1 /* 2 * XenBSD block device driver 3 * 4 * Copyright (c) 2010-2013 Spectra Logic Corporation 5 * Copyright (c) 2009 Scott Long, Yahoo! 6 * Copyright (c) 2009 Frank Suchomel, Citrix 7 * Copyright (c) 2009 Doug F. Rabson, Citrix 8 * Copyright (c) 2005 Kip Macy 9 * Copyright (c) 2003-2004, Keir Fraser & Steve Hand 10 * Modifications by Mark A. Williamson are (c) Intel Research Cambridge 11 * 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a copy 14 * of this software and associated documentation files (the "Software"), to 15 * deal in the Software without restriction, including without limitation the 16 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 17 * sell copies of the Software, and to permit persons to whom the Software is 18 * furnished to do so, subject to the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be included in 21 * all copies or substantial portions of the Software. 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 28 * DEALINGS IN THE SOFTWARE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/malloc.h> 37 #include <sys/kernel.h> 38 #include <vm/vm.h> 39 #include <vm/pmap.h> 40 41 #include <sys/bio.h> 42 #include <sys/bus.h> 43 #include <sys/conf.h> 44 #include <sys/module.h> 45 #include <sys/sysctl.h> 46 47 #include <machine/bus.h> 48 #include <sys/rman.h> 49 #include <machine/resource.h> 50 #include <machine/intr_machdep.h> 51 #include <machine/vmparam.h> 52 #include <sys/bus_dma.h> 53 54 #include <machine/_inttypes.h> 55 #include <machine/xen/xen-os.h> 56 #include <machine/xen/xenvar.h> 57 #include <machine/xen/xenfunc.h> 58 59 #include <xen/hypervisor.h> 60 #include <xen/xen_intr.h> 61 #include <xen/evtchn.h> 62 #include <xen/gnttab.h> 63 #include <xen/interface/grant_table.h> 64 #include <xen/interface/io/protocols.h> 65 #include <xen/xenbus/xenbusvar.h> 66 67 #include <geom/geom_disk.h> 68 69 #include <dev/xen/blkfront/block.h> 70 71 #include "xenbus_if.h" 72 73 /*--------------------------- Forward Declarations ---------------------------*/ 74 static void xbd_closing(device_t); 75 static void xbd_startio(struct xbd_softc *sc); 76 77 /*---------------------------------- Macros ----------------------------------*/ 78 #if 0 79 #define DPRINTK(fmt, args...) printf("[XEN] %s:%d: " fmt ".\n", __func__, __LINE__, ##args) 80 #else 81 #define DPRINTK(fmt, args...) 82 #endif 83 84 #define XBD_SECTOR_SHFT 9 85 86 #define XBD_STATE_DISCONNECTED 0 87 #define XBD_STATE_CONNECTED 1 88 #define XBD_STATE_SUSPENDED 2 89 90 /*---------------------------- Global Static Data ----------------------------*/ 91 static MALLOC_DEFINE(M_XENBLOCKFRONT, "xbd", "Xen Block Front driver data"); 92 93 /*---------------------------- Command Processing ----------------------------*/ 94 static inline void 95 xbd_flush_requests(struct xbd_softc *sc) 96 { 97 int notify; 98 99 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->xbd_ring, notify); 100 101 if (notify) 102 notify_remote_via_irq(sc->xbd_irq); 103 } 104 105 static void 106 xbd_free_command(struct xbd_command *cm) 107 { 108 109 KASSERT((cm->cm_flags & XBD_ON_XBDQ_MASK) == 0, 110 ("Freeing command that is still on a queue\n")); 111 112 cm->cm_flags = 0; 113 cm->cm_bp = NULL; 114 cm->cm_complete = NULL; 115 xbd_enqueue_free(cm); 116 } 117 118 static void 119 xbd_queue_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error) 120 { 121 struct xbd_softc *sc; 122 struct xbd_command *cm; 123 blkif_request_t *ring_req; 124 struct blkif_request_segment *sg; 125 struct blkif_request_segment *last_block_sg; 126 grant_ref_t *sg_ref; 127 vm_paddr_t buffer_ma; 128 uint64_t fsect, lsect; 129 int ref; 130 int op; 131 int block_segs; 132 133 cm = arg; 134 sc = cm->cm_sc; 135 136 if (error) { 137 printf("error %d in xbd_queue_cb\n", error); 138 cm->cm_bp->bio_error = EIO; 139 biodone(cm->cm_bp); 140 xbd_free_command(cm); 141 return; 142 } 143 144 /* Fill out a communications ring structure. */ 145 ring_req = RING_GET_REQUEST(&sc->xbd_ring, sc->xbd_ring.req_prod_pvt); 146 sc->xbd_ring.req_prod_pvt++; 147 ring_req->id = cm->cm_id; 148 ring_req->operation = cm->cm_operation; 149 ring_req->sector_number = cm->cm_sector_number; 150 ring_req->handle = (blkif_vdev_t)(uintptr_t)sc->xbd_disk; 151 ring_req->nr_segments = nsegs; 152 cm->cm_nseg = nsegs; 153 154 block_segs = MIN(nsegs, BLKIF_MAX_SEGMENTS_PER_HEADER_BLOCK); 155 sg = ring_req->seg; 156 last_block_sg = sg + block_segs; 157 sg_ref = cm->cm_sg_refs; 158 159 while (1) { 160 161 while (sg < last_block_sg) { 162 buffer_ma = segs->ds_addr; 163 fsect = (buffer_ma & PAGE_MASK) >> XBD_SECTOR_SHFT; 164 lsect = fsect + (segs->ds_len >> XBD_SECTOR_SHFT) - 1; 165 166 KASSERT(lsect <= 7, ("XEN disk driver data cannot " 167 "cross a page boundary")); 168 169 /* install a grant reference. */ 170 ref = gnttab_claim_grant_reference(&cm->cm_gref_head); 171 172 /* 173 * GNTTAB_LIST_END == 0xffffffff, but it is private 174 * to gnttab.c. 175 */ 176 KASSERT(ref != ~0, ("grant_reference failed")); 177 178 gnttab_grant_foreign_access_ref( 179 ref, 180 xenbus_get_otherend_id(sc->xbd_dev), 181 buffer_ma >> PAGE_SHIFT, 182 ring_req->operation == BLKIF_OP_WRITE); 183 184 *sg_ref = ref; 185 *sg = (struct blkif_request_segment) { 186 .gref = ref, 187 .first_sect = fsect, 188 .last_sect = lsect 189 }; 190 sg++; 191 sg_ref++; 192 segs++; 193 nsegs--; 194 } 195 block_segs = MIN(nsegs, BLKIF_MAX_SEGMENTS_PER_SEGMENT_BLOCK); 196 if (block_segs == 0) 197 break; 198 199 sg = BLKRING_GET_SEG_BLOCK(&sc->xbd_ring, 200 sc->xbd_ring.req_prod_pvt); 201 sc->xbd_ring.req_prod_pvt++; 202 last_block_sg = sg + block_segs; 203 } 204 205 if (cm->cm_operation == BLKIF_OP_READ) 206 op = BUS_DMASYNC_PREREAD; 207 else if (cm->cm_operation == BLKIF_OP_WRITE) 208 op = BUS_DMASYNC_PREWRITE; 209 else 210 op = 0; 211 bus_dmamap_sync(sc->xbd_io_dmat, cm->cm_map, op); 212 213 gnttab_free_grant_references(cm->cm_gref_head); 214 215 xbd_enqueue_busy(cm); 216 217 /* 218 * This flag means that we're probably executing in the busdma swi 219 * instead of in the startio context, so an explicit flush is needed. 220 */ 221 if (cm->cm_flags & XBD_CMD_FROZEN) 222 xbd_flush_requests(sc); 223 224 return; 225 } 226 227 static int 228 xbd_queue_request(struct xbd_softc *sc, struct xbd_command *cm) 229 { 230 int error; 231 232 error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map, cm->cm_data, 233 cm->cm_datalen, xbd_queue_cb, cm, 0); 234 if (error == EINPROGRESS) { 235 printf("EINPROGRESS\n"); 236 sc->xbd_flags |= XBD_FROZEN; 237 cm->cm_flags |= XBD_CMD_FROZEN; 238 return (0); 239 } 240 241 return (error); 242 } 243 244 static void 245 xbd_restart_queue_callback(void *arg) 246 { 247 struct xbd_softc *sc = arg; 248 249 mtx_lock(&sc->xbd_io_lock); 250 251 xbd_startio(sc); 252 253 mtx_unlock(&sc->xbd_io_lock); 254 } 255 256 static struct xbd_command * 257 xbd_bio_command(struct xbd_softc *sc) 258 { 259 struct xbd_command *cm; 260 struct bio *bp; 261 262 if (unlikely(sc->xbd_connected != XBD_STATE_CONNECTED)) 263 return (NULL); 264 265 bp = xbd_dequeue_bio(sc); 266 if (bp == NULL) 267 return (NULL); 268 269 if ((cm = xbd_dequeue_free(sc)) == NULL) { 270 xbd_requeue_bio(sc, bp); 271 return (NULL); 272 } 273 274 if (gnttab_alloc_grant_references(sc->xbd_max_request_segments, 275 &cm->cm_gref_head) != 0) { 276 gnttab_request_free_callback(&sc->xbd_callback, 277 xbd_restart_queue_callback, sc, 278 sc->xbd_max_request_segments); 279 xbd_requeue_bio(sc, bp); 280 xbd_enqueue_free(cm); 281 sc->xbd_flags |= XBD_FROZEN; 282 return (NULL); 283 } 284 285 cm->cm_bp = bp; 286 cm->cm_data = bp->bio_data; 287 cm->cm_datalen = bp->bio_bcount; 288 cm->cm_operation = (bp->bio_cmd == BIO_READ) ? 289 BLKIF_OP_READ : BLKIF_OP_WRITE; 290 cm->cm_sector_number = (blkif_sector_t)bp->bio_pblkno; 291 292 return (cm); 293 } 294 295 /* 296 * Dequeue buffers and place them in the shared communication ring. 297 * Return when no more requests can be accepted or all buffers have 298 * been queued. 299 * 300 * Signal XEN once the ring has been filled out. 301 */ 302 static void 303 xbd_startio(struct xbd_softc *sc) 304 { 305 struct xbd_command *cm; 306 int error, queued = 0; 307 308 mtx_assert(&sc->xbd_io_lock, MA_OWNED); 309 310 if (sc->xbd_connected != XBD_STATE_CONNECTED) 311 return; 312 313 while (RING_FREE_REQUESTS(&sc->xbd_ring) >= 314 sc->xbd_max_request_blocks) { 315 if (sc->xbd_flags & XBD_FROZEN) 316 break; 317 318 cm = xbd_dequeue_ready(sc); 319 320 if (cm == NULL) 321 cm = xbd_bio_command(sc); 322 323 if (cm == NULL) 324 break; 325 326 if ((error = xbd_queue_request(sc, cm)) != 0) { 327 printf("xbd_queue_request returned %d\n", error); 328 break; 329 } 330 queued++; 331 } 332 333 if (queued != 0) 334 xbd_flush_requests(sc); 335 } 336 337 static void 338 xbd_bio_complete(struct xbd_softc *sc, struct xbd_command *cm) 339 { 340 struct bio *bp; 341 342 bp = cm->cm_bp; 343 344 if (unlikely(cm->cm_status != BLKIF_RSP_OKAY)) { 345 disk_err(bp, "disk error" , -1, 0); 346 printf(" status: %x\n", cm->cm_status); 347 bp->bio_flags |= BIO_ERROR; 348 } 349 350 if (bp->bio_flags & BIO_ERROR) 351 bp->bio_error = EIO; 352 else 353 bp->bio_resid = 0; 354 355 xbd_free_command(cm); 356 biodone(bp); 357 } 358 359 static int 360 xbd_completion(struct xbd_command *cm) 361 { 362 gnttab_end_foreign_access_references(cm->cm_nseg, cm->cm_sg_refs); 363 return (BLKIF_SEGS_TO_BLOCKS(cm->cm_nseg)); 364 } 365 366 static void 367 xbd_int(void *xsc) 368 { 369 struct xbd_softc *sc = xsc; 370 struct xbd_command *cm; 371 blkif_response_t *bret; 372 RING_IDX i, rp; 373 int op; 374 375 mtx_lock(&sc->xbd_io_lock); 376 377 if (unlikely(sc->xbd_connected == XBD_STATE_DISCONNECTED)) { 378 mtx_unlock(&sc->xbd_io_lock); 379 return; 380 } 381 382 again: 383 rp = sc->xbd_ring.sring->rsp_prod; 384 rmb(); /* Ensure we see queued responses up to 'rp'. */ 385 386 for (i = sc->xbd_ring.rsp_cons; i != rp;) { 387 bret = RING_GET_RESPONSE(&sc->xbd_ring, i); 388 cm = &sc->xbd_shadow[bret->id]; 389 390 xbd_remove_busy(cm); 391 i += xbd_completion(cm); 392 393 if (cm->cm_operation == BLKIF_OP_READ) 394 op = BUS_DMASYNC_POSTREAD; 395 else if (cm->cm_operation == BLKIF_OP_WRITE) 396 op = BUS_DMASYNC_POSTWRITE; 397 else 398 op = 0; 399 bus_dmamap_sync(sc->xbd_io_dmat, cm->cm_map, op); 400 bus_dmamap_unload(sc->xbd_io_dmat, cm->cm_map); 401 402 /* 403 * If commands are completing then resources are probably 404 * being freed as well. It's a cheap assumption even when 405 * wrong. 406 */ 407 sc->xbd_flags &= ~XBD_FROZEN; 408 409 /* 410 * Directly call the i/o complete routine to save an 411 * an indirection in the common case. 412 */ 413 cm->cm_status = bret->status; 414 if (cm->cm_bp) 415 xbd_bio_complete(sc, cm); 416 else if (cm->cm_complete != NULL) 417 cm->cm_complete(cm); 418 else 419 xbd_free_command(cm); 420 } 421 422 sc->xbd_ring.rsp_cons = i; 423 424 if (i != sc->xbd_ring.req_prod_pvt) { 425 int more_to_do; 426 RING_FINAL_CHECK_FOR_RESPONSES(&sc->xbd_ring, more_to_do); 427 if (more_to_do) 428 goto again; 429 } else { 430 sc->xbd_ring.sring->rsp_event = i + 1; 431 } 432 433 xbd_startio(sc); 434 435 if (unlikely(sc->xbd_connected == XBD_STATE_SUSPENDED)) 436 wakeup(&sc->xbd_cm_busy); 437 438 mtx_unlock(&sc->xbd_io_lock); 439 } 440 441 /*------------------------------- Dump Support -------------------------------*/ 442 /** 443 * Quiesce the disk writes for a dump file before allowing the next buffer. 444 */ 445 static void 446 xbd_quiesce(struct xbd_softc *sc) 447 { 448 int mtd; 449 450 // While there are outstanding requests 451 while (!TAILQ_EMPTY(&sc->xbd_cm_busy)) { 452 RING_FINAL_CHECK_FOR_RESPONSES(&sc->xbd_ring, mtd); 453 if (mtd) { 454 /* Recieved request completions, update queue. */ 455 xbd_int(sc); 456 } 457 if (!TAILQ_EMPTY(&sc->xbd_cm_busy)) { 458 /* 459 * Still pending requests, wait for the disk i/o 460 * to complete. 461 */ 462 HYPERVISOR_yield(); 463 } 464 } 465 } 466 467 /* Kernel dump function for a paravirtualized disk device */ 468 static void 469 xbd_dump_complete(struct xbd_command *cm) 470 { 471 472 xbd_enqueue_complete(cm); 473 } 474 475 static int 476 xbd_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 477 size_t length) 478 { 479 struct disk *dp = arg; 480 struct xbd_softc *sc = dp->d_drv1; 481 struct xbd_command *cm; 482 size_t chunk; 483 int sbp; 484 int rc = 0; 485 486 if (length <= 0) 487 return (rc); 488 489 xbd_quiesce(sc); /* All quiet on the western front. */ 490 491 /* 492 * If this lock is held, then this module is failing, and a 493 * successful kernel dump is highly unlikely anyway. 494 */ 495 mtx_lock(&sc->xbd_io_lock); 496 497 /* Split the 64KB block as needed */ 498 for (sbp=0; length > 0; sbp++) { 499 cm = xbd_dequeue_free(sc); 500 if (cm == NULL) { 501 mtx_unlock(&sc->xbd_io_lock); 502 device_printf(sc->xbd_dev, "dump: no more commands?\n"); 503 return (EBUSY); 504 } 505 506 if (gnttab_alloc_grant_references(sc->xbd_max_request_segments, 507 &cm->cm_gref_head) != 0) { 508 xbd_free_command(cm); 509 mtx_unlock(&sc->xbd_io_lock); 510 device_printf(sc->xbd_dev, "no more grant allocs?\n"); 511 return (EBUSY); 512 } 513 514 chunk = length > sc->xbd_max_request_size ? 515 sc->xbd_max_request_size : length; 516 cm->cm_data = virtual; 517 cm->cm_datalen = chunk; 518 cm->cm_operation = BLKIF_OP_WRITE; 519 cm->cm_sector_number = offset / dp->d_sectorsize; 520 cm->cm_complete = xbd_dump_complete; 521 522 xbd_enqueue_ready(cm); 523 524 length -= chunk; 525 offset += chunk; 526 virtual = (char *) virtual + chunk; 527 } 528 529 /* Tell DOM0 to do the I/O */ 530 xbd_startio(sc); 531 mtx_unlock(&sc->xbd_io_lock); 532 533 /* Poll for the completion. */ 534 xbd_quiesce(sc); /* All quite on the eastern front */ 535 536 /* If there were any errors, bail out... */ 537 while ((cm = xbd_dequeue_complete(sc)) != NULL) { 538 if (cm->cm_status != BLKIF_RSP_OKAY) { 539 device_printf(sc->xbd_dev, 540 "Dump I/O failed at sector %jd\n", 541 cm->cm_sector_number); 542 rc = EIO; 543 } 544 xbd_free_command(cm); 545 } 546 547 return (rc); 548 } 549 550 /*----------------------------- Disk Entrypoints -----------------------------*/ 551 static int 552 xbd_open(struct disk *dp) 553 { 554 struct xbd_softc *sc = dp->d_drv1; 555 556 if (sc == NULL) { 557 printf("xb%d: not found", sc->xbd_unit); 558 return (ENXIO); 559 } 560 561 sc->xbd_flags |= XBD_OPEN; 562 sc->xbd_users++; 563 return (0); 564 } 565 566 static int 567 xbd_close(struct disk *dp) 568 { 569 struct xbd_softc *sc = dp->d_drv1; 570 571 if (sc == NULL) 572 return (ENXIO); 573 sc->xbd_flags &= ~XBD_OPEN; 574 if (--(sc->xbd_users) == 0) { 575 /* 576 * Check whether we have been instructed to close. We will 577 * have ignored this request initially, as the device was 578 * still mounted. 579 */ 580 if (xenbus_get_otherend_state(sc->xbd_dev) == 581 XenbusStateClosing) 582 xbd_closing(sc->xbd_dev); 583 } 584 return (0); 585 } 586 587 static int 588 xbd_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, struct thread *td) 589 { 590 struct xbd_softc *sc = dp->d_drv1; 591 592 if (sc == NULL) 593 return (ENXIO); 594 595 return (ENOTTY); 596 } 597 598 /* 599 * Read/write routine for a buffer. Finds the proper unit, place it on 600 * the sortq and kick the controller. 601 */ 602 static void 603 xbd_strategy(struct bio *bp) 604 { 605 struct xbd_softc *sc = bp->bio_disk->d_drv1; 606 607 /* bogus disk? */ 608 if (sc == NULL) { 609 bp->bio_error = EINVAL; 610 bp->bio_flags |= BIO_ERROR; 611 bp->bio_resid = bp->bio_bcount; 612 biodone(bp); 613 return; 614 } 615 616 /* 617 * Place it in the queue of disk activities for this disk 618 */ 619 mtx_lock(&sc->xbd_io_lock); 620 621 xbd_enqueue_bio(sc, bp); 622 xbd_startio(sc); 623 624 mtx_unlock(&sc->xbd_io_lock); 625 return; 626 } 627 628 /*------------------------------ Ring Management -----------------------------*/ 629 static int 630 xbd_alloc_ring(struct xbd_softc *sc) 631 { 632 blkif_sring_t *sring; 633 uintptr_t sring_page_addr; 634 int error; 635 int i; 636 637 sring = malloc(sc->xbd_ring_pages * PAGE_SIZE, M_XENBLOCKFRONT, 638 M_NOWAIT|M_ZERO); 639 if (sring == NULL) { 640 xenbus_dev_fatal(sc->xbd_dev, ENOMEM, "allocating shared ring"); 641 return (ENOMEM); 642 } 643 SHARED_RING_INIT(sring); 644 FRONT_RING_INIT(&sc->xbd_ring, sring, sc->xbd_ring_pages * PAGE_SIZE); 645 646 for (i = 0, sring_page_addr = (uintptr_t)sring; 647 i < sc->xbd_ring_pages; 648 i++, sring_page_addr += PAGE_SIZE) { 649 650 error = xenbus_grant_ring(sc->xbd_dev, 651 (vtomach(sring_page_addr) >> PAGE_SHIFT), 652 &sc->xbd_ring_ref[i]); 653 if (error) { 654 xenbus_dev_fatal(sc->xbd_dev, error, 655 "granting ring_ref(%d)", i); 656 return (error); 657 } 658 } 659 if (sc->xbd_ring_pages == 1) { 660 error = xs_printf(XST_NIL, xenbus_get_node(sc->xbd_dev), 661 "ring-ref", "%u", sc->xbd_ring_ref[0]); 662 if (error) { 663 xenbus_dev_fatal(sc->xbd_dev, error, 664 "writing %s/ring-ref", 665 xenbus_get_node(sc->xbd_dev)); 666 return (error); 667 } 668 } else { 669 for (i = 0; i < sc->xbd_ring_pages; i++) { 670 char ring_ref_name[]= "ring_refXX"; 671 672 snprintf(ring_ref_name, sizeof(ring_ref_name), 673 "ring-ref%u", i); 674 error = xs_printf(XST_NIL, xenbus_get_node(sc->xbd_dev), 675 ring_ref_name, "%u", sc->xbd_ring_ref[i]); 676 if (error) { 677 xenbus_dev_fatal(sc->xbd_dev, error, 678 "writing %s/%s", 679 xenbus_get_node(sc->xbd_dev), 680 ring_ref_name); 681 return (error); 682 } 683 } 684 } 685 686 error = bind_listening_port_to_irqhandler( 687 xenbus_get_otherend_id(sc->xbd_dev), 688 "xbd", (driver_intr_t *)xbd_int, sc, 689 INTR_TYPE_BIO | INTR_MPSAFE, &sc->xbd_irq); 690 if (error) { 691 xenbus_dev_fatal(sc->xbd_dev, error, 692 "bind_evtchn_to_irqhandler failed"); 693 return (error); 694 } 695 696 return (0); 697 } 698 699 static void 700 xbd_free_ring(struct xbd_softc *sc) 701 { 702 int i; 703 704 if (sc->xbd_ring.sring == NULL) 705 return; 706 707 for (i = 0; i < sc->xbd_ring_pages; i++) { 708 if (sc->xbd_ring_ref[i] != GRANT_REF_INVALID) { 709 gnttab_end_foreign_access_ref(sc->xbd_ring_ref[i]); 710 sc->xbd_ring_ref[i] = GRANT_REF_INVALID; 711 } 712 } 713 free(sc->xbd_ring.sring, M_XENBLOCKFRONT); 714 sc->xbd_ring.sring = NULL; 715 } 716 717 /*-------------------------- Initialization/Teardown -------------------------*/ 718 static void 719 xbd_setup_sysctl(struct xbd_softc *xbd) 720 { 721 struct sysctl_ctx_list *sysctl_ctx = NULL; 722 struct sysctl_oid *sysctl_tree = NULL; 723 724 sysctl_ctx = device_get_sysctl_ctx(xbd->xbd_dev); 725 if (sysctl_ctx == NULL) 726 return; 727 728 sysctl_tree = device_get_sysctl_tree(xbd->xbd_dev); 729 if (sysctl_tree == NULL) 730 return; 731 732 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 733 "max_requests", CTLFLAG_RD, &xbd->xbd_max_requests, -1, 734 "maximum outstanding requests (negotiated)"); 735 736 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 737 "max_request_segments", CTLFLAG_RD, 738 &xbd->xbd_max_request_segments, 0, 739 "maximum number of pages per requests (negotiated)"); 740 741 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 742 "max_request_size", CTLFLAG_RD, &xbd->xbd_max_request_size, 0, 743 "maximum size in bytes of a request (negotiated)"); 744 745 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 746 "ring_pages", CTLFLAG_RD, &xbd->xbd_ring_pages, 0, 747 "communication channel pages (negotiated)"); 748 } 749 750 /* 751 * Translate Linux major/minor to an appropriate name and unit 752 * number. For HVM guests, this allows us to use the same drive names 753 * with blkfront as the emulated drives, easing transition slightly. 754 */ 755 static void 756 xbd_vdevice_to_unit(uint32_t vdevice, int *unit, const char **name) 757 { 758 static struct vdev_info { 759 int major; 760 int shift; 761 int base; 762 const char *name; 763 } info[] = { 764 {3, 6, 0, "ada"}, /* ide0 */ 765 {22, 6, 2, "ada"}, /* ide1 */ 766 {33, 6, 4, "ada"}, /* ide2 */ 767 {34, 6, 6, "ada"}, /* ide3 */ 768 {56, 6, 8, "ada"}, /* ide4 */ 769 {57, 6, 10, "ada"}, /* ide5 */ 770 {88, 6, 12, "ada"}, /* ide6 */ 771 {89, 6, 14, "ada"}, /* ide7 */ 772 {90, 6, 16, "ada"}, /* ide8 */ 773 {91, 6, 18, "ada"}, /* ide9 */ 774 775 {8, 4, 0, "da"}, /* scsi disk0 */ 776 {65, 4, 16, "da"}, /* scsi disk1 */ 777 {66, 4, 32, "da"}, /* scsi disk2 */ 778 {67, 4, 48, "da"}, /* scsi disk3 */ 779 {68, 4, 64, "da"}, /* scsi disk4 */ 780 {69, 4, 80, "da"}, /* scsi disk5 */ 781 {70, 4, 96, "da"}, /* scsi disk6 */ 782 {71, 4, 112, "da"}, /* scsi disk7 */ 783 {128, 4, 128, "da"}, /* scsi disk8 */ 784 {129, 4, 144, "da"}, /* scsi disk9 */ 785 {130, 4, 160, "da"}, /* scsi disk10 */ 786 {131, 4, 176, "da"}, /* scsi disk11 */ 787 {132, 4, 192, "da"}, /* scsi disk12 */ 788 {133, 4, 208, "da"}, /* scsi disk13 */ 789 {134, 4, 224, "da"}, /* scsi disk14 */ 790 {135, 4, 240, "da"}, /* scsi disk15 */ 791 792 {202, 4, 0, "xbd"}, /* xbd */ 793 794 {0, 0, 0, NULL}, 795 }; 796 int major = vdevice >> 8; 797 int minor = vdevice & 0xff; 798 int i; 799 800 if (vdevice & (1 << 28)) { 801 *unit = (vdevice & ((1 << 28) - 1)) >> 8; 802 *name = "xbd"; 803 return; 804 } 805 806 for (i = 0; info[i].major; i++) { 807 if (info[i].major == major) { 808 *unit = info[i].base + (minor >> info[i].shift); 809 *name = info[i].name; 810 return; 811 } 812 } 813 814 *unit = minor >> 4; 815 *name = "xbd"; 816 } 817 818 int 819 xbd_instance_create(struct xbd_softc *sc, blkif_sector_t sectors, 820 int vdevice, uint16_t vdisk_info, unsigned long sector_size) 821 { 822 int unit, error = 0; 823 const char *name; 824 825 xbd_vdevice_to_unit(vdevice, &unit, &name); 826 827 sc->xbd_unit = unit; 828 829 if (strcmp(name, "xbd")) 830 device_printf(sc->xbd_dev, "attaching as %s%d\n", name, unit); 831 832 sc->xbd_disk = disk_alloc(); 833 sc->xbd_disk->d_unit = sc->xbd_unit; 834 sc->xbd_disk->d_open = xbd_open; 835 sc->xbd_disk->d_close = xbd_close; 836 sc->xbd_disk->d_ioctl = xbd_ioctl; 837 sc->xbd_disk->d_strategy = xbd_strategy; 838 sc->xbd_disk->d_dump = xbd_dump; 839 sc->xbd_disk->d_name = name; 840 sc->xbd_disk->d_drv1 = sc; 841 sc->xbd_disk->d_sectorsize = sector_size; 842 843 sc->xbd_disk->d_mediasize = sectors * sector_size; 844 sc->xbd_disk->d_maxsize = sc->xbd_max_request_size; 845 sc->xbd_disk->d_flags = 0; 846 disk_create(sc->xbd_disk, DISK_VERSION); 847 848 return error; 849 } 850 851 static void 852 xbd_free(struct xbd_softc *sc) 853 { 854 int i; 855 856 /* Prevent new requests being issued until we fix things up. */ 857 mtx_lock(&sc->xbd_io_lock); 858 sc->xbd_connected = XBD_STATE_DISCONNECTED; 859 mtx_unlock(&sc->xbd_io_lock); 860 861 /* Free resources associated with old device channel. */ 862 xbd_free_ring(sc); 863 if (sc->xbd_shadow) { 864 865 for (i = 0; i < sc->xbd_max_requests; i++) { 866 struct xbd_command *cm; 867 868 cm = &sc->xbd_shadow[i]; 869 if (cm->cm_sg_refs != NULL) { 870 free(cm->cm_sg_refs, M_XENBLOCKFRONT); 871 cm->cm_sg_refs = NULL; 872 } 873 874 bus_dmamap_destroy(sc->xbd_io_dmat, cm->cm_map); 875 } 876 free(sc->xbd_shadow, M_XENBLOCKFRONT); 877 sc->xbd_shadow = NULL; 878 879 bus_dma_tag_destroy(sc->xbd_io_dmat); 880 881 xbd_initq_free(sc); 882 xbd_initq_ready(sc); 883 xbd_initq_complete(sc); 884 } 885 886 if (sc->xbd_irq) { 887 unbind_from_irqhandler(sc->xbd_irq); 888 sc->xbd_irq = 0; 889 } 890 } 891 892 /*--------------------------- State Change Handlers --------------------------*/ 893 static void 894 xbd_initialize(struct xbd_softc *sc) 895 { 896 const char *otherend_path; 897 const char *node_path; 898 uint32_t max_ring_page_order; 899 int error; 900 int i; 901 902 if (xenbus_get_state(sc->xbd_dev) != XenbusStateInitialising) { 903 /* Initialization has already been performed. */ 904 return; 905 } 906 907 /* 908 * Protocol defaults valid even if negotiation for a 909 * setting fails. 910 */ 911 max_ring_page_order = 0; 912 sc->xbd_ring_pages = 1; 913 sc->xbd_max_request_segments = BLKIF_MAX_SEGMENTS_PER_HEADER_BLOCK; 914 sc->xbd_max_request_size = 915 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments); 916 sc->xbd_max_request_blocks = 917 BLKIF_SEGS_TO_BLOCKS(sc->xbd_max_request_segments); 918 919 /* 920 * Protocol negotiation. 921 * 922 * \note xs_gather() returns on the first encountered error, so 923 * we must use independant calls in order to guarantee 924 * we don't miss information in a sparsly populated back-end 925 * tree. 926 * 927 * \note xs_scanf() does not update variables for unmatched 928 * fields. 929 */ 930 otherend_path = xenbus_get_otherend_path(sc->xbd_dev); 931 node_path = xenbus_get_node(sc->xbd_dev); 932 933 /* Support both backend schemes for relaying ring page limits. */ 934 (void)xs_scanf(XST_NIL, otherend_path, 935 "max-ring-page-order", NULL, "%" PRIu32, 936 &max_ring_page_order); 937 sc->xbd_ring_pages = 1 << max_ring_page_order; 938 (void)xs_scanf(XST_NIL, otherend_path, 939 "max-ring-pages", NULL, "%" PRIu32, 940 &sc->xbd_ring_pages); 941 if (sc->xbd_ring_pages < 1) 942 sc->xbd_ring_pages = 1; 943 944 sc->xbd_max_requests = 945 BLKIF_MAX_RING_REQUESTS(sc->xbd_ring_pages * PAGE_SIZE); 946 (void)xs_scanf(XST_NIL, otherend_path, 947 "max-requests", NULL, "%" PRIu32, 948 &sc->xbd_max_requests); 949 950 (void)xs_scanf(XST_NIL, otherend_path, 951 "max-request-segments", NULL, "%" PRIu32, 952 &sc->xbd_max_request_segments); 953 954 (void)xs_scanf(XST_NIL, otherend_path, 955 "max-request-size", NULL, "%" PRIu32, 956 &sc->xbd_max_request_size); 957 958 if (sc->xbd_ring_pages > XBD_MAX_RING_PAGES) { 959 device_printf(sc->xbd_dev, 960 "Back-end specified ring-pages of %u " 961 "limited to front-end limit of %zu.\n", 962 sc->xbd_ring_pages, XBD_MAX_RING_PAGES); 963 sc->xbd_ring_pages = XBD_MAX_RING_PAGES; 964 } 965 966 if (powerof2(sc->xbd_ring_pages) == 0) { 967 uint32_t new_page_limit; 968 969 new_page_limit = 0x01 << (fls(sc->xbd_ring_pages) - 1); 970 device_printf(sc->xbd_dev, 971 "Back-end specified ring-pages of %u " 972 "is not a power of 2. Limited to %u.\n", 973 sc->xbd_ring_pages, new_page_limit); 974 sc->xbd_ring_pages = new_page_limit; 975 } 976 977 if (sc->xbd_max_requests > XBD_MAX_REQUESTS) { 978 device_printf(sc->xbd_dev, 979 "Back-end specified max_requests of %u " 980 "limited to front-end limit of %u.\n", 981 sc->xbd_max_requests, XBD_MAX_REQUESTS); 982 sc->xbd_max_requests = XBD_MAX_REQUESTS; 983 } 984 985 if (sc->xbd_max_request_segments > XBD_MAX_SEGMENTS_PER_REQUEST) { 986 device_printf(sc->xbd_dev, 987 "Back-end specified max_request_segments of %u " 988 "limited to front-end limit of %u.\n", 989 sc->xbd_max_request_segments, 990 XBD_MAX_SEGMENTS_PER_REQUEST); 991 sc->xbd_max_request_segments = XBD_MAX_SEGMENTS_PER_REQUEST; 992 } 993 994 if (sc->xbd_max_request_size > XBD_MAX_REQUEST_SIZE) { 995 device_printf(sc->xbd_dev, 996 "Back-end specified max_request_size of %u " 997 "limited to front-end limit of %u.\n", 998 sc->xbd_max_request_size, 999 XBD_MAX_REQUEST_SIZE); 1000 sc->xbd_max_request_size = XBD_MAX_REQUEST_SIZE; 1001 } 1002 1003 if (sc->xbd_max_request_size > 1004 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments)) { 1005 device_printf(sc->xbd_dev, 1006 "Back-end specified max_request_size of %u " 1007 "limited to front-end limit of %u. (Too few segments.)\n", 1008 sc->xbd_max_request_size, 1009 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments)); 1010 sc->xbd_max_request_size = 1011 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments); 1012 } 1013 1014 sc->xbd_max_request_blocks = 1015 BLKIF_SEGS_TO_BLOCKS(sc->xbd_max_request_segments); 1016 1017 /* Allocate datastructures based on negotiated values. */ 1018 error = bus_dma_tag_create( 1019 bus_get_dma_tag(sc->xbd_dev), /* parent */ 1020 512, PAGE_SIZE, /* algnmnt, boundary */ 1021 BUS_SPACE_MAXADDR, /* lowaddr */ 1022 BUS_SPACE_MAXADDR, /* highaddr */ 1023 NULL, NULL, /* filter, filterarg */ 1024 sc->xbd_max_request_size, 1025 sc->xbd_max_request_segments, 1026 PAGE_SIZE, /* maxsegsize */ 1027 BUS_DMA_ALLOCNOW, /* flags */ 1028 busdma_lock_mutex, /* lockfunc */ 1029 &sc->xbd_io_lock, /* lockarg */ 1030 &sc->xbd_io_dmat); 1031 if (error != 0) { 1032 xenbus_dev_fatal(sc->xbd_dev, error, 1033 "Cannot allocate parent DMA tag\n"); 1034 return; 1035 } 1036 1037 /* Per-transaction data allocation. */ 1038 sc->xbd_shadow = malloc(sizeof(*sc->xbd_shadow) * sc->xbd_max_requests, 1039 M_XENBLOCKFRONT, M_NOWAIT|M_ZERO); 1040 if (sc->xbd_shadow == NULL) { 1041 bus_dma_tag_destroy(sc->xbd_io_dmat); 1042 xenbus_dev_fatal(sc->xbd_dev, error, 1043 "Cannot allocate request structures\n"); 1044 return; 1045 } 1046 1047 for (i = 0; i < sc->xbd_max_requests; i++) { 1048 struct xbd_command *cm; 1049 1050 cm = &sc->xbd_shadow[i]; 1051 cm->cm_sg_refs = malloc( 1052 sizeof(grant_ref_t) * sc->xbd_max_request_segments, 1053 M_XENBLOCKFRONT, M_NOWAIT); 1054 if (cm->cm_sg_refs == NULL) 1055 break; 1056 cm->cm_id = i; 1057 cm->cm_sc = sc; 1058 if (bus_dmamap_create(sc->xbd_io_dmat, 0, &cm->cm_map) != 0) 1059 break; 1060 xbd_free_command(cm); 1061 } 1062 1063 if (xbd_alloc_ring(sc) != 0) 1064 return; 1065 1066 /* Support both backend schemes for relaying ring page limits. */ 1067 if (sc->xbd_ring_pages > 1) { 1068 error = xs_printf(XST_NIL, node_path, 1069 "num-ring-pages","%u", 1070 sc->xbd_ring_pages); 1071 if (error) { 1072 xenbus_dev_fatal(sc->xbd_dev, error, 1073 "writing %s/num-ring-pages", 1074 node_path); 1075 return; 1076 } 1077 1078 error = xs_printf(XST_NIL, node_path, 1079 "ring-page-order", "%u", 1080 fls(sc->xbd_ring_pages) - 1); 1081 if (error) { 1082 xenbus_dev_fatal(sc->xbd_dev, error, 1083 "writing %s/ring-page-order", 1084 node_path); 1085 return; 1086 } 1087 } 1088 1089 error = xs_printf(XST_NIL, node_path, 1090 "max-requests","%u", 1091 sc->xbd_max_requests); 1092 if (error) { 1093 xenbus_dev_fatal(sc->xbd_dev, error, 1094 "writing %s/max-requests", 1095 node_path); 1096 return; 1097 } 1098 1099 error = xs_printf(XST_NIL, node_path, 1100 "max-request-segments","%u", 1101 sc->xbd_max_request_segments); 1102 if (error) { 1103 xenbus_dev_fatal(sc->xbd_dev, error, 1104 "writing %s/max-request-segments", 1105 node_path); 1106 return; 1107 } 1108 1109 error = xs_printf(XST_NIL, node_path, 1110 "max-request-size","%u", 1111 sc->xbd_max_request_size); 1112 if (error) { 1113 xenbus_dev_fatal(sc->xbd_dev, error, 1114 "writing %s/max-request-size", 1115 node_path); 1116 return; 1117 } 1118 1119 error = xs_printf(XST_NIL, node_path, "event-channel", 1120 "%u", irq_to_evtchn_port(sc->xbd_irq)); 1121 if (error) { 1122 xenbus_dev_fatal(sc->xbd_dev, error, 1123 "writing %s/event-channel", 1124 node_path); 1125 return; 1126 } 1127 1128 error = xs_printf(XST_NIL, node_path, "protocol", 1129 "%s", XEN_IO_PROTO_ABI_NATIVE); 1130 if (error) { 1131 xenbus_dev_fatal(sc->xbd_dev, error, 1132 "writing %s/protocol", 1133 node_path); 1134 return; 1135 } 1136 1137 xenbus_set_state(sc->xbd_dev, XenbusStateInitialised); 1138 } 1139 1140 /* 1141 * Invoked when the backend is finally 'ready' (and has published 1142 * the details about the physical device - #sectors, size, etc). 1143 */ 1144 static void 1145 xbd_connect(struct xbd_softc *sc) 1146 { 1147 device_t dev = sc->xbd_dev; 1148 unsigned long sectors, sector_size; 1149 unsigned int binfo; 1150 int err, feature_barrier; 1151 1152 if ((sc->xbd_connected == XBD_STATE_CONNECTED) || 1153 (sc->xbd_connected == XBD_STATE_SUSPENDED)) 1154 return; 1155 1156 DPRINTK("blkfront.c:connect:%s.\n", xenbus_get_otherend_path(dev)); 1157 1158 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev), 1159 "sectors", "%lu", §ors, 1160 "info", "%u", &binfo, 1161 "sector-size", "%lu", §or_size, 1162 NULL); 1163 if (err) { 1164 xenbus_dev_fatal(dev, err, 1165 "reading backend fields at %s", 1166 xenbus_get_otherend_path(dev)); 1167 return; 1168 } 1169 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev), 1170 "feature-barrier", "%lu", &feature_barrier, 1171 NULL); 1172 if (!err || feature_barrier) 1173 sc->xbd_flags |= XBD_BARRIER; 1174 1175 if (sc->xbd_disk == NULL) { 1176 device_printf(dev, "%juMB <%s> at %s", 1177 (uintmax_t) sectors / (1048576 / sector_size), 1178 device_get_desc(dev), 1179 xenbus_get_node(dev)); 1180 bus_print_child_footer(device_get_parent(dev), dev); 1181 1182 xbd_instance_create(sc, sectors, sc->xbd_vdevice, binfo, 1183 sector_size); 1184 } 1185 1186 (void)xenbus_set_state(dev, XenbusStateConnected); 1187 1188 /* Kick pending requests. */ 1189 mtx_lock(&sc->xbd_io_lock); 1190 sc->xbd_connected = XBD_STATE_CONNECTED; 1191 xbd_startio(sc); 1192 sc->xbd_flags |= XBD_READY; 1193 mtx_unlock(&sc->xbd_io_lock); 1194 } 1195 1196 /** 1197 * Handle the change of state of the backend to Closing. We must delete our 1198 * device-layer structures now, to ensure that writes are flushed through to 1199 * the backend. Once this is done, we can switch to Closed in 1200 * acknowledgement. 1201 */ 1202 static void 1203 xbd_closing(device_t dev) 1204 { 1205 struct xbd_softc *sc = device_get_softc(dev); 1206 1207 xenbus_set_state(dev, XenbusStateClosing); 1208 1209 DPRINTK("xbd_closing: %s removed\n", xenbus_get_node(dev)); 1210 1211 if (sc->xbd_disk != NULL) { 1212 disk_destroy(sc->xbd_disk); 1213 sc->xbd_disk = NULL; 1214 } 1215 1216 xenbus_set_state(dev, XenbusStateClosed); 1217 } 1218 1219 /*---------------------------- NewBus Entrypoints ----------------------------*/ 1220 static int 1221 xbd_probe(device_t dev) 1222 { 1223 1224 if (!strcmp(xenbus_get_type(dev), "vbd")) { 1225 device_set_desc(dev, "Virtual Block Device"); 1226 device_quiet(dev); 1227 return (0); 1228 } 1229 1230 return (ENXIO); 1231 } 1232 1233 /* 1234 * Setup supplies the backend dir, virtual device. We place an event 1235 * channel and shared frame entries. We watch backend to wait if it's 1236 * ok. 1237 */ 1238 static int 1239 xbd_attach(device_t dev) 1240 { 1241 struct xbd_softc *sc; 1242 const char *name; 1243 uint32_t vdevice; 1244 int error; 1245 int i; 1246 int unit; 1247 1248 /* FIXME: Use dynamic device id if this is not set. */ 1249 error = xs_scanf(XST_NIL, xenbus_get_node(dev), 1250 "virtual-device", NULL, "%" PRIu32, &vdevice); 1251 if (error) { 1252 xenbus_dev_fatal(dev, error, "reading virtual-device"); 1253 device_printf(dev, "Couldn't determine virtual device.\n"); 1254 return (error); 1255 } 1256 1257 xbd_vdevice_to_unit(vdevice, &unit, &name); 1258 if (!strcmp(name, "xbd")) 1259 device_set_unit(dev, unit); 1260 1261 sc = device_get_softc(dev); 1262 mtx_init(&sc->xbd_io_lock, "blkfront i/o lock", NULL, MTX_DEF); 1263 xbd_initq_free(sc); 1264 xbd_initq_busy(sc); 1265 xbd_initq_ready(sc); 1266 xbd_initq_complete(sc); 1267 xbd_initq_bio(sc); 1268 for (i = 0; i < XBD_MAX_RING_PAGES; i++) 1269 sc->xbd_ring_ref[i] = GRANT_REF_INVALID; 1270 1271 sc->xbd_dev = dev; 1272 sc->xbd_vdevice = vdevice; 1273 sc->xbd_connected = XBD_STATE_DISCONNECTED; 1274 1275 xbd_setup_sysctl(sc); 1276 1277 /* Wait for backend device to publish its protocol capabilities. */ 1278 xenbus_set_state(dev, XenbusStateInitialising); 1279 1280 return (0); 1281 } 1282 1283 static int 1284 xbd_detach(device_t dev) 1285 { 1286 struct xbd_softc *sc = device_get_softc(dev); 1287 1288 DPRINTK("xbd_remove: %s removed\n", xenbus_get_node(dev)); 1289 1290 xbd_free(sc); 1291 mtx_destroy(&sc->xbd_io_lock); 1292 1293 return 0; 1294 } 1295 1296 static int 1297 xbd_suspend(device_t dev) 1298 { 1299 struct xbd_softc *sc = device_get_softc(dev); 1300 int retval; 1301 int saved_state; 1302 1303 /* Prevent new requests being issued until we fix things up. */ 1304 mtx_lock(&sc->xbd_io_lock); 1305 saved_state = sc->xbd_connected; 1306 sc->xbd_connected = XBD_STATE_SUSPENDED; 1307 1308 /* Wait for outstanding I/O to drain. */ 1309 retval = 0; 1310 while (TAILQ_EMPTY(&sc->xbd_cm_busy) == 0) { 1311 if (msleep(&sc->xbd_cm_busy, &sc->xbd_io_lock, 1312 PRIBIO, "blkf_susp", 30 * hz) == EWOULDBLOCK) { 1313 retval = EBUSY; 1314 break; 1315 } 1316 } 1317 mtx_unlock(&sc->xbd_io_lock); 1318 1319 if (retval != 0) 1320 sc->xbd_connected = saved_state; 1321 1322 return (retval); 1323 } 1324 1325 static int 1326 xbd_resume(device_t dev) 1327 { 1328 struct xbd_softc *sc = device_get_softc(dev); 1329 1330 DPRINTK("xbd_resume: %s\n", xenbus_get_node(dev)); 1331 1332 xbd_free(sc); 1333 xbd_initialize(sc); 1334 return (0); 1335 } 1336 1337 /** 1338 * Callback received when the backend's state changes. 1339 */ 1340 static void 1341 xbd_backend_changed(device_t dev, XenbusState backend_state) 1342 { 1343 struct xbd_softc *sc = device_get_softc(dev); 1344 1345 DPRINTK("backend_state=%d\n", backend_state); 1346 1347 switch (backend_state) { 1348 case XenbusStateUnknown: 1349 case XenbusStateInitialising: 1350 case XenbusStateReconfigured: 1351 case XenbusStateReconfiguring: 1352 case XenbusStateClosed: 1353 break; 1354 1355 case XenbusStateInitWait: 1356 case XenbusStateInitialised: 1357 xbd_initialize(sc); 1358 break; 1359 1360 case XenbusStateConnected: 1361 xbd_initialize(sc); 1362 xbd_connect(sc); 1363 break; 1364 1365 case XenbusStateClosing: 1366 if (sc->xbd_users > 0) 1367 xenbus_dev_error(dev, -EBUSY, 1368 "Device in use; refusing to close"); 1369 else 1370 xbd_closing(dev); 1371 break; 1372 } 1373 } 1374 1375 /*---------------------------- NewBus Registration ---------------------------*/ 1376 static device_method_t xbd_methods[] = { 1377 /* Device interface */ 1378 DEVMETHOD(device_probe, xbd_probe), 1379 DEVMETHOD(device_attach, xbd_attach), 1380 DEVMETHOD(device_detach, xbd_detach), 1381 DEVMETHOD(device_shutdown, bus_generic_shutdown), 1382 DEVMETHOD(device_suspend, xbd_suspend), 1383 DEVMETHOD(device_resume, xbd_resume), 1384 1385 /* Xenbus interface */ 1386 DEVMETHOD(xenbus_otherend_changed, xbd_backend_changed), 1387 1388 { 0, 0 } 1389 }; 1390 1391 static driver_t xbd_driver = { 1392 "xbd", 1393 xbd_methods, 1394 sizeof(struct xbd_softc), 1395 }; 1396 devclass_t xbd_devclass; 1397 1398 DRIVER_MODULE(xbd, xenbusb_front, xbd_driver, xbd_devclass, 0, 0); 1399