xref: /qemu/hw/scsi/esp.c (revision 1b9e48a5bdbc96833113f249909af0d30a76cc25)
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 void esp_fifo_push(ESPState *s, uint8_t val)
102 {
103     if (fifo8_num_used(&s->fifo) == ESP_FIFO_SZ) {
104         trace_esp_error_fifo_overrun();
105         return;
106     }
107 
108     fifo8_push(&s->fifo, val);
109 }
110 
111 static uint8_t esp_fifo_pop(ESPState *s)
112 {
113     if (fifo8_is_empty(&s->fifo)) {
114         return 0;
115     }
116 
117     return fifo8_pop(&s->fifo);
118 }
119 
120 static void esp_cmdfifo_push(ESPState *s, uint8_t val)
121 {
122     if (fifo8_num_used(&s->cmdfifo) == ESP_CMDFIFO_SZ) {
123         trace_esp_error_fifo_overrun();
124         return;
125     }
126 
127     fifo8_push(&s->cmdfifo, val);
128 }
129 
130 static uint8_t esp_cmdfifo_pop(ESPState *s)
131 {
132     if (fifo8_is_empty(&s->cmdfifo)) {
133         return 0;
134     }
135 
136     return fifo8_pop(&s->cmdfifo);
137 }
138 
139 static uint32_t esp_get_tc(ESPState *s)
140 {
141     uint32_t dmalen;
142 
143     dmalen = s->rregs[ESP_TCLO];
144     dmalen |= s->rregs[ESP_TCMID] << 8;
145     dmalen |= s->rregs[ESP_TCHI] << 16;
146 
147     return dmalen;
148 }
149 
150 static void esp_set_tc(ESPState *s, uint32_t dmalen)
151 {
152     s->rregs[ESP_TCLO] = dmalen;
153     s->rregs[ESP_TCMID] = dmalen >> 8;
154     s->rregs[ESP_TCHI] = dmalen >> 16;
155 }
156 
157 static uint32_t esp_get_stc(ESPState *s)
158 {
159     uint32_t dmalen;
160 
161     dmalen = s->wregs[ESP_TCLO];
162     dmalen |= s->wregs[ESP_TCMID] << 8;
163     dmalen |= s->wregs[ESP_TCHI] << 16;
164 
165     return dmalen;
166 }
167 
168 static uint8_t esp_pdma_read(ESPState *s)
169 {
170     uint8_t val;
171 
172     if (s->do_cmd) {
173         val = esp_cmdfifo_pop(s);
174     } else {
175         val = esp_fifo_pop(s);
176     }
177 
178     return val;
179 }
180 
181 static void esp_pdma_write(ESPState *s, uint8_t val)
182 {
183     uint32_t dmalen = esp_get_tc(s);
184 
185     if (dmalen == 0) {
186         return;
187     }
188 
189     if (s->do_cmd) {
190         esp_cmdfifo_push(s, val);
191     } else {
192         esp_fifo_push(s, val);
193     }
194 
195     dmalen--;
196     esp_set_tc(s, dmalen);
197 }
198 
199 static int esp_select(ESPState *s)
200 {
201     int target;
202 
203     target = s->wregs[ESP_WBUSID] & BUSID_DID;
204 
205     s->ti_size = 0;
206     fifo8_reset(&s->fifo);
207 
208     if (s->current_req) {
209         /* Started a new command before the old one finished.  Cancel it.  */
210         scsi_req_cancel(s->current_req);
211         s->async_len = 0;
212     }
213 
214     s->current_dev = scsi_device_find(&s->bus, 0, target, 0);
215     if (!s->current_dev) {
216         /* No such drive */
217         s->rregs[ESP_RSTAT] = 0;
218         s->rregs[ESP_RINTR] |= INTR_DC;
219         s->rregs[ESP_RSEQ] = SEQ_0;
220         esp_raise_irq(s);
221         return -1;
222     }
223 
224     /*
225      * Note that we deliberately don't raise the IRQ here: this will be done
226      * either in do_busid_cmd() for DATA OUT transfers or by the deferred
227      * IRQ mechanism in esp_transfer_data() for DATA IN transfers
228      */
229     s->rregs[ESP_RINTR] |= INTR_FC;
230     s->rregs[ESP_RSEQ] = SEQ_CD;
231     return 0;
232 }
233 
234 static uint32_t get_cmd(ESPState *s, uint32_t maxlen)
235 {
236     uint8_t buf[ESP_CMDFIFO_SZ];
237     uint32_t dmalen, n;
238     int target;
239 
240     target = s->wregs[ESP_WBUSID] & BUSID_DID;
241     if (s->dma) {
242         dmalen = MIN(esp_get_tc(s), maxlen);
243         if (dmalen == 0) {
244             return 0;
245         }
246         if (s->dma_memory_read) {
247             s->dma_memory_read(s->dma_opaque, buf, dmalen);
248             fifo8_push_all(&s->cmdfifo, buf, dmalen);
249         } else {
250             if (esp_select(s) < 0) {
251                 fifo8_reset(&s->cmdfifo);
252                 return -1;
253             }
254             esp_raise_drq(s);
255             fifo8_reset(&s->cmdfifo);
256             return 0;
257         }
258     } else {
259         dmalen = MIN(fifo8_num_used(&s->fifo), maxlen);
260         if (dmalen == 0) {
261             return 0;
262         }
263         memcpy(buf, fifo8_pop_buf(&s->fifo, dmalen, &n), dmalen);
264         if (dmalen >= 3) {
265             buf[0] = buf[2] >> 5;
266         }
267         fifo8_push_all(&s->cmdfifo, buf, dmalen);
268     }
269     trace_esp_get_cmd(dmalen, target);
270 
271     if (esp_select(s) < 0) {
272         fifo8_reset(&s->cmdfifo);
273         return -1;
274     }
275     return dmalen;
276 }
277 
278 static void do_busid_cmd(ESPState *s, uint8_t busid)
279 {
280     uint32_t n, cmdlen;
281     int32_t datalen;
282     int lun;
283     SCSIDevice *current_lun;
284     uint8_t *buf;
285 
286     trace_esp_do_busid_cmd(busid);
287     lun = busid & 7;
288     cmdlen = fifo8_num_used(&s->cmdfifo);
289     buf = (uint8_t *)fifo8_pop_buf(&s->cmdfifo, cmdlen, &n);
290 
291     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, lun);
292     s->current_req = scsi_req_new(current_lun, 0, lun, buf, s);
293     datalen = scsi_req_enqueue(s->current_req);
294     s->ti_size = datalen;
295     fifo8_reset(&s->cmdfifo);
296     if (datalen != 0) {
297         s->rregs[ESP_RSTAT] = STAT_TC;
298         s->rregs[ESP_RSEQ] = SEQ_CD;
299         s->ti_cmd = 0;
300         esp_set_tc(s, 0);
301         if (datalen > 0) {
302             /*
303              * Switch to DATA IN phase but wait until initial data xfer is
304              * complete before raising the command completion interrupt
305              */
306             s->data_in_ready = false;
307             s->rregs[ESP_RSTAT] |= STAT_DI;
308         } else {
309             s->rregs[ESP_RSTAT] |= STAT_DO;
310             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
311             esp_raise_irq(s);
312             esp_lower_drq(s);
313         }
314         scsi_req_continue(s->current_req);
315         return;
316     }
317 }
318 
319 static void do_cmd(ESPState *s)
320 {
321     uint8_t busid = fifo8_pop(&s->cmdfifo);
322     uint32_t n;
323 
324     s->cmdfifo_cdb_offset--;
325 
326     /* Ignore extended messages for now */
327     if (s->cmdfifo_cdb_offset) {
328         fifo8_pop_buf(&s->cmdfifo, s->cmdfifo_cdb_offset, &n);
329         s->cmdfifo_cdb_offset = 0;
330     }
331 
332     do_busid_cmd(s, busid);
333 }
334 
335 static void satn_pdma_cb(ESPState *s)
336 {
337     s->do_cmd = 0;
338     if (!fifo8_is_empty(&s->cmdfifo)) {
339         s->cmdfifo_cdb_offset = 1;
340         do_cmd(s);
341     }
342 }
343 
344 static void handle_satn(ESPState *s)
345 {
346     int32_t cmdlen;
347 
348     if (s->dma && !s->dma_enabled) {
349         s->dma_cb = handle_satn;
350         return;
351     }
352     s->pdma_cb = satn_pdma_cb;
353     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
354     if (cmdlen > 0) {
355         s->cmdfifo_cdb_offset = 1;
356         do_cmd(s);
357     } else if (cmdlen == 0) {
358         s->do_cmd = 1;
359         /* Target present, but no cmd yet - switch to command phase */
360         s->rregs[ESP_RSEQ] = SEQ_CD;
361         s->rregs[ESP_RSTAT] = STAT_CD;
362     }
363 }
364 
365 static void s_without_satn_pdma_cb(ESPState *s)
366 {
367     uint32_t len;
368 
369     s->do_cmd = 0;
370     len = fifo8_num_used(&s->cmdfifo);
371     if (len) {
372         s->cmdfifo_cdb_offset = 0;
373         do_busid_cmd(s, 0);
374     }
375 }
376 
377 static void handle_s_without_atn(ESPState *s)
378 {
379     int32_t cmdlen;
380 
381     if (s->dma && !s->dma_enabled) {
382         s->dma_cb = handle_s_without_atn;
383         return;
384     }
385     s->pdma_cb = s_without_satn_pdma_cb;
386     cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
387     if (cmdlen > 0) {
388         s->cmdfifo_cdb_offset = 0;
389         do_busid_cmd(s, 0);
390     } else if (cmdlen == 0) {
391         s->do_cmd = 1;
392         /* Target present, but no cmd yet - switch to command phase */
393         s->rregs[ESP_RSEQ] = SEQ_CD;
394         s->rregs[ESP_RSTAT] = STAT_CD;
395     }
396 }
397 
398 static void satn_stop_pdma_cb(ESPState *s)
399 {
400     s->do_cmd = 0;
401     if (!fifo8_is_empty(&s->cmdfifo)) {
402         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
403         s->do_cmd = 1;
404         s->cmdfifo_cdb_offset = 1;
405         s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
406         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
407         s->rregs[ESP_RSEQ] = SEQ_CD;
408         esp_raise_irq(s);
409     }
410 }
411 
412 static void handle_satn_stop(ESPState *s)
413 {
414     int32_t cmdlen;
415 
416     if (s->dma && !s->dma_enabled) {
417         s->dma_cb = handle_satn_stop;
418         return;
419     }
420     s->pdma_cb = satn_stop_pdma_cb;
421     cmdlen = get_cmd(s, 1);
422     if (cmdlen > 0) {
423         trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo));
424         s->do_cmd = 1;
425         s->cmdfifo_cdb_offset = 1;
426         s->rregs[ESP_RSTAT] = STAT_MO;
427         s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
428         s->rregs[ESP_RSEQ] = SEQ_MO;
429         esp_raise_irq(s);
430     } else if (cmdlen == 0) {
431         s->do_cmd = 1;
432         /* Target present, switch to message out phase */
433         s->rregs[ESP_RSEQ] = SEQ_MO;
434         s->rregs[ESP_RSTAT] = STAT_MO;
435     }
436 }
437 
438 static void write_response_pdma_cb(ESPState *s)
439 {
440     s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
441     s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
442     s->rregs[ESP_RSEQ] = SEQ_CD;
443     esp_raise_irq(s);
444 }
445 
446 static void write_response(ESPState *s)
447 {
448     uint32_t n;
449 
450     trace_esp_write_response(s->status);
451 
452     fifo8_reset(&s->fifo);
453     esp_fifo_push(s, s->status);
454     esp_fifo_push(s, 0);
455 
456     if (s->dma) {
457         if (s->dma_memory_write) {
458             s->dma_memory_write(s->dma_opaque,
459                                 (uint8_t *)fifo8_pop_buf(&s->fifo, 2, &n), 2);
460             s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
461             s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
462             s->rregs[ESP_RSEQ] = SEQ_CD;
463         } else {
464             s->pdma_cb = write_response_pdma_cb;
465             esp_raise_drq(s);
466             return;
467         }
468     } else {
469         s->ti_size = 2;
470         s->rregs[ESP_RFLAGS] = 2;
471     }
472     esp_raise_irq(s);
473 }
474 
475 static void esp_dma_done(ESPState *s)
476 {
477     s->rregs[ESP_RSTAT] |= STAT_TC;
478     s->rregs[ESP_RINTR] |= INTR_BS;
479     s->rregs[ESP_RSEQ] = 0;
480     s->rregs[ESP_RFLAGS] = 0;
481     esp_set_tc(s, 0);
482     esp_raise_irq(s);
483 }
484 
485 static void do_dma_pdma_cb(ESPState *s)
486 {
487     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
488     int len;
489     uint32_t n;
490 
491     if (s->do_cmd) {
492         s->ti_size = 0;
493         s->do_cmd = 0;
494         do_cmd(s);
495         esp_lower_drq(s);
496         return;
497     }
498 
499     if (to_device) {
500         /* Copy FIFO data to device */
501         len = MIN(fifo8_num_used(&s->fifo), ESP_FIFO_SZ);
502         memcpy(s->async_buf, fifo8_pop_buf(&s->fifo, len, &n), len);
503         s->async_buf += len;
504         s->async_len -= len;
505         s->ti_size += len;
506         if (s->async_len == 0) {
507             scsi_req_continue(s->current_req);
508             return;
509         }
510 
511         if (esp_get_tc(s) == 0) {
512             esp_lower_drq(s);
513             esp_dma_done(s);
514         }
515 
516         return;
517     } else {
518         if (s->async_len == 0) {
519             if (s->current_req) {
520                 /* Defer until the scsi layer has completed */
521                 scsi_req_continue(s->current_req);
522                 s->data_in_ready = false;
523             }
524             return;
525         }
526 
527         if (esp_get_tc(s) != 0) {
528             /* Copy device data to FIFO */
529             len = MIN(s->async_len, fifo8_num_free(&s->fifo));
530             fifo8_push_all(&s->fifo, s->async_buf, len);
531             s->async_buf += len;
532             s->async_len -= len;
533             s->ti_size -= len;
534             esp_set_tc(s, esp_get_tc(s) - len);
535             return;
536         }
537 
538         /* Partially filled a scsi buffer. Complete immediately.  */
539         esp_lower_drq(s);
540         esp_dma_done(s);
541     }
542 }
543 
544 static void esp_do_dma(ESPState *s)
545 {
546     uint32_t len, cmdlen;
547     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
548     uint8_t buf[ESP_CMDFIFO_SZ];
549 
550     len = esp_get_tc(s);
551     if (s->do_cmd) {
552         /*
553          * handle_ti_cmd() case: esp_do_dma() is called only from
554          * handle_ti_cmd() with do_cmd != NULL (see the assert())
555          */
556         cmdlen = fifo8_num_used(&s->cmdfifo);
557         trace_esp_do_dma(cmdlen, len);
558         if (s->dma_memory_read) {
559             s->dma_memory_read(s->dma_opaque, buf, len);
560             fifo8_push_all(&s->cmdfifo, buf, len);
561         } else {
562             s->pdma_cb = do_dma_pdma_cb;
563             esp_raise_drq(s);
564             return;
565         }
566         trace_esp_handle_ti_cmd(cmdlen);
567         s->ti_size = 0;
568         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
569             /* No command received */
570             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
571                 return;
572             }
573 
574             /* Command has been received */
575             s->do_cmd = 0;
576             do_cmd(s);
577         } else {
578             /*
579              * Extra message out bytes received: update cmdfifo_cdb_offset
580              * and then switch to commmand phase
581              */
582             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
583             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
584             s->rregs[ESP_RSEQ] = SEQ_CD;
585             s->rregs[ESP_RINTR] |= INTR_BS;
586             esp_raise_irq(s);
587         }
588         return;
589     }
590     if (s->async_len == 0) {
591         /* Defer until data is available.  */
592         return;
593     }
594     if (len > s->async_len) {
595         len = s->async_len;
596     }
597     if (to_device) {
598         if (s->dma_memory_read) {
599             s->dma_memory_read(s->dma_opaque, s->async_buf, len);
600         } else {
601             s->pdma_cb = do_dma_pdma_cb;
602             esp_raise_drq(s);
603             return;
604         }
605     } else {
606         if (s->dma_memory_write) {
607             s->dma_memory_write(s->dma_opaque, s->async_buf, len);
608         } else {
609             /* Copy device data to FIFO */
610             len = MIN(len, fifo8_num_free(&s->fifo));
611             fifo8_push_all(&s->fifo, s->async_buf, len);
612             s->async_buf += len;
613             s->async_len -= len;
614             s->ti_size -= len;
615             esp_set_tc(s, esp_get_tc(s) - len);
616             s->pdma_cb = do_dma_pdma_cb;
617             esp_raise_drq(s);
618 
619             /* Indicate transfer to FIFO is complete */
620             s->rregs[ESP_RSTAT] |= STAT_TC;
621             return;
622         }
623     }
624     esp_set_tc(s, esp_get_tc(s) - len);
625     s->async_buf += len;
626     s->async_len -= len;
627     if (to_device) {
628         s->ti_size += len;
629     } else {
630         s->ti_size -= len;
631     }
632     if (s->async_len == 0) {
633         scsi_req_continue(s->current_req);
634         /*
635          * If there is still data to be read from the device then
636          * complete the DMA operation immediately.  Otherwise defer
637          * until the scsi layer has completed.
638          */
639         if (to_device || esp_get_tc(s) != 0 || s->ti_size == 0) {
640             return;
641         }
642     }
643 
644     /* Partially filled a scsi buffer. Complete immediately.  */
645     esp_dma_done(s);
646     esp_lower_drq(s);
647 }
648 
649 static void esp_do_nodma(ESPState *s)
650 {
651     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
652     uint32_t cmdlen, n;
653     int len;
654 
655     if (s->do_cmd) {
656         cmdlen = fifo8_num_used(&s->cmdfifo);
657         trace_esp_handle_ti_cmd(cmdlen);
658         s->ti_size = 0;
659         if ((s->rregs[ESP_RSTAT] & 7) == STAT_CD) {
660             /* No command received */
661             if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
662                 return;
663             }
664 
665             /* Command has been received */
666             s->do_cmd = 0;
667             do_cmd(s);
668         } else {
669             /*
670              * Extra message out bytes received: update cmdfifo_cdb_offset
671              * and then switch to commmand phase
672              */
673             s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
674             s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;
675             s->rregs[ESP_RSEQ] = SEQ_CD;
676             s->rregs[ESP_RINTR] |= INTR_BS;
677             esp_raise_irq(s);
678         }
679         return;
680     }
681 
682     if (s->async_len == 0) {
683         /* Defer until data is available.  */
684         return;
685     }
686 
687     if (to_device) {
688         len = MIN(fifo8_num_used(&s->fifo), ESP_FIFO_SZ);
689         memcpy(s->async_buf, fifo8_pop_buf(&s->fifo, len, &n), len);
690         s->async_buf += len;
691         s->async_len -= len;
692         s->ti_size += len;
693     } else {
694         len = MIN(s->ti_size, s->async_len);
695         len = MIN(len, fifo8_num_free(&s->fifo));
696         fifo8_push_all(&s->fifo, s->async_buf, len);
697         s->async_buf += len;
698         s->async_len -= len;
699         s->ti_size -= len;
700     }
701 
702     if (s->async_len == 0) {
703         scsi_req_continue(s->current_req);
704 
705         if (to_device || s->ti_size == 0) {
706             return;
707         }
708     }
709 
710     s->rregs[ESP_RINTR] |= INTR_BS;
711     esp_raise_irq(s);
712 }
713 
714 void esp_command_complete(SCSIRequest *req, size_t resid)
715 {
716     ESPState *s = req->hba_private;
717 
718     trace_esp_command_complete();
719     if (s->ti_size != 0) {
720         trace_esp_command_complete_unexpected();
721     }
722     s->ti_size = 0;
723     s->async_len = 0;
724     if (req->status) {
725         trace_esp_command_complete_fail();
726     }
727     s->status = req->status;
728     s->rregs[ESP_RSTAT] = STAT_ST;
729     esp_dma_done(s);
730     esp_lower_drq(s);
731     if (s->current_req) {
732         scsi_req_unref(s->current_req);
733         s->current_req = NULL;
734         s->current_dev = NULL;
735     }
736 }
737 
738 void esp_transfer_data(SCSIRequest *req, uint32_t len)
739 {
740     ESPState *s = req->hba_private;
741     int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
742     uint32_t dmalen = esp_get_tc(s);
743 
744     assert(!s->do_cmd);
745     trace_esp_transfer_data(dmalen, s->ti_size);
746     s->async_len = len;
747     s->async_buf = scsi_req_get_buf(req);
748 
749     if (!to_device && !s->data_in_ready) {
750         /*
751          * Initial incoming data xfer is complete so raise command
752          * completion interrupt
753          */
754         s->data_in_ready = true;
755         s->rregs[ESP_RSTAT] |= STAT_TC;
756         s->rregs[ESP_RINTR] |= INTR_BS;
757         esp_raise_irq(s);
758 
759         /*
760          * If data is ready to transfer and the TI command has already
761          * been executed, start DMA immediately. Otherwise DMA will start
762          * when host sends the TI command
763          */
764         if (s->ti_size && (s->rregs[ESP_CMD] == (CMD_TI | CMD_DMA))) {
765             esp_do_dma(s);
766         }
767         return;
768     }
769 
770     if (s->ti_cmd == 0) {
771         /*
772          * Always perform the initial transfer upon reception of the next TI
773          * command to ensure the DMA/non-DMA status of the command is correct.
774          * It is not possible to use s->dma directly in the section below as
775          * some OSs send non-DMA NOP commands after a DMA transfer. Hence if the
776          * async data transfer is delayed then s->dma is set incorrectly.
777          */
778         return;
779     }
780 
781     if (s->ti_cmd & CMD_DMA) {
782         if (dmalen) {
783             esp_do_dma(s);
784         } else if (s->ti_size <= 0) {
785             /*
786              * If this was the last part of a DMA transfer then the
787              * completion interrupt is deferred to here.
788              */
789             esp_dma_done(s);
790             esp_lower_drq(s);
791         }
792     } else {
793         esp_do_nodma(s);
794     }
795 }
796 
797 static void handle_ti(ESPState *s)
798 {
799     uint32_t dmalen;
800 
801     if (s->dma && !s->dma_enabled) {
802         s->dma_cb = handle_ti;
803         return;
804     }
805 
806     s->ti_cmd = s->rregs[ESP_CMD];
807     if (s->dma) {
808         dmalen = esp_get_tc(s);
809         trace_esp_handle_ti(dmalen);
810         s->rregs[ESP_RSTAT] &= ~STAT_TC;
811         esp_do_dma(s);
812     } else {
813         trace_esp_handle_ti(s->ti_size);
814         esp_do_nodma(s);
815     }
816 }
817 
818 void esp_hard_reset(ESPState *s)
819 {
820     memset(s->rregs, 0, ESP_REGS);
821     memset(s->wregs, 0, ESP_REGS);
822     s->tchi_written = 0;
823     s->ti_size = 0;
824     fifo8_reset(&s->fifo);
825     fifo8_reset(&s->cmdfifo);
826     s->dma = 0;
827     s->do_cmd = 0;
828     s->dma_cb = NULL;
829 
830     s->rregs[ESP_CFG1] = 7;
831 }
832 
833 static void esp_soft_reset(ESPState *s)
834 {
835     qemu_irq_lower(s->irq);
836     qemu_irq_lower(s->irq_data);
837     esp_hard_reset(s);
838 }
839 
840 static void parent_esp_reset(ESPState *s, int irq, int level)
841 {
842     if (level) {
843         esp_soft_reset(s);
844     }
845 }
846 
847 uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
848 {
849     uint32_t val;
850 
851     switch (saddr) {
852     case ESP_FIFO:
853         if (s->dma_memory_read && s->dma_memory_write &&
854                 (s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
855             /* Data out.  */
856             qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
857             s->rregs[ESP_FIFO] = 0;
858         } else {
859             s->rregs[ESP_FIFO] = esp_fifo_pop(s);
860         }
861         val = s->rregs[ESP_FIFO];
862         break;
863     case ESP_RINTR:
864         /*
865          * Clear sequence step, interrupt register and all status bits
866          * except TC
867          */
868         val = s->rregs[ESP_RINTR];
869         s->rregs[ESP_RINTR] = 0;
870         s->rregs[ESP_RSTAT] &= ~STAT_TC;
871         s->rregs[ESP_RSEQ] = SEQ_0;
872         esp_lower_irq(s);
873         break;
874     case ESP_TCHI:
875         /* Return the unique id if the value has never been written */
876         if (!s->tchi_written) {
877             val = s->chip_id;
878         } else {
879             val = s->rregs[saddr];
880         }
881         break;
882      case ESP_RFLAGS:
883         /* Bottom 5 bits indicate number of bytes in FIFO */
884         val = fifo8_num_used(&s->fifo);
885         break;
886     default:
887         val = s->rregs[saddr];
888         break;
889     }
890 
891     trace_esp_mem_readb(saddr, val);
892     return val;
893 }
894 
895 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
896 {
897     trace_esp_mem_writeb(saddr, s->wregs[saddr], val);
898     switch (saddr) {
899     case ESP_TCHI:
900         s->tchi_written = true;
901         /* fall through */
902     case ESP_TCLO:
903     case ESP_TCMID:
904         s->rregs[ESP_RSTAT] &= ~STAT_TC;
905         break;
906     case ESP_FIFO:
907         if (s->do_cmd) {
908             esp_cmdfifo_push(s, val);
909         } else {
910             esp_fifo_push(s, val);
911         }
912 
913         /* Non-DMA transfers raise an interrupt after every byte */
914         if (s->rregs[ESP_CMD] == CMD_TI) {
915             s->rregs[ESP_RINTR] |= INTR_FC | INTR_BS;
916             esp_raise_irq(s);
917         }
918         break;
919     case ESP_CMD:
920         s->rregs[saddr] = val;
921         if (val & CMD_DMA) {
922             s->dma = 1;
923             /* Reload DMA counter.  */
924             if (esp_get_stc(s) == 0) {
925                 esp_set_tc(s, 0x10000);
926             } else {
927                 esp_set_tc(s, esp_get_stc(s));
928             }
929         } else {
930             s->dma = 0;
931         }
932         switch (val & CMD_CMD) {
933         case CMD_NOP:
934             trace_esp_mem_writeb_cmd_nop(val);
935             break;
936         case CMD_FLUSH:
937             trace_esp_mem_writeb_cmd_flush(val);
938             fifo8_reset(&s->fifo);
939             break;
940         case CMD_RESET:
941             trace_esp_mem_writeb_cmd_reset(val);
942             esp_soft_reset(s);
943             break;
944         case CMD_BUSRESET:
945             trace_esp_mem_writeb_cmd_bus_reset(val);
946             if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {
947                 s->rregs[ESP_RINTR] |= INTR_RST;
948                 esp_raise_irq(s);
949             }
950             break;
951         case CMD_TI:
952             trace_esp_mem_writeb_cmd_ti(val);
953             handle_ti(s);
954             break;
955         case CMD_ICCS:
956             trace_esp_mem_writeb_cmd_iccs(val);
957             write_response(s);
958             s->rregs[ESP_RINTR] |= INTR_FC;
959             s->rregs[ESP_RSTAT] |= STAT_MI;
960             break;
961         case CMD_MSGACC:
962             trace_esp_mem_writeb_cmd_msgacc(val);
963             s->rregs[ESP_RINTR] |= INTR_DC;
964             s->rregs[ESP_RSEQ] = 0;
965             s->rregs[ESP_RFLAGS] = 0;
966             esp_raise_irq(s);
967             break;
968         case CMD_PAD:
969             trace_esp_mem_writeb_cmd_pad(val);
970             s->rregs[ESP_RSTAT] = STAT_TC;
971             s->rregs[ESP_RINTR] |= INTR_FC;
972             s->rregs[ESP_RSEQ] = 0;
973             break;
974         case CMD_SATN:
975             trace_esp_mem_writeb_cmd_satn(val);
976             break;
977         case CMD_RSTATN:
978             trace_esp_mem_writeb_cmd_rstatn(val);
979             break;
980         case CMD_SEL:
981             trace_esp_mem_writeb_cmd_sel(val);
982             handle_s_without_atn(s);
983             break;
984         case CMD_SELATN:
985             trace_esp_mem_writeb_cmd_selatn(val);
986             handle_satn(s);
987             break;
988         case CMD_SELATNS:
989             trace_esp_mem_writeb_cmd_selatns(val);
990             handle_satn_stop(s);
991             break;
992         case CMD_ENSEL:
993             trace_esp_mem_writeb_cmd_ensel(val);
994             s->rregs[ESP_RINTR] = 0;
995             break;
996         case CMD_DISSEL:
997             trace_esp_mem_writeb_cmd_dissel(val);
998             s->rregs[ESP_RINTR] = 0;
999             esp_raise_irq(s);
1000             break;
1001         default:
1002             trace_esp_error_unhandled_command(val);
1003             break;
1004         }
1005         break;
1006     case ESP_WBUSID ... ESP_WSYNO:
1007         break;
1008     case ESP_CFG1:
1009     case ESP_CFG2: case ESP_CFG3:
1010     case ESP_RES3: case ESP_RES4:
1011         s->rregs[saddr] = val;
1012         break;
1013     case ESP_WCCF ... ESP_WTEST:
1014         break;
1015     default:
1016         trace_esp_error_invalid_write(val, saddr);
1017         return;
1018     }
1019     s->wregs[saddr] = val;
1020 }
1021 
1022 static bool esp_mem_accepts(void *opaque, hwaddr addr,
1023                             unsigned size, bool is_write,
1024                             MemTxAttrs attrs)
1025 {
1026     return (size == 1) || (is_write && size == 4);
1027 }
1028 
1029 static bool esp_is_before_version_5(void *opaque, int version_id)
1030 {
1031     ESPState *s = ESP(opaque);
1032 
1033     version_id = MIN(version_id, s->mig_version_id);
1034     return version_id < 5;
1035 }
1036 
1037 static bool esp_is_version_5(void *opaque, int version_id)
1038 {
1039     ESPState *s = ESP(opaque);
1040 
1041     version_id = MIN(version_id, s->mig_version_id);
1042     return version_id == 5;
1043 }
1044 
1045 static int esp_pre_save(void *opaque)
1046 {
1047     ESPState *s = ESP(opaque);
1048 
1049     s->mig_version_id = vmstate_esp.version_id;
1050     return 0;
1051 }
1052 
1053 static int esp_post_load(void *opaque, int version_id)
1054 {
1055     ESPState *s = ESP(opaque);
1056     int len, i;
1057 
1058     version_id = MIN(version_id, s->mig_version_id);
1059 
1060     if (version_id < 5) {
1061         esp_set_tc(s, s->mig_dma_left);
1062 
1063         /* Migrate ti_buf to fifo */
1064         len = s->mig_ti_wptr - s->mig_ti_rptr;
1065         for (i = 0; i < len; i++) {
1066             fifo8_push(&s->fifo, s->mig_ti_buf[i]);
1067         }
1068 
1069         /* Migrate cmdbuf to cmdfifo */
1070         for (i = 0; i < s->mig_cmdlen; i++) {
1071             fifo8_push(&s->cmdfifo, s->mig_cmdbuf[i]);
1072         }
1073     }
1074 
1075     s->mig_version_id = vmstate_esp.version_id;
1076     return 0;
1077 }
1078 
1079 const VMStateDescription vmstate_esp = {
1080     .name = "esp",
1081     .version_id = 5,
1082     .minimum_version_id = 3,
1083     .pre_save = esp_pre_save,
1084     .post_load = esp_post_load,
1085     .fields = (VMStateField[]) {
1086         VMSTATE_BUFFER(rregs, ESPState),
1087         VMSTATE_BUFFER(wregs, ESPState),
1088         VMSTATE_INT32(ti_size, ESPState),
1089         VMSTATE_UINT32_TEST(mig_ti_rptr, ESPState, esp_is_before_version_5),
1090         VMSTATE_UINT32_TEST(mig_ti_wptr, ESPState, esp_is_before_version_5),
1091         VMSTATE_BUFFER_TEST(mig_ti_buf, ESPState, esp_is_before_version_5),
1092         VMSTATE_UINT32(status, ESPState),
1093         VMSTATE_UINT32_TEST(mig_deferred_status, ESPState,
1094                             esp_is_before_version_5),
1095         VMSTATE_BOOL_TEST(mig_deferred_complete, ESPState,
1096                           esp_is_before_version_5),
1097         VMSTATE_UINT32(dma, ESPState),
1098         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 0,
1099                               esp_is_before_version_5, 0, 16),
1100         VMSTATE_STATIC_BUFFER(mig_cmdbuf, ESPState, 4,
1101                               esp_is_before_version_5, 16,
1102                               sizeof(typeof_field(ESPState, mig_cmdbuf))),
1103         VMSTATE_UINT32_TEST(mig_cmdlen, ESPState, esp_is_before_version_5),
1104         VMSTATE_UINT32(do_cmd, ESPState),
1105         VMSTATE_UINT32_TEST(mig_dma_left, ESPState, esp_is_before_version_5),
1106         VMSTATE_BOOL_TEST(data_in_ready, ESPState, esp_is_version_5),
1107         VMSTATE_UINT8_TEST(cmdfifo_cdb_offset, ESPState, esp_is_version_5),
1108         VMSTATE_FIFO8_TEST(fifo, ESPState, esp_is_version_5),
1109         VMSTATE_FIFO8_TEST(cmdfifo, ESPState, esp_is_version_5),
1110         VMSTATE_UINT8_TEST(ti_cmd, ESPState, esp_is_version_5),
1111         VMSTATE_END_OF_LIST()
1112     },
1113 };
1114 
1115 static void sysbus_esp_mem_write(void *opaque, hwaddr addr,
1116                                  uint64_t val, unsigned int size)
1117 {
1118     SysBusESPState *sysbus = opaque;
1119     ESPState *s = ESP(&sysbus->esp);
1120     uint32_t saddr;
1121 
1122     saddr = addr >> sysbus->it_shift;
1123     esp_reg_write(s, saddr, val);
1124 }
1125 
1126 static uint64_t sysbus_esp_mem_read(void *opaque, hwaddr addr,
1127                                     unsigned int size)
1128 {
1129     SysBusESPState *sysbus = opaque;
1130     ESPState *s = ESP(&sysbus->esp);
1131     uint32_t saddr;
1132 
1133     saddr = addr >> sysbus->it_shift;
1134     return esp_reg_read(s, saddr);
1135 }
1136 
1137 static const MemoryRegionOps sysbus_esp_mem_ops = {
1138     .read = sysbus_esp_mem_read,
1139     .write = sysbus_esp_mem_write,
1140     .endianness = DEVICE_NATIVE_ENDIAN,
1141     .valid.accepts = esp_mem_accepts,
1142 };
1143 
1144 static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
1145                                   uint64_t val, unsigned int size)
1146 {
1147     SysBusESPState *sysbus = opaque;
1148     ESPState *s = ESP(&sysbus->esp);
1149     uint32_t dmalen;
1150 
1151     trace_esp_pdma_write(size);
1152 
1153     switch (size) {
1154     case 1:
1155         esp_pdma_write(s, val);
1156         break;
1157     case 2:
1158         esp_pdma_write(s, val >> 8);
1159         esp_pdma_write(s, val);
1160         break;
1161     }
1162     dmalen = esp_get_tc(s);
1163     if (dmalen == 0 || fifo8_is_full(&s->fifo)) {
1164         s->pdma_cb(s);
1165     }
1166 }
1167 
1168 static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
1169                                      unsigned int size)
1170 {
1171     SysBusESPState *sysbus = opaque;
1172     ESPState *s = ESP(&sysbus->esp);
1173     uint64_t val = 0;
1174 
1175     trace_esp_pdma_read(size);
1176 
1177     switch (size) {
1178     case 1:
1179         val = esp_pdma_read(s);
1180         break;
1181     case 2:
1182         val = esp_pdma_read(s);
1183         val = (val << 8) | esp_pdma_read(s);
1184         break;
1185     }
1186     if (fifo8_is_empty(&s->fifo)) {
1187         s->pdma_cb(s);
1188     }
1189     return val;
1190 }
1191 
1192 static const MemoryRegionOps sysbus_esp_pdma_ops = {
1193     .read = sysbus_esp_pdma_read,
1194     .write = sysbus_esp_pdma_write,
1195     .endianness = DEVICE_NATIVE_ENDIAN,
1196     .valid.min_access_size = 1,
1197     .valid.max_access_size = 4,
1198     .impl.min_access_size = 1,
1199     .impl.max_access_size = 2,
1200 };
1201 
1202 static const struct SCSIBusInfo esp_scsi_info = {
1203     .tcq = false,
1204     .max_target = ESP_MAX_DEVS,
1205     .max_lun = 7,
1206 
1207     .transfer_data = esp_transfer_data,
1208     .complete = esp_command_complete,
1209     .cancel = esp_request_cancelled
1210 };
1211 
1212 static void sysbus_esp_gpio_demux(void *opaque, int irq, int level)
1213 {
1214     SysBusESPState *sysbus = SYSBUS_ESP(opaque);
1215     ESPState *s = ESP(&sysbus->esp);
1216 
1217     switch (irq) {
1218     case 0:
1219         parent_esp_reset(s, irq, level);
1220         break;
1221     case 1:
1222         esp_dma_enable(opaque, irq, level);
1223         break;
1224     }
1225 }
1226 
1227 static void sysbus_esp_realize(DeviceState *dev, Error **errp)
1228 {
1229     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
1230     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1231     ESPState *s = ESP(&sysbus->esp);
1232 
1233     if (!qdev_realize(DEVICE(s), NULL, errp)) {
1234         return;
1235     }
1236 
1237     sysbus_init_irq(sbd, &s->irq);
1238     sysbus_init_irq(sbd, &s->irq_data);
1239     assert(sysbus->it_shift != -1);
1240 
1241     s->chip_id = TCHI_FAS100A;
1242     memory_region_init_io(&sysbus->iomem, OBJECT(sysbus), &sysbus_esp_mem_ops,
1243                           sysbus, "esp-regs", ESP_REGS << sysbus->it_shift);
1244     sysbus_init_mmio(sbd, &sysbus->iomem);
1245     memory_region_init_io(&sysbus->pdma, OBJECT(sysbus), &sysbus_esp_pdma_ops,
1246                           sysbus, "esp-pdma", 4);
1247     sysbus_init_mmio(sbd, &sysbus->pdma);
1248 
1249     qdev_init_gpio_in(dev, sysbus_esp_gpio_demux, 2);
1250 
1251     scsi_bus_new(&s->bus, sizeof(s->bus), dev, &esp_scsi_info, NULL);
1252 }
1253 
1254 static void sysbus_esp_hard_reset(DeviceState *dev)
1255 {
1256     SysBusESPState *sysbus = SYSBUS_ESP(dev);
1257     ESPState *s = ESP(&sysbus->esp);
1258 
1259     esp_hard_reset(s);
1260 }
1261 
1262 static void sysbus_esp_init(Object *obj)
1263 {
1264     SysBusESPState *sysbus = SYSBUS_ESP(obj);
1265 
1266     object_initialize_child(obj, "esp", &sysbus->esp, TYPE_ESP);
1267 }
1268 
1269 static const VMStateDescription vmstate_sysbus_esp_scsi = {
1270     .name = "sysbusespscsi",
1271     .version_id = 2,
1272     .minimum_version_id = 1,
1273     .fields = (VMStateField[]) {
1274         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
1275         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
1276         VMSTATE_END_OF_LIST()
1277     }
1278 };
1279 
1280 static void sysbus_esp_class_init(ObjectClass *klass, void *data)
1281 {
1282     DeviceClass *dc = DEVICE_CLASS(klass);
1283 
1284     dc->realize = sysbus_esp_realize;
1285     dc->reset = sysbus_esp_hard_reset;
1286     dc->vmsd = &vmstate_sysbus_esp_scsi;
1287     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1288 }
1289 
1290 static const TypeInfo sysbus_esp_info = {
1291     .name          = TYPE_SYSBUS_ESP,
1292     .parent        = TYPE_SYS_BUS_DEVICE,
1293     .instance_init = sysbus_esp_init,
1294     .instance_size = sizeof(SysBusESPState),
1295     .class_init    = sysbus_esp_class_init,
1296 };
1297 
1298 static void esp_finalize(Object *obj)
1299 {
1300     ESPState *s = ESP(obj);
1301 
1302     fifo8_destroy(&s->fifo);
1303     fifo8_destroy(&s->cmdfifo);
1304 }
1305 
1306 static void esp_init(Object *obj)
1307 {
1308     ESPState *s = ESP(obj);
1309 
1310     fifo8_create(&s->fifo, ESP_FIFO_SZ);
1311     fifo8_create(&s->cmdfifo, ESP_CMDFIFO_SZ);
1312 }
1313 
1314 static void esp_class_init(ObjectClass *klass, void *data)
1315 {
1316     DeviceClass *dc = DEVICE_CLASS(klass);
1317 
1318     /* internal device for sysbusesp/pciespscsi, not user-creatable */
1319     dc->user_creatable = false;
1320     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1321 }
1322 
1323 static const TypeInfo esp_info = {
1324     .name = TYPE_ESP,
1325     .parent = TYPE_DEVICE,
1326     .instance_init = esp_init,
1327     .instance_finalize = esp_finalize,
1328     .instance_size = sizeof(ESPState),
1329     .class_init = esp_class_init,
1330 };
1331 
1332 static void esp_register_types(void)
1333 {
1334     type_register_static(&sysbus_esp_info);
1335     type_register_static(&esp_info);
1336 }
1337 
1338 type_init(esp_register_types)
1339