xref: /openbmc/qemu/hw/dma/i8257.c (revision 310b3fe9e50a59f7911f8930bc523a7a0b84bb89)
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 "qemu/log.h"
30  #include "trace.h"
31  
32  #define I8257(obj) \
33      OBJECT_CHECK(I8257State, (obj), TYPE_I8257)
34  
35  /* #define DEBUG_DMA */
36  
37  #define dolog(...) fprintf (stderr, "dma: " __VA_ARGS__)
38  #ifdef DEBUG_DMA
39  #define linfo(...) fprintf (stderr, "dma: " __VA_ARGS__)
40  #define ldebug(...) fprintf (stderr, "dma: " __VA_ARGS__)
41  #else
42  #define linfo(...)
43  #define ldebug(...)
44  #endif
45  
46  #define ADDR 0
47  #define COUNT 1
48  
49  enum {
50      CMD_MEMORY_TO_MEMORY = 0x01,
51      CMD_FIXED_ADDRESS    = 0x02,
52      CMD_BLOCK_CONTROLLER = 0x04,
53      CMD_COMPRESSED_TIME  = 0x08,
54      CMD_CYCLIC_PRIORITY  = 0x10,
55      CMD_EXTENDED_WRITE   = 0x20,
56      CMD_LOW_DREQ         = 0x40,
57      CMD_LOW_DACK         = 0x80,
58      CMD_NOT_SUPPORTED    = CMD_MEMORY_TO_MEMORY | CMD_FIXED_ADDRESS
59      | CMD_COMPRESSED_TIME | CMD_CYCLIC_PRIORITY | CMD_EXTENDED_WRITE
60      | CMD_LOW_DREQ | CMD_LOW_DACK
61  
62  };
63  
64  static void i8257_dma_run(void *opaque);
65  
66  static const int channels[8] = {-1, 2, 3, 1, -1, -1, -1, 0};
67  
68  static void i8257_write_page(void *opaque, uint32_t nport, uint32_t data)
69  {
70      I8257State *d = opaque;
71      int ichan;
72  
73      ichan = channels[nport & 7];
74      if (-1 == ichan) {
75          dolog ("invalid channel %#x %#x\n", nport, data);
76          return;
77      }
78      d->regs[ichan].page = data;
79  }
80  
81  static void i8257_write_pageh(void *opaque, uint32_t nport, uint32_t data)
82  {
83      I8257State *d = opaque;
84      int ichan;
85  
86      ichan = channels[nport & 7];
87      if (-1 == ichan) {
88          dolog ("invalid channel %#x %#x\n", nport, data);
89          return;
90      }
91      d->regs[ichan].pageh = data;
92  }
93  
94  static uint32_t i8257_read_page(void *opaque, uint32_t nport)
95  {
96      I8257State *d = opaque;
97      int ichan;
98  
99      ichan = channels[nport & 7];
100      if (-1 == ichan) {
101          dolog ("invalid channel read %#x\n", nport);
102          return 0;
103      }
104      return d->regs[ichan].page;
105  }
106  
107  static uint32_t i8257_read_pageh(void *opaque, uint32_t nport)
108  {
109      I8257State *d = opaque;
110      int ichan;
111  
112      ichan = channels[nport & 7];
113      if (-1 == ichan) {
114          dolog ("invalid channel read %#x\n", nport);
115          return 0;
116      }
117      return d->regs[ichan].pageh;
118  }
119  
120  static inline void i8257_init_chan(I8257State *d, int ichan)
121  {
122      I8257Regs *r;
123  
124      r = d->regs + ichan;
125      r->now[ADDR] = r->base[ADDR] << d->dshift;
126      r->now[COUNT] = 0;
127  }
128  
129  static inline int i8257_getff(I8257State *d)
130  {
131      int ff;
132  
133      ff = d->flip_flop;
134      d->flip_flop = !ff;
135      return ff;
136  }
137  
138  static uint64_t i8257_read_chan(void *opaque, hwaddr nport, unsigned size)
139  {
140      I8257State *d = opaque;
141      int ichan, nreg, iport, ff, val, dir;
142      I8257Regs *r;
143  
144      iport = (nport >> d->dshift) & 0x0f;
145      ichan = iport >> 1;
146      nreg = iport & 1;
147      r = d->regs + ichan;
148  
149      dir = ((r->mode >> 5) & 1) ? -1 : 1;
150      ff = i8257_getff(d);
151      if (nreg)
152          val = (r->base[COUNT] << d->dshift) - r->now[COUNT];
153      else
154          val = r->now[ADDR] + r->now[COUNT] * dir;
155  
156      ldebug ("read_chan %#x -> %d\n", iport, val);
157      return (val >> (d->dshift + (ff << 3))) & 0xff;
158  }
159  
160  static void i8257_write_chan(void *opaque, hwaddr nport, uint64_t data,
161                               unsigned int size)
162  {
163      I8257State *d = opaque;
164      int iport, ichan, nreg;
165      I8257Regs *r;
166  
167      iport = (nport >> d->dshift) & 0x0f;
168      ichan = iport >> 1;
169      nreg = iport & 1;
170      r = d->regs + ichan;
171      if (i8257_getff(d)) {
172          r->base[nreg] = (r->base[nreg] & 0xff) | ((data << 8) & 0xff00);
173          i8257_init_chan(d, ichan);
174      } else {
175          r->base[nreg] = (r->base[nreg] & 0xff00) | (data & 0xff);
176      }
177  }
178  
179  static void i8257_write_cont(void *opaque, hwaddr nport, uint64_t data,
180                               unsigned int size)
181  {
182      I8257State *d = opaque;
183      int iport, ichan = 0;
184  
185      iport = (nport >> d->dshift) & 0x0f;
186      switch (iport) {
187      case 0x00:                  /* command */
188          if ((data != 0) && (data & CMD_NOT_SUPPORTED)) {
189              qemu_log_mask(LOG_UNIMP, "%s: cmd 0x%02"PRIx64" not supported\n",
190                            __func__, data);
191              return;
192          }
193          d->command = data;
194          break;
195  
196      case 0x01:
197          ichan = data & 3;
198          if (data & 4) {
199              d->status |= 1 << (ichan + 4);
200          }
201          else {
202              d->status &= ~(1 << (ichan + 4));
203          }
204          d->status &= ~(1 << ichan);
205          i8257_dma_run(d);
206          break;
207  
208      case 0x02:                  /* single mask */
209          if (data & 4)
210              d->mask |= 1 << (data & 3);
211          else
212              d->mask &= ~(1 << (data & 3));
213          i8257_dma_run(d);
214          break;
215  
216      case 0x03:                  /* mode */
217          {
218              ichan = data & 3;
219  #ifdef DEBUG_DMA
220              {
221                  int op, ai, dir, opmode;
222                  op = (data >> 2) & 3;
223                  ai = (data >> 4) & 1;
224                  dir = (data >> 5) & 1;
225                  opmode = (data >> 6) & 3;
226  
227                  linfo ("ichan %d, op %d, ai %d, dir %d, opmode %d\n",
228                         ichan, op, ai, dir, opmode);
229              }
230  #endif
231              d->regs[ichan].mode = data;
232              break;
233          }
234  
235      case 0x04:                  /* clear flip flop */
236          d->flip_flop = 0;
237          break;
238  
239      case 0x05:                  /* reset */
240          d->flip_flop = 0;
241          d->mask = ~0;
242          d->status = 0;
243          d->command = 0;
244          break;
245  
246      case 0x06:                  /* clear mask for all channels */
247          d->mask = 0;
248          i8257_dma_run(d);
249          break;
250  
251      case 0x07:                  /* write mask for all channels */
252          d->mask = data;
253          i8257_dma_run(d);
254          break;
255  
256      default:
257          dolog ("unknown iport %#x\n", iport);
258          break;
259      }
260  
261  #ifdef DEBUG_DMA
262      if (0xc != iport) {
263          linfo ("write_cont: nport %#06x, ichan % 2d, val %#06x\n",
264                 nport, ichan, data);
265      }
266  #endif
267  }
268  
269  static uint64_t i8257_read_cont(void *opaque, hwaddr nport, unsigned size)
270  {
271      I8257State *d = opaque;
272      int iport, val;
273  
274      iport = (nport >> d->dshift) & 0x0f;
275      switch (iport) {
276      case 0x00:                  /* status */
277          val = d->status;
278          d->status &= 0xf0;
279          break;
280      case 0x01:                  /* mask */
281          val = d->mask;
282          break;
283      default:
284          val = 0;
285          break;
286      }
287  
288      ldebug ("read_cont: nport %#06x, iport %#04x val %#x\n", nport, iport, val);
289      return val;
290  }
291  
292  static IsaDmaTransferMode i8257_dma_get_transfer_mode(IsaDma *obj, int nchan)
293  {
294      I8257State *d = I8257(obj);
295      return (d->regs[nchan & 3].mode >> 2) & 3;
296  }
297  
298  static bool i8257_dma_has_autoinitialization(IsaDma *obj, int nchan)
299  {
300      I8257State *d = I8257(obj);
301      return (d->regs[nchan & 3].mode >> 4) & 1;
302  }
303  
304  static void i8257_dma_hold_DREQ(IsaDma *obj, int nchan)
305  {
306      I8257State *d = I8257(obj);
307      int ichan;
308  
309      ichan = nchan & 3;
310      d->status |= 1 << (ichan + 4);
311      i8257_dma_run(d);
312  }
313  
314  static void i8257_dma_release_DREQ(IsaDma *obj, int nchan)
315  {
316      I8257State *d = I8257(obj);
317      int ichan;
318  
319      ichan = nchan & 3;
320      d->status &= ~(1 << (ichan + 4));
321      i8257_dma_run(d);
322  }
323  
324  static void i8257_channel_run(I8257State *d, int ichan)
325  {
326      int ncont = d->dshift;
327      int n;
328      I8257Regs *r = &d->regs[ichan];
329  #ifdef DEBUG_DMA
330      int dir, opmode;
331  
332      dir = (r->mode >> 5) & 1;
333      opmode = (r->mode >> 6) & 3;
334  
335      if (dir) {
336          dolog ("DMA in address decrement mode\n");
337      }
338      if (opmode != 1) {
339          dolog ("DMA not in single mode select %#x\n", opmode);
340      }
341  #endif
342  
343      n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
344                               r->now[COUNT], (r->base[COUNT] + 1) << ncont);
345      r->now[COUNT] = n;
346      ldebug ("dma_pos %d size %d\n", n, (r->base[COUNT] + 1) << ncont);
347      if (n == (r->base[COUNT] + 1) << ncont) {
348          ldebug("transfer done\n");
349          d->status |= (1 << ichan);
350      }
351  }
352  
353  static void i8257_dma_run(void *opaque)
354  {
355      I8257State *d = opaque;
356      int ichan;
357      int rearm = 0;
358  
359      if (d->running) {
360          rearm = 1;
361          goto out;
362      } else {
363          d->running = 1;
364      }
365  
366      for (ichan = 0; ichan < 4; ichan++) {
367          int mask;
368  
369          mask = 1 << ichan;
370  
371          if ((0 == (d->mask & mask)) && (0 != (d->status & (mask << 4)))) {
372              i8257_channel_run(d, ichan);
373              rearm = 1;
374          }
375      }
376  
377      d->running = 0;
378  out:
379      if (rearm) {
380          qemu_bh_schedule_idle(d->dma_bh);
381          d->dma_bh_scheduled = true;
382      }
383  }
384  
385  static void i8257_dma_register_channel(IsaDma *obj, int nchan,
386                                         IsaDmaTransferHandler transfer_handler,
387                                         void *opaque)
388  {
389      I8257State *d = I8257(obj);
390      I8257Regs *r;
391      int ichan;
392  
393      ichan = nchan & 3;
394  
395      r = d->regs + ichan;
396      r->transfer_handler = transfer_handler;
397      r->opaque = opaque;
398  }
399  
400  static int i8257_dma_read_memory(IsaDma *obj, int nchan, void *buf, int pos,
401                                   int len)
402  {
403      I8257State *d = I8257(obj);
404      I8257Regs *r = &d->regs[nchan & 3];
405      hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
406  
407      if (r->mode & 0x20) {
408          int i;
409          uint8_t *p = buf;
410  
411          cpu_physical_memory_read (addr - pos - len, buf, len);
412          /* What about 16bit transfers? */
413          for (i = 0; i < len >> 1; i++) {
414              uint8_t b = p[len - i - 1];
415              p[i] = b;
416          }
417      }
418      else
419          cpu_physical_memory_read (addr + pos, buf, len);
420  
421      return len;
422  }
423  
424  static int i8257_dma_write_memory(IsaDma *obj, int nchan, void *buf, int pos,
425                                   int len)
426  {
427      I8257State *s = I8257(obj);
428      I8257Regs *r = &s->regs[nchan & 3];
429      hwaddr addr = ((r->pageh & 0x7f) << 24) | (r->page << 16) | r->now[ADDR];
430  
431      if (r->mode & 0x20) {
432          int i;
433          uint8_t *p = buf;
434  
435          cpu_physical_memory_write (addr - pos - len, buf, len);
436          /* What about 16bit transfers? */
437          for (i = 0; i < len; i++) {
438              uint8_t b = p[len - i - 1];
439              p[i] = b;
440          }
441      }
442      else
443          cpu_physical_memory_write (addr + pos, buf, len);
444  
445      return len;
446  }
447  
448  /* request the emulator to transfer a new DMA memory block ASAP (even
449   * if the idle bottom half would not have exited the iothread yet).
450   */
451  static void i8257_dma_schedule(IsaDma *obj)
452  {
453      I8257State *d = I8257(obj);
454      if (d->dma_bh_scheduled) {
455          qemu_notify_event();
456      }
457  }
458  
459  static void i8257_reset(DeviceState *dev)
460  {
461      I8257State *d = I8257(dev);
462      i8257_write_cont(d, (0x05 << d->dshift), 0, 1);
463  }
464  
465  static int i8257_phony_handler(void *opaque, int nchan, int dma_pos,
466                                 int dma_len)
467  {
468      trace_i8257_unregistered_dma(nchan, dma_pos, dma_len);
469      return dma_pos;
470  }
471  
472  
473  static const MemoryRegionOps channel_io_ops = {
474      .read = i8257_read_chan,
475      .write = i8257_write_chan,
476      .endianness = DEVICE_NATIVE_ENDIAN,
477      .impl = {
478          .min_access_size = 1,
479          .max_access_size = 1,
480      },
481  };
482  
483  /* IOport from page_base */
484  static const MemoryRegionPortio page_portio_list[] = {
485      { 0x01, 3, 1, .write = i8257_write_page, .read = i8257_read_page, },
486      { 0x07, 1, 1, .write = i8257_write_page, .read = i8257_read_page, },
487      PORTIO_END_OF_LIST(),
488  };
489  
490  /* IOport from pageh_base */
491  static const MemoryRegionPortio pageh_portio_list[] = {
492      { 0x01, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
493      { 0x07, 3, 1, .write = i8257_write_pageh, .read = i8257_read_pageh, },
494      PORTIO_END_OF_LIST(),
495  };
496  
497  static const MemoryRegionOps cont_io_ops = {
498      .read = i8257_read_cont,
499      .write = i8257_write_cont,
500      .endianness = DEVICE_NATIVE_ENDIAN,
501      .impl = {
502          .min_access_size = 1,
503          .max_access_size = 1,
504      },
505  };
506  
507  static const VMStateDescription vmstate_i8257_regs = {
508      .name = "dma_regs",
509      .version_id = 1,
510      .minimum_version_id = 1,
511      .fields = (VMStateField[]) {
512          VMSTATE_INT32_ARRAY(now, I8257Regs, 2),
513          VMSTATE_UINT16_ARRAY(base, I8257Regs, 2),
514          VMSTATE_UINT8(mode, I8257Regs),
515          VMSTATE_UINT8(page, I8257Regs),
516          VMSTATE_UINT8(pageh, I8257Regs),
517          VMSTATE_UINT8(dack, I8257Regs),
518          VMSTATE_UINT8(eop, I8257Regs),
519          VMSTATE_END_OF_LIST()
520      }
521  };
522  
523  static int i8257_post_load(void *opaque, int version_id)
524  {
525      I8257State *d = opaque;
526      i8257_dma_run(d);
527  
528      return 0;
529  }
530  
531  static const VMStateDescription vmstate_i8257 = {
532      .name = "dma",
533      .version_id = 1,
534      .minimum_version_id = 1,
535      .post_load = i8257_post_load,
536      .fields = (VMStateField[]) {
537          VMSTATE_UINT8(command, I8257State),
538          VMSTATE_UINT8(mask, I8257State),
539          VMSTATE_UINT8(flip_flop, I8257State),
540          VMSTATE_INT32(dshift, I8257State),
541          VMSTATE_STRUCT_ARRAY(regs, I8257State, 4, 1, vmstate_i8257_regs,
542                               I8257Regs),
543          VMSTATE_END_OF_LIST()
544      }
545  };
546  
547  static void i8257_realize(DeviceState *dev, Error **errp)
548  {
549      ISADevice *isa = ISA_DEVICE(dev);
550      I8257State *d = I8257(dev);
551      int i;
552  
553      memory_region_init_io(&d->channel_io, NULL, &channel_io_ops, d,
554                            "dma-chan", 8 << d->dshift);
555      memory_region_add_subregion(isa_address_space_io(isa),
556                                  d->base, &d->channel_io);
557  
558      isa_register_portio_list(isa, &d->portio_page,
559                               d->page_base, page_portio_list, d,
560                               "dma-page");
561      if (d->pageh_base >= 0) {
562          isa_register_portio_list(isa, &d->portio_pageh,
563                                   d->pageh_base, pageh_portio_list, d,
564                                   "dma-pageh");
565      }
566  
567      memory_region_init_io(&d->cont_io, OBJECT(isa), &cont_io_ops, d,
568                            "dma-cont", 8 << d->dshift);
569      memory_region_add_subregion(isa_address_space_io(isa),
570                                  d->base + (8 << d->dshift), &d->cont_io);
571  
572      for (i = 0; i < ARRAY_SIZE(d->regs); ++i) {
573          d->regs[i].transfer_handler = i8257_phony_handler;
574      }
575  
576      d->dma_bh = qemu_bh_new(i8257_dma_run, d);
577  }
578  
579  static Property i8257_properties[] = {
580      DEFINE_PROP_INT32("base", I8257State, base, 0x00),
581      DEFINE_PROP_INT32("page-base", I8257State, page_base, 0x80),
582      DEFINE_PROP_INT32("pageh-base", I8257State, pageh_base, 0x480),
583      DEFINE_PROP_INT32("dshift", I8257State, dshift, 0),
584      DEFINE_PROP_END_OF_LIST()
585  };
586  
587  static void i8257_class_init(ObjectClass *klass, void *data)
588  {
589      DeviceClass *dc = DEVICE_CLASS(klass);
590      IsaDmaClass *idc = ISADMA_CLASS(klass);
591  
592      dc->realize = i8257_realize;
593      dc->reset = i8257_reset;
594      dc->vmsd = &vmstate_i8257;
595      dc->props = i8257_properties;
596  
597      idc->get_transfer_mode = i8257_dma_get_transfer_mode;
598      idc->has_autoinitialization = i8257_dma_has_autoinitialization;
599      idc->read_memory = i8257_dma_read_memory;
600      idc->write_memory = i8257_dma_write_memory;
601      idc->hold_DREQ = i8257_dma_hold_DREQ;
602      idc->release_DREQ = i8257_dma_release_DREQ;
603      idc->schedule = i8257_dma_schedule;
604      idc->register_channel = i8257_dma_register_channel;
605      /* Reason: needs to be wired up by isa_bus_dma() to work */
606      dc->user_creatable = false;
607  }
608  
609  static const TypeInfo i8257_info = {
610      .name = TYPE_I8257,
611      .parent = TYPE_ISA_DEVICE,
612      .instance_size = sizeof(I8257State),
613      .class_init = i8257_class_init,
614      .interfaces = (InterfaceInfo[]) {
615          { TYPE_ISADMA },
616          { }
617      }
618  };
619  
620  static void i8257_register_types(void)
621  {
622      type_register_static(&i8257_info);
623  }
624  
625  type_init(i8257_register_types)
626  
627  void i8257_dma_init(ISABus *bus, bool high_page_enable)
628  {
629      ISADevice *isa1, *isa2;
630      DeviceState *d;
631  
632      isa1 = isa_create(bus, TYPE_I8257);
633      d = DEVICE(isa1);
634      qdev_prop_set_int32(d, "base", 0x00);
635      qdev_prop_set_int32(d, "page-base", 0x80);
636      qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
637      qdev_prop_set_int32(d, "dshift", 0);
638      qdev_init_nofail(d);
639  
640      isa2 = isa_create(bus, TYPE_I8257);
641      d = DEVICE(isa2);
642      qdev_prop_set_int32(d, "base", 0xc0);
643      qdev_prop_set_int32(d, "page-base", 0x88);
644      qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
645      qdev_prop_set_int32(d, "dshift", 1);
646      qdev_init_nofail(d);
647  
648      isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
649  }
650