xref: /openbmc/qemu/hw/dma/xilinx_axidma.c (revision 47451466)
1 /*
2  * QEMU model of Xilinx AXI-DMA block.
3  *
4  * Copyright (c) 2011 Edgar E. Iglesias.
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/sysbus.h"
27 #include "qapi/error.h"
28 #include "qemu/timer.h"
29 #include "hw/ptimer.h"
30 #include "qemu/log.h"
31 #include "qemu/main-loop.h"
32 
33 #include "hw/stream.h"
34 
35 #define D(x)
36 
37 #define TYPE_XILINX_AXI_DMA "xlnx.axi-dma"
38 #define TYPE_XILINX_AXI_DMA_DATA_STREAM "xilinx-axi-dma-data-stream"
39 #define TYPE_XILINX_AXI_DMA_CONTROL_STREAM "xilinx-axi-dma-control-stream"
40 
41 #define XILINX_AXI_DMA(obj) \
42      OBJECT_CHECK(XilinxAXIDMA, (obj), TYPE_XILINX_AXI_DMA)
43 
44 #define XILINX_AXI_DMA_DATA_STREAM(obj) \
45      OBJECT_CHECK(XilinxAXIDMAStreamSlave, (obj),\
46      TYPE_XILINX_AXI_DMA_DATA_STREAM)
47 
48 #define XILINX_AXI_DMA_CONTROL_STREAM(obj) \
49      OBJECT_CHECK(XilinxAXIDMAStreamSlave, (obj),\
50      TYPE_XILINX_AXI_DMA_CONTROL_STREAM)
51 
52 #define R_DMACR             (0x00 / 4)
53 #define R_DMASR             (0x04 / 4)
54 #define R_CURDESC           (0x08 / 4)
55 #define R_TAILDESC          (0x10 / 4)
56 #define R_MAX               (0x30 / 4)
57 
58 #define CONTROL_PAYLOAD_WORDS 5
59 #define CONTROL_PAYLOAD_SIZE (CONTROL_PAYLOAD_WORDS * (sizeof(uint32_t)))
60 
61 typedef struct XilinxAXIDMA XilinxAXIDMA;
62 typedef struct XilinxAXIDMAStreamSlave XilinxAXIDMAStreamSlave;
63 
64 enum {
65     DMACR_RUNSTOP = 1,
66     DMACR_TAILPTR_MODE = 2,
67     DMACR_RESET = 4
68 };
69 
70 enum {
71     DMASR_HALTED = 1,
72     DMASR_IDLE  = 2,
73     DMASR_IOC_IRQ  = 1 << 12,
74     DMASR_DLY_IRQ  = 1 << 13,
75 
76     DMASR_IRQ_MASK = 7 << 12
77 };
78 
79 struct SDesc {
80     uint64_t nxtdesc;
81     uint64_t buffer_address;
82     uint64_t reserved;
83     uint32_t control;
84     uint32_t status;
85     uint8_t app[CONTROL_PAYLOAD_SIZE];
86 };
87 
88 enum {
89     SDESC_CTRL_EOF = (1 << 26),
90     SDESC_CTRL_SOF = (1 << 27),
91 
92     SDESC_CTRL_LEN_MASK = (1 << 23) - 1
93 };
94 
95 enum {
96     SDESC_STATUS_EOF = (1 << 26),
97     SDESC_STATUS_SOF_BIT = 27,
98     SDESC_STATUS_SOF = (1 << SDESC_STATUS_SOF_BIT),
99     SDESC_STATUS_COMPLETE = (1 << 31)
100 };
101 
102 struct Stream {
103     QEMUBH *bh;
104     ptimer_state *ptimer;
105     qemu_irq irq;
106 
107     int nr;
108 
109     struct SDesc desc;
110     int pos;
111     unsigned int complete_cnt;
112     uint32_t regs[R_MAX];
113     uint8_t app[20];
114     unsigned char txbuf[16 * 1024];
115 };
116 
117 struct XilinxAXIDMAStreamSlave {
118     Object parent;
119 
120     struct XilinxAXIDMA *dma;
121 };
122 
123 struct XilinxAXIDMA {
124     SysBusDevice busdev;
125     MemoryRegion iomem;
126     uint32_t freqhz;
127     StreamSlave *tx_data_dev;
128     StreamSlave *tx_control_dev;
129     XilinxAXIDMAStreamSlave rx_data_dev;
130     XilinxAXIDMAStreamSlave rx_control_dev;
131 
132     struct Stream streams[2];
133 
134     StreamCanPushNotifyFn notify;
135     void *notify_opaque;
136 };
137 
138 /*
139  * Helper calls to extract info from descriptors and other trivial
140  * state from regs.
141  */
142 static inline int stream_desc_sof(struct SDesc *d)
143 {
144     return d->control & SDESC_CTRL_SOF;
145 }
146 
147 static inline int stream_desc_eof(struct SDesc *d)
148 {
149     return d->control & SDESC_CTRL_EOF;
150 }
151 
152 static inline int stream_resetting(struct Stream *s)
153 {
154     return !!(s->regs[R_DMACR] & DMACR_RESET);
155 }
156 
157 static inline int stream_running(struct Stream *s)
158 {
159     return s->regs[R_DMACR] & DMACR_RUNSTOP;
160 }
161 
162 static inline int stream_idle(struct Stream *s)
163 {
164     return !!(s->regs[R_DMASR] & DMASR_IDLE);
165 }
166 
167 static void stream_reset(struct Stream *s)
168 {
169     s->regs[R_DMASR] = DMASR_HALTED;  /* starts up halted.  */
170     s->regs[R_DMACR] = 1 << 16; /* Starts with one in compl threshold.  */
171 }
172 
173 /* Map an offset addr into a channel index.  */
174 static inline int streamid_from_addr(hwaddr addr)
175 {
176     int sid;
177 
178     sid = addr / (0x30);
179     sid &= 1;
180     return sid;
181 }
182 
183 static void stream_desc_load(struct Stream *s, hwaddr addr)
184 {
185     struct SDesc *d = &s->desc;
186 
187     cpu_physical_memory_read(addr, d, sizeof *d);
188 
189     /* Convert from LE into host endianness.  */
190     d->buffer_address = le64_to_cpu(d->buffer_address);
191     d->nxtdesc = le64_to_cpu(d->nxtdesc);
192     d->control = le32_to_cpu(d->control);
193     d->status = le32_to_cpu(d->status);
194 }
195 
196 static void stream_desc_store(struct Stream *s, hwaddr addr)
197 {
198     struct SDesc *d = &s->desc;
199 
200     /* Convert from host endianness into LE.  */
201     d->buffer_address = cpu_to_le64(d->buffer_address);
202     d->nxtdesc = cpu_to_le64(d->nxtdesc);
203     d->control = cpu_to_le32(d->control);
204     d->status = cpu_to_le32(d->status);
205     cpu_physical_memory_write(addr, d, sizeof *d);
206 }
207 
208 static void stream_update_irq(struct Stream *s)
209 {
210     unsigned int pending, mask, irq;
211 
212     pending = s->regs[R_DMASR] & DMASR_IRQ_MASK;
213     mask = s->regs[R_DMACR] & DMASR_IRQ_MASK;
214 
215     irq = pending & mask;
216 
217     qemu_set_irq(s->irq, !!irq);
218 }
219 
220 static void stream_reload_complete_cnt(struct Stream *s)
221 {
222     unsigned int comp_th;
223     comp_th = (s->regs[R_DMACR] >> 16) & 0xff;
224     s->complete_cnt = comp_th;
225 }
226 
227 static void timer_hit(void *opaque)
228 {
229     struct Stream *s = opaque;
230 
231     stream_reload_complete_cnt(s);
232     s->regs[R_DMASR] |= DMASR_DLY_IRQ;
233     stream_update_irq(s);
234 }
235 
236 static void stream_complete(struct Stream *s)
237 {
238     unsigned int comp_delay;
239 
240     /* Start the delayed timer.  */
241     comp_delay = s->regs[R_DMACR] >> 24;
242     if (comp_delay) {
243         ptimer_stop(s->ptimer);
244         ptimer_set_count(s->ptimer, comp_delay);
245         ptimer_run(s->ptimer, 1);
246     }
247 
248     s->complete_cnt--;
249     if (s->complete_cnt == 0) {
250         /* Raise the IOC irq.  */
251         s->regs[R_DMASR] |= DMASR_IOC_IRQ;
252         stream_reload_complete_cnt(s);
253     }
254 }
255 
256 static void stream_process_mem2s(struct Stream *s, StreamSlave *tx_data_dev,
257                                  StreamSlave *tx_control_dev)
258 {
259     uint32_t prev_d;
260     unsigned int txlen;
261 
262     if (!stream_running(s) || stream_idle(s)) {
263         return;
264     }
265 
266     while (1) {
267         stream_desc_load(s, s->regs[R_CURDESC]);
268 
269         if (s->desc.status & SDESC_STATUS_COMPLETE) {
270             s->regs[R_DMASR] |= DMASR_HALTED;
271             break;
272         }
273 
274         if (stream_desc_sof(&s->desc)) {
275             s->pos = 0;
276             stream_push(tx_control_dev, s->desc.app, sizeof(s->desc.app));
277         }
278 
279         txlen = s->desc.control & SDESC_CTRL_LEN_MASK;
280         if ((txlen + s->pos) > sizeof s->txbuf) {
281             hw_error("%s: too small internal txbuf! %d\n", __func__,
282                      txlen + s->pos);
283         }
284 
285         cpu_physical_memory_read(s->desc.buffer_address,
286                                  s->txbuf + s->pos, txlen);
287         s->pos += txlen;
288 
289         if (stream_desc_eof(&s->desc)) {
290             stream_push(tx_data_dev, s->txbuf, s->pos);
291             s->pos = 0;
292             stream_complete(s);
293         }
294 
295         /* Update the descriptor.  */
296         s->desc.status = txlen | SDESC_STATUS_COMPLETE;
297         stream_desc_store(s, s->regs[R_CURDESC]);
298 
299         /* Advance.  */
300         prev_d = s->regs[R_CURDESC];
301         s->regs[R_CURDESC] = s->desc.nxtdesc;
302         if (prev_d == s->regs[R_TAILDESC]) {
303             s->regs[R_DMASR] |= DMASR_IDLE;
304             break;
305         }
306     }
307 }
308 
309 static size_t stream_process_s2mem(struct Stream *s, unsigned char *buf,
310                                    size_t len)
311 {
312     uint32_t prev_d;
313     unsigned int rxlen;
314     size_t pos = 0;
315     int sof = 1;
316 
317     if (!stream_running(s) || stream_idle(s)) {
318         return 0;
319     }
320 
321     while (len) {
322         stream_desc_load(s, s->regs[R_CURDESC]);
323 
324         if (s->desc.status & SDESC_STATUS_COMPLETE) {
325             s->regs[R_DMASR] |= DMASR_HALTED;
326             break;
327         }
328 
329         rxlen = s->desc.control & SDESC_CTRL_LEN_MASK;
330         if (rxlen > len) {
331             /* It fits.  */
332             rxlen = len;
333         }
334 
335         cpu_physical_memory_write(s->desc.buffer_address, buf + pos, rxlen);
336         len -= rxlen;
337         pos += rxlen;
338 
339         /* Update the descriptor.  */
340         if (!len) {
341             stream_complete(s);
342             memcpy(s->desc.app, s->app, sizeof(s->desc.app));
343             s->desc.status |= SDESC_STATUS_EOF;
344         }
345 
346         s->desc.status |= sof << SDESC_STATUS_SOF_BIT;
347         s->desc.status |= SDESC_STATUS_COMPLETE;
348         stream_desc_store(s, s->regs[R_CURDESC]);
349         sof = 0;
350 
351         /* Advance.  */
352         prev_d = s->regs[R_CURDESC];
353         s->regs[R_CURDESC] = s->desc.nxtdesc;
354         if (prev_d == s->regs[R_TAILDESC]) {
355             s->regs[R_DMASR] |= DMASR_IDLE;
356             break;
357         }
358     }
359 
360     return pos;
361 }
362 
363 static void xilinx_axidma_reset(DeviceState *dev)
364 {
365     int i;
366     XilinxAXIDMA *s = XILINX_AXI_DMA(dev);
367 
368     for (i = 0; i < 2; i++) {
369         stream_reset(&s->streams[i]);
370     }
371 }
372 
373 static size_t
374 xilinx_axidma_control_stream_push(StreamSlave *obj, unsigned char *buf,
375                                   size_t len)
376 {
377     XilinxAXIDMAStreamSlave *cs = XILINX_AXI_DMA_CONTROL_STREAM(obj);
378     struct Stream *s = &cs->dma->streams[1];
379 
380     if (len != CONTROL_PAYLOAD_SIZE) {
381         hw_error("AXI DMA requires %d byte control stream payload\n",
382                  (int)CONTROL_PAYLOAD_SIZE);
383     }
384 
385     memcpy(s->app, buf, len);
386     return len;
387 }
388 
389 static bool
390 xilinx_axidma_data_stream_can_push(StreamSlave *obj,
391                                    StreamCanPushNotifyFn notify,
392                                    void *notify_opaque)
393 {
394     XilinxAXIDMAStreamSlave *ds = XILINX_AXI_DMA_DATA_STREAM(obj);
395     struct Stream *s = &ds->dma->streams[1];
396 
397     if (!stream_running(s) || stream_idle(s)) {
398         ds->dma->notify = notify;
399         ds->dma->notify_opaque = notify_opaque;
400         return false;
401     }
402 
403     return true;
404 }
405 
406 static size_t
407 xilinx_axidma_data_stream_push(StreamSlave *obj, unsigned char *buf, size_t len)
408 {
409     XilinxAXIDMAStreamSlave *ds = XILINX_AXI_DMA_DATA_STREAM(obj);
410     struct Stream *s = &ds->dma->streams[1];
411     size_t ret;
412 
413     ret = stream_process_s2mem(s, buf, len);
414     stream_update_irq(s);
415     return ret;
416 }
417 
418 static uint64_t axidma_read(void *opaque, hwaddr addr,
419                             unsigned size)
420 {
421     XilinxAXIDMA *d = opaque;
422     struct Stream *s;
423     uint32_t r = 0;
424     int sid;
425 
426     sid = streamid_from_addr(addr);
427     s = &d->streams[sid];
428 
429     addr = addr % 0x30;
430     addr >>= 2;
431     switch (addr) {
432         case R_DMACR:
433             /* Simulate one cycles reset delay.  */
434             s->regs[addr] &= ~DMACR_RESET;
435             r = s->regs[addr];
436             break;
437         case R_DMASR:
438             s->regs[addr] &= 0xffff;
439             s->regs[addr] |= (s->complete_cnt & 0xff) << 16;
440             s->regs[addr] |= (ptimer_get_count(s->ptimer) & 0xff) << 24;
441             r = s->regs[addr];
442             break;
443         default:
444             r = s->regs[addr];
445             D(qemu_log("%s ch=%d addr=" TARGET_FMT_plx " v=%x\n",
446                            __func__, sid, addr * 4, r));
447             break;
448     }
449     return r;
450 
451 }
452 
453 static void axidma_write(void *opaque, hwaddr addr,
454                          uint64_t value, unsigned size)
455 {
456     XilinxAXIDMA *d = opaque;
457     struct Stream *s;
458     int sid;
459 
460     sid = streamid_from_addr(addr);
461     s = &d->streams[sid];
462 
463     addr = addr % 0x30;
464     addr >>= 2;
465     switch (addr) {
466         case R_DMACR:
467             /* Tailptr mode is always on.  */
468             value |= DMACR_TAILPTR_MODE;
469             /* Remember our previous reset state.  */
470             value |= (s->regs[addr] & DMACR_RESET);
471             s->regs[addr] = value;
472 
473             if (value & DMACR_RESET) {
474                 stream_reset(s);
475             }
476 
477             if ((value & 1) && !stream_resetting(s)) {
478                 /* Start processing.  */
479                 s->regs[R_DMASR] &= ~(DMASR_HALTED | DMASR_IDLE);
480             }
481             stream_reload_complete_cnt(s);
482             break;
483 
484         case R_DMASR:
485             /* Mask away write to clear irq lines.  */
486             value &= ~(value & DMASR_IRQ_MASK);
487             s->regs[addr] = value;
488             break;
489 
490         case R_TAILDESC:
491             s->regs[addr] = value;
492             s->regs[R_DMASR] &= ~DMASR_IDLE; /* Not idle.  */
493             if (!sid) {
494                 stream_process_mem2s(s, d->tx_data_dev, d->tx_control_dev);
495             }
496             break;
497         default:
498             D(qemu_log("%s: ch=%d addr=" TARGET_FMT_plx " v=%x\n",
499                   __func__, sid, addr * 4, (unsigned)value));
500             s->regs[addr] = value;
501             break;
502     }
503     if (sid == 1 && d->notify) {
504         StreamCanPushNotifyFn notifytmp = d->notify;
505         d->notify = NULL;
506         notifytmp(d->notify_opaque);
507     }
508     stream_update_irq(s);
509 }
510 
511 static const MemoryRegionOps axidma_ops = {
512     .read = axidma_read,
513     .write = axidma_write,
514     .endianness = DEVICE_NATIVE_ENDIAN,
515 };
516 
517 static void xilinx_axidma_realize(DeviceState *dev, Error **errp)
518 {
519     XilinxAXIDMA *s = XILINX_AXI_DMA(dev);
520     XilinxAXIDMAStreamSlave *ds = XILINX_AXI_DMA_DATA_STREAM(&s->rx_data_dev);
521     XilinxAXIDMAStreamSlave *cs = XILINX_AXI_DMA_CONTROL_STREAM(
522                                                             &s->rx_control_dev);
523     Error *local_err = NULL;
524 
525     object_property_add_link(OBJECT(ds), "dma", TYPE_XILINX_AXI_DMA,
526                              (Object **)&ds->dma,
527                              object_property_allow_set_link,
528                              OBJ_PROP_LINK_STRONG,
529                              &local_err);
530     object_property_add_link(OBJECT(cs), "dma", TYPE_XILINX_AXI_DMA,
531                              (Object **)&cs->dma,
532                              object_property_allow_set_link,
533                              OBJ_PROP_LINK_STRONG,
534                              &local_err);
535     if (local_err) {
536         goto xilinx_axidma_realize_fail;
537     }
538     object_property_set_link(OBJECT(ds), OBJECT(s), "dma", &local_err);
539     object_property_set_link(OBJECT(cs), OBJECT(s), "dma", &local_err);
540     if (local_err) {
541         goto xilinx_axidma_realize_fail;
542     }
543 
544     int i;
545 
546     for (i = 0; i < 2; i++) {
547         struct Stream *st = &s->streams[i];
548 
549         st->nr = i;
550         st->bh = qemu_bh_new(timer_hit, st);
551         st->ptimer = ptimer_init(st->bh, PTIMER_POLICY_DEFAULT);
552         ptimer_set_freq(st->ptimer, s->freqhz);
553     }
554     return;
555 
556 xilinx_axidma_realize_fail:
557     error_propagate(errp, local_err);
558 }
559 
560 static void xilinx_axidma_init(Object *obj)
561 {
562     XilinxAXIDMA *s = XILINX_AXI_DMA(obj);
563     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
564 
565     object_initialize(&s->rx_data_dev, sizeof(s->rx_data_dev),
566                       TYPE_XILINX_AXI_DMA_DATA_STREAM);
567     object_initialize(&s->rx_control_dev, sizeof(s->rx_control_dev),
568                       TYPE_XILINX_AXI_DMA_CONTROL_STREAM);
569     object_property_add_child(OBJECT(s), "axistream-connected-target",
570                               (Object *)&s->rx_data_dev, &error_abort);
571     object_property_add_child(OBJECT(s), "axistream-control-connected-target",
572                               (Object *)&s->rx_control_dev, &error_abort);
573 
574     sysbus_init_irq(sbd, &s->streams[0].irq);
575     sysbus_init_irq(sbd, &s->streams[1].irq);
576 
577     memory_region_init_io(&s->iomem, obj, &axidma_ops, s,
578                           "xlnx.axi-dma", R_MAX * 4 * 2);
579     sysbus_init_mmio(sbd, &s->iomem);
580 }
581 
582 static Property axidma_properties[] = {
583     DEFINE_PROP_UINT32("freqhz", XilinxAXIDMA, freqhz, 50000000),
584     DEFINE_PROP_LINK("axistream-connected", XilinxAXIDMA,
585                      tx_data_dev, TYPE_STREAM_SLAVE, StreamSlave *),
586     DEFINE_PROP_LINK("axistream-control-connected", XilinxAXIDMA,
587                      tx_control_dev, TYPE_STREAM_SLAVE, StreamSlave *),
588     DEFINE_PROP_END_OF_LIST(),
589 };
590 
591 static void axidma_class_init(ObjectClass *klass, void *data)
592 {
593     DeviceClass *dc = DEVICE_CLASS(klass);
594 
595     dc->realize = xilinx_axidma_realize,
596     dc->reset = xilinx_axidma_reset;
597     dc->props = axidma_properties;
598 }
599 
600 static StreamSlaveClass xilinx_axidma_data_stream_class = {
601     .push = xilinx_axidma_data_stream_push,
602     .can_push = xilinx_axidma_data_stream_can_push,
603 };
604 
605 static StreamSlaveClass xilinx_axidma_control_stream_class = {
606     .push = xilinx_axidma_control_stream_push,
607 };
608 
609 static void xilinx_axidma_stream_class_init(ObjectClass *klass, void *data)
610 {
611     StreamSlaveClass *ssc = STREAM_SLAVE_CLASS(klass);
612 
613     ssc->push = ((StreamSlaveClass *)data)->push;
614     ssc->can_push = ((StreamSlaveClass *)data)->can_push;
615 }
616 
617 static const TypeInfo axidma_info = {
618     .name          = TYPE_XILINX_AXI_DMA,
619     .parent        = TYPE_SYS_BUS_DEVICE,
620     .instance_size = sizeof(XilinxAXIDMA),
621     .class_init    = axidma_class_init,
622     .instance_init = xilinx_axidma_init,
623 };
624 
625 static const TypeInfo xilinx_axidma_data_stream_info = {
626     .name          = TYPE_XILINX_AXI_DMA_DATA_STREAM,
627     .parent        = TYPE_OBJECT,
628     .instance_size = sizeof(struct XilinxAXIDMAStreamSlave),
629     .class_init    = xilinx_axidma_stream_class_init,
630     .class_data    = &xilinx_axidma_data_stream_class,
631     .interfaces = (InterfaceInfo[]) {
632         { TYPE_STREAM_SLAVE },
633         { }
634     }
635 };
636 
637 static const TypeInfo xilinx_axidma_control_stream_info = {
638     .name          = TYPE_XILINX_AXI_DMA_CONTROL_STREAM,
639     .parent        = TYPE_OBJECT,
640     .instance_size = sizeof(struct XilinxAXIDMAStreamSlave),
641     .class_init    = xilinx_axidma_stream_class_init,
642     .class_data    = &xilinx_axidma_control_stream_class,
643     .interfaces = (InterfaceInfo[]) {
644         { TYPE_STREAM_SLAVE },
645         { }
646     }
647 };
648 
649 static void xilinx_axidma_register_types(void)
650 {
651     type_register_static(&axidma_info);
652     type_register_static(&xilinx_axidma_data_stream_info);
653     type_register_static(&xilinx_axidma_control_stream_info);
654 }
655 
656 type_init(xilinx_axidma_register_types)
657