xref: /freebsd/sys/dev/virtio/mmio/virtio_mmio.c (revision dd21556857e8d40f66bf5ad54754d9d52669ebf7)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  * Copyright (c) 2014 The FreeBSD Foundation
4  * All rights reserved.
5  *
6  * This software was developed by SRI International and the University of
7  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
8  * ("CTSRD"), as part of the DARPA CRASH research programme.
9  *
10  * Portions of this software were developed by Andrew Turner
11  * under sponsorship from the FreeBSD Foundation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*
36  * VirtIO MMIO interface.
37  * This driver is heavily based on VirtIO PCI interface driver.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bus.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/malloc.h>
46 #include <sys/rman.h>
47 #include <sys/endian.h>
48 
49 #include <machine/bus.h>
50 #include <machine/resource.h>
51 
52 #include <dev/virtio/virtio.h>
53 #include <dev/virtio/virtqueue.h>
54 #include <dev/virtio/mmio/virtio_mmio.h>
55 
56 #include "virtio_mmio_if.h"
57 #include "virtio_bus_if.h"
58 #include "virtio_if.h"
59 
60 struct vtmmio_virtqueue {
61 	struct virtqueue	*vtv_vq;
62 	int			 vtv_no_intr;
63 };
64 
65 static int	vtmmio_detach(device_t);
66 static int	vtmmio_suspend(device_t);
67 static int	vtmmio_resume(device_t);
68 static int	vtmmio_shutdown(device_t);
69 static void	vtmmio_driver_added(device_t, driver_t *);
70 static void	vtmmio_child_detached(device_t, device_t);
71 static int	vtmmio_read_ivar(device_t, device_t, int, uintptr_t *);
72 static int	vtmmio_write_ivar(device_t, device_t, int, uintptr_t);
73 static uint64_t	vtmmio_negotiate_features(device_t, uint64_t);
74 static int	vtmmio_finalize_features(device_t);
75 static bool	vtmmio_with_feature(device_t, uint64_t);
76 static void	vtmmio_set_virtqueue(struct vtmmio_softc *sc,
77 		    struct virtqueue *vq, uint32_t size);
78 static int	vtmmio_alloc_virtqueues(device_t, int,
79 		    struct vq_alloc_info *);
80 static int	vtmmio_setup_intr(device_t, enum intr_type);
81 static void	vtmmio_stop(device_t);
82 static void	vtmmio_poll(device_t);
83 static int	vtmmio_reinit(device_t, uint64_t);
84 static void	vtmmio_reinit_complete(device_t);
85 static void	vtmmio_notify_virtqueue(device_t, uint16_t, bus_size_t);
86 static int	vtmmio_config_generation(device_t);
87 static uint8_t	vtmmio_get_status(device_t);
88 static void	vtmmio_set_status(device_t, uint8_t);
89 static void	vtmmio_read_dev_config(device_t, bus_size_t, void *, int);
90 static uint64_t	vtmmio_read_dev_config_8(struct vtmmio_softc *, bus_size_t);
91 static void	vtmmio_write_dev_config(device_t, bus_size_t, const void *, int);
92 static void	vtmmio_describe_features(struct vtmmio_softc *, const char *,
93 		    uint64_t);
94 static void	vtmmio_probe_and_attach_child(struct vtmmio_softc *);
95 static int	vtmmio_reinit_virtqueue(struct vtmmio_softc *, int);
96 static void	vtmmio_free_interrupts(struct vtmmio_softc *);
97 static void	vtmmio_free_virtqueues(struct vtmmio_softc *);
98 static void	vtmmio_release_child_resources(struct vtmmio_softc *);
99 static void	vtmmio_reset(struct vtmmio_softc *);
100 static void	vtmmio_select_virtqueue(struct vtmmio_softc *, int);
101 static void	vtmmio_vq_intr(void *);
102 
103 /*
104  * I/O port read/write wrappers.
105  */
106 #define vtmmio_write_config_1(sc, o, v)				\
107 do {								\
108 	if (sc->platform != NULL)				\
109 		VIRTIO_MMIO_PREWRITE(sc->platform, (o), (v));	\
110 	bus_write_1((sc)->res[0], (o), (v)); 			\
111 	if (sc->platform != NULL)				\
112 		VIRTIO_MMIO_NOTE(sc->platform, (o), (v));	\
113 } while (0)
114 #define vtmmio_write_config_2(sc, o, v)				\
115 do {								\
116 	if (sc->platform != NULL)				\
117 		VIRTIO_MMIO_PREWRITE(sc->platform, (o), (v));	\
118 	bus_write_2((sc)->res[0], (o), (v));			\
119 	if (sc->platform != NULL)				\
120 		VIRTIO_MMIO_NOTE(sc->platform, (o), (v));	\
121 } while (0)
122 #define vtmmio_write_config_4(sc, o, v)				\
123 do {								\
124 	if (sc->platform != NULL)				\
125 		VIRTIO_MMIO_PREWRITE(sc->platform, (o), (v));	\
126 	bus_write_4((sc)->res[0], (o), (v));			\
127 	if (sc->platform != NULL)				\
128 		VIRTIO_MMIO_NOTE(sc->platform, (o), (v));	\
129 } while (0)
130 
131 #define vtmmio_read_config_1(sc, o) \
132 	bus_read_1((sc)->res[0], (o))
133 #define vtmmio_read_config_2(sc, o) \
134 	bus_read_2((sc)->res[0], (o))
135 #define vtmmio_read_config_4(sc, o) \
136 	bus_read_4((sc)->res[0], (o))
137 
138 static device_method_t vtmmio_methods[] = {
139 	/* Device interface. */
140 	DEVMETHOD(device_attach,		  vtmmio_attach),
141 	DEVMETHOD(device_detach,		  vtmmio_detach),
142 	DEVMETHOD(device_suspend,		  vtmmio_suspend),
143 	DEVMETHOD(device_resume,		  vtmmio_resume),
144 	DEVMETHOD(device_shutdown,		  vtmmio_shutdown),
145 
146 	/* Bus interface. */
147 	DEVMETHOD(bus_driver_added,		  vtmmio_driver_added),
148 	DEVMETHOD(bus_child_detached,		  vtmmio_child_detached),
149 	DEVMETHOD(bus_child_pnpinfo,		  virtio_child_pnpinfo),
150 	DEVMETHOD(bus_read_ivar,		  vtmmio_read_ivar),
151 	DEVMETHOD(bus_write_ivar,		  vtmmio_write_ivar),
152 
153 	/* VirtIO bus interface. */
154 	DEVMETHOD(virtio_bus_negotiate_features,  vtmmio_negotiate_features),
155 	DEVMETHOD(virtio_bus_finalize_features,	  vtmmio_finalize_features),
156 	DEVMETHOD(virtio_bus_with_feature,	  vtmmio_with_feature),
157 	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtmmio_alloc_virtqueues),
158 	DEVMETHOD(virtio_bus_setup_intr,	  vtmmio_setup_intr),
159 	DEVMETHOD(virtio_bus_stop,		  vtmmio_stop),
160 	DEVMETHOD(virtio_bus_poll,		  vtmmio_poll),
161 	DEVMETHOD(virtio_bus_reinit,		  vtmmio_reinit),
162 	DEVMETHOD(virtio_bus_reinit_complete,	  vtmmio_reinit_complete),
163 	DEVMETHOD(virtio_bus_notify_vq,		  vtmmio_notify_virtqueue),
164 	DEVMETHOD(virtio_bus_config_generation,	  vtmmio_config_generation),
165 	DEVMETHOD(virtio_bus_read_device_config,  vtmmio_read_dev_config),
166 	DEVMETHOD(virtio_bus_write_device_config, vtmmio_write_dev_config),
167 
168 	DEVMETHOD_END
169 };
170 
171 DEFINE_CLASS_0(virtio_mmio, vtmmio_driver, vtmmio_methods,
172     sizeof(struct vtmmio_softc));
173 
174 MODULE_VERSION(virtio_mmio, 1);
175 
176 int
177 vtmmio_probe(device_t dev)
178 {
179 	struct vtmmio_softc *sc;
180 	int rid;
181 	uint32_t magic, version;
182 
183 	sc = device_get_softc(dev);
184 
185 	rid = 0;
186 	sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
187 	    RF_ACTIVE);
188 	if (sc->res[0] == NULL) {
189 		device_printf(dev, "Cannot allocate memory window.\n");
190 		return (ENXIO);
191 	}
192 
193 	magic = vtmmio_read_config_4(sc, VIRTIO_MMIO_MAGIC_VALUE);
194 	if (magic != VIRTIO_MMIO_MAGIC_VIRT) {
195 		device_printf(dev, "Bad magic value %#x\n", magic);
196 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
197 		return (ENXIO);
198 	}
199 
200 	version = vtmmio_read_config_4(sc, VIRTIO_MMIO_VERSION);
201 	if (version < 1 || version > 2) {
202 		device_printf(dev, "Unsupported version: %#x\n", version);
203 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
204 		return (ENXIO);
205 	}
206 
207 	if (vtmmio_read_config_4(sc, VIRTIO_MMIO_DEVICE_ID) == 0) {
208 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
209 		return (ENXIO);
210 	}
211 
212 	bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
213 
214 	device_set_desc(dev, "VirtIO MMIO adapter");
215 	return (BUS_PROBE_DEFAULT);
216 }
217 
218 static int
219 vtmmio_setup_intr(device_t dev, enum intr_type type)
220 {
221 	struct vtmmio_softc *sc;
222 	int rid;
223 	int err;
224 
225 	sc = device_get_softc(dev);
226 
227 	if (sc->platform != NULL) {
228 		err = VIRTIO_MMIO_SETUP_INTR(sc->platform, sc->dev,
229 					vtmmio_vq_intr, sc);
230 		if (err == 0) {
231 			/* Okay we have backend-specific interrupts */
232 			return (0);
233 		}
234 	}
235 
236 	rid = 0;
237 	sc->res[1] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
238 		RF_ACTIVE);
239 	if (!sc->res[1]) {
240 		device_printf(dev, "Can't allocate interrupt\n");
241 		return (ENXIO);
242 	}
243 
244 	if (bus_setup_intr(dev, sc->res[1], type | INTR_MPSAFE,
245 		NULL, vtmmio_vq_intr, sc, &sc->ih)) {
246 		device_printf(dev, "Can't setup the interrupt\n");
247 		return (ENXIO);
248 	}
249 
250 	return (0);
251 }
252 
253 int
254 vtmmio_attach(device_t dev)
255 {
256 	struct vtmmio_softc *sc;
257 	device_t child;
258 	int rid;
259 
260 	sc = device_get_softc(dev);
261 	sc->dev = dev;
262 
263 	rid = 0;
264 	sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
265 			RF_ACTIVE);
266 	if (sc->res[0] == NULL) {
267 		device_printf(dev, "Cannot allocate memory window.\n");
268 		return (ENXIO);
269 	}
270 
271 	sc->vtmmio_version = vtmmio_read_config_4(sc, VIRTIO_MMIO_VERSION);
272 
273 	vtmmio_reset(sc);
274 
275 	/* Tell the host we've noticed this device. */
276 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
277 
278 	if ((child = device_add_child(dev, NULL, -1)) == NULL) {
279 		device_printf(dev, "Cannot create child device.\n");
280 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
281 		vtmmio_detach(dev);
282 		return (ENOMEM);
283 	}
284 
285 	sc->vtmmio_child_dev = child;
286 	vtmmio_probe_and_attach_child(sc);
287 
288 	return (0);
289 }
290 
291 static int
292 vtmmio_detach(device_t dev)
293 {
294 	struct vtmmio_softc *sc;
295 	int error;
296 
297 	sc = device_get_softc(dev);
298 
299 	error = bus_generic_detach(dev);
300 	if (error)
301 		return (error);
302 
303 	vtmmio_reset(sc);
304 
305 	if (sc->res[0] != NULL) {
306 		bus_release_resource(dev, SYS_RES_MEMORY, 0,
307 		    sc->res[0]);
308 		sc->res[0] = NULL;
309 	}
310 
311 	return (0);
312 }
313 
314 static int
315 vtmmio_suspend(device_t dev)
316 {
317 
318 	return (bus_generic_suspend(dev));
319 }
320 
321 static int
322 vtmmio_resume(device_t dev)
323 {
324 
325 	return (bus_generic_resume(dev));
326 }
327 
328 static int
329 vtmmio_shutdown(device_t dev)
330 {
331 
332 	(void) bus_generic_shutdown(dev);
333 
334 	/* Forcibly stop the host device. */
335 	vtmmio_stop(dev);
336 
337 	return (0);
338 }
339 
340 static void
341 vtmmio_driver_added(device_t dev, driver_t *driver)
342 {
343 	struct vtmmio_softc *sc;
344 
345 	sc = device_get_softc(dev);
346 
347 	vtmmio_probe_and_attach_child(sc);
348 }
349 
350 static void
351 vtmmio_child_detached(device_t dev, device_t child)
352 {
353 	struct vtmmio_softc *sc;
354 
355 	sc = device_get_softc(dev);
356 
357 	vtmmio_reset(sc);
358 	vtmmio_release_child_resources(sc);
359 }
360 
361 static int
362 vtmmio_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
363 {
364 	struct vtmmio_softc *sc;
365 
366 	sc = device_get_softc(dev);
367 
368 	if (sc->vtmmio_child_dev != child)
369 		return (ENOENT);
370 
371 	switch (index) {
372 	case VIRTIO_IVAR_DEVTYPE:
373 	case VIRTIO_IVAR_SUBDEVICE:
374 		*result = vtmmio_read_config_4(sc, VIRTIO_MMIO_DEVICE_ID);
375 		break;
376 	case VIRTIO_IVAR_VENDOR:
377 		*result = vtmmio_read_config_4(sc, VIRTIO_MMIO_VENDOR_ID);
378 		break;
379 	case VIRTIO_IVAR_SUBVENDOR:
380 	case VIRTIO_IVAR_DEVICE:
381 		/*
382 		 * Dummy value for fields not present in this bus.  Used by
383 		 * bus-agnostic virtio_child_pnpinfo.
384 		 */
385 		*result = 0;
386 		break;
387 	case VIRTIO_IVAR_MODERN:
388 		/*
389 		 * There are several modern (aka MMIO v2) spec compliance
390 		 * issues with this driver, but keep the status quo.
391 		 */
392 		*result = sc->vtmmio_version > 1;
393 		break;
394 	default:
395 		return (ENOENT);
396 	}
397 
398 	return (0);
399 }
400 
401 static int
402 vtmmio_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
403 {
404 	struct vtmmio_softc *sc;
405 
406 	sc = device_get_softc(dev);
407 
408 	if (sc->vtmmio_child_dev != child)
409 		return (ENOENT);
410 
411 	switch (index) {
412 	case VIRTIO_IVAR_FEATURE_DESC:
413 		sc->vtmmio_child_feat_desc = (void *) value;
414 		break;
415 	default:
416 		return (ENOENT);
417 	}
418 
419 	return (0);
420 }
421 
422 static uint64_t
423 vtmmio_negotiate_features(device_t dev, uint64_t child_features)
424 {
425 	struct vtmmio_softc *sc;
426 	uint64_t host_features, features;
427 
428 	sc = device_get_softc(dev);
429 
430 	if (sc->vtmmio_version > 1) {
431 		child_features |= VIRTIO_F_VERSION_1;
432 	}
433 
434 	vtmmio_write_config_4(sc, VIRTIO_MMIO_HOST_FEATURES_SEL, 1);
435 	host_features = vtmmio_read_config_4(sc, VIRTIO_MMIO_HOST_FEATURES);
436 	host_features <<= 32;
437 
438 	vtmmio_write_config_4(sc, VIRTIO_MMIO_HOST_FEATURES_SEL, 0);
439 	host_features |= vtmmio_read_config_4(sc, VIRTIO_MMIO_HOST_FEATURES);
440 
441 	vtmmio_describe_features(sc, "host", host_features);
442 
443 	/*
444 	 * Limit negotiated features to what the driver, virtqueue, and
445 	 * host all support.
446 	 */
447 	features = host_features & child_features;
448 	features = virtio_filter_transport_features(features);
449 	sc->vtmmio_features = features;
450 
451 	vtmmio_describe_features(sc, "negotiated", features);
452 
453 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES_SEL, 1);
454 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES, features >> 32);
455 
456 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES_SEL, 0);
457 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES, features);
458 
459 	return (features);
460 }
461 
462 static int
463 vtmmio_finalize_features(device_t dev)
464 {
465 	struct vtmmio_softc *sc;
466 	uint8_t status;
467 
468 	sc = device_get_softc(dev);
469 
470 	if (sc->vtmmio_version > 1) {
471 		/*
472 		 * Must re-read the status after setting it to verify the
473 		 * negotiated features were accepted by the device.
474 		 */
475 		vtmmio_set_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
476 
477 		status = vtmmio_get_status(dev);
478 		if ((status & VIRTIO_CONFIG_S_FEATURES_OK) == 0) {
479 			device_printf(dev, "desired features were not accepted\n");
480 			return (ENOTSUP);
481 		}
482 	}
483 
484 	return (0);
485 }
486 
487 static bool
488 vtmmio_with_feature(device_t dev, uint64_t feature)
489 {
490 	struct vtmmio_softc *sc;
491 
492 	sc = device_get_softc(dev);
493 
494 	return ((sc->vtmmio_features & feature) != 0);
495 }
496 
497 static void
498 vtmmio_set_virtqueue(struct vtmmio_softc *sc, struct virtqueue *vq,
499     uint32_t size)
500 {
501 	vm_paddr_t paddr;
502 
503 	vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_NUM, size);
504 
505 	if (sc->vtmmio_version == 1) {
506 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_ALIGN,
507 		    VIRTIO_MMIO_VRING_ALIGN);
508 		paddr = virtqueue_paddr(vq);
509 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN,
510 		    paddr >> PAGE_SHIFT);
511 	} else {
512 		paddr = virtqueue_desc_paddr(vq);
513 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_DESC_LOW,
514 		    paddr);
515 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_DESC_HIGH,
516 		    ((uint64_t)paddr) >> 32);
517 
518 		paddr = virtqueue_avail_paddr(vq);
519 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_AVAIL_LOW,
520 		    paddr);
521 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_AVAIL_HIGH,
522 		    ((uint64_t)paddr) >> 32);
523 
524 		paddr = virtqueue_used_paddr(vq);
525 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_USED_LOW,
526 		    paddr);
527 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_USED_HIGH,
528 		    ((uint64_t)paddr) >> 32);
529 
530 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_READY, 1);
531 	}
532 }
533 
534 static int
535 vtmmio_alloc_virtqueues(device_t dev, int nvqs,
536     struct vq_alloc_info *vq_info)
537 {
538 	struct vtmmio_virtqueue *vqx;
539 	struct vq_alloc_info *info;
540 	struct vtmmio_softc *sc;
541 	struct virtqueue *vq;
542 	uint32_t size;
543 	int idx, error;
544 
545 	sc = device_get_softc(dev);
546 
547 	if (sc->vtmmio_nvqs != 0)
548 		return (EALREADY);
549 	if (nvqs <= 0)
550 		return (EINVAL);
551 
552 	sc->vtmmio_vqs = malloc(nvqs * sizeof(struct vtmmio_virtqueue),
553 	    M_DEVBUF, M_NOWAIT | M_ZERO);
554 	if (sc->vtmmio_vqs == NULL)
555 		return (ENOMEM);
556 
557 	if (sc->vtmmio_version == 1) {
558 		vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_PAGE_SIZE,
559 		    (1 << PAGE_SHIFT));
560 	}
561 
562 	for (idx = 0; idx < nvqs; idx++) {
563 		vqx = &sc->vtmmio_vqs[idx];
564 		info = &vq_info[idx];
565 
566 		vtmmio_select_virtqueue(sc, idx);
567 		size = vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX);
568 
569 		error = virtqueue_alloc(dev, idx, size,
570 		    VIRTIO_MMIO_QUEUE_NOTIFY, VIRTIO_MMIO_VRING_ALIGN,
571 		    ~(vm_paddr_t)0, info, &vq);
572 		if (error) {
573 			device_printf(dev,
574 			    "cannot allocate virtqueue %d: %d\n",
575 			    idx, error);
576 			break;
577 		}
578 
579 		vtmmio_set_virtqueue(sc, vq, size);
580 
581 		vqx->vtv_vq = *info->vqai_vq = vq;
582 		vqx->vtv_no_intr = info->vqai_intr == NULL;
583 
584 		sc->vtmmio_nvqs++;
585 	}
586 
587 	if (error)
588 		vtmmio_free_virtqueues(sc);
589 
590 	return (error);
591 }
592 
593 static void
594 vtmmio_stop(device_t dev)
595 {
596 
597 	vtmmio_reset(device_get_softc(dev));
598 }
599 
600 static void
601 vtmmio_poll(device_t dev)
602 {
603 	struct vtmmio_softc *sc;
604 
605 	sc = device_get_softc(dev);
606 
607 	if (sc->platform != NULL)
608 		VIRTIO_MMIO_POLL(sc->platform);
609 }
610 
611 static int
612 vtmmio_reinit(device_t dev, uint64_t features)
613 {
614 	struct vtmmio_softc *sc;
615 	int idx, error;
616 
617 	sc = device_get_softc(dev);
618 
619 	if (vtmmio_get_status(dev) != VIRTIO_CONFIG_STATUS_RESET)
620 		vtmmio_stop(dev);
621 
622 	/*
623 	 * Quickly drive the status through ACK and DRIVER. The device
624 	 * does not become usable again until vtmmio_reinit_complete().
625 	 */
626 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
627 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
628 
629 	/*
630 	 * TODO: Check that features are not added as to what was
631 	 * originally negotiated.
632 	 */
633 	vtmmio_negotiate_features(dev, features);
634 	error = vtmmio_finalize_features(dev);
635 	if (error) {
636 		device_printf(dev, "cannot finalize features during reinit\n");
637 		return (error);
638 	}
639 
640 	if (sc->vtmmio_version == 1) {
641 		vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_PAGE_SIZE,
642 		    (1 << PAGE_SHIFT));
643 	}
644 
645 	for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
646 		error = vtmmio_reinit_virtqueue(sc, idx);
647 		if (error)
648 			return (error);
649 	}
650 
651 	return (0);
652 }
653 
654 static void
655 vtmmio_reinit_complete(device_t dev)
656 {
657 
658 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
659 }
660 
661 static void
662 vtmmio_notify_virtqueue(device_t dev, uint16_t queue, bus_size_t offset)
663 {
664 	struct vtmmio_softc *sc;
665 
666 	sc = device_get_softc(dev);
667 	MPASS(offset == VIRTIO_MMIO_QUEUE_NOTIFY);
668 
669 	vtmmio_write_config_4(sc, offset, queue);
670 }
671 
672 static int
673 vtmmio_config_generation(device_t dev)
674 {
675 	struct vtmmio_softc *sc;
676 	uint32_t gen;
677 
678 	sc = device_get_softc(dev);
679 
680 	if (sc->vtmmio_version > 1)
681 		gen = vtmmio_read_config_4(sc, VIRTIO_MMIO_CONFIG_GENERATION);
682 	else
683 		gen = 0;
684 
685 	return (gen);
686 }
687 
688 static uint8_t
689 vtmmio_get_status(device_t dev)
690 {
691 	struct vtmmio_softc *sc;
692 
693 	sc = device_get_softc(dev);
694 
695 	return (vtmmio_read_config_4(sc, VIRTIO_MMIO_STATUS));
696 }
697 
698 static void
699 vtmmio_set_status(device_t dev, uint8_t status)
700 {
701 	struct vtmmio_softc *sc;
702 
703 	sc = device_get_softc(dev);
704 
705 	if (status != VIRTIO_CONFIG_STATUS_RESET)
706 		status |= vtmmio_get_status(dev);
707 
708 	vtmmio_write_config_4(sc, VIRTIO_MMIO_STATUS, status);
709 }
710 
711 static void
712 vtmmio_read_dev_config(device_t dev, bus_size_t offset,
713     void *dst, int length)
714 {
715 	struct vtmmio_softc *sc;
716 	bus_size_t off;
717 	uint8_t *d;
718 	int size;
719 
720 	sc = device_get_softc(dev);
721 	off = VIRTIO_MMIO_CONFIG + offset;
722 
723 	/*
724 	 * The non-legacy MMIO specification adds the following restriction:
725 	 *
726 	 *   4.2.2.2: For the device-specific configuration space, the driver
727 	 *   MUST use 8 bit wide accesses for 8 bit wide fields, 16 bit wide
728 	 *   and aligned accesses for 16 bit wide fields and 32 bit wide and
729 	 *   aligned accesses for 32 and 64 bit wide fields.
730 	 *
731 	 * The endianness also varies between non-legacy and legacy:
732 	 *
733 	 *   2.4: Note: The device configuration space uses the little-endian
734 	 *   format for multi-byte fields.
735 	 *
736 	 *   2.4.3: Note that for legacy interfaces, device configuration space
737 	 *   is generally the guest’s native endian, rather than PCI’s
738 	 *   little-endian. The correct endian-ness is documented for each
739 	 *   device.
740 	 */
741 	if (sc->vtmmio_version > 1) {
742 		switch (length) {
743 		case 1:
744 			*(uint8_t *)dst = vtmmio_read_config_1(sc, off);
745 			break;
746 		case 2:
747 			*(uint16_t *)dst =
748 			    le16toh(vtmmio_read_config_2(sc, off));
749 			break;
750 		case 4:
751 			*(uint32_t *)dst =
752 			    le32toh(vtmmio_read_config_4(sc, off));
753 			break;
754 		case 8:
755 			*(uint64_t *)dst = vtmmio_read_dev_config_8(sc, off);
756 			break;
757 		default:
758 			panic("%s: invalid length %d\n", __func__, length);
759 		}
760 
761 		return;
762 	}
763 
764 	for (d = dst; length > 0; d += size, off += size, length -= size) {
765 #ifdef ALLOW_WORD_ALIGNED_ACCESS
766 		if (length >= 4) {
767 			size = 4;
768 			*(uint32_t *)d = vtmmio_read_config_4(sc, off);
769 		} else if (length >= 2) {
770 			size = 2;
771 			*(uint16_t *)d = vtmmio_read_config_2(sc, off);
772 		} else
773 #endif
774 		{
775 			size = 1;
776 			*d = vtmmio_read_config_1(sc, off);
777 		}
778 	}
779 }
780 
781 static uint64_t
782 vtmmio_read_dev_config_8(struct vtmmio_softc *sc, bus_size_t off)
783 {
784 	device_t dev;
785 	int gen;
786 	uint32_t val0, val1;
787 
788 	dev = sc->dev;
789 
790 	do {
791 		gen = vtmmio_config_generation(dev);
792 		val0 = le32toh(vtmmio_read_config_4(sc, off));
793 		val1 = le32toh(vtmmio_read_config_4(sc, off + 4));
794 	} while (gen != vtmmio_config_generation(dev));
795 
796 	return (((uint64_t) val1 << 32) | val0);
797 }
798 
799 static void
800 vtmmio_write_dev_config(device_t dev, bus_size_t offset,
801     const void *src, int length)
802 {
803 	struct vtmmio_softc *sc;
804 	bus_size_t off;
805 	const uint8_t *s;
806 	int size;
807 
808 	sc = device_get_softc(dev);
809 	off = VIRTIO_MMIO_CONFIG + offset;
810 
811 	/*
812 	 * The non-legacy MMIO specification adds size and alignment
813 	 * restrctions. It also changes the endianness from native-endian to
814 	 * little-endian. See vtmmio_read_dev_config.
815 	 */
816 	if (sc->vtmmio_version > 1) {
817 		switch (length) {
818 		case 1:
819 			vtmmio_write_config_1(sc, off, *(const uint8_t *)src);
820 			break;
821 		case 2:
822 			vtmmio_write_config_2(sc, off,
823 			    htole16(*(const uint16_t *)src));
824 			break;
825 		case 4:
826 			vtmmio_write_config_4(sc, off,
827 			    htole32(*(const uint32_t *)src));
828 			break;
829 		case 8:
830 			vtmmio_write_config_4(sc, off,
831 			    htole32(*(const uint64_t *)src));
832 			vtmmio_write_config_4(sc, off + 4,
833 			    htole32((*(const uint64_t *)src) >> 32));
834 			break;
835 		default:
836 			panic("%s: invalid length %d\n", __func__, length);
837 		}
838 
839 		return;
840 	}
841 
842 	for (s = src; length > 0; s += size, off += size, length -= size) {
843 #ifdef ALLOW_WORD_ALIGNED_ACCESS
844 		if (length >= 4) {
845 			size = 4;
846 			vtmmio_write_config_4(sc, off, *(uint32_t *)s);
847 		} else if (length >= 2) {
848 			size = 2;
849 			vtmmio_write_config_2(sc, off, *(uint16_t *)s);
850 		} else
851 #endif
852 		{
853 			size = 1;
854 			vtmmio_write_config_1(sc, off, *s);
855 		}
856 	}
857 }
858 
859 static void
860 vtmmio_describe_features(struct vtmmio_softc *sc, const char *msg,
861     uint64_t features)
862 {
863 	device_t dev, child;
864 
865 	dev = sc->dev;
866 	child = sc->vtmmio_child_dev;
867 
868 	if (device_is_attached(child) || bootverbose == 0)
869 		return;
870 
871 	virtio_describe(dev, msg, features, sc->vtmmio_child_feat_desc);
872 }
873 
874 static void
875 vtmmio_probe_and_attach_child(struct vtmmio_softc *sc)
876 {
877 	device_t dev, child;
878 
879 	dev = sc->dev;
880 	child = sc->vtmmio_child_dev;
881 
882 	if (child == NULL)
883 		return;
884 
885 	if (device_get_state(child) != DS_NOTPRESENT) {
886 		return;
887 	}
888 
889 	if (device_probe(child) != 0) {
890 		return;
891 	}
892 
893 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
894 	if (device_attach(child) != 0) {
895 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
896 		vtmmio_reset(sc);
897 		vtmmio_release_child_resources(sc);
898 		/* Reset status for future attempt. */
899 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
900 	} else {
901 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
902 		VIRTIO_ATTACH_COMPLETED(child);
903 	}
904 }
905 
906 static int
907 vtmmio_reinit_virtqueue(struct vtmmio_softc *sc, int idx)
908 {
909 	struct vtmmio_virtqueue *vqx;
910 	struct virtqueue *vq;
911 	int error;
912 	uint16_t size;
913 
914 	vqx = &sc->vtmmio_vqs[idx];
915 	vq = vqx->vtv_vq;
916 
917 	KASSERT(vq != NULL, ("%s: vq %d not allocated", __func__, idx));
918 
919 	vtmmio_select_virtqueue(sc, idx);
920 	size = vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX);
921 
922 	error = virtqueue_reinit(vq, size);
923 	if (error)
924 		return (error);
925 
926 	vtmmio_set_virtqueue(sc, vq, size);
927 
928 	return (0);
929 }
930 
931 static void
932 vtmmio_free_interrupts(struct vtmmio_softc *sc)
933 {
934 
935 	if (sc->ih != NULL)
936 		bus_teardown_intr(sc->dev, sc->res[1], sc->ih);
937 
938 	if (sc->res[1] != NULL)
939 		bus_release_resource(sc->dev, SYS_RES_IRQ, 0, sc->res[1]);
940 }
941 
942 static void
943 vtmmio_free_virtqueues(struct vtmmio_softc *sc)
944 {
945 	struct vtmmio_virtqueue *vqx;
946 	int idx;
947 
948 	for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
949 		vqx = &sc->vtmmio_vqs[idx];
950 
951 		vtmmio_select_virtqueue(sc, idx);
952 		if (sc->vtmmio_version > 1) {
953 			vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_READY, 0);
954 			vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_READY);
955 		} else
956 			vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN, 0);
957 
958 		virtqueue_free(vqx->vtv_vq);
959 		vqx->vtv_vq = NULL;
960 	}
961 
962 	free(sc->vtmmio_vqs, M_DEVBUF);
963 	sc->vtmmio_vqs = NULL;
964 	sc->vtmmio_nvqs = 0;
965 }
966 
967 static void
968 vtmmio_release_child_resources(struct vtmmio_softc *sc)
969 {
970 
971 	vtmmio_free_interrupts(sc);
972 	vtmmio_free_virtqueues(sc);
973 }
974 
975 static void
976 vtmmio_reset(struct vtmmio_softc *sc)
977 {
978 
979 	/*
980 	 * Setting the status to RESET sets the host device to
981 	 * the original, uninitialized state.
982 	 */
983 	vtmmio_set_status(sc->dev, VIRTIO_CONFIG_STATUS_RESET);
984 }
985 
986 static void
987 vtmmio_select_virtqueue(struct vtmmio_softc *sc, int idx)
988 {
989 
990 	vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_SEL, idx);
991 }
992 
993 static void
994 vtmmio_vq_intr(void *arg)
995 {
996 	struct vtmmio_virtqueue *vqx;
997 	struct vtmmio_softc *sc;
998 	struct virtqueue *vq;
999 	uint32_t status;
1000 	int idx;
1001 
1002 	sc = arg;
1003 
1004 	status = vtmmio_read_config_4(sc, VIRTIO_MMIO_INTERRUPT_STATUS);
1005 	vtmmio_write_config_4(sc, VIRTIO_MMIO_INTERRUPT_ACK, status);
1006 
1007 	/* The config changed */
1008 	if (status & VIRTIO_MMIO_INT_CONFIG)
1009 		if (sc->vtmmio_child_dev != NULL)
1010 			VIRTIO_CONFIG_CHANGE(sc->vtmmio_child_dev);
1011 
1012 	/* Notify all virtqueues. */
1013 	if (status & VIRTIO_MMIO_INT_VRING) {
1014 		for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
1015 			vqx = &sc->vtmmio_vqs[idx];
1016 			if (vqx->vtv_no_intr == 0) {
1017 				vq = vqx->vtv_vq;
1018 				virtqueue_intr(vq);
1019 			}
1020 		}
1021 	}
1022 }
1023