xref: /qemu/hw/scsi/esp.c (revision 942ee6c83fa73e3d6f4b75f382f73b42faaf0559)
1 /*
2  * QEMU ESP/NCR53C9x emulation
3  *
4  * Copyright (c) 2005-2006 Fabrice Bellard
5  * Copyright (c) 2012 Herve Poussineau
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "hw/sysbus.h"
28 #include "migration/vmstate.h"
29 #include "hw/irq.h"
30 #include "hw/scsi/esp.h"
31 #include "trace.h"
32 #include "qemu/log.h"
33 #include "qemu/module.h"
34 
35 /*
36  * On Sparc32, this is the ESP (NCR53C90) part of chip STP2000 (Master I/O),
37  * also produced as NCR89C100. See
38  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
39  * and
40  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR53C9X.txt
41  *
42  * On Macintosh Quadra it is a NCR53C96.
43  */
44 
45 static void esp_raise_irq(ESPState *s)
46 {
47     if (!(s->rregs[ESP_RSTAT] & STAT_INT)) {
48         s->rregs[ESP_RSTAT] |= STAT_INT;
49         qemu_irq_raise(s->irq);
50         trace_esp_raise_irq();
51     }
52 }
53 
54 static void esp_lower_irq(ESPState *s)
55 {
56     if (s->rregs[ESP_RSTAT] & STAT_INT) {
57         s->rregs[ESP_RSTAT] &= ~STAT_INT;
58         qemu_irq_lower(s->irq);
59         trace_esp_lower_irq();
60     }
61 }
62 
63 static void esp_raise_drq(ESPState *s)
64 {
65     qemu_irq_raise(s->irq_data);
66     trace_esp_raise_drq();
67 }
68 
69 static void esp_lower_drq(ESPState *s)
70 {
71     qemu_irq_lower(s->irq_data);
72     trace_esp_lower_drq();
73 }
74 
75 void esp_dma_enable(ESPState *s, int irq, int level)
76 {
77     if (level) {
78         s->dma_enabled = 1;
79         trace_esp_dma_enable();
80         if (s->dma_cb) {
81             s->dma_cb(s);
82             s->dma_cb = NULL;
83         }
84     } else {
85         trace_esp_dma_disable();
86         s->dma_enabled = 0;
87     }
88 }
89 
90 void esp_request_cancelled(SCSIRequest *req)
91 {
92     ESPState *s = req->hba_private;
93 
94     if (req == s->current_req) {
95         scsi_req_unref(s->current_req);
96         s->current_req = NULL;
97         s->current_dev = NULL;
98         s->async_len = 0;
99     }
100 }
101 
102 static void esp_fifo_push(Fifo8 *fifo, uint8_t val)
103 {
104     if (fifo8_num_used(fifo) == fifo->capacity) {
105         trace_esp_error_fifo_overrun();
106         return;
107     }
108 
109     fifo8_push(fifo, val);
110 }
111 
112 static uint8_t esp_fifo_pop(Fifo8 *fifo)
113 {
114     if (fifo8_is_empty(fifo)) {
115         return 0;
116     }
117 
118     return fifo8_pop(fifo);
119 }
120 
121 static uint32_t esp_fifo_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen)
122 {
123     const uint8_t *buf;
124     uint32_t n, n2;
125     int len;
126 
127     if (maxlen == 0) {
128         return 0;
129     }
130 
131     len = maxlen;
132     buf = fifo8_pop_buf(fifo, len, &n);
133     if (dest) {
134         memcpy(dest, buf, n);
135     }
136 
137     /* Add FIFO wraparound if needed */
138     len -= n;
139     len = MIN(len, fifo8_num_used(fifo));
140     if (len) {
141         buf = fifo8_pop_buf(fifo, len, &n2);
142         if (dest) {
143             memcpy(&dest[n], buf, n2);
144         }
145         n += n2;
146     }
147 
148     return n;
149 }
150 
151 static uint32_t esp_get_tc(ESPState *s)
152 {
153     uint32_t dmalen;
154 
155     dmalen = s->rregs[ESP_TCLO];
156     dmalen |= s->rregs[ESP_TCMID] << 8;
157     dmalen |= s->rregs[ESP_TCHI] << 16;
158 
159     return dmalen;
160 }
161 
162 static void esp_set_tc(ESPState *s, uint32_t dmalen)
163 {
164     uint32_t old_tc = esp_get_tc(s);
165 
166     s->rregs[ESP_TCLO] = dmalen;
167     s->rregs[ESP_TCMID] = dmalen >> 8;
168     s->rregs[ESP_TCHI] = dmalen >> 16;
169 
170     if (old_tc && dmalen == 0) {
171         s->rregs[ESP_RSTAT] |= STAT_TC;
172     }
173 }
174 
175 static uint32_t esp_get_stc(ESPState *s)
176 {
177     uint32_t dmalen;
178 
179     dmalen = s->wregs[ESP_TCLO];
180     dmalen |= s->wregs[ESP_TCMID] << 8;
181     dmalen |= s->wregs[ESP_TCHI] << 16;
182 
183     return dmalen;
184 }
185 
186 static const char *esp_phase_names[8] = {
187     "DATA OUT", "DATA IN", "COMMAND", "STATUS",
188     "(reserved)", "(reserved)", "MESSAGE OUT", "MESSAGE IN"
189 };
190 
191 static void esp_set_phase(ESPState *s, uint8_t phase)
192 {
193     s->rregs[ESP_RSTAT] &= ~7;
194     s->rregs[ESP_RSTAT] |= phase;
195 
196     trace_esp_set_phase(esp_phase_names[phase]);
197 }
198 
199 static uint8_t esp_pdma_read(ESPState *s)
200 {
201     uint8_t val;
202 
203     val = esp_fifo_pop(&s->fifo);
204     return val;
205 }
206 
207 static void esp_pdma_write(ESPState *s, uint8_t val)
208 {
209     uint32_t dmalen = esp_get_tc(s);
210 
211     if (dmalen == 0) {
212         return;
213     }
214 
215     esp_fifo_push(&s->fifo, val);
216 
217     dmalen--;
218     esp_set_tc(s, dmalen);
219 }
220 
221 static void esp_set_pdma_cb(ESPState *s, enum pdma_cb cb)
222 {
223     s->pdma_cb = cb;
224 }
225 
226 static int esp_select(ESPState *s)
227 {
228     int target;
229 
230     target = s->wregs[ESP_WBUSID] & BUSID_DID;
231 
232     s->ti_size = 0;
233 
234     if (s->current_req) {
235         /* Started a new command before the old one finished. Cancel it. */
236         scsi_req_cancel(s->current_req);
237     }
238 
239     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
240     if (!s->current_dev) {
241         /* No such drive */
242         s->rregs[ESP_RSTAT] = 0;
243         s->rregs[ESP_RINTR] = INTR_DC;
244         s->rregs[ESP_RSEQ] = SEQ_0;
245         esp_raise_irq(s);
246         return -1;
247     }
248 
249     /*
250      * Note that we deliberately don't raise the IRQ here: this will be done
251      * either in do_command_phase() for DATA OUT transfers or by the deferred
252      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
253      */
254     s->rregs[ESP_RINTR] |= INTR_FC;
255     s->rregs[ESP_RSEQ] = SEQ_CD;
256     return 0;
257 }
258 
259 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
260 {
261     uint8_t buf[ESP_CMDFIFO_SZ];
262     uint32_t dmalen, n;
263     int target;
264 
265     target = s->wregs[ESP_WBUSID] & BUSID_DID;
266     if (s->dma) {
267         dmalen = MIN(esp_get_tc(s), maxlen);
268         if (dmalen == 0) {
269             return 0;
270         }
271         if (s->dma_memory_read) {
272             s->dma_memory_read(s->dma_opaque, buf, dmalen);
273             dmalen = MIN(fifo8_num_free(&s->cmdfifo), dmalen);
274             fifo8_push_all(&s->cmdfifo, buf, dmalen);
275             esp_set_tc(s, esp_get_tc(s) - dmalen);
276         } else {
277             return 0;
278         }
279     } else {
280         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
281         if (dmalen == 0) {
282             return 0;
283         }
284         n = esp_fifo_pop_buf(&s->fifo, buf, dmalen);
285         n = MIN(fifo8_num_free(&s->cmdfifo), n);
286         fifo8_push_all(&s->cmdfifo, buf, n);
287     }
288     trace_esp_get_cmd(dmalen, target);
289 
290     return dmalen;
291 }
292 
293 static void do_command_phase(ESPState *s)
294 {
295     uint32_t cmdlen;
296     int32_t datalen;
297     SCSIDevice *current_lun;
298     uint8_t buf[ESP_CMDFIFO_SZ];
299 
300     trace_esp_do_command_phase(s->lun);
301     cmdlen = fifo8_num_used(&s->cmdfifo);
302     if (!cmdlen || !s->current_dev) {
303         return;
304     }
305     esp_fifo_pop_buf(&s->cmdfifo, buf, cmdlen);
306 
307     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
308     if (!current_lun) {
309         /* No such drive */
310         s->rregs[ESP_RSTAT] = 0;
311         s->rregs[ESP_RINTR] = INTR_DC;
312         s->rregs[ESP_RSEQ] = SEQ_0;
313         esp_raise_irq(s);
314         return;
315     }
316 
317     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
318     datalen = scsi_req_enqueue(s->current_req);
319     s->ti_size = datalen;
320     fifo8_reset(&s->cmdfifo);
321     if (datalen != 0) {
322         s->ti_cmd = 0;
323         if (datalen > 0) {
324             /*
325              * Switch to DATA IN phase but wait until initial data xfer is
326              * complete before raising the command completion interrupt
327              */
328             s->data_in_ready = false;
329             esp_set_phase(s, STAT_DI);
330         } else {
331             esp_set_phase(s, STAT_DO);
332             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
333             esp_raise_irq(s);
334             esp_lower_drq(s);
335         }
336         scsi_req_continue(s->current_req);
337         return;
338     }
339 }
340 
341 static void do_message_phase(ESPState *s)
342 {
343     if (s->cmdfifo_cdb_offset) {
344         uint8_t message = esp_fifo_pop(&s->cmdfifo);
345 
346         trace_esp_do_identify(message);
347         s->lun = message & 7;
348         s->cmdfifo_cdb_offset--;
349     }
350 
351     /* Ignore extended messages for now */
352     if (s->cmdfifo_cdb_offset) {
353         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
354         esp_fifo_pop_buf(&s->cmdfifo, NULL, len);
355         s->cmdfifo_cdb_offset = 0;
356     }
357 }
358 
359 static void do_cmd(ESPState *s)
360 {
361     do_message_phase(s);
362     assert(s->cmdfifo_cdb_offset == 0);
363     do_command_phase(s);
364 }
365 
366 static void satn_pdma_cb(ESPState *s)
367 {
368     uint8_t buf[ESP_FIFO_SZ];
369     int n;
370 
371     /* Copy FIFO into cmdfifo */
372     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
373     n = MIN(fifo8_num_free(&s->cmdfifo), n);
374     fifo8_push_all(&s->cmdfifo, buf, n);
375 
376     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
377         s->cmdfifo_cdb_offset = 1;
378         s->do_cmd = 0;
379         do_cmd(s);
380     }
381 }
382 
383 static void handle_satn(ESPState *s)
384 {
385     int32_t cmdlen;
386 
387     if (s->dma && !s->dma_enabled) {
388         s->dma_cb = handle_satn;
389         return;
390     }
391     esp_set_pdma_cb(s, SATN_PDMA_CB);
392     if (esp_select(s) < 0) {
393         return;
394     }
395     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
396     if (cmdlen > 0) {
397         s->cmdfifo_cdb_offset = 1;
398         s->do_cmd = 0;
399         do_cmd(s);
400     } else if (cmdlen == 0) {
401         if (s->dma) {
402             esp_raise_drq(s);
403         }
404         s->do_cmd = 1;
405         /* Target present, but no cmd yet - switch to command phase */
406         s->rregs[ESP_RSEQ] = SEQ_CD;
407         esp_set_phase(s, STAT_CD);
408     }
409 }
410 
411 static void s_without_satn_pdma_cb(ESPState *s)
412 {
413     uint8_t buf[ESP_FIFO_SZ];
414     int n;
415 
416     /* Copy FIFO into cmdfifo */
417     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
418     n = MIN(fifo8_num_free(&s->cmdfifo), n);
419     fifo8_push_all(&s->cmdfifo, buf, n);
420 
421     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
422         s->cmdfifo_cdb_offset = 0;
423         s->do_cmd = 0;
424         do_cmd(s);
425     }
426 }
427 
428 static void handle_s_without_atn(ESPState *s)
429 {
430     int32_t cmdlen;
431 
432     if (s->dma && !s->dma_enabled) {
433         s->dma_cb = handle_s_without_atn;
434         return;
435     }
436     esp_set_pdma_cb(s, S_WITHOUT_SATN_PDMA_CB);
437     if (esp_select(s) < 0) {
438         return;
439     }
440     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
441     if (cmdlen > 0) {
442         s->cmdfifo_cdb_offset = 0;
443         s->do_cmd = 0;
444         do_cmd(s);
445     } else if (cmdlen == 0) {
446         if (s->dma) {
447             esp_raise_drq(s);
448         }
449         s->do_cmd = 1;
450         /* Target present, but no cmd yet - switch to command phase */
451         s->rregs[ESP_RSEQ] = SEQ_CD;
452         esp_set_phase(s, STAT_CD);
453     }
454 }
455 
456 static void satn_stop_pdma_cb(ESPState *s)
457 {
458     uint8_t buf[ESP_FIFO_SZ];
459     int n;
460 
461     /* Copy FIFO into cmdfifo */
462     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
463     n = MIN(fifo8_num_free(&s->cmdfifo), n);
464     fifo8_push_all(&s->cmdfifo, buf, n);
465 
466     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
467         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
468         s->do_cmd = 1;
469         s->cmdfifo_cdb_offset = 1;
470         esp_set_phase(s, STAT_CD);
471         s->rregs[ESP_RSTAT] |= STAT_TC;
472         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
473         s->rregs[ESP_RSEQ] = SEQ_CD;
474         esp_raise_irq(s);
475     }
476 }
477 
478 static void handle_satn_stop(ESPState *s)
479 {
480     int32_t cmdlen;
481 
482     if (s->dma && !s->dma_enabled) {
483         s->dma_cb = handle_satn_stop;
484         return;
485     }
486     esp_set_pdma_cb(s, SATN_STOP_PDMA_CB);
487     if (esp_select(s) < 0) {
488         return;
489     }
490     cmdlen = get_cmd(s, 1);
491     if (cmdlen > 0) {
492         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
493         s->do_cmd = 1;
494         s->cmdfifo_cdb_offset = 1;
495         esp_set_phase(s, STAT_MO);
496         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
497         s->rregs[ESP_RSEQ] = SEQ_MO;
498         esp_raise_irq(s);
499     } else if (cmdlen == 0) {
500         if (s->dma) {
501             esp_raise_drq(s);
502         }
503         s->do_cmd = 1;
504         /* Target present, switch to message out phase */
505         s->rregs[ESP_RSEQ] = SEQ_MO;
506         esp_set_phase(s, STAT_MO);
507     }
508 }
509 
510 static void write_response_pdma_cb(ESPState *s)
511 {
512     esp_set_phase(s, STAT_ST);
513     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
514     s->rregs[ESP_RSEQ] = SEQ_CD;
515     esp_raise_irq(s);
516 }
517 
518 static void write_response(ESPState *s)
519 {
520     uint8_t buf[2];
521 
522     trace_esp_write_response(s->status);
523 
524     buf[0] = s->status;
525     buf[1] = 0;
526 
527     if (s->dma) {
528         if (s->dma_memory_write) {
529             s->dma_memory_write(s->dma_opaque, buf, 2);
530             esp_set_phase(s, STAT_ST);
531             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
532             s->rregs[ESP_RSEQ] = SEQ_CD;
533         } else {
534             esp_set_pdma_cb(s, WRITE_RESPONSE_PDMA_CB);
535             esp_raise_drq(s);
536             return;
537         }
538     } else {
539         fifo8_reset(&s->fifo);
540         fifo8_push_all(&s->fifo, buf, 2);
541         s->rregs[ESP_RFLAGS] = 2;
542     }
543     esp_raise_irq(s);
544 }
545 
546 static void esp_dma_done(ESPState *s)
547 {
548     s->rregs[ESP_RINTR] |= INTR_BS;
549     esp_raise_irq(s);
550 }
551 
552 static void do_dma_pdma_cb(ESPState *s)
553 {
554     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
555     uint8_t buf[ESP_CMDFIFO_SZ];
556     int len;
557     uint32_t n;
558 
559     if (s->do_cmd) {
560         /* Copy FIFO into cmdfifo */
561         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
562         n = MIN(fifo8_num_free(&s->cmdfifo), n);
563         fifo8_push_all(&s->cmdfifo, buf, n);
564 
565         /* Ensure we have received complete command after SATN and stop */
566         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
567             return;
568         }
569 
570         s->ti_size = 0;
571         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
572             /* No command received */
573             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
574                 return;
575             }
576 
577             /* Command has been received */
578             s->do_cmd = 0;
579             do_cmd(s);
580         } else {
581             /*
582              * Extra message out bytes received: update cmdfifo_cdb_offset
583              * and then switch to command phase
584              */
585             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
586             esp_set_phase(s, STAT_CD);
587             s->rregs[ESP_RSEQ] = SEQ_CD;
588             s->rregs[ESP_RINTR] |= INTR_BS;
589             esp_raise_irq(s);
590         }
591         return;
592     }
593 
594     if (!s->current_req) {
595         return;
596     }
597 
598     if (to_device) {
599         /* Copy FIFO data to device */
600         len = MIN(s->async_len, ESP_FIFO_SZ);
601         len = MIN(len, fifo8_num_used(&s->fifo));
602         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
603         s->async_buf += n;
604         s->async_len -= n;
605         s->ti_size += n;
606 
607         if (n < len) {
608             /* Unaligned accesses can cause FIFO wraparound */
609             len = len - n;
610             n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
611             s->async_buf += n;
612             s->async_len -= n;
613             s->ti_size += n;
614         }
615 
616         if (s->async_len == 0) {
617             scsi_req_continue(s->current_req);
618             return;
619         }
620 
621         if (esp_get_tc(s) == 0) {
622             esp_lower_drq(s);
623             esp_dma_done(s);
624         }
625 
626         return;
627     } else {
628         if (s->async_len == 0) {
629             /* Defer until the scsi layer has completed */
630             scsi_req_continue(s->current_req);
631             s->data_in_ready = false;
632             return;
633         }
634 
635         if (esp_get_tc(s) == 0) {
636             esp_lower_drq(s);
637             esp_dma_done(s);
638         }
639 
640         /* Copy device data to FIFO */
641         len = MIN(s->async_len, esp_get_tc(s));
642         len = MIN(len, fifo8_num_free(&s->fifo));
643         fifo8_push_all(&s->fifo, s->async_buf, len);
644         s->async_buf += len;
645         s->async_len -= len;
646         s->ti_size -= len;
647         esp_set_tc(s, esp_get_tc(s) - len);
648     }
649 }
650 
651 static void esp_do_dma(ESPState *s)
652 {
653     uint32_t len, cmdlen;
654     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
655     uint8_t buf[ESP_CMDFIFO_SZ];
656 
657     len = esp_get_tc(s);
658     if (s->do_cmd) {
659         /*
660          * handle_ti_cmd() case: esp_do_dma() is called only from
661          * handle_ti_cmd() with do_cmd != NULL (see the assert())
662          */
663         cmdlen = fifo8_num_used(&s->cmdfifo);
664         trace_esp_do_dma(cmdlen, len);
665         if (s->dma_memory_read) {
666             len = MIN(len, fifo8_num_free(&s->cmdfifo));
667             s->dma_memory_read(s->dma_opaque, buf, len);
668             fifo8_push_all(&s->cmdfifo, buf, len);
669             esp_set_tc(s, esp_get_tc(s) - len);
670         } else {
671             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
672             esp_raise_drq(s);
673             return;
674         }
675         trace_esp_handle_ti_cmd(cmdlen);
676         s->ti_size = 0;
677         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
678             /* No command received */
679             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
680                 return;
681             }
682 
683             /* Command has been received */
684             s->do_cmd = 0;
685             do_cmd(s);
686         } else {
687             /*
688              * Extra message out bytes received: update cmdfifo_cdb_offset
689              * and then switch to command phase
690              */
691             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
692             esp_set_phase(s, STAT_CD);
693             s->rregs[ESP_RSEQ] = SEQ_CD;
694             s->rregs[ESP_RINTR] |= INTR_BS;
695             esp_raise_irq(s);
696         }
697         return;
698     }
699     if (!s->current_req) {
700         return;
701     }
702     if (s->async_len == 0) {
703         /* Defer until data is available.  */
704         return;
705     }
706     if (len > s->async_len) {
707         len = s->async_len;
708     }
709     if (to_device) {
710         if (s->dma_memory_read) {
711             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
712 
713             esp_set_tc(s, esp_get_tc(s) - len);
714             s->async_buf += len;
715             s->async_len -= len;
716             s->ti_size += len;
717 
718             if (s->async_len == 0) {
719                 scsi_req_continue(s->current_req);
720                 /*
721                  * If there is still data to be read from the device then
722                  * complete the DMA operation immediately.  Otherwise defer
723                  * until the scsi layer has completed.
724                  */
725                 return;
726             }
727 
728             /* Partially filled a scsi buffer. Complete immediately.  */
729             esp_dma_done(s);
730             esp_lower_drq(s);
731         } else {
732             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
733             esp_raise_drq(s);
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) {
745                 scsi_req_continue(s->current_req);
746                 /*
747                  * If there is still data to be read from the device then
748                  * complete the DMA operation immediately.  Otherwise defer
749                  * until the scsi layer has completed.
750                  */
751                 if (esp_get_tc(s) != 0 || s->ti_size == 0) {
752                     return;
753                 }
754             }
755 
756             /* Partially filled a scsi buffer. Complete immediately.  */
757             esp_dma_done(s);
758             esp_lower_drq(s);
759         } else {
760             /* Adjust TC for any leftover data in the FIFO */
761             if (!fifo8_is_empty(&s->fifo)) {
762                 esp_set_tc(s, esp_get_tc(s) - fifo8_num_used(&s->fifo));
763             }
764 
765             /* Copy device data to FIFO */
766             len = MIN(len, fifo8_num_free(&s->fifo));
767             fifo8_push_all(&s->fifo, s->async_buf, len);
768             s->async_buf += len;
769             s->async_len -= len;
770             s->ti_size -= len;
771             esp_set_tc(s, esp_get_tc(s) - len);
772             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
773             esp_raise_drq(s);
774         }
775     }
776 }
777 
778 static void esp_do_nodma(ESPState *s)
779 {
780     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
781     uint8_t buf[ESP_FIFO_SZ];
782     uint32_t cmdlen;
783     int len, n;
784 
785     if (s->do_cmd) {
786         /* Copy FIFO into cmdfifo */
787         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
788         n = MIN(fifo8_num_free(&s->cmdfifo), n);
789         fifo8_push_all(&s->cmdfifo, buf, n);
790 
791         cmdlen = fifo8_num_used(&s->cmdfifo);
792         trace_esp_handle_ti_cmd(cmdlen);
793         s->ti_size = 0;
794         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
795             /* No command received */
796             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
797                 return;
798             }
799 
800             /* Command has been received */
801             s->do_cmd = 0;
802             do_cmd(s);
803         } else {
804             /*
805              * Extra message out bytes received: update cmdfifo_cdb_offset
806              * and then switch to command phase
807              */
808             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
809             esp_set_phase(s, STAT_CD);
810             s->rregs[ESP_RSEQ] = SEQ_CD;
811             s->rregs[ESP_RINTR] |= INTR_BS;
812             esp_raise_irq(s);
813         }
814         return;
815     }
816 
817     if (!s->current_req) {
818         return;
819     }
820 
821     if (s->async_len == 0) {
822         /* Defer until data is available.  */
823         return;
824     }
825 
826     if (to_device) {
827         len = MIN(s->async_len, ESP_FIFO_SZ);
828         len = MIN(len, fifo8_num_used(&s->fifo));
829         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
830         s->async_buf += len;
831         s->async_len -= len;
832         s->ti_size += len;
833     } else {
834         if (fifo8_is_empty(&s->fifo)) {
835             fifo8_push(&s->fifo, s->async_buf[0]);
836             s->async_buf++;
837             s->async_len--;
838             s->ti_size--;
839         }
840     }
841 
842     if (s->async_len == 0) {
843         scsi_req_continue(s->current_req);
844         return;
845     }
846 
847     s->rregs[ESP_RINTR] |= INTR_BS;
848     esp_raise_irq(s);
849 }
850 
851 static void esp_pdma_cb(ESPState *s)
852 {
853     switch (s->pdma_cb) {
854     case SATN_PDMA_CB:
855         satn_pdma_cb(s);
856         break;
857     case S_WITHOUT_SATN_PDMA_CB:
858         s_without_satn_pdma_cb(s);
859         break;
860     case SATN_STOP_PDMA_CB:
861         satn_stop_pdma_cb(s);
862         break;
863     case WRITE_RESPONSE_PDMA_CB:
864         write_response_pdma_cb(s);
865         break;
866     case DO_DMA_PDMA_CB:
867         do_dma_pdma_cb(s);
868         break;
869     default:
870         g_assert_not_reached();
871     }
872 }
873 
874 void esp_command_complete(SCSIRequest *req, size_t resid)
875 {
876     ESPState *s = req->hba_private;
877     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
878 
879     trace_esp_command_complete();
880 
881     /*
882      * Non-DMA transfers from the target will leave the last byte in
883      * the FIFO so don't reset ti_size in this case
884      */
885     if (s->dma || to_device) {
886         if (s->ti_size != 0) {
887             trace_esp_command_complete_unexpected();
888         }
889         s->ti_size = 0;
890     }
891 
892     s->async_len = 0;
893     if (req->status) {
894         trace_esp_command_complete_fail();
895     }
896     s->status = req->status;
897 
898     /*
899      * If the transfer is finished, switch to status phase. For non-DMA
900      * transfers from the target the last byte is still in the FIFO
901      */
902     if (s->ti_size == 0) {
903         esp_set_phase(s, STAT_ST);
904         esp_dma_done(s);
905         esp_lower_drq(s);
906     }
907 
908     if (s->current_req) {
909         scsi_req_unref(s->current_req);
910         s->current_req = NULL;
911         s->current_dev = NULL;
912     }
913 }
914 
915 void esp_transfer_data(SCSIRequest *req, uint32_t len)
916 {
917     ESPState *s = req->hba_private;
918     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
919     uint32_t dmalen = esp_get_tc(s);
920 
921     assert(!s->do_cmd);
922     trace_esp_transfer_data(dmalen, s->ti_size);
923     s->async_len = len;
924     s->async_buf = scsi_req_get_buf(req);
925 
926     if (!to_device && !s->data_in_ready) {
927         /*
928          * Initial incoming data xfer is complete so raise command
929          * completion interrupt
930          */
931         s->data_in_ready = true;
932         s->rregs[ESP_RINTR] |= INTR_BS;
933         esp_raise_irq(s);
934     }
935 
936     if (s->ti_cmd == 0) {
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         return;
945     }
946 
947     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
948         if (dmalen) {
949             esp_do_dma(s);
950         } else if (s->ti_size <= 0) {
951             /*
952              * If this was the last part of a DMA transfer then the
953              * completion interrupt is deferred to here.
954              */
955             esp_dma_done(s);
956             esp_lower_drq(s);
957         }
958     } else if (s->ti_cmd == CMD_TI) {
959         esp_do_nodma(s);
960     }
961 }
962 
963 static void handle_ti(ESPState *s)
964 {
965     uint32_t dmalen;
966 
967     if (s->dma && !s->dma_enabled) {
968         s->dma_cb = handle_ti;
969         return;
970     }
971 
972     s->ti_cmd = s->rregs[ESP_CMD];
973     if (s->dma) {
974         dmalen = esp_get_tc(s);
975         trace_esp_handle_ti(dmalen);
976         esp_do_dma(s);
977     } else {
978         trace_esp_handle_ti(s->ti_size);
979         esp_do_nodma(s);
980     }
981 }
982 
983 void esp_hard_reset(ESPState *s)
984 {
985     memset(s->rregs, 0, ESP_REGS);
986     memset(s->wregs, 0, ESP_REGS);
987     s->tchi_written = 0;
988     s->ti_size = 0;
989     s->async_len = 0;
990     fifo8_reset(&s->fifo);
991     fifo8_reset(&s->cmdfifo);
992     s->dma = 0;
993     s->do_cmd = 0;
994     s->dma_cb = NULL;
995 
996     s->rregs[ESP_CFG1] = 7;
997 }
998 
999 static void esp_soft_reset(ESPState *s)
1000 {
1001     qemu_irq_lower(s->irq);
1002     qemu_irq_lower(s->irq_data);
1003     esp_hard_reset(s);
1004 }
1005 
1006 static void esp_bus_reset(ESPState *s)
1007 {
1008     bus_cold_reset(BUS(&s->bus));
1009 }
1010 
1011 static void parent_esp_reset(ESPState *s, int irq, int level)
1012 {
1013     if (level) {
1014         esp_soft_reset(s);
1015     }
1016 }
1017 
1018 static void esp_run_cmd(ESPState *s)
1019 {
1020     uint8_t cmd = s->rregs[ESP_CMD];
1021 
1022     if (cmd & CMD_DMA) {
1023         s->dma = 1;
1024         /* Reload DMA counter.  */
1025         if (esp_get_stc(s) == 0) {
1026             esp_set_tc(s, 0x10000);
1027         } else {
1028             esp_set_tc(s, esp_get_stc(s));
1029         }
1030     } else {
1031         s->dma = 0;
1032     }
1033     switch (cmd & CMD_CMD) {
1034     case CMD_NOP:
1035         trace_esp_mem_writeb_cmd_nop(cmd);
1036         break;
1037     case CMD_FLUSH:
1038         trace_esp_mem_writeb_cmd_flush(cmd);
1039         fifo8_reset(&s->fifo);
1040         break;
1041     case CMD_RESET:
1042         trace_esp_mem_writeb_cmd_reset(cmd);
1043         esp_soft_reset(s);
1044         break;
1045     case CMD_BUSRESET:
1046         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1047         esp_bus_reset(s);
1048         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1049             s->rregs[ESP_RINTR] |= INTR_RST;
1050             esp_raise_irq(s);
1051         }
1052         break;
1053     case CMD_TI:
1054         trace_esp_mem_writeb_cmd_ti(cmd);
1055         handle_ti(s);
1056         break;
1057     case CMD_ICCS:
1058         trace_esp_mem_writeb_cmd_iccs(cmd);
1059         write_response(s);
1060         s->rregs[ESP_RINTR] |= INTR_FC;
1061         esp_set_phase(s, STAT_MI);
1062         break;
1063     case CMD_MSGACC:
1064         trace_esp_mem_writeb_cmd_msgacc(cmd);
1065         s->rregs[ESP_RINTR] |= INTR_DC;
1066         s->rregs[ESP_RSEQ] = 0;
1067         s->rregs[ESP_RFLAGS] = 0;
1068         esp_raise_irq(s);
1069         break;
1070     case CMD_PAD:
1071         trace_esp_mem_writeb_cmd_pad(cmd);
1072         s->rregs[ESP_RSTAT] = STAT_TC;
1073         s->rregs[ESP_RINTR] |= INTR_FC;
1074         s->rregs[ESP_RSEQ] = 0;
1075         break;
1076     case CMD_SATN:
1077         trace_esp_mem_writeb_cmd_satn(cmd);
1078         break;
1079     case CMD_RSTATN:
1080         trace_esp_mem_writeb_cmd_rstatn(cmd);
1081         break;
1082     case CMD_SEL:
1083         trace_esp_mem_writeb_cmd_sel(cmd);
1084         handle_s_without_atn(s);
1085         break;
1086     case CMD_SELATN:
1087         trace_esp_mem_writeb_cmd_selatn(cmd);
1088         handle_satn(s);
1089         break;
1090     case CMD_SELATNS:
1091         trace_esp_mem_writeb_cmd_selatns(cmd);
1092         handle_satn_stop(s);
1093         break;
1094     case CMD_ENSEL:
1095         trace_esp_mem_writeb_cmd_ensel(cmd);
1096         s->rregs[ESP_RINTR] = 0;
1097         break;
1098     case CMD_DISSEL:
1099         trace_esp_mem_writeb_cmd_dissel(cmd);
1100         s->rregs[ESP_RINTR] = 0;
1101         esp_raise_irq(s);
1102         break;
1103     default:
1104         trace_esp_error_unhandled_command(cmd);
1105         break;
1106     }
1107 }
1108 
1109 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1110 {
1111     uint32_t val;
1112 
1113     switch (saddr) {
1114     case ESP_FIFO:
1115         if (s->dma_memory_read && s->dma_memory_write &&
1116                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1117             /* Data out.  */
1118             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1119             s->rregs[ESP_FIFO] = 0;
1120         } else {
1121             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1122                 if (s->ti_size) {
1123                     esp_do_nodma(s);
1124                 } else {
1125                     /*
1126                      * The last byte of a non-DMA transfer has been read out
1127                      * of the FIFO so switch to status phase
1128                      */
1129                     esp_set_phase(s, STAT_ST);
1130                 }
1131             }
1132             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1133         }
1134         val = s->rregs[ESP_FIFO];
1135         break;
1136     case ESP_RINTR:
1137         /*
1138          * Clear sequence step, interrupt register and all status bits
1139          * except TC
1140          */
1141         val = s->rregs[ESP_RINTR];
1142         s->rregs[ESP_RINTR] = 0;
1143         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1144         /*
1145          * According to the datasheet ESP_RSEQ should be cleared, but as the
1146          * emulation currently defers information transfers to the next TI
1147          * command leave it for now so that pedantic guests such as the old
1148          * Linux 2.6 driver see the correct flags before the next SCSI phase
1149          * transition.
1150          *
1151          * s->rregs[ESP_RSEQ] = SEQ_0;
1152          */
1153         esp_lower_irq(s);
1154         break;
1155     case ESP_TCHI:
1156         /* Return the unique id if the value has never been written */
1157         if (!s->tchi_written) {
1158             val = s->chip_id;
1159         } else {
1160             val = s->rregs[saddr];
1161         }
1162         break;
1163      case ESP_RFLAGS:
1164         /* Bottom 5 bits indicate number of bytes in FIFO */
1165         val = fifo8_num_used(&s->fifo);
1166         break;
1167     default:
1168         val = s->rregs[saddr];
1169         break;
1170     }
1171 
1172     trace_esp_mem_readb(saddr, val);
1173     return val;
1174 }
1175 
1176 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1177 {
1178     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1179     switch (saddr) {
1180     case ESP_TCHI:
1181         s->tchi_written = true;
1182         /* fall through */
1183     case ESP_TCLO:
1184     case ESP_TCMID:
1185         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1186         break;
1187     case ESP_FIFO:
1188         if (s->do_cmd) {
1189             if (!fifo8_is_full(&s->fifo)) {
1190                 esp_fifo_push(&s->fifo, val);
1191                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1192             }
1193 
1194             /*
1195              * If any unexpected message out/command phase data is
1196              * transferred using non-DMA, raise the interrupt
1197              */
1198             if (s->rregs[ESP_CMD] == CMD_TI) {
1199                 s->rregs[ESP_RINTR] |= INTR_BS;
1200                 esp_raise_irq(s);
1201             }
1202         } else {
1203             esp_fifo_push(&s->fifo, val);
1204         }
1205         break;
1206     case ESP_CMD:
1207         s->rregs[saddr] = val;
1208         esp_run_cmd(s);
1209         break;
1210     case ESP_WBUSID ... ESP_WSYNO:
1211         break;
1212     case ESP_CFG1:
1213     case ESP_CFG2: case ESP_CFG3:
1214     case ESP_RES3: case ESP_RES4:
1215         s->rregs[saddr] = val;
1216         break;
1217     case ESP_WCCF ... ESP_WTEST:
1218         break;
1219     default:
1220         trace_esp_error_invalid_write(val, saddr);
1221         return;
1222     }
1223     s->wregs[saddr] = val;
1224 }
1225 
1226 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1227                             unsigned size, bool is_write,
1228                             MemTxAttrs attrs)
1229 {
1230     return (size == 1) || (is_write && size == 4);
1231 }
1232 
1233 static bool esp_is_before_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_5(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 >= 5;
1247 }
1248 
1249 static bool esp_is_version_6(void *opaque, int version_id)
1250 {
1251     ESPState *s = ESP(opaque);
1252 
1253     version_id = MIN(version_id, s->mig_version_id);
1254     return version_id >= 6;
1255 }
1256 
1257 int esp_pre_save(void *opaque)
1258 {
1259     ESPState *s = ESP(object_resolve_path_component(
1260                       OBJECT(opaque), "esp"));
1261 
1262     s->mig_version_id = vmstate_esp.version_id;
1263     return 0;
1264 }
1265 
1266 static int esp_post_load(void *opaque, int version_id)
1267 {
1268     ESPState *s = ESP(opaque);
1269     int len, i;
1270 
1271     version_id = MIN(version_id, s->mig_version_id);
1272 
1273     if (version_id < 5) {
1274         esp_set_tc(s, s->mig_dma_left);
1275 
1276         /* Migrate ti_buf to fifo */
1277         len = s->mig_ti_wptr - s->mig_ti_rptr;
1278         for (i = 0; i < len; i++) {
1279             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1280         }
1281 
1282         /* Migrate cmdbuf to cmdfifo */
1283         for (i = 0; i < s->mig_cmdlen; i++) {
1284             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1285         }
1286     }
1287 
1288     s->mig_version_id = vmstate_esp.version_id;
1289     return 0;
1290 }
1291 
1292 /*
1293  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1294  * guest CPU to perform the transfers between the SCSI bus and memory
1295  * itself. This is indicated by the dma_memory_read and dma_memory_write
1296  * functions being NULL (in contrast to the ESP PCI device) whilst
1297  * dma_enabled is still set.
1298  */
1299 
1300 static bool esp_pdma_needed(void *opaque)
1301 {
1302     ESPState *s = ESP(opaque);
1303 
1304     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1305            s->dma_enabled;
1306 }
1307 
1308 static const VMStateDescription vmstate_esp_pdma = {
1309     .name = "esp/pdma",
1310     .version_id = 0,
1311     .minimum_version_id = 0,
1312     .needed = esp_pdma_needed,
1313     .fields = (const VMStateField[]) {
1314         VMSTATE_UINT8(pdma_cb, ESPState),
1315         VMSTATE_END_OF_LIST()
1316     }
1317 };
1318 
1319 const VMStateDescription vmstate_esp = {
1320     .name = "esp",
1321     .version_id = 6,
1322     .minimum_version_id = 3,
1323     .post_load = esp_post_load,
1324     .fields = (const VMStateField[]) {
1325         VMSTATE_BUFFER(rregs, ESPState),
1326         VMSTATE_BUFFER(wregs, ESPState),
1327         VMSTATE_INT32(ti_size, ESPState),
1328         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1329         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1330         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1331         VMSTATE_UINT32(status, ESPState),
1332         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1333                             esp_is_before_version_5),
1334         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1335                           esp_is_before_version_5),
1336         VMSTATE_UINT32(dma, ESPState),
1337         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1338                               esp_is_before_version_5, 0, 16),
1339         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1340                               esp_is_before_version_5, 16,
1341                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1342         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1343         VMSTATE_UINT32(do_cmd, ESPState),
1344         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1345         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1346         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1347         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1348         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1349         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1350         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1351         VMSTATE_END_OF_LIST()
1352     },
1353     .subsections = (const VMStateDescription * const []) {
1354         &vmstate_esp_pdma,
1355         NULL
1356     }
1357 };
1358 
1359 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1360                                  uint64_t val, unsigned int size)
1361 {
1362     SysBusESPState *sysbus = opaque;
1363     ESPState *s = ESP(&sysbus->esp);
1364     uint32_t saddr;
1365 
1366     saddr = addr >> sysbus->it_shift;
1367     esp_reg_write(s, saddr, val);
1368 }
1369 
1370 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1371                                     unsigned int size)
1372 {
1373     SysBusESPState *sysbus = opaque;
1374     ESPState *s = ESP(&sysbus->esp);
1375     uint32_t saddr;
1376 
1377     saddr = addr >> sysbus->it_shift;
1378     return esp_reg_read(s, saddr);
1379 }
1380 
1381 static const MemoryRegionOps sysbus_esp_mem_ops = {
1382     .read = sysbus_esp_mem_read,
1383     .write = sysbus_esp_mem_write,
1384     .endianness = DEVICE_NATIVE_ENDIAN,
1385     .valid.accepts = esp_mem_accepts,
1386 };
1387 
1388 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1389                                   uint64_t val, unsigned int size)
1390 {
1391     SysBusESPState *sysbus = opaque;
1392     ESPState *s = ESP(&sysbus->esp);
1393 
1394     trace_esp_pdma_write(size);
1395 
1396     switch (size) {
1397     case 1:
1398         esp_pdma_write(s, val);
1399         break;
1400     case 2:
1401         esp_pdma_write(s, val >> 8);
1402         esp_pdma_write(s, val);
1403         break;
1404     }
1405     esp_pdma_cb(s);
1406 }
1407 
1408 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1409                                      unsigned int size)
1410 {
1411     SysBusESPState *sysbus = opaque;
1412     ESPState *s = ESP(&sysbus->esp);
1413     uint64_t val = 0;
1414 
1415     trace_esp_pdma_read(size);
1416 
1417     switch (size) {
1418     case 1:
1419         val = esp_pdma_read(s);
1420         break;
1421     case 2:
1422         val = esp_pdma_read(s);
1423         val = (val << 8) | esp_pdma_read(s);
1424         break;
1425     }
1426     if (fifo8_num_used(&s->fifo) < 2) {
1427         esp_pdma_cb(s);
1428     }
1429     return val;
1430 }
1431 
1432 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1433 {
1434     ESPState *s = container_of(req->bus, ESPState, bus);
1435 
1436     scsi_req_ref(req);
1437     s->current_req = req;
1438     return s;
1439 }
1440 
1441 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1442     .read = sysbus_esp_pdma_read,
1443     .write = sysbus_esp_pdma_write,
1444     .endianness = DEVICE_NATIVE_ENDIAN,
1445     .valid.min_access_size = 1,
1446     .valid.max_access_size = 4,
1447     .impl.min_access_size = 1,
1448     .impl.max_access_size = 2,
1449 };
1450 
1451 static const struct SCSIBusInfo esp_scsi_info = {
1452     .tcq = false,
1453     .max_target = ESP_MAX_DEVS,
1454     .max_lun = 7,
1455 
1456     .load_request = esp_load_request,
1457     .transfer_data = esp_transfer_data,
1458     .complete = esp_command_complete,
1459     .cancel = esp_request_cancelled
1460 };
1461 
1462 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1463 {
1464     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1465     ESPState *s = ESP(&sysbus->esp);
1466 
1467     switch (irq) {
1468     case 0:
1469         parent_esp_reset(s, irq, level);
1470         break;
1471     case 1:
1472         esp_dma_enable(s, irq, level);
1473         break;
1474     }
1475 }
1476 
1477 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1478 {
1479     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1480     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1481     ESPState *s = ESP(&sysbus->esp);
1482 
1483     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1484         return;
1485     }
1486 
1487     sysbus_init_irq(sbd, &s->irq);
1488     sysbus_init_irq(sbd, &s->irq_data);
1489     assert(sysbus->it_shift != -1);
1490 
1491     s->chip_id = TCHI_FAS100A;
1492     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1493                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1494     sysbus_init_mmio(sbd, &sysbus->iomem);
1495     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1496                           sysbus, "esp-pdma", 4);
1497     sysbus_init_mmio(sbd, &sysbus->pdma);
1498 
1499     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1500 
1501     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1502 }
1503 
1504 static void sysbus_esp_hard_reset(DeviceState *dev)
1505 {
1506     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1507     ESPState *s = ESP(&sysbus->esp);
1508 
1509     esp_hard_reset(s);
1510 }
1511 
1512 static void sysbus_esp_init(Object *obj)
1513 {
1514     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1515 
1516     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1517 }
1518 
1519 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1520     .name = "sysbusespscsi",
1521     .version_id = 2,
1522     .minimum_version_id = 1,
1523     .pre_save = esp_pre_save,
1524     .fields = (const VMStateField[]) {
1525         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1526         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1527         VMSTATE_END_OF_LIST()
1528     }
1529 };
1530 
1531 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1532 {
1533     DeviceClass *dc = DEVICE_CLASS(klass);
1534 
1535     dc->realize = sysbus_esp_realize;
1536     dc->reset = sysbus_esp_hard_reset;
1537     dc->vmsd = &vmstate_sysbus_esp_scsi;
1538     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1539 }
1540 
1541 static const TypeInfo sysbus_esp_info = {
1542     .name          = TYPE_SYSBUS_ESP,
1543     .parent        = TYPE_SYS_BUS_DEVICE,
1544     .instance_init = sysbus_esp_init,
1545     .instance_size = sizeof(SysBusESPState),
1546     .class_init    = sysbus_esp_class_init,
1547 };
1548 
1549 static void esp_finalize(Object *obj)
1550 {
1551     ESPState *s = ESP(obj);
1552 
1553     fifo8_destroy(&s->fifo);
1554     fifo8_destroy(&s->cmdfifo);
1555 }
1556 
1557 static void esp_init(Object *obj)
1558 {
1559     ESPState *s = ESP(obj);
1560 
1561     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1562     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1563 }
1564 
1565 static void esp_class_init(ObjectClass *klass, void *data)
1566 {
1567     DeviceClass *dc = DEVICE_CLASS(klass);
1568 
1569     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1570     dc->user_creatable = false;
1571     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1572 }
1573 
1574 static const TypeInfo esp_info = {
1575     .name = TYPE_ESP,
1576     .parent = TYPE_DEVICE,
1577     .instance_init = esp_init,
1578     .instance_finalize = esp_finalize,
1579     .instance_size = sizeof(ESPState),
1580     .class_init = esp_class_init,
1581 };
1582 
1583 static void esp_register_types(void)
1584 {
1585     type_register_static(&sysbus_esp_info);
1586     type_register_static(&esp_info);
1587 }
1588 
1589 type_init(esp_register_types)
1590