xref: /openbmc/qemu/hw/dma/i8257.c (revision a36544d3)
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 #include "qemu/osdep.h"
25 #include "hw/hw.h"
26 #include "hw/isa/isa.h"
27 #include "hw/dma/i8257.h"
28 #include "qemu/main-loop.h"
29 #include "trace.h"
30 
31 #define I8257(obj) \
32     OBJECT_CHECK(I8257State, (obj), TYPE_I8257)
33 
34 /* #define DEBUG_DMA */
35 
36 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
37 #ifdef DEBUG_DMA
38 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
39 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
40 #else
41 #define linfo(...)
42 #define ldebug(...)
43 #endif
44 
45 #define ADDR 0
46 #define COUNT 1
47 
48 enum {
49     CMD_MEMORY_TO_MEMORY = 0x01,
50     CMD_FIXED_ADDRESS    = 0x02,
51     CMD_BLOCK_CONTROLLER = 0x04,
52     CMD_COMPRESSED_TIME  = 0x08,
53     CMD_CYCLIC_PRIORITY  = 0x10,
54     CMD_EXTENDED_WRITE   = 0x20,
55     CMD_LOW_DREQ         = 0x40,
56     CMD_LOW_DACK         = 0x80,
57     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
58     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
59     | CMD_LOW_DREQ | CMD_LOW_DACK
60 
61 };
62 
63 static void i8257_dma_run(void *opaque);
64 
65 static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
66 
67 static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
68 {
69     I8257State *d = opaque;
70     int ichan;
71 
72     ichan = channels[nport & 7];
73     if (-1 == ichan) {
74         dolog ("invalid channel %#x %#x\n", nport, data);
75         return;
76     }
77     d->regs[ichan].page = data;
78 }
79 
80 static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
81 {
82     I8257State *d = opaque;
83     int ichan;
84 
85     ichan = channels[nport & 7];
86     if (-1 == ichan) {
87         dolog ("invalid channel %#x %#x\n", nport, data);
88         return;
89     }
90     d->regs[ichan].pageh = data;
91 }
92 
93 static uint32_t i8257_read_page(void *opaque, uint32_t nport)
94 {
95     I8257State *d = opaque;
96     int ichan;
97 
98     ichan = channels[nport & 7];
99     if (-1 == ichan) {
100         dolog ("invalid channel read %#x\n", nport);
101         return 0;
102     }
103     return d->regs[ichan].page;
104 }
105 
106 static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
107 {
108     I8257State *d = opaque;
109     int ichan;
110 
111     ichan = channels[nport & 7];
112     if (-1 == ichan) {
113         dolog ("invalid channel read %#x\n", nport);
114         return 0;
115     }
116     return d->regs[ichan].pageh;
117 }
118 
119 static inline void i8257_init_chan(I8257State *d, int ichan)
120 {
121     I8257Regs *r;
122 
123     r = d->regs + ichan;
124     r->now[ADDR] = r->base[ADDR] << d->dshift;
125     r->now[COUNT] = 0;
126 }
127 
128 static inline int i8257_getff(I8257State *d)
129 {
130     int ff;
131 
132     ff = d->flip_flop;
133     d->flip_flop = !ff;
134     return ff;
135 }
136 
137 static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
138 {
139     I8257State *d = opaque;
140     int ichan, nreg, iport, ff, val, dir;
141     I8257Regs *r;
142 
143     iport = (nport >> d->dshift) & 0x0f;
144     ichan = iport >> 1;
145     nreg = iport & 1;
146     r = d->regs + ichan;
147 
148     dir = ((r->mode >> 5) & 1) ? -1 : 1;
149     ff = i8257_getff(d);
150     if (nreg)
151         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
152     else
153         val = r->now[ADDR] + r->now[COUNT] * dir;
154 
155     ldebug ("read_chan %#x -> %d\n", iport, val);
156     return (val >> (d->dshift + (ff << 3))) & 0xff;
157 }
158 
159 static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
160                              unsigned int size)
161 {
162     I8257State *d = opaque;
163     int iport, ichan, nreg;
164     I8257Regs *r;
165 
166     iport = (nport >> d->dshift) & 0x0f;
167     ichan = iport >> 1;
168     nreg = iport & 1;
169     r = d->regs + ichan;
170     if (i8257_getff(d)) {
171         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
172         i8257_init_chan(d, ichan);
173     } else {
174         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
175     }
176 }
177 
178 static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
179                              unsigned int size)
180 {
181     I8257State *d = opaque;
182     int iport, ichan = 0;
183 
184     iport = (nport >> d->dshift) & 0x0f;
185     switch (iport) {
186     case 0x00:                  /* command */
187         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
188             dolog("command %"PRIx64" not supported\n", data);
189             return;
190         }
191         d->command = data;
192         break;
193 
194     case 0x01:
195         ichan = data & 3;
196         if (data & 4) {
197             d->status |= 1 << (ichan + 4);
198         }
199         else {
200             d->status &= ~(1 << (ichan + 4));
201         }
202         d->status &= ~(1 << ichan);
203         i8257_dma_run(d);
204         break;
205 
206     case 0x02:                  /* single mask */
207         if (data & 4)
208             d->mask |= 1 << (data & 3);
209         else
210             d->mask &= ~(1 << (data & 3));
211         i8257_dma_run(d);
212         break;
213 
214     case 0x03:                  /* mode */
215         {
216             ichan = data & 3;
217 #ifdef DEBUG_DMA
218             {
219                 int op, ai, dir, opmode;
220                 op = (data >> 2) & 3;
221                 ai = (data >> 4) & 1;
222                 dir = (data >> 5) & 1;
223                 opmode = (data >> 6) & 3;
224 
225                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
226                        ichan, op, ai, dir, opmode);
227             }
228 #endif
229             d->regs[ichan].mode = data;
230             break;
231         }
232 
233     case 0x04:                  /* clear flip flop */
234         d->flip_flop = 0;
235         break;
236 
237     case 0x05:                  /* reset */
238         d->flip_flop = 0;
239         d->mask = ~0;
240         d->status = 0;
241         d->command = 0;
242         break;
243 
244     case 0x06:                  /* clear mask for all channels */
245         d->mask = 0;
246         i8257_dma_run(d);
247         break;
248 
249     case 0x07:                  /* write mask for all channels */
250         d->mask = data;
251         i8257_dma_run(d);
252         break;
253 
254     default:
255         dolog ("unknown iport %#x\n", iport);
256         break;
257     }
258 
259 #ifdef DEBUG_DMA
260     if (0xc != iport) {
261         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
262                nport, ichan, data);
263     }
264 #endif
265 }
266 
267 static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
268 {
269     I8257State *d = opaque;
270     int iport, val;
271 
272     iport = (nport >> d->dshift) & 0x0f;
273     switch (iport) {
274     case 0x00:                  /* status */
275         val = d->status;
276         d->status &= 0xf0;
277         break;
278     case 0x01:                  /* mask */
279         val = d->mask;
280         break;
281     default:
282         val = 0;
283         break;
284     }
285 
286     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
287     return val;
288 }
289 
290 static IsaDmaTransferMode i8257_dma_get_transfer_mode(IsaDma *obj, int nchan)
291 {
292     I8257State *d = I8257(obj);
293     return (d->regs[nchan & 3].mode >> 2) & 3;
294 }
295 
296 static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
297 {
298     I8257State *d = I8257(obj);
299     return (d->regs[nchan & 3].mode >> 4) & 1;
300 }
301 
302 static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
303 {
304     I8257State *d = I8257(obj);
305     int ichan;
306 
307     ichan = nchan & 3;
308     d->status |= 1 << (ichan + 4);
309     i8257_dma_run(d);
310 }
311 
312 static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
313 {
314     I8257State *d = I8257(obj);
315     int ichan;
316 
317     ichan = nchan & 3;
318     d->status &= ~(1 << (ichan + 4));
319     i8257_dma_run(d);
320 }
321 
322 static void i8257_channel_run(I8257State *d, int ichan)
323 {
324     int ncont = d->dshift;
325     int n;
326     I8257Regs *r = &d->regs[ichan];
327 #ifdef DEBUG_DMA
328     int dir, opmode;
329 
330     dir = (r->mode >> 5) & 1;
331     opmode = (r->mode >> 6) & 3;
332 
333     if (dir) {
334         dolog ("DMA in address decrement mode\n");
335     }
336     if (opmode != 1) {
337         dolog ("DMA not in single mode select %#x\n", opmode);
338     }
339 #endif
340 
341     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
342                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
343     r->now[COUNT] = n;
344     ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
345     if (n == (r->base[COUNT] + 1) << ncont) {
346         ldebug("transfer done\n");
347         d->status |= (1 << ichan);
348     }
349 }
350 
351 static void i8257_dma_run(void *opaque)
352 {
353     I8257State *d = opaque;
354     int ichan;
355     int rearm = 0;
356 
357     if (d->running) {
358         rearm = 1;
359         goto out;
360     } else {
361         d->running = 1;
362     }
363 
364     for (ichan = 0; ichan < 4; ichan++) {
365         int mask;
366 
367         mask = 1 << ichan;
368 
369         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
370             i8257_channel_run(d, ichan);
371             rearm = 1;
372         }
373     }
374 
375     d->running = 0;
376 out:
377     if (rearm) {
378         qemu_bh_schedule_idle(d->dma_bh);
379         d->dma_bh_scheduled = true;
380     }
381 }
382 
383 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
384                                        IsaDmaTransferHandler transfer_handler,
385                                        void *opaque)
386 {
387     I8257State *d = I8257(obj);
388     I8257Regs *r;
389     int ichan;
390 
391     ichan = nchan & 3;
392 
393     r = d->regs + ichan;
394     r->transfer_handler = transfer_handler;
395     r->opaque = opaque;
396 }
397 
398 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
399                                  int len)
400 {
401     I8257State *d = I8257(obj);
402     I8257Regs *r = &d->regs[nchan & 3];
403     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
404 
405     if (r->mode & 0x20) {
406         int i;
407         uint8_t *p = buf;
408 
409         cpu_physical_memory_read (addr - pos - len, buf, len);
410         /* What about 16bit transfers? */
411         for (i = 0; i < len >> 1; i++) {
412             uint8_t b = p[len - i - 1];
413             p[i] = b;
414         }
415     }
416     else
417         cpu_physical_memory_read (addr + pos, buf, len);
418 
419     return len;
420 }
421 
422 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
423                                  int len)
424 {
425     I8257State *s = I8257(obj);
426     I8257Regs *r = &s->regs[nchan & 3];
427     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
428 
429     if (r->mode & 0x20) {
430         int i;
431         uint8_t *p = buf;
432 
433         cpu_physical_memory_write (addr - pos - len, buf, len);
434         /* What about 16bit transfers? */
435         for (i = 0; i < len; i++) {
436             uint8_t b = p[len - i - 1];
437             p[i] = b;
438         }
439     }
440     else
441         cpu_physical_memory_write (addr + pos, buf, len);
442 
443     return len;
444 }
445 
446 /* request the emulator to transfer a new DMA memory block ASAP (even
447  * if the idle bottom half would not have exited the iothread yet).
448  */
449 static void i8257_dma_schedule(IsaDma *obj)
450 {
451     I8257State *d = I8257(obj);
452     if (d->dma_bh_scheduled) {
453         qemu_notify_event();
454     }
455 }
456 
457 static void i8257_reset(DeviceState *dev)
458 {
459     I8257State *d = I8257(dev);
460     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
461 }
462 
463 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
464                                int dma_len)
465 {
466     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
467     return dma_pos;
468 }
469 
470 
471 static const MemoryRegionOps channel_io_ops = {
472     .read = i8257_read_chan,
473     .write = i8257_write_chan,
474     .endianness = DEVICE_NATIVE_ENDIAN,
475     .impl = {
476         .min_access_size = 1,
477         .max_access_size = 1,
478     },
479 };
480 
481 /* IOport from page_base */
482 static const MemoryRegionPortio page_portio_list[] = {
483     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
484     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
485     PORTIO_END_OF_LIST(),
486 };
487 
488 /* IOport from pageh_base */
489 static const MemoryRegionPortio pageh_portio_list[] = {
490     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
491     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
492     PORTIO_END_OF_LIST(),
493 };
494 
495 static const MemoryRegionOps cont_io_ops = {
496     .read = i8257_read_cont,
497     .write = i8257_write_cont,
498     .endianness = DEVICE_NATIVE_ENDIAN,
499     .impl = {
500         .min_access_size = 1,
501         .max_access_size = 1,
502     },
503 };
504 
505 static const VMStateDescription vmstate_i8257_regs = {
506     .name = "dma_regs",
507     .version_id = 1,
508     .minimum_version_id = 1,
509     .fields = (VMStateField[]) {
510         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
511         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
512         VMSTATE_UINT8(mode, I8257Regs),
513         VMSTATE_UINT8(page, I8257Regs),
514         VMSTATE_UINT8(pageh, I8257Regs),
515         VMSTATE_UINT8(dack, I8257Regs),
516         VMSTATE_UINT8(eop, I8257Regs),
517         VMSTATE_END_OF_LIST()
518     }
519 };
520 
521 static int i8257_post_load(void *opaque, int version_id)
522 {
523     I8257State *d = opaque;
524     i8257_dma_run(d);
525 
526     return 0;
527 }
528 
529 static const VMStateDescription vmstate_i8257 = {
530     .name = "dma",
531     .version_id = 1,
532     .minimum_version_id = 1,
533     .post_load = i8257_post_load,
534     .fields = (VMStateField[]) {
535         VMSTATE_UINT8(command, I8257State),
536         VMSTATE_UINT8(mask, I8257State),
537         VMSTATE_UINT8(flip_flop, I8257State),
538         VMSTATE_INT32(dshift, I8257State),
539         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
540                              I8257Regs),
541         VMSTATE_END_OF_LIST()
542     }
543 };
544 
545 static void i8257_realize(DeviceState *dev, Error **errp)
546 {
547     ISADevice *isa = ISA_DEVICE(dev);
548     I8257State *d = I8257(dev);
549     int i;
550 
551     memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d,
552                           "dma-chan", 8 << d->dshift);
553     memory_region_add_subregion(isa_address_space_io(isa),
554                                 d->base, &d->channel_io);
555 
556     isa_register_portio_list(isa, &d->portio_page,
557                              d->page_base, page_portio_list, d,
558                              "dma-page");
559     if (d->pageh_base >= 0) {
560         isa_register_portio_list(isa, &d->portio_pageh,
561                                  d->pageh_base, pageh_portio_list, d,
562                                  "dma-pageh");
563     }
564 
565     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
566                           "dma-cont", 8 << d->dshift);
567     memory_region_add_subregion(isa_address_space_io(isa),
568                                 d->base + (8 << d->dshift), &d->cont_io);
569 
570     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
571         d->regs[i].transfer_handler = i8257_phony_handler;
572     }
573 
574     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
575 }
576 
577 static Property i8257_properties[] = {
578     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
579     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
580     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
581     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
582     DEFINE_PROP_END_OF_LIST()
583 };
584 
585 static void i8257_class_init(ObjectClass *klass, void *data)
586 {
587     DeviceClass *dc = DEVICE_CLASS(klass);
588     IsaDmaClass *idc = ISADMA_CLASS(klass);
589 
590     dc->realize = i8257_realize;
591     dc->reset = i8257_reset;
592     dc->vmsd = &vmstate_i8257;
593     dc->props = i8257_properties;
594 
595     idc->get_transfer_mode = i8257_dma_get_transfer_mode;
596     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
597     idc->read_memory = i8257_dma_read_memory;
598     idc->write_memory = i8257_dma_write_memory;
599     idc->hold_DREQ = i8257_dma_hold_DREQ;
600     idc->release_DREQ = i8257_dma_release_DREQ;
601     idc->schedule = i8257_dma_schedule;
602     idc->register_channel = i8257_dma_register_channel;
603     /* Reason: needs to be wired up by isa_bus_dma() to work */
604     dc->user_creatable = false;
605 }
606 
607 static const TypeInfo i8257_info = {
608     .name = TYPE_I8257,
609     .parent = TYPE_ISA_DEVICE,
610     .instance_size = sizeof(I8257State),
611     .class_init = i8257_class_init,
612     .interfaces = (InterfaceInfo[]) {
613         { TYPE_ISADMA },
614         { }
615     }
616 };
617 
618 static void i8257_register_types(void)
619 {
620     type_register_static(&i8257_info);
621 }
622 
623 type_init(i8257_register_types)
624 
625 void i8257_dma_init(ISABus *bus, bool high_page_enable)
626 {
627     ISADevice *isa1, *isa2;
628     DeviceState *d;
629 
630     isa1 = isa_create(bus, TYPE_I8257);
631     d = DEVICE(isa1);
632     qdev_prop_set_int32(d, "base", 0x00);
633     qdev_prop_set_int32(d, "page-base", 0x80);
634     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
635     qdev_prop_set_int32(d, "dshift", 0);
636     qdev_init_nofail(d);
637 
638     isa2 = isa_create(bus, TYPE_I8257);
639     d = DEVICE(isa2);
640     qdev_prop_set_int32(d, "base", 0xc0);
641     qdev_prop_set_int32(d, "page-base", 0x88);
642     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
643     qdev_prop_set_int32(d, "dshift", 1);
644     qdev_init_nofail(d);
645 
646     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
647 }
648