xref: /openbmc/qemu/hw/dma/i8257.c (revision 979a8902)
1 /*
2  * QEMU DMA emulation
3  *
4  * Copyright (c) 2003-2004 Vassili Karpov (malc)
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "hw/isa/isa.h"
27 #include "hw/qdev-properties.h"
28 #include "migration/vmstate.h"
29 #include "hw/dma/i8257.h"
30 #include "qemu/main-loop.h"
31 #include "qemu/module.h"
32 #include "qemu/log.h"
33 #include "trace.h"
34 
35 #define I8257(obj) \
36     OBJECT_CHECK(I8257State, (obj), TYPE_I8257)
37 
38 /* #define DEBUG_DMA */
39 
40 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
41 #ifdef DEBUG_DMA
42 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
43 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
44 #else
45 #define linfo(...)
46 #define ldebug(...)
47 #endif
48 
49 #define ADDR 0
50 #define COUNT 1
51 
52 enum {
53     CMD_MEMORY_TO_MEMORY = 0x01,
54     CMD_FIXED_ADDRESS    = 0x02,
55     CMD_BLOCK_CONTROLLER = 0x04,
56     CMD_COMPRESSED_TIME  = 0x08,
57     CMD_CYCLIC_PRIORITY  = 0x10,
58     CMD_EXTENDED_WRITE   = 0x20,
59     CMD_LOW_DREQ         = 0x40,
60     CMD_LOW_DACK         = 0x80,
61     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
62     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
63     | CMD_LOW_DREQ | CMD_LOW_DACK
64 
65 };
66 
67 static void i8257_dma_run(void *opaque);
68 
69 static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
70 
71 static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
72 {
73     I8257State *d = opaque;
74     int ichan;
75 
76     ichan = channels[nport & 7];
77     if (-1 == ichan) {
78         dolog ("invalid channel %#x %#x\n", nport, data);
79         return;
80     }
81     d->regs[ichan].page = data;
82 }
83 
84 static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
85 {
86     I8257State *d = opaque;
87     int ichan;
88 
89     ichan = channels[nport & 7];
90     if (-1 == ichan) {
91         dolog ("invalid channel %#x %#x\n", nport, data);
92         return;
93     }
94     d->regs[ichan].pageh = data;
95 }
96 
97 static uint32_t i8257_read_page(void *opaque, uint32_t nport)
98 {
99     I8257State *d = opaque;
100     int ichan;
101 
102     ichan = channels[nport & 7];
103     if (-1 == ichan) {
104         dolog ("invalid channel read %#x\n", nport);
105         return 0;
106     }
107     return d->regs[ichan].page;
108 }
109 
110 static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
111 {
112     I8257State *d = opaque;
113     int ichan;
114 
115     ichan = channels[nport & 7];
116     if (-1 == ichan) {
117         dolog ("invalid channel read %#x\n", nport);
118         return 0;
119     }
120     return d->regs[ichan].pageh;
121 }
122 
123 static inline void i8257_init_chan(I8257State *d, int ichan)
124 {
125     I8257Regs *r;
126 
127     r = d->regs + ichan;
128     r->now[ADDR] = r->base[ADDR] << d->dshift;
129     r->now[COUNT] = 0;
130 }
131 
132 static inline int i8257_getff(I8257State *d)
133 {
134     int ff;
135 
136     ff = d->flip_flop;
137     d->flip_flop = !ff;
138     return ff;
139 }
140 
141 static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
142 {
143     I8257State *d = opaque;
144     int ichan, nreg, iport, ff, val, dir;
145     I8257Regs *r;
146 
147     iport = (nport >> d->dshift) & 0x0f;
148     ichan = iport >> 1;
149     nreg = iport & 1;
150     r = d->regs + ichan;
151 
152     dir = ((r->mode >> 5) & 1) ? -1 : 1;
153     ff = i8257_getff(d);
154     if (nreg)
155         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
156     else
157         val = r->now[ADDR] + r->now[COUNT] * dir;
158 
159     ldebug ("read_chan %#x -> %d\n", iport, val);
160     return (val >> (d->dshift + (ff << 3))) & 0xff;
161 }
162 
163 static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
164                              unsigned int size)
165 {
166     I8257State *d = opaque;
167     int iport, ichan, nreg;
168     I8257Regs *r;
169 
170     iport = (nport >> d->dshift) & 0x0f;
171     ichan = iport >> 1;
172     nreg = iport & 1;
173     r = d->regs + ichan;
174     if (i8257_getff(d)) {
175         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
176         i8257_init_chan(d, ichan);
177     } else {
178         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
179     }
180 }
181 
182 static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
183                              unsigned int size)
184 {
185     I8257State *d = opaque;
186     int iport, ichan = 0;
187 
188     iport = (nport >> d->dshift) & 0x0f;
189     switch (iport) {
190     case 0x00:                  /* command */
191         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
192             qemu_log_mask(LOG_UNIMP, "%s: cmd 0x%02"PRIx64" not supported\n",
193                           __func__, data);
194             return;
195         }
196         d->command = data;
197         break;
198 
199     case 0x01:
200         ichan = data & 3;
201         if (data & 4) {
202             d->status |= 1 << (ichan + 4);
203         }
204         else {
205             d->status &= ~(1 << (ichan + 4));
206         }
207         d->status &= ~(1 << ichan);
208         i8257_dma_run(d);
209         break;
210 
211     case 0x02:                  /* single mask */
212         if (data & 4)
213             d->mask |= 1 << (data & 3);
214         else
215             d->mask &= ~(1 << (data & 3));
216         i8257_dma_run(d);
217         break;
218 
219     case 0x03:                  /* mode */
220         {
221             ichan = data & 3;
222 #ifdef DEBUG_DMA
223             {
224                 int op, ai, dir, opmode;
225                 op = (data >> 2) & 3;
226                 ai = (data >> 4) & 1;
227                 dir = (data >> 5) & 1;
228                 opmode = (data >> 6) & 3;
229 
230                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
231                        ichan, op, ai, dir, opmode);
232             }
233 #endif
234             d->regs[ichan].mode = data;
235             break;
236         }
237 
238     case 0x04:                  /* clear flip flop */
239         d->flip_flop = 0;
240         break;
241 
242     case 0x05:                  /* reset */
243         d->flip_flop = 0;
244         d->mask = ~0;
245         d->status = 0;
246         d->command = 0;
247         break;
248 
249     case 0x06:                  /* clear mask for all channels */
250         d->mask = 0;
251         i8257_dma_run(d);
252         break;
253 
254     case 0x07:                  /* write mask for all channels */
255         d->mask = data;
256         i8257_dma_run(d);
257         break;
258 
259     default:
260         dolog ("unknown iport %#x\n", iport);
261         break;
262     }
263 
264 #ifdef DEBUG_DMA
265     if (0xc != iport) {
266         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
267                nport, ichan, data);
268     }
269 #endif
270 }
271 
272 static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
273 {
274     I8257State *d = opaque;
275     int iport, val;
276 
277     iport = (nport >> d->dshift) & 0x0f;
278     switch (iport) {
279     case 0x00:                  /* status */
280         val = d->status;
281         d->status &= 0xf0;
282         break;
283     case 0x01:                  /* mask */
284         val = d->mask;
285         break;
286     default:
287         val = 0;
288         break;
289     }
290 
291     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
292     return val;
293 }
294 
295 static IsaDmaTransferMode i8257_dma_get_transfer_mode(IsaDma *obj, int nchan)
296 {
297     I8257State *d = I8257(obj);
298     return (d->regs[nchan & 3].mode >> 2) & 3;
299 }
300 
301 static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
302 {
303     I8257State *d = I8257(obj);
304     return (d->regs[nchan & 3].mode >> 4) & 1;
305 }
306 
307 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
308 {
309     I8257State *d = I8257(obj);
310     int ichan;
311 
312     ichan = nchan & 3;
313     d->status |= 1 << (ichan + 4);
314     i8257_dma_run(d);
315 }
316 
317 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
318 {
319     I8257State *d = I8257(obj);
320     int ichan;
321 
322     ichan = nchan & 3;
323     d->status &= ~(1 << (ichan + 4));
324     i8257_dma_run(d);
325 }
326 
327 static void i8257_channel_run(I8257State *d, int ichan)
328 {
329     int ncont = d->dshift;
330     int n;
331     I8257Regs *r = &d->regs[ichan];
332 #ifdef DEBUG_DMA
333     int dir, opmode;
334 
335     dir = (r->mode >> 5) & 1;
336     opmode = (r->mode >> 6) & 3;
337 
338     if (dir) {
339         dolog ("DMA in address decrement mode\n");
340     }
341     if (opmode != 1) {
342         dolog ("DMA not in single mode select %#x\n", opmode);
343     }
344 #endif
345 
346     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
347                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
348     r->now[COUNT] = n;
349     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
350     if (n == (r->base[COUNT] + 1) << ncont) {
351         ldebug("transfer done\n");
352         d->status |= (1 << ichan);
353     }
354 }
355 
356 static void i8257_dma_run(void *opaque)
357 {
358     I8257State *d = opaque;
359     int ichan;
360     int rearm = 0;
361 
362     if (d->running) {
363         rearm = 1;
364         goto out;
365     } else {
366         d->running = 1;
367     }
368 
369     for (ichan = 0; ichan < 4; ichan++) {
370         int mask;
371 
372         mask = 1 << ichan;
373 
374         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
375             i8257_channel_run(d, ichan);
376             rearm = 1;
377         }
378     }
379 
380     d->running = 0;
381 out:
382     if (rearm) {
383         qemu_bh_schedule_idle(d->dma_bh);
384         d->dma_bh_scheduled = true;
385     }
386 }
387 
388 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
389                                        IsaDmaTransferHandler transfer_handler,
390                                        void *opaque)
391 {
392     I8257State *d = I8257(obj);
393     I8257Regs *r;
394     int ichan;
395 
396     ichan = nchan & 3;
397 
398     r = d->regs + ichan;
399     r->transfer_handler = transfer_handler;
400     r->opaque = opaque;
401 }
402 
403 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
404                                  int len)
405 {
406     I8257State *d = I8257(obj);
407     I8257Regs *r = &d->regs[nchan & 3];
408     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
409 
410     if (r->mode & 0x20) {
411         int i;
412         uint8_t *p = buf;
413 
414         cpu_physical_memory_read (addr - pos - len, buf, len);
415         /* What about 16bit transfers? */
416         for (i = 0; i < len >> 1; i++) {
417             uint8_t b = p[len - i - 1];
418             p[i] = b;
419         }
420     }
421     else
422         cpu_physical_memory_read (addr + pos, buf, len);
423 
424     return len;
425 }
426 
427 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
428                                  int len)
429 {
430     I8257State *s = I8257(obj);
431     I8257Regs *r = &s->regs[nchan & 3];
432     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
433 
434     if (r->mode & 0x20) {
435         int i;
436         uint8_t *p = buf;
437 
438         cpu_physical_memory_write (addr - pos - len, buf, len);
439         /* What about 16bit transfers? */
440         for (i = 0; i < len; i++) {
441             uint8_t b = p[len - i - 1];
442             p[i] = b;
443         }
444     }
445     else
446         cpu_physical_memory_write (addr + pos, buf, len);
447 
448     return len;
449 }
450 
451 /* request the emulator to transfer a new DMA memory block ASAP (even
452  * if the idle bottom half would not have exited the iothread yet).
453  */
454 static void i8257_dma_schedule(IsaDma *obj)
455 {
456     I8257State *d = I8257(obj);
457     if (d->dma_bh_scheduled) {
458         qemu_notify_event();
459     }
460 }
461 
462 static void i8257_reset(DeviceState *dev)
463 {
464     I8257State *d = I8257(dev);
465     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
466 }
467 
468 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
469                                int dma_len)
470 {
471     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
472     return dma_pos;
473 }
474 
475 
476 static const MemoryRegionOps channel_io_ops = {
477     .read = i8257_read_chan,
478     .write = i8257_write_chan,
479     .endianness = DEVICE_NATIVE_ENDIAN,
480     .impl = {
481         .min_access_size = 1,
482         .max_access_size = 1,
483     },
484 };
485 
486 /* IOport from page_base */
487 static const MemoryRegionPortio page_portio_list[] = {
488     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
489     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
490     PORTIO_END_OF_LIST(),
491 };
492 
493 /* IOport from pageh_base */
494 static const MemoryRegionPortio pageh_portio_list[] = {
495     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
496     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
497     PORTIO_END_OF_LIST(),
498 };
499 
500 static const MemoryRegionOps cont_io_ops = {
501     .read = i8257_read_cont,
502     .write = i8257_write_cont,
503     .endianness = DEVICE_NATIVE_ENDIAN,
504     .impl = {
505         .min_access_size = 1,
506         .max_access_size = 1,
507     },
508 };
509 
510 static const VMStateDescription vmstate_i8257_regs = {
511     .name = "dma_regs",
512     .version_id = 1,
513     .minimum_version_id = 1,
514     .fields = (VMStateField[]) {
515         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
516         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
517         VMSTATE_UINT8(mode, I8257Regs),
518         VMSTATE_UINT8(page, I8257Regs),
519         VMSTATE_UINT8(pageh, I8257Regs),
520         VMSTATE_UINT8(dack, I8257Regs),
521         VMSTATE_UINT8(eop, I8257Regs),
522         VMSTATE_END_OF_LIST()
523     }
524 };
525 
526 static int i8257_post_load(void *opaque, int version_id)
527 {
528     I8257State *d = opaque;
529     i8257_dma_run(d);
530 
531     return 0;
532 }
533 
534 static const VMStateDescription vmstate_i8257 = {
535     .name = "dma",
536     .version_id = 1,
537     .minimum_version_id = 1,
538     .post_load = i8257_post_load,
539     .fields = (VMStateField[]) {
540         VMSTATE_UINT8(command, I8257State),
541         VMSTATE_UINT8(mask, I8257State),
542         VMSTATE_UINT8(flip_flop, I8257State),
543         VMSTATE_INT32(dshift, I8257State),
544         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
545                              I8257Regs),
546         VMSTATE_END_OF_LIST()
547     }
548 };
549 
550 static void i8257_realize(DeviceState *dev, Error **errp)
551 {
552     ISADevice *isa = ISA_DEVICE(dev);
553     I8257State *d = I8257(dev);
554     int i;
555 
556     memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d,
557                           "dma-chan", 8 << d->dshift);
558     memory_region_add_subregion(isa_address_space_io(isa),
559                                 d->base, &d->channel_io);
560 
561     isa_register_portio_list(isa, &d->portio_page,
562                              d->page_base, page_portio_list, d,
563                              "dma-page");
564     if (d->pageh_base >= 0) {
565         isa_register_portio_list(isa, &d->portio_pageh,
566                                  d->pageh_base, pageh_portio_list, d,
567                                  "dma-pageh");
568     }
569 
570     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
571                           "dma-cont", 8 << d->dshift);
572     memory_region_add_subregion(isa_address_space_io(isa),
573                                 d->base + (8 << d->dshift), &d->cont_io);
574 
575     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
576         d->regs[i].transfer_handler = i8257_phony_handler;
577     }
578 
579     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
580 }
581 
582 static Property i8257_properties[] = {
583     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
584     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
585     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
586     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
587     DEFINE_PROP_END_OF_LIST()
588 };
589 
590 static void i8257_class_init(ObjectClass *klass, void *data)
591 {
592     DeviceClass *dc = DEVICE_CLASS(klass);
593     IsaDmaClass *idc = ISADMA_CLASS(klass);
594 
595     dc->realize = i8257_realize;
596     dc->reset = i8257_reset;
597     dc->vmsd = &vmstate_i8257;
598     device_class_set_props(dc, i8257_properties);
599 
600     idc->get_transfer_mode = i8257_dma_get_transfer_mode;
601     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
602     idc->read_memory = i8257_dma_read_memory;
603     idc->write_memory = i8257_dma_write_memory;
604     idc->hold_DREQ = i8257_dma_hold_DREQ;
605     idc->release_DREQ = i8257_dma_release_DREQ;
606     idc->schedule = i8257_dma_schedule;
607     idc->register_channel = i8257_dma_register_channel;
608     /* Reason: needs to be wired up by isa_bus_dma() to work */
609     dc->user_creatable = false;
610 }
611 
612 static const TypeInfo i8257_info = {
613     .name = TYPE_I8257,
614     .parent = TYPE_ISA_DEVICE,
615     .instance_size = sizeof(I8257State),
616     .class_init = i8257_class_init,
617     .interfaces = (InterfaceInfo[]) {
618         { TYPE_ISADMA },
619         { }
620     }
621 };
622 
623 static void i8257_register_types(void)
624 {
625     type_register_static(&i8257_info);
626 }
627 
628 type_init(i8257_register_types)
629 
630 void i8257_dma_init(ISABus *bus, bool high_page_enable)
631 {
632     ISADevice *isa1, *isa2;
633     DeviceState *d;
634 
635     isa1 = isa_create(bus, TYPE_I8257);
636     d = DEVICE(isa1);
637     qdev_prop_set_int32(d, "base", 0x00);
638     qdev_prop_set_int32(d, "page-base", 0x80);
639     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
640     qdev_prop_set_int32(d, "dshift", 0);
641     qdev_init_nofail(d);
642 
643     isa2 = isa_create(bus, TYPE_I8257);
644     d = DEVICE(isa2);
645     qdev_prop_set_int32(d, "base", 0xc0);
646     qdev_prop_set_int32(d, "page-base", 0x88);
647     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
648     qdev_prop_set_int32(d, "dshift", 1);
649     qdev_init_nofail(d);
650 
651     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
652 }
653