xref: /qemu/hw/scsi/esp.c (revision 96676c2f749d9da99ee03ec0eee342bd7d09de26)
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     }
99 }
100 
101 static uint32_t esp_get_tc(ESPState *s)
102 {
103     uint32_t dmalen;
104 
105     dmalen = s->rregs[ESP_TCLO];
106     dmalen |= s->rregs[ESP_TCMID] << 8;
107     dmalen |= s->rregs[ESP_TCHI] << 16;
108 
109     return dmalen;
110 }
111 
112 static void esp_set_tc(ESPState *s, uint32_t dmalen)
113 {
114     s->rregs[ESP_TCLO] = dmalen;
115     s->rregs[ESP_TCMID] = dmalen >> 8;
116     s->rregs[ESP_TCHI] = dmalen >> 16;
117 }
118 
119 static uint32_t esp_get_stc(ESPState *s)
120 {
121     uint32_t dmalen;
122 
123     dmalen = s->wregs[ESP_TCLO];
124     dmalen |= s->wregs[ESP_TCMID] << 8;
125     dmalen |= s->wregs[ESP_TCHI] << 16;
126 
127     return dmalen;
128 }
129 
130 static void set_pdma(ESPState *s, enum pdma_origin_id origin,
131                      uint32_t index, uint32_t len)
132 {
133     s->pdma_origin = origin;
134     s->pdma_start = index;
135     s->pdma_cur = index;
136     s->pdma_len = len;
137 }
138 
139 static uint8_t *get_pdma_buf(ESPState *s)
140 {
141     switch (s->pdma_origin) {
142     case PDMA:
143         return s->pdma_buf;
144     case TI:
145         return s->ti_buf;
146     case CMD:
147         return s->cmdbuf;
148     case ASYNC:
149         return s->async_buf;
150     }
151     return NULL;
152 }
153 
154 static int get_cmd_cb(ESPState *s)
155 {
156     int target;
157 
158     target = s->wregs[ESP_WBUSID] & BUSID_DID;
159 
160     s->ti_size = 0;
161     s->ti_rptr = 0;
162     s->ti_wptr = 0;
163 
164     if (s->current_req) {
165         /* Started a new command before the old one finished.  Cancel it.  */
166         scsi_req_cancel(s->current_req);
167         s->async_len = 0;
168     }
169 
170     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
171     if (!s->current_dev) {
172         /* No such drive */
173         s->rregs[ESP_RSTAT] = 0;
174         s->rregs[ESP_RINTR] = INTR_DC;
175         s->rregs[ESP_RSEQ] = SEQ_0;
176         esp_raise_irq(s);
177         return -1;
178     }
179     return 0;
180 }
181 
182 static uint32_t get_cmd(ESPState *s, uint8_t *buf, uint8_t buflen)
183 {
184     uint32_t dmalen;
185     int target;
186 
187     target = s->wregs[ESP_WBUSID] & BUSID_DID;
188     if (s->dma) {
189         dmalen = esp_get_tc(s);
190         if (dmalen > buflen) {
191             return 0;
192         }
193         if (s->dma_memory_read) {
194             s->dma_memory_read(s->dma_opaque, buf, dmalen);
195         } else {
196             memcpy(s->pdma_buf, buf, dmalen);
197             set_pdma(s, PDMA, 0, dmalen);
198             esp_raise_drq(s);
199             return 0;
200         }
201     } else {
202         dmalen = s->ti_size;
203         if (dmalen > TI_BUFSZ) {
204             return 0;
205         }
206         memcpy(buf, s->ti_buf, dmalen);
207         buf[0] = buf[2] >> 5;
208     }
209     trace_esp_get_cmd(dmalen, target);
210 
211     if (get_cmd_cb(s) < 0) {
212         return 0;
213     }
214     return dmalen;
215 }
216 
217 static void do_busid_cmd(ESPState *s, uint8_t *buf, uint8_t busid)
218 {
219     int32_t datalen;
220     int lun;
221     SCSIDevice *current_lun;
222 
223     trace_esp_do_busid_cmd(busid);
224     lun = busid & 7;
225     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, lun);
226     s->current_req = scsi_req_new(current_lun, 0, lun, buf, s);
227     datalen = scsi_req_enqueue(s->current_req);
228     s->ti_size = datalen;
229     if (datalen != 0) {
230         s->rregs[ESP_RSTAT] = STAT_TC;
231         s->dma_left = 0;
232         s->dma_counter = 0;
233         if (datalen > 0) {
234             s->rregs[ESP_RSTAT] |= STAT_DI;
235         } else {
236             s->rregs[ESP_RSTAT] |= STAT_DO;
237         }
238         scsi_req_continue(s->current_req);
239     }
240     s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
241     s->rregs[ESP_RSEQ] = SEQ_CD;
242     esp_raise_irq(s);
243 }
244 
245 static void do_cmd(ESPState *s, uint8_t *buf)
246 {
247     uint8_t busid = buf[0];
248 
249     do_busid_cmd(s, &buf[1], busid);
250 }
251 
252 static void satn_pdma_cb(ESPState *s)
253 {
254     if (get_cmd_cb(s) < 0) {
255         return;
256     }
257     if (s->pdma_cur != s->pdma_start) {
258         do_cmd(s, get_pdma_buf(s) + s->pdma_start);
259     }
260 }
261 
262 static void handle_satn(ESPState *s)
263 {
264     uint8_t buf[32];
265     int len;
266 
267     if (s->dma && !s->dma_enabled) {
268         s->dma_cb = handle_satn;
269         return;
270     }
271     s->pdma_cb = satn_pdma_cb;
272     len = get_cmd(s, buf, sizeof(buf));
273     if (len) {
274         do_cmd(s, buf);
275     }
276 }
277 
278 static void s_without_satn_pdma_cb(ESPState *s)
279 {
280     if (get_cmd_cb(s) < 0) {
281         return;
282     }
283     if (s->pdma_cur != s->pdma_start) {
284         do_busid_cmd(s, get_pdma_buf(s) + s->pdma_start, 0);
285     }
286 }
287 
288 static void handle_s_without_atn(ESPState *s)
289 {
290     uint8_t buf[32];
291     int len;
292 
293     if (s->dma && !s->dma_enabled) {
294         s->dma_cb = handle_s_without_atn;
295         return;
296     }
297     s->pdma_cb = s_without_satn_pdma_cb;
298     len = get_cmd(s, buf, sizeof(buf));
299     if (len) {
300         do_busid_cmd(s, buf, 0);
301     }
302 }
303 
304 static void satn_stop_pdma_cb(ESPState *s)
305 {
306     if (get_cmd_cb(s) < 0) {
307         return;
308     }
309     s->cmdlen = s->pdma_cur - s->pdma_start;
310     if (s->cmdlen) {
311         trace_esp_handle_satn_stop(s->cmdlen);
312         s->do_cmd = 1;
313         s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
314         s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
315         s->rregs[ESP_RSEQ] = SEQ_CD;
316         esp_raise_irq(s);
317     }
318 }
319 
320 static void handle_satn_stop(ESPState *s)
321 {
322     if (s->dma && !s->dma_enabled) {
323         s->dma_cb = handle_satn_stop;
324         return;
325     }
326     s->pdma_cb = satn_stop_pdma_cb;
327     s->cmdlen = get_cmd(s, s->cmdbuf, sizeof(s->cmdbuf));
328     if (s->cmdlen) {
329         trace_esp_handle_satn_stop(s->cmdlen);
330         s->do_cmd = 1;
331         s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
332         s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
333         s->rregs[ESP_RSEQ] = SEQ_CD;
334         esp_raise_irq(s);
335     }
336 }
337 
338 static void write_response_pdma_cb(ESPState *s)
339 {
340     s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
341     s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
342     s->rregs[ESP_RSEQ] = SEQ_CD;
343     esp_raise_irq(s);
344 }
345 
346 static void write_response(ESPState *s)
347 {
348     trace_esp_write_response(s->status);
349     s->ti_buf[0] = s->status;
350     s->ti_buf[1] = 0;
351     if (s->dma) {
352         if (s->dma_memory_write) {
353             s->dma_memory_write(s->dma_opaque, s->ti_buf, 2);
354             s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
355             s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
356             s->rregs[ESP_RSEQ] = SEQ_CD;
357         } else {
358             set_pdma(s, TI, 0, 2);
359             s->pdma_cb = write_response_pdma_cb;
360             esp_raise_drq(s);
361             return;
362         }
363     } else {
364         s->ti_size = 2;
365         s->ti_rptr = 0;
366         s->ti_wptr = 2;
367         s->rregs[ESP_RFLAGS] = 2;
368     }
369     esp_raise_irq(s);
370 }
371 
372 static void esp_dma_done(ESPState *s)
373 {
374     s->rregs[ESP_RSTAT] |= STAT_TC;
375     s->rregs[ESP_RINTR] = INTR_BS;
376     s->rregs[ESP_RSEQ] = 0;
377     s->rregs[ESP_RFLAGS] = 0;
378     esp_set_tc(s, 0);
379     esp_raise_irq(s);
380 }
381 
382 static void do_dma_pdma_cb(ESPState *s)
383 {
384     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
385     int len = s->pdma_cur - s->pdma_start;
386     if (s->do_cmd) {
387         s->ti_size = 0;
388         s->cmdlen = 0;
389         s->do_cmd = 0;
390         do_cmd(s, s->cmdbuf);
391         return;
392     }
393     s->dma_left -= len;
394     s->async_buf += len;
395     s->async_len -= len;
396     if (to_device) {
397         s->ti_size += len;
398     } else {
399         s->ti_size -= len;
400     }
401     if (s->async_len == 0) {
402         scsi_req_continue(s->current_req);
403         /*
404          * If there is still data to be read from the device then
405          * complete the DMA operation immediately.  Otherwise defer
406          * until the scsi layer has completed.
407          */
408         if (to_device || s->dma_left != 0 || s->ti_size == 0) {
409             return;
410         }
411     }
412 
413     /* Partially filled a scsi buffer. Complete immediately.  */
414     esp_dma_done(s);
415 }
416 
417 static void esp_do_dma(ESPState *s)
418 {
419     uint32_t len;
420     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
421 
422     len = s->dma_left;
423     if (s->do_cmd) {
424         /*
425          * handle_ti_cmd() case: esp_do_dma() is called only from
426          * handle_ti_cmd() with do_cmd != NULL (see the assert())
427          */
428         trace_esp_do_dma(s->cmdlen, len);
429         assert(s->cmdlen <= sizeof(s->cmdbuf) &&
430                len <= sizeof(s->cmdbuf) - s->cmdlen);
431         if (s->dma_memory_read) {
432             s->dma_memory_read(s->dma_opaque, &s->cmdbuf[s->cmdlen], len);
433         } else {
434             set_pdma(s, CMD, s->cmdlen, len);
435             s->pdma_cb = do_dma_pdma_cb;
436             esp_raise_drq(s);
437             return;
438         }
439         trace_esp_handle_ti_cmd(s->cmdlen);
440         s->ti_size = 0;
441         s->cmdlen = 0;
442         s->do_cmd = 0;
443         do_cmd(s, s->cmdbuf);
444         return;
445     }
446     if (s->async_len == 0) {
447         /* Defer until data is available.  */
448         return;
449     }
450     if (len > s->async_len) {
451         len = s->async_len;
452     }
453     if (to_device) {
454         if (s->dma_memory_read) {
455             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
456         } else {
457             set_pdma(s, ASYNC, 0, len);
458             s->pdma_cb = do_dma_pdma_cb;
459             esp_raise_drq(s);
460             return;
461         }
462     } else {
463         if (s->dma_memory_write) {
464             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
465         } else {
466             set_pdma(s, ASYNC, 0, len);
467             s->pdma_cb = do_dma_pdma_cb;
468             esp_raise_drq(s);
469             return;
470         }
471     }
472     s->dma_left -= len;
473     s->async_buf += len;
474     s->async_len -= len;
475     if (to_device) {
476         s->ti_size += len;
477     } else {
478         s->ti_size -= len;
479     }
480     if (s->async_len == 0) {
481         scsi_req_continue(s->current_req);
482         /*
483          * If there is still data to be read from the device then
484          * complete the DMA operation immediately.  Otherwise defer
485          * until the scsi layer has completed.
486          */
487         if (to_device || s->dma_left != 0 || s->ti_size == 0) {
488             return;
489         }
490     }
491 
492     /* Partially filled a scsi buffer. Complete immediately.  */
493     esp_dma_done(s);
494 }
495 
496 static void esp_report_command_complete(ESPState *s, uint32_t status)
497 {
498     trace_esp_command_complete();
499     if (s->ti_size != 0) {
500         trace_esp_command_complete_unexpected();
501     }
502     s->ti_size = 0;
503     s->dma_left = 0;
504     s->async_len = 0;
505     if (status) {
506         trace_esp_command_complete_fail();
507     }
508     s->status = status;
509     s->rregs[ESP_RSTAT] = STAT_ST;
510     esp_dma_done(s);
511     if (s->current_req) {
512         scsi_req_unref(s->current_req);
513         s->current_req = NULL;
514         s->current_dev = NULL;
515     }
516 }
517 
518 void esp_command_complete(SCSIRequest *req, size_t resid)
519 {
520     ESPState *s = req->hba_private;
521 
522     if (s->rregs[ESP_RSTAT] & STAT_INT) {
523         /*
524          * Defer handling command complete until the previous
525          * interrupt has been handled.
526          */
527         trace_esp_command_complete_deferred();
528         s->deferred_status = req->status;
529         s->deferred_complete = true;
530         return;
531     }
532     esp_report_command_complete(s, req->status);
533 }
534 
535 void esp_transfer_data(SCSIRequest *req, uint32_t len)
536 {
537     ESPState *s = req->hba_private;
538 
539     assert(!s->do_cmd);
540     trace_esp_transfer_data(s->dma_left, s->ti_size);
541     s->async_len = len;
542     s->async_buf = scsi_req_get_buf(req);
543     if (s->dma_left) {
544         esp_do_dma(s);
545     } else if (s->dma_counter != 0 && s->ti_size <= 0) {
546         /*
547          * If this was the last part of a DMA transfer then the
548          * completion interrupt is deferred to here.
549          */
550         esp_dma_done(s);
551     }
552 }
553 
554 static void handle_ti(ESPState *s)
555 {
556     uint32_t dmalen, minlen;
557 
558     if (s->dma && !s->dma_enabled) {
559         s->dma_cb = handle_ti;
560         return;
561     }
562 
563     dmalen = esp_get_tc(s);
564     s->dma_counter = dmalen;
565 
566     if (s->do_cmd) {
567         minlen = (dmalen < ESP_CMDBUF_SZ) ? dmalen : ESP_CMDBUF_SZ;
568     } else if (s->ti_size < 0) {
569         minlen = (dmalen < -s->ti_size) ? dmalen : -s->ti_size;
570     } else {
571         minlen = (dmalen < s->ti_size) ? dmalen : s->ti_size;
572     }
573     trace_esp_handle_ti(minlen);
574     if (s->dma) {
575         s->dma_left = minlen;
576         s->rregs[ESP_RSTAT] &= ~STAT_TC;
577         esp_do_dma(s);
578     } else if (s->do_cmd) {
579         trace_esp_handle_ti_cmd(s->cmdlen);
580         s->ti_size = 0;
581         s->cmdlen = 0;
582         s->do_cmd = 0;
583         do_cmd(s, s->cmdbuf);
584     }
585 }
586 
587 void esp_hard_reset(ESPState *s)
588 {
589     memset(s->rregs, 0, ESP_REGS);
590     memset(s->wregs, 0, ESP_REGS);
591     s->tchi_written = 0;
592     s->ti_size = 0;
593     s->ti_rptr = 0;
594     s->ti_wptr = 0;
595     s->dma = 0;
596     s->do_cmd = 0;
597     s->dma_cb = NULL;
598 
599     s->rregs[ESP_CFG1] = 7;
600 }
601 
602 static void esp_soft_reset(ESPState *s)
603 {
604     qemu_irq_lower(s->irq);
605     qemu_irq_lower(s->irq_data);
606     esp_hard_reset(s);
607 }
608 
609 static void parent_esp_reset(ESPState *s, int irq, int level)
610 {
611     if (level) {
612         esp_soft_reset(s);
613     }
614 }
615 
616 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
617 {
618     uint32_t val;
619 
620     switch (saddr) {
621     case ESP_FIFO:
622         if ((s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
623             /* Data out.  */
624             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
625             s->rregs[ESP_FIFO] = 0;
626         } else if (s->ti_rptr < s->ti_wptr) {
627             s->ti_size--;
628             s->rregs[ESP_FIFO] = s->ti_buf[s->ti_rptr++];
629         }
630         if (s->ti_rptr == s->ti_wptr) {
631             s->ti_rptr = 0;
632             s->ti_wptr = 0;
633         }
634         val = s->rregs[ESP_FIFO];
635         break;
636     case ESP_RINTR:
637         /*
638          * Clear sequence step, interrupt register and all status bits
639          * except TC
640          */
641         val = s->rregs[ESP_RINTR];
642         s->rregs[ESP_RINTR] = 0;
643         s->rregs[ESP_RSTAT] &= ~STAT_TC;
644         s->rregs[ESP_RSEQ] = SEQ_CD;
645         esp_lower_irq(s);
646         if (s->deferred_complete) {
647             esp_report_command_complete(s, s->deferred_status);
648             s->deferred_complete = false;
649         }
650         break;
651     case ESP_TCHI:
652         /* Return the unique id if the value has never been written */
653         if (!s->tchi_written) {
654             val = s->chip_id;
655         } else {
656             val = s->rregs[saddr];
657         }
658         break;
659     default:
660         val = s->rregs[saddr];
661         break;
662     }
663 
664     trace_esp_mem_readb(saddr, val);
665     return val;
666 }
667 
668 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
669 {
670     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
671     switch (saddr) {
672     case ESP_TCHI:
673         s->tchi_written = true;
674         /* fall through */
675     case ESP_TCLO:
676     case ESP_TCMID:
677         s->rregs[ESP_RSTAT] &= ~STAT_TC;
678         break;
679     case ESP_FIFO:
680         if (s->do_cmd) {
681             if (s->cmdlen < ESP_CMDBUF_SZ) {
682                 s->cmdbuf[s->cmdlen++] = val & 0xff;
683             } else {
684                 trace_esp_error_fifo_overrun();
685             }
686         } else if (s->ti_wptr == TI_BUFSZ - 1) {
687             trace_esp_error_fifo_overrun();
688         } else {
689             s->ti_size++;
690             s->ti_buf[s->ti_wptr++] = val & 0xff;
691         }
692         break;
693     case ESP_CMD:
694         s->rregs[saddr] = val;
695         if (val & CMD_DMA) {
696             s->dma = 1;
697             /* Reload DMA counter.  */
698             if (esp_get_stc(s) == 0) {
699                 esp_set_tc(s, 0x10000);
700             } else {
701                 esp_set_tc(s, esp_get_stc(s));
702             }
703         } else {
704             s->dma = 0;
705         }
706         switch (val & CMD_CMD) {
707         case CMD_NOP:
708             trace_esp_mem_writeb_cmd_nop(val);
709             break;
710         case CMD_FLUSH:
711             trace_esp_mem_writeb_cmd_flush(val);
712             /*s->ti_size = 0;*/
713             s->rregs[ESP_RINTR] = INTR_FC;
714             s->rregs[ESP_RSEQ] = 0;
715             s->rregs[ESP_RFLAGS] = 0;
716             break;
717         case CMD_RESET:
718             trace_esp_mem_writeb_cmd_reset(val);
719             esp_soft_reset(s);
720             break;
721         case CMD_BUSRESET:
722             trace_esp_mem_writeb_cmd_bus_reset(val);
723             s->rregs[ESP_RINTR] = INTR_RST;
724             if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
725                 esp_raise_irq(s);
726             }
727             break;
728         case CMD_TI:
729             trace_esp_mem_writeb_cmd_ti(val);
730             handle_ti(s);
731             break;
732         case CMD_ICCS:
733             trace_esp_mem_writeb_cmd_iccs(val);
734             write_response(s);
735             s->rregs[ESP_RINTR] = INTR_FC;
736             s->rregs[ESP_RSTAT] |= STAT_MI;
737             break;
738         case CMD_MSGACC:
739             trace_esp_mem_writeb_cmd_msgacc(val);
740             s->rregs[ESP_RINTR] = INTR_DC;
741             s->rregs[ESP_RSEQ] = 0;
742             s->rregs[ESP_RFLAGS] = 0;
743             esp_raise_irq(s);
744             break;
745         case CMD_PAD:
746             trace_esp_mem_writeb_cmd_pad(val);
747             s->rregs[ESP_RSTAT] = STAT_TC;
748             s->rregs[ESP_RINTR] = INTR_FC;
749             s->rregs[ESP_RSEQ] = 0;
750             break;
751         case CMD_SATN:
752             trace_esp_mem_writeb_cmd_satn(val);
753             break;
754         case CMD_RSTATN:
755             trace_esp_mem_writeb_cmd_rstatn(val);
756             break;
757         case CMD_SEL:
758             trace_esp_mem_writeb_cmd_sel(val);
759             handle_s_without_atn(s);
760             break;
761         case CMD_SELATN:
762             trace_esp_mem_writeb_cmd_selatn(val);
763             handle_satn(s);
764             break;
765         case CMD_SELATNS:
766             trace_esp_mem_writeb_cmd_selatns(val);
767             handle_satn_stop(s);
768             break;
769         case CMD_ENSEL:
770             trace_esp_mem_writeb_cmd_ensel(val);
771             s->rregs[ESP_RINTR] = 0;
772             break;
773         case CMD_DISSEL:
774             trace_esp_mem_writeb_cmd_dissel(val);
775             s->rregs[ESP_RINTR] = 0;
776             esp_raise_irq(s);
777             break;
778         default:
779             trace_esp_error_unhandled_command(val);
780             break;
781         }
782         break;
783     case ESP_WBUSID ... ESP_WSYNO:
784         break;
785     case ESP_CFG1:
786     case ESP_CFG2: case ESP_CFG3:
787     case ESP_RES3: case ESP_RES4:
788         s->rregs[saddr] = val;
789         break;
790     case ESP_WCCF ... ESP_WTEST:
791         break;
792     default:
793         trace_esp_error_invalid_write(val, saddr);
794         return;
795     }
796     s->wregs[saddr] = val;
797 }
798 
799 static bool esp_mem_accepts(void *opaque, hwaddr addr,
800                             unsigned size, bool is_write,
801                             MemTxAttrs attrs)
802 {
803     return (size == 1) || (is_write && size == 4);
804 }
805 
806 static bool esp_pdma_needed(void *opaque)
807 {
808     ESPState *s = opaque;
809     return s->dma_memory_read == NULL && s->dma_memory_write == NULL &&
810            s->dma_enabled;
811 }
812 
813 static const VMStateDescription vmstate_esp_pdma = {
814     .name = "esp/pdma",
815     .version_id = 1,
816     .minimum_version_id = 1,
817     .needed = esp_pdma_needed,
818     .fields = (VMStateField[]) {
819         VMSTATE_BUFFER(pdma_buf, ESPState),
820         VMSTATE_INT32(pdma_origin, ESPState),
821         VMSTATE_UINT32(pdma_len, ESPState),
822         VMSTATE_UINT32(pdma_start, ESPState),
823         VMSTATE_UINT32(pdma_cur, ESPState),
824         VMSTATE_END_OF_LIST()
825     }
826 };
827 
828 static int esp_pre_save(void *opaque)
829 {
830     ESPState *s = ESP(opaque);
831 
832     s->mig_version_id = vmstate_esp.version_id;
833     return 0;
834 }
835 
836 static int esp_post_load(void *opaque, int version_id)
837 {
838     ESPState *s = ESP(opaque);
839 
840     s->mig_version_id = vmstate_esp.version_id;
841     return 0;
842 }
843 
844 const VMStateDescription vmstate_esp = {
845     .name = "esp",
846     .version_id = 5,
847     .minimum_version_id = 3,
848     .pre_save = esp_pre_save,
849     .post_load = esp_post_load,
850     .fields = (VMStateField[]) {
851         VMSTATE_BUFFER(rregs, ESPState),
852         VMSTATE_BUFFER(wregs, ESPState),
853         VMSTATE_INT32(ti_size, ESPState),
854         VMSTATE_UINT32(ti_rptr, ESPState),
855         VMSTATE_UINT32(ti_wptr, ESPState),
856         VMSTATE_BUFFER(ti_buf, ESPState),
857         VMSTATE_UINT32(status, ESPState),
858         VMSTATE_UINT32(deferred_status, ESPState),
859         VMSTATE_BOOL(deferred_complete, ESPState),
860         VMSTATE_UINT32(dma, ESPState),
861         VMSTATE_PARTIAL_BUFFER(cmdbuf, ESPState, 16),
862         VMSTATE_BUFFER_START_MIDDLE_V(cmdbuf, ESPState, 16, 4),
863         VMSTATE_UINT32(cmdlen, ESPState),
864         VMSTATE_UINT32(do_cmd, ESPState),
865         VMSTATE_UINT32(dma_left, ESPState),
866         VMSTATE_END_OF_LIST()
867     },
868     .subsections = (const VMStateDescription * []) {
869         &vmstate_esp_pdma,
870         NULL
871     }
872 };
873 
874 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
875                                  uint64_t val, unsigned int size)
876 {
877     SysBusESPState *sysbus = opaque;
878     ESPState *s = ESP(&sysbus->esp);
879     uint32_t saddr;
880 
881     saddr = addr >> sysbus->it_shift;
882     esp_reg_write(s, saddr, val);
883 }
884 
885 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
886                                     unsigned int size)
887 {
888     SysBusESPState *sysbus = opaque;
889     ESPState *s = ESP(&sysbus->esp);
890     uint32_t saddr;
891 
892     saddr = addr >> sysbus->it_shift;
893     return esp_reg_read(s, saddr);
894 }
895 
896 static const MemoryRegionOps sysbus_esp_mem_ops = {
897     .read = sysbus_esp_mem_read,
898     .write = sysbus_esp_mem_write,
899     .endianness = DEVICE_NATIVE_ENDIAN,
900     .valid.accepts = esp_mem_accepts,
901 };
902 
903 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
904                                   uint64_t val, unsigned int size)
905 {
906     SysBusESPState *sysbus = opaque;
907     ESPState *s = ESP(&sysbus->esp);
908     uint32_t dmalen;
909     uint8_t *buf = get_pdma_buf(s);
910 
911     trace_esp_pdma_write(size);
912 
913     dmalen = esp_get_tc(s);
914     if (dmalen == 0 || s->pdma_len == 0) {
915         return;
916     }
917     switch (size) {
918     case 1:
919         buf[s->pdma_cur++] = val;
920         s->pdma_len--;
921         dmalen--;
922         break;
923     case 2:
924         buf[s->pdma_cur++] = val >> 8;
925         buf[s->pdma_cur++] = val;
926         s->pdma_len -= 2;
927         dmalen -= 2;
928         break;
929     }
930     esp_set_tc(s, dmalen);
931     if (s->pdma_len == 0 && s->pdma_cb) {
932         esp_lower_drq(s);
933         s->pdma_cb(s);
934         s->pdma_cb = NULL;
935     }
936 }
937 
938 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
939                                      unsigned int size)
940 {
941     SysBusESPState *sysbus = opaque;
942     ESPState *s = ESP(&sysbus->esp);
943     uint8_t *buf = get_pdma_buf(s);
944     uint64_t val = 0;
945 
946     trace_esp_pdma_read(size);
947 
948     if (s->pdma_len == 0) {
949         return 0;
950     }
951     switch (size) {
952     case 1:
953         val = buf[s->pdma_cur++];
954         s->pdma_len--;
955         break;
956     case 2:
957         val = buf[s->pdma_cur++];
958         val = (val << 8) | buf[s->pdma_cur++];
959         s->pdma_len -= 2;
960         break;
961     }
962 
963     if (s->pdma_len == 0 && s->pdma_cb) {
964         esp_lower_drq(s);
965         s->pdma_cb(s);
966         s->pdma_cb = NULL;
967     }
968     return val;
969 }
970 
971 static const MemoryRegionOps sysbus_esp_pdma_ops = {
972     .read = sysbus_esp_pdma_read,
973     .write = sysbus_esp_pdma_write,
974     .endianness = DEVICE_NATIVE_ENDIAN,
975     .valid.min_access_size = 1,
976     .valid.max_access_size = 2,
977 };
978 
979 static const struct SCSIBusInfo esp_scsi_info = {
980     .tcq = false,
981     .max_target = ESP_MAX_DEVS,
982     .max_lun = 7,
983 
984     .transfer_data = esp_transfer_data,
985     .complete = esp_command_complete,
986     .cancel = esp_request_cancelled
987 };
988 
989 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
990 {
991     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
992     ESPState *s = ESP(&sysbus->esp);
993 
994     switch (irq) {
995     case 0:
996         parent_esp_reset(s, irq, level);
997         break;
998     case 1:
999         esp_dma_enable(opaque, irq, level);
1000         break;
1001     }
1002 }
1003 
1004 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1005 {
1006     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1007     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1008     ESPState *s = ESP(&sysbus->esp);
1009 
1010     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1011         return;
1012     }
1013 
1014     sysbus_init_irq(sbd, &s->irq);
1015     sysbus_init_irq(sbd, &s->irq_data);
1016     assert(sysbus->it_shift != -1);
1017 
1018     s->chip_id = TCHI_FAS100A;
1019     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1020                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1021     sysbus_init_mmio(sbd, &sysbus->iomem);
1022     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1023                           sysbus, "esp-pdma", 2);
1024     sysbus_init_mmio(sbd, &sysbus->pdma);
1025 
1026     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1027 
1028     scsi_bus_new(&s->bus, sizeof(s->bus), dev, &esp_scsi_info, NULL);
1029 }
1030 
1031 static void sysbus_esp_hard_reset(DeviceState *dev)
1032 {
1033     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1034     ESPState *s = ESP(&sysbus->esp);
1035 
1036     esp_hard_reset(s);
1037 }
1038 
1039 static void sysbus_esp_init(Object *obj)
1040 {
1041     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1042 
1043     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1044 }
1045 
1046 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1047     .name = "sysbusespscsi",
1048     .version_id = 2,
1049     .minimum_version_id = 1,
1050     .fields = (VMStateField[]) {
1051         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1052         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1053         VMSTATE_END_OF_LIST()
1054     }
1055 };
1056 
1057 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1058 {
1059     DeviceClass *dc = DEVICE_CLASS(klass);
1060 
1061     dc->realize = sysbus_esp_realize;
1062     dc->reset = sysbus_esp_hard_reset;
1063     dc->vmsd = &vmstate_sysbus_esp_scsi;
1064     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1065 }
1066 
1067 static const TypeInfo sysbus_esp_info = {
1068     .name          = TYPE_SYSBUS_ESP,
1069     .parent        = TYPE_SYS_BUS_DEVICE,
1070     .instance_init = sysbus_esp_init,
1071     .instance_size = sizeof(SysBusESPState),
1072     .class_init    = sysbus_esp_class_init,
1073 };
1074 
1075 static void esp_class_init(ObjectClass *klass, void *data)
1076 {
1077     DeviceClass *dc = DEVICE_CLASS(klass);
1078 
1079     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1080     dc->user_creatable = false;
1081     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1082 }
1083 
1084 static const TypeInfo esp_info = {
1085     .name = TYPE_ESP,
1086     .parent = TYPE_DEVICE,
1087     .instance_size = sizeof(ESPState),
1088     .class_init = esp_class_init,
1089 };
1090 
1091 static void esp_register_types(void)
1092 {
1093     type_register_static(&sysbus_esp_info);
1094     type_register_static(&esp_info);
1095 }
1096 
1097 type_init(esp_register_types)
1098