virtio.c revision 1.16.2.1 1 /* $NetBSD: virtio.c,v 1.16.2.1 2016/11/04 14:49:15 pgoyette Exp $ */
2
3 /*
4 * Copyright (c) 2010 Minoura Makoto.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: virtio.c,v 1.16.2.1 2016/11/04 14:49:15 pgoyette Exp $");
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/atomic.h>
35 #include <sys/bus.h>
36 #include <sys/device.h>
37 #include <sys/kmem.h>
38 #include <sys/module.h>
39
40 #include <dev/pci/pcidevs.h>
41 #include <dev/pci/pcireg.h>
42 #include <dev/pci/pcivar.h>
43
44 #include <dev/pci/virtioreg.h>
45 #include <dev/pci/virtiovar.h>
46
47 #define MINSEG_INDIRECT 2 /* use indirect if nsegs >= this value */
48
49 static int virtio_match(device_t, cfdata_t, void *);
50 static void virtio_attach(device_t, device_t, void *);
51 static int virtio_rescan(device_t, const char *, const int *);
52 static int virtio_detach(device_t, int);
53 static int virtio_intr(void *arg);
54 static int virtio_msix_queue_intr(void *);
55 static int virtio_msix_config_intr(void *);
56 static int virtio_setup_msix_vectors(struct virtio_softc *);
57 static int virtio_setup_msix_interrupts(struct virtio_softc *,
58 struct pci_attach_args *);
59 static int virtio_setup_intx_interrupt(struct virtio_softc *,
60 struct pci_attach_args *);
61 static int virtio_setup_interrupts(struct virtio_softc *);
62 static void virtio_soft_intr(void *arg);
63 static void virtio_init_vq(struct virtio_softc *,
64 struct virtqueue *, const bool);
65
66 CFATTACH_DECL3_NEW(virtio, sizeof(struct virtio_softc),
67 virtio_match, virtio_attach, virtio_detach, NULL, virtio_rescan, NULL,
68 DVF_DETACH_SHUTDOWN);
69
70 static void
71 virtio_set_status(struct virtio_softc *sc, int status)
72 {
73 int old = 0;
74
75 if (status != 0)
76 old = bus_space_read_1(sc->sc_iot, sc->sc_ioh,
77 VIRTIO_CONFIG_DEVICE_STATUS);
78 bus_space_write_1(sc->sc_iot, sc->sc_ioh, VIRTIO_CONFIG_DEVICE_STATUS,
79 status|old);
80 }
81
82 #define virtio_device_reset(sc) virtio_set_status((sc), 0)
83
84 static int
85 virtio_match(device_t parent, cfdata_t match, void *aux)
86 {
87 struct pci_attach_args *pa;
88
89 pa = (struct pci_attach_args *)aux;
90 switch (PCI_VENDOR(pa->pa_id)) {
91 case PCI_VENDOR_QUMRANET:
92 if ((PCI_PRODUCT_QUMRANET_VIRTIO_1000 <=
93 PCI_PRODUCT(pa->pa_id)) &&
94 (PCI_PRODUCT(pa->pa_id) <=
95 PCI_PRODUCT_QUMRANET_VIRTIO_103F))
96 return 1;
97 break;
98 }
99
100 return 0;
101 }
102
103 static const char *virtio_device_name[] = {
104 "Unknown (0)", /* 0 */
105 "Network", /* 1 */
106 "Block", /* 2 */
107 "Console", /* 3 */
108 "Entropy", /* 4 */
109 "Memory Balloon", /* 5 */
110 "I/O Memory", /* 6 */
111 "Remote Processor Messaging", /* 7 */
112 "SCSI", /* 8 */
113 "9P Transport", /* 9 */
114 "mac80211 wlan", /* 10 */
115 };
116 #define NDEVNAMES __arraycount(virtio_device_name)
117
118 #define VIRTIO_MSIX_CONFIG_VECTOR_INDEX 0
119 #define VIRTIO_MSIX_QUEUE_VECTOR_INDEX 1
120
121 static int
122 virtio_setup_msix_vectors(struct virtio_softc *sc)
123 {
124 int offset, vector, ret, qid;
125
126 offset = VIRTIO_CONFIG_MSI_CONFIG_VECTOR;
127 vector = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
128
129 bus_space_write_2(sc->sc_iot, sc->sc_ioh, offset, vector);
130 ret = bus_space_read_2(sc->sc_iot, sc->sc_ioh, offset);
131 aprint_debug_dev(sc->sc_dev, "expected=%d, actual=%d\n",
132 vector, ret);
133 if (ret != vector)
134 return -1;
135
136 for (qid = 0; qid < sc->sc_nvqs; qid++) {
137 offset = VIRTIO_CONFIG_QUEUE_SELECT;
138 bus_space_write_2(sc->sc_iot, sc->sc_ioh, offset, qid);
139
140 offset = VIRTIO_CONFIG_MSI_QUEUE_VECTOR;
141 vector = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
142
143 bus_space_write_2(sc->sc_iot, sc->sc_ioh, offset, vector);
144 ret = bus_space_read_2(sc->sc_iot, sc->sc_ioh, offset);
145 aprint_debug_dev(sc->sc_dev, "expected=%d, actual=%d\n",
146 vector, ret);
147 if (ret != vector)
148 return -1;
149 }
150
151 return 0;
152 }
153
154 static int
155 virtio_setup_msix_interrupts(struct virtio_softc *sc,
156 struct pci_attach_args *pa)
157 {
158 device_t self = sc->sc_dev;
159 pci_chipset_tag_t pc = pa->pa_pc;
160 char intrbuf[PCI_INTRSTR_LEN];
161 char const *intrstr;
162 int idx;
163
164 idx = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
165 if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
166 pci_intr_setattr(pc, &sc->sc_ihp[idx], PCI_INTR_MPSAFE, true);
167
168 sc->sc_ihs[idx] = pci_intr_establish_xname(pc, sc->sc_ihp[idx], IPL_NET,
169 virtio_msix_config_intr, sc, device_xname(sc->sc_dev));
170 if (sc->sc_ihs[idx] == NULL) {
171 aprint_error_dev(self, "couldn't establish MSI-X for config\n");
172 goto error;
173 }
174
175 idx = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
176 if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
177 pci_intr_setattr(pc, &sc->sc_ihp[idx], PCI_INTR_MPSAFE, true);
178
179 sc->sc_ihs[idx] = pci_intr_establish_xname(pc, sc->sc_ihp[idx], IPL_NET,
180 virtio_msix_queue_intr, sc, device_xname(sc->sc_dev));
181 if (sc->sc_ihs[idx] == NULL) {
182 aprint_error_dev(self, "couldn't establish MSI-X for queues\n");
183 goto error;
184 }
185
186 if (virtio_setup_msix_vectors(sc) != 0) {
187 aprint_error_dev(self, "couldn't setup MSI-X vectors\n");
188 goto error;
189 }
190
191 idx = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
192 intrstr = pci_intr_string(pc, sc->sc_ihp[idx], intrbuf, sizeof(intrbuf));
193 aprint_normal_dev(self, "config interrupting at %s\n", intrstr);
194 idx = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
195 intrstr = pci_intr_string(pc, sc->sc_ihp[idx], intrbuf, sizeof(intrbuf));
196 aprint_normal_dev(self, "queues interrupting at %s\n", intrstr);
197
198 return 0;
199
200 error:
201 idx = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
202 if (sc->sc_ihs[idx] != NULL)
203 pci_intr_disestablish(sc->sc_pc, sc->sc_ihs[idx]);
204 idx = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
205 if (sc->sc_ihs[idx] != NULL)
206 pci_intr_disestablish(sc->sc_pc, sc->sc_ihs[idx]);
207
208 return -1;
209 }
210
211 static int
212 virtio_setup_intx_interrupt(struct virtio_softc *sc,
213 struct pci_attach_args *pa)
214 {
215 device_t self = sc->sc_dev;
216 pci_chipset_tag_t pc = pa->pa_pc;
217 char intrbuf[PCI_INTRSTR_LEN];
218 char const *intrstr;
219
220 if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
221 pci_intr_setattr(pc, &sc->sc_ihp[0], PCI_INTR_MPSAFE, true);
222
223 sc->sc_ihs[0] = pci_intr_establish_xname(pc, sc->sc_ihp[0],
224 IPL_NET, virtio_intr, sc, device_xname(sc->sc_dev));
225 if (sc->sc_ihs[0] == NULL) {
226 aprint_error_dev(self, "couldn't establish INTx\n");
227 return -1;
228 }
229
230 intrstr = pci_intr_string(pc, sc->sc_ihp[0], intrbuf, sizeof(intrbuf));
231 aprint_normal_dev(self, "interrupting at %s\n", intrstr);
232
233 return 0;
234 }
235
236 static int
237 virtio_setup_interrupts(struct virtio_softc *sc)
238 {
239 device_t self = sc->sc_dev;
240 pci_chipset_tag_t pc = sc->sc_pa.pa_pc;
241 int error;
242 int nmsix;
243 int counts[PCI_INTR_TYPE_SIZE];
244 pci_intr_type_t max_type;
245
246 nmsix = pci_msix_count(sc->sc_pa.pa_pc, sc->sc_pa.pa_tag);
247 aprint_debug_dev(self, "pci_msix_count=%d\n", nmsix);
248
249 /* We need at least two: one for config and the other for queues */
250 if ((sc->sc_flags & VIRTIO_F_PCI_INTR_MSIX) == 0 || nmsix < 2) {
251 /* Try INTx only */
252 max_type = PCI_INTR_TYPE_INTX;
253 counts[PCI_INTR_TYPE_INTX] = 1;
254 } else {
255 /* Try MSI-X first and INTx second */
256 max_type = PCI_INTR_TYPE_MSIX;
257 counts[PCI_INTR_TYPE_MSIX] = 2;
258 counts[PCI_INTR_TYPE_MSI] = 0;
259 counts[PCI_INTR_TYPE_INTX] = 1;
260 }
261
262 retry:
263 error = pci_intr_alloc(&sc->sc_pa, &sc->sc_ihp, counts, max_type);
264 if (error != 0) {
265 aprint_error_dev(self, "couldn't map interrupt\n");
266 return -1;
267 }
268
269 if (pci_intr_type(pc, sc->sc_ihp[0]) == PCI_INTR_TYPE_MSIX) {
270 sc->sc_ihs = kmem_alloc(sizeof(*sc->sc_ihs) * 2,
271 KM_SLEEP);
272 if (sc->sc_ihs == NULL) {
273 pci_intr_release(pc, sc->sc_ihp, 2);
274
275 /* Retry INTx */
276 max_type = PCI_INTR_TYPE_INTX;
277 counts[PCI_INTR_TYPE_INTX] = 1;
278 goto retry;
279 }
280
281 error = virtio_setup_msix_interrupts(sc, &sc->sc_pa);
282 if (error != 0) {
283 kmem_free(sc->sc_ihs, sizeof(*sc->sc_ihs) * 2);
284 pci_intr_release(pc, sc->sc_ihp, 2);
285
286 /* Retry INTx */
287 max_type = PCI_INTR_TYPE_INTX;
288 counts[PCI_INTR_TYPE_INTX] = 1;
289 goto retry;
290 }
291
292 sc->sc_ihs_num = 2;
293 sc->sc_config_offset = VIRTIO_CONFIG_DEVICE_CONFIG_MSI;
294 } else if (pci_intr_type(pc, sc->sc_ihp[0]) == PCI_INTR_TYPE_INTX) {
295 sc->sc_ihs = kmem_alloc(sizeof(*sc->sc_ihs) * 1,
296 KM_SLEEP);
297 if (sc->sc_ihs == NULL) {
298 pci_intr_release(pc, sc->sc_ihp, 1);
299 return -1;
300 }
301
302 error = virtio_setup_intx_interrupt(sc, &sc->sc_pa);
303 if (error != 0) {
304 kmem_free(sc->sc_ihs, sizeof(*sc->sc_ihs) * 1);
305 pci_intr_release(pc, sc->sc_ihp, 1);
306 return -1;
307 }
308
309 sc->sc_ihs_num = 1;
310 sc->sc_config_offset = VIRTIO_CONFIG_DEVICE_CONFIG_NOMSI;
311 }
312
313 return 0;
314 }
315
316 static void
317 virtio_attach(device_t parent, device_t self, void *aux)
318 {
319 struct virtio_softc *sc = device_private(self);
320 struct pci_attach_args *pa = (struct pci_attach_args *)aux;
321 pci_chipset_tag_t pc = pa->pa_pc;
322 pcitag_t tag = pa->pa_tag;
323 int revision;
324 pcireg_t id;
325
326 revision = PCI_REVISION(pa->pa_class);
327 if (revision != 0) {
328 aprint_normal(": unknown revision 0x%02x; giving up\n",
329 revision);
330 return;
331 }
332 aprint_normal("\n");
333 aprint_naive("\n");
334
335 /* subsystem ID shows what I am */
336 id = pci_conf_read(pc, tag, PCI_SUBSYS_ID_REG);
337 aprint_normal_dev(self, "Virtio %s Device (rev. 0x%02x)\n",
338 (PCI_SUBSYS_ID(id) < NDEVNAMES?
339 virtio_device_name[PCI_SUBSYS_ID(id)] : "Unknown"),
340 revision);
341
342 sc->sc_dev = self;
343 sc->sc_pc = pc;
344 sc->sc_tag = tag;
345 sc->sc_iot = pa->pa_iot;
346 if (pci_dma64_available(pa))
347 sc->sc_dmat = pa->pa_dmat64;
348 else
349 sc->sc_dmat = pa->pa_dmat;
350 sc->sc_config_offset = VIRTIO_CONFIG_DEVICE_CONFIG_NOMSI;
351
352 if (pci_mapreg_map(pa, PCI_MAPREG_START, PCI_MAPREG_TYPE_IO, 0,
353 &sc->sc_iot, &sc->sc_ioh, NULL, &sc->sc_iosize)) {
354 aprint_error_dev(self, "can't map i/o space\n");
355 return;
356 }
357
358 virtio_device_reset(sc);
359 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_ACK);
360 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER);
361
362 /* XXX: use softc as aux... */
363 sc->sc_childdevid = PCI_SUBSYS_ID(id);
364 sc->sc_child = NULL;
365 sc->sc_pa = *pa;
366 virtio_rescan(self, "virtio", 0);
367 return;
368 }
369
370 /* ARGSUSED */
371 static int
372 virtio_rescan(device_t self, const char *attr, const int *scan_flags)
373 {
374 struct virtio_softc *sc;
375 int r;
376
377 sc = device_private(self);
378 if (sc->sc_child) /* Child already attached? */
379 return 0;
380 config_found_ia(self, attr, sc, NULL);
381 if (sc->sc_child == NULL) {
382 aprint_error_dev(self,
383 "no matching child driver; not configured\n");
384 return 0;
385 }
386 if (sc->sc_child == (void*)1) { /* this shows error */
387 aprint_error_dev(self,
388 "virtio configuration failed\n");
389 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_FAILED);
390 return 0;
391 }
392
393 r = virtio_setup_interrupts(sc);
394 if (r != 0) {
395 aprint_error_dev(self, "failed to setup interrupts\n");
396 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_FAILED);
397 return 0;
398 }
399
400 sc->sc_soft_ih = NULL;
401 if (sc->sc_flags & VIRTIO_F_PCI_INTR_SOFTINT) {
402 u_int flags = SOFTINT_NET;
403 if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
404 flags |= SOFTINT_MPSAFE;
405
406 sc->sc_soft_ih = softint_establish(flags, virtio_soft_intr, sc);
407 if (sc->sc_soft_ih == NULL)
408 aprint_error(": failed to establish soft interrupt\n");
409 }
410
411 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER_OK);
412
413 return 0;
414 }
415
416 static int
417 virtio_detach(device_t self, int flags)
418 {
419 struct virtio_softc *sc = device_private(self);
420 int r;
421 int i;
422
423 if (sc->sc_child != 0 && sc->sc_child != (void*)1) {
424 r = config_detach(sc->sc_child, flags);
425 if (r)
426 return r;
427 }
428 KASSERT(sc->sc_child == 0 || sc->sc_child == (void*)1);
429 KASSERT(sc->sc_vqs == 0);
430 for (i = 0; i < sc->sc_ihs_num; i++) {
431 if (sc->sc_ihs[i] == NULL)
432 continue;
433 pci_intr_disestablish(sc->sc_pc, sc->sc_ihs[i]);
434 }
435 pci_intr_release(sc->sc_pc, sc->sc_ihp, sc->sc_ihs_num);
436 kmem_free(sc->sc_ihs, sizeof(*sc->sc_ihs) * sc->sc_ihs_num);
437 sc->sc_ihs_num = 0;
438 if (sc->sc_iosize)
439 bus_space_unmap(sc->sc_iot, sc->sc_ioh, sc->sc_iosize);
440 sc->sc_iosize = 0;
441
442 return 0;
443 }
444
445 /*
446 * Reset the device.
447 */
448 /*
449 * To reset the device to a known state, do following:
450 * virtio_reset(sc); // this will stop the device activity
451 * <dequeue finished requests>; // virtio_dequeue() still can be called
452 * <revoke pending requests in the vqs if any>;
453 * virtio_reinit_begin(sc); // dequeue prohibitted
454 * newfeatures = virtio_negotiate_features(sc, requestedfeatures);
455 * <some other initialization>;
456 * virtio_reinit_end(sc); // device activated; enqueue allowed
457 * Once attached, feature negotiation can only be allowed after virtio_reset.
458 */
459 void
460 virtio_reset(struct virtio_softc *sc)
461 {
462 virtio_device_reset(sc);
463 }
464
465 void
466 virtio_reinit_start(struct virtio_softc *sc)
467 {
468 int i;
469
470 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_ACK);
471 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER);
472 for (i = 0; i < sc->sc_nvqs; i++) {
473 int n;
474 struct virtqueue *vq = &sc->sc_vqs[i];
475 bus_space_write_2(sc->sc_iot, sc->sc_ioh,
476 VIRTIO_CONFIG_QUEUE_SELECT,
477 vq->vq_index);
478 n = bus_space_read_2(sc->sc_iot, sc->sc_ioh,
479 VIRTIO_CONFIG_QUEUE_SIZE);
480 if (n == 0) /* vq disappeared */
481 continue;
482 if (n != vq->vq_num) {
483 panic("%s: virtqueue size changed, vq index %d\n",
484 device_xname(sc->sc_dev),
485 vq->vq_index);
486 }
487 virtio_init_vq(sc, vq, true);
488 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
489 VIRTIO_CONFIG_QUEUE_ADDRESS,
490 (vq->vq_dmamap->dm_segs[0].ds_addr
491 / VIRTIO_PAGE_SIZE));
492 }
493
494 /* MSI-X should have more than one handles where INTx has just one */
495 if (sc->sc_ihs_num > 1) {
496 if (virtio_setup_msix_vectors(sc) != 0) {
497 aprint_error_dev(sc->sc_dev,
498 "couldn't setup MSI-X vectors\n");
499 return;
500 }
501 }
502 }
503
504 void
505 virtio_reinit_end(struct virtio_softc *sc)
506 {
507 virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER_OK);
508 }
509
510 /*
511 * Feature negotiation.
512 */
513 uint32_t
514 virtio_negotiate_features(struct virtio_softc *sc, uint32_t guest_features)
515 {
516 uint32_t r;
517
518 if (!(device_cfdata(sc->sc_dev)->cf_flags & 1) &&
519 !(device_cfdata(sc->sc_child)->cf_flags & 1)) /* XXX */
520 guest_features |= VIRTIO_F_RING_INDIRECT_DESC;
521 r = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
522 VIRTIO_CONFIG_DEVICE_FEATURES);
523 r &= guest_features;
524 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
525 VIRTIO_CONFIG_GUEST_FEATURES, r);
526 sc->sc_features = r;
527 if (r & VIRTIO_F_RING_INDIRECT_DESC)
528 sc->sc_indirect = true;
529 else
530 sc->sc_indirect = false;
531
532 return r;
533 }
534
535 /*
536 * Device configuration registers.
537 */
538 uint8_t
539 virtio_read_device_config_1(struct virtio_softc *sc, int index)
540 {
541 return bus_space_read_1(sc->sc_iot, sc->sc_ioh,
542 sc->sc_config_offset + index);
543 }
544
545 uint16_t
546 virtio_read_device_config_2(struct virtio_softc *sc, int index)
547 {
548 return bus_space_read_2(sc->sc_iot, sc->sc_ioh,
549 sc->sc_config_offset + index);
550 }
551
552 uint32_t
553 virtio_read_device_config_4(struct virtio_softc *sc, int index)
554 {
555 return bus_space_read_4(sc->sc_iot, sc->sc_ioh,
556 sc->sc_config_offset + index);
557 }
558
559 uint64_t
560 virtio_read_device_config_8(struct virtio_softc *sc, int index)
561 {
562 uint64_t r;
563
564 r = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
565 sc->sc_config_offset + index + sizeof(uint32_t));
566 r <<= 32;
567 r += bus_space_read_4(sc->sc_iot, sc->sc_ioh,
568 sc->sc_config_offset + index);
569 return r;
570 }
571
572 void
573 virtio_write_device_config_1(struct virtio_softc *sc,
574 int index, uint8_t value)
575 {
576 bus_space_write_1(sc->sc_iot, sc->sc_ioh,
577 sc->sc_config_offset + index, value);
578 }
579
580 void
581 virtio_write_device_config_2(struct virtio_softc *sc,
582 int index, uint16_t value)
583 {
584 bus_space_write_2(sc->sc_iot, sc->sc_ioh,
585 sc->sc_config_offset + index, value);
586 }
587
588 void
589 virtio_write_device_config_4(struct virtio_softc *sc,
590 int index, uint32_t value)
591 {
592 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
593 sc->sc_config_offset + index, value);
594 }
595
596 void
597 virtio_write_device_config_8(struct virtio_softc *sc,
598 int index, uint64_t value)
599 {
600 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
601 sc->sc_config_offset + index,
602 value & 0xffffffff);
603 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
604 sc->sc_config_offset + index + sizeof(uint32_t),
605 value >> 32);
606 }
607
608 /*
609 * Interrupt handler.
610 */
611 static int
612 virtio_intr(void *arg)
613 {
614 struct virtio_softc *sc = arg;
615 int isr, r = 0;
616
617 /* check and ack the interrupt */
618 isr = bus_space_read_1(sc->sc_iot, sc->sc_ioh,
619 VIRTIO_CONFIG_ISR_STATUS);
620 if (isr == 0)
621 return 0;
622 if ((isr & VIRTIO_CONFIG_ISR_CONFIG_CHANGE) &&
623 (sc->sc_config_change != NULL))
624 r = (sc->sc_config_change)(sc);
625 if (sc->sc_intrhand != NULL) {
626 if (sc->sc_soft_ih != NULL)
627 softint_schedule(sc->sc_soft_ih);
628 else
629 r |= (sc->sc_intrhand)(sc);
630 }
631
632 return r;
633 }
634
635 static int
636 virtio_msix_queue_intr(void *arg)
637 {
638 struct virtio_softc *sc = arg;
639 int r = 0;
640
641 if (sc->sc_intrhand != NULL) {
642 if (sc->sc_soft_ih != NULL)
643 softint_schedule(sc->sc_soft_ih);
644 else
645 r |= (sc->sc_intrhand)(sc);
646 }
647
648 return r;
649 }
650
651 static int
652 virtio_msix_config_intr(void *arg)
653 {
654 struct virtio_softc *sc = arg;
655
656 /* TODO: handle events */
657 aprint_debug_dev(sc->sc_dev, "%s\n", __func__);
658 return 1;
659 }
660
661 static void
662 virtio_soft_intr(void *arg)
663 {
664 struct virtio_softc *sc = arg;
665
666 KASSERT(sc->sc_intrhand != NULL);
667
668 (sc->sc_intrhand)(sc);
669 }
670
671 /*
672 * dmamap sync operations for a virtqueue.
673 */
674 static inline void
675 vq_sync_descs(struct virtio_softc *sc, struct virtqueue *vq, int ops)
676 {
677 /* availoffset == sizeof(vring_desc)*vq_num */
678 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap, 0, vq->vq_availoffset,
679 ops);
680 }
681
682 static inline void
683 vq_sync_aring(struct virtio_softc *sc, struct virtqueue *vq, int ops)
684 {
685 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap,
686 vq->vq_availoffset,
687 offsetof(struct vring_avail, ring)
688 + vq->vq_num * sizeof(uint16_t),
689 ops);
690 }
691
692 static inline void
693 vq_sync_uring(struct virtio_softc *sc, struct virtqueue *vq, int ops)
694 {
695 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap,
696 vq->vq_usedoffset,
697 offsetof(struct vring_used, ring)
698 + vq->vq_num * sizeof(struct vring_used_elem),
699 ops);
700 }
701
702 static inline void
703 vq_sync_indirect(struct virtio_softc *sc, struct virtqueue *vq, int slot,
704 int ops)
705 {
706 int offset = vq->vq_indirectoffset
707 + sizeof(struct vring_desc) * vq->vq_maxnsegs * slot;
708
709 bus_dmamap_sync(sc->sc_dmat, vq->vq_dmamap,
710 offset, sizeof(struct vring_desc) * vq->vq_maxnsegs,
711 ops);
712 }
713
714 /*
715 * Can be used as sc_intrhand.
716 */
717 /*
718 * Scan vq, bus_dmamap_sync for the vqs (not for the payload),
719 * and calls (*vq_done)() if some entries are consumed.
720 */
721 int
722 virtio_vq_intr(struct virtio_softc *sc)
723 {
724 struct virtqueue *vq;
725 int i, r = 0;
726
727 for (i = 0; i < sc->sc_nvqs; i++) {
728 vq = &sc->sc_vqs[i];
729 if (vq->vq_queued) {
730 vq->vq_queued = 0;
731 vq_sync_aring(sc, vq, BUS_DMASYNC_POSTWRITE);
732 }
733 vq_sync_uring(sc, vq, BUS_DMASYNC_POSTREAD);
734 membar_consumer();
735 if (vq->vq_used_idx != vq->vq_used->idx) {
736 if (vq->vq_done)
737 r |= (vq->vq_done)(vq);
738 }
739 }
740
741 return r;
742 }
743
744 /*
745 * Start/stop vq interrupt. No guarantee.
746 */
747 void
748 virtio_stop_vq_intr(struct virtio_softc *sc, struct virtqueue *vq)
749 {
750 vq->vq_avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
751 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE);
752 vq->vq_queued++;
753 }
754
755 void
756 virtio_start_vq_intr(struct virtio_softc *sc, struct virtqueue *vq)
757 {
758 vq->vq_avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
759 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE);
760 vq->vq_queued++;
761 }
762
763 /*
764 * Initialize vq structure.
765 */
766 static void
767 virtio_init_vq(struct virtio_softc *sc, struct virtqueue *vq,
768 const bool reinit)
769 {
770 int i, j;
771 int vq_size = vq->vq_num;
772
773 memset(vq->vq_vaddr, 0, vq->vq_bytesize);
774
775 /* build the indirect descriptor chain */
776 if (vq->vq_indirect != NULL) {
777 struct vring_desc *vd;
778
779 for (i = 0; i < vq_size; i++) {
780 vd = vq->vq_indirect;
781 vd += vq->vq_maxnsegs * i;
782 for (j = 0; j < vq->vq_maxnsegs-1; j++)
783 vd[j].next = j + 1;
784 }
785 }
786
787 /* free slot management */
788 SIMPLEQ_INIT(&vq->vq_freelist);
789 for (i = 0; i < vq_size; i++) {
790 SIMPLEQ_INSERT_TAIL(&vq->vq_freelist,
791 &vq->vq_entries[i], qe_list);
792 vq->vq_entries[i].qe_index = i;
793 }
794 if (!reinit)
795 mutex_init(&vq->vq_freelist_lock, MUTEX_SPIN, sc->sc_ipl);
796
797 /* enqueue/dequeue status */
798 vq->vq_avail_idx = 0;
799 vq->vq_used_idx = 0;
800 vq->vq_queued = 0;
801 if (!reinit) {
802 mutex_init(&vq->vq_aring_lock, MUTEX_SPIN, sc->sc_ipl);
803 mutex_init(&vq->vq_uring_lock, MUTEX_SPIN, sc->sc_ipl);
804 }
805 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE);
806 vq_sync_uring(sc, vq, BUS_DMASYNC_PREREAD);
807 vq->vq_queued++;
808 }
809
810 /*
811 * Allocate/free a vq.
812 */
813 int
814 virtio_alloc_vq(struct virtio_softc *sc, struct virtqueue *vq, int index,
815 int maxsegsize, int maxnsegs, const char *name)
816 {
817 int vq_size, allocsize1, allocsize2, allocsize3, allocsize = 0;
818 int rsegs, r;
819 #define VIRTQUEUE_ALIGN(n) (((n)+(VIRTIO_PAGE_SIZE-1))& \
820 ~(VIRTIO_PAGE_SIZE-1))
821
822 memset(vq, 0, sizeof(*vq));
823
824 bus_space_write_2(sc->sc_iot, sc->sc_ioh,
825 VIRTIO_CONFIG_QUEUE_SELECT, index);
826 vq_size = bus_space_read_2(sc->sc_iot, sc->sc_ioh,
827 VIRTIO_CONFIG_QUEUE_SIZE);
828 if (vq_size == 0) {
829 aprint_error_dev(sc->sc_dev,
830 "virtqueue not exist, index %d for %s\n",
831 index, name);
832 goto err;
833 }
834 /* allocsize1: descriptor table + avail ring + pad */
835 allocsize1 = VIRTQUEUE_ALIGN(sizeof(struct vring_desc)*vq_size
836 + sizeof(uint16_t)*(2+vq_size));
837 /* allocsize2: used ring + pad */
838 allocsize2 = VIRTQUEUE_ALIGN(sizeof(uint16_t)*2
839 + sizeof(struct vring_used_elem)*vq_size);
840 /* allocsize3: indirect table */
841 if (sc->sc_indirect && maxnsegs >= MINSEG_INDIRECT)
842 allocsize3 = sizeof(struct vring_desc) * maxnsegs * vq_size;
843 else
844 allocsize3 = 0;
845 allocsize = allocsize1 + allocsize2 + allocsize3;
846
847 /* alloc and map the memory */
848 r = bus_dmamem_alloc(sc->sc_dmat, allocsize, VIRTIO_PAGE_SIZE, 0,
849 &vq->vq_segs[0], 1, &rsegs, BUS_DMA_NOWAIT);
850 if (r != 0) {
851 aprint_error_dev(sc->sc_dev,
852 "virtqueue %d for %s allocation failed, "
853 "error code %d\n", index, name, r);
854 goto err;
855 }
856 r = bus_dmamem_map(sc->sc_dmat, &vq->vq_segs[0], 1, allocsize,
857 &vq->vq_vaddr, BUS_DMA_NOWAIT);
858 if (r != 0) {
859 aprint_error_dev(sc->sc_dev,
860 "virtqueue %d for %s map failed, "
861 "error code %d\n", index, name, r);
862 goto err;
863 }
864 r = bus_dmamap_create(sc->sc_dmat, allocsize, 1, allocsize, 0,
865 BUS_DMA_NOWAIT, &vq->vq_dmamap);
866 if (r != 0) {
867 aprint_error_dev(sc->sc_dev,
868 "virtqueue %d for %s dmamap creation failed, "
869 "error code %d\n", index, name, r);
870 goto err;
871 }
872 r = bus_dmamap_load(sc->sc_dmat, vq->vq_dmamap,
873 vq->vq_vaddr, allocsize, NULL, BUS_DMA_NOWAIT);
874 if (r != 0) {
875 aprint_error_dev(sc->sc_dev,
876 "virtqueue %d for %s dmamap load failed, "
877 "error code %d\n", index, name, r);
878 goto err;
879 }
880
881 /* set the vq address */
882 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
883 VIRTIO_CONFIG_QUEUE_ADDRESS,
884 (vq->vq_dmamap->dm_segs[0].ds_addr
885 / VIRTIO_PAGE_SIZE));
886
887 /* remember addresses and offsets for later use */
888 vq->vq_owner = sc;
889 vq->vq_num = vq_size;
890 vq->vq_index = index;
891 vq->vq_desc = vq->vq_vaddr;
892 vq->vq_availoffset = sizeof(struct vring_desc)*vq_size;
893 vq->vq_avail = (void*)(((char*)vq->vq_desc) + vq->vq_availoffset);
894 vq->vq_usedoffset = allocsize1;
895 vq->vq_used = (void*)(((char*)vq->vq_desc) + vq->vq_usedoffset);
896 if (allocsize3 > 0) {
897 vq->vq_indirectoffset = allocsize1 + allocsize2;
898 vq->vq_indirect = (void*)(((char*)vq->vq_desc)
899 + vq->vq_indirectoffset);
900 }
901 vq->vq_bytesize = allocsize;
902 vq->vq_maxsegsize = maxsegsize;
903 vq->vq_maxnsegs = maxnsegs;
904
905 /* free slot management */
906 vq->vq_entries = kmem_zalloc(sizeof(struct vq_entry)*vq_size,
907 KM_NOSLEEP);
908 if (vq->vq_entries == NULL) {
909 r = ENOMEM;
910 goto err;
911 }
912
913 virtio_init_vq(sc, vq, false);
914
915 aprint_verbose_dev(sc->sc_dev,
916 "allocated %u byte for virtqueue %d for %s, "
917 "size %d\n", allocsize, index, name, vq_size);
918 if (allocsize3 > 0)
919 aprint_verbose_dev(sc->sc_dev,
920 "using %d byte (%d entries) "
921 "indirect descriptors\n",
922 allocsize3, maxnsegs * vq_size);
923 return 0;
924
925 err:
926 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
927 VIRTIO_CONFIG_QUEUE_ADDRESS, 0);
928 if (vq->vq_dmamap)
929 bus_dmamap_destroy(sc->sc_dmat, vq->vq_dmamap);
930 if (vq->vq_vaddr)
931 bus_dmamem_unmap(sc->sc_dmat, vq->vq_vaddr, allocsize);
932 if (vq->vq_segs[0].ds_addr)
933 bus_dmamem_free(sc->sc_dmat, &vq->vq_segs[0], 1);
934 memset(vq, 0, sizeof(*vq));
935
936 return -1;
937 }
938
939 int
940 virtio_free_vq(struct virtio_softc *sc, struct virtqueue *vq)
941 {
942 struct vq_entry *qe;
943 int i = 0;
944
945 /* device must be already deactivated */
946 /* confirm the vq is empty */
947 SIMPLEQ_FOREACH(qe, &vq->vq_freelist, qe_list) {
948 i++;
949 }
950 if (i != vq->vq_num) {
951 printf("%s: freeing non-empty vq, index %d\n",
952 device_xname(sc->sc_dev), vq->vq_index);
953 return EBUSY;
954 }
955
956 /* tell device that there's no virtqueue any longer */
957 bus_space_write_2(sc->sc_iot, sc->sc_ioh,
958 VIRTIO_CONFIG_QUEUE_SELECT, vq->vq_index);
959 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
960 VIRTIO_CONFIG_QUEUE_ADDRESS, 0);
961
962 kmem_free(vq->vq_entries, sizeof(*vq->vq_entries) * vq->vq_num);
963 bus_dmamap_unload(sc->sc_dmat, vq->vq_dmamap);
964 bus_dmamap_destroy(sc->sc_dmat, vq->vq_dmamap);
965 bus_dmamem_unmap(sc->sc_dmat, vq->vq_vaddr, vq->vq_bytesize);
966 bus_dmamem_free(sc->sc_dmat, &vq->vq_segs[0], 1);
967 mutex_destroy(&vq->vq_freelist_lock);
968 mutex_destroy(&vq->vq_uring_lock);
969 mutex_destroy(&vq->vq_aring_lock);
970 memset(vq, 0, sizeof(*vq));
971
972 return 0;
973 }
974
975 /*
976 * Free descriptor management.
977 */
978 static struct vq_entry *
979 vq_alloc_entry(struct virtqueue *vq)
980 {
981 struct vq_entry *qe;
982
983 mutex_enter(&vq->vq_freelist_lock);
984 if (SIMPLEQ_EMPTY(&vq->vq_freelist)) {
985 mutex_exit(&vq->vq_freelist_lock);
986 return NULL;
987 }
988 qe = SIMPLEQ_FIRST(&vq->vq_freelist);
989 SIMPLEQ_REMOVE_HEAD(&vq->vq_freelist, qe_list);
990 mutex_exit(&vq->vq_freelist_lock);
991
992 return qe;
993 }
994
995 static void
996 vq_free_entry(struct virtqueue *vq, struct vq_entry *qe)
997 {
998 mutex_enter(&vq->vq_freelist_lock);
999 SIMPLEQ_INSERT_TAIL(&vq->vq_freelist, qe, qe_list);
1000 mutex_exit(&vq->vq_freelist_lock);
1001
1002 return;
1003 }
1004
1005 /*
1006 * Enqueue several dmamaps as a single request.
1007 */
1008 /*
1009 * Typical usage:
1010 * <queue size> number of followings are stored in arrays
1011 * - command blocks (in dmamem) should be pre-allocated and mapped
1012 * - dmamaps for command blocks should be pre-allocated and loaded
1013 * - dmamaps for payload should be pre-allocated
1014 * r = virtio_enqueue_prep(sc, vq, &slot); // allocate a slot
1015 * if (r) // currently 0 or EAGAIN
1016 * return r;
1017 * r = bus_dmamap_load(dmat, dmamap_payload[slot], data, count, ..);
1018 * if (r) {
1019 * virtio_enqueue_abort(sc, vq, slot);
1020 * bus_dmamap_unload(dmat, dmamap_payload[slot]);
1021 * return r;
1022 * }
1023 * r = virtio_enqueue_reserve(sc, vq, slot,
1024 * dmamap_payload[slot]->dm_nsegs+1);
1025 * // ^ +1 for command
1026 * if (r) { // currently 0 or EAGAIN
1027 * bus_dmamap_unload(dmat, dmamap_payload[slot]);
1028 * return r; // do not call abort()
1029 * }
1030 * <setup and prepare commands>
1031 * bus_dmamap_sync(dmat, dmamap_cmd[slot],... BUS_DMASYNC_PREWRITE);
1032 * bus_dmamap_sync(dmat, dmamap_payload[slot],...);
1033 * virtio_enqueue(sc, vq, slot, dmamap_cmd[slot], false);
1034 * virtio_enqueue(sc, vq, slot, dmamap_payload[slot], iswrite);
1035 * virtio_enqueue_commit(sc, vq, slot, true);
1036 */
1037
1038 /*
1039 * enqueue_prep: allocate a slot number
1040 */
1041 int
1042 virtio_enqueue_prep(struct virtio_softc *sc, struct virtqueue *vq, int *slotp)
1043 {
1044 struct vq_entry *qe1;
1045
1046 KASSERT(slotp != NULL);
1047
1048 qe1 = vq_alloc_entry(vq);
1049 if (qe1 == NULL)
1050 return EAGAIN;
1051 /* next slot is not allocated yet */
1052 qe1->qe_next = -1;
1053 *slotp = qe1->qe_index;
1054
1055 return 0;
1056 }
1057
1058 /*
1059 * enqueue_reserve: allocate remaining slots and build the descriptor chain.
1060 */
1061 int
1062 virtio_enqueue_reserve(struct virtio_softc *sc, struct virtqueue *vq,
1063 int slot, int nsegs)
1064 {
1065 int indirect;
1066 struct vq_entry *qe1 = &vq->vq_entries[slot];
1067
1068 KASSERT(qe1->qe_next == -1);
1069 KASSERT(1 <= nsegs && nsegs <= vq->vq_num);
1070
1071 if ((vq->vq_indirect != NULL) &&
1072 (nsegs >= MINSEG_INDIRECT) &&
1073 (nsegs <= vq->vq_maxnsegs))
1074 indirect = 1;
1075 else
1076 indirect = 0;
1077 qe1->qe_indirect = indirect;
1078
1079 if (indirect) {
1080 struct vring_desc *vd;
1081 int i;
1082
1083 vd = &vq->vq_desc[qe1->qe_index];
1084 vd->addr = vq->vq_dmamap->dm_segs[0].ds_addr
1085 + vq->vq_indirectoffset;
1086 vd->addr += sizeof(struct vring_desc)
1087 * vq->vq_maxnsegs * qe1->qe_index;
1088 vd->len = sizeof(struct vring_desc) * nsegs;
1089 vd->flags = VRING_DESC_F_INDIRECT;
1090
1091 vd = vq->vq_indirect;
1092 vd += vq->vq_maxnsegs * qe1->qe_index;
1093 qe1->qe_desc_base = vd;
1094
1095 for (i = 0; i < nsegs-1; i++) {
1096 vd[i].flags = VRING_DESC_F_NEXT;
1097 }
1098 vd[i].flags = 0;
1099 qe1->qe_next = 0;
1100
1101 return 0;
1102 } else {
1103 struct vring_desc *vd;
1104 struct vq_entry *qe;
1105 int i, s;
1106
1107 vd = &vq->vq_desc[0];
1108 qe1->qe_desc_base = vd;
1109 qe1->qe_next = qe1->qe_index;
1110 s = slot;
1111 for (i = 0; i < nsegs - 1; i++) {
1112 qe = vq_alloc_entry(vq);
1113 if (qe == NULL) {
1114 vd[s].flags = 0;
1115 virtio_enqueue_abort(sc, vq, slot);
1116 return EAGAIN;
1117 }
1118 vd[s].flags = VRING_DESC_F_NEXT;
1119 vd[s].next = qe->qe_index;
1120 s = qe->qe_index;
1121 }
1122 vd[s].flags = 0;
1123
1124 return 0;
1125 }
1126 }
1127
1128 /*
1129 * enqueue: enqueue a single dmamap.
1130 */
1131 int
1132 virtio_enqueue(struct virtio_softc *sc, struct virtqueue *vq, int slot,
1133 bus_dmamap_t dmamap, bool write)
1134 {
1135 struct vq_entry *qe1 = &vq->vq_entries[slot];
1136 struct vring_desc *vd = qe1->qe_desc_base;
1137 int i;
1138 int s = qe1->qe_next;
1139
1140 KASSERT(s >= 0);
1141 KASSERT(dmamap->dm_nsegs > 0);
1142
1143 for (i = 0; i < dmamap->dm_nsegs; i++) {
1144 vd[s].addr = dmamap->dm_segs[i].ds_addr;
1145 vd[s].len = dmamap->dm_segs[i].ds_len;
1146 if (!write)
1147 vd[s].flags |= VRING_DESC_F_WRITE;
1148 s = vd[s].next;
1149 }
1150 qe1->qe_next = s;
1151
1152 return 0;
1153 }
1154
1155 int
1156 virtio_enqueue_p(struct virtio_softc *sc, struct virtqueue *vq, int slot,
1157 bus_dmamap_t dmamap, bus_addr_t start, bus_size_t len,
1158 bool write)
1159 {
1160 struct vq_entry *qe1 = &vq->vq_entries[slot];
1161 struct vring_desc *vd = qe1->qe_desc_base;
1162 int s = qe1->qe_next;
1163
1164 KASSERT(s >= 0);
1165 KASSERT(dmamap->dm_nsegs == 1); /* XXX */
1166 KASSERT((dmamap->dm_segs[0].ds_len > start) &&
1167 (dmamap->dm_segs[0].ds_len >= start + len));
1168
1169 vd[s].addr = dmamap->dm_segs[0].ds_addr + start;
1170 vd[s].len = len;
1171 if (!write)
1172 vd[s].flags |= VRING_DESC_F_WRITE;
1173 qe1->qe_next = vd[s].next;
1174
1175 return 0;
1176 }
1177
1178 /*
1179 * enqueue_commit: add it to the aring.
1180 */
1181 int
1182 virtio_enqueue_commit(struct virtio_softc *sc, struct virtqueue *vq, int slot,
1183 bool notifynow)
1184 {
1185 struct vq_entry *qe1;
1186
1187 if (slot < 0) {
1188 mutex_enter(&vq->vq_aring_lock);
1189 goto notify;
1190 }
1191 vq_sync_descs(sc, vq, BUS_DMASYNC_PREWRITE);
1192 qe1 = &vq->vq_entries[slot];
1193 if (qe1->qe_indirect)
1194 vq_sync_indirect(sc, vq, slot, BUS_DMASYNC_PREWRITE);
1195 mutex_enter(&vq->vq_aring_lock);
1196 vq->vq_avail->ring[(vq->vq_avail_idx++) % vq->vq_num] = slot;
1197
1198 notify:
1199 if (notifynow) {
1200 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE);
1201 vq_sync_uring(sc, vq, BUS_DMASYNC_PREREAD);
1202 membar_producer();
1203 vq->vq_avail->idx = vq->vq_avail_idx;
1204 vq_sync_aring(sc, vq, BUS_DMASYNC_PREWRITE);
1205 membar_producer();
1206 vq->vq_queued++;
1207 vq_sync_uring(sc, vq, BUS_DMASYNC_POSTREAD);
1208 membar_consumer();
1209 if (!(vq->vq_used->flags & VRING_USED_F_NO_NOTIFY))
1210 bus_space_write_2(sc->sc_iot, sc->sc_ioh,
1211 VIRTIO_CONFIG_QUEUE_NOTIFY,
1212 vq->vq_index);
1213 }
1214 mutex_exit(&vq->vq_aring_lock);
1215
1216 return 0;
1217 }
1218
1219 /*
1220 * enqueue_abort: rollback.
1221 */
1222 int
1223 virtio_enqueue_abort(struct virtio_softc *sc, struct virtqueue *vq, int slot)
1224 {
1225 struct vq_entry *qe = &vq->vq_entries[slot];
1226 struct vring_desc *vd;
1227 int s;
1228
1229 if (qe->qe_next < 0) {
1230 vq_free_entry(vq, qe);
1231 return 0;
1232 }
1233
1234 s = slot;
1235 vd = &vq->vq_desc[0];
1236 while (vd[s].flags & VRING_DESC_F_NEXT) {
1237 s = vd[s].next;
1238 vq_free_entry(vq, qe);
1239 qe = &vq->vq_entries[s];
1240 }
1241 vq_free_entry(vq, qe);
1242 return 0;
1243 }
1244
1245 /*
1246 * Dequeue a request.
1247 */
1248 /*
1249 * dequeue: dequeue a request from uring; dmamap_sync for uring is
1250 * already done in the interrupt handler.
1251 */
1252 int
1253 virtio_dequeue(struct virtio_softc *sc, struct virtqueue *vq,
1254 int *slotp, int *lenp)
1255 {
1256 uint16_t slot, usedidx;
1257 struct vq_entry *qe;
1258
1259 if (vq->vq_used_idx == vq->vq_used->idx)
1260 return ENOENT;
1261 mutex_enter(&vq->vq_uring_lock);
1262 usedidx = vq->vq_used_idx++;
1263 mutex_exit(&vq->vq_uring_lock);
1264 usedidx %= vq->vq_num;
1265 slot = vq->vq_used->ring[usedidx].id;
1266 qe = &vq->vq_entries[slot];
1267
1268 if (qe->qe_indirect)
1269 vq_sync_indirect(sc, vq, slot, BUS_DMASYNC_POSTWRITE);
1270
1271 if (slotp)
1272 *slotp = slot;
1273 if (lenp)
1274 *lenp = vq->vq_used->ring[usedidx].len;
1275
1276 return 0;
1277 }
1278
1279 /*
1280 * dequeue_commit: complete dequeue; the slot is recycled for future use.
1281 * if you forget to call this the slot will be leaked.
1282 */
1283 int
1284 virtio_dequeue_commit(struct virtio_softc *sc, struct virtqueue *vq, int slot)
1285 {
1286 struct vq_entry *qe = &vq->vq_entries[slot];
1287 struct vring_desc *vd = &vq->vq_desc[0];
1288 int s = slot;
1289
1290 while (vd[s].flags & VRING_DESC_F_NEXT) {
1291 s = vd[s].next;
1292 vq_free_entry(vq, qe);
1293 qe = &vq->vq_entries[s];
1294 }
1295 vq_free_entry(vq, qe);
1296
1297 return 0;
1298 }
1299
1300 MODULE(MODULE_CLASS_DRIVER, virtio, "pci");
1301
1302 #ifdef _MODULE
1303 #include "ioconf.c"
1304 #endif
1305
1306 static int
1307 virtio_modcmd(modcmd_t cmd, void *opaque)
1308 {
1309 int error = 0;
1310
1311 #ifdef _MODULE
1312 switch (cmd) {
1313 case MODULE_CMD_INIT:
1314 error = config_init_component(cfdriver_ioconf_virtio,
1315 cfattach_ioconf_virtio, cfdata_ioconf_virtio);
1316 break;
1317 case MODULE_CMD_FINI:
1318 error = config_fini_component(cfdriver_ioconf_virtio,
1319 cfattach_ioconf_virtio, cfdata_ioconf_virtio);
1320 break;
1321 default:
1322 error = ENOTTY;
1323 break;
1324 }
1325 #endif
1326
1327 return error;
1328 }
1329