xref: /openbmc/qemu/hw/dma/i8257.c (revision 40bd0502)
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 bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
296 {
297     I8257State *d = I8257(obj);
298     return (d->regs[nchan & 3].mode >> 4) & 1;
299 }
300 
301 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
302 {
303     I8257State *d = I8257(obj);
304     int ichan;
305 
306     ichan = nchan & 3;
307     d->status |= 1 << (ichan + 4);
308     i8257_dma_run(d);
309 }
310 
311 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
312 {
313     I8257State *d = I8257(obj);
314     int ichan;
315 
316     ichan = nchan & 3;
317     d->status &= ~(1 << (ichan + 4));
318     i8257_dma_run(d);
319 }
320 
321 static void i8257_channel_run(I8257State *d, int ichan)
322 {
323     int ncont = d->dshift;
324     int n;
325     I8257Regs *r = &d->regs[ichan];
326 #ifdef DEBUG_DMA
327     int dir, opmode;
328 
329     dir = (r->mode >> 5) & 1;
330     opmode = (r->mode >> 6) & 3;
331 
332     if (dir) {
333         dolog ("DMA in address decrement mode\n");
334     }
335     if (opmode != 1) {
336         dolog ("DMA not in single mode select %#x\n", opmode);
337     }
338 #endif
339 
340     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
341                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
342     r->now[COUNT] = n;
343     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
344     if (n == (r->base[COUNT] + 1) << ncont) {
345         ldebug("transfer done\n");
346         d->status |= (1 << ichan);
347     }
348 }
349 
350 static void i8257_dma_run(void *opaque)
351 {
352     I8257State *d = opaque;
353     int ichan;
354     int rearm = 0;
355 
356     if (d->running) {
357         rearm = 1;
358         goto out;
359     } else {
360         d->running = 1;
361     }
362 
363     for (ichan = 0; ichan < 4; ichan++) {
364         int mask;
365 
366         mask = 1 << ichan;
367 
368         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
369             i8257_channel_run(d, ichan);
370             rearm = 1;
371         }
372     }
373 
374     d->running = 0;
375 out:
376     if (rearm) {
377         qemu_bh_schedule_idle(d->dma_bh);
378         d->dma_bh_scheduled = true;
379     }
380 }
381 
382 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
383                                        IsaDmaTransferHandler transfer_handler,
384                                        void *opaque)
385 {
386     I8257State *d = I8257(obj);
387     I8257Regs *r;
388     int ichan;
389 
390     ichan = nchan & 3;
391 
392     r = d->regs + ichan;
393     r->transfer_handler = transfer_handler;
394     r->opaque = opaque;
395 }
396 
397 static bool i8257_is_verify_transfer(I8257Regs *r)
398 {
399     return (r->mode & 0x0c) == 0;
400 }
401 
402 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
403                                  int len)
404 {
405     I8257State *d = I8257(obj);
406     I8257Regs *r = &d->regs[nchan & 3];
407     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
408 
409     if (i8257_is_verify_transfer(r)) {
410         return len;
411     }
412 
413     if (r->mode & 0x20) {
414         int i;
415         uint8_t *p = buf;
416 
417         cpu_physical_memory_read (addr - pos - len, buf, len);
418         /* What about 16bit transfers? */
419         for (i = 0; i < len >> 1; i++) {
420             uint8_t b = p[len - i - 1];
421             p[i] = b;
422         }
423     }
424     else
425         cpu_physical_memory_read (addr + pos, buf, len);
426 
427     return len;
428 }
429 
430 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
431                                  int len)
432 {
433     I8257State *s = I8257(obj);
434     I8257Regs *r = &s->regs[nchan & 3];
435     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
436 
437     if (i8257_is_verify_transfer(r)) {
438         return len;
439     }
440 
441     if (r->mode & 0x20) {
442         int i;
443         uint8_t *p = buf;
444 
445         cpu_physical_memory_write (addr - pos - len, buf, len);
446         /* What about 16bit transfers? */
447         for (i = 0; i < len; i++) {
448             uint8_t b = p[len - i - 1];
449             p[i] = b;
450         }
451     }
452     else
453         cpu_physical_memory_write (addr + pos, buf, len);
454 
455     return len;
456 }
457 
458 /* request the emulator to transfer a new DMA memory block ASAP (even
459  * if the idle bottom half would not have exited the iothread yet).
460  */
461 static void i8257_dma_schedule(IsaDma *obj)
462 {
463     I8257State *d = I8257(obj);
464     if (d->dma_bh_scheduled) {
465         qemu_notify_event();
466     }
467 }
468 
469 static void i8257_reset(DeviceState *dev)
470 {
471     I8257State *d = I8257(dev);
472     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
473 }
474 
475 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
476                                int dma_len)
477 {
478     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
479     return dma_pos;
480 }
481 
482 
483 static const MemoryRegionOps channel_io_ops = {
484     .read = i8257_read_chan,
485     .write = i8257_write_chan,
486     .endianness = DEVICE_NATIVE_ENDIAN,
487     .impl = {
488         .min_access_size = 1,
489         .max_access_size = 1,
490     },
491 };
492 
493 /* IOport from page_base */
494 static const MemoryRegionPortio page_portio_list[] = {
495     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
496     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
497     PORTIO_END_OF_LIST(),
498 };
499 
500 /* IOport from pageh_base */
501 static const MemoryRegionPortio pageh_portio_list[] = {
502     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
503     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
504     PORTIO_END_OF_LIST(),
505 };
506 
507 static const MemoryRegionOps cont_io_ops = {
508     .read = i8257_read_cont,
509     .write = i8257_write_cont,
510     .endianness = DEVICE_NATIVE_ENDIAN,
511     .impl = {
512         .min_access_size = 1,
513         .max_access_size = 1,
514     },
515 };
516 
517 static const VMStateDescription vmstate_i8257_regs = {
518     .name = "dma_regs",
519     .version_id = 1,
520     .minimum_version_id = 1,
521     .fields = (VMStateField[]) {
522         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
523         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
524         VMSTATE_UINT8(mode, I8257Regs),
525         VMSTATE_UINT8(page, I8257Regs),
526         VMSTATE_UINT8(pageh, I8257Regs),
527         VMSTATE_UINT8(dack, I8257Regs),
528         VMSTATE_UINT8(eop, I8257Regs),
529         VMSTATE_END_OF_LIST()
530     }
531 };
532 
533 static int i8257_post_load(void *opaque, int version_id)
534 {
535     I8257State *d = opaque;
536     i8257_dma_run(d);
537 
538     return 0;
539 }
540 
541 static const VMStateDescription vmstate_i8257 = {
542     .name = "dma",
543     .version_id = 1,
544     .minimum_version_id = 1,
545     .post_load = i8257_post_load,
546     .fields = (VMStateField[]) {
547         VMSTATE_UINT8(command, I8257State),
548         VMSTATE_UINT8(mask, I8257State),
549         VMSTATE_UINT8(flip_flop, I8257State),
550         VMSTATE_INT32(dshift, I8257State),
551         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
552                              I8257Regs),
553         VMSTATE_END_OF_LIST()
554     }
555 };
556 
557 static void i8257_realize(DeviceState *dev, Error **errp)
558 {
559     ISADevice *isa = ISA_DEVICE(dev);
560     I8257State *d = I8257(dev);
561     int i;
562 
563     memory_region_init_io(&d->channel_io, OBJECT(dev), &channel_io_ops, d,
564                           "dma-chan", 8 << d->dshift);
565     memory_region_add_subregion(isa_address_space_io(isa),
566                                 d->base, &d->channel_io);
567 
568     isa_register_portio_list(isa, &d->portio_page,
569                              d->page_base, page_portio_list, d,
570                              "dma-page");
571     if (d->pageh_base >= 0) {
572         isa_register_portio_list(isa, &d->portio_pageh,
573                                  d->pageh_base, pageh_portio_list, d,
574                                  "dma-pageh");
575     }
576 
577     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
578                           "dma-cont", 8 << d->dshift);
579     memory_region_add_subregion(isa_address_space_io(isa),
580                                 d->base + (8 << d->dshift), &d->cont_io);
581 
582     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
583         d->regs[i].transfer_handler = i8257_phony_handler;
584     }
585 
586     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
587 }
588 
589 static Property i8257_properties[] = {
590     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
591     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
592     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
593     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
594     DEFINE_PROP_END_OF_LIST()
595 };
596 
597 static void i8257_class_init(ObjectClass *klass, void *data)
598 {
599     DeviceClass *dc = DEVICE_CLASS(klass);
600     IsaDmaClass *idc = ISADMA_CLASS(klass);
601 
602     dc->realize = i8257_realize;
603     dc->reset = i8257_reset;
604     dc->vmsd = &vmstate_i8257;
605     device_class_set_props(dc, i8257_properties);
606 
607     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
608     idc->read_memory = i8257_dma_read_memory;
609     idc->write_memory = i8257_dma_write_memory;
610     idc->hold_DREQ = i8257_dma_hold_DREQ;
611     idc->release_DREQ = i8257_dma_release_DREQ;
612     idc->schedule = i8257_dma_schedule;
613     idc->register_channel = i8257_dma_register_channel;
614     /* Reason: needs to be wired up by isa_bus_dma() to work */
615     dc->user_creatable = false;
616 }
617 
618 static const TypeInfo i8257_info = {
619     .name = TYPE_I8257,
620     .parent = TYPE_ISA_DEVICE,
621     .instance_size = sizeof(I8257State),
622     .class_init = i8257_class_init,
623     .interfaces = (InterfaceInfo[]) {
624         { TYPE_ISADMA },
625         { }
626     }
627 };
628 
629 static void i8257_register_types(void)
630 {
631     type_register_static(&i8257_info);
632 }
633 
634 type_init(i8257_register_types)
635 
636 void i8257_dma_init(ISABus *bus, bool high_page_enable)
637 {
638     ISADevice *isa1, *isa2;
639     DeviceState *d;
640 
641     isa1 = isa_create(bus, TYPE_I8257);
642     d = DEVICE(isa1);
643     qdev_prop_set_int32(d, "base", 0x00);
644     qdev_prop_set_int32(d, "page-base", 0x80);
645     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
646     qdev_prop_set_int32(d, "dshift", 0);
647     qdev_init_nofail(d);
648 
649     isa2 = isa_create(bus, TYPE_I8257);
650     d = DEVICE(isa2);
651     qdev_prop_set_int32(d, "base", 0xc0);
652     qdev_prop_set_int32(d, "page-base", 0x88);
653     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
654     qdev_prop_set_int32(d, "dshift", 1);
655     qdev_init_nofail(d);
656 
657     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
658 }
659