xref: /qemu/hw/scsi/esp.c (revision 5fd4de76048966bb3b6c768e6ca5008600ea07d4)
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 uint8_t esp_pdma_read(ESPState *s)
187 {
188     uint8_t val;
189 
190     val = esp_fifo_pop(&s->fifo);
191     return val;
192 }
193 
194 static void esp_pdma_write(ESPState *s, uint8_t val)
195 {
196     uint32_t dmalen = esp_get_tc(s);
197 
198     if (dmalen == 0) {
199         return;
200     }
201 
202     if (s->do_cmd) {
203         esp_fifo_push(&s->cmdfifo, val);
204     } else {
205         esp_fifo_push(&s->fifo, val);
206     }
207 
208     dmalen--;
209     esp_set_tc(s, dmalen);
210 }
211 
212 static void esp_set_pdma_cb(ESPState *s, enum pdma_cb cb)
213 {
214     s->pdma_cb = cb;
215 }
216 
217 static int esp_select(ESPState *s)
218 {
219     int target;
220 
221     target = s->wregs[ESP_WBUSID] & BUSID_DID;
222 
223     s->ti_size = 0;
224 
225     if (s->current_req) {
226         /* Started a new command before the old one finished. Cancel it. */
227         scsi_req_cancel(s->current_req);
228     }
229 
230     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
231     if (!s->current_dev) {
232         /* No such drive */
233         s->rregs[ESP_RSTAT] = 0;
234         s->rregs[ESP_RINTR] = INTR_DC;
235         s->rregs[ESP_RSEQ] = SEQ_0;
236         esp_raise_irq(s);
237         return -1;
238     }
239 
240     /*
241      * Note that we deliberately don't raise the IRQ here: this will be done
242      * either in do_command_phase() for DATA OUT transfers or by the deferred
243      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
244      */
245     s->rregs[ESP_RINTR] |= INTR_FC;
246     s->rregs[ESP_RSEQ] = SEQ_CD;
247     return 0;
248 }
249 
250 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
251 {
252     uint8_t buf[ESP_CMDFIFO_SZ];
253     uint32_t dmalen, n;
254     int target;
255 
256     target = s->wregs[ESP_WBUSID] & BUSID_DID;
257     if (s->dma) {
258         dmalen = MIN(esp_get_tc(s), maxlen);
259         if (dmalen == 0) {
260             return 0;
261         }
262         if (s->dma_memory_read) {
263             s->dma_memory_read(s->dma_opaque, buf, dmalen);
264             dmalen = MIN(fifo8_num_free(&s->cmdfifo), dmalen);
265             fifo8_push_all(&s->cmdfifo, buf, dmalen);
266         } else {
267             return 0;
268         }
269     } else {
270         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
271         if (dmalen == 0) {
272             return 0;
273         }
274         n = esp_fifo_pop_buf(&s->fifo, buf, dmalen);
275         n = MIN(fifo8_num_free(&s->cmdfifo), n);
276         fifo8_push_all(&s->cmdfifo, buf, n);
277     }
278     trace_esp_get_cmd(dmalen, target);
279 
280     return dmalen;
281 }
282 
283 static void do_command_phase(ESPState *s)
284 {
285     uint32_t cmdlen;
286     int32_t datalen;
287     SCSIDevice *current_lun;
288     uint8_t buf[ESP_CMDFIFO_SZ];
289 
290     trace_esp_do_command_phase(s->lun);
291     cmdlen = fifo8_num_used(&s->cmdfifo);
292     if (!cmdlen || !s->current_dev) {
293         return;
294     }
295     esp_fifo_pop_buf(&s->cmdfifo, buf, cmdlen);
296 
297     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
298     if (!current_lun) {
299         /* No such drive */
300         s->rregs[ESP_RSTAT] = 0;
301         s->rregs[ESP_RINTR] = INTR_DC;
302         s->rregs[ESP_RSEQ] = SEQ_0;
303         esp_raise_irq(s);
304         return;
305     }
306 
307     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
308     datalen = scsi_req_enqueue(s->current_req);
309     s->ti_size = datalen;
310     fifo8_reset(&s->cmdfifo);
311     if (datalen != 0) {
312         s->rregs[ESP_RSTAT] = STAT_TC;
313         s->rregs[ESP_RSEQ] = SEQ_CD;
314         s->ti_cmd = 0;
315         esp_set_tc(s, 0);
316         if (datalen > 0) {
317             /*
318              * Switch to DATA IN phase but wait until initial data xfer is
319              * complete before raising the command completion interrupt
320              */
321             s->data_in_ready = false;
322             s->rregs[ESP_RSTAT] |= STAT_DI;
323         } else {
324             s->rregs[ESP_RSTAT] |= STAT_DO;
325             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
326             esp_raise_irq(s);
327             esp_lower_drq(s);
328         }
329         scsi_req_continue(s->current_req);
330         return;
331     }
332 }
333 
334 static void do_message_phase(ESPState *s)
335 {
336     if (s->cmdfifo_cdb_offset) {
337         uint8_t message = esp_fifo_pop(&s->cmdfifo);
338 
339         trace_esp_do_identify(message);
340         s->lun = message & 7;
341         s->cmdfifo_cdb_offset--;
342     }
343 
344     /* Ignore extended messages for now */
345     if (s->cmdfifo_cdb_offset) {
346         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
347         esp_fifo_pop_buf(&s->cmdfifo, NULL, len);
348         s->cmdfifo_cdb_offset = 0;
349     }
350 }
351 
352 static void do_cmd(ESPState *s)
353 {
354     do_message_phase(s);
355     assert(s->cmdfifo_cdb_offset == 0);
356     do_command_phase(s);
357 }
358 
359 static void satn_pdma_cb(ESPState *s)
360 {
361     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
362         s->cmdfifo_cdb_offset = 1;
363         s->do_cmd = 0;
364         do_cmd(s);
365     }
366 }
367 
368 static void handle_satn(ESPState *s)
369 {
370     int32_t cmdlen;
371 
372     if (s->dma && !s->dma_enabled) {
373         s->dma_cb = handle_satn;
374         return;
375     }
376     esp_set_pdma_cb(s, SATN_PDMA_CB);
377     if (esp_select(s) < 0) {
378         return;
379     }
380     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
381     if (cmdlen > 0) {
382         s->cmdfifo_cdb_offset = 1;
383         s->do_cmd = 0;
384         do_cmd(s);
385     } else if (cmdlen == 0) {
386         if (s->dma) {
387             esp_raise_drq(s);
388         }
389         s->do_cmd = 1;
390         /* Target present, but no cmd yet - switch to command phase */
391         s->rregs[ESP_RSEQ] = SEQ_CD;
392         s->rregs[ESP_RSTAT] = STAT_CD;
393     }
394 }
395 
396 static void s_without_satn_pdma_cb(ESPState *s)
397 {
398     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
399         s->cmdfifo_cdb_offset = 0;
400         s->do_cmd = 0;
401         do_cmd(s);
402     }
403 }
404 
405 static void handle_s_without_atn(ESPState *s)
406 {
407     int32_t cmdlen;
408 
409     if (s->dma && !s->dma_enabled) {
410         s->dma_cb = handle_s_without_atn;
411         return;
412     }
413     esp_set_pdma_cb(s, S_WITHOUT_SATN_PDMA_CB);
414     if (esp_select(s) < 0) {
415         return;
416     }
417     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
418     if (cmdlen > 0) {
419         s->cmdfifo_cdb_offset = 0;
420         s->do_cmd = 0;
421         do_cmd(s);
422     } else if (cmdlen == 0) {
423         if (s->dma) {
424             esp_raise_drq(s);
425         }
426         s->do_cmd = 1;
427         /* Target present, but no cmd yet - switch to command phase */
428         s->rregs[ESP_RSEQ] = SEQ_CD;
429         s->rregs[ESP_RSTAT] = STAT_CD;
430     }
431 }
432 
433 static void satn_stop_pdma_cb(ESPState *s)
434 {
435     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
436         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
437         s->do_cmd = 1;
438         s->cmdfifo_cdb_offset = 1;
439         s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
440         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
441         s->rregs[ESP_RSEQ] = SEQ_CD;
442         esp_raise_irq(s);
443     }
444 }
445 
446 static void handle_satn_stop(ESPState *s)
447 {
448     int32_t cmdlen;
449 
450     if (s->dma && !s->dma_enabled) {
451         s->dma_cb = handle_satn_stop;
452         return;
453     }
454     esp_set_pdma_cb(s, SATN_STOP_PDMA_CB);
455     if (esp_select(s) < 0) {
456         return;
457     }
458     cmdlen = get_cmd(s, 1);
459     if (cmdlen > 0) {
460         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
461         s->do_cmd = 1;
462         s->cmdfifo_cdb_offset = 1;
463         s->rregs[ESP_RSTAT] = STAT_MO;
464         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
465         s->rregs[ESP_RSEQ] = SEQ_MO;
466         esp_raise_irq(s);
467     } else if (cmdlen == 0) {
468         if (s->dma) {
469             esp_raise_drq(s);
470         }
471         s->do_cmd = 1;
472         /* Target present, switch to message out phase */
473         s->rregs[ESP_RSEQ] = SEQ_MO;
474         s->rregs[ESP_RSTAT] = STAT_MO;
475     }
476 }
477 
478 static void write_response_pdma_cb(ESPState *s)
479 {
480     s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
481     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
482     s->rregs[ESP_RSEQ] = SEQ_CD;
483     esp_raise_irq(s);
484 }
485 
486 static void write_response(ESPState *s)
487 {
488     uint8_t buf[2];
489 
490     trace_esp_write_response(s->status);
491 
492     buf[0] = s->status;
493     buf[1] = 0;
494 
495     if (s->dma) {
496         if (s->dma_memory_write) {
497             s->dma_memory_write(s->dma_opaque, buf, 2);
498             s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
499             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
500             s->rregs[ESP_RSEQ] = SEQ_CD;
501         } else {
502             esp_set_pdma_cb(s, WRITE_RESPONSE_PDMA_CB);
503             esp_raise_drq(s);
504             return;
505         }
506     } else {
507         fifo8_reset(&s->fifo);
508         fifo8_push_all(&s->fifo, buf, 2);
509         s->rregs[ESP_RFLAGS] = 2;
510     }
511     esp_raise_irq(s);
512 }
513 
514 static void esp_dma_done(ESPState *s)
515 {
516     s->rregs[ESP_RSTAT] |= STAT_TC;
517     s->rregs[ESP_RINTR] |= INTR_BS;
518     s->rregs[ESP_RFLAGS] = 0;
519     esp_set_tc(s, 0);
520     esp_raise_irq(s);
521 }
522 
523 static void do_dma_pdma_cb(ESPState *s)
524 {
525     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
526     int len;
527     uint32_t n;
528 
529     if (s->do_cmd) {
530         /* Ensure we have received complete command after SATN and stop */
531         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
532             return;
533         }
534 
535         s->ti_size = 0;
536         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
537             /* No command received */
538             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
539                 return;
540             }
541 
542             /* Command has been received */
543             s->do_cmd = 0;
544             do_cmd(s);
545         } else {
546             /*
547              * Extra message out bytes received: update cmdfifo_cdb_offset
548              * and then switch to command phase
549              */
550             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
551             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
552             s->rregs[ESP_RSEQ] = SEQ_CD;
553             s->rregs[ESP_RINTR] |= INTR_BS;
554             esp_raise_irq(s);
555         }
556         return;
557     }
558 
559     if (!s->current_req) {
560         return;
561     }
562 
563     if (to_device) {
564         /* Copy FIFO data to device */
565         len = MIN(s->async_len, ESP_FIFO_SZ);
566         len = MIN(len, fifo8_num_used(&s->fifo));
567         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
568         s->async_buf += n;
569         s->async_len -= n;
570         s->ti_size += n;
571 
572         if (n < len) {
573             /* Unaligned accesses can cause FIFO wraparound */
574             len = len - n;
575             n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
576             s->async_buf += n;
577             s->async_len -= n;
578             s->ti_size += n;
579         }
580 
581         if (s->async_len == 0) {
582             scsi_req_continue(s->current_req);
583             return;
584         }
585 
586         if (esp_get_tc(s) == 0) {
587             esp_lower_drq(s);
588             esp_dma_done(s);
589         }
590 
591         return;
592     } else {
593         if (s->async_len == 0) {
594             /* Defer until the scsi layer has completed */
595             scsi_req_continue(s->current_req);
596             s->data_in_ready = false;
597             return;
598         }
599 
600         if (esp_get_tc(s) == 0) {
601             esp_lower_drq(s);
602             esp_dma_done(s);
603         }
604 
605         /* Copy device data to FIFO */
606         len = MIN(s->async_len, esp_get_tc(s));
607         len = MIN(len, fifo8_num_free(&s->fifo));
608         fifo8_push_all(&s->fifo, s->async_buf, len);
609         s->async_buf += len;
610         s->async_len -= len;
611         s->ti_size -= len;
612         esp_set_tc(s, esp_get_tc(s) - len);
613     }
614 }
615 
616 static void esp_do_dma(ESPState *s)
617 {
618     uint32_t len, cmdlen;
619     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
620     uint8_t buf[ESP_CMDFIFO_SZ];
621 
622     len = esp_get_tc(s);
623     if (s->do_cmd) {
624         /*
625          * handle_ti_cmd() case: esp_do_dma() is called only from
626          * handle_ti_cmd() with do_cmd != NULL (see the assert())
627          */
628         cmdlen = fifo8_num_used(&s->cmdfifo);
629         trace_esp_do_dma(cmdlen, len);
630         if (s->dma_memory_read) {
631             len = MIN(len, fifo8_num_free(&s->cmdfifo));
632             s->dma_memory_read(s->dma_opaque, buf, len);
633             fifo8_push_all(&s->cmdfifo, buf, len);
634         } else {
635             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
636             esp_raise_drq(s);
637             return;
638         }
639         trace_esp_handle_ti_cmd(cmdlen);
640         s->ti_size = 0;
641         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
642             /* No command received */
643             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
644                 return;
645             }
646 
647             /* Command has been received */
648             s->do_cmd = 0;
649             do_cmd(s);
650         } else {
651             /*
652              * Extra message out bytes received: update cmdfifo_cdb_offset
653              * and then switch to command phase
654              */
655             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
656             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
657             s->rregs[ESP_RSEQ] = SEQ_CD;
658             s->rregs[ESP_RINTR] |= INTR_BS;
659             esp_raise_irq(s);
660         }
661         return;
662     }
663     if (!s->current_req) {
664         return;
665     }
666     if (s->async_len == 0) {
667         /* Defer until data is available.  */
668         return;
669     }
670     if (len > s->async_len) {
671         len = s->async_len;
672     }
673     if (to_device) {
674         if (s->dma_memory_read) {
675             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
676 
677             esp_set_tc(s, esp_get_tc(s) - len);
678             s->async_buf += len;
679             s->async_len -= len;
680             s->ti_size += len;
681 
682             if (s->async_len == 0) {
683                 scsi_req_continue(s->current_req);
684                 /*
685                  * If there is still data to be read from the device then
686                  * complete the DMA operation immediately.  Otherwise defer
687                  * until the scsi layer has completed.
688                  */
689                 return;
690             }
691 
692             /* Partially filled a scsi buffer. Complete immediately.  */
693             esp_dma_done(s);
694             esp_lower_drq(s);
695         } else {
696             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
697             esp_raise_drq(s);
698         }
699     } else {
700         if (s->dma_memory_write) {
701             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
702 
703             esp_set_tc(s, esp_get_tc(s) - len);
704             s->async_buf += len;
705             s->async_len -= len;
706             s->ti_size -= len;
707 
708             if (s->async_len == 0) {
709                 scsi_req_continue(s->current_req);
710                 /*
711                  * If there is still data to be read from the device then
712                  * complete the DMA operation immediately.  Otherwise defer
713                  * until the scsi layer has completed.
714                  */
715                 if (esp_get_tc(s) != 0 || s->ti_size == 0) {
716                     return;
717                 }
718             }
719 
720             /* Partially filled a scsi buffer. Complete immediately.  */
721             esp_dma_done(s);
722             esp_lower_drq(s);
723         } else {
724             /* Adjust TC for any leftover data in the FIFO */
725             if (!fifo8_is_empty(&s->fifo)) {
726                 esp_set_tc(s, esp_get_tc(s) - fifo8_num_used(&s->fifo));
727             }
728 
729             /* Copy device data to FIFO */
730             len = MIN(len, fifo8_num_free(&s->fifo));
731             fifo8_push_all(&s->fifo, s->async_buf, len);
732             s->async_buf += len;
733             s->async_len -= len;
734             s->ti_size -= len;
735 
736             /*
737              * MacOS toolbox uses a TI length of 16 bytes for all commands, so
738              * commands shorter than this must be padded accordingly
739              */
740             if (len < esp_get_tc(s) && esp_get_tc(s) <= ESP_FIFO_SZ) {
741                 while (fifo8_num_used(&s->fifo) < ESP_FIFO_SZ) {
742                     esp_fifo_push(&s->fifo, 0);
743                     len++;
744                 }
745             }
746 
747             esp_set_tc(s, esp_get_tc(s) - len);
748             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
749             esp_raise_drq(s);
750         }
751     }
752 }
753 
754 static void esp_do_nodma(ESPState *s)
755 {
756     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
757     uint32_t cmdlen;
758     int len;
759 
760     if (s->do_cmd) {
761         cmdlen = fifo8_num_used(&s->cmdfifo);
762         trace_esp_handle_ti_cmd(cmdlen);
763         s->ti_size = 0;
764         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
765             /* No command received */
766             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
767                 return;
768             }
769 
770             /* Command has been received */
771             s->do_cmd = 0;
772             do_cmd(s);
773         } else {
774             /*
775              * Extra message out bytes received: update cmdfifo_cdb_offset
776              * and then switch to command phase
777              */
778             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
779             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
780             s->rregs[ESP_RSEQ] = SEQ_CD;
781             s->rregs[ESP_RINTR] |= INTR_BS;
782             esp_raise_irq(s);
783         }
784         return;
785     }
786 
787     if (!s->current_req) {
788         return;
789     }
790 
791     if (s->async_len == 0) {
792         /* Defer until data is available.  */
793         return;
794     }
795 
796     if (to_device) {
797         len = MIN(s->async_len, ESP_FIFO_SZ);
798         len = MIN(len, fifo8_num_used(&s->fifo));
799         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
800         s->async_buf += len;
801         s->async_len -= len;
802         s->ti_size += len;
803     } else {
804         if (fifo8_is_empty(&s->fifo)) {
805             fifo8_push(&s->fifo, s->async_buf[0]);
806             s->async_buf++;
807             s->async_len--;
808             s->ti_size--;
809         }
810     }
811 
812     if (s->async_len == 0) {
813         scsi_req_continue(s->current_req);
814         return;
815     }
816 
817     s->rregs[ESP_RINTR] |= INTR_BS;
818     esp_raise_irq(s);
819 }
820 
821 static void esp_pdma_cb(ESPState *s)
822 {
823     switch (s->pdma_cb) {
824     case SATN_PDMA_CB:
825         satn_pdma_cb(s);
826         break;
827     case S_WITHOUT_SATN_PDMA_CB:
828         s_without_satn_pdma_cb(s);
829         break;
830     case SATN_STOP_PDMA_CB:
831         satn_stop_pdma_cb(s);
832         break;
833     case WRITE_RESPONSE_PDMA_CB:
834         write_response_pdma_cb(s);
835         break;
836     case DO_DMA_PDMA_CB:
837         do_dma_pdma_cb(s);
838         break;
839     default:
840         g_assert_not_reached();
841     }
842 }
843 
844 void esp_command_complete(SCSIRequest *req, size_t resid)
845 {
846     ESPState *s = req->hba_private;
847     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
848 
849     trace_esp_command_complete();
850 
851     /*
852      * Non-DMA transfers from the target will leave the last byte in
853      * the FIFO so don't reset ti_size in this case
854      */
855     if (s->dma || to_device) {
856         if (s->ti_size != 0) {
857             trace_esp_command_complete_unexpected();
858         }
859         s->ti_size = 0;
860     }
861 
862     s->async_len = 0;
863     if (req->status) {
864         trace_esp_command_complete_fail();
865     }
866     s->status = req->status;
867 
868     /*
869      * If the transfer is finished, switch to status phase. For non-DMA
870      * transfers from the target the last byte is still in the FIFO
871      */
872     if (s->ti_size == 0) {
873         s->rregs[ESP_RSTAT] &= ~7;
874         s->rregs[ESP_RSTAT] |= STAT_ST;
875         esp_dma_done(s);
876         esp_lower_drq(s);
877     }
878 
879     if (s->current_req) {
880         scsi_req_unref(s->current_req);
881         s->current_req = NULL;
882         s->current_dev = NULL;
883     }
884 }
885 
886 void esp_transfer_data(SCSIRequest *req, uint32_t len)
887 {
888     ESPState *s = req->hba_private;
889     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
890     uint32_t dmalen = esp_get_tc(s);
891 
892     assert(!s->do_cmd);
893     trace_esp_transfer_data(dmalen, s->ti_size);
894     s->async_len = len;
895     s->async_buf = scsi_req_get_buf(req);
896 
897     if (!to_device && !s->data_in_ready) {
898         /*
899          * Initial incoming data xfer is complete so raise command
900          * completion interrupt
901          */
902         s->data_in_ready = true;
903         s->rregs[ESP_RSTAT] |= STAT_TC;
904         s->rregs[ESP_RINTR] |= INTR_BS;
905         esp_raise_irq(s);
906     }
907 
908     if (s->ti_cmd == 0) {
909         /*
910          * Always perform the initial transfer upon reception of the next TI
911          * command to ensure the DMA/non-DMA status of the command is correct.
912          * It is not possible to use s->dma directly in the section below as
913          * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
914          * async data transfer is delayed then s->dma is set incorrectly.
915          */
916         return;
917     }
918 
919     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
920         if (dmalen) {
921             esp_do_dma(s);
922         } else if (s->ti_size <= 0) {
923             /*
924              * If this was the last part of a DMA transfer then the
925              * completion interrupt is deferred to here.
926              */
927             esp_dma_done(s);
928             esp_lower_drq(s);
929         }
930     } else if (s->ti_cmd == CMD_TI) {
931         esp_do_nodma(s);
932     }
933 }
934 
935 static void handle_ti(ESPState *s)
936 {
937     uint32_t dmalen;
938 
939     if (s->dma && !s->dma_enabled) {
940         s->dma_cb = handle_ti;
941         return;
942     }
943 
944     s->ti_cmd = s->rregs[ESP_CMD];
945     if (s->dma) {
946         dmalen = esp_get_tc(s);
947         trace_esp_handle_ti(dmalen);
948         s->rregs[ESP_RSTAT] &= ~STAT_TC;
949         esp_do_dma(s);
950     } else {
951         trace_esp_handle_ti(s->ti_size);
952         esp_do_nodma(s);
953     }
954 }
955 
956 void esp_hard_reset(ESPState *s)
957 {
958     memset(s->rregs, 0, ESP_REGS);
959     memset(s->wregs, 0, ESP_REGS);
960     s->tchi_written = 0;
961     s->ti_size = 0;
962     s->async_len = 0;
963     fifo8_reset(&s->fifo);
964     fifo8_reset(&s->cmdfifo);
965     s->dma = 0;
966     s->do_cmd = 0;
967     s->dma_cb = NULL;
968 
969     s->rregs[ESP_CFG1] = 7;
970 }
971 
972 static void esp_soft_reset(ESPState *s)
973 {
974     qemu_irq_lower(s->irq);
975     qemu_irq_lower(s->irq_data);
976     esp_hard_reset(s);
977 }
978 
979 static void esp_bus_reset(ESPState *s)
980 {
981     bus_cold_reset(BUS(&s->bus));
982 }
983 
984 static void parent_esp_reset(ESPState *s, int irq, int level)
985 {
986     if (level) {
987         esp_soft_reset(s);
988     }
989 }
990 
991 static void esp_run_cmd(ESPState *s)
992 {
993     uint8_t cmd = s->rregs[ESP_CMD];
994 
995     if (cmd & CMD_DMA) {
996         s->dma = 1;
997         /* Reload DMA counter.  */
998         if (esp_get_stc(s) == 0) {
999             esp_set_tc(s, 0x10000);
1000         } else {
1001             esp_set_tc(s, esp_get_stc(s));
1002         }
1003     } else {
1004         s->dma = 0;
1005     }
1006     switch (cmd & CMD_CMD) {
1007     case CMD_NOP:
1008         trace_esp_mem_writeb_cmd_nop(cmd);
1009         break;
1010     case CMD_FLUSH:
1011         trace_esp_mem_writeb_cmd_flush(cmd);
1012         fifo8_reset(&s->fifo);
1013         break;
1014     case CMD_RESET:
1015         trace_esp_mem_writeb_cmd_reset(cmd);
1016         esp_soft_reset(s);
1017         break;
1018     case CMD_BUSRESET:
1019         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1020         esp_bus_reset(s);
1021         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1022             s->rregs[ESP_RINTR] |= INTR_RST;
1023             esp_raise_irq(s);
1024         }
1025         break;
1026     case CMD_TI:
1027         trace_esp_mem_writeb_cmd_ti(cmd);
1028         handle_ti(s);
1029         break;
1030     case CMD_ICCS:
1031         trace_esp_mem_writeb_cmd_iccs(cmd);
1032         write_response(s);
1033         s->rregs[ESP_RINTR] |= INTR_FC;
1034         s->rregs[ESP_RSTAT] |= STAT_MI;
1035         break;
1036     case CMD_MSGACC:
1037         trace_esp_mem_writeb_cmd_msgacc(cmd);
1038         s->rregs[ESP_RINTR] |= INTR_DC;
1039         s->rregs[ESP_RSEQ] = 0;
1040         s->rregs[ESP_RFLAGS] = 0;
1041         esp_raise_irq(s);
1042         break;
1043     case CMD_PAD:
1044         trace_esp_mem_writeb_cmd_pad(cmd);
1045         s->rregs[ESP_RSTAT] = STAT_TC;
1046         s->rregs[ESP_RINTR] |= INTR_FC;
1047         s->rregs[ESP_RSEQ] = 0;
1048         break;
1049     case CMD_SATN:
1050         trace_esp_mem_writeb_cmd_satn(cmd);
1051         break;
1052     case CMD_RSTATN:
1053         trace_esp_mem_writeb_cmd_rstatn(cmd);
1054         break;
1055     case CMD_SEL:
1056         trace_esp_mem_writeb_cmd_sel(cmd);
1057         handle_s_without_atn(s);
1058         break;
1059     case CMD_SELATN:
1060         trace_esp_mem_writeb_cmd_selatn(cmd);
1061         handle_satn(s);
1062         break;
1063     case CMD_SELATNS:
1064         trace_esp_mem_writeb_cmd_selatns(cmd);
1065         handle_satn_stop(s);
1066         break;
1067     case CMD_ENSEL:
1068         trace_esp_mem_writeb_cmd_ensel(cmd);
1069         s->rregs[ESP_RINTR] = 0;
1070         break;
1071     case CMD_DISSEL:
1072         trace_esp_mem_writeb_cmd_dissel(cmd);
1073         s->rregs[ESP_RINTR] = 0;
1074         esp_raise_irq(s);
1075         break;
1076     default:
1077         trace_esp_error_unhandled_command(cmd);
1078         break;
1079     }
1080 }
1081 
1082 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1083 {
1084     uint32_t val;
1085 
1086     switch (saddr) {
1087     case ESP_FIFO:
1088         if (s->dma_memory_read && s->dma_memory_write &&
1089                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1090             /* Data out.  */
1091             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1092             s->rregs[ESP_FIFO] = 0;
1093         } else {
1094             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1095                 if (s->ti_size) {
1096                     esp_do_nodma(s);
1097                 } else {
1098                     /*
1099                      * The last byte of a non-DMA transfer has been read out
1100                      * of the FIFO so switch to status phase
1101                      */
1102                     s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
1103                 }
1104             }
1105             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1106         }
1107         val = s->rregs[ESP_FIFO];
1108         break;
1109     case ESP_RINTR:
1110         /*
1111          * Clear sequence step, interrupt register and all status bits
1112          * except TC
1113          */
1114         val = s->rregs[ESP_RINTR];
1115         s->rregs[ESP_RINTR] = 0;
1116         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1117         /*
1118          * According to the datasheet ESP_RSEQ should be cleared, but as the
1119          * emulation currently defers information transfers to the next TI
1120          * command leave it for now so that pedantic guests such as the old
1121          * Linux 2.6 driver see the correct flags before the next SCSI phase
1122          * transition.
1123          *
1124          * s->rregs[ESP_RSEQ] = SEQ_0;
1125          */
1126         esp_lower_irq(s);
1127         break;
1128     case ESP_TCHI:
1129         /* Return the unique id if the value has never been written */
1130         if (!s->tchi_written) {
1131             val = s->chip_id;
1132         } else {
1133             val = s->rregs[saddr];
1134         }
1135         break;
1136      case ESP_RFLAGS:
1137         /* Bottom 5 bits indicate number of bytes in FIFO */
1138         val = fifo8_num_used(&s->fifo);
1139         break;
1140     default:
1141         val = s->rregs[saddr];
1142         break;
1143     }
1144 
1145     trace_esp_mem_readb(saddr, val);
1146     return val;
1147 }
1148 
1149 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1150 {
1151     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1152     switch (saddr) {
1153     case ESP_TCHI:
1154         s->tchi_written = true;
1155         /* fall through */
1156     case ESP_TCLO:
1157     case ESP_TCMID:
1158         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1159         break;
1160     case ESP_FIFO:
1161         if (s->do_cmd) {
1162             esp_fifo_push(&s->cmdfifo, val);
1163 
1164             /*
1165              * If any unexpected message out/command phase data is
1166              * transferred using non-DMA, raise the interrupt
1167              */
1168             if (s->rregs[ESP_CMD] == CMD_TI) {
1169                 s->rregs[ESP_RINTR] |= INTR_BS;
1170                 esp_raise_irq(s);
1171             }
1172         } else {
1173             esp_fifo_push(&s->fifo, val);
1174         }
1175         break;
1176     case ESP_CMD:
1177         s->rregs[saddr] = val;
1178         esp_run_cmd(s);
1179         break;
1180     case ESP_WBUSID ... ESP_WSYNO:
1181         break;
1182     case ESP_CFG1:
1183     case ESP_CFG2: case ESP_CFG3:
1184     case ESP_RES3: case ESP_RES4:
1185         s->rregs[saddr] = val;
1186         break;
1187     case ESP_WCCF ... ESP_WTEST:
1188         break;
1189     default:
1190         trace_esp_error_invalid_write(val, saddr);
1191         return;
1192     }
1193     s->wregs[saddr] = val;
1194 }
1195 
1196 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1197                             unsigned size, bool is_write,
1198                             MemTxAttrs attrs)
1199 {
1200     return (size == 1) || (is_write && size == 4);
1201 }
1202 
1203 static bool esp_is_before_version_5(void *opaque, int version_id)
1204 {
1205     ESPState *s = ESP(opaque);
1206 
1207     version_id = MIN(version_id, s->mig_version_id);
1208     return version_id < 5;
1209 }
1210 
1211 static bool esp_is_version_5(void *opaque, int version_id)
1212 {
1213     ESPState *s = ESP(opaque);
1214 
1215     version_id = MIN(version_id, s->mig_version_id);
1216     return version_id >= 5;
1217 }
1218 
1219 static bool esp_is_version_6(void *opaque, int version_id)
1220 {
1221     ESPState *s = ESP(opaque);
1222 
1223     version_id = MIN(version_id, s->mig_version_id);
1224     return version_id >= 6;
1225 }
1226 
1227 int esp_pre_save(void *opaque)
1228 {
1229     ESPState *s = ESP(object_resolve_path_component(
1230                       OBJECT(opaque), "esp"));
1231 
1232     s->mig_version_id = vmstate_esp.version_id;
1233     return 0;
1234 }
1235 
1236 static int esp_post_load(void *opaque, int version_id)
1237 {
1238     ESPState *s = ESP(opaque);
1239     int len, i;
1240 
1241     version_id = MIN(version_id, s->mig_version_id);
1242 
1243     if (version_id < 5) {
1244         esp_set_tc(s, s->mig_dma_left);
1245 
1246         /* Migrate ti_buf to fifo */
1247         len = s->mig_ti_wptr - s->mig_ti_rptr;
1248         for (i = 0; i < len; i++) {
1249             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1250         }
1251 
1252         /* Migrate cmdbuf to cmdfifo */
1253         for (i = 0; i < s->mig_cmdlen; i++) {
1254             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1255         }
1256     }
1257 
1258     s->mig_version_id = vmstate_esp.version_id;
1259     return 0;
1260 }
1261 
1262 /*
1263  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1264  * guest CPU to perform the transfers between the SCSI bus and memory
1265  * itself. This is indicated by the dma_memory_read and dma_memory_write
1266  * functions being NULL (in contrast to the ESP PCI device) whilst
1267  * dma_enabled is still set.
1268  */
1269 
1270 static bool esp_pdma_needed(void *opaque)
1271 {
1272     ESPState *s = ESP(opaque);
1273 
1274     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1275            s->dma_enabled;
1276 }
1277 
1278 static const VMStateDescription vmstate_esp_pdma = {
1279     .name = "esp/pdma",
1280     .version_id = 0,
1281     .minimum_version_id = 0,
1282     .needed = esp_pdma_needed,
1283     .fields = (const VMStateField[]) {
1284         VMSTATE_UINT8(pdma_cb, ESPState),
1285         VMSTATE_END_OF_LIST()
1286     }
1287 };
1288 
1289 const VMStateDescription vmstate_esp = {
1290     .name = "esp",
1291     .version_id = 6,
1292     .minimum_version_id = 3,
1293     .post_load = esp_post_load,
1294     .fields = (const VMStateField[]) {
1295         VMSTATE_BUFFER(rregs, ESPState),
1296         VMSTATE_BUFFER(wregs, ESPState),
1297         VMSTATE_INT32(ti_size, ESPState),
1298         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1299         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1300         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1301         VMSTATE_UINT32(status, ESPState),
1302         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1303                             esp_is_before_version_5),
1304         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1305                           esp_is_before_version_5),
1306         VMSTATE_UINT32(dma, ESPState),
1307         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1308                               esp_is_before_version_5, 0, 16),
1309         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1310                               esp_is_before_version_5, 16,
1311                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1312         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1313         VMSTATE_UINT32(do_cmd, ESPState),
1314         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1315         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1316         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1317         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1318         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1319         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1320         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1321         VMSTATE_END_OF_LIST()
1322     },
1323     .subsections = (const VMStateDescription * const []) {
1324         &vmstate_esp_pdma,
1325         NULL
1326     }
1327 };
1328 
1329 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1330                                  uint64_t val, unsigned int size)
1331 {
1332     SysBusESPState *sysbus = opaque;
1333     ESPState *s = ESP(&sysbus->esp);
1334     uint32_t saddr;
1335 
1336     saddr = addr >> sysbus->it_shift;
1337     esp_reg_write(s, saddr, val);
1338 }
1339 
1340 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1341                                     unsigned int size)
1342 {
1343     SysBusESPState *sysbus = opaque;
1344     ESPState *s = ESP(&sysbus->esp);
1345     uint32_t saddr;
1346 
1347     saddr = addr >> sysbus->it_shift;
1348     return esp_reg_read(s, saddr);
1349 }
1350 
1351 static const MemoryRegionOps sysbus_esp_mem_ops = {
1352     .read = sysbus_esp_mem_read,
1353     .write = sysbus_esp_mem_write,
1354     .endianness = DEVICE_NATIVE_ENDIAN,
1355     .valid.accepts = esp_mem_accepts,
1356 };
1357 
1358 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1359                                   uint64_t val, unsigned int size)
1360 {
1361     SysBusESPState *sysbus = opaque;
1362     ESPState *s = ESP(&sysbus->esp);
1363 
1364     trace_esp_pdma_write(size);
1365 
1366     switch (size) {
1367     case 1:
1368         esp_pdma_write(s, val);
1369         break;
1370     case 2:
1371         esp_pdma_write(s, val >> 8);
1372         esp_pdma_write(s, val);
1373         break;
1374     }
1375     esp_pdma_cb(s);
1376 }
1377 
1378 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1379                                      unsigned int size)
1380 {
1381     SysBusESPState *sysbus = opaque;
1382     ESPState *s = ESP(&sysbus->esp);
1383     uint64_t val = 0;
1384 
1385     trace_esp_pdma_read(size);
1386 
1387     switch (size) {
1388     case 1:
1389         val = esp_pdma_read(s);
1390         break;
1391     case 2:
1392         val = esp_pdma_read(s);
1393         val = (val << 8) | esp_pdma_read(s);
1394         break;
1395     }
1396     if (fifo8_num_used(&s->fifo) < 2) {
1397         esp_pdma_cb(s);
1398     }
1399     return val;
1400 }
1401 
1402 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1403 {
1404     ESPState *s = container_of(req->bus, ESPState, bus);
1405 
1406     scsi_req_ref(req);
1407     s->current_req = req;
1408     return s;
1409 }
1410 
1411 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1412     .read = sysbus_esp_pdma_read,
1413     .write = sysbus_esp_pdma_write,
1414     .endianness = DEVICE_NATIVE_ENDIAN,
1415     .valid.min_access_size = 1,
1416     .valid.max_access_size = 4,
1417     .impl.min_access_size = 1,
1418     .impl.max_access_size = 2,
1419 };
1420 
1421 static const struct SCSIBusInfo esp_scsi_info = {
1422     .tcq = false,
1423     .max_target = ESP_MAX_DEVS,
1424     .max_lun = 7,
1425 
1426     .load_request = esp_load_request,
1427     .transfer_data = esp_transfer_data,
1428     .complete = esp_command_complete,
1429     .cancel = esp_request_cancelled
1430 };
1431 
1432 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1433 {
1434     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1435     ESPState *s = ESP(&sysbus->esp);
1436 
1437     switch (irq) {
1438     case 0:
1439         parent_esp_reset(s, irq, level);
1440         break;
1441     case 1:
1442         esp_dma_enable(s, irq, level);
1443         break;
1444     }
1445 }
1446 
1447 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1448 {
1449     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1450     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1451     ESPState *s = ESP(&sysbus->esp);
1452 
1453     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1454         return;
1455     }
1456 
1457     sysbus_init_irq(sbd, &s->irq);
1458     sysbus_init_irq(sbd, &s->irq_data);
1459     assert(sysbus->it_shift != -1);
1460 
1461     s->chip_id = TCHI_FAS100A;
1462     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1463                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1464     sysbus_init_mmio(sbd, &sysbus->iomem);
1465     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1466                           sysbus, "esp-pdma", 4);
1467     sysbus_init_mmio(sbd, &sysbus->pdma);
1468 
1469     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1470 
1471     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1472 }
1473 
1474 static void sysbus_esp_hard_reset(DeviceState *dev)
1475 {
1476     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1477     ESPState *s = ESP(&sysbus->esp);
1478 
1479     esp_hard_reset(s);
1480 }
1481 
1482 static void sysbus_esp_init(Object *obj)
1483 {
1484     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1485 
1486     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1487 }
1488 
1489 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1490     .name = "sysbusespscsi",
1491     .version_id = 2,
1492     .minimum_version_id = 1,
1493     .pre_save = esp_pre_save,
1494     .fields = (const VMStateField[]) {
1495         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1496         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1497         VMSTATE_END_OF_LIST()
1498     }
1499 };
1500 
1501 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1502 {
1503     DeviceClass *dc = DEVICE_CLASS(klass);
1504 
1505     dc->realize = sysbus_esp_realize;
1506     dc->reset = sysbus_esp_hard_reset;
1507     dc->vmsd = &vmstate_sysbus_esp_scsi;
1508     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1509 }
1510 
1511 static const TypeInfo sysbus_esp_info = {
1512     .name          = TYPE_SYSBUS_ESP,
1513     .parent        = TYPE_SYS_BUS_DEVICE,
1514     .instance_init = sysbus_esp_init,
1515     .instance_size = sizeof(SysBusESPState),
1516     .class_init    = sysbus_esp_class_init,
1517 };
1518 
1519 static void esp_finalize(Object *obj)
1520 {
1521     ESPState *s = ESP(obj);
1522 
1523     fifo8_destroy(&s->fifo);
1524     fifo8_destroy(&s->cmdfifo);
1525 }
1526 
1527 static void esp_init(Object *obj)
1528 {
1529     ESPState *s = ESP(obj);
1530 
1531     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1532     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1533 }
1534 
1535 static void esp_class_init(ObjectClass *klass, void *data)
1536 {
1537     DeviceClass *dc = DEVICE_CLASS(klass);
1538 
1539     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1540     dc->user_creatable = false;
1541     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1542 }
1543 
1544 static const TypeInfo esp_info = {
1545     .name = TYPE_ESP,
1546     .parent = TYPE_DEVICE,
1547     .instance_init = esp_init,
1548     .instance_finalize = esp_finalize,
1549     .instance_size = sizeof(ESPState),
1550     .class_init = esp_class_init,
1551 };
1552 
1553 static void esp_register_types(void)
1554 {
1555     type_register_static(&sysbus_esp_info);
1556     type_register_static(&esp_info);
1557 }
1558 
1559 type_init(esp_register_types)
1560