xref: /qemu/hw/scsi/esp.c (revision e4e166c8efc13ee8a81e07be2f81f6bc54339a7b)
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 (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
608             /* Defer until the scsi layer has completed */
609             scsi_req_continue(s->current_req);
610             return;
611         }
612 
613         if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
614             esp_lower_drq(s);
615             esp_dma_done(s);
616         }
617 
618         return;
619     } else {
620         if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
621             /* Defer until the scsi layer has completed */
622             scsi_req_continue(s->current_req);
623             s->data_in_ready = false;
624             return;
625         }
626 
627         if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
628             esp_lower_drq(s);
629             esp_dma_done(s);
630         }
631 
632         /* Copy device data to FIFO */
633         len = MIN(s->async_len, esp_get_tc(s));
634         len = MIN(len, fifo8_num_free(&s->fifo));
635         fifo8_push_all(&s->fifo, s->async_buf, len);
636         s->async_buf += len;
637         s->async_len -= len;
638         s->ti_size -= len;
639         esp_set_tc(s, esp_get_tc(s) - len);
640     }
641 }
642 
643 static void esp_do_dma(ESPState *s)
644 {
645     uint32_t len, cmdlen;
646     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
647     uint8_t buf[ESP_CMDFIFO_SZ];
648 
649     len = esp_get_tc(s);
650     if (s->do_cmd) {
651         /*
652          * handle_ti_cmd() case: esp_do_dma() is called only from
653          * handle_ti_cmd() with do_cmd != NULL (see the assert())
654          */
655         cmdlen = fifo8_num_used(&s->cmdfifo);
656         trace_esp_do_dma(cmdlen, len);
657         if (s->dma_memory_read) {
658             len = MIN(len, fifo8_num_free(&s->cmdfifo));
659             s->dma_memory_read(s->dma_opaque, buf, len);
660             fifo8_push_all(&s->cmdfifo, buf, len);
661             esp_set_tc(s, esp_get_tc(s) - len);
662         } else {
663             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
664             esp_raise_drq(s);
665             return;
666         }
667         trace_esp_handle_ti_cmd(cmdlen);
668         s->ti_size = 0;
669         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
670             /* No command received */
671             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
672                 return;
673             }
674 
675             /* Command has been received */
676             s->do_cmd = 0;
677             do_cmd(s);
678         } else {
679             /*
680              * Extra message out bytes received: update cmdfifo_cdb_offset
681              * and then switch to command phase
682              */
683             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
684             esp_set_phase(s, STAT_CD);
685             s->rregs[ESP_RSEQ] = SEQ_CD;
686             s->rregs[ESP_RINTR] |= INTR_BS;
687             esp_raise_irq(s);
688         }
689         return;
690     }
691     if (!s->current_req) {
692         return;
693     }
694     if (s->async_len == 0) {
695         /* Defer until data is available.  */
696         return;
697     }
698     if (len > s->async_len) {
699         len = s->async_len;
700     }
701     if (to_device) {
702         if (s->dma_memory_read) {
703             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
704 
705             esp_set_tc(s, esp_get_tc(s) - len);
706             s->async_buf += len;
707             s->async_len -= len;
708             s->ti_size += len;
709 
710             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
711                 /* Defer until the scsi layer has completed */
712                 scsi_req_continue(s->current_req);
713                 return;
714             }
715 
716             if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
717                 esp_dma_done(s);
718                 esp_lower_drq(s);
719             }
720         } else {
721             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
722             esp_raise_drq(s);
723 
724             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
725                 /* Defer until the scsi layer has completed */
726                 scsi_req_continue(s->current_req);
727                 return;
728             }
729 
730             if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
731                 esp_dma_done(s);
732                 esp_lower_drq(s);
733             }
734         }
735     } else {
736         if (s->dma_memory_write) {
737             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
738 
739             esp_set_tc(s, esp_get_tc(s) - len);
740             s->async_buf += len;
741             s->async_len -= len;
742             s->ti_size -= len;
743 
744             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
745                 /* Defer until the scsi layer has completed */
746                 scsi_req_continue(s->current_req);
747                 return;
748             }
749 
750             if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
751                 esp_dma_done(s);
752                 esp_lower_drq(s);
753             }
754         } else {
755             /* Copy device data to FIFO */
756             len = MIN(len, fifo8_num_free(&s->fifo));
757             fifo8_push_all(&s->fifo, s->async_buf, len);
758             s->async_buf += len;
759             s->async_len -= len;
760             s->ti_size -= len;
761             esp_set_tc(s, esp_get_tc(s) - len);
762             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
763             esp_raise_drq(s);
764 
765             if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
766                 /* Defer until the scsi layer has completed */
767                 scsi_req_continue(s->current_req);
768                 return;
769             }
770 
771             if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
772                 esp_lower_drq(s);
773                 esp_dma_done(s);
774             }
775         }
776     }
777 }
778 
779 static void esp_do_nodma(ESPState *s)
780 {
781     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
782     uint8_t buf[ESP_FIFO_SZ];
783     uint32_t cmdlen;
784     int len, n;
785 
786     if (s->do_cmd) {
787         /* Copy FIFO into cmdfifo */
788         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
789         n = MIN(fifo8_num_free(&s->cmdfifo), n);
790         fifo8_push_all(&s->cmdfifo, buf, n);
791 
792         cmdlen = fifo8_num_used(&s->cmdfifo);
793         trace_esp_handle_ti_cmd(cmdlen);
794         s->ti_size = 0;
795         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
796             /* No command received */
797             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
798                 return;
799             }
800 
801             /* Command has been received */
802             s->do_cmd = 0;
803             do_cmd(s);
804         } else {
805             /*
806              * Extra message out bytes received: update cmdfifo_cdb_offset
807              * and then switch to command phase
808              */
809             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
810             esp_set_phase(s, STAT_CD);
811             s->rregs[ESP_RSEQ] = SEQ_CD;
812             s->rregs[ESP_RINTR] |= INTR_BS;
813             esp_raise_irq(s);
814         }
815         return;
816     }
817 
818     if (!s->current_req) {
819         return;
820     }
821 
822     if (s->async_len == 0) {
823         /* Defer until data is available.  */
824         return;
825     }
826 
827     if (to_device) {
828         len = MIN(s->async_len, ESP_FIFO_SZ);
829         len = MIN(len, fifo8_num_used(&s->fifo));
830         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
831         s->async_buf += len;
832         s->async_len -= len;
833         s->ti_size += len;
834     } else {
835         if (fifo8_is_empty(&s->fifo)) {
836             fifo8_push(&s->fifo, s->async_buf[0]);
837             s->async_buf++;
838             s->async_len--;
839             s->ti_size--;
840         }
841     }
842 
843     if (s->async_len == 0) {
844         scsi_req_continue(s->current_req);
845         return;
846     }
847 
848     s->rregs[ESP_RINTR] |= INTR_BS;
849     esp_raise_irq(s);
850 }
851 
852 static void esp_pdma_cb(ESPState *s)
853 {
854     switch (s->pdma_cb) {
855     case SATN_PDMA_CB:
856         satn_pdma_cb(s);
857         break;
858     case S_WITHOUT_SATN_PDMA_CB:
859         s_without_satn_pdma_cb(s);
860         break;
861     case SATN_STOP_PDMA_CB:
862         satn_stop_pdma_cb(s);
863         break;
864     case WRITE_RESPONSE_PDMA_CB:
865         write_response_pdma_cb(s);
866         break;
867     case DO_DMA_PDMA_CB:
868         do_dma_pdma_cb(s);
869         break;
870     default:
871         g_assert_not_reached();
872     }
873 }
874 
875 void esp_command_complete(SCSIRequest *req, size_t resid)
876 {
877     ESPState *s = req->hba_private;
878     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
879 
880     trace_esp_command_complete();
881 
882     /*
883      * Non-DMA transfers from the target will leave the last byte in
884      * the FIFO so don't reset ti_size in this case
885      */
886     if (s->dma || to_device) {
887         if (s->ti_size != 0) {
888             trace_esp_command_complete_unexpected();
889         }
890         s->ti_size = 0;
891     }
892 
893     s->async_len = 0;
894     if (req->status) {
895         trace_esp_command_complete_fail();
896     }
897     s->status = req->status;
898 
899     /*
900      * If the transfer is finished, switch to status phase. For non-DMA
901      * transfers from the target the last byte is still in the FIFO
902      */
903     if (s->ti_size == 0) {
904         esp_set_phase(s, STAT_ST);
905         esp_dma_done(s);
906         esp_lower_drq(s);
907     }
908 
909     if (s->current_req) {
910         scsi_req_unref(s->current_req);
911         s->current_req = NULL;
912         s->current_dev = NULL;
913     }
914 }
915 
916 void esp_transfer_data(SCSIRequest *req, uint32_t len)
917 {
918     ESPState *s = req->hba_private;
919     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
920     uint32_t dmalen = esp_get_tc(s);
921 
922     assert(!s->do_cmd);
923     trace_esp_transfer_data(dmalen, s->ti_size);
924     s->async_len = len;
925     s->async_buf = scsi_req_get_buf(req);
926 
927     if (!to_device && !s->data_in_ready) {
928         /*
929          * Initial incoming data xfer is complete so raise command
930          * completion interrupt
931          */
932         s->data_in_ready = true;
933         s->rregs[ESP_RINTR] |= INTR_BS;
934         esp_raise_irq(s);
935     }
936 
937     /*
938      * Always perform the initial transfer upon reception of the next TI
939      * command to ensure the DMA/non-DMA status of the command is correct.
940      * It is not possible to use s->dma directly in the section below as
941      * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
942      * async data transfer is delayed then s->dma is set incorrectly.
943      */
944 
945     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
946         /* When the SCSI layer returns more data, raise deferred INTR_BS */
947         esp_dma_done(s);
948 
949         esp_do_dma(s);
950     } else if (s->ti_cmd == CMD_TI) {
951         esp_do_nodma(s);
952     }
953 }
954 
955 static void handle_ti(ESPState *s)
956 {
957     uint32_t dmalen;
958 
959     if (s->dma && !s->dma_enabled) {
960         s->dma_cb = handle_ti;
961         return;
962     }
963 
964     s->ti_cmd = s->rregs[ESP_CMD];
965     if (s->dma) {
966         dmalen = esp_get_tc(s);
967         trace_esp_handle_ti(dmalen);
968         esp_do_dma(s);
969     } else {
970         trace_esp_handle_ti(s->ti_size);
971         esp_do_nodma(s);
972     }
973 }
974 
975 void esp_hard_reset(ESPState *s)
976 {
977     memset(s->rregs, 0, ESP_REGS);
978     memset(s->wregs, 0, ESP_REGS);
979     s->tchi_written = 0;
980     s->ti_size = 0;
981     s->async_len = 0;
982     fifo8_reset(&s->fifo);
983     fifo8_reset(&s->cmdfifo);
984     s->dma = 0;
985     s->do_cmd = 0;
986     s->dma_cb = NULL;
987 
988     s->rregs[ESP_CFG1] = 7;
989 }
990 
991 static void esp_soft_reset(ESPState *s)
992 {
993     qemu_irq_lower(s->irq);
994     qemu_irq_lower(s->irq_data);
995     esp_hard_reset(s);
996 }
997 
998 static void esp_bus_reset(ESPState *s)
999 {
1000     bus_cold_reset(BUS(&s->bus));
1001 }
1002 
1003 static void parent_esp_reset(ESPState *s, int irq, int level)
1004 {
1005     if (level) {
1006         esp_soft_reset(s);
1007     }
1008 }
1009 
1010 static void esp_run_cmd(ESPState *s)
1011 {
1012     uint8_t cmd = s->rregs[ESP_CMD];
1013 
1014     if (cmd & CMD_DMA) {
1015         s->dma = 1;
1016         /* Reload DMA counter.  */
1017         if (esp_get_stc(s) == 0) {
1018             esp_set_tc(s, 0x10000);
1019         } else {
1020             esp_set_tc(s, esp_get_stc(s));
1021         }
1022     } else {
1023         s->dma = 0;
1024     }
1025     switch (cmd & CMD_CMD) {
1026     case CMD_NOP:
1027         trace_esp_mem_writeb_cmd_nop(cmd);
1028         break;
1029     case CMD_FLUSH:
1030         trace_esp_mem_writeb_cmd_flush(cmd);
1031         fifo8_reset(&s->fifo);
1032         break;
1033     case CMD_RESET:
1034         trace_esp_mem_writeb_cmd_reset(cmd);
1035         esp_soft_reset(s);
1036         break;
1037     case CMD_BUSRESET:
1038         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1039         esp_bus_reset(s);
1040         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1041             s->rregs[ESP_RINTR] |= INTR_RST;
1042             esp_raise_irq(s);
1043         }
1044         break;
1045     case CMD_TI:
1046         trace_esp_mem_writeb_cmd_ti(cmd);
1047         handle_ti(s);
1048         break;
1049     case CMD_ICCS:
1050         trace_esp_mem_writeb_cmd_iccs(cmd);
1051         write_response(s);
1052         s->rregs[ESP_RINTR] |= INTR_FC;
1053         esp_set_phase(s, STAT_MI);
1054         break;
1055     case CMD_MSGACC:
1056         trace_esp_mem_writeb_cmd_msgacc(cmd);
1057         s->rregs[ESP_RINTR] |= INTR_DC;
1058         s->rregs[ESP_RSEQ] = 0;
1059         s->rregs[ESP_RFLAGS] = 0;
1060         esp_raise_irq(s);
1061         break;
1062     case CMD_PAD:
1063         trace_esp_mem_writeb_cmd_pad(cmd);
1064         s->rregs[ESP_RSTAT] = STAT_TC;
1065         s->rregs[ESP_RINTR] |= INTR_FC;
1066         s->rregs[ESP_RSEQ] = 0;
1067         break;
1068     case CMD_SATN:
1069         trace_esp_mem_writeb_cmd_satn(cmd);
1070         break;
1071     case CMD_RSTATN:
1072         trace_esp_mem_writeb_cmd_rstatn(cmd);
1073         break;
1074     case CMD_SEL:
1075         trace_esp_mem_writeb_cmd_sel(cmd);
1076         handle_s_without_atn(s);
1077         break;
1078     case CMD_SELATN:
1079         trace_esp_mem_writeb_cmd_selatn(cmd);
1080         handle_satn(s);
1081         break;
1082     case CMD_SELATNS:
1083         trace_esp_mem_writeb_cmd_selatns(cmd);
1084         handle_satn_stop(s);
1085         break;
1086     case CMD_ENSEL:
1087         trace_esp_mem_writeb_cmd_ensel(cmd);
1088         s->rregs[ESP_RINTR] = 0;
1089         break;
1090     case CMD_DISSEL:
1091         trace_esp_mem_writeb_cmd_dissel(cmd);
1092         s->rregs[ESP_RINTR] = 0;
1093         esp_raise_irq(s);
1094         break;
1095     default:
1096         trace_esp_error_unhandled_command(cmd);
1097         break;
1098     }
1099 }
1100 
1101 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1102 {
1103     uint32_t val;
1104 
1105     switch (saddr) {
1106     case ESP_FIFO:
1107         if (s->dma_memory_read && s->dma_memory_write &&
1108                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1109             /* Data out.  */
1110             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1111             s->rregs[ESP_FIFO] = 0;
1112         } else {
1113             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1114                 if (s->ti_size) {
1115                     esp_do_nodma(s);
1116                 } else {
1117                     /*
1118                      * The last byte of a non-DMA transfer has been read out
1119                      * of the FIFO so switch to status phase
1120                      */
1121                     esp_set_phase(s, STAT_ST);
1122                 }
1123             }
1124             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1125         }
1126         val = s->rregs[ESP_FIFO];
1127         break;
1128     case ESP_RINTR:
1129         /*
1130          * Clear sequence step, interrupt register and all status bits
1131          * except TC
1132          */
1133         val = s->rregs[ESP_RINTR];
1134         s->rregs[ESP_RINTR] = 0;
1135         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1136         /*
1137          * According to the datasheet ESP_RSEQ should be cleared, but as the
1138          * emulation currently defers information transfers to the next TI
1139          * command leave it for now so that pedantic guests such as the old
1140          * Linux 2.6 driver see the correct flags before the next SCSI phase
1141          * transition.
1142          *
1143          * s->rregs[ESP_RSEQ] = SEQ_0;
1144          */
1145         esp_lower_irq(s);
1146         break;
1147     case ESP_TCHI:
1148         /* Return the unique id if the value has never been written */
1149         if (!s->tchi_written) {
1150             val = s->chip_id;
1151         } else {
1152             val = s->rregs[saddr];
1153         }
1154         break;
1155      case ESP_RFLAGS:
1156         /* Bottom 5 bits indicate number of bytes in FIFO */
1157         val = fifo8_num_used(&s->fifo);
1158         break;
1159     default:
1160         val = s->rregs[saddr];
1161         break;
1162     }
1163 
1164     trace_esp_mem_readb(saddr, val);
1165     return val;
1166 }
1167 
1168 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1169 {
1170     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1171     switch (saddr) {
1172     case ESP_TCHI:
1173         s->tchi_written = true;
1174         /* fall through */
1175     case ESP_TCLO:
1176     case ESP_TCMID:
1177         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1178         break;
1179     case ESP_FIFO:
1180         if (s->do_cmd) {
1181             if (!fifo8_is_full(&s->fifo)) {
1182                 esp_fifo_push(&s->fifo, val);
1183                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1184             }
1185 
1186             /*
1187              * If any unexpected message out/command phase data is
1188              * transferred using non-DMA, raise the interrupt
1189              */
1190             if (s->rregs[ESP_CMD] == CMD_TI) {
1191                 s->rregs[ESP_RINTR] |= INTR_BS;
1192                 esp_raise_irq(s);
1193             }
1194         } else {
1195             esp_fifo_push(&s->fifo, val);
1196         }
1197         break;
1198     case ESP_CMD:
1199         s->rregs[saddr] = val;
1200         esp_run_cmd(s);
1201         break;
1202     case ESP_WBUSID ... ESP_WSYNO:
1203         break;
1204     case ESP_CFG1:
1205     case ESP_CFG2: case ESP_CFG3:
1206     case ESP_RES3: case ESP_RES4:
1207         s->rregs[saddr] = val;
1208         break;
1209     case ESP_WCCF ... ESP_WTEST:
1210         break;
1211     default:
1212         trace_esp_error_invalid_write(val, saddr);
1213         return;
1214     }
1215     s->wregs[saddr] = val;
1216 }
1217 
1218 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1219                             unsigned size, bool is_write,
1220                             MemTxAttrs attrs)
1221 {
1222     return (size == 1) || (is_write && size == 4);
1223 }
1224 
1225 static bool esp_is_before_version_5(void *opaque, int version_id)
1226 {
1227     ESPState *s = ESP(opaque);
1228 
1229     version_id = MIN(version_id, s->mig_version_id);
1230     return version_id < 5;
1231 }
1232 
1233 static bool esp_is_version_5(void *opaque, int version_id)
1234 {
1235     ESPState *s = ESP(opaque);
1236 
1237     version_id = MIN(version_id, s->mig_version_id);
1238     return version_id >= 5;
1239 }
1240 
1241 static bool esp_is_version_6(void *opaque, int version_id)
1242 {
1243     ESPState *s = ESP(opaque);
1244 
1245     version_id = MIN(version_id, s->mig_version_id);
1246     return version_id >= 6;
1247 }
1248 
1249 int esp_pre_save(void *opaque)
1250 {
1251     ESPState *s = ESP(object_resolve_path_component(
1252                       OBJECT(opaque), "esp"));
1253 
1254     s->mig_version_id = vmstate_esp.version_id;
1255     return 0;
1256 }
1257 
1258 static int esp_post_load(void *opaque, int version_id)
1259 {
1260     ESPState *s = ESP(opaque);
1261     int len, i;
1262 
1263     version_id = MIN(version_id, s->mig_version_id);
1264 
1265     if (version_id < 5) {
1266         esp_set_tc(s, s->mig_dma_left);
1267 
1268         /* Migrate ti_buf to fifo */
1269         len = s->mig_ti_wptr - s->mig_ti_rptr;
1270         for (i = 0; i < len; i++) {
1271             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1272         }
1273 
1274         /* Migrate cmdbuf to cmdfifo */
1275         for (i = 0; i < s->mig_cmdlen; i++) {
1276             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1277         }
1278     }
1279 
1280     s->mig_version_id = vmstate_esp.version_id;
1281     return 0;
1282 }
1283 
1284 /*
1285  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1286  * guest CPU to perform the transfers between the SCSI bus and memory
1287  * itself. This is indicated by the dma_memory_read and dma_memory_write
1288  * functions being NULL (in contrast to the ESP PCI device) whilst
1289  * dma_enabled is still set.
1290  */
1291 
1292 static bool esp_pdma_needed(void *opaque)
1293 {
1294     ESPState *s = ESP(opaque);
1295 
1296     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1297            s->dma_enabled;
1298 }
1299 
1300 static const VMStateDescription vmstate_esp_pdma = {
1301     .name = "esp/pdma",
1302     .version_id = 0,
1303     .minimum_version_id = 0,
1304     .needed = esp_pdma_needed,
1305     .fields = (const VMStateField[]) {
1306         VMSTATE_UINT8(pdma_cb, ESPState),
1307         VMSTATE_END_OF_LIST()
1308     }
1309 };
1310 
1311 const VMStateDescription vmstate_esp = {
1312     .name = "esp",
1313     .version_id = 6,
1314     .minimum_version_id = 3,
1315     .post_load = esp_post_load,
1316     .fields = (const VMStateField[]) {
1317         VMSTATE_BUFFER(rregs, ESPState),
1318         VMSTATE_BUFFER(wregs, ESPState),
1319         VMSTATE_INT32(ti_size, ESPState),
1320         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1321         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1322         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1323         VMSTATE_UINT32(status, ESPState),
1324         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1325                             esp_is_before_version_5),
1326         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1327                           esp_is_before_version_5),
1328         VMSTATE_UINT32(dma, ESPState),
1329         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1330                               esp_is_before_version_5, 0, 16),
1331         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1332                               esp_is_before_version_5, 16,
1333                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1334         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1335         VMSTATE_UINT32(do_cmd, ESPState),
1336         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1337         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1338         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1339         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1340         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1341         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1342         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1343         VMSTATE_END_OF_LIST()
1344     },
1345     .subsections = (const VMStateDescription * const []) {
1346         &vmstate_esp_pdma,
1347         NULL
1348     }
1349 };
1350 
1351 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1352                                  uint64_t val, unsigned int size)
1353 {
1354     SysBusESPState *sysbus = opaque;
1355     ESPState *s = ESP(&sysbus->esp);
1356     uint32_t saddr;
1357 
1358     saddr = addr >> sysbus->it_shift;
1359     esp_reg_write(s, saddr, val);
1360 }
1361 
1362 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1363                                     unsigned int size)
1364 {
1365     SysBusESPState *sysbus = opaque;
1366     ESPState *s = ESP(&sysbus->esp);
1367     uint32_t saddr;
1368 
1369     saddr = addr >> sysbus->it_shift;
1370     return esp_reg_read(s, saddr);
1371 }
1372 
1373 static const MemoryRegionOps sysbus_esp_mem_ops = {
1374     .read = sysbus_esp_mem_read,
1375     .write = sysbus_esp_mem_write,
1376     .endianness = DEVICE_NATIVE_ENDIAN,
1377     .valid.accepts = esp_mem_accepts,
1378 };
1379 
1380 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1381                                   uint64_t val, unsigned int size)
1382 {
1383     SysBusESPState *sysbus = opaque;
1384     ESPState *s = ESP(&sysbus->esp);
1385 
1386     trace_esp_pdma_write(size);
1387 
1388     switch (size) {
1389     case 1:
1390         esp_pdma_write(s, val);
1391         break;
1392     case 2:
1393         esp_pdma_write(s, val >> 8);
1394         esp_pdma_write(s, val);
1395         break;
1396     }
1397     esp_pdma_cb(s);
1398 }
1399 
1400 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1401                                      unsigned int size)
1402 {
1403     SysBusESPState *sysbus = opaque;
1404     ESPState *s = ESP(&sysbus->esp);
1405     uint64_t val = 0;
1406 
1407     trace_esp_pdma_read(size);
1408 
1409     switch (size) {
1410     case 1:
1411         val = esp_pdma_read(s);
1412         break;
1413     case 2:
1414         val = esp_pdma_read(s);
1415         val = (val << 8) | esp_pdma_read(s);
1416         break;
1417     }
1418     esp_pdma_cb(s);
1419     return val;
1420 }
1421 
1422 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1423 {
1424     ESPState *s = container_of(req->bus, ESPState, bus);
1425 
1426     scsi_req_ref(req);
1427     s->current_req = req;
1428     return s;
1429 }
1430 
1431 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1432     .read = sysbus_esp_pdma_read,
1433     .write = sysbus_esp_pdma_write,
1434     .endianness = DEVICE_NATIVE_ENDIAN,
1435     .valid.min_access_size = 1,
1436     .valid.max_access_size = 4,
1437     .impl.min_access_size = 1,
1438     .impl.max_access_size = 2,
1439 };
1440 
1441 static const struct SCSIBusInfo esp_scsi_info = {
1442     .tcq = false,
1443     .max_target = ESP_MAX_DEVS,
1444     .max_lun = 7,
1445 
1446     .load_request = esp_load_request,
1447     .transfer_data = esp_transfer_data,
1448     .complete = esp_command_complete,
1449     .cancel = esp_request_cancelled
1450 };
1451 
1452 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1453 {
1454     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1455     ESPState *s = ESP(&sysbus->esp);
1456 
1457     switch (irq) {
1458     case 0:
1459         parent_esp_reset(s, irq, level);
1460         break;
1461     case 1:
1462         esp_dma_enable(s, irq, level);
1463         break;
1464     }
1465 }
1466 
1467 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1468 {
1469     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1470     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1471     ESPState *s = ESP(&sysbus->esp);
1472 
1473     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1474         return;
1475     }
1476 
1477     sysbus_init_irq(sbd, &s->irq);
1478     sysbus_init_irq(sbd, &s->irq_data);
1479     assert(sysbus->it_shift != -1);
1480 
1481     s->chip_id = TCHI_FAS100A;
1482     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1483                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1484     sysbus_init_mmio(sbd, &sysbus->iomem);
1485     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1486                           sysbus, "esp-pdma", 4);
1487     sysbus_init_mmio(sbd, &sysbus->pdma);
1488 
1489     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1490 
1491     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1492 }
1493 
1494 static void sysbus_esp_hard_reset(DeviceState *dev)
1495 {
1496     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1497     ESPState *s = ESP(&sysbus->esp);
1498 
1499     esp_hard_reset(s);
1500 }
1501 
1502 static void sysbus_esp_init(Object *obj)
1503 {
1504     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1505 
1506     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1507 }
1508 
1509 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1510     .name = "sysbusespscsi",
1511     .version_id = 2,
1512     .minimum_version_id = 1,
1513     .pre_save = esp_pre_save,
1514     .fields = (const VMStateField[]) {
1515         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1516         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1517         VMSTATE_END_OF_LIST()
1518     }
1519 };
1520 
1521 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1522 {
1523     DeviceClass *dc = DEVICE_CLASS(klass);
1524 
1525     dc->realize = sysbus_esp_realize;
1526     dc->reset = sysbus_esp_hard_reset;
1527     dc->vmsd = &vmstate_sysbus_esp_scsi;
1528     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1529 }
1530 
1531 static const TypeInfo sysbus_esp_info = {
1532     .name          = TYPE_SYSBUS_ESP,
1533     .parent        = TYPE_SYS_BUS_DEVICE,
1534     .instance_init = sysbus_esp_init,
1535     .instance_size = sizeof(SysBusESPState),
1536     .class_init    = sysbus_esp_class_init,
1537 };
1538 
1539 static void esp_finalize(Object *obj)
1540 {
1541     ESPState *s = ESP(obj);
1542 
1543     fifo8_destroy(&s->fifo);
1544     fifo8_destroy(&s->cmdfifo);
1545 }
1546 
1547 static void esp_init(Object *obj)
1548 {
1549     ESPState *s = ESP(obj);
1550 
1551     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1552     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1553 }
1554 
1555 static void esp_class_init(ObjectClass *klass, void *data)
1556 {
1557     DeviceClass *dc = DEVICE_CLASS(klass);
1558 
1559     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1560     dc->user_creatable = false;
1561     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1562 }
1563 
1564 static const TypeInfo esp_info = {
1565     .name = TYPE_ESP,
1566     .parent = TYPE_DEVICE,
1567     .instance_init = esp_init,
1568     .instance_finalize = esp_finalize,
1569     .instance_size = sizeof(ESPState),
1570     .class_init = esp_class_init,
1571 };
1572 
1573 static void esp_register_types(void)
1574 {
1575     type_register_static(&sysbus_esp_info);
1576     type_register_static(&esp_info);
1577 }
1578 
1579 type_init(esp_register_types)
1580