xref: /qemu/hw/scsi/esp.c (revision fabcba4966f604e4b7f2e6cd21a8bf6e82834c83)
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 && fifo8_num_used(&s->fifo) < 2) {
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 && fifo8_num_used(&s->fifo) < 2) {
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                 return;
749             }
750 
751             if (esp_get_tc(s) == 0) {
752                 /* Partially filled a scsi buffer. Complete immediately.  */
753                 esp_dma_done(s);
754                 esp_lower_drq(s);
755             }
756         } else {
757             /* Adjust TC for any leftover data in the FIFO */
758             if (!fifo8_is_empty(&s->fifo)) {
759                 esp_set_tc(s, esp_get_tc(s) - fifo8_num_used(&s->fifo));
760             }
761 
762             /* Copy device data to FIFO */
763             len = MIN(len, fifo8_num_free(&s->fifo));
764             fifo8_push_all(&s->fifo, s->async_buf, len);
765             s->async_buf += len;
766             s->async_len -= len;
767             s->ti_size -= len;
768             esp_set_tc(s, esp_get_tc(s) - len);
769             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
770             esp_raise_drq(s);
771         }
772     }
773 }
774 
775 static void esp_do_nodma(ESPState *s)
776 {
777     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
778     uint8_t buf[ESP_FIFO_SZ];
779     uint32_t cmdlen;
780     int len, n;
781 
782     if (s->do_cmd) {
783         /* Copy FIFO into cmdfifo */
784         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
785         n = MIN(fifo8_num_free(&s->cmdfifo), n);
786         fifo8_push_all(&s->cmdfifo, buf, n);
787 
788         cmdlen = fifo8_num_used(&s->cmdfifo);
789         trace_esp_handle_ti_cmd(cmdlen);
790         s->ti_size = 0;
791         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
792             /* No command received */
793             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
794                 return;
795             }
796 
797             /* Command has been received */
798             s->do_cmd = 0;
799             do_cmd(s);
800         } else {
801             /*
802              * Extra message out bytes received: update cmdfifo_cdb_offset
803              * and then switch to command phase
804              */
805             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
806             esp_set_phase(s, STAT_CD);
807             s->rregs[ESP_RSEQ] = SEQ_CD;
808             s->rregs[ESP_RINTR] |= INTR_BS;
809             esp_raise_irq(s);
810         }
811         return;
812     }
813 
814     if (!s->current_req) {
815         return;
816     }
817 
818     if (s->async_len == 0) {
819         /* Defer until data is available.  */
820         return;
821     }
822 
823     if (to_device) {
824         len = MIN(s->async_len, ESP_FIFO_SZ);
825         len = MIN(len, fifo8_num_used(&s->fifo));
826         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
827         s->async_buf += len;
828         s->async_len -= len;
829         s->ti_size += len;
830     } else {
831         if (fifo8_is_empty(&s->fifo)) {
832             fifo8_push(&s->fifo, s->async_buf[0]);
833             s->async_buf++;
834             s->async_len--;
835             s->ti_size--;
836         }
837     }
838 
839     if (s->async_len == 0) {
840         scsi_req_continue(s->current_req);
841         return;
842     }
843 
844     s->rregs[ESP_RINTR] |= INTR_BS;
845     esp_raise_irq(s);
846 }
847 
848 static void esp_pdma_cb(ESPState *s)
849 {
850     switch (s->pdma_cb) {
851     case SATN_PDMA_CB:
852         satn_pdma_cb(s);
853         break;
854     case S_WITHOUT_SATN_PDMA_CB:
855         s_without_satn_pdma_cb(s);
856         break;
857     case SATN_STOP_PDMA_CB:
858         satn_stop_pdma_cb(s);
859         break;
860     case WRITE_RESPONSE_PDMA_CB:
861         write_response_pdma_cb(s);
862         break;
863     case DO_DMA_PDMA_CB:
864         do_dma_pdma_cb(s);
865         break;
866     default:
867         g_assert_not_reached();
868     }
869 }
870 
871 void esp_command_complete(SCSIRequest *req, size_t resid)
872 {
873     ESPState *s = req->hba_private;
874     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
875 
876     trace_esp_command_complete();
877 
878     /*
879      * Non-DMA transfers from the target will leave the last byte in
880      * the FIFO so don't reset ti_size in this case
881      */
882     if (s->dma || to_device) {
883         if (s->ti_size != 0) {
884             trace_esp_command_complete_unexpected();
885         }
886         s->ti_size = 0;
887     }
888 
889     s->async_len = 0;
890     if (req->status) {
891         trace_esp_command_complete_fail();
892     }
893     s->status = req->status;
894 
895     /*
896      * If the transfer is finished, switch to status phase. For non-DMA
897      * transfers from the target the last byte is still in the FIFO
898      */
899     if (s->ti_size == 0) {
900         esp_set_phase(s, STAT_ST);
901         esp_dma_done(s);
902         esp_lower_drq(s);
903     }
904 
905     if (s->current_req) {
906         scsi_req_unref(s->current_req);
907         s->current_req = NULL;
908         s->current_dev = NULL;
909     }
910 }
911 
912 void esp_transfer_data(SCSIRequest *req, uint32_t len)
913 {
914     ESPState *s = req->hba_private;
915     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
916     uint32_t dmalen = esp_get_tc(s);
917 
918     assert(!s->do_cmd);
919     trace_esp_transfer_data(dmalen, s->ti_size);
920     s->async_len = len;
921     s->async_buf = scsi_req_get_buf(req);
922 
923     if (!to_device && !s->data_in_ready) {
924         /*
925          * Initial incoming data xfer is complete so raise command
926          * completion interrupt
927          */
928         s->data_in_ready = true;
929         s->rregs[ESP_RINTR] |= INTR_BS;
930         esp_raise_irq(s);
931     }
932 
933     if (s->ti_cmd == 0) {
934         /*
935          * Always perform the initial transfer upon reception of the next TI
936          * command to ensure the DMA/non-DMA status of the command is correct.
937          * It is not possible to use s->dma directly in the section below as
938          * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
939          * async data transfer is delayed then s->dma is set incorrectly.
940          */
941         return;
942     }
943 
944     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
945         if (dmalen) {
946             esp_do_dma(s);
947         } else if (s->ti_size <= 0) {
948             /*
949              * If this was the last part of a DMA transfer then the
950              * completion interrupt is deferred to here.
951              */
952             esp_dma_done(s);
953             esp_lower_drq(s);
954         }
955     } else if (s->ti_cmd == CMD_TI) {
956         esp_do_nodma(s);
957     }
958 }
959 
960 static void handle_ti(ESPState *s)
961 {
962     uint32_t dmalen;
963 
964     if (s->dma && !s->dma_enabled) {
965         s->dma_cb = handle_ti;
966         return;
967     }
968 
969     s->ti_cmd = s->rregs[ESP_CMD];
970     if (s->dma) {
971         dmalen = esp_get_tc(s);
972         trace_esp_handle_ti(dmalen);
973         esp_do_dma(s);
974     } else {
975         trace_esp_handle_ti(s->ti_size);
976         esp_do_nodma(s);
977     }
978 }
979 
980 void esp_hard_reset(ESPState *s)
981 {
982     memset(s->rregs, 0, ESP_REGS);
983     memset(s->wregs, 0, ESP_REGS);
984     s->tchi_written = 0;
985     s->ti_size = 0;
986     s->async_len = 0;
987     fifo8_reset(&s->fifo);
988     fifo8_reset(&s->cmdfifo);
989     s->dma = 0;
990     s->do_cmd = 0;
991     s->dma_cb = NULL;
992 
993     s->rregs[ESP_CFG1] = 7;
994 }
995 
996 static void esp_soft_reset(ESPState *s)
997 {
998     qemu_irq_lower(s->irq);
999     qemu_irq_lower(s->irq_data);
1000     esp_hard_reset(s);
1001 }
1002 
1003 static void esp_bus_reset(ESPState *s)
1004 {
1005     bus_cold_reset(BUS(&s->bus));
1006 }
1007 
1008 static void parent_esp_reset(ESPState *s, int irq, int level)
1009 {
1010     if (level) {
1011         esp_soft_reset(s);
1012     }
1013 }
1014 
1015 static void esp_run_cmd(ESPState *s)
1016 {
1017     uint8_t cmd = s->rregs[ESP_CMD];
1018 
1019     if (cmd & CMD_DMA) {
1020         s->dma = 1;
1021         /* Reload DMA counter.  */
1022         if (esp_get_stc(s) == 0) {
1023             esp_set_tc(s, 0x10000);
1024         } else {
1025             esp_set_tc(s, esp_get_stc(s));
1026         }
1027     } else {
1028         s->dma = 0;
1029     }
1030     switch (cmd & CMD_CMD) {
1031     case CMD_NOP:
1032         trace_esp_mem_writeb_cmd_nop(cmd);
1033         break;
1034     case CMD_FLUSH:
1035         trace_esp_mem_writeb_cmd_flush(cmd);
1036         fifo8_reset(&s->fifo);
1037         break;
1038     case CMD_RESET:
1039         trace_esp_mem_writeb_cmd_reset(cmd);
1040         esp_soft_reset(s);
1041         break;
1042     case CMD_BUSRESET:
1043         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1044         esp_bus_reset(s);
1045         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1046             s->rregs[ESP_RINTR] |= INTR_RST;
1047             esp_raise_irq(s);
1048         }
1049         break;
1050     case CMD_TI:
1051         trace_esp_mem_writeb_cmd_ti(cmd);
1052         handle_ti(s);
1053         break;
1054     case CMD_ICCS:
1055         trace_esp_mem_writeb_cmd_iccs(cmd);
1056         write_response(s);
1057         s->rregs[ESP_RINTR] |= INTR_FC;
1058         esp_set_phase(s, STAT_MI);
1059         break;
1060     case CMD_MSGACC:
1061         trace_esp_mem_writeb_cmd_msgacc(cmd);
1062         s->rregs[ESP_RINTR] |= INTR_DC;
1063         s->rregs[ESP_RSEQ] = 0;
1064         s->rregs[ESP_RFLAGS] = 0;
1065         esp_raise_irq(s);
1066         break;
1067     case CMD_PAD:
1068         trace_esp_mem_writeb_cmd_pad(cmd);
1069         s->rregs[ESP_RSTAT] = STAT_TC;
1070         s->rregs[ESP_RINTR] |= INTR_FC;
1071         s->rregs[ESP_RSEQ] = 0;
1072         break;
1073     case CMD_SATN:
1074         trace_esp_mem_writeb_cmd_satn(cmd);
1075         break;
1076     case CMD_RSTATN:
1077         trace_esp_mem_writeb_cmd_rstatn(cmd);
1078         break;
1079     case CMD_SEL:
1080         trace_esp_mem_writeb_cmd_sel(cmd);
1081         handle_s_without_atn(s);
1082         break;
1083     case CMD_SELATN:
1084         trace_esp_mem_writeb_cmd_selatn(cmd);
1085         handle_satn(s);
1086         break;
1087     case CMD_SELATNS:
1088         trace_esp_mem_writeb_cmd_selatns(cmd);
1089         handle_satn_stop(s);
1090         break;
1091     case CMD_ENSEL:
1092         trace_esp_mem_writeb_cmd_ensel(cmd);
1093         s->rregs[ESP_RINTR] = 0;
1094         break;
1095     case CMD_DISSEL:
1096         trace_esp_mem_writeb_cmd_dissel(cmd);
1097         s->rregs[ESP_RINTR] = 0;
1098         esp_raise_irq(s);
1099         break;
1100     default:
1101         trace_esp_error_unhandled_command(cmd);
1102         break;
1103     }
1104 }
1105 
1106 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1107 {
1108     uint32_t val;
1109 
1110     switch (saddr) {
1111     case ESP_FIFO:
1112         if (s->dma_memory_read && s->dma_memory_write &&
1113                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1114             /* Data out.  */
1115             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1116             s->rregs[ESP_FIFO] = 0;
1117         } else {
1118             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1119                 if (s->ti_size) {
1120                     esp_do_nodma(s);
1121                 } else {
1122                     /*
1123                      * The last byte of a non-DMA transfer has been read out
1124                      * of the FIFO so switch to status phase
1125                      */
1126                     esp_set_phase(s, STAT_ST);
1127                 }
1128             }
1129             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1130         }
1131         val = s->rregs[ESP_FIFO];
1132         break;
1133     case ESP_RINTR:
1134         /*
1135          * Clear sequence step, interrupt register and all status bits
1136          * except TC
1137          */
1138         val = s->rregs[ESP_RINTR];
1139         s->rregs[ESP_RINTR] = 0;
1140         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1141         /*
1142          * According to the datasheet ESP_RSEQ should be cleared, but as the
1143          * emulation currently defers information transfers to the next TI
1144          * command leave it for now so that pedantic guests such as the old
1145          * Linux 2.6 driver see the correct flags before the next SCSI phase
1146          * transition.
1147          *
1148          * s->rregs[ESP_RSEQ] = SEQ_0;
1149          */
1150         esp_lower_irq(s);
1151         break;
1152     case ESP_TCHI:
1153         /* Return the unique id if the value has never been written */
1154         if (!s->tchi_written) {
1155             val = s->chip_id;
1156         } else {
1157             val = s->rregs[saddr];
1158         }
1159         break;
1160      case ESP_RFLAGS:
1161         /* Bottom 5 bits indicate number of bytes in FIFO */
1162         val = fifo8_num_used(&s->fifo);
1163         break;
1164     default:
1165         val = s->rregs[saddr];
1166         break;
1167     }
1168 
1169     trace_esp_mem_readb(saddr, val);
1170     return val;
1171 }
1172 
1173 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1174 {
1175     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1176     switch (saddr) {
1177     case ESP_TCHI:
1178         s->tchi_written = true;
1179         /* fall through */
1180     case ESP_TCLO:
1181     case ESP_TCMID:
1182         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1183         break;
1184     case ESP_FIFO:
1185         if (s->do_cmd) {
1186             if (!fifo8_is_full(&s->fifo)) {
1187                 esp_fifo_push(&s->fifo, val);
1188                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1189             }
1190 
1191             /*
1192              * If any unexpected message out/command phase data is
1193              * transferred using non-DMA, raise the interrupt
1194              */
1195             if (s->rregs[ESP_CMD] == CMD_TI) {
1196                 s->rregs[ESP_RINTR] |= INTR_BS;
1197                 esp_raise_irq(s);
1198             }
1199         } else {
1200             esp_fifo_push(&s->fifo, val);
1201         }
1202         break;
1203     case ESP_CMD:
1204         s->rregs[saddr] = val;
1205         esp_run_cmd(s);
1206         break;
1207     case ESP_WBUSID ... ESP_WSYNO:
1208         break;
1209     case ESP_CFG1:
1210     case ESP_CFG2: case ESP_CFG3:
1211     case ESP_RES3: case ESP_RES4:
1212         s->rregs[saddr] = val;
1213         break;
1214     case ESP_WCCF ... ESP_WTEST:
1215         break;
1216     default:
1217         trace_esp_error_invalid_write(val, saddr);
1218         return;
1219     }
1220     s->wregs[saddr] = val;
1221 }
1222 
1223 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1224                             unsigned size, bool is_write,
1225                             MemTxAttrs attrs)
1226 {
1227     return (size == 1) || (is_write && size == 4);
1228 }
1229 
1230 static bool esp_is_before_version_5(void *opaque, int version_id)
1231 {
1232     ESPState *s = ESP(opaque);
1233 
1234     version_id = MIN(version_id, s->mig_version_id);
1235     return version_id < 5;
1236 }
1237 
1238 static bool esp_is_version_5(void *opaque, int version_id)
1239 {
1240     ESPState *s = ESP(opaque);
1241 
1242     version_id = MIN(version_id, s->mig_version_id);
1243     return version_id >= 5;
1244 }
1245 
1246 static bool esp_is_version_6(void *opaque, int version_id)
1247 {
1248     ESPState *s = ESP(opaque);
1249 
1250     version_id = MIN(version_id, s->mig_version_id);
1251     return version_id >= 6;
1252 }
1253 
1254 int esp_pre_save(void *opaque)
1255 {
1256     ESPState *s = ESP(object_resolve_path_component(
1257                       OBJECT(opaque), "esp"));
1258 
1259     s->mig_version_id = vmstate_esp.version_id;
1260     return 0;
1261 }
1262 
1263 static int esp_post_load(void *opaque, int version_id)
1264 {
1265     ESPState *s = ESP(opaque);
1266     int len, i;
1267 
1268     version_id = MIN(version_id, s->mig_version_id);
1269 
1270     if (version_id < 5) {
1271         esp_set_tc(s, s->mig_dma_left);
1272 
1273         /* Migrate ti_buf to fifo */
1274         len = s->mig_ti_wptr - s->mig_ti_rptr;
1275         for (i = 0; i < len; i++) {
1276             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1277         }
1278 
1279         /* Migrate cmdbuf to cmdfifo */
1280         for (i = 0; i < s->mig_cmdlen; i++) {
1281             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1282         }
1283     }
1284 
1285     s->mig_version_id = vmstate_esp.version_id;
1286     return 0;
1287 }
1288 
1289 /*
1290  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1291  * guest CPU to perform the transfers between the SCSI bus and memory
1292  * itself. This is indicated by the dma_memory_read and dma_memory_write
1293  * functions being NULL (in contrast to the ESP PCI device) whilst
1294  * dma_enabled is still set.
1295  */
1296 
1297 static bool esp_pdma_needed(void *opaque)
1298 {
1299     ESPState *s = ESP(opaque);
1300 
1301     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1302            s->dma_enabled;
1303 }
1304 
1305 static const VMStateDescription vmstate_esp_pdma = {
1306     .name = "esp/pdma",
1307     .version_id = 0,
1308     .minimum_version_id = 0,
1309     .needed = esp_pdma_needed,
1310     .fields = (const VMStateField[]) {
1311         VMSTATE_UINT8(pdma_cb, ESPState),
1312         VMSTATE_END_OF_LIST()
1313     }
1314 };
1315 
1316 const VMStateDescription vmstate_esp = {
1317     .name = "esp",
1318     .version_id = 6,
1319     .minimum_version_id = 3,
1320     .post_load = esp_post_load,
1321     .fields = (const VMStateField[]) {
1322         VMSTATE_BUFFER(rregs, ESPState),
1323         VMSTATE_BUFFER(wregs, ESPState),
1324         VMSTATE_INT32(ti_size, ESPState),
1325         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1326         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1327         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1328         VMSTATE_UINT32(status, ESPState),
1329         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1330                             esp_is_before_version_5),
1331         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1332                           esp_is_before_version_5),
1333         VMSTATE_UINT32(dma, ESPState),
1334         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1335                               esp_is_before_version_5, 0, 16),
1336         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1337                               esp_is_before_version_5, 16,
1338                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1339         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1340         VMSTATE_UINT32(do_cmd, ESPState),
1341         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1342         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1343         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1344         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1345         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1346         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1347         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1348         VMSTATE_END_OF_LIST()
1349     },
1350     .subsections = (const VMStateDescription * const []) {
1351         &vmstate_esp_pdma,
1352         NULL
1353     }
1354 };
1355 
1356 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1357                                  uint64_t val, unsigned int size)
1358 {
1359     SysBusESPState *sysbus = opaque;
1360     ESPState *s = ESP(&sysbus->esp);
1361     uint32_t saddr;
1362 
1363     saddr = addr >> sysbus->it_shift;
1364     esp_reg_write(s, saddr, val);
1365 }
1366 
1367 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1368                                     unsigned int size)
1369 {
1370     SysBusESPState *sysbus = opaque;
1371     ESPState *s = ESP(&sysbus->esp);
1372     uint32_t saddr;
1373 
1374     saddr = addr >> sysbus->it_shift;
1375     return esp_reg_read(s, saddr);
1376 }
1377 
1378 static const MemoryRegionOps sysbus_esp_mem_ops = {
1379     .read = sysbus_esp_mem_read,
1380     .write = sysbus_esp_mem_write,
1381     .endianness = DEVICE_NATIVE_ENDIAN,
1382     .valid.accepts = esp_mem_accepts,
1383 };
1384 
1385 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1386                                   uint64_t val, unsigned int size)
1387 {
1388     SysBusESPState *sysbus = opaque;
1389     ESPState *s = ESP(&sysbus->esp);
1390 
1391     trace_esp_pdma_write(size);
1392 
1393     switch (size) {
1394     case 1:
1395         esp_pdma_write(s, val);
1396         break;
1397     case 2:
1398         esp_pdma_write(s, val >> 8);
1399         esp_pdma_write(s, val);
1400         break;
1401     }
1402     esp_pdma_cb(s);
1403 }
1404 
1405 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1406                                      unsigned int size)
1407 {
1408     SysBusESPState *sysbus = opaque;
1409     ESPState *s = ESP(&sysbus->esp);
1410     uint64_t val = 0;
1411 
1412     trace_esp_pdma_read(size);
1413 
1414     switch (size) {
1415     case 1:
1416         val = esp_pdma_read(s);
1417         break;
1418     case 2:
1419         val = esp_pdma_read(s);
1420         val = (val << 8) | esp_pdma_read(s);
1421         break;
1422     }
1423     esp_pdma_cb(s);
1424     return val;
1425 }
1426 
1427 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1428 {
1429     ESPState *s = container_of(req->bus, ESPState, bus);
1430 
1431     scsi_req_ref(req);
1432     s->current_req = req;
1433     return s;
1434 }
1435 
1436 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1437     .read = sysbus_esp_pdma_read,
1438     .write = sysbus_esp_pdma_write,
1439     .endianness = DEVICE_NATIVE_ENDIAN,
1440     .valid.min_access_size = 1,
1441     .valid.max_access_size = 4,
1442     .impl.min_access_size = 1,
1443     .impl.max_access_size = 2,
1444 };
1445 
1446 static const struct SCSIBusInfo esp_scsi_info = {
1447     .tcq = false,
1448     .max_target = ESP_MAX_DEVS,
1449     .max_lun = 7,
1450 
1451     .load_request = esp_load_request,
1452     .transfer_data = esp_transfer_data,
1453     .complete = esp_command_complete,
1454     .cancel = esp_request_cancelled
1455 };
1456 
1457 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1458 {
1459     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1460     ESPState *s = ESP(&sysbus->esp);
1461 
1462     switch (irq) {
1463     case 0:
1464         parent_esp_reset(s, irq, level);
1465         break;
1466     case 1:
1467         esp_dma_enable(s, irq, level);
1468         break;
1469     }
1470 }
1471 
1472 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1473 {
1474     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1475     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1476     ESPState *s = ESP(&sysbus->esp);
1477 
1478     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1479         return;
1480     }
1481 
1482     sysbus_init_irq(sbd, &s->irq);
1483     sysbus_init_irq(sbd, &s->irq_data);
1484     assert(sysbus->it_shift != -1);
1485 
1486     s->chip_id = TCHI_FAS100A;
1487     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1488                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1489     sysbus_init_mmio(sbd, &sysbus->iomem);
1490     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1491                           sysbus, "esp-pdma", 4);
1492     sysbus_init_mmio(sbd, &sysbus->pdma);
1493 
1494     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1495 
1496     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1497 }
1498 
1499 static void sysbus_esp_hard_reset(DeviceState *dev)
1500 {
1501     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1502     ESPState *s = ESP(&sysbus->esp);
1503 
1504     esp_hard_reset(s);
1505 }
1506 
1507 static void sysbus_esp_init(Object *obj)
1508 {
1509     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1510 
1511     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1512 }
1513 
1514 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1515     .name = "sysbusespscsi",
1516     .version_id = 2,
1517     .minimum_version_id = 1,
1518     .pre_save = esp_pre_save,
1519     .fields = (const VMStateField[]) {
1520         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1521         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1522         VMSTATE_END_OF_LIST()
1523     }
1524 };
1525 
1526 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1527 {
1528     DeviceClass *dc = DEVICE_CLASS(klass);
1529 
1530     dc->realize = sysbus_esp_realize;
1531     dc->reset = sysbus_esp_hard_reset;
1532     dc->vmsd = &vmstate_sysbus_esp_scsi;
1533     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1534 }
1535 
1536 static const TypeInfo sysbus_esp_info = {
1537     .name          = TYPE_SYSBUS_ESP,
1538     .parent        = TYPE_SYS_BUS_DEVICE,
1539     .instance_init = sysbus_esp_init,
1540     .instance_size = sizeof(SysBusESPState),
1541     .class_init    = sysbus_esp_class_init,
1542 };
1543 
1544 static void esp_finalize(Object *obj)
1545 {
1546     ESPState *s = ESP(obj);
1547 
1548     fifo8_destroy(&s->fifo);
1549     fifo8_destroy(&s->cmdfifo);
1550 }
1551 
1552 static void esp_init(Object *obj)
1553 {
1554     ESPState *s = ESP(obj);
1555 
1556     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1557     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1558 }
1559 
1560 static void esp_class_init(ObjectClass *klass, void *data)
1561 {
1562     DeviceClass *dc = DEVICE_CLASS(klass);
1563 
1564     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1565     dc->user_creatable = false;
1566     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1567 }
1568 
1569 static const TypeInfo esp_info = {
1570     .name = TYPE_ESP,
1571     .parent = TYPE_DEVICE,
1572     .instance_init = esp_init,
1573     .instance_finalize = esp_finalize,
1574     .instance_size = sizeof(ESPState),
1575     .class_init = esp_class_init,
1576 };
1577 
1578 static void esp_register_types(void)
1579 {
1580     type_register_static(&sysbus_esp_info);
1581     type_register_static(&esp_info);
1582 }
1583 
1584 type_init(esp_register_types)
1585