xref: /netbsd-src/sys/dev/pci/ld_virtio.c (revision 796c32c94f6e154afc9de0f63da35c91bb739b45)
1 /*	$NetBSD: ld_virtio.c,v 1.16 2017/08/09 16:44:40 mlelstv 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: ld_virtio.c,v 1.16 2017/08/09 16:44:40 mlelstv Exp $");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/buf.h>
35 #include <sys/bufq.h>
36 #include <sys/bus.h>
37 #include <sys/device.h>
38 #include <sys/disk.h>
39 #include <sys/mutex.h>
40 #include <sys/module.h>
41 
42 #include <dev/pci/pcidevs.h>
43 #include <dev/pci/pcireg.h>
44 #include <dev/pci/pcivar.h>
45 
46 #include <dev/ldvar.h>
47 #include <dev/pci/virtioreg.h>
48 #include <dev/pci/virtiovar.h>
49 
50 #include "ioconf.h"
51 
52 /*
53  * ld_virtioreg:
54  */
55 /* Configuration registers */
56 #define VIRTIO_BLK_CONFIG_CAPACITY	0 /* 64bit */
57 #define VIRTIO_BLK_CONFIG_SIZE_MAX	8 /* 32bit */
58 #define VIRTIO_BLK_CONFIG_SEG_MAX	12 /* 32bit */
59 #define VIRTIO_BLK_CONFIG_GEOMETRY_C	16 /* 16bit */
60 #define VIRTIO_BLK_CONFIG_GEOMETRY_H	18 /* 8bit */
61 #define VIRTIO_BLK_CONFIG_GEOMETRY_S	19 /* 8bit */
62 #define VIRTIO_BLK_CONFIG_BLK_SIZE	20 /* 32bit */
63 
64 /* Feature bits */
65 #define VIRTIO_BLK_F_BARRIER	(1<<0)
66 #define VIRTIO_BLK_F_SIZE_MAX	(1<<1)
67 #define VIRTIO_BLK_F_SEG_MAX	(1<<2)
68 #define VIRTIO_BLK_F_GEOMETRY	(1<<4)
69 #define VIRTIO_BLK_F_RO		(1<<5)
70 #define VIRTIO_BLK_F_BLK_SIZE	(1<<6)
71 #define VIRTIO_BLK_F_SCSI	(1<<7)
72 #define VIRTIO_BLK_F_FLUSH	(1<<9)
73 
74 /*
75  * Each block request uses at least two segments - one for the header
76  * and one for the status.
77 */
78 #define	VIRTIO_BLK_MIN_SEGMENTS	2
79 
80 #define VIRTIO_BLK_FLAG_BITS \
81 	VIRTIO_COMMON_FLAG_BITS \
82 	"\x0a""FLUSH" \
83 	"\x08""SCSI" \
84 	"\x07""BLK_SIZE" \
85 	"\x06""RO" \
86 	"\x05""GEOMETRY" \
87 	"\x03""SEG_MAX" \
88 	"\x02""SIZE_MAX" \
89 	"\x01""BARRIER"
90 
91 /* Command */
92 #define VIRTIO_BLK_T_IN		0
93 #define VIRTIO_BLK_T_OUT	1
94 #define VIRTIO_BLK_T_BARRIER	0x80000000
95 
96 /* Status */
97 #define VIRTIO_BLK_S_OK		0
98 #define VIRTIO_BLK_S_IOERR	1
99 
100 /* Request header structure */
101 struct virtio_blk_req_hdr {
102 	uint32_t	type;	/* VIRTIO_BLK_T_* */
103 	uint32_t	ioprio;
104 	uint64_t	sector;
105 } __packed;
106 /* 512*virtio_blk_req_hdr.sector byte payload and 1 byte status follows */
107 
108 
109 /*
110  * ld_virtiovar:
111  */
112 struct virtio_blk_req {
113 	struct virtio_blk_req_hdr	vr_hdr;
114 	uint8_t				vr_status;
115 	struct buf			*vr_bp;
116 	bus_dmamap_t			vr_cmdsts;
117 	bus_dmamap_t			vr_payload;
118 };
119 
120 struct ld_virtio_softc {
121 	struct ld_softc		sc_ld;
122 	device_t		sc_dev;
123 
124 	struct virtio_softc	*sc_virtio;
125 	struct virtqueue	sc_vq;
126 
127 	struct virtio_blk_req	*sc_reqs;
128 	bus_dma_segment_t	sc_reqs_seg;
129 
130 	int			sc_readonly;
131 };
132 
133 static int	ld_virtio_match(device_t, cfdata_t, void *);
134 static void	ld_virtio_attach(device_t, device_t, void *);
135 static int	ld_virtio_detach(device_t, int);
136 
137 CFATTACH_DECL_NEW(ld_virtio, sizeof(struct ld_virtio_softc),
138     ld_virtio_match, ld_virtio_attach, ld_virtio_detach, NULL);
139 
140 static int
141 ld_virtio_match(device_t parent, cfdata_t match, void *aux)
142 {
143 	struct virtio_attach_args *va = aux;
144 
145 	if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_BLOCK)
146 		return 1;
147 
148 	return 0;
149 }
150 
151 static int ld_virtio_vq_done(struct virtqueue *);
152 static int ld_virtio_dump(struct ld_softc *, void *, int, int);
153 static int ld_virtio_start(struct ld_softc *, struct buf *);
154 
155 static int
156 ld_virtio_alloc_reqs(struct ld_virtio_softc *sc, int qsize)
157 {
158 	int allocsize, r, rsegs, i;
159 	struct ld_softc *ld = &sc->sc_ld;
160 	void *vaddr;
161 
162 	allocsize = sizeof(struct virtio_blk_req) * qsize;
163 	r = bus_dmamem_alloc(virtio_dmat(sc->sc_virtio), allocsize, 0, 0,
164 			     &sc->sc_reqs_seg, 1, &rsegs, BUS_DMA_NOWAIT);
165 	if (r != 0) {
166 		aprint_error_dev(sc->sc_dev,
167 				 "DMA memory allocation failed, size %d, "
168 				 "error code %d\n", allocsize, r);
169 		goto err_none;
170 	}
171 	r = bus_dmamem_map(virtio_dmat(sc->sc_virtio),
172 			   &sc->sc_reqs_seg, 1, allocsize,
173 			   &vaddr, BUS_DMA_NOWAIT);
174 	if (r != 0) {
175 		aprint_error_dev(sc->sc_dev,
176 				 "DMA memory map failed, "
177 				 "error code %d\n", r);
178 		goto err_dmamem_alloc;
179 	}
180 	sc->sc_reqs = vaddr;
181 	memset(vaddr, 0, allocsize);
182 	for (i = 0; i < qsize; i++) {
183 		struct virtio_blk_req *vr = &sc->sc_reqs[i];
184 		r = bus_dmamap_create(virtio_dmat(sc->sc_virtio),
185 				      offsetof(struct virtio_blk_req, vr_bp),
186 				      1,
187 				      offsetof(struct virtio_blk_req, vr_bp),
188 				      0,
189 				      BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
190 				      &vr->vr_cmdsts);
191 		if (r != 0) {
192 			aprint_error_dev(sc->sc_dev,
193 					 "command dmamap creation failed, "
194 					 "error code %d\n", r);
195 			goto err_reqs;
196 		}
197 		r = bus_dmamap_load(virtio_dmat(sc->sc_virtio), vr->vr_cmdsts,
198 				    &vr->vr_hdr,
199 				    offsetof(struct virtio_blk_req, vr_bp),
200 				    NULL, BUS_DMA_NOWAIT);
201 		if (r != 0) {
202 			aprint_error_dev(sc->sc_dev,
203 					 "command dmamap load failed, "
204 					 "error code %d\n", r);
205 			goto err_reqs;
206 		}
207 		r = bus_dmamap_create(virtio_dmat(sc->sc_virtio),
208 				      ld->sc_maxxfer,
209 				      (ld->sc_maxxfer / NBPG) +
210 				      VIRTIO_BLK_MIN_SEGMENTS,
211 				      ld->sc_maxxfer,
212 				      0,
213 				      BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
214 				      &vr->vr_payload);
215 		if (r != 0) {
216 			aprint_error_dev(sc->sc_dev,
217 					 "payload dmamap creation failed, "
218 					 "error code %d\n", r);
219 			goto err_reqs;
220 		}
221 	}
222 	return 0;
223 
224 err_reqs:
225 	for (i = 0; i < qsize; i++) {
226 		struct virtio_blk_req *vr = &sc->sc_reqs[i];
227 		if (vr->vr_cmdsts) {
228 			bus_dmamap_destroy(virtio_dmat(sc->sc_virtio),
229 					   vr->vr_cmdsts);
230 			vr->vr_cmdsts = 0;
231 		}
232 		if (vr->vr_payload) {
233 			bus_dmamap_destroy(virtio_dmat(sc->sc_virtio),
234 					   vr->vr_payload);
235 			vr->vr_payload = 0;
236 		}
237 	}
238 	bus_dmamem_unmap(virtio_dmat(sc->sc_virtio), sc->sc_reqs, allocsize);
239 err_dmamem_alloc:
240 	bus_dmamem_free(virtio_dmat(sc->sc_virtio), &sc->sc_reqs_seg, 1);
241 err_none:
242 	return -1;
243 }
244 
245 static void
246 ld_virtio_attach(device_t parent, device_t self, void *aux)
247 {
248 	struct ld_virtio_softc *sc = device_private(self);
249 	struct ld_softc *ld = &sc->sc_ld;
250 	struct virtio_softc *vsc = device_private(parent);
251 	uint32_t features;
252 	int qsize, maxxfersize, maxnsegs;
253 
254 	if (virtio_child(vsc) != NULL) {
255 		aprint_normal(": child already attached for %s; "
256 			      "something wrong...\n", device_xname(parent));
257 		return;
258 	}
259 
260 	sc->sc_dev = self;
261 	sc->sc_virtio = vsc;
262 
263 	virtio_child_attach_start(vsc, self, IPL_BIO, &sc->sc_vq,
264 	    NULL, virtio_vq_intr, 0,
265 	    (VIRTIO_BLK_F_SIZE_MAX | VIRTIO_BLK_F_SEG_MAX |
266 	     VIRTIO_BLK_F_GEOMETRY | VIRTIO_BLK_F_RO | VIRTIO_BLK_F_BLK_SIZE),
267 	    VIRTIO_BLK_FLAG_BITS);
268 
269 	features = virtio_features(vsc);
270 
271 	if (features & VIRTIO_BLK_F_RO)
272 		sc->sc_readonly = 1;
273 	else
274 		sc->sc_readonly = 0;
275 
276 	if (features & VIRTIO_BLK_F_BLK_SIZE) {
277 		ld->sc_secsize = virtio_read_device_config_4(vsc,
278 					VIRTIO_BLK_CONFIG_BLK_SIZE);
279 	} else
280 		ld->sc_secsize = 512;
281 
282 	/* At least genfs_io assumes maxxfer == MAXPHYS. */
283 	if (features & VIRTIO_BLK_F_SIZE_MAX) {
284 		maxxfersize = virtio_read_device_config_4(vsc,
285 		    VIRTIO_BLK_CONFIG_SIZE_MAX);
286 		if (maxxfersize < MAXPHYS) {
287 			aprint_error_dev(sc->sc_dev,
288 			    "Too small SIZE_MAX %dK minimum is %dK\n",
289 			    maxxfersize / 1024, MAXPHYS / 1024);
290 			// goto err;
291 			maxxfersize = MAXPHYS;
292 		} else if (maxxfersize > MAXPHYS) {
293 			aprint_normal_dev(sc->sc_dev,
294 			    "Clip SEG_MAX from %dK to %dK\n",
295 			    maxxfersize / 1024,
296 			    MAXPHYS / 1024);
297 			maxxfersize = MAXPHYS;
298 		}
299 	} else
300 		maxxfersize = MAXPHYS;
301 
302 	if (features & VIRTIO_BLK_F_SEG_MAX) {
303 		maxnsegs = virtio_read_device_config_4(vsc,
304 		    VIRTIO_BLK_CONFIG_SEG_MAX);
305 		if (maxnsegs < VIRTIO_BLK_MIN_SEGMENTS) {
306 			aprint_error_dev(sc->sc_dev,
307 			    "Too small SEG_MAX %d minimum is %d\n",
308 			    maxnsegs, VIRTIO_BLK_MIN_SEGMENTS);
309 			maxnsegs = maxxfersize / NBPG;
310 			// goto err;
311 		}
312 	} else
313 		maxnsegs = maxxfersize / NBPG;
314 
315 	/* 2 for the minimum size */
316 	maxnsegs += VIRTIO_BLK_MIN_SEGMENTS;
317 
318 	if (virtio_alloc_vq(vsc, &sc->sc_vq, 0, maxxfersize, maxnsegs,
319 	    "I/O request") != 0) {
320 		goto err;
321 	}
322 	qsize = sc->sc_vq.vq_num;
323 	sc->sc_vq.vq_done = ld_virtio_vq_done;
324 
325 	if (virtio_child_attach_finish(vsc) != 0)
326 		goto err;
327 
328 	ld->sc_dv = self;
329 	ld->sc_secperunit = virtio_read_device_config_8(vsc,
330 				VIRTIO_BLK_CONFIG_CAPACITY);
331 	ld->sc_maxxfer = maxxfersize;
332 	if (features & VIRTIO_BLK_F_GEOMETRY) {
333 		ld->sc_ncylinders = virtio_read_device_config_2(vsc,
334 					VIRTIO_BLK_CONFIG_GEOMETRY_C);
335 		ld->sc_nheads     = virtio_read_device_config_1(vsc,
336 					VIRTIO_BLK_CONFIG_GEOMETRY_H);
337 		ld->sc_nsectors   = virtio_read_device_config_1(vsc,
338 					VIRTIO_BLK_CONFIG_GEOMETRY_S);
339 	}
340 	ld->sc_maxqueuecnt = qsize;
341 
342 	if (ld_virtio_alloc_reqs(sc, qsize) < 0)
343 		goto err;
344 
345 	ld->sc_dump = ld_virtio_dump;
346 	ld->sc_start = ld_virtio_start;
347 
348 	ld->sc_flags = LDF_ENABLED | LDF_MPSAFE;
349 	ldattach(ld, BUFQ_DISK_DEFAULT_STRAT);
350 
351 	return;
352 
353 err:
354 	virtio_child_attach_failed(vsc);
355 	return;
356 }
357 
358 static int
359 ld_virtio_start(struct ld_softc *ld, struct buf *bp)
360 {
361 	/* splbio */
362 	struct ld_virtio_softc *sc = device_private(ld->sc_dv);
363 	struct virtio_softc *vsc = sc->sc_virtio;
364 	struct virtqueue *vq = &sc->sc_vq;
365 	struct virtio_blk_req *vr;
366 	int r;
367 	int isread = (bp->b_flags & B_READ);
368 	int slot;
369 
370 	if (sc->sc_readonly && !isread)
371 		return EIO;
372 
373 	r = virtio_enqueue_prep(vsc, vq, &slot);
374 	if (r != 0)
375 		return r;
376 
377 	vr = &sc->sc_reqs[slot];
378 	KASSERT(vr->vr_bp == NULL);
379 
380 	r = bus_dmamap_load(virtio_dmat(vsc), vr->vr_payload,
381 			    bp->b_data, bp->b_bcount, NULL,
382 			    ((isread?BUS_DMA_READ:BUS_DMA_WRITE)
383 			     |BUS_DMA_NOWAIT));
384 	if (r != 0) {
385 		aprint_error_dev(sc->sc_dev,
386 		    "payload dmamap failed, error code %d\n", r);
387 		virtio_enqueue_abort(vsc, vq, slot);
388 		return r;
389 	}
390 
391 	r = virtio_enqueue_reserve(vsc, vq, slot, vr->vr_payload->dm_nsegs +
392 	    VIRTIO_BLK_MIN_SEGMENTS);
393 	if (r != 0) {
394 		bus_dmamap_unload(virtio_dmat(vsc), vr->vr_payload);
395 		return r;
396 	}
397 
398 	vr->vr_bp = bp;
399 	vr->vr_hdr.type = isread?VIRTIO_BLK_T_IN:VIRTIO_BLK_T_OUT;
400 	vr->vr_hdr.ioprio = 0;
401 	vr->vr_hdr.sector = bp->b_rawblkno * sc->sc_ld.sc_secsize / 512;
402 
403 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
404 			0, sizeof(struct virtio_blk_req_hdr),
405 			BUS_DMASYNC_PREWRITE);
406 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_payload,
407 			0, bp->b_bcount,
408 			isread?BUS_DMASYNC_PREREAD:BUS_DMASYNC_PREWRITE);
409 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
410 			offsetof(struct virtio_blk_req, vr_status),
411 			sizeof(uint8_t),
412 			BUS_DMASYNC_PREREAD);
413 
414 	virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
415 			 0, sizeof(struct virtio_blk_req_hdr),
416 			 true);
417 	virtio_enqueue(vsc, vq, slot, vr->vr_payload, !isread);
418 	virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
419 			 offsetof(struct virtio_blk_req, vr_status),
420 			 sizeof(uint8_t),
421 			 false);
422 	virtio_enqueue_commit(vsc, vq, slot, true);
423 
424 	return 0;
425 }
426 
427 static void
428 ld_virtio_vq_done1(struct ld_virtio_softc *sc, struct virtio_softc *vsc,
429 		   struct virtqueue *vq, int slot)
430 {
431 	struct virtio_blk_req *vr = &sc->sc_reqs[slot];
432 	struct buf *bp = vr->vr_bp;
433 
434 	vr->vr_bp = NULL;
435 
436 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
437 			0, sizeof(struct virtio_blk_req_hdr),
438 			BUS_DMASYNC_POSTWRITE);
439 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_payload,
440 			0, bp->b_bcount,
441 			(bp->b_flags & B_READ)?BUS_DMASYNC_POSTREAD
442 					      :BUS_DMASYNC_POSTWRITE);
443 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
444 			sizeof(struct virtio_blk_req_hdr), sizeof(uint8_t),
445 			BUS_DMASYNC_POSTREAD);
446 
447 	if (vr->vr_status != VIRTIO_BLK_S_OK) {
448 		bp->b_error = EIO;
449 		bp->b_resid = bp->b_bcount;
450 	} else {
451 		bp->b_error = 0;
452 		bp->b_resid = 0;
453 	}
454 
455 	virtio_dequeue_commit(vsc, vq, slot);
456 
457 	lddone(&sc->sc_ld, bp);
458 }
459 
460 static int
461 ld_virtio_vq_done(struct virtqueue *vq)
462 {
463 	struct virtio_softc *vsc = vq->vq_owner;
464 	struct ld_virtio_softc *sc = device_private(virtio_child(vsc));
465 	int r = 0;
466 	int slot;
467 
468 again:
469 	if (virtio_dequeue(vsc, vq, &slot, NULL))
470 		return r;
471 	r = 1;
472 
473 	ld_virtio_vq_done1(sc, vsc, vq, slot);
474 	goto again;
475 }
476 
477 static int
478 ld_virtio_dump(struct ld_softc *ld, void *data, int blkno, int blkcnt)
479 {
480 	struct ld_virtio_softc *sc = device_private(ld->sc_dv);
481 	struct virtio_softc *vsc = sc->sc_virtio;
482 	struct virtqueue *vq = &sc->sc_vq;
483 	struct virtio_blk_req *vr;
484 	int slot, r;
485 
486 	if (sc->sc_readonly)
487 		return EIO;
488 
489 	r = virtio_enqueue_prep(vsc, vq, &slot);
490 	if (r != 0) {
491 		if (r == EAGAIN) { /* no free slot; dequeue first */
492 			delay(100);
493 			ld_virtio_vq_done(vq);
494 			r = virtio_enqueue_prep(vsc, vq, &slot);
495 			if (r != 0)
496 				return r;
497 		}
498 		return r;
499 	}
500 	vr = &sc->sc_reqs[slot];
501 	r = bus_dmamap_load(virtio_dmat(vsc), vr->vr_payload,
502 			    data, blkcnt*ld->sc_secsize, NULL,
503 			    BUS_DMA_WRITE|BUS_DMA_NOWAIT);
504 	if (r != 0)
505 		return r;
506 
507 	r = virtio_enqueue_reserve(vsc, vq, slot, vr->vr_payload->dm_nsegs +
508 	    VIRTIO_BLK_MIN_SEGMENTS);
509 	if (r != 0) {
510 		bus_dmamap_unload(virtio_dmat(vsc), vr->vr_payload);
511 		return r;
512 	}
513 
514 	vr->vr_bp = (void*)0xdeadbeef;
515 	vr->vr_hdr.type = VIRTIO_BLK_T_OUT;
516 	vr->vr_hdr.ioprio = 0;
517 	vr->vr_hdr.sector = (daddr_t) blkno * ld->sc_secsize / 512;
518 
519 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
520 			0, sizeof(struct virtio_blk_req_hdr),
521 			BUS_DMASYNC_PREWRITE);
522 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_payload,
523 			0, blkcnt*ld->sc_secsize,
524 			BUS_DMASYNC_PREWRITE);
525 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
526 			offsetof(struct virtio_blk_req, vr_status),
527 			sizeof(uint8_t),
528 			BUS_DMASYNC_PREREAD);
529 
530 	virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
531 			 0, sizeof(struct virtio_blk_req_hdr),
532 			 true);
533 	virtio_enqueue(vsc, vq, slot, vr->vr_payload, true);
534 	virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
535 			 offsetof(struct virtio_blk_req, vr_status),
536 			 sizeof(uint8_t),
537 			 false);
538 	virtio_enqueue_commit(vsc, vq, slot, true);
539 
540 	for ( ; ; ) {
541 		int dslot;
542 
543 		r = virtio_dequeue(vsc, vq, &dslot, NULL);
544 		if (r != 0)
545 			continue;
546 		if (dslot != slot) {
547 			ld_virtio_vq_done1(sc, vsc, vq, dslot);
548 			continue;
549 		} else
550 			break;
551 	}
552 
553 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
554 			0, sizeof(struct virtio_blk_req_hdr),
555 			BUS_DMASYNC_POSTWRITE);
556 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_payload,
557 			0, blkcnt*ld->sc_secsize,
558 			BUS_DMASYNC_POSTWRITE);
559 	bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
560 			offsetof(struct virtio_blk_req, vr_status),
561 			sizeof(uint8_t),
562 			BUS_DMASYNC_POSTREAD);
563 	if (vr->vr_status == VIRTIO_BLK_S_OK)
564 		r = 0;
565 	else
566 		r = EIO;
567 	virtio_dequeue_commit(vsc, vq, slot);
568 
569 	return r;
570 }
571 
572 static int
573 ld_virtio_detach(device_t self, int flags)
574 {
575 	struct ld_virtio_softc *sc = device_private(self);
576 	struct ld_softc *ld = &sc->sc_ld;
577 	bus_dma_tag_t dmat = virtio_dmat(sc->sc_virtio);
578 	int r, i, qsize;
579 
580 	qsize = sc->sc_vq.vq_num;
581 	r = ldbegindetach(ld, flags);
582 	if (r != 0)
583 		return r;
584 	virtio_reset(sc->sc_virtio);
585 	virtio_free_vq(sc->sc_virtio, &sc->sc_vq);
586 
587 	for (i = 0; i < qsize; i++) {
588 		bus_dmamap_destroy(dmat,
589 				   sc->sc_reqs[i].vr_cmdsts);
590 		bus_dmamap_destroy(dmat,
591 				   sc->sc_reqs[i].vr_payload);
592 	}
593 	bus_dmamem_unmap(dmat, sc->sc_reqs,
594 			 sizeof(struct virtio_blk_req) * qsize);
595 	bus_dmamem_free(dmat, &sc->sc_reqs_seg, 1);
596 
597 	ldenddetach(ld);
598 
599 	virtio_child_detach(sc->sc_virtio);
600 
601 	return 0;
602 }
603 
604 MODULE(MODULE_CLASS_DRIVER, ld_virtio, "ld,virtio");
605 
606 #ifdef _MODULE
607 /*
608  * XXX Don't allow ioconf.c to redefine the "struct cfdriver ld_cd"
609  * XXX it will be defined in the common-code module
610  */
611 #undef  CFDRIVER_DECL
612 #define CFDRIVER_DECL(name, class, attr)
613 #include "ioconf.c"
614 #endif
615 
616 static int
617 ld_virtio_modcmd(modcmd_t cmd, void *opaque)
618 {
619 #ifdef _MODULE
620 	/*
621 	 * We ignore the cfdriver_vec[] that ioconf provides, since
622 	 * the cfdrivers are attached already.
623 	 */
624 	static struct cfdriver * const no_cfdriver_vec[] = { NULL };
625 #endif
626 	int error = 0;
627 
628 #ifdef _MODULE
629 	switch (cmd) {
630 	case MODULE_CMD_INIT:
631 		error = config_init_component(no_cfdriver_vec,
632 		    cfattach_ioconf_ld_virtio, cfdata_ioconf_ld_virtio);
633 		break;
634 	case MODULE_CMD_FINI:
635 		error = config_fini_component(no_cfdriver_vec,
636 		    cfattach_ioconf_ld_virtio, cfdata_ioconf_ld_virtio);
637 		break;
638 	default:
639 		error = ENOTTY;
640 		break;
641 	}
642 #endif
643 
644 	return error;
645 }
646