xref: /openbmc/qemu/hw/dma/etraxfs_dma.c (revision 8acf8650)
1 /*
2  * QEMU ETRAX DMA Controller.
3  *
4  * Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
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/hw.h"
27 #include "hw/irq.h"
28 #include "qemu/main-loop.h"
29 #include "sysemu/runstate.h"
30 #include "exec/address-spaces.h"
31 
32 #include "hw/cris/etraxfs_dma.h"
33 
34 #define D(x)
35 
36 #define RW_DATA           (0x0 / 4)
37 #define RW_SAVED_DATA     (0x58 / 4)
38 #define RW_SAVED_DATA_BUF (0x5c / 4)
39 #define RW_GROUP          (0x60 / 4)
40 #define RW_GROUP_DOWN     (0x7c / 4)
41 #define RW_CMD            (0x80 / 4)
42 #define RW_CFG            (0x84 / 4)
43 #define RW_STAT           (0x88 / 4)
44 #define RW_INTR_MASK      (0x8c / 4)
45 #define RW_ACK_INTR       (0x90 / 4)
46 #define R_INTR            (0x94 / 4)
47 #define R_MASKED_INTR     (0x98 / 4)
48 #define RW_STREAM_CMD     (0x9c / 4)
49 
50 #define DMA_REG_MAX       (0x100 / 4)
51 
52 /* descriptors */
53 
54 // ------------------------------------------------------------ dma_descr_group
55 typedef struct dma_descr_group {
56   uint32_t                      next;
57   unsigned                      eol        : 1;
58   unsigned                      tol        : 1;
59   unsigned                      bol        : 1;
60   unsigned                                 : 1;
61   unsigned                      intr       : 1;
62   unsigned                                 : 2;
63   unsigned                      en         : 1;
64   unsigned                                 : 7;
65   unsigned                      dis        : 1;
66   unsigned                      md         : 16;
67   struct dma_descr_group       *up;
68   union {
69     struct dma_descr_context   *context;
70     struct dma_descr_group     *group;
71   }                             down;
72 } dma_descr_group;
73 
74 // ---------------------------------------------------------- dma_descr_context
75 typedef struct dma_descr_context {
76   uint32_t                      next;
77   unsigned                      eol        : 1;
78   unsigned                                 : 3;
79   unsigned                      intr       : 1;
80   unsigned                                 : 1;
81   unsigned                      store_mode : 1;
82   unsigned                      en         : 1;
83   unsigned                                 : 7;
84   unsigned                      dis        : 1;
85   unsigned                      md0        : 16;
86   unsigned                      md1;
87   unsigned                      md2;
88   unsigned                      md3;
89   unsigned                      md4;
90   uint32_t                      saved_data;
91   uint32_t                      saved_data_buf;
92 } dma_descr_context;
93 
94 // ------------------------------------------------------------- dma_descr_data
95 typedef struct dma_descr_data {
96   uint32_t                      next;
97   uint32_t                      buf;
98   unsigned                      eol        : 1;
99   unsigned                                 : 2;
100   unsigned                      out_eop    : 1;
101   unsigned                      intr       : 1;
102   unsigned                      wait       : 1;
103   unsigned                                 : 2;
104   unsigned                                 : 3;
105   unsigned                      in_eop     : 1;
106   unsigned                                 : 4;
107   unsigned                      md         : 16;
108   uint32_t                      after;
109 } dma_descr_data;
110 
111 /* Constants */
112 enum {
113   regk_dma_ack_pkt                         = 0x00000100,
114   regk_dma_anytime                         = 0x00000001,
115   regk_dma_array                           = 0x00000008,
116   regk_dma_burst                           = 0x00000020,
117   regk_dma_client                          = 0x00000002,
118   regk_dma_copy_next                       = 0x00000010,
119   regk_dma_copy_up                         = 0x00000020,
120   regk_dma_data_at_eol                     = 0x00000001,
121   regk_dma_dis_c                           = 0x00000010,
122   regk_dma_dis_g                           = 0x00000020,
123   regk_dma_idle                            = 0x00000001,
124   regk_dma_intern                          = 0x00000004,
125   regk_dma_load_c                          = 0x00000200,
126   regk_dma_load_c_n                        = 0x00000280,
127   regk_dma_load_c_next                     = 0x00000240,
128   regk_dma_load_d                          = 0x00000140,
129   regk_dma_load_g                          = 0x00000300,
130   regk_dma_load_g_down                     = 0x000003c0,
131   regk_dma_load_g_next                     = 0x00000340,
132   regk_dma_load_g_up                       = 0x00000380,
133   regk_dma_next_en                         = 0x00000010,
134   regk_dma_next_pkt                        = 0x00000010,
135   regk_dma_no                              = 0x00000000,
136   regk_dma_only_at_wait                    = 0x00000000,
137   regk_dma_restore                         = 0x00000020,
138   regk_dma_rst                             = 0x00000001,
139   regk_dma_running                         = 0x00000004,
140   regk_dma_rw_cfg_default                  = 0x00000000,
141   regk_dma_rw_cmd_default                  = 0x00000000,
142   regk_dma_rw_intr_mask_default            = 0x00000000,
143   regk_dma_rw_stat_default                 = 0x00000101,
144   regk_dma_rw_stream_cmd_default           = 0x00000000,
145   regk_dma_save_down                       = 0x00000020,
146   regk_dma_save_up                         = 0x00000020,
147   regk_dma_set_reg                         = 0x00000050,
148   regk_dma_set_w_size1                     = 0x00000190,
149   regk_dma_set_w_size2                     = 0x000001a0,
150   regk_dma_set_w_size4                     = 0x000001c0,
151   regk_dma_stopped                         = 0x00000002,
152   regk_dma_store_c                         = 0x00000002,
153   regk_dma_store_descr                     = 0x00000000,
154   regk_dma_store_g                         = 0x00000004,
155   regk_dma_store_md                        = 0x00000001,
156   regk_dma_sw                              = 0x00000008,
157   regk_dma_update_down                     = 0x00000020,
158   regk_dma_yes                             = 0x00000001
159 };
160 
161 enum dma_ch_state
162 {
163     RST = 1,
164     STOPPED = 2,
165     RUNNING = 4
166 };
167 
168 struct fs_dma_channel
169 {
170     qemu_irq irq;
171     struct etraxfs_dma_client *client;
172 
173     /* Internal status.  */
174     int stream_cmd_src;
175     enum dma_ch_state state;
176 
177     unsigned int input : 1;
178     unsigned int eol : 1;
179 
180     struct dma_descr_group current_g;
181     struct dma_descr_context current_c;
182     struct dma_descr_data current_d;
183 
184     /* Control registers.  */
185     uint32_t regs[DMA_REG_MAX];
186 };
187 
188 struct fs_dma_ctrl
189 {
190     MemoryRegion mmio;
191     int nr_channels;
192     struct fs_dma_channel *channels;
193 
194     QEMUBH *bh;
195 };
196 
197 static void DMA_run(void *opaque);
198 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
199 
200 static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
201 {
202     return ctrl->channels[c].regs[reg];
203 }
204 
205 static inline int channel_stopped(struct fs_dma_ctrl *ctrl, int c)
206 {
207     return channel_reg(ctrl, c, RW_CFG) & 2;
208 }
209 
210 static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
211 {
212     return (channel_reg(ctrl, c, RW_CFG) & 1)
213             && ctrl->channels[c].client;
214 }
215 
216 static inline int fs_channel(hwaddr addr)
217 {
218     /* Every channel has a 0x2000 ctrl register map.  */
219     return addr >> 13;
220 }
221 
222 #ifdef USE_THIS_DEAD_CODE
223 static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
224 {
225     hwaddr addr = channel_reg(ctrl, c, RW_GROUP);
226 
227     /* Load and decode. FIXME: handle endianness.  */
228     cpu_physical_memory_read(addr, &ctrl->channels[c].current_g,
229                              sizeof(ctrl->channels[c].current_g));
230 }
231 
232 static void dump_c(int ch, struct dma_descr_context *c)
233 {
234     printf("%s ch=%d\n", __func__, ch);
235     printf("next=%x\n", c->next);
236     printf("saved_data=%x\n", c->saved_data);
237     printf("saved_data_buf=%x\n", c->saved_data_buf);
238     printf("eol=%x\n", (uint32_t) c->eol);
239 }
240 
241 static void dump_d(int ch, struct dma_descr_data *d)
242 {
243     printf("%s ch=%d\n", __func__, ch);
244     printf("next=%x\n", d->next);
245     printf("buf=%x\n", d->buf);
246     printf("after=%x\n", d->after);
247     printf("intr=%x\n", (uint32_t) d->intr);
248     printf("out_eop=%x\n", (uint32_t) d->out_eop);
249     printf("in_eop=%x\n", (uint32_t) d->in_eop);
250     printf("eol=%x\n", (uint32_t) d->eol);
251 }
252 #endif
253 
254 static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
255 {
256     hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
257 
258     /* Load and decode. FIXME: handle endianness.  */
259     cpu_physical_memory_read(addr, &ctrl->channels[c].current_c,
260                              sizeof(ctrl->channels[c].current_c));
261 
262     D(dump_c(c, &ctrl->channels[c].current_c));
263     /* I guess this should update the current pos.  */
264     ctrl->channels[c].regs[RW_SAVED_DATA] =
265         (uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data;
266     ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
267         (uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data_buf;
268 }
269 
270 static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
271 {
272     hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
273 
274     /* Load and decode. FIXME: handle endianness.  */
275     D(printf("%s ch=%d addr=" HWADDR_FMT_plx "\n", __func__, c, addr));
276     cpu_physical_memory_read(addr, &ctrl->channels[c].current_d,
277                              sizeof(ctrl->channels[c].current_d));
278 
279     D(dump_d(c, &ctrl->channels[c].current_d));
280     ctrl->channels[c].regs[RW_DATA] = addr;
281 }
282 
283 static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
284 {
285     hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
286 
287     /* Encode and store. FIXME: handle endianness.  */
288     D(printf("%s ch=%d addr=" HWADDR_FMT_plx "\n", __func__, c, addr));
289     D(dump_d(c, &ctrl->channels[c].current_d));
290     cpu_physical_memory_write(addr, &ctrl->channels[c].current_c,
291                               sizeof(ctrl->channels[c].current_c));
292 }
293 
294 static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
295 {
296     hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
297 
298     /* Encode and store. FIXME: handle endianness.  */
299     D(printf("%s ch=%d addr=" HWADDR_FMT_plx "\n", __func__, c, addr));
300     cpu_physical_memory_write(addr, &ctrl->channels[c].current_d,
301                               sizeof(ctrl->channels[c].current_d));
302 }
303 
304 static inline void channel_stop(struct fs_dma_ctrl *ctrl, int c)
305 {
306     /* FIXME:  */
307 }
308 
309 static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
310 {
311     if (ctrl->channels[c].client)
312     {
313         ctrl->channels[c].eol = 0;
314         ctrl->channels[c].state = RUNNING;
315         if (!ctrl->channels[c].input)
316             channel_out_run(ctrl, c);
317     } else
318         printf("WARNING: starting DMA ch %d with no client\n", c);
319 
320     qemu_bh_schedule_idle(ctrl->bh);
321 }
322 
323 static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
324 {
325     if (!channel_en(ctrl, c)
326         || channel_stopped(ctrl, c)
327         || ctrl->channels[c].state != RUNNING
328         /* Only reload the current data descriptor if it has eol set.  */
329         || !ctrl->channels[c].current_d.eol) {
330         D(printf("continue failed ch=%d state=%d stopped=%d en=%d eol=%d\n",
331                  c, ctrl->channels[c].state,
332                  channel_stopped(ctrl, c),
333                  channel_en(ctrl,c),
334                  ctrl->channels[c].eol));
335         D(dump_d(c, &ctrl->channels[c].current_d));
336         return;
337     }
338 
339     /* Reload the current descriptor.  */
340     channel_load_d(ctrl, c);
341 
342     /* If the current descriptor cleared the eol flag and we had already
343        reached eol state, do the continue.  */
344     if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
345         D(printf("continue %d ok %x\n", c,
346                  ctrl->channels[c].current_d.next));
347         ctrl->channels[c].regs[RW_SAVED_DATA] =
348             (uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
349         channel_load_d(ctrl, c);
350         ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
351             (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
352 
353         channel_start(ctrl, c);
354     }
355     ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
356         (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
357 }
358 
359 static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
360 {
361     unsigned int cmd = v & ((1 << 10) - 1);
362 
363     D(printf("%s ch=%d cmd=%x\n",
364              __func__, c, cmd));
365     if (cmd & regk_dma_load_d) {
366         channel_load_d(ctrl, c);
367         if (cmd & regk_dma_burst)
368             channel_start(ctrl, c);
369     }
370 
371     if (cmd & regk_dma_load_c) {
372         channel_load_c(ctrl, c);
373     }
374 }
375 
376 static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
377 {
378     D(printf("%s %d\n", __func__, c));
379     ctrl->channels[c].regs[R_INTR] &=
380         ~(ctrl->channels[c].regs[RW_ACK_INTR]);
381 
382     ctrl->channels[c].regs[R_MASKED_INTR] =
383         ctrl->channels[c].regs[R_INTR]
384         & ctrl->channels[c].regs[RW_INTR_MASK];
385 
386     D(printf("%s: chan=%d masked_intr=%x\n", __func__,
387              c,
388              ctrl->channels[c].regs[R_MASKED_INTR]));
389 
390     qemu_set_irq(ctrl->channels[c].irq,
391                  !!ctrl->channels[c].regs[R_MASKED_INTR]);
392 }
393 
394 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
395 {
396     uint32_t len;
397     uint32_t saved_data_buf;
398     unsigned char buf[2 * 1024];
399 
400     struct dma_context_metadata meta;
401     bool send_context = true;
402 
403     if (ctrl->channels[c].eol)
404         return 0;
405 
406     do {
407         bool out_eop;
408         D(printf("ch=%d buf=%x after=%x\n",
409                  c,
410                  (uint32_t)ctrl->channels[c].current_d.buf,
411                  (uint32_t)ctrl->channels[c].current_d.after));
412 
413         if (send_context) {
414             if (ctrl->channels[c].client->client.metadata_push) {
415                 meta.metadata = ctrl->channels[c].current_d.md;
416                 ctrl->channels[c].client->client.metadata_push(
417                     ctrl->channels[c].client->client.opaque,
418                     &meta);
419             }
420             send_context = false;
421         }
422 
423         channel_load_d(ctrl, c);
424         saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
425         len = (uint32_t)(unsigned long)
426             ctrl->channels[c].current_d.after;
427         len -= saved_data_buf;
428 
429         if (len > sizeof buf)
430             len = sizeof buf;
431         cpu_physical_memory_read (saved_data_buf, buf, len);
432 
433         out_eop = ((saved_data_buf + len) ==
434                    ctrl->channels[c].current_d.after) &&
435                    ctrl->channels[c].current_d.out_eop;
436 
437         D(printf("channel %d pushes %x %u bytes eop=%u\n", c,
438                  saved_data_buf, len, out_eop));
439 
440         if (ctrl->channels[c].client->client.push) {
441             if (len > 0) {
442                 ctrl->channels[c].client->client.push(
443                     ctrl->channels[c].client->client.opaque,
444                     buf, len, out_eop);
445             }
446         } else {
447             printf("WARNING: DMA ch%d dataloss,"
448                    " no attached client.\n", c);
449         }
450 
451         saved_data_buf += len;
452 
453         if (saved_data_buf == (uint32_t)(unsigned long)
454                 ctrl->channels[c].current_d.after) {
455             /* Done. Step to next.  */
456             if (ctrl->channels[c].current_d.out_eop) {
457                 send_context = true;
458             }
459             if (ctrl->channels[c].current_d.intr) {
460                 /* data intr.  */
461                 D(printf("signal intr %d eol=%d\n",
462                          len, ctrl->channels[c].current_d.eol));
463                 ctrl->channels[c].regs[R_INTR] |= (1 << 2);
464                 channel_update_irq(ctrl, c);
465             }
466             channel_store_d(ctrl, c);
467             if (ctrl->channels[c].current_d.eol) {
468                 D(printf("channel %d EOL\n", c));
469                 ctrl->channels[c].eol = 1;
470 
471                 /* Mark the context as disabled.  */
472                 ctrl->channels[c].current_c.dis = 1;
473                 channel_store_c(ctrl, c);
474 
475                 channel_stop(ctrl, c);
476             } else {
477                 ctrl->channels[c].regs[RW_SAVED_DATA] =
478                     (uint32_t)(unsigned long)ctrl->
479                         channels[c].current_d.next;
480                 /* Load new descriptor.  */
481                 channel_load_d(ctrl, c);
482                 saved_data_buf = (uint32_t)(unsigned long)
483                     ctrl->channels[c].current_d.buf;
484             }
485 
486             ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
487                             saved_data_buf;
488             D(dump_d(c, &ctrl->channels[c].current_d));
489         }
490         ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
491     } while (!ctrl->channels[c].eol);
492     return 1;
493 }
494 
495 static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
496                               unsigned char *buf, int buflen, int eop)
497 {
498     uint32_t len;
499     uint32_t saved_data_buf;
500 
501     if (ctrl->channels[c].eol == 1)
502         return 0;
503 
504     channel_load_d(ctrl, c);
505     saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
506     len = (uint32_t)(unsigned long)ctrl->channels[c].current_d.after;
507     len -= saved_data_buf;
508 
509     if (len > buflen)
510         len = buflen;
511 
512     cpu_physical_memory_write (saved_data_buf, buf, len);
513     saved_data_buf += len;
514 
515     if (saved_data_buf ==
516         (uint32_t)(unsigned long)ctrl->channels[c].current_d.after
517         || eop) {
518         uint32_t r_intr = ctrl->channels[c].regs[R_INTR];
519 
520         D(printf("in dscr end len=%d\n",
521                  ctrl->channels[c].current_d.after
522                  - ctrl->channels[c].current_d.buf));
523         ctrl->channels[c].current_d.after = saved_data_buf;
524 
525         /* Done. Step to next.  */
526         if (ctrl->channels[c].current_d.intr) {
527             /* TODO: signal eop to the client.  */
528             /* data intr.  */
529             ctrl->channels[c].regs[R_INTR] |= 3;
530         }
531         if (eop) {
532             ctrl->channels[c].current_d.in_eop = 1;
533             ctrl->channels[c].regs[R_INTR] |= 8;
534         }
535         if (r_intr != ctrl->channels[c].regs[R_INTR])
536             channel_update_irq(ctrl, c);
537 
538         channel_store_d(ctrl, c);
539         D(dump_d(c, &ctrl->channels[c].current_d));
540 
541         if (ctrl->channels[c].current_d.eol) {
542             D(printf("channel %d EOL\n", c));
543             ctrl->channels[c].eol = 1;
544 
545             /* Mark the context as disabled.  */
546             ctrl->channels[c].current_c.dis = 1;
547             channel_store_c(ctrl, c);
548 
549             channel_stop(ctrl, c);
550         } else {
551             ctrl->channels[c].regs[RW_SAVED_DATA] =
552                 (uint32_t)(unsigned long)ctrl->
553                     channels[c].current_d.next;
554             /* Load new descriptor.  */
555             channel_load_d(ctrl, c);
556             saved_data_buf = (uint32_t)(unsigned long)
557                 ctrl->channels[c].current_d.buf;
558         }
559     }
560 
561     ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
562     return len;
563 }
564 
565 static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
566 {
567     if (ctrl->channels[c].client->client.pull) {
568         ctrl->channels[c].client->client.pull(
569             ctrl->channels[c].client->client.opaque);
570         return 1;
571     } else
572         return 0;
573 }
574 
575 static uint32_t dma_rinvalid (void *opaque, hwaddr addr)
576 {
577     hw_error("Unsupported short raccess. reg=" HWADDR_FMT_plx "\n", addr);
578     return 0;
579 }
580 
581 static uint64_t
582 dma_read(void *opaque, hwaddr addr, unsigned int size)
583 {
584     struct fs_dma_ctrl *ctrl = opaque;
585     int c;
586     uint32_t r = 0;
587 
588     if (size != 4) {
589         dma_rinvalid(opaque, addr);
590     }
591 
592     /* Make addr relative to this channel and bounded to nr regs.  */
593     c = fs_channel(addr);
594     addr &= 0xff;
595     addr >>= 2;
596     switch (addr)
597     {
598     case RW_STAT:
599         r = ctrl->channels[c].state & 7;
600         r |= ctrl->channels[c].eol << 5;
601         r |= ctrl->channels[c].stream_cmd_src << 8;
602         break;
603 
604     default:
605         r = ctrl->channels[c].regs[addr];
606         D(printf("%s c=%d addr=" HWADDR_FMT_plx "\n",
607                  __func__, c, addr));
608         break;
609     }
610     return r;
611 }
612 
613 static void
614 dma_winvalid (void *opaque, hwaddr addr, uint32_t value)
615 {
616     hw_error("Unsupported short waccess. reg=" HWADDR_FMT_plx "\n", addr);
617 }
618 
619 static void
620 dma_update_state(struct fs_dma_ctrl *ctrl, int c)
621 {
622     if (ctrl->channels[c].regs[RW_CFG] & 2)
623         ctrl->channels[c].state = STOPPED;
624     if (!(ctrl->channels[c].regs[RW_CFG] & 1))
625         ctrl->channels[c].state = RST;
626 }
627 
628 static void
629 dma_write(void *opaque, hwaddr addr,
630           uint64_t val64, unsigned int size)
631 {
632     struct fs_dma_ctrl *ctrl = opaque;
633     uint32_t value = val64;
634     int c;
635 
636     if (size != 4) {
637         dma_winvalid(opaque, addr, value);
638     }
639 
640         /* Make addr relative to this channel and bounded to nr regs.  */
641     c = fs_channel(addr);
642     addr &= 0xff;
643     addr >>= 2;
644     switch (addr)
645     {
646     case RW_DATA:
647         ctrl->channels[c].regs[addr] = value;
648         break;
649 
650     case RW_CFG:
651         ctrl->channels[c].regs[addr] = value;
652         dma_update_state(ctrl, c);
653         break;
654     case RW_CMD:
655         /* continue.  */
656         if (value & ~1)
657             printf("Invalid store to ch=%d RW_CMD %x\n",
658                    c, value);
659         ctrl->channels[c].regs[addr] = value;
660         channel_continue(ctrl, c);
661         break;
662 
663     case RW_SAVED_DATA:
664     case RW_SAVED_DATA_BUF:
665     case RW_GROUP:
666     case RW_GROUP_DOWN:
667         ctrl->channels[c].regs[addr] = value;
668         break;
669 
670     case RW_ACK_INTR:
671     case RW_INTR_MASK:
672         ctrl->channels[c].regs[addr] = value;
673         channel_update_irq(ctrl, c);
674         if (addr == RW_ACK_INTR)
675             ctrl->channels[c].regs[RW_ACK_INTR] = 0;
676         break;
677 
678     case RW_STREAM_CMD:
679         if (value & ~1023)
680             printf("Invalid store to ch=%d "
681                    "RW_STREAMCMD %x\n",
682                    c, value);
683         ctrl->channels[c].regs[addr] = value;
684         D(printf("stream_cmd ch=%d\n", c));
685         channel_stream_cmd(ctrl, c, value);
686         break;
687 
688     default:
689         D(printf("%s c=%d " HWADDR_FMT_plx "\n",
690                  __func__, c, addr));
691         break;
692     }
693 }
694 
695 static const MemoryRegionOps dma_ops = {
696     .read = dma_read,
697     .write = dma_write,
698     .endianness = DEVICE_NATIVE_ENDIAN,
699     .valid = {
700         .min_access_size = 1,
701         .max_access_size = 4
702     }
703 };
704 
705 static int etraxfs_dmac_run(void *opaque)
706 {
707     struct fs_dma_ctrl *ctrl = opaque;
708     int i;
709     int p = 0;
710 
711     for (i = 0;
712          i < ctrl->nr_channels;
713          i++)
714     {
715         if (ctrl->channels[i].state == RUNNING)
716         {
717             if (ctrl->channels[i].input) {
718                 p += channel_in_run(ctrl, i);
719             } else {
720                 p += channel_out_run(ctrl, i);
721             }
722         }
723     }
724     return p;
725 }
726 
727 int etraxfs_dmac_input(struct etraxfs_dma_client *client,
728                        void *buf, int len, int eop)
729 {
730     return channel_in_process(client->ctrl, client->channel,
731                               buf, len, eop);
732 }
733 
734 /* Connect an IRQ line with a channel.  */
735 void etraxfs_dmac_connect(void *opaque, int c, qemu_irq *line, int input)
736 {
737     struct fs_dma_ctrl *ctrl = opaque;
738     ctrl->channels[c].irq = *line;
739     ctrl->channels[c].input = input;
740 }
741 
742 void etraxfs_dmac_connect_client(void *opaque, int c,
743                                  struct etraxfs_dma_client *cl)
744 {
745     struct fs_dma_ctrl *ctrl = opaque;
746     cl->ctrl = ctrl;
747     cl->channel = c;
748     ctrl->channels[c].client = cl;
749 }
750 
751 
752 static void DMA_run(void *opaque)
753 {
754     struct fs_dma_ctrl *etraxfs_dmac = opaque;
755     int p = 1;
756 
757     if (runstate_is_running())
758         p = etraxfs_dmac_run(etraxfs_dmac);
759 
760     if (p)
761         qemu_bh_schedule_idle(etraxfs_dmac->bh);
762 }
763 
764 void *etraxfs_dmac_init(hwaddr base, int nr_channels)
765 {
766     struct fs_dma_ctrl *ctrl = NULL;
767 
768     ctrl = g_malloc0(sizeof *ctrl);
769 
770     ctrl->bh = qemu_bh_new(DMA_run, ctrl);
771 
772     ctrl->nr_channels = nr_channels;
773     ctrl->channels = g_malloc0(sizeof ctrl->channels[0] * nr_channels);
774 
775     memory_region_init_io(&ctrl->mmio, NULL, &dma_ops, ctrl, "etraxfs-dma",
776                           nr_channels * 0x2000);
777     memory_region_add_subregion(get_system_memory(), base, &ctrl->mmio);
778 
779     return ctrl;
780 }
781