xref: /openbmc/qemu/hw/dma/i8257.c (revision 500eb6db)
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/hw.h"
27 #include "hw/isa/isa.h"
28 #include "hw/dma/i8257.h"
29 #include "qemu/main-loop.h"
30 #include "qemu/module.h"
31 #include "qemu/log.h"
32 #include "trace.h"
33 
34 #define I8257(obj) \
35     OBJECT_CHECK(I8257State, (obj), TYPE_I8257)
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
294 static IsaDmaTransferMode i8257_dma_get_transfer_mode(IsaDma *obj, int nchan)
295 {
296     I8257State *d = I8257(obj);
297     return (d->regs[nchan & 3].mode >> 2) & 3;
298 }
299 
300 static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
301 {
302     I8257State *d = I8257(obj);
303     return (d->regs[nchan & 3].mode >> 4) & 1;
304 }
305 
306 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
307 {
308     I8257State *d = I8257(obj);
309     int ichan;
310 
311     ichan = nchan & 3;
312     d->status |= 1 << (ichan + 4);
313     i8257_dma_run(d);
314 }
315 
316 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
317 {
318     I8257State *d = I8257(obj);
319     int ichan;
320 
321     ichan = nchan & 3;
322     d->status &= ~(1 << (ichan + 4));
323     i8257_dma_run(d);
324 }
325 
326 static void i8257_channel_run(I8257State *d, int ichan)
327 {
328     int ncont = d->dshift;
329     int n;
330     I8257Regs *r = &d->regs[ichan];
331 #ifdef DEBUG_DMA
332     int dir, opmode;
333 
334     dir = (r->mode >> 5) & 1;
335     opmode = (r->mode >> 6) & 3;
336 
337     if (dir) {
338         dolog ("DMA in address decrement mode\n");
339     }
340     if (opmode != 1) {
341         dolog ("DMA not in single mode select %#x\n", opmode);
342     }
343 #endif
344 
345     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
346                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
347     r->now[COUNT] = n;
348     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
349     if (n == (r->base[COUNT] + 1) << ncont) {
350         ldebug("transfer done\n");
351         d->status |= (1 << ichan);
352     }
353 }
354 
355 static void i8257_dma_run(void *opaque)
356 {
357     I8257State *d = opaque;
358     int ichan;
359     int rearm = 0;
360 
361     if (d->running) {
362         rearm = 1;
363         goto out;
364     } else {
365         d->running = 1;
366     }
367 
368     for (ichan = 0; ichan < 4; ichan++) {
369         int mask;
370 
371         mask = 1 << ichan;
372 
373         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
374             i8257_channel_run(d, ichan);
375             rearm = 1;
376         }
377     }
378 
379     d->running = 0;
380 out:
381     if (rearm) {
382         qemu_bh_schedule_idle(d->dma_bh);
383         d->dma_bh_scheduled = true;
384     }
385 }
386 
387 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
388                                        IsaDmaTransferHandler transfer_handler,
389                                        void *opaque)
390 {
391     I8257State *d = I8257(obj);
392     I8257Regs *r;
393     int ichan;
394 
395     ichan = nchan & 3;
396 
397     r = d->regs + ichan;
398     r->transfer_handler = transfer_handler;
399     r->opaque = opaque;
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 (r->mode & 0x20) {
410         int i;
411         uint8_t *p = buf;
412 
413         cpu_physical_memory_read (addr - pos - len, buf, len);
414         /* What about 16bit transfers? */
415         for (i = 0; i < len >> 1; i++) {
416             uint8_t b = p[len - i - 1];
417             p[i] = b;
418         }
419     }
420     else
421         cpu_physical_memory_read (addr + pos, buf, len);
422 
423     return len;
424 }
425 
426 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
427                                  int len)
428 {
429     I8257State *s = I8257(obj);
430     I8257Regs *r = &s->regs[nchan & 3];
431     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
432 
433     if (r->mode & 0x20) {
434         int i;
435         uint8_t *p = buf;
436 
437         cpu_physical_memory_write (addr - pos - len, buf, len);
438         /* What about 16bit transfers? */
439         for (i = 0; i < len; i++) {
440             uint8_t b = p[len - i - 1];
441             p[i] = b;
442         }
443     }
444     else
445         cpu_physical_memory_write (addr + pos, buf, len);
446 
447     return len;
448 }
449 
450 /* request the emulator to transfer a new DMA memory block ASAP (even
451  * if the idle bottom half would not have exited the iothread yet).
452  */
453 static void i8257_dma_schedule(IsaDma *obj)
454 {
455     I8257State *d = I8257(obj);
456     if (d->dma_bh_scheduled) {
457         qemu_notify_event();
458     }
459 }
460 
461 static void i8257_reset(DeviceState *dev)
462 {
463     I8257State *d = I8257(dev);
464     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
465 }
466 
467 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
468                                int dma_len)
469 {
470     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
471     return dma_pos;
472 }
473 
474 
475 static const MemoryRegionOps channel_io_ops = {
476     .read = i8257_read_chan,
477     .write = i8257_write_chan,
478     .endianness = DEVICE_NATIVE_ENDIAN,
479     .impl = {
480         .min_access_size = 1,
481         .max_access_size = 1,
482     },
483 };
484 
485 /* IOport from page_base */
486 static const MemoryRegionPortio page_portio_list[] = {
487     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
488     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
489     PORTIO_END_OF_LIST(),
490 };
491 
492 /* IOport from pageh_base */
493 static const MemoryRegionPortio pageh_portio_list[] = {
494     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
495     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
496     PORTIO_END_OF_LIST(),
497 };
498 
499 static const MemoryRegionOps cont_io_ops = {
500     .read = i8257_read_cont,
501     .write = i8257_write_cont,
502     .endianness = DEVICE_NATIVE_ENDIAN,
503     .impl = {
504         .min_access_size = 1,
505         .max_access_size = 1,
506     },
507 };
508 
509 static const VMStateDescription vmstate_i8257_regs = {
510     .name = "dma_regs",
511     .version_id = 1,
512     .minimum_version_id = 1,
513     .fields = (VMStateField[]) {
514         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
515         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
516         VMSTATE_UINT8(mode, I8257Regs),
517         VMSTATE_UINT8(page, I8257Regs),
518         VMSTATE_UINT8(pageh, I8257Regs),
519         VMSTATE_UINT8(dack, I8257Regs),
520         VMSTATE_UINT8(eop, I8257Regs),
521         VMSTATE_END_OF_LIST()
522     }
523 };
524 
525 static int i8257_post_load(void *opaque, int version_id)
526 {
527     I8257State *d = opaque;
528     i8257_dma_run(d);
529 
530     return 0;
531 }
532 
533 static const VMStateDescription vmstate_i8257 = {
534     .name = "dma",
535     .version_id = 1,
536     .minimum_version_id = 1,
537     .post_load = i8257_post_load,
538     .fields = (VMStateField[]) {
539         VMSTATE_UINT8(command, I8257State),
540         VMSTATE_UINT8(mask, I8257State),
541         VMSTATE_UINT8(flip_flop, I8257State),
542         VMSTATE_INT32(dshift, I8257State),
543         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
544                              I8257Regs),
545         VMSTATE_END_OF_LIST()
546     }
547 };
548 
549 static void i8257_realize(DeviceState *dev, Error **errp)
550 {
551     ISADevice *isa = ISA_DEVICE(dev);
552     I8257State *d = I8257(dev);
553     int i;
554 
555     memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d,
556                           "dma-chan", 8 << d->dshift);
557     memory_region_add_subregion(isa_address_space_io(isa),
558                                 d->base, &d->channel_io);
559 
560     isa_register_portio_list(isa, &d->portio_page,
561                              d->page_base, page_portio_list, d,
562                              "dma-page");
563     if (d->pageh_base >= 0) {
564         isa_register_portio_list(isa, &d->portio_pageh,
565                                  d->pageh_base, pageh_portio_list, d,
566                                  "dma-pageh");
567     }
568 
569     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
570                           "dma-cont", 8 << d->dshift);
571     memory_region_add_subregion(isa_address_space_io(isa),
572                                 d->base + (8 << d->dshift), &d->cont_io);
573 
574     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
575         d->regs[i].transfer_handler = i8257_phony_handler;
576     }
577 
578     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
579 }
580 
581 static Property i8257_properties[] = {
582     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
583     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
584     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
585     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
586     DEFINE_PROP_END_OF_LIST()
587 };
588 
589 static void i8257_class_init(ObjectClass *klass, void *data)
590 {
591     DeviceClass *dc = DEVICE_CLASS(klass);
592     IsaDmaClass *idc = ISADMA_CLASS(klass);
593 
594     dc->realize = i8257_realize;
595     dc->reset = i8257_reset;
596     dc->vmsd = &vmstate_i8257;
597     dc->props = i8257_properties;
598 
599     idc->get_transfer_mode = i8257_dma_get_transfer_mode;
600     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
601     idc->read_memory = i8257_dma_read_memory;
602     idc->write_memory = i8257_dma_write_memory;
603     idc->hold_DREQ = i8257_dma_hold_DREQ;
604     idc->release_DREQ = i8257_dma_release_DREQ;
605     idc->schedule = i8257_dma_schedule;
606     idc->register_channel = i8257_dma_register_channel;
607     /* Reason: needs to be wired up by isa_bus_dma() to work */
608     dc->user_creatable = false;
609 }
610 
611 static const TypeInfo i8257_info = {
612     .name = TYPE_I8257,
613     .parent = TYPE_ISA_DEVICE,
614     .instance_size = sizeof(I8257State),
615     .class_init = i8257_class_init,
616     .interfaces = (InterfaceInfo[]) {
617         { TYPE_ISADMA },
618         { }
619     }
620 };
621 
622 static void i8257_register_types(void)
623 {
624     type_register_static(&i8257_info);
625 }
626 
627 type_init(i8257_register_types)
628 
629 void i8257_dma_init(ISABus *bus, bool high_page_enable)
630 {
631     ISADevice *isa1, *isa2;
632     DeviceState *d;
633 
634     isa1 = isa_create(bus, TYPE_I8257);
635     d = DEVICE(isa1);
636     qdev_prop_set_int32(d, "base", 0x00);
637     qdev_prop_set_int32(d, "page-base", 0x80);
638     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
639     qdev_prop_set_int32(d, "dshift", 0);
640     qdev_init_nofail(d);
641 
642     isa2 = isa_create(bus, TYPE_I8257);
643     d = DEVICE(isa2);
644     qdev_prop_set_int32(d, "base", 0xc0);
645     qdev_prop_set_int32(d, "page-base", 0x88);
646     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
647     qdev_prop_set_int32(d, "dshift", 1);
648     qdev_init_nofail(d);
649 
650     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
651 }
652