xref: /openbmc/qemu/hw/dma/i8257.c (revision 63e6b5645021bb2b545a39f2896a42da5c300d9c)
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(ISABus *bus, bool high_page_enable)
636  {
637      ISADevice *isa1, *isa2;
638      DeviceState *d;
639  
640      isa1 = isa_new(TYPE_I8257);
641      d = DEVICE(isa1);
642      qdev_prop_set_int32(d, "base", 0x00);
643      qdev_prop_set_int32(d, "page-base", 0x80);
644      qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
645      qdev_prop_set_int32(d, "dshift", 0);
646      isa_realize_and_unref(isa1, bus, &error_fatal);
647  
648      isa2 = isa_new(TYPE_I8257);
649      d = DEVICE(isa2);
650      qdev_prop_set_int32(d, "base", 0xc0);
651      qdev_prop_set_int32(d, "page-base", 0x88);
652      qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
653      qdev_prop_set_int32(d, "dshift", 1);
654      isa_realize_and_unref(isa2, bus, &error_fatal);
655  
656      isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
657  }
658