xref: /qemu/hw/scsi/esp.c (revision c5bd505524303bd8cb9eaf5d44ca7e1713d27f90)
1 /*
2  * QEMU ESP/NCR53C9x emulation
3  *
4  * Copyright (c) 2005-2006 Fabrice Bellard
5  * Copyright (c) 2012 Herve Poussineau
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "hw/sysbus.h"
28 #include "migration/vmstate.h"
29 #include "hw/irq.h"
30 #include "hw/scsi/esp.h"
31 #include "trace.h"
32 #include "qemu/log.h"
33 #include "qemu/module.h"
34 
35 /*
36  * On Sparc32, this is the ESP (NCR53C90) part of chip STP2000 (Master I/O),
37  * also produced as NCR89C100. See
38  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
39  * and
40  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR53C9X.txt
41  *
42  * On Macintosh Quadra it is a NCR53C96.
43  */
44 
45 static void esp_raise_irq(ESPState *s)
46 {
47     if (!(s->rregs[ESP_RSTAT] & STAT_INT)) {
48         s->rregs[ESP_RSTAT] |= STAT_INT;
49         qemu_irq_raise(s->irq);
50         trace_esp_raise_irq();
51     }
52 }
53 
54 static void esp_lower_irq(ESPState *s)
55 {
56     if (s->rregs[ESP_RSTAT] & STAT_INT) {
57         s->rregs[ESP_RSTAT] &= ~STAT_INT;
58         qemu_irq_lower(s->irq);
59         trace_esp_lower_irq();
60     }
61 }
62 
63 static void esp_raise_drq(ESPState *s)
64 {
65     qemu_irq_raise(s->irq_data);
66     trace_esp_raise_drq();
67 }
68 
69 static void esp_lower_drq(ESPState *s)
70 {
71     qemu_irq_lower(s->irq_data);
72     trace_esp_lower_drq();
73 }
74 
75 void esp_dma_enable(ESPState *s, int irq, int level)
76 {
77     if (level) {
78         s->dma_enabled = 1;
79         trace_esp_dma_enable();
80         if (s->dma_cb) {
81             s->dma_cb(s);
82             s->dma_cb = NULL;
83         }
84     } else {
85         trace_esp_dma_disable();
86         s->dma_enabled = 0;
87     }
88 }
89 
90 void esp_request_cancelled(SCSIRequest *req)
91 {
92     ESPState *s = req->hba_private;
93 
94     if (req == s->current_req) {
95         scsi_req_unref(s->current_req);
96         s->current_req = NULL;
97         s->current_dev = NULL;
98         s->async_len = 0;
99     }
100 }
101 
102 static void esp_fifo_push(Fifo8 *fifo, uint8_t val)
103 {
104     if (fifo8_num_used(fifo) == fifo->capacity) {
105         trace_esp_error_fifo_overrun();
106         return;
107     }
108 
109     fifo8_push(fifo, val);
110 }
111 
112 static uint8_t esp_fifo_pop(Fifo8 *fifo)
113 {
114     if (fifo8_is_empty(fifo)) {
115         return 0;
116     }
117 
118     return fifo8_pop(fifo);
119 }
120 
121 static uint32_t esp_fifo_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen)
122 {
123     const uint8_t *buf;
124     uint32_t n, n2;
125     int len;
126 
127     if (maxlen == 0) {
128         return 0;
129     }
130 
131     len = maxlen;
132     buf = fifo8_pop_buf(fifo, len, &n);
133     if (dest) {
134         memcpy(dest, buf, n);
135     }
136 
137     /* Add FIFO wraparound if needed */
138     len -= n;
139     len = MIN(len, fifo8_num_used(fifo));
140     if (len) {
141         buf = fifo8_pop_buf(fifo, len, &n2);
142         if (dest) {
143             memcpy(&dest[n], buf, n2);
144         }
145         n += n2;
146     }
147 
148     return n;
149 }
150 
151 static uint32_t esp_get_tc(ESPState *s)
152 {
153     uint32_t dmalen;
154 
155     dmalen = s->rregs[ESP_TCLO];
156     dmalen |= s->rregs[ESP_TCMID] << 8;
157     dmalen |= s->rregs[ESP_TCHI] << 16;
158 
159     return dmalen;
160 }
161 
162 static void esp_set_tc(ESPState *s, uint32_t dmalen)
163 {
164     uint32_t old_tc = esp_get_tc(s);
165 
166     s->rregs[ESP_TCLO] = dmalen;
167     s->rregs[ESP_TCMID] = dmalen >> 8;
168     s->rregs[ESP_TCHI] = dmalen >> 16;
169 
170     if (old_tc && dmalen == 0) {
171         s->rregs[ESP_RSTAT] |= STAT_TC;
172     }
173 }
174 
175 static uint32_t esp_get_stc(ESPState *s)
176 {
177     uint32_t dmalen;
178 
179     dmalen = s->wregs[ESP_TCLO];
180     dmalen |= s->wregs[ESP_TCMID] << 8;
181     dmalen |= s->wregs[ESP_TCHI] << 16;
182 
183     return dmalen;
184 }
185 
186 static const char *esp_phase_names[8] = {
187     "DATA OUT", "DATA IN", "COMMAND", "STATUS",
188     "(reserved)", "(reserved)", "MESSAGE OUT", "MESSAGE IN"
189 };
190 
191 static void esp_set_phase(ESPState *s, uint8_t phase)
192 {
193     s->rregs[ESP_RSTAT] &= ~7;
194     s->rregs[ESP_RSTAT] |= phase;
195 
196     trace_esp_set_phase(esp_phase_names[phase]);
197 }
198 
199 static uint8_t esp_pdma_read(ESPState *s)
200 {
201     uint8_t val;
202 
203     val = esp_fifo_pop(&s->fifo);
204     return val;
205 }
206 
207 static void esp_pdma_write(ESPState *s, uint8_t val)
208 {
209     uint32_t dmalen = esp_get_tc(s);
210 
211     if (dmalen == 0) {
212         return;
213     }
214 
215     esp_fifo_push(&s->fifo, val);
216 
217     dmalen--;
218     esp_set_tc(s, dmalen);
219 }
220 
221 static void esp_set_pdma_cb(ESPState *s, enum pdma_cb cb)
222 {
223     s->pdma_cb = cb;
224 }
225 
226 static int esp_select(ESPState *s)
227 {
228     int target;
229 
230     target = s->wregs[ESP_WBUSID] & BUSID_DID;
231 
232     s->ti_size = 0;
233 
234     if (s->current_req) {
235         /* Started a new command before the old one finished. Cancel it. */
236         scsi_req_cancel(s->current_req);
237     }
238 
239     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
240     if (!s->current_dev) {
241         /* No such drive */
242         s->rregs[ESP_RSTAT] = 0;
243         s->rregs[ESP_RINTR] = INTR_DC;
244         s->rregs[ESP_RSEQ] = SEQ_0;
245         esp_raise_irq(s);
246         return -1;
247     }
248 
249     /*
250      * Note that we deliberately don't raise the IRQ here: this will be done
251      * either in do_command_phase() for DATA OUT transfers or by the deferred
252      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
253      */
254     s->rregs[ESP_RINTR] |= INTR_FC;
255     s->rregs[ESP_RSEQ] = SEQ_CD;
256     return 0;
257 }
258 
259 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
260 {
261     uint8_t buf[ESP_CMDFIFO_SZ];
262     uint32_t dmalen, n;
263     int target;
264 
265     target = s->wregs[ESP_WBUSID] & BUSID_DID;
266     if (s->dma) {
267         dmalen = MIN(esp_get_tc(s), maxlen);
268         if (dmalen == 0) {
269             return 0;
270         }
271         if (s->dma_memory_read) {
272             s->dma_memory_read(s->dma_opaque, buf, dmalen);
273             dmalen = MIN(fifo8_num_free(&s->cmdfifo), dmalen);
274             fifo8_push_all(&s->cmdfifo, buf, dmalen);
275             esp_set_tc(s, esp_get_tc(s) - dmalen);
276         } else {
277             return 0;
278         }
279     } else {
280         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
281         if (dmalen == 0) {
282             return 0;
283         }
284         n = esp_fifo_pop_buf(&s->fifo, buf, dmalen);
285         n = MIN(fifo8_num_free(&s->cmdfifo), n);
286         fifo8_push_all(&s->cmdfifo, buf, n);
287     }
288     trace_esp_get_cmd(dmalen, target);
289 
290     return dmalen;
291 }
292 
293 static void do_command_phase(ESPState *s)
294 {
295     uint32_t cmdlen;
296     int32_t datalen;
297     SCSIDevice *current_lun;
298     uint8_t buf[ESP_CMDFIFO_SZ];
299 
300     trace_esp_do_command_phase(s->lun);
301     cmdlen = fifo8_num_used(&s->cmdfifo);
302     if (!cmdlen || !s->current_dev) {
303         return;
304     }
305     esp_fifo_pop_buf(&s->cmdfifo, buf, cmdlen);
306 
307     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
308     if (!current_lun) {
309         /* No such drive */
310         s->rregs[ESP_RSTAT] = 0;
311         s->rregs[ESP_RINTR] = INTR_DC;
312         s->rregs[ESP_RSEQ] = SEQ_0;
313         esp_raise_irq(s);
314         return;
315     }
316 
317     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
318     datalen = scsi_req_enqueue(s->current_req);
319     s->ti_size = datalen;
320     fifo8_reset(&s->cmdfifo);
321     if (datalen != 0) {
322         s->ti_cmd = 0;
323         if (datalen > 0) {
324             /*
325              * Switch to DATA IN phase but wait until initial data xfer is
326              * complete before raising the command completion interrupt
327              */
328             s->data_in_ready = false;
329             esp_set_phase(s, STAT_DI);
330         } else {
331             esp_set_phase(s, STAT_DO);
332             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
333             esp_raise_irq(s);
334             esp_lower_drq(s);
335         }
336         scsi_req_continue(s->current_req);
337         return;
338     }
339 }
340 
341 static void do_message_phase(ESPState *s)
342 {
343     if (s->cmdfifo_cdb_offset) {
344         uint8_t message = esp_fifo_pop(&s->cmdfifo);
345 
346         trace_esp_do_identify(message);
347         s->lun = message & 7;
348         s->cmdfifo_cdb_offset--;
349     }
350 
351     /* Ignore extended messages for now */
352     if (s->cmdfifo_cdb_offset) {
353         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
354         esp_fifo_pop_buf(&s->cmdfifo, NULL, len);
355         s->cmdfifo_cdb_offset = 0;
356     }
357 }
358 
359 static void do_cmd(ESPState *s)
360 {
361     do_message_phase(s);
362     assert(s->cmdfifo_cdb_offset == 0);
363     do_command_phase(s);
364 }
365 
366 static void satn_pdma_cb(ESPState *s)
367 {
368     uint8_t buf[ESP_FIFO_SZ];
369     int n;
370 
371     /* Copy FIFO into cmdfifo */
372     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
373     n = MIN(fifo8_num_free(&s->cmdfifo), n);
374     fifo8_push_all(&s->cmdfifo, buf, n);
375 
376     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
377         s->cmdfifo_cdb_offset = 1;
378         s->do_cmd = 0;
379         do_cmd(s);
380     }
381 }
382 
383 static void handle_satn(ESPState *s)
384 {
385     int32_t cmdlen;
386 
387     if (s->dma && !s->dma_enabled) {
388         s->dma_cb = handle_satn;
389         return;
390     }
391     esp_set_pdma_cb(s, SATN_PDMA_CB);
392     if (esp_select(s) < 0) {
393         return;
394     }
395     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
396     if (cmdlen > 0) {
397         s->cmdfifo_cdb_offset = 1;
398         s->do_cmd = 0;
399         do_cmd(s);
400     } else if (cmdlen == 0) {
401         if (s->dma) {
402             esp_raise_drq(s);
403         }
404         s->do_cmd = 1;
405         /* Target present, but no cmd yet - switch to command phase */
406         s->rregs[ESP_RSEQ] = SEQ_CD;
407         esp_set_phase(s, STAT_CD);
408     }
409 }
410 
411 static void s_without_satn_pdma_cb(ESPState *s)
412 {
413     uint8_t buf[ESP_FIFO_SZ];
414     int n;
415 
416     /* Copy FIFO into cmdfifo */
417     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
418     n = MIN(fifo8_num_free(&s->cmdfifo), n);
419     fifo8_push_all(&s->cmdfifo, buf, n);
420 
421     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
422         s->cmdfifo_cdb_offset = 0;
423         s->do_cmd = 0;
424         do_cmd(s);
425     }
426 }
427 
428 static void handle_s_without_atn(ESPState *s)
429 {
430     int32_t cmdlen;
431 
432     if (s->dma && !s->dma_enabled) {
433         s->dma_cb = handle_s_without_atn;
434         return;
435     }
436     esp_set_pdma_cb(s, S_WITHOUT_SATN_PDMA_CB);
437     if (esp_select(s) < 0) {
438         return;
439     }
440     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
441     if (cmdlen > 0) {
442         s->cmdfifo_cdb_offset = 0;
443         s->do_cmd = 0;
444         do_cmd(s);
445     } else if (cmdlen == 0) {
446         if (s->dma) {
447             esp_raise_drq(s);
448         }
449         s->do_cmd = 1;
450         /* Target present, but no cmd yet - switch to command phase */
451         s->rregs[ESP_RSEQ] = SEQ_CD;
452         esp_set_phase(s, STAT_CD);
453     }
454 }
455 
456 static void satn_stop_pdma_cb(ESPState *s)
457 {
458     uint8_t buf[ESP_FIFO_SZ];
459     int n;
460 
461     /* Copy FIFO into cmdfifo */
462     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
463     n = MIN(fifo8_num_free(&s->cmdfifo), n);
464     fifo8_push_all(&s->cmdfifo, buf, n);
465 
466     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
467         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
468         s->do_cmd = 1;
469         s->cmdfifo_cdb_offset = 1;
470         esp_set_phase(s, STAT_CD);
471         s->rregs[ESP_RSTAT] |= STAT_TC;
472         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
473         s->rregs[ESP_RSEQ] = SEQ_CD;
474         esp_raise_irq(s);
475     }
476 }
477 
478 static void handle_satn_stop(ESPState *s)
479 {
480     int32_t cmdlen;
481 
482     if (s->dma && !s->dma_enabled) {
483         s->dma_cb = handle_satn_stop;
484         return;
485     }
486     esp_set_pdma_cb(s, SATN_STOP_PDMA_CB);
487     if (esp_select(s) < 0) {
488         return;
489     }
490     cmdlen = get_cmd(s, 1);
491     if (cmdlen > 0) {
492         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
493         s->do_cmd = 1;
494         s->cmdfifo_cdb_offset = 1;
495         esp_set_phase(s, STAT_MO);
496         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
497         s->rregs[ESP_RSEQ] = SEQ_MO;
498         esp_raise_irq(s);
499     } else if (cmdlen == 0) {
500         if (s->dma) {
501             esp_raise_drq(s);
502         }
503         s->do_cmd = 1;
504         /* Target present, switch to message out phase */
505         s->rregs[ESP_RSEQ] = SEQ_MO;
506         esp_set_phase(s, STAT_MO);
507     }
508 }
509 
510 static void write_response_pdma_cb(ESPState *s)
511 {
512     esp_set_phase(s, STAT_ST);
513     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
514     s->rregs[ESP_RSEQ] = SEQ_CD;
515     esp_raise_irq(s);
516 }
517 
518 static void write_response(ESPState *s)
519 {
520     uint8_t buf[2];
521 
522     trace_esp_write_response(s->status);
523 
524     buf[0] = s->status;
525     buf[1] = 0;
526 
527     if (s->dma) {
528         if (s->dma_memory_write) {
529             s->dma_memory_write(s->dma_opaque, buf, 2);
530             esp_set_phase(s, STAT_ST);
531             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
532             s->rregs[ESP_RSEQ] = SEQ_CD;
533         } else {
534             esp_set_pdma_cb(s, WRITE_RESPONSE_PDMA_CB);
535             esp_raise_drq(s);
536             return;
537         }
538     } else {
539         fifo8_reset(&s->fifo);
540         fifo8_push_all(&s->fifo, buf, 2);
541         s->rregs[ESP_RFLAGS] = 2;
542     }
543     esp_raise_irq(s);
544 }
545 
546 static void esp_dma_done(ESPState *s)
547 {
548     s->rregs[ESP_RINTR] |= INTR_BS;
549     esp_raise_irq(s);
550 }
551 
552 static void do_dma_pdma_cb(ESPState *s)
553 {
554     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
555     uint8_t buf[ESP_CMDFIFO_SZ];
556     int len;
557     uint32_t n;
558 
559     if (s->do_cmd) {
560         /* Copy FIFO into cmdfifo */
561         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
562         n = MIN(fifo8_num_free(&s->cmdfifo), n);
563         fifo8_push_all(&s->cmdfifo, buf, n);
564 
565         /* Ensure we have received complete command after SATN and stop */
566         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
567             return;
568         }
569 
570         s->ti_size = 0;
571         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
572             /* No command received */
573             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
574                 return;
575             }
576 
577             /* Command has been received */
578             s->do_cmd = 0;
579             do_cmd(s);
580         } else {
581             /*
582              * Extra message out bytes received: update cmdfifo_cdb_offset
583              * and then switch to command phase
584              */
585             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
586             esp_set_phase(s, STAT_CD);
587             s->rregs[ESP_RSEQ] = SEQ_CD;
588             s->rregs[ESP_RINTR] |= INTR_BS;
589             esp_raise_irq(s);
590         }
591         return;
592     }
593 
594     if (!s->current_req) {
595         return;
596     }
597 
598     if (to_device) {
599         /* Copy FIFO data to device */
600         len = MIN(s->async_len, ESP_FIFO_SZ);
601         len = MIN(len, fifo8_num_used(&s->fifo));
602         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
603         s->async_buf += n;
604         s->async_len -= n;
605         s->ti_size += n;
606 
607         if (n < len) {
608             /* Unaligned accesses can cause FIFO wraparound */
609             len = len - n;
610             n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
611             s->async_buf += n;
612             s->async_len -= n;
613             s->ti_size += n;
614         }
615 
616         if (s->async_len == 0) {
617             scsi_req_continue(s->current_req);
618             return;
619         }
620 
621         if (esp_get_tc(s) == 0) {
622             esp_lower_drq(s);
623             esp_dma_done(s);
624         }
625 
626         return;
627     } else {
628         if (s->async_len == 0) {
629             /* Defer until the scsi layer has completed */
630             scsi_req_continue(s->current_req);
631             s->data_in_ready = false;
632             return;
633         }
634 
635         if (esp_get_tc(s) == 0) {
636             esp_lower_drq(s);
637             esp_dma_done(s);
638         }
639 
640         /* Copy device data to FIFO */
641         len = MIN(s->async_len, esp_get_tc(s));
642         len = MIN(len, fifo8_num_free(&s->fifo));
643         fifo8_push_all(&s->fifo, s->async_buf, len);
644         s->async_buf += len;
645         s->async_len -= len;
646         s->ti_size -= len;
647         esp_set_tc(s, esp_get_tc(s) - len);
648     }
649 }
650 
651 static void esp_do_dma(ESPState *s)
652 {
653     uint32_t len, cmdlen;
654     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
655     uint8_t buf[ESP_CMDFIFO_SZ];
656 
657     len = esp_get_tc(s);
658     if (s->do_cmd) {
659         /*
660          * handle_ti_cmd() case: esp_do_dma() is called only from
661          * handle_ti_cmd() with do_cmd != NULL (see the assert())
662          */
663         cmdlen = fifo8_num_used(&s->cmdfifo);
664         trace_esp_do_dma(cmdlen, len);
665         if (s->dma_memory_read) {
666             len = MIN(len, fifo8_num_free(&s->cmdfifo));
667             s->dma_memory_read(s->dma_opaque, buf, len);
668             fifo8_push_all(&s->cmdfifo, buf, len);
669             esp_set_tc(s, esp_get_tc(s) - len);
670         } else {
671             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
672             esp_raise_drq(s);
673             return;
674         }
675         trace_esp_handle_ti_cmd(cmdlen);
676         s->ti_size = 0;
677         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
678             /* No command received */
679             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
680                 return;
681             }
682 
683             /* Command has been received */
684             s->do_cmd = 0;
685             do_cmd(s);
686         } else {
687             /*
688              * Extra message out bytes received: update cmdfifo_cdb_offset
689              * and then switch to command phase
690              */
691             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
692             esp_set_phase(s, STAT_CD);
693             s->rregs[ESP_RSEQ] = SEQ_CD;
694             s->rregs[ESP_RINTR] |= INTR_BS;
695             esp_raise_irq(s);
696         }
697         return;
698     }
699     if (!s->current_req) {
700         return;
701     }
702     if (s->async_len == 0) {
703         /* Defer until data is available.  */
704         return;
705     }
706     if (len > s->async_len) {
707         len = s->async_len;
708     }
709     if (to_device) {
710         if (s->dma_memory_read) {
711             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
712 
713             esp_set_tc(s, esp_get_tc(s) - len);
714             s->async_buf += len;
715             s->async_len -= len;
716             s->ti_size += len;
717 
718             if (s->async_len == 0) {
719                 scsi_req_continue(s->current_req);
720                 /*
721                  * If there is still data to be read from the device then
722                  * complete the DMA operation immediately.  Otherwise defer
723                  * until the scsi layer has completed.
724                  */
725                 return;
726             }
727 
728             if (esp_get_tc(s) == 0) {
729                 /* Partially filled a scsi buffer. Complete immediately.  */
730                 esp_dma_done(s);
731                 esp_lower_drq(s);
732             }
733         } else {
734             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
735             esp_raise_drq(s);
736         }
737     } else {
738         if (s->dma_memory_write) {
739             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
740 
741             esp_set_tc(s, esp_get_tc(s) - len);
742             s->async_buf += len;
743             s->async_len -= len;
744             s->ti_size -= len;
745 
746             if (s->async_len == 0) {
747                 scsi_req_continue(s->current_req);
748             }
749 
750             if (esp_get_tc(s) == 0) {
751                 /* Partially filled a scsi buffer. Complete immediately.  */
752                 esp_dma_done(s);
753                 esp_lower_drq(s);
754             }
755         } else {
756             /* Adjust TC for any leftover data in the FIFO */
757             if (!fifo8_is_empty(&s->fifo)) {
758                 esp_set_tc(s, esp_get_tc(s) - fifo8_num_used(&s->fifo));
759             }
760 
761             /* Copy device data to FIFO */
762             len = MIN(len, fifo8_num_free(&s->fifo));
763             fifo8_push_all(&s->fifo, s->async_buf, len);
764             s->async_buf += len;
765             s->async_len -= len;
766             s->ti_size -= len;
767             esp_set_tc(s, esp_get_tc(s) - len);
768             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
769             esp_raise_drq(s);
770         }
771     }
772 }
773 
774 static void esp_do_nodma(ESPState *s)
775 {
776     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
777     uint8_t buf[ESP_FIFO_SZ];
778     uint32_t cmdlen;
779     int len, n;
780 
781     if (s->do_cmd) {
782         /* Copy FIFO into cmdfifo */
783         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
784         n = MIN(fifo8_num_free(&s->cmdfifo), n);
785         fifo8_push_all(&s->cmdfifo, buf, n);
786 
787         cmdlen = fifo8_num_used(&s->cmdfifo);
788         trace_esp_handle_ti_cmd(cmdlen);
789         s->ti_size = 0;
790         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
791             /* No command received */
792             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
793                 return;
794             }
795 
796             /* Command has been received */
797             s->do_cmd = 0;
798             do_cmd(s);
799         } else {
800             /*
801              * Extra message out bytes received: update cmdfifo_cdb_offset
802              * and then switch to command phase
803              */
804             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
805             esp_set_phase(s, STAT_CD);
806             s->rregs[ESP_RSEQ] = SEQ_CD;
807             s->rregs[ESP_RINTR] |= INTR_BS;
808             esp_raise_irq(s);
809         }
810         return;
811     }
812 
813     if (!s->current_req) {
814         return;
815     }
816 
817     if (s->async_len == 0) {
818         /* Defer until data is available.  */
819         return;
820     }
821 
822     if (to_device) {
823         len = MIN(s->async_len, ESP_FIFO_SZ);
824         len = MIN(len, fifo8_num_used(&s->fifo));
825         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
826         s->async_buf += len;
827         s->async_len -= len;
828         s->ti_size += len;
829     } else {
830         if (fifo8_is_empty(&s->fifo)) {
831             fifo8_push(&s->fifo, s->async_buf[0]);
832             s->async_buf++;
833             s->async_len--;
834             s->ti_size--;
835         }
836     }
837 
838     if (s->async_len == 0) {
839         scsi_req_continue(s->current_req);
840         return;
841     }
842 
843     s->rregs[ESP_RINTR] |= INTR_BS;
844     esp_raise_irq(s);
845 }
846 
847 static void esp_pdma_cb(ESPState *s)
848 {
849     switch (s->pdma_cb) {
850     case SATN_PDMA_CB:
851         satn_pdma_cb(s);
852         break;
853     case S_WITHOUT_SATN_PDMA_CB:
854         s_without_satn_pdma_cb(s);
855         break;
856     case SATN_STOP_PDMA_CB:
857         satn_stop_pdma_cb(s);
858         break;
859     case WRITE_RESPONSE_PDMA_CB:
860         write_response_pdma_cb(s);
861         break;
862     case DO_DMA_PDMA_CB:
863         do_dma_pdma_cb(s);
864         break;
865     default:
866         g_assert_not_reached();
867     }
868 }
869 
870 void esp_command_complete(SCSIRequest *req, size_t resid)
871 {
872     ESPState *s = req->hba_private;
873     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
874 
875     trace_esp_command_complete();
876 
877     /*
878      * Non-DMA transfers from the target will leave the last byte in
879      * the FIFO so don't reset ti_size in this case
880      */
881     if (s->dma || to_device) {
882         if (s->ti_size != 0) {
883             trace_esp_command_complete_unexpected();
884         }
885         s->ti_size = 0;
886     }
887 
888     s->async_len = 0;
889     if (req->status) {
890         trace_esp_command_complete_fail();
891     }
892     s->status = req->status;
893 
894     /*
895      * If the transfer is finished, switch to status phase. For non-DMA
896      * transfers from the target the last byte is still in the FIFO
897      */
898     if (s->ti_size == 0) {
899         esp_set_phase(s, STAT_ST);
900         esp_dma_done(s);
901         esp_lower_drq(s);
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     if (s->ti_cmd == 0) {
933         /*
934          * Always perform the initial transfer upon reception of the next TI
935          * command to ensure the DMA/non-DMA status of the command is correct.
936          * It is not possible to use s->dma directly in the section below as
937          * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
938          * async data transfer is delayed then s->dma is set incorrectly.
939          */
940         return;
941     }
942 
943     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
944         if (dmalen) {
945             esp_do_dma(s);
946         } else if (s->ti_size <= 0) {
947             /*
948              * If this was the last part of a DMA transfer then the
949              * completion interrupt is deferred to here.
950              */
951             esp_dma_done(s);
952             esp_lower_drq(s);
953         }
954     } else if (s->ti_cmd == CMD_TI) {
955         esp_do_nodma(s);
956     }
957 }
958 
959 static void handle_ti(ESPState *s)
960 {
961     uint32_t dmalen;
962 
963     if (s->dma && !s->dma_enabled) {
964         s->dma_cb = handle_ti;
965         return;
966     }
967 
968     s->ti_cmd = s->rregs[ESP_CMD];
969     if (s->dma) {
970         dmalen = esp_get_tc(s);
971         trace_esp_handle_ti(dmalen);
972         esp_do_dma(s);
973     } else {
974         trace_esp_handle_ti(s->ti_size);
975         esp_do_nodma(s);
976     }
977 }
978 
979 void esp_hard_reset(ESPState *s)
980 {
981     memset(s->rregs, 0, ESP_REGS);
982     memset(s->wregs, 0, ESP_REGS);
983     s->tchi_written = 0;
984     s->ti_size = 0;
985     s->async_len = 0;
986     fifo8_reset(&s->fifo);
987     fifo8_reset(&s->cmdfifo);
988     s->dma = 0;
989     s->do_cmd = 0;
990     s->dma_cb = NULL;
991 
992     s->rregs[ESP_CFG1] = 7;
993 }
994 
995 static void esp_soft_reset(ESPState *s)
996 {
997     qemu_irq_lower(s->irq);
998     qemu_irq_lower(s->irq_data);
999     esp_hard_reset(s);
1000 }
1001 
1002 static void esp_bus_reset(ESPState *s)
1003 {
1004     bus_cold_reset(BUS(&s->bus));
1005 }
1006 
1007 static void parent_esp_reset(ESPState *s, int irq, int level)
1008 {
1009     if (level) {
1010         esp_soft_reset(s);
1011     }
1012 }
1013 
1014 static void esp_run_cmd(ESPState *s)
1015 {
1016     uint8_t cmd = s->rregs[ESP_CMD];
1017 
1018     if (cmd & CMD_DMA) {
1019         s->dma = 1;
1020         /* Reload DMA counter.  */
1021         if (esp_get_stc(s) == 0) {
1022             esp_set_tc(s, 0x10000);
1023         } else {
1024             esp_set_tc(s, esp_get_stc(s));
1025         }
1026     } else {
1027         s->dma = 0;
1028     }
1029     switch (cmd & CMD_CMD) {
1030     case CMD_NOP:
1031         trace_esp_mem_writeb_cmd_nop(cmd);
1032         break;
1033     case CMD_FLUSH:
1034         trace_esp_mem_writeb_cmd_flush(cmd);
1035         fifo8_reset(&s->fifo);
1036         break;
1037     case CMD_RESET:
1038         trace_esp_mem_writeb_cmd_reset(cmd);
1039         esp_soft_reset(s);
1040         break;
1041     case CMD_BUSRESET:
1042         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1043         esp_bus_reset(s);
1044         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1045             s->rregs[ESP_RINTR] |= INTR_RST;
1046             esp_raise_irq(s);
1047         }
1048         break;
1049     case CMD_TI:
1050         trace_esp_mem_writeb_cmd_ti(cmd);
1051         handle_ti(s);
1052         break;
1053     case CMD_ICCS:
1054         trace_esp_mem_writeb_cmd_iccs(cmd);
1055         write_response(s);
1056         s->rregs[ESP_RINTR] |= INTR_FC;
1057         esp_set_phase(s, STAT_MI);
1058         break;
1059     case CMD_MSGACC:
1060         trace_esp_mem_writeb_cmd_msgacc(cmd);
1061         s->rregs[ESP_RINTR] |= INTR_DC;
1062         s->rregs[ESP_RSEQ] = 0;
1063         s->rregs[ESP_RFLAGS] = 0;
1064         esp_raise_irq(s);
1065         break;
1066     case CMD_PAD:
1067         trace_esp_mem_writeb_cmd_pad(cmd);
1068         s->rregs[ESP_RSTAT] = STAT_TC;
1069         s->rregs[ESP_RINTR] |= INTR_FC;
1070         s->rregs[ESP_RSEQ] = 0;
1071         break;
1072     case CMD_SATN:
1073         trace_esp_mem_writeb_cmd_satn(cmd);
1074         break;
1075     case CMD_RSTATN:
1076         trace_esp_mem_writeb_cmd_rstatn(cmd);
1077         break;
1078     case CMD_SEL:
1079         trace_esp_mem_writeb_cmd_sel(cmd);
1080         handle_s_without_atn(s);
1081         break;
1082     case CMD_SELATN:
1083         trace_esp_mem_writeb_cmd_selatn(cmd);
1084         handle_satn(s);
1085         break;
1086     case CMD_SELATNS:
1087         trace_esp_mem_writeb_cmd_selatns(cmd);
1088         handle_satn_stop(s);
1089         break;
1090     case CMD_ENSEL:
1091         trace_esp_mem_writeb_cmd_ensel(cmd);
1092         s->rregs[ESP_RINTR] = 0;
1093         break;
1094     case CMD_DISSEL:
1095         trace_esp_mem_writeb_cmd_dissel(cmd);
1096         s->rregs[ESP_RINTR] = 0;
1097         esp_raise_irq(s);
1098         break;
1099     default:
1100         trace_esp_error_unhandled_command(cmd);
1101         break;
1102     }
1103 }
1104 
1105 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1106 {
1107     uint32_t val;
1108 
1109     switch (saddr) {
1110     case ESP_FIFO:
1111         if (s->dma_memory_read && s->dma_memory_write &&
1112                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1113             /* Data out.  */
1114             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1115             s->rregs[ESP_FIFO] = 0;
1116         } else {
1117             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1118                 if (s->ti_size) {
1119                     esp_do_nodma(s);
1120                 } else {
1121                     /*
1122                      * The last byte of a non-DMA transfer has been read out
1123                      * of the FIFO so switch to status phase
1124                      */
1125                     esp_set_phase(s, STAT_ST);
1126                 }
1127             }
1128             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1129         }
1130         val = s->rregs[ESP_FIFO];
1131         break;
1132     case ESP_RINTR:
1133         /*
1134          * Clear sequence step, interrupt register and all status bits
1135          * except TC
1136          */
1137         val = s->rregs[ESP_RINTR];
1138         s->rregs[ESP_RINTR] = 0;
1139         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1140         /*
1141          * According to the datasheet ESP_RSEQ should be cleared, but as the
1142          * emulation currently defers information transfers to the next TI
1143          * command leave it for now so that pedantic guests such as the old
1144          * Linux 2.6 driver see the correct flags before the next SCSI phase
1145          * transition.
1146          *
1147          * s->rregs[ESP_RSEQ] = SEQ_0;
1148          */
1149         esp_lower_irq(s);
1150         break;
1151     case ESP_TCHI:
1152         /* Return the unique id if the value has never been written */
1153         if (!s->tchi_written) {
1154             val = s->chip_id;
1155         } else {
1156             val = s->rregs[saddr];
1157         }
1158         break;
1159      case ESP_RFLAGS:
1160         /* Bottom 5 bits indicate number of bytes in FIFO */
1161         val = fifo8_num_used(&s->fifo);
1162         break;
1163     default:
1164         val = s->rregs[saddr];
1165         break;
1166     }
1167 
1168     trace_esp_mem_readb(saddr, val);
1169     return val;
1170 }
1171 
1172 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1173 {
1174     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1175     switch (saddr) {
1176     case ESP_TCHI:
1177         s->tchi_written = true;
1178         /* fall through */
1179     case ESP_TCLO:
1180     case ESP_TCMID:
1181         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1182         break;
1183     case ESP_FIFO:
1184         if (s->do_cmd) {
1185             if (!fifo8_is_full(&s->fifo)) {
1186                 esp_fifo_push(&s->fifo, val);
1187                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1188             }
1189 
1190             /*
1191              * If any unexpected message out/command phase data is
1192              * transferred using non-DMA, raise the interrupt
1193              */
1194             if (s->rregs[ESP_CMD] == CMD_TI) {
1195                 s->rregs[ESP_RINTR] |= INTR_BS;
1196                 esp_raise_irq(s);
1197             }
1198         } else {
1199             esp_fifo_push(&s->fifo, val);
1200         }
1201         break;
1202     case ESP_CMD:
1203         s->rregs[saddr] = val;
1204         esp_run_cmd(s);
1205         break;
1206     case ESP_WBUSID ... ESP_WSYNO:
1207         break;
1208     case ESP_CFG1:
1209     case ESP_CFG2: case ESP_CFG3:
1210     case ESP_RES3: case ESP_RES4:
1211         s->rregs[saddr] = val;
1212         break;
1213     case ESP_WCCF ... ESP_WTEST:
1214         break;
1215     default:
1216         trace_esp_error_invalid_write(val, saddr);
1217         return;
1218     }
1219     s->wregs[saddr] = val;
1220 }
1221 
1222 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1223                             unsigned size, bool is_write,
1224                             MemTxAttrs attrs)
1225 {
1226     return (size == 1) || (is_write && size == 4);
1227 }
1228 
1229 static bool esp_is_before_version_5(void *opaque, int version_id)
1230 {
1231     ESPState *s = ESP(opaque);
1232 
1233     version_id = MIN(version_id, s->mig_version_id);
1234     return version_id < 5;
1235 }
1236 
1237 static bool esp_is_version_5(void *opaque, int version_id)
1238 {
1239     ESPState *s = ESP(opaque);
1240 
1241     version_id = MIN(version_id, s->mig_version_id);
1242     return version_id >= 5;
1243 }
1244 
1245 static bool esp_is_version_6(void *opaque, int version_id)
1246 {
1247     ESPState *s = ESP(opaque);
1248 
1249     version_id = MIN(version_id, s->mig_version_id);
1250     return version_id >= 6;
1251 }
1252 
1253 int esp_pre_save(void *opaque)
1254 {
1255     ESPState *s = ESP(object_resolve_path_component(
1256                       OBJECT(opaque), "esp"));
1257 
1258     s->mig_version_id = vmstate_esp.version_id;
1259     return 0;
1260 }
1261 
1262 static int esp_post_load(void *opaque, int version_id)
1263 {
1264     ESPState *s = ESP(opaque);
1265     int len, i;
1266 
1267     version_id = MIN(version_id, s->mig_version_id);
1268 
1269     if (version_id < 5) {
1270         esp_set_tc(s, s->mig_dma_left);
1271 
1272         /* Migrate ti_buf to fifo */
1273         len = s->mig_ti_wptr - s->mig_ti_rptr;
1274         for (i = 0; i < len; i++) {
1275             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1276         }
1277 
1278         /* Migrate cmdbuf to cmdfifo */
1279         for (i = 0; i < s->mig_cmdlen; i++) {
1280             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1281         }
1282     }
1283 
1284     s->mig_version_id = vmstate_esp.version_id;
1285     return 0;
1286 }
1287 
1288 /*
1289  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1290  * guest CPU to perform the transfers between the SCSI bus and memory
1291  * itself. This is indicated by the dma_memory_read and dma_memory_write
1292  * functions being NULL (in contrast to the ESP PCI device) whilst
1293  * dma_enabled is still set.
1294  */
1295 
1296 static bool esp_pdma_needed(void *opaque)
1297 {
1298     ESPState *s = ESP(opaque);
1299 
1300     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1301            s->dma_enabled;
1302 }
1303 
1304 static const VMStateDescription vmstate_esp_pdma = {
1305     .name = "esp/pdma",
1306     .version_id = 0,
1307     .minimum_version_id = 0,
1308     .needed = esp_pdma_needed,
1309     .fields = (const VMStateField[]) {
1310         VMSTATE_UINT8(pdma_cb, ESPState),
1311         VMSTATE_END_OF_LIST()
1312     }
1313 };
1314 
1315 const VMStateDescription vmstate_esp = {
1316     .name = "esp",
1317     .version_id = 6,
1318     .minimum_version_id = 3,
1319     .post_load = esp_post_load,
1320     .fields = (const VMStateField[]) {
1321         VMSTATE_BUFFER(rregs, ESPState),
1322         VMSTATE_BUFFER(wregs, ESPState),
1323         VMSTATE_INT32(ti_size, ESPState),
1324         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1325         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1326         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1327         VMSTATE_UINT32(status, ESPState),
1328         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1329                             esp_is_before_version_5),
1330         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1331                           esp_is_before_version_5),
1332         VMSTATE_UINT32(dma, ESPState),
1333         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1334                               esp_is_before_version_5, 0, 16),
1335         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1336                               esp_is_before_version_5, 16,
1337                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1338         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1339         VMSTATE_UINT32(do_cmd, ESPState),
1340         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1341         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1342         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1343         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1344         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1345         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1346         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1347         VMSTATE_END_OF_LIST()
1348     },
1349     .subsections = (const VMStateDescription * const []) {
1350         &vmstate_esp_pdma,
1351         NULL
1352     }
1353 };
1354 
1355 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1356                                  uint64_t val, unsigned int size)
1357 {
1358     SysBusESPState *sysbus = opaque;
1359     ESPState *s = ESP(&sysbus->esp);
1360     uint32_t saddr;
1361 
1362     saddr = addr >> sysbus->it_shift;
1363     esp_reg_write(s, saddr, val);
1364 }
1365 
1366 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1367                                     unsigned int size)
1368 {
1369     SysBusESPState *sysbus = opaque;
1370     ESPState *s = ESP(&sysbus->esp);
1371     uint32_t saddr;
1372 
1373     saddr = addr >> sysbus->it_shift;
1374     return esp_reg_read(s, saddr);
1375 }
1376 
1377 static const MemoryRegionOps sysbus_esp_mem_ops = {
1378     .read = sysbus_esp_mem_read,
1379     .write = sysbus_esp_mem_write,
1380     .endianness = DEVICE_NATIVE_ENDIAN,
1381     .valid.accepts = esp_mem_accepts,
1382 };
1383 
1384 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1385                                   uint64_t val, unsigned int size)
1386 {
1387     SysBusESPState *sysbus = opaque;
1388     ESPState *s = ESP(&sysbus->esp);
1389 
1390     trace_esp_pdma_write(size);
1391 
1392     switch (size) {
1393     case 1:
1394         esp_pdma_write(s, val);
1395         break;
1396     case 2:
1397         esp_pdma_write(s, val >> 8);
1398         esp_pdma_write(s, val);
1399         break;
1400     }
1401     esp_pdma_cb(s);
1402 }
1403 
1404 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1405                                      unsigned int size)
1406 {
1407     SysBusESPState *sysbus = opaque;
1408     ESPState *s = ESP(&sysbus->esp);
1409     uint64_t val = 0;
1410 
1411     trace_esp_pdma_read(size);
1412 
1413     switch (size) {
1414     case 1:
1415         val = esp_pdma_read(s);
1416         break;
1417     case 2:
1418         val = esp_pdma_read(s);
1419         val = (val << 8) | esp_pdma_read(s);
1420         break;
1421     }
1422     if (fifo8_num_used(&s->fifo) < 2) {
1423         esp_pdma_cb(s);
1424     }
1425     return val;
1426 }
1427 
1428 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1429 {
1430     ESPState *s = container_of(req->bus, ESPState, bus);
1431 
1432     scsi_req_ref(req);
1433     s->current_req = req;
1434     return s;
1435 }
1436 
1437 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1438     .read = sysbus_esp_pdma_read,
1439     .write = sysbus_esp_pdma_write,
1440     .endianness = DEVICE_NATIVE_ENDIAN,
1441     .valid.min_access_size = 1,
1442     .valid.max_access_size = 4,
1443     .impl.min_access_size = 1,
1444     .impl.max_access_size = 2,
1445 };
1446 
1447 static const struct SCSIBusInfo esp_scsi_info = {
1448     .tcq = false,
1449     .max_target = ESP_MAX_DEVS,
1450     .max_lun = 7,
1451 
1452     .load_request = esp_load_request,
1453     .transfer_data = esp_transfer_data,
1454     .complete = esp_command_complete,
1455     .cancel = esp_request_cancelled
1456 };
1457 
1458 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1459 {
1460     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1461     ESPState *s = ESP(&sysbus->esp);
1462 
1463     switch (irq) {
1464     case 0:
1465         parent_esp_reset(s, irq, level);
1466         break;
1467     case 1:
1468         esp_dma_enable(s, irq, level);
1469         break;
1470     }
1471 }
1472 
1473 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1474 {
1475     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1476     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1477     ESPState *s = ESP(&sysbus->esp);
1478 
1479     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1480         return;
1481     }
1482 
1483     sysbus_init_irq(sbd, &s->irq);
1484     sysbus_init_irq(sbd, &s->irq_data);
1485     assert(sysbus->it_shift != -1);
1486 
1487     s->chip_id = TCHI_FAS100A;
1488     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1489                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1490     sysbus_init_mmio(sbd, &sysbus->iomem);
1491     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1492                           sysbus, "esp-pdma", 4);
1493     sysbus_init_mmio(sbd, &sysbus->pdma);
1494 
1495     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1496 
1497     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1498 }
1499 
1500 static void sysbus_esp_hard_reset(DeviceState *dev)
1501 {
1502     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1503     ESPState *s = ESP(&sysbus->esp);
1504 
1505     esp_hard_reset(s);
1506 }
1507 
1508 static void sysbus_esp_init(Object *obj)
1509 {
1510     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1511 
1512     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1513 }
1514 
1515 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1516     .name = "sysbusespscsi",
1517     .version_id = 2,
1518     .minimum_version_id = 1,
1519     .pre_save = esp_pre_save,
1520     .fields = (const VMStateField[]) {
1521         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1522         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1523         VMSTATE_END_OF_LIST()
1524     }
1525 };
1526 
1527 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1528 {
1529     DeviceClass *dc = DEVICE_CLASS(klass);
1530 
1531     dc->realize = sysbus_esp_realize;
1532     dc->reset = sysbus_esp_hard_reset;
1533     dc->vmsd = &vmstate_sysbus_esp_scsi;
1534     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1535 }
1536 
1537 static const TypeInfo sysbus_esp_info = {
1538     .name          = TYPE_SYSBUS_ESP,
1539     .parent        = TYPE_SYS_BUS_DEVICE,
1540     .instance_init = sysbus_esp_init,
1541     .instance_size = sizeof(SysBusESPState),
1542     .class_init    = sysbus_esp_class_init,
1543 };
1544 
1545 static void esp_finalize(Object *obj)
1546 {
1547     ESPState *s = ESP(obj);
1548 
1549     fifo8_destroy(&s->fifo);
1550     fifo8_destroy(&s->cmdfifo);
1551 }
1552 
1553 static void esp_init(Object *obj)
1554 {
1555     ESPState *s = ESP(obj);
1556 
1557     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1558     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1559 }
1560 
1561 static void esp_class_init(ObjectClass *klass, void *data)
1562 {
1563     DeviceClass *dc = DEVICE_CLASS(klass);
1564 
1565     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1566     dc->user_creatable = false;
1567     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1568 }
1569 
1570 static const TypeInfo esp_info = {
1571     .name = TYPE_ESP,
1572     .parent = TYPE_DEVICE,
1573     .instance_init = esp_init,
1574     .instance_finalize = esp_finalize,
1575     .instance_size = sizeof(ESPState),
1576     .class_init = esp_class_init,
1577 };
1578 
1579 static void esp_register_types(void)
1580 {
1581     type_register_static(&sysbus_esp_info);
1582     type_register_static(&esp_info);
1583 }
1584 
1585 type_init(esp_register_types)
1586