xref: /qemu/hw/scsi/esp.c (revision fe082b54751dd4404c17a676a7d2f8630c91067c)
1 /*
2  * QEMU ESP/NCR53C9x emulation
3  *
4  * Copyright (c) 2005-2006 Fabrice Bellard
5  * Copyright (c) 2012 Herve Poussineau
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "hw/sysbus.h"
28 #include "migration/vmstate.h"
29 #include "hw/irq.h"
30 #include "hw/scsi/esp.h"
31 #include "trace.h"
32 #include "qemu/log.h"
33 #include "qemu/module.h"
34 
35 /*
36  * On Sparc32, this is the ESP (NCR53C90) part of chip STP2000 (Master I/O),
37  * also produced as NCR89C100. See
38  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
39  * and
40  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR53C9X.txt
41  *
42  * On Macintosh Quadra it is a NCR53C96.
43  */
44 
45 static void esp_raise_irq(ESPState *s)
46 {
47     if (!(s->rregs[ESP_RSTAT] & STAT_INT)) {
48         s->rregs[ESP_RSTAT] |= STAT_INT;
49         qemu_irq_raise(s->irq);
50         trace_esp_raise_irq();
51     }
52 }
53 
54 static void esp_lower_irq(ESPState *s)
55 {
56     if (s->rregs[ESP_RSTAT] & STAT_INT) {
57         s->rregs[ESP_RSTAT] &= ~STAT_INT;
58         qemu_irq_lower(s->irq);
59         trace_esp_lower_irq();
60     }
61 }
62 
63 static void esp_raise_drq(ESPState *s)
64 {
65     qemu_irq_raise(s->irq_data);
66     trace_esp_raise_drq();
67 }
68 
69 static void esp_lower_drq(ESPState *s)
70 {
71     qemu_irq_lower(s->irq_data);
72     trace_esp_lower_drq();
73 }
74 
75 void esp_dma_enable(ESPState *s, int irq, int level)
76 {
77     if (level) {
78         s->dma_enabled = 1;
79         trace_esp_dma_enable();
80         if (s->dma_cb) {
81             s->dma_cb(s);
82             s->dma_cb = NULL;
83         }
84     } else {
85         trace_esp_dma_disable();
86         s->dma_enabled = 0;
87     }
88 }
89 
90 void esp_request_cancelled(SCSIRequest *req)
91 {
92     ESPState *s = req->hba_private;
93 
94     if (req == s->current_req) {
95         scsi_req_unref(s->current_req);
96         s->current_req = NULL;
97         s->current_dev = NULL;
98         s->async_len = 0;
99     }
100 }
101 
102 static void esp_fifo_push(Fifo8 *fifo, uint8_t val)
103 {
104     if (fifo8_num_used(fifo) == fifo->capacity) {
105         trace_esp_error_fifo_overrun();
106         return;
107     }
108 
109     fifo8_push(fifo, val);
110 }
111 
112 static uint8_t esp_fifo_pop(Fifo8 *fifo)
113 {
114     if (fifo8_is_empty(fifo)) {
115         return 0;
116     }
117 
118     return fifo8_pop(fifo);
119 }
120 
121 static uint32_t esp_fifo_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen)
122 {
123     const uint8_t *buf;
124     uint32_t n, n2;
125     int len;
126 
127     if (maxlen == 0) {
128         return 0;
129     }
130 
131     len = maxlen;
132     buf = fifo8_pop_buf(fifo, len, &n);
133     if (dest) {
134         memcpy(dest, buf, n);
135     }
136 
137     /* Add FIFO wraparound if needed */
138     len -= n;
139     len = MIN(len, fifo8_num_used(fifo));
140     if (len) {
141         buf = fifo8_pop_buf(fifo, len, &n2);
142         if (dest) {
143             memcpy(&dest[n], buf, n2);
144         }
145         n += n2;
146     }
147 
148     return n;
149 }
150 
151 static uint32_t esp_get_tc(ESPState *s)
152 {
153     uint32_t dmalen;
154 
155     dmalen = s->rregs[ESP_TCLO];
156     dmalen |= s->rregs[ESP_TCMID] << 8;
157     dmalen |= s->rregs[ESP_TCHI] << 16;
158 
159     return dmalen;
160 }
161 
162 static void esp_set_tc(ESPState *s, uint32_t dmalen)
163 {
164     uint32_t old_tc = esp_get_tc(s);
165 
166     s->rregs[ESP_TCLO] = dmalen;
167     s->rregs[ESP_TCMID] = dmalen >> 8;
168     s->rregs[ESP_TCHI] = dmalen >> 16;
169 
170     if (old_tc && dmalen == 0) {
171         s->rregs[ESP_RSTAT] |= STAT_TC;
172     }
173 }
174 
175 static uint32_t esp_get_stc(ESPState *s)
176 {
177     uint32_t dmalen;
178 
179     dmalen = s->wregs[ESP_TCLO];
180     dmalen |= s->wregs[ESP_TCMID] << 8;
181     dmalen |= s->wregs[ESP_TCHI] << 16;
182 
183     return dmalen;
184 }
185 
186 static const char *esp_phase_names[8] = {
187     "DATA OUT", "DATA IN", "COMMAND", "STATUS",
188     "(reserved)", "(reserved)", "MESSAGE OUT", "MESSAGE IN"
189 };
190 
191 static void esp_set_phase(ESPState *s, uint8_t phase)
192 {
193     s->rregs[ESP_RSTAT] &= ~7;
194     s->rregs[ESP_RSTAT] |= phase;
195 
196     trace_esp_set_phase(esp_phase_names[phase]);
197 }
198 
199 static uint8_t esp_pdma_read(ESPState *s)
200 {
201     uint8_t val;
202 
203     val = esp_fifo_pop(&s->fifo);
204     return val;
205 }
206 
207 static void esp_pdma_write(ESPState *s, uint8_t val)
208 {
209     uint32_t dmalen = esp_get_tc(s);
210 
211     if (dmalen == 0) {
212         return;
213     }
214 
215     esp_fifo_push(&s->fifo, val);
216 
217     dmalen--;
218     esp_set_tc(s, dmalen);
219 }
220 
221 static void esp_set_pdma_cb(ESPState *s, enum pdma_cb cb)
222 {
223     s->pdma_cb = cb;
224 }
225 
226 static int esp_select(ESPState *s)
227 {
228     int target;
229 
230     target = s->wregs[ESP_WBUSID] & BUSID_DID;
231 
232     s->ti_size = 0;
233 
234     if (s->current_req) {
235         /* Started a new command before the old one finished. Cancel it. */
236         scsi_req_cancel(s->current_req);
237     }
238 
239     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
240     if (!s->current_dev) {
241         /* No such drive */
242         s->rregs[ESP_RSTAT] = 0;
243         s->rregs[ESP_RINTR] = INTR_DC;
244         s->rregs[ESP_RSEQ] = SEQ_0;
245         esp_raise_irq(s);
246         return -1;
247     }
248 
249     /*
250      * Note that we deliberately don't raise the IRQ here: this will be done
251      * either in do_command_phase() for DATA OUT transfers or by the deferred
252      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
253      */
254     s->rregs[ESP_RINTR] |= INTR_FC;
255     s->rregs[ESP_RSEQ] = SEQ_CD;
256     return 0;
257 }
258 
259 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
260 {
261     uint8_t buf[ESP_CMDFIFO_SZ];
262     uint32_t dmalen, n;
263     int target;
264 
265     target = s->wregs[ESP_WBUSID] & BUSID_DID;
266     if (s->dma) {
267         dmalen = MIN(esp_get_tc(s), maxlen);
268         if (dmalen == 0) {
269             return 0;
270         }
271         if (s->dma_memory_read) {
272             s->dma_memory_read(s->dma_opaque, buf, dmalen);
273             dmalen = MIN(fifo8_num_free(&s->cmdfifo), dmalen);
274             fifo8_push_all(&s->cmdfifo, buf, dmalen);
275             esp_set_tc(s, esp_get_tc(s) - dmalen);
276         } else {
277             return 0;
278         }
279     } else {
280         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
281         if (dmalen == 0) {
282             return 0;
283         }
284         n = esp_fifo_pop_buf(&s->fifo, buf, dmalen);
285         n = MIN(fifo8_num_free(&s->cmdfifo), n);
286         fifo8_push_all(&s->cmdfifo, buf, n);
287     }
288     trace_esp_get_cmd(dmalen, target);
289 
290     return dmalen;
291 }
292 
293 static void do_command_phase(ESPState *s)
294 {
295     uint32_t cmdlen;
296     int32_t datalen;
297     SCSIDevice *current_lun;
298     uint8_t buf[ESP_CMDFIFO_SZ];
299 
300     trace_esp_do_command_phase(s->lun);
301     cmdlen = fifo8_num_used(&s->cmdfifo);
302     if (!cmdlen || !s->current_dev) {
303         return;
304     }
305     esp_fifo_pop_buf(&s->cmdfifo, buf, cmdlen);
306 
307     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
308     if (!current_lun) {
309         /* No such drive */
310         s->rregs[ESP_RSTAT] = 0;
311         s->rregs[ESP_RINTR] = INTR_DC;
312         s->rregs[ESP_RSEQ] = SEQ_0;
313         esp_raise_irq(s);
314         return;
315     }
316 
317     s->current_req = scsi_req_new(current_lun, 0, s->lun, buf, cmdlen, s);
318     datalen = scsi_req_enqueue(s->current_req);
319     s->ti_size = datalen;
320     fifo8_reset(&s->cmdfifo);
321     if (datalen != 0) {
322         s->ti_cmd = 0;
323         if (datalen > 0) {
324             /*
325              * Switch to DATA IN phase but wait until initial data xfer is
326              * complete before raising the command completion interrupt
327              */
328             s->data_in_ready = false;
329             esp_set_phase(s, STAT_DI);
330         } else {
331             esp_set_phase(s, STAT_DO);
332             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
333             esp_raise_irq(s);
334             esp_lower_drq(s);
335         }
336         scsi_req_continue(s->current_req);
337         return;
338     }
339 }
340 
341 static void do_message_phase(ESPState *s)
342 {
343     if (s->cmdfifo_cdb_offset) {
344         uint8_t message = esp_fifo_pop(&s->cmdfifo);
345 
346         trace_esp_do_identify(message);
347         s->lun = message & 7;
348         s->cmdfifo_cdb_offset--;
349     }
350 
351     /* Ignore extended messages for now */
352     if (s->cmdfifo_cdb_offset) {
353         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
354         esp_fifo_pop_buf(&s->cmdfifo, NULL, len);
355         s->cmdfifo_cdb_offset = 0;
356     }
357 }
358 
359 static void do_cmd(ESPState *s)
360 {
361     do_message_phase(s);
362     assert(s->cmdfifo_cdb_offset == 0);
363     do_command_phase(s);
364 }
365 
366 static void satn_pdma_cb(ESPState *s)
367 {
368     uint8_t buf[ESP_FIFO_SZ];
369     int n;
370 
371     /* Copy FIFO into cmdfifo */
372     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
373     n = MIN(fifo8_num_free(&s->cmdfifo), n);
374     fifo8_push_all(&s->cmdfifo, buf, n);
375 
376     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
377         s->cmdfifo_cdb_offset = 1;
378         s->do_cmd = 0;
379         do_cmd(s);
380     }
381 }
382 
383 static void handle_satn(ESPState *s)
384 {
385     int32_t cmdlen;
386 
387     if (s->dma && !s->dma_enabled) {
388         s->dma_cb = handle_satn;
389         return;
390     }
391     esp_set_pdma_cb(s, SATN_PDMA_CB);
392     if (esp_select(s) < 0) {
393         return;
394     }
395     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
396     if (cmdlen > 0) {
397         s->cmdfifo_cdb_offset = 1;
398         s->do_cmd = 0;
399         do_cmd(s);
400     } else if (cmdlen == 0) {
401         if (s->dma) {
402             esp_raise_drq(s);
403         }
404         s->do_cmd = 1;
405         /* Target present, but no cmd yet - switch to command phase */
406         s->rregs[ESP_RSEQ] = SEQ_CD;
407         esp_set_phase(s, STAT_CD);
408     }
409 }
410 
411 static void s_without_satn_pdma_cb(ESPState *s)
412 {
413     uint8_t buf[ESP_FIFO_SZ];
414     int n;
415 
416     /* Copy FIFO into cmdfifo */
417     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
418     n = MIN(fifo8_num_free(&s->cmdfifo), n);
419     fifo8_push_all(&s->cmdfifo, buf, n);
420 
421     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
422         s->cmdfifo_cdb_offset = 0;
423         s->do_cmd = 0;
424         do_cmd(s);
425     }
426 }
427 
428 static void handle_s_without_atn(ESPState *s)
429 {
430     int32_t cmdlen;
431 
432     if (s->dma && !s->dma_enabled) {
433         s->dma_cb = handle_s_without_atn;
434         return;
435     }
436     esp_set_pdma_cb(s, S_WITHOUT_SATN_PDMA_CB);
437     if (esp_select(s) < 0) {
438         return;
439     }
440     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
441     if (cmdlen > 0) {
442         s->cmdfifo_cdb_offset = 0;
443         s->do_cmd = 0;
444         do_cmd(s);
445     } else if (cmdlen == 0) {
446         if (s->dma) {
447             esp_raise_drq(s);
448         }
449         s->do_cmd = 1;
450         /* Target present, but no cmd yet - switch to command phase */
451         s->rregs[ESP_RSEQ] = SEQ_CD;
452         esp_set_phase(s, STAT_CD);
453     }
454 }
455 
456 static void satn_stop_pdma_cb(ESPState *s)
457 {
458     uint8_t buf[ESP_FIFO_SZ];
459     int n;
460 
461     /* Copy FIFO into cmdfifo */
462     n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
463     n = MIN(fifo8_num_free(&s->cmdfifo), n);
464     fifo8_push_all(&s->cmdfifo, buf, n);
465 
466     if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
467         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
468         s->do_cmd = 1;
469         s->cmdfifo_cdb_offset = 1;
470         esp_set_phase(s, STAT_CD);
471         s->rregs[ESP_RSTAT] |= STAT_TC;
472         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
473         s->rregs[ESP_RSEQ] = SEQ_CD;
474         esp_raise_irq(s);
475     }
476 }
477 
478 static void handle_satn_stop(ESPState *s)
479 {
480     int32_t cmdlen;
481 
482     if (s->dma && !s->dma_enabled) {
483         s->dma_cb = handle_satn_stop;
484         return;
485     }
486     esp_set_pdma_cb(s, SATN_STOP_PDMA_CB);
487     if (esp_select(s) < 0) {
488         return;
489     }
490     cmdlen = get_cmd(s, 1);
491     if (cmdlen > 0) {
492         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
493         s->do_cmd = 1;
494         s->cmdfifo_cdb_offset = 1;
495         esp_set_phase(s, STAT_MO);
496         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
497         s->rregs[ESP_RSEQ] = SEQ_MO;
498         esp_raise_irq(s);
499     } else if (cmdlen == 0) {
500         if (s->dma) {
501             esp_raise_drq(s);
502         }
503         s->do_cmd = 1;
504         /* Target present, switch to message out phase */
505         s->rregs[ESP_RSEQ] = SEQ_MO;
506         esp_set_phase(s, STAT_MO);
507     }
508 }
509 
510 static void write_response_pdma_cb(ESPState *s)
511 {
512     esp_set_phase(s, STAT_ST);
513     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
514     s->rregs[ESP_RSEQ] = SEQ_CD;
515     esp_raise_irq(s);
516 }
517 
518 static void write_response(ESPState *s)
519 {
520     uint8_t buf[2];
521 
522     trace_esp_write_response(s->status);
523 
524     buf[0] = s->status;
525     buf[1] = 0;
526 
527     if (s->dma) {
528         if (s->dma_memory_write) {
529             s->dma_memory_write(s->dma_opaque, buf, 2);
530             esp_set_phase(s, STAT_ST);
531             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
532             s->rregs[ESP_RSEQ] = SEQ_CD;
533         } else {
534             esp_set_pdma_cb(s, WRITE_RESPONSE_PDMA_CB);
535             esp_raise_drq(s);
536             return;
537         }
538     } else {
539         fifo8_reset(&s->fifo);
540         fifo8_push_all(&s->fifo, buf, 2);
541         s->rregs[ESP_RFLAGS] = 2;
542     }
543     esp_raise_irq(s);
544 }
545 
546 static void esp_dma_done(ESPState *s)
547 {
548     s->rregs[ESP_RINTR] |= INTR_BS;
549     esp_raise_irq(s);
550 }
551 
552 static void do_dma_pdma_cb(ESPState *s)
553 {
554     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
555     uint8_t buf[ESP_CMDFIFO_SZ];
556     int len;
557     uint32_t n;
558 
559     if (s->do_cmd) {
560         /* Copy FIFO into cmdfifo */
561         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
562         n = MIN(fifo8_num_free(&s->cmdfifo), n);
563         fifo8_push_all(&s->cmdfifo, buf, n);
564 
565         /* Ensure we have received complete command after SATN and stop */
566         if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) {
567             return;
568         }
569 
570         s->ti_size = 0;
571         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
572             /* No command received */
573             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
574                 return;
575             }
576 
577             /* Command has been received */
578             s->do_cmd = 0;
579             do_cmd(s);
580         } else {
581             /*
582              * Extra message out bytes received: update cmdfifo_cdb_offset
583              * and then switch to command phase
584              */
585             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
586             esp_set_phase(s, STAT_CD);
587             s->rregs[ESP_RSEQ] = SEQ_CD;
588             s->rregs[ESP_RINTR] |= INTR_BS;
589             esp_raise_irq(s);
590         }
591         return;
592     }
593 
594     if (!s->current_req) {
595         return;
596     }
597 
598     if (to_device) {
599         /* Copy FIFO data to device */
600         len = MIN(s->async_len, ESP_FIFO_SZ);
601         len = MIN(len, fifo8_num_used(&s->fifo));
602         n = esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
603         s->async_buf += n;
604         s->async_len -= n;
605         s->ti_size += n;
606 
607         if (s->async_len == 0) {
608             scsi_req_continue(s->current_req);
609             return;
610         }
611 
612         if (esp_get_tc(s) == 0) {
613             esp_lower_drq(s);
614             esp_dma_done(s);
615         }
616 
617         return;
618     } else {
619         if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
620             /* Defer until the scsi layer has completed */
621             scsi_req_continue(s->current_req);
622             s->data_in_ready = false;
623             return;
624         }
625 
626         if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
627             esp_lower_drq(s);
628             esp_dma_done(s);
629         }
630 
631         /* Copy device data to FIFO */
632         len = MIN(s->async_len, esp_get_tc(s));
633         len = MIN(len, fifo8_num_free(&s->fifo));
634         fifo8_push_all(&s->fifo, s->async_buf, len);
635         s->async_buf += len;
636         s->async_len -= len;
637         s->ti_size -= len;
638         esp_set_tc(s, esp_get_tc(s) - len);
639     }
640 }
641 
642 static void esp_do_dma(ESPState *s)
643 {
644     uint32_t len, cmdlen;
645     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
646     uint8_t buf[ESP_CMDFIFO_SZ];
647 
648     len = esp_get_tc(s);
649     if (s->do_cmd) {
650         /*
651          * handle_ti_cmd() case: esp_do_dma() is called only from
652          * handle_ti_cmd() with do_cmd != NULL (see the assert())
653          */
654         cmdlen = fifo8_num_used(&s->cmdfifo);
655         trace_esp_do_dma(cmdlen, len);
656         if (s->dma_memory_read) {
657             len = MIN(len, fifo8_num_free(&s->cmdfifo));
658             s->dma_memory_read(s->dma_opaque, buf, len);
659             fifo8_push_all(&s->cmdfifo, buf, len);
660             esp_set_tc(s, esp_get_tc(s) - len);
661         } else {
662             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
663             esp_raise_drq(s);
664             return;
665         }
666         trace_esp_handle_ti_cmd(cmdlen);
667         s->ti_size = 0;
668         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
669             /* No command received */
670             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
671                 return;
672             }
673 
674             /* Command has been received */
675             s->do_cmd = 0;
676             do_cmd(s);
677         } else {
678             /*
679              * Extra message out bytes received: update cmdfifo_cdb_offset
680              * and then switch to command phase
681              */
682             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
683             esp_set_phase(s, STAT_CD);
684             s->rregs[ESP_RSEQ] = SEQ_CD;
685             s->rregs[ESP_RINTR] |= INTR_BS;
686             esp_raise_irq(s);
687         }
688         return;
689     }
690     if (!s->current_req) {
691         return;
692     }
693     if (s->async_len == 0) {
694         /* Defer until data is available.  */
695         return;
696     }
697     if (len > s->async_len) {
698         len = s->async_len;
699     }
700     if (to_device) {
701         if (s->dma_memory_read) {
702             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
703 
704             esp_set_tc(s, esp_get_tc(s) - len);
705             s->async_buf += len;
706             s->async_len -= len;
707             s->ti_size += len;
708 
709             if (s->async_len == 0) {
710                 scsi_req_continue(s->current_req);
711                 /*
712                  * If there is still data to be read from the device then
713                  * complete the DMA operation immediately.  Otherwise defer
714                  * until the scsi layer has completed.
715                  */
716                 return;
717             }
718 
719             if (esp_get_tc(s) == 0) {
720                 /* Partially filled a scsi buffer. Complete immediately.  */
721                 esp_dma_done(s);
722                 esp_lower_drq(s);
723             }
724         } else {
725             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
726             esp_raise_drq(s);
727         }
728     } else {
729         if (s->dma_memory_write) {
730             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
731 
732             esp_set_tc(s, esp_get_tc(s) - len);
733             s->async_buf += len;
734             s->async_len -= len;
735             s->ti_size -= len;
736 
737             if (s->async_len == 0) {
738                 scsi_req_continue(s->current_req);
739                 return;
740             }
741 
742             if (esp_get_tc(s) == 0) {
743                 /* Partially filled a scsi buffer. Complete immediately.  */
744                 esp_dma_done(s);
745                 esp_lower_drq(s);
746             }
747         } else {
748             /* Copy device data to FIFO */
749             len = MIN(len, fifo8_num_free(&s->fifo));
750             fifo8_push_all(&s->fifo, s->async_buf, len);
751             s->async_buf += len;
752             s->async_len -= len;
753             s->ti_size -= len;
754             esp_set_tc(s, esp_get_tc(s) - len);
755             esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
756             esp_raise_drq(s);
757         }
758     }
759 }
760 
761 static void esp_do_nodma(ESPState *s)
762 {
763     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
764     uint8_t buf[ESP_FIFO_SZ];
765     uint32_t cmdlen;
766     int len, n;
767 
768     if (s->do_cmd) {
769         /* Copy FIFO into cmdfifo */
770         n = esp_fifo_pop_buf(&s->fifo, buf, fifo8_num_used(&s->fifo));
771         n = MIN(fifo8_num_free(&s->cmdfifo), n);
772         fifo8_push_all(&s->cmdfifo, buf, n);
773 
774         cmdlen = fifo8_num_used(&s->cmdfifo);
775         trace_esp_handle_ti_cmd(cmdlen);
776         s->ti_size = 0;
777         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
778             /* No command received */
779             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
780                 return;
781             }
782 
783             /* Command has been received */
784             s->do_cmd = 0;
785             do_cmd(s);
786         } else {
787             /*
788              * Extra message out bytes received: update cmdfifo_cdb_offset
789              * and then switch to command phase
790              */
791             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
792             esp_set_phase(s, STAT_CD);
793             s->rregs[ESP_RSEQ] = SEQ_CD;
794             s->rregs[ESP_RINTR] |= INTR_BS;
795             esp_raise_irq(s);
796         }
797         return;
798     }
799 
800     if (!s->current_req) {
801         return;
802     }
803 
804     if (s->async_len == 0) {
805         /* Defer until data is available.  */
806         return;
807     }
808 
809     if (to_device) {
810         len = MIN(s->async_len, ESP_FIFO_SZ);
811         len = MIN(len, fifo8_num_used(&s->fifo));
812         esp_fifo_pop_buf(&s->fifo, s->async_buf, len);
813         s->async_buf += len;
814         s->async_len -= len;
815         s->ti_size += len;
816     } else {
817         if (fifo8_is_empty(&s->fifo)) {
818             fifo8_push(&s->fifo, s->async_buf[0]);
819             s->async_buf++;
820             s->async_len--;
821             s->ti_size--;
822         }
823     }
824 
825     if (s->async_len == 0) {
826         scsi_req_continue(s->current_req);
827         return;
828     }
829 
830     s->rregs[ESP_RINTR] |= INTR_BS;
831     esp_raise_irq(s);
832 }
833 
834 static void esp_pdma_cb(ESPState *s)
835 {
836     switch (s->pdma_cb) {
837     case SATN_PDMA_CB:
838         satn_pdma_cb(s);
839         break;
840     case S_WITHOUT_SATN_PDMA_CB:
841         s_without_satn_pdma_cb(s);
842         break;
843     case SATN_STOP_PDMA_CB:
844         satn_stop_pdma_cb(s);
845         break;
846     case WRITE_RESPONSE_PDMA_CB:
847         write_response_pdma_cb(s);
848         break;
849     case DO_DMA_PDMA_CB:
850         do_dma_pdma_cb(s);
851         break;
852     default:
853         g_assert_not_reached();
854     }
855 }
856 
857 void esp_command_complete(SCSIRequest *req, size_t resid)
858 {
859     ESPState *s = req->hba_private;
860     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
861 
862     trace_esp_command_complete();
863 
864     /*
865      * Non-DMA transfers from the target will leave the last byte in
866      * the FIFO so don't reset ti_size in this case
867      */
868     if (s->dma || to_device) {
869         if (s->ti_size != 0) {
870             trace_esp_command_complete_unexpected();
871         }
872         s->ti_size = 0;
873     }
874 
875     s->async_len = 0;
876     if (req->status) {
877         trace_esp_command_complete_fail();
878     }
879     s->status = req->status;
880 
881     /*
882      * If the transfer is finished, switch to status phase. For non-DMA
883      * transfers from the target the last byte is still in the FIFO
884      */
885     if (s->ti_size == 0) {
886         esp_set_phase(s, STAT_ST);
887         esp_dma_done(s);
888         esp_lower_drq(s);
889     }
890 
891     if (s->current_req) {
892         scsi_req_unref(s->current_req);
893         s->current_req = NULL;
894         s->current_dev = NULL;
895     }
896 }
897 
898 void esp_transfer_data(SCSIRequest *req, uint32_t len)
899 {
900     ESPState *s = req->hba_private;
901     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
902     uint32_t dmalen = esp_get_tc(s);
903 
904     assert(!s->do_cmd);
905     trace_esp_transfer_data(dmalen, s->ti_size);
906     s->async_len = len;
907     s->async_buf = scsi_req_get_buf(req);
908 
909     if (!to_device && !s->data_in_ready) {
910         /*
911          * Initial incoming data xfer is complete so raise command
912          * completion interrupt
913          */
914         s->data_in_ready = true;
915         s->rregs[ESP_RINTR] |= INTR_BS;
916         esp_raise_irq(s);
917     }
918 
919     /*
920      * Always perform the initial transfer upon reception of the next TI
921      * command to ensure the DMA/non-DMA status of the command is correct.
922      * It is not possible to use s->dma directly in the section below as
923      * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
924      * async data transfer is delayed then s->dma is set incorrectly.
925      */
926 
927     if (s->ti_cmd == (CMD_TI | CMD_DMA)) {
928         if (dmalen) {
929             esp_do_dma(s);
930         } else if (s->ti_size <= 0) {
931             /*
932              * If this was the last part of a DMA transfer then the
933              * completion interrupt is deferred to here.
934              */
935             esp_dma_done(s);
936             esp_lower_drq(s);
937         }
938     } else if (s->ti_cmd == CMD_TI) {
939         esp_do_nodma(s);
940     }
941 }
942 
943 static void handle_ti(ESPState *s)
944 {
945     uint32_t dmalen;
946 
947     if (s->dma && !s->dma_enabled) {
948         s->dma_cb = handle_ti;
949         return;
950     }
951 
952     s->ti_cmd = s->rregs[ESP_CMD];
953     if (s->dma) {
954         dmalen = esp_get_tc(s);
955         trace_esp_handle_ti(dmalen);
956         esp_do_dma(s);
957     } else {
958         trace_esp_handle_ti(s->ti_size);
959         esp_do_nodma(s);
960     }
961 }
962 
963 void esp_hard_reset(ESPState *s)
964 {
965     memset(s->rregs, 0, ESP_REGS);
966     memset(s->wregs, 0, ESP_REGS);
967     s->tchi_written = 0;
968     s->ti_size = 0;
969     s->async_len = 0;
970     fifo8_reset(&s->fifo);
971     fifo8_reset(&s->cmdfifo);
972     s->dma = 0;
973     s->do_cmd = 0;
974     s->dma_cb = NULL;
975 
976     s->rregs[ESP_CFG1] = 7;
977 }
978 
979 static void esp_soft_reset(ESPState *s)
980 {
981     qemu_irq_lower(s->irq);
982     qemu_irq_lower(s->irq_data);
983     esp_hard_reset(s);
984 }
985 
986 static void esp_bus_reset(ESPState *s)
987 {
988     bus_cold_reset(BUS(&s->bus));
989 }
990 
991 static void parent_esp_reset(ESPState *s, int irq, int level)
992 {
993     if (level) {
994         esp_soft_reset(s);
995     }
996 }
997 
998 static void esp_run_cmd(ESPState *s)
999 {
1000     uint8_t cmd = s->rregs[ESP_CMD];
1001 
1002     if (cmd & CMD_DMA) {
1003         s->dma = 1;
1004         /* Reload DMA counter.  */
1005         if (esp_get_stc(s) == 0) {
1006             esp_set_tc(s, 0x10000);
1007         } else {
1008             esp_set_tc(s, esp_get_stc(s));
1009         }
1010     } else {
1011         s->dma = 0;
1012     }
1013     switch (cmd & CMD_CMD) {
1014     case CMD_NOP:
1015         trace_esp_mem_writeb_cmd_nop(cmd);
1016         break;
1017     case CMD_FLUSH:
1018         trace_esp_mem_writeb_cmd_flush(cmd);
1019         fifo8_reset(&s->fifo);
1020         break;
1021     case CMD_RESET:
1022         trace_esp_mem_writeb_cmd_reset(cmd);
1023         esp_soft_reset(s);
1024         break;
1025     case CMD_BUSRESET:
1026         trace_esp_mem_writeb_cmd_bus_reset(cmd);
1027         esp_bus_reset(s);
1028         if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
1029             s->rregs[ESP_RINTR] |= INTR_RST;
1030             esp_raise_irq(s);
1031         }
1032         break;
1033     case CMD_TI:
1034         trace_esp_mem_writeb_cmd_ti(cmd);
1035         handle_ti(s);
1036         break;
1037     case CMD_ICCS:
1038         trace_esp_mem_writeb_cmd_iccs(cmd);
1039         write_response(s);
1040         s->rregs[ESP_RINTR] |= INTR_FC;
1041         esp_set_phase(s, STAT_MI);
1042         break;
1043     case CMD_MSGACC:
1044         trace_esp_mem_writeb_cmd_msgacc(cmd);
1045         s->rregs[ESP_RINTR] |= INTR_DC;
1046         s->rregs[ESP_RSEQ] = 0;
1047         s->rregs[ESP_RFLAGS] = 0;
1048         esp_raise_irq(s);
1049         break;
1050     case CMD_PAD:
1051         trace_esp_mem_writeb_cmd_pad(cmd);
1052         s->rregs[ESP_RSTAT] = STAT_TC;
1053         s->rregs[ESP_RINTR] |= INTR_FC;
1054         s->rregs[ESP_RSEQ] = 0;
1055         break;
1056     case CMD_SATN:
1057         trace_esp_mem_writeb_cmd_satn(cmd);
1058         break;
1059     case CMD_RSTATN:
1060         trace_esp_mem_writeb_cmd_rstatn(cmd);
1061         break;
1062     case CMD_SEL:
1063         trace_esp_mem_writeb_cmd_sel(cmd);
1064         handle_s_without_atn(s);
1065         break;
1066     case CMD_SELATN:
1067         trace_esp_mem_writeb_cmd_selatn(cmd);
1068         handle_satn(s);
1069         break;
1070     case CMD_SELATNS:
1071         trace_esp_mem_writeb_cmd_selatns(cmd);
1072         handle_satn_stop(s);
1073         break;
1074     case CMD_ENSEL:
1075         trace_esp_mem_writeb_cmd_ensel(cmd);
1076         s->rregs[ESP_RINTR] = 0;
1077         break;
1078     case CMD_DISSEL:
1079         trace_esp_mem_writeb_cmd_dissel(cmd);
1080         s->rregs[ESP_RINTR] = 0;
1081         esp_raise_irq(s);
1082         break;
1083     default:
1084         trace_esp_error_unhandled_command(cmd);
1085         break;
1086     }
1087 }
1088 
1089 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
1090 {
1091     uint32_t val;
1092 
1093     switch (saddr) {
1094     case ESP_FIFO:
1095         if (s->dma_memory_read && s->dma_memory_write &&
1096                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
1097             /* Data out.  */
1098             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
1099             s->rregs[ESP_FIFO] = 0;
1100         } else {
1101             if ((s->rregs[ESP_RSTAT] & 0x7) == STAT_DI) {
1102                 if (s->ti_size) {
1103                     esp_do_nodma(s);
1104                 } else {
1105                     /*
1106                      * The last byte of a non-DMA transfer has been read out
1107                      * of the FIFO so switch to status phase
1108                      */
1109                     esp_set_phase(s, STAT_ST);
1110                 }
1111             }
1112             s->rregs[ESP_FIFO] = esp_fifo_pop(&s->fifo);
1113         }
1114         val = s->rregs[ESP_FIFO];
1115         break;
1116     case ESP_RINTR:
1117         /*
1118          * Clear sequence step, interrupt register and all status bits
1119          * except TC
1120          */
1121         val = s->rregs[ESP_RINTR];
1122         s->rregs[ESP_RINTR] = 0;
1123         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1124         /*
1125          * According to the datasheet ESP_RSEQ should be cleared, but as the
1126          * emulation currently defers information transfers to the next TI
1127          * command leave it for now so that pedantic guests such as the old
1128          * Linux 2.6 driver see the correct flags before the next SCSI phase
1129          * transition.
1130          *
1131          * s->rregs[ESP_RSEQ] = SEQ_0;
1132          */
1133         esp_lower_irq(s);
1134         break;
1135     case ESP_TCHI:
1136         /* Return the unique id if the value has never been written */
1137         if (!s->tchi_written) {
1138             val = s->chip_id;
1139         } else {
1140             val = s->rregs[saddr];
1141         }
1142         break;
1143      case ESP_RFLAGS:
1144         /* Bottom 5 bits indicate number of bytes in FIFO */
1145         val = fifo8_num_used(&s->fifo);
1146         break;
1147     default:
1148         val = s->rregs[saddr];
1149         break;
1150     }
1151 
1152     trace_esp_mem_readb(saddr, val);
1153     return val;
1154 }
1155 
1156 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
1157 {
1158     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
1159     switch (saddr) {
1160     case ESP_TCHI:
1161         s->tchi_written = true;
1162         /* fall through */
1163     case ESP_TCLO:
1164     case ESP_TCMID:
1165         s->rregs[ESP_RSTAT] &= ~STAT_TC;
1166         break;
1167     case ESP_FIFO:
1168         if (s->do_cmd) {
1169             if (!fifo8_is_full(&s->fifo)) {
1170                 esp_fifo_push(&s->fifo, val);
1171                 esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
1172             }
1173 
1174             /*
1175              * If any unexpected message out/command phase data is
1176              * transferred using non-DMA, raise the interrupt
1177              */
1178             if (s->rregs[ESP_CMD] == CMD_TI) {
1179                 s->rregs[ESP_RINTR] |= INTR_BS;
1180                 esp_raise_irq(s);
1181             }
1182         } else {
1183             esp_fifo_push(&s->fifo, val);
1184         }
1185         break;
1186     case ESP_CMD:
1187         s->rregs[saddr] = val;
1188         esp_run_cmd(s);
1189         break;
1190     case ESP_WBUSID ... ESP_WSYNO:
1191         break;
1192     case ESP_CFG1:
1193     case ESP_CFG2: case ESP_CFG3:
1194     case ESP_RES3: case ESP_RES4:
1195         s->rregs[saddr] = val;
1196         break;
1197     case ESP_WCCF ... ESP_WTEST:
1198         break;
1199     default:
1200         trace_esp_error_invalid_write(val, saddr);
1201         return;
1202     }
1203     s->wregs[saddr] = val;
1204 }
1205 
1206 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1207                             unsigned size, bool is_write,
1208                             MemTxAttrs attrs)
1209 {
1210     return (size == 1) || (is_write && size == 4);
1211 }
1212 
1213 static bool esp_is_before_version_5(void *opaque, int version_id)
1214 {
1215     ESPState *s = ESP(opaque);
1216 
1217     version_id = MIN(version_id, s->mig_version_id);
1218     return version_id < 5;
1219 }
1220 
1221 static bool esp_is_version_5(void *opaque, int version_id)
1222 {
1223     ESPState *s = ESP(opaque);
1224 
1225     version_id = MIN(version_id, s->mig_version_id);
1226     return version_id >= 5;
1227 }
1228 
1229 static bool esp_is_version_6(void *opaque, int version_id)
1230 {
1231     ESPState *s = ESP(opaque);
1232 
1233     version_id = MIN(version_id, s->mig_version_id);
1234     return version_id >= 6;
1235 }
1236 
1237 int esp_pre_save(void *opaque)
1238 {
1239     ESPState *s = ESP(object_resolve_path_component(
1240                       OBJECT(opaque), "esp"));
1241 
1242     s->mig_version_id = vmstate_esp.version_id;
1243     return 0;
1244 }
1245 
1246 static int esp_post_load(void *opaque, int version_id)
1247 {
1248     ESPState *s = ESP(opaque);
1249     int len, i;
1250 
1251     version_id = MIN(version_id, s->mig_version_id);
1252 
1253     if (version_id < 5) {
1254         esp_set_tc(s, s->mig_dma_left);
1255 
1256         /* Migrate ti_buf to fifo */
1257         len = s->mig_ti_wptr - s->mig_ti_rptr;
1258         for (i = 0; i < len; i++) {
1259             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1260         }
1261 
1262         /* Migrate cmdbuf to cmdfifo */
1263         for (i = 0; i < s->mig_cmdlen; i++) {
1264             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1265         }
1266     }
1267 
1268     s->mig_version_id = vmstate_esp.version_id;
1269     return 0;
1270 }
1271 
1272 /*
1273  * PDMA (or pseudo-DMA) is only used on the Macintosh and requires the
1274  * guest CPU to perform the transfers between the SCSI bus and memory
1275  * itself. This is indicated by the dma_memory_read and dma_memory_write
1276  * functions being NULL (in contrast to the ESP PCI device) whilst
1277  * dma_enabled is still set.
1278  */
1279 
1280 static bool esp_pdma_needed(void *opaque)
1281 {
1282     ESPState *s = ESP(opaque);
1283 
1284     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
1285            s->dma_enabled;
1286 }
1287 
1288 static const VMStateDescription vmstate_esp_pdma = {
1289     .name = "esp/pdma",
1290     .version_id = 0,
1291     .minimum_version_id = 0,
1292     .needed = esp_pdma_needed,
1293     .fields = (const VMStateField[]) {
1294         VMSTATE_UINT8(pdma_cb, ESPState),
1295         VMSTATE_END_OF_LIST()
1296     }
1297 };
1298 
1299 const VMStateDescription vmstate_esp = {
1300     .name = "esp",
1301     .version_id = 6,
1302     .minimum_version_id = 3,
1303     .post_load = esp_post_load,
1304     .fields = (const VMStateField[]) {
1305         VMSTATE_BUFFER(rregs, ESPState),
1306         VMSTATE_BUFFER(wregs, ESPState),
1307         VMSTATE_INT32(ti_size, ESPState),
1308         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1309         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1310         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1311         VMSTATE_UINT32(status, ESPState),
1312         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1313                             esp_is_before_version_5),
1314         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1315                           esp_is_before_version_5),
1316         VMSTATE_UINT32(dma, ESPState),
1317         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1318                               esp_is_before_version_5, 0, 16),
1319         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1320                               esp_is_before_version_5, 16,
1321                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1322         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1323         VMSTATE_UINT32(do_cmd, ESPState),
1324         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1325         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1326         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1327         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1328         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1329         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1330         VMSTATE_UINT8_TEST(lun, ESPState, esp_is_version_6),
1331         VMSTATE_END_OF_LIST()
1332     },
1333     .subsections = (const VMStateDescription * const []) {
1334         &vmstate_esp_pdma,
1335         NULL
1336     }
1337 };
1338 
1339 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1340                                  uint64_t val, unsigned int size)
1341 {
1342     SysBusESPState *sysbus = opaque;
1343     ESPState *s = ESP(&sysbus->esp);
1344     uint32_t saddr;
1345 
1346     saddr = addr >> sysbus->it_shift;
1347     esp_reg_write(s, saddr, val);
1348 }
1349 
1350 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1351                                     unsigned int size)
1352 {
1353     SysBusESPState *sysbus = opaque;
1354     ESPState *s = ESP(&sysbus->esp);
1355     uint32_t saddr;
1356 
1357     saddr = addr >> sysbus->it_shift;
1358     return esp_reg_read(s, saddr);
1359 }
1360 
1361 static const MemoryRegionOps sysbus_esp_mem_ops = {
1362     .read = sysbus_esp_mem_read,
1363     .write = sysbus_esp_mem_write,
1364     .endianness = DEVICE_NATIVE_ENDIAN,
1365     .valid.accepts = esp_mem_accepts,
1366 };
1367 
1368 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1369                                   uint64_t val, unsigned int size)
1370 {
1371     SysBusESPState *sysbus = opaque;
1372     ESPState *s = ESP(&sysbus->esp);
1373 
1374     trace_esp_pdma_write(size);
1375 
1376     switch (size) {
1377     case 1:
1378         esp_pdma_write(s, val);
1379         break;
1380     case 2:
1381         esp_pdma_write(s, val >> 8);
1382         esp_pdma_write(s, val);
1383         break;
1384     }
1385     esp_pdma_cb(s);
1386 }
1387 
1388 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1389                                      unsigned int size)
1390 {
1391     SysBusESPState *sysbus = opaque;
1392     ESPState *s = ESP(&sysbus->esp);
1393     uint64_t val = 0;
1394 
1395     trace_esp_pdma_read(size);
1396 
1397     switch (size) {
1398     case 1:
1399         val = esp_pdma_read(s);
1400         break;
1401     case 2:
1402         val = esp_pdma_read(s);
1403         val = (val << 8) | esp_pdma_read(s);
1404         break;
1405     }
1406     esp_pdma_cb(s);
1407     return val;
1408 }
1409 
1410 static void *esp_load_request(QEMUFile *f, SCSIRequest *req)
1411 {
1412     ESPState *s = container_of(req->bus, ESPState, bus);
1413 
1414     scsi_req_ref(req);
1415     s->current_req = req;
1416     return s;
1417 }
1418 
1419 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1420     .read = sysbus_esp_pdma_read,
1421     .write = sysbus_esp_pdma_write,
1422     .endianness = DEVICE_NATIVE_ENDIAN,
1423     .valid.min_access_size = 1,
1424     .valid.max_access_size = 4,
1425     .impl.min_access_size = 1,
1426     .impl.max_access_size = 2,
1427 };
1428 
1429 static const struct SCSIBusInfo esp_scsi_info = {
1430     .tcq = false,
1431     .max_target = ESP_MAX_DEVS,
1432     .max_lun = 7,
1433 
1434     .load_request = esp_load_request,
1435     .transfer_data = esp_transfer_data,
1436     .complete = esp_command_complete,
1437     .cancel = esp_request_cancelled
1438 };
1439 
1440 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1441 {
1442     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1443     ESPState *s = ESP(&sysbus->esp);
1444 
1445     switch (irq) {
1446     case 0:
1447         parent_esp_reset(s, irq, level);
1448         break;
1449     case 1:
1450         esp_dma_enable(s, irq, level);
1451         break;
1452     }
1453 }
1454 
1455 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1456 {
1457     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1458     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1459     ESPState *s = ESP(&sysbus->esp);
1460 
1461     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1462         return;
1463     }
1464 
1465     sysbus_init_irq(sbd, &s->irq);
1466     sysbus_init_irq(sbd, &s->irq_data);
1467     assert(sysbus->it_shift != -1);
1468 
1469     s->chip_id = TCHI_FAS100A;
1470     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1471                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1472     sysbus_init_mmio(sbd, &sysbus->iomem);
1473     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1474                           sysbus, "esp-pdma", 4);
1475     sysbus_init_mmio(sbd, &sysbus->pdma);
1476 
1477     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1478 
1479     scsi_bus_init(&s->bus, sizeof(s->bus), dev, &esp_scsi_info);
1480 }
1481 
1482 static void sysbus_esp_hard_reset(DeviceState *dev)
1483 {
1484     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1485     ESPState *s = ESP(&sysbus->esp);
1486 
1487     esp_hard_reset(s);
1488 }
1489 
1490 static void sysbus_esp_init(Object *obj)
1491 {
1492     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1493 
1494     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1495 }
1496 
1497 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1498     .name = "sysbusespscsi",
1499     .version_id = 2,
1500     .minimum_version_id = 1,
1501     .pre_save = esp_pre_save,
1502     .fields = (const VMStateField[]) {
1503         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1504         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1505         VMSTATE_END_OF_LIST()
1506     }
1507 };
1508 
1509 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1510 {
1511     DeviceClass *dc = DEVICE_CLASS(klass);
1512 
1513     dc->realize = sysbus_esp_realize;
1514     dc->reset = sysbus_esp_hard_reset;
1515     dc->vmsd = &vmstate_sysbus_esp_scsi;
1516     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1517 }
1518 
1519 static const TypeInfo sysbus_esp_info = {
1520     .name          = TYPE_SYSBUS_ESP,
1521     .parent        = TYPE_SYS_BUS_DEVICE,
1522     .instance_init = sysbus_esp_init,
1523     .instance_size = sizeof(SysBusESPState),
1524     .class_init    = sysbus_esp_class_init,
1525 };
1526 
1527 static void esp_finalize(Object *obj)
1528 {
1529     ESPState *s = ESP(obj);
1530 
1531     fifo8_destroy(&s->fifo);
1532     fifo8_destroy(&s->cmdfifo);
1533 }
1534 
1535 static void esp_init(Object *obj)
1536 {
1537     ESPState *s = ESP(obj);
1538 
1539     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1540     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1541 }
1542 
1543 static void esp_class_init(ObjectClass *klass, void *data)
1544 {
1545     DeviceClass *dc = DEVICE_CLASS(klass);
1546 
1547     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1548     dc->user_creatable = false;
1549     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1550 }
1551 
1552 static const TypeInfo esp_info = {
1553     .name = TYPE_ESP,
1554     .parent = TYPE_DEVICE,
1555     .instance_init = esp_init,
1556     .instance_finalize = esp_finalize,
1557     .instance_size = sizeof(ESPState),
1558     .class_init = esp_class_init,
1559 };
1560 
1561 static void esp_register_types(void)
1562 {
1563     type_register_static(&sysbus_esp_info);
1564     type_register_static(&esp_info);
1565 }
1566 
1567 type_init(esp_register_types)
1568