPState),
1363         VMSTATE_INT32(ti_size, ESPState),
1364         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1365         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1366         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1367         VMSTATE_UINT32(status, ESPState),
1368         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1369                             esp_is_before_version_5),
1370         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1371                           esp_is_before_version_5),
1372         VMSTATE_UINT32(dma, ESPState),
1373         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1374                               esp_is_before_version_5, 0, 16),
1375         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1376                               esp_is_before_version_5, 16,
1377                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1378         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1379         VMSTATE_UINT32(do_cmd, ESPState),
1380         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1381         VMSTATE_BOOL_TEST(data_ready, ESPState, esp_is_version_5),
1382         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1383         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1384         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1385         VMSTATE_UINT8_TEST(mig_ti_cmd, ESPState,
1386                            esp_is_between_version_5_and_6),
1387         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1388         VMSTATE_BOOL(drq_state, ESPState),
1389         VMSTATE_END_OF_LIST()
1390     },
1391 };
1392 
1393 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1394                                  uint64_t val, unsigned int size)
1395 {
1396     SysBusESPState *sysbus = opaque;
1397     ESPState *s = ESP(&sysbus->esp);
1398     uint32_t saddr;
1399 
1400     saddr = addr >> sysbus->it_shift;
1401     esp_reg_write(s, saddr, val);
1402 }
1403 
1404 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1405                                     unsigned int size)
1406 {
1407     SysBusESPState *sysbus = opaque;
1408     ESPState *s = ESP(&sysbus->esp);
1409     uint32_t saddr;
1410 
1411     saddr = addr >> sysbus->it_shift;
1412     return esp_reg_read(s, saddr);
1413 }
1414 
1415 static const MemoryRegionOps sysbus_esp_mem_ops = {
1416     .read = sysbus_esp_mem_read,
1417     .write = sysbus_esp_mem_write,
1418     .endianness = DEVICE_NATIVE_ENDIAN,
1419     .valid.accepts = esp_mem_accepts,
1420 };
1421 
1422 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1423                                   uint64_t val, unsigned int size)
1424 {
1425     SysBusESPState *sysbus = opaque;
1426     ESPState *s = ESP(&sysbus->esp);
1427 
1428     trace_esp_pdma_write(size);
1429 
1430     switch (size) {
1431     case 1:
1432         esp_pdma_write(s, val);
1433         break;
1434     case 2:
1435         esp_pdma_write(s, val >> 8);
1436         esp_pdma_write(s, val);
1437         break;
1438     }
1439     esp_do_dma(s);
1440 }
1441 
1442 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1443                                      unsigned int size)
1444 {
1445     SysBusESPState *sysbus = opaque;
1446     ESPState *s = ESP(&sysbus->esp);
1447     uint64_t val = 0;
1448 
1449     trace_esp_pdma_read(size);
1450 
1451     switch (size) {
1452     case 1:
1453         val = esp_pdma_read(s);
1454         break;
1455     case 2:
1456         val = esp_pdma_read(s);
1457         val = (val << 8) | esp_pdma_read(s);
1458         break;
1459     }
1460     esp_do_dma(s);
1461     return val;
1462 }
1463 
1464 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1465 {
1466     ESPState *s = container_of(req->bus, ESPState, bus);
1467 
1468     scsi_req_ref(req);
1469     s->current_req = req;
1470     return s;
1471 }
1472 
1473 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1474     .read = sysbus_esp_pdma_read,
1475     .write = sysbus_esp_pdma_write,
1476     .endianness = DEVICE_NATIVE_ENDIAN,
1477     .valid.min_access_size = 1,
1478     .valid.max_access_size = 4,
1479     .impl.min_access_size = 1,
1480     .impl.max_access_size = 2,
1481 };
1482 
1483 static const struct SCSIBusInfo esp_scsi_info = {
1484     .tcq = false,
1485     .max_target = ESP_MAX_DEVS,
1486     .max_lun = 7,
1487 
1488     .load_request = esp_load_request,
1489     .transfer_data = esp_transfer_data,
1490     .complete = esp_command_complete,
1491     .cancel = esp_request_cancelled
1492 };
1493 
1494 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1495 {
1496     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1497     ESPState *s = ESP(&sysbus->esp);
1498 
1499     switch (irq) {
1500     case 0:
1501         parent_esp_reset(s, irq, level);
1502         break;
1503     case 1:
1504         esp_dma_enable(s, irq, level);
1505         break;
1506     }
1507 }
1508 
1509 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1510 {
1511     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1512     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1513     ESPState *s = ESP(&sysbus->esp);
1514 
1515     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1516         return;
1517     }
1518 
1519     sysbus_init_irq(sbd, &s->irq);
1520     sysbus_init_irq(sbd, &s->drq_irq);
1521     assert(sysbus->it_shift != -1);
1522 
1523     s->chip_id = TCHI_FAS100A;
1524     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1525                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1526     sysbus_init_mmio(sbd, &sysbus->iomem);
1527     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1528                           sysbus, "esp-pdma", 4);
1529     sysbus_init_mmio(sbd, &sysbus->pdma);
1530 
1531     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1532 
1533     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1534 }
1535 
1536 static void sysbus_esp_hard_reset(DeviceState *dev)
1537 {
1538     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1539     ESPState *s = ESP(&sysbus->esp);
1540 
1541     esp_hard_reset(s);
1542 }
1543 
1544 static void sysbus_esp_init(Object *obj)
1545 {
1546     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1547 
1548     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1549 }
1550 
1551 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1552     .name = "sysbusespscsi",
1553     .version_id = 2,
1554     .minimum_version_id = 1,
1555     .pre_save = esp_pre_save,
1556     .fields = (const VMStateField[]) {
1557         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1558         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1559         VMSTATE_END_OF_LIST()
1560     }
1561 };
1562 
1563 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1564 {
1565     DeviceClass *dc = DEVICE_CLASS(klass);
1566 
1567     dc->realize = sysbus_esp_realize;
1568     dc->reset = sysbus_esp_hard_reset;
1569     dc->vmsd = &vmstate_sysbus_esp_scsi;
1570     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1571 }
1572 
1573 static void esp_finalize(Object *obj)
1574 {
1575     ESPState *s = ESP(obj);
1576 
1577     fifo8_destroy(&s->fifo);
1578     fifo8_destroy(&s->cmdfifo);
1579 }
1580 
1581 static void esp_init(Object *obj)
1582 {
1583     ESPState *s = ESP(obj);
1584 
1585     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1586     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1587 }
1588 
1589 static void esp_class_init(ObjectClass *klass, void *data)
1590 {
1591     DeviceClass *dc = DEVICE_CLASS(klass);
1592 
1593     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1594     dc->user_creatable = false;
1595     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1596 }
1597 
1598 static const TypeInfo esp_info_types[] = {
1599     {
1600         .name          = TYPE_SYSBUS_ESP,
1601         .parent        = TYPE_SYS_BUS_DEVICE,
1602         .instance_init = sysbus_esp_init,
1603         .instance_size = sizeof(SysBusESPState),
1604         .class_init    = sysbus_esp_class_init,
1605     },
1606     {
1607         .name = TYPE_ESP,
1608         .parent = TYPE_DEVICE,
1609         .instance_init = esp_init,
1610         .instance_finalize = esp_finalize,
1611         .instance_size = sizeof(ESPState),
1612         .class_init = esp_class_init,
1613     },
1614 };
1615 
1616 DEFINE_TYPES(esp_info_types)
1617