xref: /freebsd/sys/dev/beri/virtio/virtio_block.c (revision 8657387683946d0c03e09fe77029edfe309eeb20)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * This software was developed by SRI International and the University of
6  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
7  * ("CTSRD"), as part of the DARPA CRASH research programme.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * BERI virtio block backend driver
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/bus.h>
41 #include <sys/kernel.h>
42 #include <sys/module.h>
43 #include <sys/rman.h>
44 #include <sys/conf.h>
45 #include <sys/stat.h>
46 #include <sys/endian.h>
47 #include <sys/disk.h>
48 #include <sys/vnode.h>
49 #include <sys/fcntl.h>
50 #include <sys/kthread.h>
51 #include <sys/buf.h>
52 #include <sys/mdioctl.h>
53 #include <sys/namei.h>
54 
55 #include <machine/bus.h>
56 #include <machine/fdt.h>
57 #include <machine/cpu.h>
58 #include <machine/intr.h>
59 
60 #include <dev/fdt/fdt_common.h>
61 #include <dev/ofw/openfirm.h>
62 #include <dev/ofw/ofw_bus.h>
63 #include <dev/ofw/ofw_bus_subr.h>
64 
65 #include <dev/beri/virtio/virtio.h>
66 #include <dev/beri/virtio/virtio_mmio_platform.h>
67 #include <dev/altera/pio/pio.h>
68 #include <dev/virtio/mmio/virtio_mmio.h>
69 #include <dev/virtio/block/virtio_blk.h>
70 #include <dev/virtio/virtio_ids.h>
71 #include <dev/virtio/virtio_config.h>
72 #include <dev/virtio/virtio_ring.h>
73 
74 #include "pio_if.h"
75 
76 #define DPRINTF(fmt, ...)
77 
78 /* We use indirect descriptors */
79 #define	NUM_DESCS	1
80 #define	NUM_QUEUES	1
81 
82 #define	VTBLK_BLK_ID_BYTES	20
83 #define	VTBLK_MAXSEGS		256
84 
85 struct beri_vtblk_softc {
86 	struct resource		*res[1];
87 	bus_space_tag_t		bst;
88 	bus_space_handle_t	bsh;
89 	struct cdev		*cdev;
90 	device_t		dev;
91 	int			opened;
92 	device_t		pio_recv;
93 	device_t		pio_send;
94 	struct vqueue_info	vs_queues[NUM_QUEUES];
95 	char			ident[VTBLK_BLK_ID_BYTES];
96 	struct ucred		*cred;
97 	struct vnode		*vnode;
98 	struct thread		*vtblk_ktd;
99 	struct sx		sc_mtx;
100 	int			beri_mem_offset;
101 	struct md_ioctl		*mdio;
102 	struct virtio_blk_config *cfg;
103 };
104 
105 static struct resource_spec beri_spec[] = {
106 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
107 	{ -1, 0 }
108 };
109 
110 static int
111 vtblk_rdwr(struct beri_vtblk_softc *sc, struct iovec *iov,
112 	int cnt, int offset, int operation, int iolen)
113 {
114 	struct vnode *vp;
115 	struct mount *mp;
116 	struct uio auio;
117 	int error;
118 
119 	bzero(&auio, sizeof(auio));
120 
121 	vp = sc->vnode;
122 
123 	KASSERT(vp != NULL, ("file not opened"));
124 
125 	auio.uio_iov = iov;
126 	auio.uio_iovcnt = cnt;
127 	auio.uio_offset = offset;
128 	auio.uio_segflg = UIO_SYSSPACE;
129 	auio.uio_rw = operation;
130 	auio.uio_resid = iolen;
131 	auio.uio_td = curthread;
132 
133 	if (operation == 0) {
134 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
135 		error = VOP_READ(vp, &auio, IO_DIRECT, sc->cred);
136 		VOP_UNLOCK(vp, 0);
137 	} else {
138 		(void) vn_start_write(vp, &mp, V_WAIT);
139 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
140 		error = VOP_WRITE(vp, &auio, IO_SYNC, sc->cred);
141 		VOP_UNLOCK(vp, 0);
142 		vn_finished_write(mp);
143 	}
144 
145 	return (error);
146 }
147 
148 static void
149 vtblk_proc(struct beri_vtblk_softc *sc, struct vqueue_info *vq)
150 {
151 	struct iovec iov[VTBLK_MAXSEGS + 2];
152 	uint16_t flags[VTBLK_MAXSEGS + 2];
153 	struct virtio_blk_outhdr *vbh;
154 	struct iovec *tiov;
155 	uint8_t *status;
156 	off_t offset;
157 	int iolen;
158 	int type;
159 	int i, n;
160 	int err;
161 
162 	n = vq_getchain(sc->beri_mem_offset, vq, iov,
163 		VTBLK_MAXSEGS + 2, flags);
164 	KASSERT(n >= 2 && n <= VTBLK_MAXSEGS + 2,
165 		("wrong n value %d", n));
166 
167 	tiov = getcopy(iov, n);
168 	vbh = iov[0].iov_base;
169 
170 	status = iov[n-1].iov_base;
171 	KASSERT(iov[n-1].iov_len == 1,
172 		("iov_len == %d", iov[n-1].iov_len));
173 
174 	type = be32toh(vbh->type) & ~VIRTIO_BLK_T_BARRIER;
175 	offset = be64toh(vbh->sector) * DEV_BSIZE;
176 
177 	iolen = 0;
178 	for (i = 1; i < (n-1); i++) {
179 		iolen += iov[i].iov_len;
180 	}
181 
182 	switch (type) {
183 	case VIRTIO_BLK_T_OUT:
184 	case VIRTIO_BLK_T_IN:
185 		err = vtblk_rdwr(sc, tiov + 1, i - 1,
186 			offset, type, iolen);
187 		break;
188 	case VIRTIO_BLK_T_GET_ID:
189 		/* Assume a single buffer */
190 		strlcpy(iov[1].iov_base, sc->ident,
191 		    MIN(iov[1].iov_len, sizeof(sc->ident)));
192 		err = 0;
193 		break;
194 	case VIRTIO_BLK_T_FLUSH:
195 		/* Possible? */
196 	default:
197 		err = -ENOSYS;
198 		break;
199 	}
200 
201 	if (err < 0) {
202 		if (err == -ENOSYS) {
203 			*status = VIRTIO_BLK_S_UNSUPP;
204 		} else
205 			*status = VIRTIO_BLK_S_IOERR;
206 	} else
207 		*status = VIRTIO_BLK_S_OK;
208 
209 	free(tiov, M_DEVBUF);
210 	vq_relchain(vq, iov, n, 1);
211 }
212 
213 static int
214 close_file(struct beri_vtblk_softc *sc, struct thread *td)
215 {
216 	int error;
217 
218 	if (sc->vnode != NULL) {
219 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
220 		sc->vnode->v_vflag &= ~VV_MD;
221 		VOP_UNLOCK(sc->vnode, 0);
222 		error = vn_close(sc->vnode, (FREAD|FWRITE),
223 				sc->cred, td);
224 		if (error != 0)
225 			return (error);
226 		sc->vnode = NULL;
227 	}
228 
229 	if (sc->cred != NULL)
230 		crfree(sc->cred);
231 
232 	return (0);
233 }
234 
235 static int
236 open_file(struct beri_vtblk_softc *sc, struct thread *td)
237 {
238 	struct nameidata nd;
239 	struct vattr vattr;
240 	int error;
241 	int flags;
242 
243 	flags = (FREAD | FWRITE);
244 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE,
245 		sc->mdio->md_file, td);
246 	error = vn_open(&nd, &flags, 0, NULL);
247 	if (error != 0)
248 		return (error);
249 	NDFREE(&nd, NDF_ONLY_PNBUF);
250 
251 	if (nd.ni_vp->v_type != VREG) {
252 		return (EINVAL);
253 	}
254 
255 	error = VOP_GETATTR(nd.ni_vp, &vattr, td->td_ucred);
256 	if (error != 0)
257 		return (error);
258 
259 	if (VOP_ISLOCKED(nd.ni_vp) != LK_EXCLUSIVE) {
260 		vn_lock(nd.ni_vp, LK_UPGRADE | LK_RETRY);
261 		if (nd.ni_vp->v_iflag & VI_DOOMED) {
262 			return (1);
263 		}
264 	}
265 	nd.ni_vp->v_vflag |= VV_MD;
266 	VOP_UNLOCK(nd.ni_vp, 0);
267 
268 	sc->vnode = nd.ni_vp;
269 	sc->cred = crhold(td->td_ucred);
270 
271 	return (0);
272 }
273 
274 static int
275 vtblk_notify(struct beri_vtblk_softc *sc)
276 {
277 	struct vqueue_info *vq;
278 	int queue;
279 	int reg;
280 
281 	vq = &sc->vs_queues[0];
282 	if (!vq_ring_ready(vq))
283 		return (0);
284 
285 	if (!sc->opened)
286 		return (0);
287 
288 	reg = READ2(sc, VIRTIO_MMIO_QUEUE_NOTIFY);
289 	queue = be16toh(reg);
290 
291 	KASSERT(queue == 0, ("we support single queue only"));
292 
293 	/* Process new descriptors */
294 	vq = &sc->vs_queues[queue];
295 	vq->vq_save_used = be16toh(vq->vq_used->idx);
296 	while (vq_has_descs(vq))
297 		vtblk_proc(sc, vq);
298 
299 	/* Interrupt the other side */
300 	if ((be16toh(vq->vq_avail->flags) & VRING_AVAIL_F_NO_INTERRUPT) == 0) {
301 		reg = htobe32(VIRTIO_MMIO_INT_VRING);
302 		WRITE4(sc, VIRTIO_MMIO_INTERRUPT_STATUS, reg);
303 		PIO_SET(sc->pio_send, Q_INTR, 1);
304 	}
305 
306 	return (0);
307 }
308 
309 static int
310 vq_init(struct beri_vtblk_softc *sc)
311 {
312 	struct vqueue_info *vq;
313 	uint8_t *base;
314 	int size;
315 	int reg;
316 	int pfn;
317 
318 	vq = &sc->vs_queues[0];
319 	vq->vq_qsize = NUM_DESCS;
320 
321 	reg = READ4(sc, VIRTIO_MMIO_QUEUE_PFN);
322 	pfn = be32toh(reg);
323 	vq->vq_pfn = pfn;
324 
325 	size = vring_size(vq->vq_qsize, VRING_ALIGN);
326 	base = paddr_map(sc->beri_mem_offset,
327 		(pfn << PAGE_SHIFT), size);
328 
329 	/* First pages are descriptors */
330 	vq->vq_desc = (struct vring_desc *)base;
331 	base += vq->vq_qsize * sizeof(struct vring_desc);
332 
333 	/* Then avail ring */
334 	vq->vq_avail = (struct vring_avail *)base;
335 	base += (2 + vq->vq_qsize + 1) * sizeof(uint16_t);
336 
337 	/* Then it's rounded up to the next page */
338 	base = (uint8_t *)roundup2((uintptr_t)base, VRING_ALIGN);
339 
340 	/* And the last pages are the used ring */
341 	vq->vq_used = (struct vring_used *)base;
342 
343 	/* Mark queue as allocated, and start at 0 when we use it. */
344 	vq->vq_flags = VQ_ALLOC;
345 	vq->vq_last_avail = 0;
346 
347 	return (0);
348 }
349 
350 
351 static void
352 vtblk_thread(void *arg)
353 {
354 	struct beri_vtblk_softc *sc;
355 	int err;
356 
357 	sc = arg;
358 
359 	sx_xlock(&sc->sc_mtx);
360 	for (;;) {
361 		err = msleep(sc, &sc->sc_mtx, PCATCH | PZERO, "prd", hz);
362 		vtblk_notify(sc);
363 	}
364 	sx_xunlock(&sc->sc_mtx);
365 
366 	kthread_exit();
367 }
368 
369 static int
370 backend_info(struct beri_vtblk_softc *sc)
371 {
372 	struct virtio_blk_config *cfg;
373 	uint32_t *s;
374 	int reg;
375 	int i;
376 
377 	/* Specify that we provide block device */
378 	reg = htobe32(VIRTIO_ID_BLOCK);
379 	WRITE4(sc, VIRTIO_MMIO_DEVICE_ID, reg);
380 
381 	/* Queue size */
382 	reg = htobe32(NUM_DESCS);
383 	WRITE4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX, reg);
384 
385 	/* Our features */
386 	reg = htobe32(VIRTIO_RING_F_INDIRECT_DESC
387 	    | VIRTIO_BLK_F_BLK_SIZE
388 	    | VIRTIO_BLK_F_SEG_MAX);
389 	WRITE4(sc, VIRTIO_MMIO_HOST_FEATURES, reg);
390 
391 	cfg = sc->cfg;
392 	cfg->capacity = htobe64(sc->mdio->md_mediasize / DEV_BSIZE);
393 	cfg->size_max = 0; /* not negotiated */
394 	cfg->seg_max = htobe32(VTBLK_MAXSEGS);
395 	cfg->blk_size = htobe32(DEV_BSIZE);
396 
397 	s = (uint32_t *)cfg;
398 
399 	for (i = 0; i < sizeof(struct virtio_blk_config); i+=4) {
400 		WRITE4(sc, VIRTIO_MMIO_CONFIG + i, *s);
401 		s+=1;
402 	}
403 
404 	sprintf(sc->ident, "Virtio block backend");
405 
406 	return (0);
407 }
408 
409 static void
410 vtblk_intr(void *arg)
411 {
412 	struct beri_vtblk_softc *sc;
413 	int pending;
414 	int reg;
415 
416 	sc = arg;
417 
418 	reg = PIO_READ(sc->pio_recv);
419 
420 	/* Ack */
421 	PIO_SET(sc->pio_recv, reg, 0);
422 
423 	pending = htobe32(reg);
424 
425 	if (pending & Q_PFN) {
426 		vq_init(sc);
427 	}
428 
429 	if (pending & Q_NOTIFY) {
430 		wakeup(sc);
431 	}
432 }
433 
434 static int
435 beri_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
436 		int flags, struct thread *td)
437 {
438 	struct beri_vtblk_softc *sc;
439 	int err;
440 
441 	sc = dev->si_drv1;
442 
443 	switch (cmd) {
444 	case MDIOCATTACH:
445 		/* take file as argument */
446 		if (sc->vnode != NULL) {
447 			/* Already opened */
448 			return (1);
449 		}
450 		sc->mdio = (struct md_ioctl *)addr;
451 		backend_info(sc);
452 		DPRINTF("opening file, td 0x%08x\n", (int)td);
453 		err = open_file(sc, td);
454 		if (err)
455 			return (err);
456 		PIO_SETUP_IRQ(sc->pio_recv, vtblk_intr, sc);
457 		sc->opened = 1;
458 		break;
459 	case MDIOCDETACH:
460 		if (sc->vnode == NULL) {
461 			/* File not opened */
462 			return (1);
463 		}
464 		sc->opened = 0;
465 		DPRINTF("closing file, td 0x%08x\n", (int)td);
466 		err = close_file(sc, td);
467 		if (err)
468 			return (err);
469 		PIO_TEARDOWN_IRQ(sc->pio_recv);
470 		break;
471 	default:
472 		break;
473 	}
474 
475 	return (0);
476 }
477 
478 static struct cdevsw beri_cdevsw = {
479 	.d_version =	D_VERSION,
480 	.d_ioctl =	beri_ioctl,
481 	.d_name =	"virtio block backend",
482 };
483 
484 static int
485 beri_vtblk_probe(device_t dev)
486 {
487 
488 	if (!ofw_bus_status_okay(dev))
489 		return (ENXIO);
490 
491 	if (!ofw_bus_is_compatible(dev, "sri-cambridge,beri-vtblk"))
492 		return (ENXIO);
493 
494 	device_set_desc(dev, "SRI-Cambridge BERI block");
495 	return (BUS_PROBE_DEFAULT);
496 }
497 
498 static int
499 beri_vtblk_attach(device_t dev)
500 {
501 	struct beri_vtblk_softc *sc;
502 	int error;
503 
504 	sc = device_get_softc(dev);
505 	sc->dev = dev;
506 
507 	if (bus_alloc_resources(dev, beri_spec, sc->res)) {
508 		device_printf(dev, "could not allocate resources\n");
509 		return (ENXIO);
510 	}
511 
512 	/* Memory interface */
513 	sc->bst = rman_get_bustag(sc->res[0]);
514 	sc->bsh = rman_get_bushandle(sc->res[0]);
515 
516 	sc->cfg = malloc(sizeof(struct virtio_blk_config),
517 		M_DEVBUF, M_NOWAIT|M_ZERO);
518 
519 	sx_init(&sc->sc_mtx, device_get_nameunit(sc->dev));
520 
521 	error = kthread_add(vtblk_thread, sc, NULL, &sc->vtblk_ktd,
522 		0, 0, "beri_virtio_block");
523 	if (error) {
524 		device_printf(dev, "cannot create kthread\n");
525 		return (ENXIO);
526 	}
527 
528 	if (setup_offset(dev, &sc->beri_mem_offset) != 0)
529 		return (ENXIO);
530 	if (setup_pio(dev, "pio-send", &sc->pio_send) != 0)
531 		return (ENXIO);
532 	if (setup_pio(dev, "pio-recv", &sc->pio_recv) != 0)
533 		return (ENXIO);
534 
535 	sc->cdev = make_dev(&beri_cdevsw, 0, UID_ROOT, GID_WHEEL,
536 	    S_IRWXU, "beri_vtblk");
537 	if (sc->cdev == NULL) {
538 		device_printf(dev, "Failed to create character device.\n");
539 		return (ENXIO);
540 	}
541 
542 	sc->cdev->si_drv1 = sc;
543 	return (0);
544 }
545 
546 static device_method_t beri_vtblk_methods[] = {
547 	DEVMETHOD(device_probe,		beri_vtblk_probe),
548 	DEVMETHOD(device_attach,	beri_vtblk_attach),
549 	{ 0, 0 }
550 };
551 
552 static driver_t beri_vtblk_driver = {
553 	"beri_vtblk",
554 	beri_vtblk_methods,
555 	sizeof(struct beri_vtblk_softc),
556 };
557 
558 static devclass_t beri_vtblk_devclass;
559 
560 DRIVER_MODULE(beri_vtblk, simplebus, beri_vtblk_driver,
561     beri_vtblk_devclass, 0, 0);
562