xref: /openbmc/qemu/hw/dma/i8257.c (revision 354908ce)
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 #define I8257(obj) \
37     OBJECT_CHECK(I8257State, (obj), TYPE_I8257)
38 
39 /* #define DEBUG_DMA */
40 
41 #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
42 #ifdef DEBUG_DMA
43 #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
44 #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
45 #else
46 #define linfo(...)
47 #define ldebug(...)
48 #endif
49 
50 #define ADDR 0
51 #define COUNT 1
52 
53 enum {
54     CMD_MEMORY_TO_MEMORY = 0x01,
55     CMD_FIXED_ADDRESS    = 0x02,
56     CMD_BLOCK_CONTROLLER = 0x04,
57     CMD_COMPRESSED_TIME  = 0x08,
58     CMD_CYCLIC_PRIORITY  = 0x10,
59     CMD_EXTENDED_WRITE   = 0x20,
60     CMD_LOW_DREQ         = 0x40,
61     CMD_LOW_DACK         = 0x80,
62     CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
63     | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
64     | CMD_LOW_DREQ | CMD_LOW_DACK
65 
66 };
67 
68 static void i8257_dma_run(void *opaque);
69 
70 static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
71 
72 static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
73 {
74     I8257State *d = opaque;
75     int ichan;
76 
77     ichan = channels[nport & 7];
78     if (-1 == ichan) {
79         dolog ("invalid channel %#x %#x\n", nport, data);
80         return;
81     }
82     d->regs[ichan].page = data;
83 }
84 
85 static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
86 {
87     I8257State *d = opaque;
88     int ichan;
89 
90     ichan = channels[nport & 7];
91     if (-1 == ichan) {
92         dolog ("invalid channel %#x %#x\n", nport, data);
93         return;
94     }
95     d->regs[ichan].pageh = data;
96 }
97 
98 static uint32_t i8257_read_page(void *opaque, uint32_t nport)
99 {
100     I8257State *d = opaque;
101     int ichan;
102 
103     ichan = channels[nport & 7];
104     if (-1 == ichan) {
105         dolog ("invalid channel read %#x\n", nport);
106         return 0;
107     }
108     return d->regs[ichan].page;
109 }
110 
111 static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
112 {
113     I8257State *d = opaque;
114     int ichan;
115 
116     ichan = channels[nport & 7];
117     if (-1 == ichan) {
118         dolog ("invalid channel read %#x\n", nport);
119         return 0;
120     }
121     return d->regs[ichan].pageh;
122 }
123 
124 static inline void i8257_init_chan(I8257State *d, int ichan)
125 {
126     I8257Regs *r;
127 
128     r = d->regs + ichan;
129     r->now[ADDR] = r->base[ADDR] << d->dshift;
130     r->now[COUNT] = 0;
131 }
132 
133 static inline int i8257_getff(I8257State *d)
134 {
135     int ff;
136 
137     ff = d->flip_flop;
138     d->flip_flop = !ff;
139     return ff;
140 }
141 
142 static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
143 {
144     I8257State *d = opaque;
145     int ichan, nreg, iport, ff, val, dir;
146     I8257Regs *r;
147 
148     iport = (nport >> d->dshift) & 0x0f;
149     ichan = iport >> 1;
150     nreg = iport & 1;
151     r = d->regs + ichan;
152 
153     dir = ((r->mode >> 5) & 1) ? -1 : 1;
154     ff = i8257_getff(d);
155     if (nreg)
156         val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
157     else
158         val = r->now[ADDR] + r->now[COUNT] * dir;
159 
160     ldebug ("read_chan %#x -> %d\n", iport, val);
161     return (val >> (d->dshift + (ff << 3))) & 0xff;
162 }
163 
164 static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
165                              unsigned int size)
166 {
167     I8257State *d = opaque;
168     int iport, ichan, nreg;
169     I8257Regs *r;
170 
171     iport = (nport >> d->dshift) & 0x0f;
172     ichan = iport >> 1;
173     nreg = iport & 1;
174     r = d->regs + ichan;
175     if (i8257_getff(d)) {
176         r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
177         i8257_init_chan(d, ichan);
178     } else {
179         r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
180     }
181 }
182 
183 static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
184                              unsigned int size)
185 {
186     I8257State *d = opaque;
187     int iport, ichan = 0;
188 
189     iport = (nport >> d->dshift) & 0x0f;
190     switch (iport) {
191     case 0x00:                  /* command */
192         if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
193             qemu_log_mask(LOG_UNIMP, "%s: cmd 0x%02"PRIx64" not supported\n",
194                           __func__, data);
195             return;
196         }
197         d->command = data;
198         break;
199 
200     case 0x01:
201         ichan = data & 3;
202         if (data & 4) {
203             d->status |= 1 << (ichan + 4);
204         }
205         else {
206             d->status &= ~(1 << (ichan + 4));
207         }
208         d->status &= ~(1 << ichan);
209         i8257_dma_run(d);
210         break;
211 
212     case 0x02:                  /* single mask */
213         if (data & 4)
214             d->mask |= 1 << (data & 3);
215         else
216             d->mask &= ~(1 << (data & 3));
217         i8257_dma_run(d);
218         break;
219 
220     case 0x03:                  /* mode */
221         {
222             ichan = data & 3;
223 #ifdef DEBUG_DMA
224             {
225                 int op, ai, dir, opmode;
226                 op = (data >> 2) & 3;
227                 ai = (data >> 4) & 1;
228                 dir = (data >> 5) & 1;
229                 opmode = (data >> 6) & 3;
230 
231                 linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
232                        ichan, op, ai, dir, opmode);
233             }
234 #endif
235             d->regs[ichan].mode = data;
236             break;
237         }
238 
239     case 0x04:                  /* clear flip flop */
240         d->flip_flop = 0;
241         break;
242 
243     case 0x05:                  /* reset */
244         d->flip_flop = 0;
245         d->mask = ~0;
246         d->status = 0;
247         d->command = 0;
248         break;
249 
250     case 0x06:                  /* clear mask for all channels */
251         d->mask = 0;
252         i8257_dma_run(d);
253         break;
254 
255     case 0x07:                  /* write mask for all channels */
256         d->mask = data;
257         i8257_dma_run(d);
258         break;
259 
260     default:
261         dolog ("unknown iport %#x\n", iport);
262         break;
263     }
264 
265 #ifdef DEBUG_DMA
266     if (0xc != iport) {
267         linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
268                nport, ichan, data);
269     }
270 #endif
271 }
272 
273 static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
274 {
275     I8257State *d = opaque;
276     int iport, val;
277 
278     iport = (nport >> d->dshift) & 0x0f;
279     switch (iport) {
280     case 0x00:                  /* status */
281         val = d->status;
282         d->status &= 0xf0;
283         break;
284     case 0x01:                  /* mask */
285         val = d->mask;
286         break;
287     default:
288         val = 0;
289         break;
290     }
291 
292     ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
293     return val;
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 bool i8257_is_verify_transfer(I8257Regs *r)
399 {
400     return (r->mode & 0x0c) == 0;
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 (i8257_is_verify_transfer(r)) {
411         return len;
412     }
413 
414     if (r->mode & 0x20) {
415         int i;
416         uint8_t *p = buf;
417 
418         cpu_physical_memory_read (addr - pos - len, buf, len);
419         /* What about 16bit transfers? */
420         for (i = 0; i < len >> 1; i++) {
421             uint8_t b = p[len - i - 1];
422             p[i] = b;
423         }
424     }
425     else
426         cpu_physical_memory_read (addr + pos, buf, len);
427 
428     return len;
429 }
430 
431 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
432                                  int len)
433 {
434     I8257State *s = I8257(obj);
435     I8257Regs *r = &s->regs[nchan & 3];
436     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
437 
438     if (i8257_is_verify_transfer(r)) {
439         return len;
440     }
441 
442     if (r->mode & 0x20) {
443         int i;
444         uint8_t *p = buf;
445 
446         cpu_physical_memory_write (addr - pos - len, buf, len);
447         /* What about 16bit transfers? */
448         for (i = 0; i < len; i++) {
449             uint8_t b = p[len - i - 1];
450             p[i] = b;
451         }
452     }
453     else
454         cpu_physical_memory_write (addr + pos, buf, len);
455 
456     return len;
457 }
458 
459 /* request the emulator to transfer a new DMA memory block ASAP (even
460  * if the idle bottom half would not have exited the iothread yet).
461  */
462 static void i8257_dma_schedule(IsaDma *obj)
463 {
464     I8257State *d = I8257(obj);
465     if (d->dma_bh_scheduled) {
466         qemu_notify_event();
467     }
468 }
469 
470 static void i8257_reset(DeviceState *dev)
471 {
472     I8257State *d = I8257(dev);
473     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
474 }
475 
476 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
477                                int dma_len)
478 {
479     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
480     return dma_pos;
481 }
482 
483 
484 static const MemoryRegionOps channel_io_ops = {
485     .read = i8257_read_chan,
486     .write = i8257_write_chan,
487     .endianness = DEVICE_NATIVE_ENDIAN,
488     .impl = {
489         .min_access_size = 1,
490         .max_access_size = 1,
491     },
492 };
493 
494 /* IOport from page_base */
495 static const MemoryRegionPortio page_portio_list[] = {
496     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
497     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
498     PORTIO_END_OF_LIST(),
499 };
500 
501 /* IOport from pageh_base */
502 static const MemoryRegionPortio pageh_portio_list[] = {
503     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
504     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
505     PORTIO_END_OF_LIST(),
506 };
507 
508 static const MemoryRegionOps cont_io_ops = {
509     .read = i8257_read_cont,
510     .write = i8257_write_cont,
511     .endianness = DEVICE_NATIVE_ENDIAN,
512     .impl = {
513         .min_access_size = 1,
514         .max_access_size = 1,
515     },
516 };
517 
518 static const VMStateDescription vmstate_i8257_regs = {
519     .name = "dma_regs",
520     .version_id = 1,
521     .minimum_version_id = 1,
522     .fields = (VMStateField[]) {
523         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
524         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
525         VMSTATE_UINT8(mode, I8257Regs),
526         VMSTATE_UINT8(page, I8257Regs),
527         VMSTATE_UINT8(pageh, I8257Regs),
528         VMSTATE_UINT8(dack, I8257Regs),
529         VMSTATE_UINT8(eop, I8257Regs),
530         VMSTATE_END_OF_LIST()
531     }
532 };
533 
534 static int i8257_post_load(void *opaque, int version_id)
535 {
536     I8257State *d = opaque;
537     i8257_dma_run(d);
538 
539     return 0;
540 }
541 
542 static const VMStateDescription vmstate_i8257 = {
543     .name = "dma",
544     .version_id = 1,
545     .minimum_version_id = 1,
546     .post_load = i8257_post_load,
547     .fields = (VMStateField[]) {
548         VMSTATE_UINT8(command, I8257State),
549         VMSTATE_UINT8(mask, I8257State),
550         VMSTATE_UINT8(flip_flop, I8257State),
551         VMSTATE_INT32(dshift, I8257State),
552         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
553                              I8257Regs),
554         VMSTATE_END_OF_LIST()
555     }
556 };
557 
558 static void i8257_realize(DeviceState *dev, Error **errp)
559 {
560     ISADevice *isa = ISA_DEVICE(dev);
561     I8257State *d = I8257(dev);
562     int i;
563 
564     memory_region_init_io(&d->channel_io, OBJECT(dev), &channel_io_ops, d,
565                           "dma-chan", 8 << d->dshift);
566     memory_region_add_subregion(isa_address_space_io(isa),
567                                 d->base, &d->channel_io);
568 
569     isa_register_portio_list(isa, &d->portio_page,
570                              d->page_base, page_portio_list, d,
571                              "dma-page");
572     if (d->pageh_base >= 0) {
573         isa_register_portio_list(isa, &d->portio_pageh,
574                                  d->pageh_base, pageh_portio_list, d,
575                                  "dma-pageh");
576     }
577 
578     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
579                           "dma-cont", 8 << d->dshift);
580     memory_region_add_subregion(isa_address_space_io(isa),
581                                 d->base + (8 << d->dshift), &d->cont_io);
582 
583     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
584         d->regs[i].transfer_handler = i8257_phony_handler;
585     }
586 
587     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
588 }
589 
590 static Property i8257_properties[] = {
591     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
592     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
593     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
594     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
595     DEFINE_PROP_END_OF_LIST()
596 };
597 
598 static void i8257_class_init(ObjectClass *klass, void *data)
599 {
600     DeviceClass *dc = DEVICE_CLASS(klass);
601     IsaDmaClass *idc = ISADMA_CLASS(klass);
602 
603     dc->realize = i8257_realize;
604     dc->reset = i8257_reset;
605     dc->vmsd = &vmstate_i8257;
606     device_class_set_props(dc, i8257_properties);
607 
608     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
609     idc->read_memory = i8257_dma_read_memory;
610     idc->write_memory = i8257_dma_write_memory;
611     idc->hold_DREQ = i8257_dma_hold_DREQ;
612     idc->release_DREQ = i8257_dma_release_DREQ;
613     idc->schedule = i8257_dma_schedule;
614     idc->register_channel = i8257_dma_register_channel;
615     /* Reason: needs to be wired up by isa_bus_dma() to work */
616     dc->user_creatable = false;
617 }
618 
619 static const TypeInfo i8257_info = {
620     .name = TYPE_I8257,
621     .parent = TYPE_ISA_DEVICE,
622     .instance_size = sizeof(I8257State),
623     .class_init = i8257_class_init,
624     .interfaces = (InterfaceInfo[]) {
625         { TYPE_ISADMA },
626         { }
627     }
628 };
629 
630 static void i8257_register_types(void)
631 {
632     type_register_static(&i8257_info);
633 }
634 
635 type_init(i8257_register_types)
636 
637 void i8257_dma_init(ISABus *bus, bool high_page_enable)
638 {
639     ISADevice *isa1, *isa2;
640     DeviceState *d;
641 
642     isa1 = isa_new(TYPE_I8257);
643     d = DEVICE(isa1);
644     qdev_prop_set_int32(d, "base", 0x00);
645     qdev_prop_set_int32(d, "page-base", 0x80);
646     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
647     qdev_prop_set_int32(d, "dshift", 0);
648     isa_realize_and_unref(isa1, bus, &error_fatal);
649 
650     isa2 = isa_new(TYPE_I8257);
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