xref: /openbmc/qemu/hw/dma/i8257.c (revision 6a02465f)
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 
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 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 
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 
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 
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 
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 
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 
396 static bool i8257_is_verify_transfer(I8257Regs *r)
397 {
398     return (r->mode & 0x0c) == 0;
399 }
400 
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 
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  */
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 
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 
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 
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 
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 
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 
628 static void i8257_register_types(void)
629 {
630     type_register_static(&i8257_info);
631 }
632 
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