ld_virtio.c revision 1.6 1 /* $NetBSD: ld_virtio.c,v 1.6 2014/07/22 01:55:54 ozaki-r 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 1.6 2014/07/22 01:55:54 ozaki-r 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/bus.h>
36 #include <sys/device.h>
37 #include <sys/disk.h>
38 #include <sys/mutex.h>
39 #include <sys/rnd.h>
40
41 #include <dev/pci/pcidevs.h>
42 #include <dev/pci/pcireg.h>
43 #include <dev/pci/pcivar.h>
44
45 #include <dev/ldvar.h>
46 #include <dev/pci/virtioreg.h>
47 #include <dev/pci/virtiovar.h>
48
49 /*
50 * ld_virtioreg:
51 */
52 /* Configuration registers */
53 #define VIRTIO_BLK_CONFIG_CAPACITY 0 /* 64bit */
54 #define VIRTIO_BLK_CONFIG_SIZE_MAX 8 /* 32bit */
55 #define VIRTIO_BLK_CONFIG_SEG_MAX 12 /* 32bit */
56 #define VIRTIO_BLK_CONFIG_GEOMETRY_C 16 /* 16bit */
57 #define VIRTIO_BLK_CONFIG_GEOMETRY_H 18 /* 8bit */
58 #define VIRTIO_BLK_CONFIG_GEOMETRY_S 19 /* 8bit */
59 #define VIRTIO_BLK_CONFIG_BLK_SIZE 20 /* 32bit */
60
61 /* Feature bits */
62 #define VIRTIO_BLK_F_BARRIER (1<<0)
63 #define VIRTIO_BLK_F_SIZE_MAX (1<<1)
64 #define VIRTIO_BLK_F_SEG_MAX (1<<2)
65 #define VIRTIO_BLK_F_GEOMETRY (1<<4)
66 #define VIRTIO_BLK_F_RO (1<<5)
67 #define VIRTIO_BLK_F_BLK_SIZE (1<<6)
68 #define VIRTIO_BLK_F_SCSI (1<<7)
69 #define VIRTIO_BLK_F_FLUSH (1<<9)
70
71 /* Command */
72 #define VIRTIO_BLK_T_IN 0
73 #define VIRTIO_BLK_T_OUT 1
74 #define VIRTIO_BLK_T_BARRIER 0x80000000
75
76 /* Status */
77 #define VIRTIO_BLK_S_OK 0
78 #define VIRTIO_BLK_S_IOERR 1
79
80 /* Request header structure */
81 struct virtio_blk_req_hdr {
82 uint32_t type; /* VIRTIO_BLK_T_* */
83 uint32_t ioprio;
84 uint64_t sector;
85 } __packed;
86 /* 512*virtio_blk_req_hdr.sector byte payload and 1 byte status follows */
87
88
89 /*
90 * ld_virtiovar:
91 */
92 struct virtio_blk_req {
93 struct virtio_blk_req_hdr vr_hdr;
94 uint8_t vr_status;
95 struct buf *vr_bp;
96 bus_dmamap_t vr_cmdsts;
97 bus_dmamap_t vr_payload;
98 };
99
100 struct ld_virtio_softc {
101 struct ld_softc sc_ld;
102 device_t sc_dev;
103
104 struct virtio_softc *sc_virtio;
105 struct virtqueue sc_vq[1];
106
107 struct virtio_blk_req *sc_reqs;
108 bus_dma_segment_t sc_reqs_segs[1];
109
110 kmutex_t sc_lock;
111
112 int sc_readonly;
113 };
114
115 static int ld_virtio_match(device_t, cfdata_t, void *);
116 static void ld_virtio_attach(device_t, device_t, void *);
117 static int ld_virtio_detach(device_t, int);
118
119 CFATTACH_DECL_NEW(ld_virtio, sizeof(struct ld_virtio_softc),
120 ld_virtio_match, ld_virtio_attach, ld_virtio_detach, NULL);
121
122 static int
123 ld_virtio_match(device_t parent, cfdata_t match, void *aux)
124 {
125 struct virtio_softc *va = aux;
126
127 if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_BLOCK)
128 return 1;
129
130 return 0;
131 }
132
133 static int ld_virtio_vq_done(struct virtqueue *);
134 static int ld_virtio_dump(struct ld_softc *, void *, int, int);
135 static int ld_virtio_start(struct ld_softc *, struct buf *);
136
137 static int
138 ld_virtio_alloc_reqs(struct ld_virtio_softc *sc, int qsize)
139 {
140 int allocsize, r, rsegs, i;
141 struct ld_softc *ld = &sc->sc_ld;
142 void *vaddr;
143
144 allocsize = sizeof(struct virtio_blk_req) * qsize;
145 r = bus_dmamem_alloc(sc->sc_virtio->sc_dmat, allocsize, 0, 0,
146 &sc->sc_reqs_segs[0], 1, &rsegs, BUS_DMA_NOWAIT);
147 if (r != 0) {
148 aprint_error_dev(sc->sc_dev,
149 "DMA memory allocation failed, size %d, "
150 "error code %d\n", allocsize, r);
151 goto err_none;
152 }
153 r = bus_dmamem_map(sc->sc_virtio->sc_dmat,
154 &sc->sc_reqs_segs[0], 1, allocsize,
155 &vaddr, BUS_DMA_NOWAIT);
156 if (r != 0) {
157 aprint_error_dev(sc->sc_dev,
158 "DMA memory map failed, "
159 "error code %d\n", r);
160 goto err_dmamem_alloc;
161 }
162 sc->sc_reqs = vaddr;
163 memset(vaddr, 0, allocsize);
164 for (i = 0; i < qsize; i++) {
165 struct virtio_blk_req *vr = &sc->sc_reqs[i];
166 r = bus_dmamap_create(sc->sc_virtio->sc_dmat,
167 offsetof(struct virtio_blk_req, vr_bp),
168 1,
169 offsetof(struct virtio_blk_req, vr_bp),
170 0,
171 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
172 &vr->vr_cmdsts);
173 if (r != 0) {
174 aprint_error_dev(sc->sc_dev,
175 "command dmamap creation failed, "
176 "error code %d\n", r);
177 goto err_reqs;
178 }
179 r = bus_dmamap_load(sc->sc_virtio->sc_dmat, vr->vr_cmdsts,
180 &vr->vr_hdr,
181 offsetof(struct virtio_blk_req, vr_bp),
182 NULL, BUS_DMA_NOWAIT);
183 if (r != 0) {
184 aprint_error_dev(sc->sc_dev,
185 "command dmamap load failed, "
186 "error code %d\n", r);
187 goto err_reqs;
188 }
189 r = bus_dmamap_create(sc->sc_virtio->sc_dmat,
190 ld->sc_maxxfer,
191 (ld->sc_maxxfer / NBPG) + 2,
192 ld->sc_maxxfer,
193 0,
194 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
195 &vr->vr_payload);
196 if (r != 0) {
197 aprint_error_dev(sc->sc_dev,
198 "payload dmamap creation failed, "
199 "error code %d\n", r);
200 goto err_reqs;
201 }
202 }
203 return 0;
204
205 err_reqs:
206 for (i = 0; i < qsize; i++) {
207 struct virtio_blk_req *vr = &sc->sc_reqs[i];
208 if (vr->vr_cmdsts) {
209 bus_dmamap_destroy(sc->sc_virtio->sc_dmat,
210 vr->vr_cmdsts);
211 vr->vr_cmdsts = 0;
212 }
213 if (vr->vr_payload) {
214 bus_dmamap_destroy(sc->sc_virtio->sc_dmat,
215 vr->vr_payload);
216 vr->vr_payload = 0;
217 }
218 }
219 bus_dmamem_unmap(sc->sc_virtio->sc_dmat, sc->sc_reqs, allocsize);
220 err_dmamem_alloc:
221 bus_dmamem_free(sc->sc_virtio->sc_dmat, &sc->sc_reqs_segs[0], 1);
222 err_none:
223 return -1;
224 }
225
226 static void
227 ld_virtio_attach(device_t parent, device_t self, void *aux)
228 {
229 struct ld_virtio_softc *sc = device_private(self);
230 struct ld_softc *ld = &sc->sc_ld;
231 struct virtio_softc *vsc = device_private(parent);
232 uint32_t features;
233 int qsize, maxxfersize;
234
235 if (vsc->sc_child != NULL) {
236 aprint_normal(": child already attached for %s; "
237 "something wrong...\n",
238 device_xname(parent));
239 return;
240 }
241 aprint_normal("\n");
242 aprint_naive("\n");
243
244 sc->sc_dev = self;
245 sc->sc_virtio = vsc;
246
247 vsc->sc_child = self;
248 vsc->sc_ipl = IPL_BIO;
249 vsc->sc_vqs = &sc->sc_vq[0];
250 vsc->sc_nvqs = 1;
251 vsc->sc_config_change = 0;
252 vsc->sc_intrhand = virtio_vq_intr;
253 vsc->sc_flags = 0;
254
255 features = virtio_negotiate_features(vsc,
256 (VIRTIO_BLK_F_SIZE_MAX |
257 VIRTIO_BLK_F_SEG_MAX |
258 VIRTIO_BLK_F_GEOMETRY |
259 VIRTIO_BLK_F_RO |
260 VIRTIO_BLK_F_BLK_SIZE));
261 if (features & VIRTIO_BLK_F_RO)
262 sc->sc_readonly = 1;
263 else
264 sc->sc_readonly = 0;
265
266 ld->sc_secsize = 512;
267 if (features & VIRTIO_BLK_F_BLK_SIZE) {
268 ld->sc_secsize = virtio_read_device_config_4(vsc,
269 VIRTIO_BLK_CONFIG_BLK_SIZE);
270 }
271 maxxfersize = MAXPHYS;
272 #if 0 /* At least genfs_io assumes maxxfer == MAXPHYS. */
273 if (features & VIRTIO_BLK_F_SEG_MAX) {
274 maxxfersize = virtio_read_device_config_4(vsc,
275 VIRTIO_BLK_CONFIG_SEG_MAX)
276 * ld->sc_secsize;
277 if (maxxfersize > MAXPHYS)
278 maxxfersize = MAXPHYS;
279 }
280 #endif
281
282 if (virtio_alloc_vq(vsc, &sc->sc_vq[0], 0,
283 maxxfersize, maxxfersize / NBPG + 2,
284 "I/O request") != 0) {
285 goto err;
286 }
287 qsize = sc->sc_vq[0].vq_num;
288 sc->sc_vq[0].vq_done = ld_virtio_vq_done;
289
290 ld->sc_dv = self;
291 ld->sc_secperunit = virtio_read_device_config_8(vsc,
292 VIRTIO_BLK_CONFIG_CAPACITY);
293 ld->sc_maxxfer = maxxfersize;
294 if (features & VIRTIO_BLK_F_GEOMETRY) {
295 ld->sc_ncylinders = virtio_read_device_config_2(vsc,
296 VIRTIO_BLK_CONFIG_GEOMETRY_C);
297 ld->sc_nheads = virtio_read_device_config_1(vsc,
298 VIRTIO_BLK_CONFIG_GEOMETRY_H);
299 ld->sc_nsectors = virtio_read_device_config_1(vsc,
300 VIRTIO_BLK_CONFIG_GEOMETRY_S);
301 }
302 ld->sc_maxqueuecnt = qsize;
303
304 if (ld_virtio_alloc_reqs(sc, qsize) < 0)
305 goto err;
306
307 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_BIO);
308
309 ld->sc_dump = ld_virtio_dump;
310 ld->sc_flush = NULL;
311 ld->sc_start = ld_virtio_start;
312
313 ld->sc_flags = LDF_ENABLED;
314 ldattach(ld);
315
316 return;
317
318 err:
319 vsc->sc_child = (void*)1;
320 return;
321 }
322
323 static int
324 ld_virtio_start(struct ld_softc *ld, struct buf *bp)
325 {
326 /* splbio */
327 struct ld_virtio_softc *sc = device_private(ld->sc_dv);
328 struct virtio_softc *vsc = sc->sc_virtio;
329 struct virtqueue *vq = &sc->sc_vq[0];
330 struct virtio_blk_req *vr;
331 int r;
332 int isread = (bp->b_flags & B_READ);
333 int slot;
334
335 if (sc->sc_readonly && !isread)
336 return EIO;
337
338 r = virtio_enqueue_prep(vsc, vq, &slot);
339 if (r != 0)
340 return r;
341 vr = &sc->sc_reqs[slot];
342 r = bus_dmamap_load(vsc->sc_dmat, vr->vr_payload,
343 bp->b_data, bp->b_bcount, NULL,
344 ((isread?BUS_DMA_READ:BUS_DMA_WRITE)
345 |BUS_DMA_NOWAIT));
346 if (r != 0)
347 return r;
348
349 r = virtio_enqueue_reserve(vsc, vq, slot, vr->vr_payload->dm_nsegs + 2);
350 if (r != 0) {
351 bus_dmamap_unload(vsc->sc_dmat, vr->vr_payload);
352 return r;
353 }
354
355 vr->vr_bp = bp;
356 vr->vr_hdr.type = isread?VIRTIO_BLK_T_IN:VIRTIO_BLK_T_OUT;
357 vr->vr_hdr.ioprio = 0;
358 vr->vr_hdr.sector = bp->b_rawblkno * sc->sc_ld.sc_secsize / 512;
359
360 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
361 0, sizeof(struct virtio_blk_req_hdr),
362 BUS_DMASYNC_PREWRITE);
363 bus_dmamap_sync(vsc->sc_dmat, vr->vr_payload,
364 0, bp->b_bcount,
365 isread?BUS_DMASYNC_PREREAD:BUS_DMASYNC_PREWRITE);
366 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
367 offsetof(struct virtio_blk_req, vr_status),
368 sizeof(uint8_t),
369 BUS_DMASYNC_PREREAD);
370
371 virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
372 0, sizeof(struct virtio_blk_req_hdr),
373 true);
374 virtio_enqueue(vsc, vq, slot, vr->vr_payload, !isread);
375 virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
376 offsetof(struct virtio_blk_req, vr_status),
377 sizeof(uint8_t),
378 false);
379 virtio_enqueue_commit(vsc, vq, slot, true);
380
381 return 0;
382 }
383
384 static void
385 ld_virtio_vq_done1(struct ld_virtio_softc *sc, struct virtio_softc *vsc,
386 struct virtqueue *vq, int slot)
387 {
388 struct virtio_blk_req *vr = &sc->sc_reqs[slot];
389 struct buf *bp = vr->vr_bp;
390
391 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
392 0, sizeof(struct virtio_blk_req_hdr),
393 BUS_DMASYNC_POSTWRITE);
394 bus_dmamap_sync(vsc->sc_dmat, vr->vr_payload,
395 0, bp->b_bcount,
396 (bp->b_flags & B_READ)?BUS_DMASYNC_POSTREAD
397 :BUS_DMASYNC_POSTWRITE);
398 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
399 sizeof(struct virtio_blk_req_hdr), sizeof(uint8_t),
400 BUS_DMASYNC_POSTREAD);
401
402 if (vr->vr_status != VIRTIO_BLK_S_OK) {
403 bp->b_error = EIO;
404 bp->b_resid = bp->b_bcount;
405 } else {
406 bp->b_error = 0;
407 bp->b_resid = 0;
408 }
409
410 virtio_dequeue_commit(vsc, vq, slot);
411
412 lddone(&sc->sc_ld, bp);
413 }
414
415 static int
416 ld_virtio_vq_done(struct virtqueue *vq)
417 {
418 struct virtio_softc *vsc = vq->vq_owner;
419 struct ld_virtio_softc *sc = device_private(vsc->sc_child);
420 int r = 0;
421 int slot;
422
423 again:
424 if (virtio_dequeue(vsc, vq, &slot, NULL))
425 return r;
426 r = 1;
427
428 ld_virtio_vq_done1(sc, vsc, vq, slot);
429 goto again;
430 }
431
432 static int
433 ld_virtio_dump(struct ld_softc *ld, void *data, int blkno, int blkcnt)
434 {
435 struct ld_virtio_softc *sc = device_private(ld->sc_dv);
436 struct virtio_softc *vsc = sc->sc_virtio;
437 struct virtqueue *vq = &sc->sc_vq[0];
438 struct virtio_blk_req *vr;
439 int slot, r;
440
441 if (sc->sc_readonly)
442 return EIO;
443
444 r = virtio_enqueue_prep(vsc, vq, &slot);
445 if (r != 0) {
446 if (r == EAGAIN) { /* no free slot; dequeue first */
447 delay(100);
448 ld_virtio_vq_done(vq);
449 r = virtio_enqueue_prep(vsc, vq, &slot);
450 if (r != 0)
451 return r;
452 }
453 return r;
454 }
455 vr = &sc->sc_reqs[slot];
456 r = bus_dmamap_load(vsc->sc_dmat, vr->vr_payload,
457 data, blkcnt*ld->sc_secsize, NULL,
458 BUS_DMA_WRITE|BUS_DMA_NOWAIT);
459 if (r != 0)
460 return r;
461
462 r = virtio_enqueue_reserve(vsc, vq, slot, vr->vr_payload->dm_nsegs + 2);
463 if (r != 0) {
464 bus_dmamap_unload(vsc->sc_dmat, vr->vr_payload);
465 return r;
466 }
467
468 vr->vr_bp = (void*)0xdeadbeef;
469 vr->vr_hdr.type = VIRTIO_BLK_T_OUT;
470 vr->vr_hdr.ioprio = 0;
471 vr->vr_hdr.sector = (daddr_t) blkno * ld->sc_secsize / 512;
472
473 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
474 0, sizeof(struct virtio_blk_req_hdr),
475 BUS_DMASYNC_PREWRITE);
476 bus_dmamap_sync(vsc->sc_dmat, vr->vr_payload,
477 0, blkcnt*ld->sc_secsize,
478 BUS_DMASYNC_PREWRITE);
479 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
480 offsetof(struct virtio_blk_req, vr_status),
481 sizeof(uint8_t),
482 BUS_DMASYNC_PREREAD);
483
484 virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
485 0, sizeof(struct virtio_blk_req_hdr),
486 true);
487 virtio_enqueue(vsc, vq, slot, vr->vr_payload, true);
488 virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
489 offsetof(struct virtio_blk_req, vr_status),
490 sizeof(uint8_t),
491 false);
492 virtio_enqueue_commit(vsc, vq, slot, true);
493
494 for ( ; ; ) {
495 int dslot;
496
497 r = virtio_dequeue(vsc, vq, &dslot, NULL);
498 if (r != 0)
499 continue;
500 if (dslot != slot) {
501 ld_virtio_vq_done1(sc, vsc, vq, dslot);
502 continue;
503 } else
504 break;
505 }
506
507 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
508 0, sizeof(struct virtio_blk_req_hdr),
509 BUS_DMASYNC_POSTWRITE);
510 bus_dmamap_sync(vsc->sc_dmat, vr->vr_payload,
511 0, blkcnt*ld->sc_secsize,
512 BUS_DMASYNC_POSTWRITE);
513 bus_dmamap_sync(vsc->sc_dmat, vr->vr_cmdsts,
514 offsetof(struct virtio_blk_req, vr_status),
515 sizeof(uint8_t),
516 BUS_DMASYNC_POSTREAD);
517 if (vr->vr_status == VIRTIO_BLK_S_OK)
518 r = 0;
519 else
520 r = EIO;
521 virtio_dequeue_commit(vsc, vq, slot);
522
523 return r;
524 }
525
526 static int
527 ld_virtio_detach(device_t self, int flags)
528 {
529 struct ld_virtio_softc *sc = device_private(self);
530 struct ld_softc *ld = &sc->sc_ld;
531 bus_dma_tag_t dmat = sc->sc_virtio->sc_dmat;
532 int r, i, qsize;
533
534 qsize = sc->sc_vq[0].vq_num;
535 r = ldbegindetach(ld, flags);
536 if (r != 0)
537 return r;
538 virtio_reset(sc->sc_virtio);
539 virtio_free_vq(sc->sc_virtio, &sc->sc_vq[0]);
540
541 for (i = 0; i < qsize; i++) {
542 bus_dmamap_destroy(dmat,
543 sc->sc_reqs[i].vr_cmdsts);
544 bus_dmamap_destroy(dmat,
545 sc->sc_reqs[i].vr_payload);
546 }
547 bus_dmamem_unmap(dmat, sc->sc_reqs,
548 sizeof(struct virtio_blk_req) * qsize);
549 bus_dmamem_free(dmat, &sc->sc_reqs_segs[0], 1);
550
551 ldenddetach(ld);
552
553 return 0;
554 }
555