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 /* XXX move to xbd_vbd.c when VBD update support is added */ 85 #define MAX_VBDS 64 86 87 #define XBD_SECTOR_SIZE 512 /* XXX: assume for now */ 88 #define XBD_SECTOR_SHFT 9 89 90 #define GRANT_INVALID_REF 0 91 92 /* Control whether runtime update of vbds is enabled. */ 93 #define ENABLE_VBD_UPDATE 0 94 95 #if ENABLE_VBD_UPDATE 96 static void vbd_update(void); 97 #endif 98 99 #define XBD_STATE_DISCONNECTED 0 100 #define XBD_STATE_CONNECTED 1 101 #define XBD_STATE_SUSPENDED 2 102 103 /*---------------------------- Global Static Data ----------------------------*/ 104 static MALLOC_DEFINE(M_XENBLOCKFRONT, "xbd", "Xen Block Front driver data"); 105 106 /*---------------------------- Command Processing ----------------------------*/ 107 static inline void 108 xbd_flush_requests(struct xbd_softc *sc) 109 { 110 int notify; 111 112 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->xbd_ring, notify); 113 114 if (notify) 115 notify_remote_via_irq(sc->xbd_irq); 116 } 117 118 static void 119 xbd_free_command(struct xbd_command *cm) 120 { 121 122 KASSERT((cm->cm_flags & XBD_ON_XBDQ_MASK) == 0, 123 ("Freeing command that is still on a queue\n")); 124 125 cm->cm_flags = 0; 126 cm->cm_bp = NULL; 127 cm->cm_complete = NULL; 128 xbd_enqueue_free(cm); 129 } 130 131 static void 132 xbd_queue_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error) 133 { 134 struct xbd_softc *sc; 135 struct xbd_command *cm; 136 blkif_request_t *ring_req; 137 struct blkif_request_segment *sg; 138 struct blkif_request_segment *last_block_sg; 139 grant_ref_t *sg_ref; 140 vm_paddr_t buffer_ma; 141 uint64_t fsect, lsect; 142 int ref; 143 int op; 144 int block_segs; 145 146 cm = arg; 147 sc = cm->cm_sc; 148 149 if (error) { 150 printf("error %d in xbd_queue_cb\n", error); 151 cm->cm_bp->bio_error = EIO; 152 biodone(cm->cm_bp); 153 xbd_free_command(cm); 154 return; 155 } 156 157 /* Fill out a communications ring structure. */ 158 ring_req = RING_GET_REQUEST(&sc->xbd_ring, sc->xbd_ring.req_prod_pvt); 159 sc->xbd_ring.req_prod_pvt++; 160 ring_req->id = cm->cm_id; 161 ring_req->operation = cm->cm_operation; 162 ring_req->sector_number = cm->cm_sector_number; 163 ring_req->handle = (blkif_vdev_t)(uintptr_t)sc->xbd_disk; 164 ring_req->nr_segments = nsegs; 165 cm->cm_nseg = nsegs; 166 167 block_segs = MIN(nsegs, BLKIF_MAX_SEGMENTS_PER_HEADER_BLOCK); 168 sg = ring_req->seg; 169 last_block_sg = sg + block_segs; 170 sg_ref = cm->cm_sg_refs; 171 172 while (1) { 173 174 while (sg < last_block_sg) { 175 buffer_ma = segs->ds_addr; 176 fsect = (buffer_ma & PAGE_MASK) >> XBD_SECTOR_SHFT; 177 lsect = fsect + (segs->ds_len >> XBD_SECTOR_SHFT) - 1; 178 179 KASSERT(lsect <= 7, ("XEN disk driver data cannot " 180 "cross a page boundary")); 181 182 /* install a grant reference. */ 183 ref = gnttab_claim_grant_reference(&cm->cm_gref_head); 184 185 /* 186 * GNTTAB_LIST_END == 0xffffffff, but it is private 187 * to gnttab.c. 188 */ 189 KASSERT(ref != ~0, ("grant_reference failed")); 190 191 gnttab_grant_foreign_access_ref( 192 ref, 193 xenbus_get_otherend_id(sc->xbd_dev), 194 buffer_ma >> PAGE_SHIFT, 195 ring_req->operation == BLKIF_OP_WRITE); 196 197 *sg_ref = ref; 198 *sg = (struct blkif_request_segment) { 199 .gref = ref, 200 .first_sect = fsect, 201 .last_sect = lsect 202 }; 203 sg++; 204 sg_ref++; 205 segs++; 206 nsegs--; 207 } 208 block_segs = MIN(nsegs, BLKIF_MAX_SEGMENTS_PER_SEGMENT_BLOCK); 209 if (block_segs == 0) 210 break; 211 212 sg = BLKRING_GET_SEG_BLOCK(&sc->xbd_ring, 213 sc->xbd_ring.req_prod_pvt); 214 sc->xbd_ring.req_prod_pvt++; 215 last_block_sg = sg + block_segs; 216 } 217 218 if (cm->cm_operation == BLKIF_OP_READ) 219 op = BUS_DMASYNC_PREREAD; 220 else if (cm->cm_operation == BLKIF_OP_WRITE) 221 op = BUS_DMASYNC_PREWRITE; 222 else 223 op = 0; 224 bus_dmamap_sync(sc->xbd_io_dmat, cm->cm_map, op); 225 226 gnttab_free_grant_references(cm->cm_gref_head); 227 228 xbd_enqueue_busy(cm); 229 230 /* 231 * This flag means that we're probably executing in the busdma swi 232 * instead of in the startio context, so an explicit flush is needed. 233 */ 234 if (cm->cm_flags & XBD_CMD_FROZEN) 235 xbd_flush_requests(sc); 236 237 return; 238 } 239 240 static int 241 xbd_queue_request(struct xbd_softc *sc, struct xbd_command *cm) 242 { 243 int error; 244 245 error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map, cm->cm_data, 246 cm->cm_datalen, xbd_queue_cb, cm, 0); 247 if (error == EINPROGRESS) { 248 printf("EINPROGRESS\n"); 249 sc->xbd_flags |= XBD_FROZEN; 250 cm->cm_flags |= XBD_CMD_FROZEN; 251 return (0); 252 } 253 254 return (error); 255 } 256 257 static void 258 xbd_restart_queue_callback(void *arg) 259 { 260 struct xbd_softc *sc = arg; 261 262 mtx_lock(&sc->xbd_io_lock); 263 264 xbd_startio(sc); 265 266 mtx_unlock(&sc->xbd_io_lock); 267 } 268 269 static struct xbd_command * 270 xbd_bio_command(struct xbd_softc *sc) 271 { 272 struct xbd_command *cm; 273 struct bio *bp; 274 275 if (unlikely(sc->xbd_connected != XBD_STATE_CONNECTED)) 276 return (NULL); 277 278 bp = xbd_dequeue_bio(sc); 279 if (bp == NULL) 280 return (NULL); 281 282 if ((cm = xbd_dequeue_free(sc)) == NULL) { 283 xbd_requeue_bio(sc, bp); 284 return (NULL); 285 } 286 287 if (gnttab_alloc_grant_references(sc->xbd_max_request_segments, 288 &cm->cm_gref_head) != 0) { 289 gnttab_request_free_callback(&sc->xbd_callback, 290 xbd_restart_queue_callback, sc, 291 sc->xbd_max_request_segments); 292 xbd_requeue_bio(sc, bp); 293 xbd_enqueue_free(cm); 294 sc->xbd_flags |= XBD_FROZEN; 295 return (NULL); 296 } 297 298 cm->cm_bp = bp; 299 cm->cm_data = bp->bio_data; 300 cm->cm_datalen = bp->bio_bcount; 301 cm->cm_operation = (bp->bio_cmd == BIO_READ) ? 302 BLKIF_OP_READ : BLKIF_OP_WRITE; 303 cm->cm_sector_number = (blkif_sector_t)bp->bio_pblkno; 304 305 return (cm); 306 } 307 308 /* 309 * Dequeue buffers and place them in the shared communication ring. 310 * Return when no more requests can be accepted or all buffers have 311 * been queued. 312 * 313 * Signal XEN once the ring has been filled out. 314 */ 315 static void 316 xbd_startio(struct xbd_softc *sc) 317 { 318 struct xbd_command *cm; 319 int error, queued = 0; 320 321 mtx_assert(&sc->xbd_io_lock, MA_OWNED); 322 323 if (sc->xbd_connected != XBD_STATE_CONNECTED) 324 return; 325 326 while (RING_FREE_REQUESTS(&sc->xbd_ring) >= 327 sc->xbd_max_request_blocks) { 328 if (sc->xbd_flags & XBD_FROZEN) 329 break; 330 331 cm = xbd_dequeue_ready(sc); 332 333 if (cm == NULL) 334 cm = xbd_bio_command(sc); 335 336 if (cm == NULL) 337 break; 338 339 if ((error = xbd_queue_request(sc, cm)) != 0) { 340 printf("xbd_queue_request returned %d\n", error); 341 break; 342 } 343 queued++; 344 } 345 346 if (queued != 0) 347 xbd_flush_requests(sc); 348 } 349 350 static void 351 xbd_bio_complete(struct xbd_softc *sc, struct xbd_command *cm) 352 { 353 struct bio *bp; 354 355 bp = cm->cm_bp; 356 357 if (unlikely(cm->cm_status != BLKIF_RSP_OKAY)) { 358 disk_err(bp, "disk error" , -1, 0); 359 printf(" status: %x\n", cm->cm_status); 360 bp->bio_flags |= BIO_ERROR; 361 } 362 363 if (bp->bio_flags & BIO_ERROR) 364 bp->bio_error = EIO; 365 else 366 bp->bio_resid = 0; 367 368 xbd_free_command(cm); 369 biodone(bp); 370 } 371 372 static int 373 xbd_completion(struct xbd_command *cm) 374 { 375 gnttab_end_foreign_access_references(cm->cm_nseg, cm->cm_sg_refs); 376 return (BLKIF_SEGS_TO_BLOCKS(cm->cm_nseg)); 377 } 378 379 static void 380 xbd_int(void *xsc) 381 { 382 struct xbd_softc *sc = xsc; 383 struct xbd_command *cm; 384 blkif_response_t *bret; 385 RING_IDX i, rp; 386 int op; 387 388 mtx_lock(&sc->xbd_io_lock); 389 390 if (unlikely(sc->xbd_connected == XBD_STATE_DISCONNECTED)) { 391 mtx_unlock(&sc->xbd_io_lock); 392 return; 393 } 394 395 again: 396 rp = sc->xbd_ring.sring->rsp_prod; 397 rmb(); /* Ensure we see queued responses up to 'rp'. */ 398 399 for (i = sc->xbd_ring.rsp_cons; i != rp;) { 400 bret = RING_GET_RESPONSE(&sc->xbd_ring, i); 401 cm = &sc->xbd_shadow[bret->id]; 402 403 xbd_remove_busy(cm); 404 i += xbd_completion(cm); 405 406 if (cm->cm_operation == BLKIF_OP_READ) 407 op = BUS_DMASYNC_POSTREAD; 408 else if (cm->cm_operation == BLKIF_OP_WRITE) 409 op = BUS_DMASYNC_POSTWRITE; 410 else 411 op = 0; 412 bus_dmamap_sync(sc->xbd_io_dmat, cm->cm_map, op); 413 bus_dmamap_unload(sc->xbd_io_dmat, cm->cm_map); 414 415 /* 416 * If commands are completing then resources are probably 417 * being freed as well. It's a cheap assumption even when 418 * wrong. 419 */ 420 sc->xbd_flags &= ~XBD_FROZEN; 421 422 /* 423 * Directly call the i/o complete routine to save an 424 * an indirection in the common case. 425 */ 426 cm->cm_status = bret->status; 427 if (cm->cm_bp) 428 xbd_bio_complete(sc, cm); 429 else if (cm->cm_complete != NULL) 430 cm->cm_complete(cm); 431 else 432 xbd_free_command(cm); 433 } 434 435 sc->xbd_ring.rsp_cons = i; 436 437 if (i != sc->xbd_ring.req_prod_pvt) { 438 int more_to_do; 439 RING_FINAL_CHECK_FOR_RESPONSES(&sc->xbd_ring, more_to_do); 440 if (more_to_do) 441 goto again; 442 } else { 443 sc->xbd_ring.sring->rsp_event = i + 1; 444 } 445 446 xbd_startio(sc); 447 448 if (unlikely(sc->xbd_connected == XBD_STATE_SUSPENDED)) 449 wakeup(&sc->xbd_cm_busy); 450 451 mtx_unlock(&sc->xbd_io_lock); 452 } 453 454 /*------------------------------- Dump Support -------------------------------*/ 455 /** 456 * Quiesce the disk writes for a dump file before allowing the next buffer. 457 */ 458 static void 459 xbd_quiesce(struct xbd_softc *sc) 460 { 461 int mtd; 462 463 // While there are outstanding requests 464 while (!TAILQ_EMPTY(&sc->xbd_cm_busy)) { 465 RING_FINAL_CHECK_FOR_RESPONSES(&sc->xbd_ring, mtd); 466 if (mtd) { 467 /* Recieved request completions, update queue. */ 468 xbd_int(sc); 469 } 470 if (!TAILQ_EMPTY(&sc->xbd_cm_busy)) { 471 /* 472 * Still pending requests, wait for the disk i/o 473 * to complete. 474 */ 475 HYPERVISOR_yield(); 476 } 477 } 478 } 479 480 /* Kernel dump function for a paravirtualized disk device */ 481 static void 482 xbd_dump_complete(struct xbd_command *cm) 483 { 484 485 xbd_enqueue_complete(cm); 486 } 487 488 static int 489 xbd_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 490 size_t length) 491 { 492 struct disk *dp = arg; 493 struct xbd_softc *sc = dp->d_drv1; 494 struct xbd_command *cm; 495 size_t chunk; 496 int sbp; 497 int rc = 0; 498 499 if (length <= 0) 500 return (rc); 501 502 xbd_quiesce(sc); /* All quiet on the western front. */ 503 504 /* 505 * If this lock is held, then this module is failing, and a 506 * successful kernel dump is highly unlikely anyway. 507 */ 508 mtx_lock(&sc->xbd_io_lock); 509 510 /* Split the 64KB block as needed */ 511 for (sbp=0; length > 0; sbp++) { 512 cm = xbd_dequeue_free(sc); 513 if (cm == NULL) { 514 mtx_unlock(&sc->xbd_io_lock); 515 device_printf(sc->xbd_dev, "dump: no more commands?\n"); 516 return (EBUSY); 517 } 518 519 if (gnttab_alloc_grant_references(sc->xbd_max_request_segments, 520 &cm->cm_gref_head) != 0) { 521 xbd_free_command(cm); 522 mtx_unlock(&sc->xbd_io_lock); 523 device_printf(sc->xbd_dev, "no more grant allocs?\n"); 524 return (EBUSY); 525 } 526 527 chunk = length > sc->xbd_max_request_size ? 528 sc->xbd_max_request_size : length; 529 cm->cm_data = virtual; 530 cm->cm_datalen = chunk; 531 cm->cm_operation = BLKIF_OP_WRITE; 532 cm->cm_sector_number = offset / dp->d_sectorsize; 533 cm->cm_complete = xbd_dump_complete; 534 535 xbd_enqueue_ready(cm); 536 537 length -= chunk; 538 offset += chunk; 539 virtual = (char *) virtual + chunk; 540 } 541 542 /* Tell DOM0 to do the I/O */ 543 xbd_startio(sc); 544 mtx_unlock(&sc->xbd_io_lock); 545 546 /* Poll for the completion. */ 547 xbd_quiesce(sc); /* All quite on the eastern front */ 548 549 /* If there were any errors, bail out... */ 550 while ((cm = xbd_dequeue_complete(sc)) != NULL) { 551 if (cm->cm_status != BLKIF_RSP_OKAY) { 552 device_printf(sc->xbd_dev, 553 "Dump I/O failed at sector %jd\n", 554 cm->cm_sector_number); 555 rc = EIO; 556 } 557 xbd_free_command(cm); 558 } 559 560 return (rc); 561 } 562 563 /*----------------------------- Disk Entrypoints -----------------------------*/ 564 static int 565 xbd_open(struct disk *dp) 566 { 567 struct xbd_softc *sc = dp->d_drv1; 568 569 if (sc == NULL) { 570 printf("xb%d: not found", sc->xbd_unit); 571 return (ENXIO); 572 } 573 574 sc->xbd_flags |= XBD_OPEN; 575 sc->xbd_users++; 576 return (0); 577 } 578 579 static int 580 xbd_close(struct disk *dp) 581 { 582 struct xbd_softc *sc = dp->d_drv1; 583 584 if (sc == NULL) 585 return (ENXIO); 586 sc->xbd_flags &= ~XBD_OPEN; 587 if (--(sc->xbd_users) == 0) { 588 /* 589 * Check whether we have been instructed to close. We will 590 * have ignored this request initially, as the device was 591 * still mounted. 592 */ 593 if (xenbus_get_otherend_state(sc->xbd_dev) == 594 XenbusStateClosing) 595 xbd_closing(sc->xbd_dev); 596 } 597 return (0); 598 } 599 600 static int 601 xbd_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, struct thread *td) 602 { 603 struct xbd_softc *sc = dp->d_drv1; 604 605 if (sc == NULL) 606 return (ENXIO); 607 608 return (ENOTTY); 609 } 610 611 /* 612 * Read/write routine for a buffer. Finds the proper unit, place it on 613 * the sortq and kick the controller. 614 */ 615 static void 616 xbd_strategy(struct bio *bp) 617 { 618 struct xbd_softc *sc = bp->bio_disk->d_drv1; 619 620 /* bogus disk? */ 621 if (sc == NULL) { 622 bp->bio_error = EINVAL; 623 bp->bio_flags |= BIO_ERROR; 624 bp->bio_resid = bp->bio_bcount; 625 biodone(bp); 626 return; 627 } 628 629 /* 630 * Place it in the queue of disk activities for this disk 631 */ 632 mtx_lock(&sc->xbd_io_lock); 633 634 xbd_enqueue_bio(sc, bp); 635 xbd_startio(sc); 636 637 mtx_unlock(&sc->xbd_io_lock); 638 return; 639 } 640 641 /*------------------------------ Ring Management -----------------------------*/ 642 static int 643 xbd_alloc_ring(struct xbd_softc *sc) 644 { 645 blkif_sring_t *sring; 646 uintptr_t sring_page_addr; 647 int error; 648 int i; 649 650 sring = malloc(sc->xbd_ring_pages * PAGE_SIZE, M_XENBLOCKFRONT, 651 M_NOWAIT|M_ZERO); 652 if (sring == NULL) { 653 xenbus_dev_fatal(sc->xbd_dev, ENOMEM, "allocating shared ring"); 654 return (ENOMEM); 655 } 656 SHARED_RING_INIT(sring); 657 FRONT_RING_INIT(&sc->xbd_ring, sring, sc->xbd_ring_pages * PAGE_SIZE); 658 659 for (i = 0, sring_page_addr = (uintptr_t)sring; 660 i < sc->xbd_ring_pages; 661 i++, sring_page_addr += PAGE_SIZE) { 662 663 error = xenbus_grant_ring(sc->xbd_dev, 664 (vtomach(sring_page_addr) >> PAGE_SHIFT), 665 &sc->xbd_ring_ref[i]); 666 if (error) { 667 xenbus_dev_fatal(sc->xbd_dev, error, 668 "granting ring_ref(%d)", i); 669 return (error); 670 } 671 } 672 if (sc->xbd_ring_pages == 1) { 673 error = xs_printf(XST_NIL, xenbus_get_node(sc->xbd_dev), 674 "ring-ref", "%u", sc->xbd_ring_ref[0]); 675 if (error) { 676 xenbus_dev_fatal(sc->xbd_dev, error, 677 "writing %s/ring-ref", 678 xenbus_get_node(sc->xbd_dev)); 679 return (error); 680 } 681 } else { 682 for (i = 0; i < sc->xbd_ring_pages; i++) { 683 char ring_ref_name[]= "ring_refXX"; 684 685 snprintf(ring_ref_name, sizeof(ring_ref_name), 686 "ring-ref%u", i); 687 error = xs_printf(XST_NIL, xenbus_get_node(sc->xbd_dev), 688 ring_ref_name, "%u", sc->xbd_ring_ref[i]); 689 if (error) { 690 xenbus_dev_fatal(sc->xbd_dev, error, 691 "writing %s/%s", 692 xenbus_get_node(sc->xbd_dev), 693 ring_ref_name); 694 return (error); 695 } 696 } 697 } 698 699 error = bind_listening_port_to_irqhandler( 700 xenbus_get_otherend_id(sc->xbd_dev), 701 "xbd", (driver_intr_t *)xbd_int, sc, 702 INTR_TYPE_BIO | INTR_MPSAFE, &sc->xbd_irq); 703 if (error) { 704 xenbus_dev_fatal(sc->xbd_dev, error, 705 "bind_evtchn_to_irqhandler failed"); 706 return (error); 707 } 708 709 return (0); 710 } 711 712 /*-------------------------- Initialization/Teardown -------------------------*/ 713 static void 714 xbd_setup_sysctl(struct xbd_softc *xbd) 715 { 716 struct sysctl_ctx_list *sysctl_ctx = NULL; 717 struct sysctl_oid *sysctl_tree = NULL; 718 719 sysctl_ctx = device_get_sysctl_ctx(xbd->xbd_dev); 720 if (sysctl_ctx == NULL) 721 return; 722 723 sysctl_tree = device_get_sysctl_tree(xbd->xbd_dev); 724 if (sysctl_tree == NULL) 725 return; 726 727 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 728 "max_requests", CTLFLAG_RD, &xbd->xbd_max_requests, -1, 729 "maximum outstanding requests (negotiated)"); 730 731 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 732 "max_request_segments", CTLFLAG_RD, 733 &xbd->xbd_max_request_segments, 0, 734 "maximum number of pages per requests (negotiated)"); 735 736 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 737 "max_request_size", CTLFLAG_RD, &xbd->xbd_max_request_size, 0, 738 "maximum size in bytes of a request (negotiated)"); 739 740 SYSCTL_ADD_UINT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO, 741 "ring_pages", CTLFLAG_RD, &xbd->xbd_ring_pages, 0, 742 "communication channel pages (negotiated)"); 743 } 744 745 /* 746 * Translate Linux major/minor to an appropriate name and unit 747 * number. For HVM guests, this allows us to use the same drive names 748 * with blkfront as the emulated drives, easing transition slightly. 749 */ 750 static void 751 xbd_vdevice_to_unit(uint32_t vdevice, int *unit, const char **name) 752 { 753 static struct vdev_info { 754 int major; 755 int shift; 756 int base; 757 const char *name; 758 } info[] = { 759 {3, 6, 0, "ada"}, /* ide0 */ 760 {22, 6, 2, "ada"}, /* ide1 */ 761 {33, 6, 4, "ada"}, /* ide2 */ 762 {34, 6, 6, "ada"}, /* ide3 */ 763 {56, 6, 8, "ada"}, /* ide4 */ 764 {57, 6, 10, "ada"}, /* ide5 */ 765 {88, 6, 12, "ada"}, /* ide6 */ 766 {89, 6, 14, "ada"}, /* ide7 */ 767 {90, 6, 16, "ada"}, /* ide8 */ 768 {91, 6, 18, "ada"}, /* ide9 */ 769 770 {8, 4, 0, "da"}, /* scsi disk0 */ 771 {65, 4, 16, "da"}, /* scsi disk1 */ 772 {66, 4, 32, "da"}, /* scsi disk2 */ 773 {67, 4, 48, "da"}, /* scsi disk3 */ 774 {68, 4, 64, "da"}, /* scsi disk4 */ 775 {69, 4, 80, "da"}, /* scsi disk5 */ 776 {70, 4, 96, "da"}, /* scsi disk6 */ 777 {71, 4, 112, "da"}, /* scsi disk7 */ 778 {128, 4, 128, "da"}, /* scsi disk8 */ 779 {129, 4, 144, "da"}, /* scsi disk9 */ 780 {130, 4, 160, "da"}, /* scsi disk10 */ 781 {131, 4, 176, "da"}, /* scsi disk11 */ 782 {132, 4, 192, "da"}, /* scsi disk12 */ 783 {133, 4, 208, "da"}, /* scsi disk13 */ 784 {134, 4, 224, "da"}, /* scsi disk14 */ 785 {135, 4, 240, "da"}, /* scsi disk15 */ 786 787 {202, 4, 0, "xbd"}, /* xbd */ 788 789 {0, 0, 0, NULL}, 790 }; 791 int major = vdevice >> 8; 792 int minor = vdevice & 0xff; 793 int i; 794 795 if (vdevice & (1 << 28)) { 796 *unit = (vdevice & ((1 << 28) - 1)) >> 8; 797 *name = "xbd"; 798 return; 799 } 800 801 for (i = 0; info[i].major; i++) { 802 if (info[i].major == major) { 803 *unit = info[i].base + (minor >> info[i].shift); 804 *name = info[i].name; 805 return; 806 } 807 } 808 809 *unit = minor >> 4; 810 *name = "xbd"; 811 } 812 813 int 814 xbd_instance_create(struct xbd_softc *sc, blkif_sector_t sectors, 815 int vdevice, uint16_t vdisk_info, unsigned long sector_size) 816 { 817 int unit, error = 0; 818 const char *name; 819 820 xbd_vdevice_to_unit(vdevice, &unit, &name); 821 822 sc->xbd_unit = unit; 823 824 if (strcmp(name, "xbd")) 825 device_printf(sc->xbd_dev, "attaching as %s%d\n", name, unit); 826 827 sc->xbd_disk = disk_alloc(); 828 sc->xbd_disk->d_unit = sc->xbd_unit; 829 sc->xbd_disk->d_open = xbd_open; 830 sc->xbd_disk->d_close = xbd_close; 831 sc->xbd_disk->d_ioctl = xbd_ioctl; 832 sc->xbd_disk->d_strategy = xbd_strategy; 833 sc->xbd_disk->d_dump = xbd_dump; 834 sc->xbd_disk->d_name = name; 835 sc->xbd_disk->d_drv1 = sc; 836 sc->xbd_disk->d_sectorsize = sector_size; 837 838 sc->xbd_disk->d_mediasize = sectors * sector_size; 839 sc->xbd_disk->d_maxsize = sc->xbd_max_request_size; 840 sc->xbd_disk->d_flags = 0; 841 disk_create(sc->xbd_disk, DISK_VERSION); 842 843 return error; 844 } 845 846 static void 847 xbd_free(struct xbd_softc *sc) 848 { 849 uint8_t *sring_page_ptr; 850 int i; 851 852 /* Prevent new requests being issued until we fix things up. */ 853 mtx_lock(&sc->xbd_io_lock); 854 sc->xbd_connected = XBD_STATE_DISCONNECTED; 855 mtx_unlock(&sc->xbd_io_lock); 856 857 /* Free resources associated with old device channel. */ 858 if (sc->xbd_ring.sring != NULL) { 859 sring_page_ptr = (uint8_t *)sc->xbd_ring.sring; 860 for (i = 0; i < sc->xbd_ring_pages; i++) { 861 grant_ref_t *ref; 862 863 ref = &sc->xbd_ring_ref[i]; 864 if (*ref != GRANT_INVALID_REF) { 865 gnttab_end_foreign_access_ref(*ref); 866 *ref = GRANT_INVALID_REF; 867 } 868 sring_page_ptr += PAGE_SIZE; 869 } 870 free(sc->xbd_ring.sring, M_XENBLOCKFRONT); 871 sc->xbd_ring.sring = NULL; 872 } 873 874 if (sc->xbd_shadow) { 875 876 for (i = 0; i < sc->xbd_max_requests; i++) { 877 struct xbd_command *cm; 878 879 cm = &sc->xbd_shadow[i]; 880 if (cm->cm_sg_refs != NULL) { 881 free(cm->cm_sg_refs, M_XENBLOCKFRONT); 882 cm->cm_sg_refs = NULL; 883 } 884 885 bus_dmamap_destroy(sc->xbd_io_dmat, cm->cm_map); 886 } 887 free(sc->xbd_shadow, M_XENBLOCKFRONT); 888 sc->xbd_shadow = NULL; 889 890 bus_dma_tag_destroy(sc->xbd_io_dmat); 891 892 xbd_initq_free(sc); 893 xbd_initq_ready(sc); 894 xbd_initq_complete(sc); 895 } 896 897 if (sc->xbd_irq) { 898 unbind_from_irqhandler(sc->xbd_irq); 899 sc->xbd_irq = 0; 900 } 901 } 902 903 /*--------------------------- State Change Handlers --------------------------*/ 904 static void 905 xbd_initialize(struct xbd_softc *sc) 906 { 907 const char *otherend_path; 908 const char *node_path; 909 uint32_t max_ring_page_order; 910 int error; 911 int i; 912 913 if (xenbus_get_state(sc->xbd_dev) != XenbusStateInitialising) { 914 /* Initialization has already been performed. */ 915 return; 916 } 917 918 /* 919 * Protocol defaults valid even if negotiation for a 920 * setting fails. 921 */ 922 max_ring_page_order = 0; 923 sc->xbd_ring_pages = 1; 924 sc->xbd_max_request_segments = BLKIF_MAX_SEGMENTS_PER_HEADER_BLOCK; 925 sc->xbd_max_request_size = 926 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments); 927 sc->xbd_max_request_blocks = 928 BLKIF_SEGS_TO_BLOCKS(sc->xbd_max_request_segments); 929 930 /* 931 * Protocol negotiation. 932 * 933 * \note xs_gather() returns on the first encountered error, so 934 * we must use independant calls in order to guarantee 935 * we don't miss information in a sparsly populated back-end 936 * tree. 937 * 938 * \note xs_scanf() does not update variables for unmatched 939 * fields. 940 */ 941 otherend_path = xenbus_get_otherend_path(sc->xbd_dev); 942 node_path = xenbus_get_node(sc->xbd_dev); 943 944 /* Support both backend schemes for relaying ring page limits. */ 945 (void)xs_scanf(XST_NIL, otherend_path, 946 "max-ring-page-order", NULL, "%" PRIu32, 947 &max_ring_page_order); 948 sc->xbd_ring_pages = 1 << max_ring_page_order; 949 (void)xs_scanf(XST_NIL, otherend_path, 950 "max-ring-pages", NULL, "%" PRIu32, 951 &sc->xbd_ring_pages); 952 if (sc->xbd_ring_pages < 1) 953 sc->xbd_ring_pages = 1; 954 955 sc->xbd_max_requests = 956 BLKIF_MAX_RING_REQUESTS(sc->xbd_ring_pages * PAGE_SIZE); 957 (void)xs_scanf(XST_NIL, otherend_path, 958 "max-requests", NULL, "%" PRIu32, 959 &sc->xbd_max_requests); 960 961 (void)xs_scanf(XST_NIL, otherend_path, 962 "max-request-segments", NULL, "%" PRIu32, 963 &sc->xbd_max_request_segments); 964 965 (void)xs_scanf(XST_NIL, otherend_path, 966 "max-request-size", NULL, "%" PRIu32, 967 &sc->xbd_max_request_size); 968 969 if (sc->xbd_ring_pages > XBD_MAX_RING_PAGES) { 970 device_printf(sc->xbd_dev, 971 "Back-end specified ring-pages of %u " 972 "limited to front-end limit of %zu.\n", 973 sc->xbd_ring_pages, XBD_MAX_RING_PAGES); 974 sc->xbd_ring_pages = XBD_MAX_RING_PAGES; 975 } 976 977 if (powerof2(sc->xbd_ring_pages) == 0) { 978 uint32_t new_page_limit; 979 980 new_page_limit = 0x01 << (fls(sc->xbd_ring_pages) - 1); 981 device_printf(sc->xbd_dev, 982 "Back-end specified ring-pages of %u " 983 "is not a power of 2. Limited to %u.\n", 984 sc->xbd_ring_pages, new_page_limit); 985 sc->xbd_ring_pages = new_page_limit; 986 } 987 988 if (sc->xbd_max_requests > XBD_MAX_REQUESTS) { 989 device_printf(sc->xbd_dev, 990 "Back-end specified max_requests of %u " 991 "limited to front-end limit of %u.\n", 992 sc->xbd_max_requests, XBD_MAX_REQUESTS); 993 sc->xbd_max_requests = XBD_MAX_REQUESTS; 994 } 995 996 if (sc->xbd_max_request_segments > XBD_MAX_SEGMENTS_PER_REQUEST) { 997 device_printf(sc->xbd_dev, 998 "Back-end specified max_request_segments of %u " 999 "limited to front-end limit of %u.\n", 1000 sc->xbd_max_request_segments, 1001 XBD_MAX_SEGMENTS_PER_REQUEST); 1002 sc->xbd_max_request_segments = XBD_MAX_SEGMENTS_PER_REQUEST; 1003 } 1004 1005 if (sc->xbd_max_request_size > XBD_MAX_REQUEST_SIZE) { 1006 device_printf(sc->xbd_dev, 1007 "Back-end specified max_request_size of %u " 1008 "limited to front-end limit of %u.\n", 1009 sc->xbd_max_request_size, 1010 XBD_MAX_REQUEST_SIZE); 1011 sc->xbd_max_request_size = XBD_MAX_REQUEST_SIZE; 1012 } 1013 1014 if (sc->xbd_max_request_size > 1015 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments)) { 1016 device_printf(sc->xbd_dev, 1017 "Back-end specified max_request_size of %u " 1018 "limited to front-end limit of %u. (Too few segments.)\n", 1019 sc->xbd_max_request_size, 1020 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments)); 1021 sc->xbd_max_request_size = 1022 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments); 1023 } 1024 1025 sc->xbd_max_request_blocks = 1026 BLKIF_SEGS_TO_BLOCKS(sc->xbd_max_request_segments); 1027 1028 /* Allocate datastructures based on negotiated values. */ 1029 error = bus_dma_tag_create( 1030 bus_get_dma_tag(sc->xbd_dev), /* parent */ 1031 512, PAGE_SIZE, /* algnmnt, boundary */ 1032 BUS_SPACE_MAXADDR, /* lowaddr */ 1033 BUS_SPACE_MAXADDR, /* highaddr */ 1034 NULL, NULL, /* filter, filterarg */ 1035 sc->xbd_max_request_size, 1036 sc->xbd_max_request_segments, 1037 PAGE_SIZE, /* maxsegsize */ 1038 BUS_DMA_ALLOCNOW, /* flags */ 1039 busdma_lock_mutex, /* lockfunc */ 1040 &sc->xbd_io_lock, /* lockarg */ 1041 &sc->xbd_io_dmat); 1042 if (error != 0) { 1043 xenbus_dev_fatal(sc->xbd_dev, error, 1044 "Cannot allocate parent DMA tag\n"); 1045 return; 1046 } 1047 1048 /* Per-transaction data allocation. */ 1049 sc->xbd_shadow = malloc(sizeof(*sc->xbd_shadow) * sc->xbd_max_requests, 1050 M_XENBLOCKFRONT, M_NOWAIT|M_ZERO); 1051 if (sc->xbd_shadow == NULL) { 1052 bus_dma_tag_destroy(sc->xbd_io_dmat); 1053 xenbus_dev_fatal(sc->xbd_dev, error, 1054 "Cannot allocate request structures\n"); 1055 return; 1056 } 1057 1058 for (i = 0; i < sc->xbd_max_requests; i++) { 1059 struct xbd_command *cm; 1060 1061 cm = &sc->xbd_shadow[i]; 1062 cm->cm_sg_refs = malloc( 1063 sizeof(grant_ref_t) * sc->xbd_max_request_segments, 1064 M_XENBLOCKFRONT, M_NOWAIT); 1065 if (cm->cm_sg_refs == NULL) 1066 break; 1067 cm->cm_id = i; 1068 cm->cm_sc = sc; 1069 if (bus_dmamap_create(sc->xbd_io_dmat, 0, &cm->cm_map) != 0) 1070 break; 1071 xbd_free_command(cm); 1072 } 1073 1074 if (xbd_alloc_ring(sc) != 0) 1075 return; 1076 1077 /* Support both backend schemes for relaying ring page limits. */ 1078 if (sc->xbd_ring_pages > 1) { 1079 error = xs_printf(XST_NIL, node_path, 1080 "num-ring-pages","%u", 1081 sc->xbd_ring_pages); 1082 if (error) { 1083 xenbus_dev_fatal(sc->xbd_dev, error, 1084 "writing %s/num-ring-pages", 1085 node_path); 1086 return; 1087 } 1088 1089 error = xs_printf(XST_NIL, node_path, 1090 "ring-page-order", "%u", 1091 fls(sc->xbd_ring_pages) - 1); 1092 if (error) { 1093 xenbus_dev_fatal(sc->xbd_dev, error, 1094 "writing %s/ring-page-order", 1095 node_path); 1096 return; 1097 } 1098 } 1099 1100 error = xs_printf(XST_NIL, node_path, 1101 "max-requests","%u", 1102 sc->xbd_max_requests); 1103 if (error) { 1104 xenbus_dev_fatal(sc->xbd_dev, error, 1105 "writing %s/max-requests", 1106 node_path); 1107 return; 1108 } 1109 1110 error = xs_printf(XST_NIL, node_path, 1111 "max-request-segments","%u", 1112 sc->xbd_max_request_segments); 1113 if (error) { 1114 xenbus_dev_fatal(sc->xbd_dev, error, 1115 "writing %s/max-request-segments", 1116 node_path); 1117 return; 1118 } 1119 1120 error = xs_printf(XST_NIL, node_path, 1121 "max-request-size","%u", 1122 sc->xbd_max_request_size); 1123 if (error) { 1124 xenbus_dev_fatal(sc->xbd_dev, error, 1125 "writing %s/max-request-size", 1126 node_path); 1127 return; 1128 } 1129 1130 error = xs_printf(XST_NIL, node_path, "event-channel", 1131 "%u", irq_to_evtchn_port(sc->xbd_irq)); 1132 if (error) { 1133 xenbus_dev_fatal(sc->xbd_dev, error, 1134 "writing %s/event-channel", 1135 node_path); 1136 return; 1137 } 1138 1139 error = xs_printf(XST_NIL, node_path, "protocol", 1140 "%s", XEN_IO_PROTO_ABI_NATIVE); 1141 if (error) { 1142 xenbus_dev_fatal(sc->xbd_dev, error, 1143 "writing %s/protocol", 1144 node_path); 1145 return; 1146 } 1147 1148 xenbus_set_state(sc->xbd_dev, XenbusStateInitialised); 1149 } 1150 1151 /* 1152 * Invoked when the backend is finally 'ready' (and has published 1153 * the details about the physical device - #sectors, size, etc). 1154 */ 1155 static void 1156 xbd_connect(struct xbd_softc *sc) 1157 { 1158 device_t dev = sc->xbd_dev; 1159 unsigned long sectors, sector_size; 1160 unsigned int binfo; 1161 int err, feature_barrier; 1162 1163 if ((sc->xbd_connected == XBD_STATE_CONNECTED) || 1164 (sc->xbd_connected == XBD_STATE_SUSPENDED)) 1165 return; 1166 1167 DPRINTK("blkfront.c:connect:%s.\n", xenbus_get_otherend_path(dev)); 1168 1169 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev), 1170 "sectors", "%lu", §ors, 1171 "info", "%u", &binfo, 1172 "sector-size", "%lu", §or_size, 1173 NULL); 1174 if (err) { 1175 xenbus_dev_fatal(dev, err, 1176 "reading backend fields at %s", 1177 xenbus_get_otherend_path(dev)); 1178 return; 1179 } 1180 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev), 1181 "feature-barrier", "%lu", &feature_barrier, 1182 NULL); 1183 if (!err || feature_barrier) 1184 sc->xbd_flags |= XBD_BARRIER; 1185 1186 if (sc->xbd_disk == NULL) { 1187 device_printf(dev, "%juMB <%s> at %s", 1188 (uintmax_t) sectors / (1048576 / sector_size), 1189 device_get_desc(dev), 1190 xenbus_get_node(dev)); 1191 bus_print_child_footer(device_get_parent(dev), dev); 1192 1193 xbd_instance_create(sc, sectors, sc->xbd_vdevice, binfo, 1194 sector_size); 1195 } 1196 1197 (void)xenbus_set_state(dev, XenbusStateConnected); 1198 1199 /* Kick pending requests. */ 1200 mtx_lock(&sc->xbd_io_lock); 1201 sc->xbd_connected = XBD_STATE_CONNECTED; 1202 xbd_startio(sc); 1203 sc->xbd_flags |= XBD_READY; 1204 mtx_unlock(&sc->xbd_io_lock); 1205 } 1206 1207 /** 1208 * Handle the change of state of the backend to Closing. We must delete our 1209 * device-layer structures now, to ensure that writes are flushed through to 1210 * the backend. Once this is done, we can switch to Closed in 1211 * acknowledgement. 1212 */ 1213 static void 1214 xbd_closing(device_t dev) 1215 { 1216 struct xbd_softc *sc = device_get_softc(dev); 1217 1218 xenbus_set_state(dev, XenbusStateClosing); 1219 1220 DPRINTK("xbd_closing: %s removed\n", xenbus_get_node(dev)); 1221 1222 if (sc->xbd_disk != NULL) { 1223 disk_destroy(sc->xbd_disk); 1224 sc->xbd_disk = NULL; 1225 } 1226 1227 xenbus_set_state(dev, XenbusStateClosed); 1228 } 1229 1230 /*---------------------------- NewBus Entrypoints ----------------------------*/ 1231 static int 1232 xbd_probe(device_t dev) 1233 { 1234 1235 if (!strcmp(xenbus_get_type(dev), "vbd")) { 1236 device_set_desc(dev, "Virtual Block Device"); 1237 device_quiet(dev); 1238 return (0); 1239 } 1240 1241 return (ENXIO); 1242 } 1243 1244 /* 1245 * Setup supplies the backend dir, virtual device. We place an event 1246 * channel and shared frame entries. We watch backend to wait if it's 1247 * ok. 1248 */ 1249 static int 1250 xbd_attach(device_t dev) 1251 { 1252 struct xbd_softc *sc; 1253 const char *name; 1254 uint32_t vdevice; 1255 int error; 1256 int i; 1257 int unit; 1258 1259 /* FIXME: Use dynamic device id if this is not set. */ 1260 error = xs_scanf(XST_NIL, xenbus_get_node(dev), 1261 "virtual-device", NULL, "%" PRIu32, &vdevice); 1262 if (error) { 1263 xenbus_dev_fatal(dev, error, "reading virtual-device"); 1264 device_printf(dev, "Couldn't determine virtual device.\n"); 1265 return (error); 1266 } 1267 1268 xbd_vdevice_to_unit(vdevice, &unit, &name); 1269 if (!strcmp(name, "xbd")) 1270 device_set_unit(dev, unit); 1271 1272 sc = device_get_softc(dev); 1273 mtx_init(&sc->xbd_io_lock, "blkfront i/o lock", NULL, MTX_DEF); 1274 xbd_initq_free(sc); 1275 xbd_initq_busy(sc); 1276 xbd_initq_ready(sc); 1277 xbd_initq_complete(sc); 1278 xbd_initq_bio(sc); 1279 for (i = 0; i < XBD_MAX_RING_PAGES; i++) 1280 sc->xbd_ring_ref[i] = GRANT_INVALID_REF; 1281 1282 sc->xbd_dev = dev; 1283 sc->xbd_vdevice = vdevice; 1284 sc->xbd_connected = XBD_STATE_DISCONNECTED; 1285 1286 xbd_setup_sysctl(sc); 1287 1288 /* Wait for backend device to publish its protocol capabilities. */ 1289 xenbus_set_state(dev, XenbusStateInitialising); 1290 1291 return (0); 1292 } 1293 1294 static int 1295 xbd_detach(device_t dev) 1296 { 1297 struct xbd_softc *sc = device_get_softc(dev); 1298 1299 DPRINTK("xbd_remove: %s removed\n", xenbus_get_node(dev)); 1300 1301 xbd_free(sc); 1302 mtx_destroy(&sc->xbd_io_lock); 1303 1304 return 0; 1305 } 1306 1307 static int 1308 xbd_suspend(device_t dev) 1309 { 1310 struct xbd_softc *sc = device_get_softc(dev); 1311 int retval; 1312 int saved_state; 1313 1314 /* Prevent new requests being issued until we fix things up. */ 1315 mtx_lock(&sc->xbd_io_lock); 1316 saved_state = sc->xbd_connected; 1317 sc->xbd_connected = XBD_STATE_SUSPENDED; 1318 1319 /* Wait for outstanding I/O to drain. */ 1320 retval = 0; 1321 while (TAILQ_EMPTY(&sc->xbd_cm_busy) == 0) { 1322 if (msleep(&sc->xbd_cm_busy, &sc->xbd_io_lock, 1323 PRIBIO, "blkf_susp", 30 * hz) == EWOULDBLOCK) { 1324 retval = EBUSY; 1325 break; 1326 } 1327 } 1328 mtx_unlock(&sc->xbd_io_lock); 1329 1330 if (retval != 0) 1331 sc->xbd_connected = saved_state; 1332 1333 return (retval); 1334 } 1335 1336 static int 1337 xbd_resume(device_t dev) 1338 { 1339 struct xbd_softc *sc = device_get_softc(dev); 1340 1341 DPRINTK("xbd_resume: %s\n", xenbus_get_node(dev)); 1342 1343 xbd_free(sc); 1344 xbd_initialize(sc); 1345 return (0); 1346 } 1347 1348 /** 1349 * Callback received when the backend's state changes. 1350 */ 1351 static void 1352 xbd_backend_changed(device_t dev, XenbusState backend_state) 1353 { 1354 struct xbd_softc *sc = device_get_softc(dev); 1355 1356 DPRINTK("backend_state=%d\n", backend_state); 1357 1358 switch (backend_state) { 1359 case XenbusStateUnknown: 1360 case XenbusStateInitialising: 1361 case XenbusStateReconfigured: 1362 case XenbusStateReconfiguring: 1363 case XenbusStateClosed: 1364 break; 1365 1366 case XenbusStateInitWait: 1367 case XenbusStateInitialised: 1368 xbd_initialize(sc); 1369 break; 1370 1371 case XenbusStateConnected: 1372 xbd_initialize(sc); 1373 xbd_connect(sc); 1374 break; 1375 1376 case XenbusStateClosing: 1377 if (sc->xbd_users > 0) 1378 xenbus_dev_error(dev, -EBUSY, 1379 "Device in use; refusing to close"); 1380 else 1381 xbd_closing(dev); 1382 break; 1383 } 1384 } 1385 1386 /*---------------------------- NewBus Registration ---------------------------*/ 1387 static device_method_t xbd_methods[] = { 1388 /* Device interface */ 1389 DEVMETHOD(device_probe, xbd_probe), 1390 DEVMETHOD(device_attach, xbd_attach), 1391 DEVMETHOD(device_detach, xbd_detach), 1392 DEVMETHOD(device_shutdown, bus_generic_shutdown), 1393 DEVMETHOD(device_suspend, xbd_suspend), 1394 DEVMETHOD(device_resume, xbd_resume), 1395 1396 /* Xenbus interface */ 1397 DEVMETHOD(xenbus_otherend_changed, xbd_backend_changed), 1398 1399 { 0, 0 } 1400 }; 1401 1402 static driver_t xbd_driver = { 1403 "xbd", 1404 xbd_methods, 1405 sizeof(struct xbd_softc), 1406 }; 1407 devclass_t xbd_devclass; 1408 1409 DRIVER_MODULE(xbd, xenbusb_front, xbd_driver, xbd_devclass, 0, 0); 1410