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 "qapi/error.h"
31 #include "qemu/main-loop.h"
32 #include "qemu/module.h"
33 #include "qemu/log.h"
34 #include "trace.h"
35
36
37 /* #define DEBUG_DMA */
38
39 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
40 #ifdef DEBUG_DMA
41 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
42 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
43 #else
44 #define linfo(...)
45 #define ldebug(...)
46 #endif
47
48 #define ADDR 0
49 #define COUNT 1
50
51 enum {
52 CMD_MEMORY_TO_MEMORY = 0x01,
53 CMD_FIXED_ADDRESS = 0x02,
54 CMD_BLOCK_CONTROLLER = 0x04,
55 CMD_COMPRESSED_TIME = 0x08,
56 CMD_CYCLIC_PRIORITY = 0x10,
57 CMD_EXTENDED_WRITE = 0x20,
58 CMD_LOW_DREQ = 0x40,
59 CMD_LOW_DACK = 0x80,
60 CMD_NOT_SUPPORTED = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
61 | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
62 | CMD_LOW_DREQ | CMD_LOW_DACK
63
64 };
65
66 static void i8257_dma_run(void *opaque);
67
68 static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
69
i8257_write_page(void * opaque,uint32_t nport,uint32_t data)70 static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
71 {
72 I8257State *d = opaque;
73 int ichan;
74
75 ichan = channels[nport & 7];
76 if (-1 == ichan) {
77 dolog ("invalid channel %#x %#x\n", nport, data);
78 return;
79 }
80 d->regs[ichan].page = data;
81 }
82
i8257_write_pageh(void * opaque,uint32_t nport,uint32_t data)83 static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
84 {
85 I8257State *d = opaque;
86 int ichan;
87
88 ichan = channels[nport & 7];
89 if (-1 == ichan) {
90 dolog ("invalid channel %#x %#x\n", nport, data);
91 return;
92 }
93 d->regs[ichan].pageh = data;
94 }
95
i8257_read_page(void * opaque,uint32_t nport)96 static uint32_t i8257_read_page(void *opaque, uint32_t nport)
97 {
98 I8257State *d = opaque;
99 int ichan;
100
101 ichan = channels[nport & 7];
102 if (-1 == ichan) {
103 dolog ("invalid channel read %#x\n", nport);
104 return 0;
105 }
106 return d->regs[ichan].page;
107 }
108
i8257_read_pageh(void * opaque,uint32_t nport)109 static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
110 {
111 I8257State *d = opaque;
112 int ichan;
113
114 ichan = channels[nport & 7];
115 if (-1 == ichan) {
116 dolog ("invalid channel read %#x\n", nport);
117 return 0;
118 }
119 return d->regs[ichan].pageh;
120 }
121
i8257_init_chan(I8257State * d,int ichan)122 static inline void i8257_init_chan(I8257State *d, int ichan)
123 {
124 I8257Regs *r;
125
126 r = d->regs + ichan;
127 r->now[ADDR] = r->base[ADDR] << d->dshift;
128 r->now[COUNT] = 0;
129 }
130
i8257_getff(I8257State * d)131 static inline int i8257_getff(I8257State *d)
132 {
133 int ff;
134
135 ff = d->flip_flop;
136 d->flip_flop = !ff;
137 return ff;
138 }
139
i8257_read_chan(void * opaque,hwaddr nport,unsigned size)140 static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
141 {
142 I8257State *d = opaque;
143 int ichan, nreg, iport, ff, val, dir;
144 I8257Regs *r;
145
146 iport = (nport >> d->dshift) & 0x0f;
147 ichan = iport >> 1;
148 nreg = iport & 1;
149 r = d->regs + ichan;
150
151 dir = ((r->mode >> 5) & 1) ? -1 : 1;
152 ff = i8257_getff(d);
153 if (nreg)
154 val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
155 else
156 val = r->now[ADDR] + r->now[COUNT] * dir;
157
158 ldebug ("read_chan %#x -> %d\n", iport, val);
159 return (val >> (d->dshift + (ff << 3))) & 0xff;
160 }
161
i8257_write_chan(void * opaque,hwaddr nport,uint64_t data,unsigned int size)162 static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
163 unsigned int size)
164 {
165 I8257State *d = opaque;
166 int iport, ichan, nreg;
167 I8257Regs *r;
168
169 iport = (nport >> d->dshift) & 0x0f;
170 ichan = iport >> 1;
171 nreg = iport & 1;
172 r = d->regs + ichan;
173 if (i8257_getff(d)) {
174 r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
175 i8257_init_chan(d, ichan);
176 } else {
177 r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
178 }
179 }
180
i8257_write_cont(void * opaque,hwaddr nport,uint64_t data,unsigned int size)181 static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
182 unsigned int size)
183 {
184 I8257State *d = opaque;
185 int iport, ichan = 0;
186
187 iport = (nport >> d->dshift) & 0x0f;
188 switch (iport) {
189 case 0x00: /* command */
190 if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
191 qemu_log_mask(LOG_UNIMP, "%s: cmd 0x%02"PRIx64" not supported\n",
192 __func__, data);
193 return;
194 }
195 d->command = data;
196 break;
197
198 case 0x01:
199 ichan = data & 3;
200 if (data & 4) {
201 d->status |= 1 << (ichan + 4);
202 }
203 else {
204 d->status &= ~(1 << (ichan + 4));
205 }
206 d->status &= ~(1 << ichan);
207 i8257_dma_run(d);
208 break;
209
210 case 0x02: /* single mask */
211 if (data & 4)
212 d->mask |= 1 << (data & 3);
213 else
214 d->mask &= ~(1 << (data & 3));
215 i8257_dma_run(d);
216 break;
217
218 case 0x03: /* mode */
219 {
220 ichan = data & 3;
221 #ifdef DEBUG_DMA
222 {
223 int op, ai, dir, opmode;
224 op = (data >> 2) & 3;
225 ai = (data >> 4) & 1;
226 dir = (data >> 5) & 1;
227 opmode = (data >> 6) & 3;
228
229 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
230 ichan, op, ai, dir, opmode);
231 }
232 #endif
233 d->regs[ichan].mode = data;
234 break;
235 }
236
237 case 0x04: /* clear flip flop */
238 d->flip_flop = 0;
239 break;
240
241 case 0x05: /* reset */
242 d->flip_flop = 0;
243 d->mask = ~0;
244 d->status = 0;
245 d->command = 0;
246 break;
247
248 case 0x06: /* clear mask for all channels */
249 d->mask = 0;
250 i8257_dma_run(d);
251 break;
252
253 case 0x07: /* write mask for all channels */
254 d->mask = data;
255 i8257_dma_run(d);
256 break;
257
258 default:
259 dolog ("unknown iport %#x\n", iport);
260 break;
261 }
262
263 #ifdef DEBUG_DMA
264 if (0xc != iport) {
265 linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
266 nport, ichan, data);
267 }
268 #endif
269 }
270
i8257_read_cont(void * opaque,hwaddr nport,unsigned size)271 static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
272 {
273 I8257State *d = opaque;
274 int iport, val;
275
276 iport = (nport >> d->dshift) & 0x0f;
277 switch (iport) {
278 case 0x00: /* status */
279 val = d->status;
280 d->status &= 0xf0;
281 break;
282 case 0x01: /* mask */
283 val = d->mask;
284 break;
285 default:
286 val = 0;
287 break;
288 }
289
290 ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
291 return val;
292 }
293
i8257_dma_has_autoinitialization(IsaDma * obj,int nchan)294 static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
295 {
296 I8257State *d = I8257(obj);
297 return (d->regs[nchan & 3].mode >> 4) & 1;
298 }
299
i8257_dma_hold_DREQ(IsaDma * obj,int nchan)300 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
301 {
302 I8257State *d = I8257(obj);
303 int ichan;
304
305 ichan = nchan & 3;
306 d->status |= 1 << (ichan + 4);
307 i8257_dma_run(d);
308 }
309
i8257_dma_release_DREQ(IsaDma * obj,int nchan)310 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
311 {
312 I8257State *d = I8257(obj);
313 int ichan;
314
315 ichan = nchan & 3;
316 d->status &= ~(1 << (ichan + 4));
317 i8257_dma_run(d);
318 }
319
i8257_channel_run(I8257State * d,int ichan)320 static void i8257_channel_run(I8257State *d, int ichan)
321 {
322 int ncont = d->dshift;
323 int n;
324 I8257Regs *r = &d->regs[ichan];
325 #ifdef DEBUG_DMA
326 int dir, opmode;
327
328 dir = (r->mode >> 5) & 1;
329 opmode = (r->mode >> 6) & 3;
330
331 if (dir) {
332 dolog ("DMA in address decrement mode\n");
333 }
334 if (opmode != 1) {
335 dolog ("DMA not in single mode select %#x\n", opmode);
336 }
337 #endif
338
339 n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
340 r->now[COUNT], (r->base[COUNT] + 1) << ncont);
341 r->now[COUNT] = n;
342 ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
343 if (n == (r->base[COUNT] + 1) << ncont) {
344 ldebug("transfer done\n");
345 d->status |= (1 << ichan);
346 }
347 }
348
i8257_dma_run(void * opaque)349 static void i8257_dma_run(void *opaque)
350 {
351 I8257State *d = opaque;
352 int ichan;
353 int rearm = 0;
354
355 if (d->running) {
356 rearm = 1;
357 goto out;
358 } else {
359 d->running = 1;
360 }
361
362 for (ichan = 0; ichan < 4; ichan++) {
363 int mask;
364
365 mask = 1 << ichan;
366
367 if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
368 i8257_channel_run(d, ichan);
369 rearm = 1;
370 }
371 }
372
373 d->running = 0;
374 out:
375 if (rearm) {
376 qemu_bh_schedule_idle(d->dma_bh);
377 d->dma_bh_scheduled = true;
378 }
379 }
380
i8257_dma_register_channel(IsaDma * obj,int nchan,IsaDmaTransferHandler transfer_handler,void * opaque)381 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
382 IsaDmaTransferHandler transfer_handler,
383 void *opaque)
384 {
385 I8257State *d = I8257(obj);
386 I8257Regs *r;
387 int ichan;
388
389 ichan = nchan & 3;
390
391 r = d->regs + ichan;
392 r->transfer_handler = transfer_handler;
393 r->opaque = opaque;
394 }
395
i8257_is_verify_transfer(I8257Regs * r)396 static bool i8257_is_verify_transfer(I8257Regs *r)
397 {
398 return (r->mode & 0x0c) == 0;
399 }
400
i8257_dma_read_memory(IsaDma * obj,int nchan,void * buf,int pos,int len)401 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
402 int len)
403 {
404 I8257State *d = I8257(obj);
405 I8257Regs *r = &d->regs[nchan & 3];
406 hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
407
408 if (i8257_is_verify_transfer(r)) {
409 return len;
410 }
411
412 if (r->mode & 0x20) {
413 int i;
414 uint8_t *p = buf;
415
416 cpu_physical_memory_read (addr - pos - len, buf, len);
417 /* What about 16bit transfers? */
418 for (i = 0; i < len >> 1; i++) {
419 uint8_t b = p[len - i - 1];
420 p[i] = b;
421 }
422 }
423 else
424 cpu_physical_memory_read (addr + pos, buf, len);
425
426 return len;
427 }
428
i8257_dma_write_memory(IsaDma * obj,int nchan,void * buf,int pos,int len)429 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
430 int len)
431 {
432 I8257State *s = I8257(obj);
433 I8257Regs *r = &s->regs[nchan & 3];
434 hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
435
436 if (i8257_is_verify_transfer(r)) {
437 return len;
438 }
439
440 if (r->mode & 0x20) {
441 int i;
442 uint8_t *p = buf;
443
444 cpu_physical_memory_write (addr - pos - len, buf, len);
445 /* What about 16bit transfers? */
446 for (i = 0; i < len; i++) {
447 uint8_t b = p[len - i - 1];
448 p[i] = b;
449 }
450 }
451 else
452 cpu_physical_memory_write (addr + pos, buf, len);
453
454 return len;
455 }
456
457 /* request the emulator to transfer a new DMA memory block ASAP (even
458 * if the idle bottom half would not have exited the iothread yet).
459 */
i8257_dma_schedule(IsaDma * obj)460 static void i8257_dma_schedule(IsaDma *obj)
461 {
462 I8257State *d = I8257(obj);
463 if (d->dma_bh_scheduled) {
464 qemu_notify_event();
465 }
466 }
467
i8257_reset(DeviceState * dev)468 static void i8257_reset(DeviceState *dev)
469 {
470 I8257State *d = I8257(dev);
471 i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
472 }
473
i8257_phony_handler(void * opaque,int nchan,int dma_pos,int dma_len)474 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
475 int dma_len)
476 {
477 trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
478 return dma_pos;
479 }
480
481
482 static const MemoryRegionOps channel_io_ops = {
483 .read = i8257_read_chan,
484 .write = i8257_write_chan,
485 .endianness = DEVICE_NATIVE_ENDIAN,
486 .impl = {
487 .min_access_size = 1,
488 .max_access_size = 1,
489 },
490 };
491
492 /* IOport from page_base */
493 static const MemoryRegionPortio page_portio_list[] = {
494 { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
495 { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
496 PORTIO_END_OF_LIST(),
497 };
498
499 /* IOport from pageh_base */
500 static const MemoryRegionPortio pageh_portio_list[] = {
501 { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
502 { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
503 PORTIO_END_OF_LIST(),
504 };
505
506 static const MemoryRegionOps cont_io_ops = {
507 .read = i8257_read_cont,
508 .write = i8257_write_cont,
509 .endianness = DEVICE_NATIVE_ENDIAN,
510 .impl = {
511 .min_access_size = 1,
512 .max_access_size = 1,
513 },
514 };
515
516 static const VMStateDescription vmstate_i8257_regs = {
517 .name = "dma_regs",
518 .version_id = 1,
519 .minimum_version_id = 1,
520 .fields = (const VMStateField[]) {
521 VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
522 VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
523 VMSTATE_UINT8(mode, I8257Regs),
524 VMSTATE_UINT8(page, I8257Regs),
525 VMSTATE_UINT8(pageh, I8257Regs),
526 VMSTATE_UINT8(dack, I8257Regs),
527 VMSTATE_UINT8(eop, I8257Regs),
528 VMSTATE_END_OF_LIST()
529 }
530 };
531
i8257_post_load(void * opaque,int version_id)532 static int i8257_post_load(void *opaque, int version_id)
533 {
534 I8257State *d = opaque;
535 i8257_dma_run(d);
536
537 return 0;
538 }
539
540 static const VMStateDescription vmstate_i8257 = {
541 .name = "dma",
542 .version_id = 1,
543 .minimum_version_id = 1,
544 .post_load = i8257_post_load,
545 .fields = (const VMStateField[]) {
546 VMSTATE_UINT8(command, I8257State),
547 VMSTATE_UINT8(mask, I8257State),
548 VMSTATE_UINT8(flip_flop, I8257State),
549 VMSTATE_INT32(dshift, I8257State),
550 VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
551 I8257Regs),
552 VMSTATE_END_OF_LIST()
553 }
554 };
555
i8257_realize(DeviceState * dev,Error ** errp)556 static void i8257_realize(DeviceState *dev, Error **errp)
557 {
558 ISADevice *isa = ISA_DEVICE(dev);
559 I8257State *d = I8257(dev);
560 int i;
561
562 memory_region_init_io(&d->channel_io, OBJECT(dev), &channel_io_ops, d,
563 "dma-chan", 8 << d->dshift);
564 memory_region_add_subregion(isa_address_space_io(isa),
565 d->base, &d->channel_io);
566
567 isa_register_portio_list(isa, &d->portio_page,
568 d->page_base, page_portio_list, d,
569 "dma-page");
570 if (d->pageh_base >= 0) {
571 isa_register_portio_list(isa, &d->portio_pageh,
572 d->pageh_base, pageh_portio_list, d,
573 "dma-pageh");
574 }
575
576 memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
577 "dma-cont", 8 << d->dshift);
578 memory_region_add_subregion(isa_address_space_io(isa),
579 d->base + (8 << d->dshift), &d->cont_io);
580
581 for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
582 d->regs[i].transfer_handler = i8257_phony_handler;
583 }
584
585 d->dma_bh = qemu_bh_new(i8257_dma_run, d);
586 }
587
588 static Property i8257_properties[] = {
589 DEFINE_PROP_INT32("base", I8257State, base, 0x00),
590 DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
591 DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
592 DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
593 DEFINE_PROP_END_OF_LIST()
594 };
595
i8257_class_init(ObjectClass * klass,void * data)596 static void i8257_class_init(ObjectClass *klass, void *data)
597 {
598 DeviceClass *dc = DEVICE_CLASS(klass);
599 IsaDmaClass *idc = ISADMA_CLASS(klass);
600
601 dc->realize = i8257_realize;
602 dc->reset = i8257_reset;
603 dc->vmsd = &vmstate_i8257;
604 device_class_set_props(dc, i8257_properties);
605
606 idc->has_autoinitialization = i8257_dma_has_autoinitialization;
607 idc->read_memory = i8257_dma_read_memory;
608 idc->write_memory = i8257_dma_write_memory;
609 idc->hold_DREQ = i8257_dma_hold_DREQ;
610 idc->release_DREQ = i8257_dma_release_DREQ;
611 idc->schedule = i8257_dma_schedule;
612 idc->register_channel = i8257_dma_register_channel;
613 /* Reason: needs to be wired up by isa_bus_dma() to work */
614 dc->user_creatable = false;
615 }
616
617 static const TypeInfo i8257_info = {
618 .name = TYPE_I8257,
619 .parent = TYPE_ISA_DEVICE,
620 .instance_size = sizeof(I8257State),
621 .class_init = i8257_class_init,
622 .interfaces = (InterfaceInfo[]) {
623 { TYPE_ISADMA },
624 { }
625 }
626 };
627
i8257_register_types(void)628 static void i8257_register_types(void)
629 {
630 type_register_static(&i8257_info);
631 }
632
type_init(i8257_register_types)633 type_init(i8257_register_types)
634
635 void i8257_dma_init(Object *parent, ISABus *bus, bool high_page_enable)
636 {
637 ISADevice *isa1, *isa2;
638 DeviceState *d;
639
640 isa1 = isa_new(TYPE_I8257);
641 object_property_add_child(parent, "dma[*]", OBJECT(isa1));
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 isa_realize_and_unref(isa1, bus, &error_fatal);
648
649 isa2 = isa_new(TYPE_I8257);
650 object_property_add_child(parent, "dma[*]", OBJECT(isa2));
651 d = DEVICE(isa2);
652 qdev_prop_set_int32(d, "base", 0xc0);
653 qdev_prop_set_int32(d, "page-base", 0x88);
654 qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
655 qdev_prop_set_int32(d, "dshift", 1);
656 isa_realize_and_unref(isa2, bus, &error_fatal);
657
658 isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
659 }
660