xref: /openbmc/qemu/hw/dma/i8257.c (revision 87c9b5e0)
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/isa/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 }
346 
347 static void i8257_dma_run(void *opaque)
348 {
349     I8257State *d = opaque;
350     int ichan;
351     int rearm = 0;
352 
353     if (d->running) {
354         rearm = 1;
355         goto out;
356     } else {
357         d->running = 1;
358     }
359 
360     for (ichan = 0; ichan < 4; ichan++) {
361         int mask;
362 
363         mask = 1 << ichan;
364 
365         if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
366             i8257_channel_run(d, ichan);
367             rearm = 1;
368         }
369     }
370 
371     d->running = 0;
372 out:
373     if (rearm) {
374         qemu_bh_schedule_idle(d->dma_bh);
375         d->dma_bh_scheduled = true;
376     }
377 }
378 
379 static void i8257_dma_register_channel(IsaDma *obj, int nchan,
380                                        DMA_transfer_handler transfer_handler,
381                                        void *opaque)
382 {
383     I8257State *d = I8257(obj);
384     I8257Regs *r;
385     int ichan;
386 
387     ichan = nchan & 3;
388 
389     r = d->regs + ichan;
390     r->transfer_handler = transfer_handler;
391     r->opaque = opaque;
392 }
393 
394 static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
395                                  int len)
396 {
397     I8257State *d = I8257(obj);
398     I8257Regs *r = &d->regs[nchan & 3];
399     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
400 
401     if (r->mode & 0x20) {
402         int i;
403         uint8_t *p = buf;
404 
405         cpu_physical_memory_read (addr - pos - len, buf, len);
406         /* What about 16bit transfers? */
407         for (i = 0; i < len >> 1; i++) {
408             uint8_t b = p[len - i - 1];
409             p[i] = b;
410         }
411     }
412     else
413         cpu_physical_memory_read (addr + pos, buf, len);
414 
415     return len;
416 }
417 
418 static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
419                                  int len)
420 {
421     I8257State *s = I8257(obj);
422     I8257Regs *r = &s->regs[nchan & 3];
423     hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
424 
425     if (r->mode & 0x20) {
426         int i;
427         uint8_t *p = buf;
428 
429         cpu_physical_memory_write (addr - pos - len, buf, len);
430         /* What about 16bit transfers? */
431         for (i = 0; i < len; i++) {
432             uint8_t b = p[len - i - 1];
433             p[i] = b;
434         }
435     }
436     else
437         cpu_physical_memory_write (addr + pos, buf, len);
438 
439     return len;
440 }
441 
442 /* request the emulator to transfer a new DMA memory block ASAP (even
443  * if the idle bottom half would not have exited the iothread yet).
444  */
445 static void i8257_dma_schedule(IsaDma *obj)
446 {
447     I8257State *d = I8257(obj);
448     if (d->dma_bh_scheduled) {
449         qemu_notify_event();
450     }
451 }
452 
453 static void i8257_reset(DeviceState *dev)
454 {
455     I8257State *d = I8257(dev);
456     i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
457 }
458 
459 static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
460                                int dma_len)
461 {
462     trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
463     return dma_pos;
464 }
465 
466 
467 static const MemoryRegionOps channel_io_ops = {
468     .read = i8257_read_chan,
469     .write = i8257_write_chan,
470     .endianness = DEVICE_NATIVE_ENDIAN,
471     .impl = {
472         .min_access_size = 1,
473         .max_access_size = 1,
474     },
475 };
476 
477 /* IOport from page_base */
478 static const MemoryRegionPortio page_portio_list[] = {
479     { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
480     { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
481     PORTIO_END_OF_LIST(),
482 };
483 
484 /* IOport from pageh_base */
485 static const MemoryRegionPortio pageh_portio_list[] = {
486     { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
487     { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
488     PORTIO_END_OF_LIST(),
489 };
490 
491 static const MemoryRegionOps cont_io_ops = {
492     .read = i8257_read_cont,
493     .write = i8257_write_cont,
494     .endianness = DEVICE_NATIVE_ENDIAN,
495     .impl = {
496         .min_access_size = 1,
497         .max_access_size = 1,
498     },
499 };
500 
501 static const VMStateDescription vmstate_i8257_regs = {
502     .name = "dma_regs",
503     .version_id = 1,
504     .minimum_version_id = 1,
505     .fields = (VMStateField[]) {
506         VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
507         VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
508         VMSTATE_UINT8(mode, I8257Regs),
509         VMSTATE_UINT8(page, I8257Regs),
510         VMSTATE_UINT8(pageh, I8257Regs),
511         VMSTATE_UINT8(dack, I8257Regs),
512         VMSTATE_UINT8(eop, I8257Regs),
513         VMSTATE_END_OF_LIST()
514     }
515 };
516 
517 static int i8257_post_load(void *opaque, int version_id)
518 {
519     I8257State *d = opaque;
520     i8257_dma_run(d);
521 
522     return 0;
523 }
524 
525 static const VMStateDescription vmstate_i8257 = {
526     .name = "dma",
527     .version_id = 1,
528     .minimum_version_id = 1,
529     .post_load = i8257_post_load,
530     .fields = (VMStateField[]) {
531         VMSTATE_UINT8(command, I8257State),
532         VMSTATE_UINT8(mask, I8257State),
533         VMSTATE_UINT8(flip_flop, I8257State),
534         VMSTATE_INT32(dshift, I8257State),
535         VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
536                              I8257Regs),
537         VMSTATE_END_OF_LIST()
538     }
539 };
540 
541 static void i8257_realize(DeviceState *dev, Error **errp)
542 {
543     ISADevice *isa = ISA_DEVICE(dev);
544     I8257State *d = I8257(dev);
545     int i;
546 
547     memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d,
548                           "dma-chan", 8 << d->dshift);
549     memory_region_add_subregion(isa_address_space_io(isa),
550                                 d->base, &d->channel_io);
551 
552     isa_register_portio_list(isa, d->page_base, page_portio_list, d,
553                              "dma-page");
554     if (d->pageh_base >= 0) {
555         isa_register_portio_list(isa, d->pageh_base, pageh_portio_list, d,
556                                  "dma-pageh");
557     }
558 
559     memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
560                           "dma-cont", 8 << d->dshift);
561     memory_region_add_subregion(isa_address_space_io(isa),
562                                 d->base + (8 << d->dshift), &d->cont_io);
563 
564     for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
565         d->regs[i].transfer_handler = i8257_phony_handler;
566     }
567 
568     d->dma_bh = qemu_bh_new(i8257_dma_run, d);
569 }
570 
571 static Property i8257_properties[] = {
572     DEFINE_PROP_INT32("base", I8257State, base, 0x00),
573     DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
574     DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
575     DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
576     DEFINE_PROP_END_OF_LIST()
577 };
578 
579 static void i8257_class_init(ObjectClass *klass, void *data)
580 {
581     DeviceClass *dc = DEVICE_CLASS(klass);
582     IsaDmaClass *idc = ISADMA_CLASS(klass);
583 
584     dc->realize = i8257_realize;
585     dc->reset = i8257_reset;
586     dc->vmsd = &vmstate_i8257;
587     dc->props = i8257_properties;
588 
589     idc->get_transfer_mode = i8257_dma_get_transfer_mode;
590     idc->has_autoinitialization = i8257_dma_has_autoinitialization;
591     idc->read_memory = i8257_dma_read_memory;
592     idc->write_memory = i8257_dma_write_memory;
593     idc->hold_DREQ = i8257_dma_hold_DREQ;
594     idc->release_DREQ = i8257_dma_release_DREQ;
595     idc->schedule = i8257_dma_schedule;
596     idc->register_channel = i8257_dma_register_channel;
597 }
598 
599 static const TypeInfo i8257_info = {
600     .name = TYPE_I8257,
601     .parent = TYPE_ISA_DEVICE,
602     .instance_size = sizeof(I8257State),
603     .class_init = i8257_class_init,
604     .interfaces = (InterfaceInfo[]) {
605         { TYPE_ISADMA },
606         { }
607     }
608 };
609 
610 static void i8257_register_types(void)
611 {
612     type_register_static(&i8257_info);
613 }
614 
615 type_init(i8257_register_types)
616 
617 void DMA_init(ISABus *bus, int high_page_enable)
618 {
619     ISADevice *isa1, *isa2;
620     DeviceState *d;
621 
622     isa1 = isa_create(bus, TYPE_I8257);
623     d = DEVICE(isa1);
624     qdev_prop_set_int32(d, "base", 0x00);
625     qdev_prop_set_int32(d, "page-base", 0x80);
626     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
627     qdev_prop_set_int32(d, "dshift", 0);
628     qdev_init_nofail(d);
629 
630     isa2 = isa_create(bus, TYPE_I8257);
631     d = DEVICE(isa2);
632     qdev_prop_set_int32(d, "base", 0xc0);
633     qdev_prop_set_int32(d, "page-base", 0x88);
634     qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
635     qdev_prop_set_int32(d, "dshift", 1);
636     qdev_init_nofail(d);
637 
638     isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
639 }
640