2 * XenBSD block device driver
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
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:
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.
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/sysctl.h>
47 #include <machine/bus.h>
49 #include <machine/resource.h>
50 #include <machine/intr_machdep.h>
51 #include <machine/vmparam.h>
52 #include <sys/bus_dma.h>
54 #include <xen/xen-os.h>
55 #include <xen/hypervisor.h>
56 #include <xen/xen_intr.h>
57 #include <xen/gnttab.h>
58 #include <xen/interface/grant_table.h>
59 #include <xen/interface/io/protocols.h>
60 #include <xen/xenbus/xenbusvar.h>
62 #include <machine/_inttypes.h>
64 #include <geom/geom_disk.h>
66 #include <dev/xen/blkfront/block.h>
68 #include "xenbus_if.h"
70 /*--------------------------- Forward Declarations ---------------------------*/
71 static void xbd_closing(device_t);
72 static void xbd_startio(struct xbd_softc *sc);
74 /*---------------------------------- Macros ----------------------------------*/
76 #define DPRINTK(fmt, args...) printf("[XEN] %s:%d: " fmt ".\n", __func__, __LINE__, ##args)
78 #define DPRINTK(fmt, args...)
81 #define XBD_SECTOR_SHFT 9
83 /*---------------------------- Global Static Data ----------------------------*/
84 static MALLOC_DEFINE(M_XENBLOCKFRONT, "xbd", "Xen Block Front driver data");
86 static int xbd_enable_indirect = 1;
87 SYSCTL_NODE(_hw, OID_AUTO, xbd, CTLFLAG_RD, 0, "xbd driver parameters");
88 SYSCTL_INT(_hw_xbd, OID_AUTO, xbd_enable_indirect, CTLFLAG_RDTUN,
89 &xbd_enable_indirect, 0, "Enable xbd indirect segments");
91 /*---------------------------- Command Processing ----------------------------*/
93 xbd_freeze(struct xbd_softc *sc, xbd_flag_t xbd_flag)
95 if (xbd_flag != XBDF_NONE && (sc->xbd_flags & xbd_flag) != 0)
98 sc->xbd_flags |= xbd_flag;
99 sc->xbd_qfrozen_cnt++;
103 xbd_thaw(struct xbd_softc *sc, xbd_flag_t xbd_flag)
105 if (xbd_flag != XBDF_NONE && (sc->xbd_flags & xbd_flag) == 0)
108 if (sc->xbd_qfrozen_cnt == 0)
109 panic("%s: Thaw with flag 0x%x while not frozen.",
112 sc->xbd_flags &= ~xbd_flag;
113 sc->xbd_qfrozen_cnt--;
117 xbd_cm_freeze(struct xbd_softc *sc, struct xbd_command *cm, xbdc_flag_t cm_flag)
119 if ((cm->cm_flags & XBDCF_FROZEN) != 0)
122 cm->cm_flags |= XBDCF_FROZEN|cm_flag;
123 xbd_freeze(sc, XBDF_NONE);
127 xbd_cm_thaw(struct xbd_softc *sc, struct xbd_command *cm)
129 if ((cm->cm_flags & XBDCF_FROZEN) == 0)
132 cm->cm_flags &= ~XBDCF_FROZEN;
133 xbd_thaw(sc, XBDF_NONE);
137 xbd_flush_requests(struct xbd_softc *sc)
141 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->xbd_ring, notify);
144 xen_intr_signal(sc->xen_intr_handle);
148 xbd_free_command(struct xbd_command *cm)
151 KASSERT((cm->cm_flags & XBDCF_Q_MASK) == XBD_Q_NONE,
152 ("Freeing command that is still on queue %d.",
153 cm->cm_flags & XBDCF_Q_MASK));
155 cm->cm_flags = XBDCF_INITIALIZER;
157 cm->cm_complete = NULL;
158 xbd_enqueue_cm(cm, XBD_Q_FREE);
159 xbd_thaw(cm->cm_sc, XBDF_CM_SHORTAGE);
163 xbd_mksegarray(bus_dma_segment_t *segs, int nsegs,
164 grant_ref_t * gref_head, int otherend_id, int readonly,
165 grant_ref_t * sg_ref, struct blkif_request_segment *sg)
167 struct blkif_request_segment *last_block_sg = sg + nsegs;
168 vm_paddr_t buffer_ma;
169 uint64_t fsect, lsect;
172 while (sg < last_block_sg) {
173 KASSERT(segs->ds_addr % (1 << XBD_SECTOR_SHFT) == 0,
174 ("XEN disk driver I/O must be sector aligned"));
175 KASSERT(segs->ds_len % (1 << XBD_SECTOR_SHFT) == 0,
176 ("XEN disk driver I/Os must be a multiple of "
177 "the sector length"));
178 buffer_ma = segs->ds_addr;
179 fsect = (buffer_ma & PAGE_MASK) >> XBD_SECTOR_SHFT;
180 lsect = fsect + (segs->ds_len >> XBD_SECTOR_SHFT) - 1;
182 KASSERT(lsect <= 7, ("XEN disk driver data cannot "
183 "cross a page boundary"));
185 /* install a grant reference. */
186 ref = gnttab_claim_grant_reference(gref_head);
189 * GNTTAB_LIST_END == 0xffffffff, but it is private
192 KASSERT(ref != ~0, ("grant_reference failed"));
194 gnttab_grant_foreign_access_ref(
197 buffer_ma >> PAGE_SHIFT,
201 *sg = (struct blkif_request_segment) {
213 xbd_queue_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
215 struct xbd_softc *sc;
216 struct xbd_command *cm;
223 cm->cm_bp->bio_error = EIO;
225 xbd_free_command(cm);
229 KASSERT(nsegs <= sc->xbd_max_request_segments,
230 ("Too many segments in a blkfront I/O"));
232 if (nsegs <= BLKIF_MAX_SEGMENTS_PER_REQUEST) {
233 blkif_request_t *ring_req;
235 /* Fill out a blkif_request_t structure. */
236 ring_req = (blkif_request_t *)
237 RING_GET_REQUEST(&sc->xbd_ring, sc->xbd_ring.req_prod_pvt);
238 sc->xbd_ring.req_prod_pvt++;
239 ring_req->id = cm->cm_id;
240 ring_req->operation = cm->cm_operation;
241 ring_req->sector_number = cm->cm_sector_number;
242 ring_req->handle = (blkif_vdev_t)(uintptr_t)sc->xbd_disk;
243 ring_req->nr_segments = nsegs;
245 xbd_mksegarray(segs, nsegs, &cm->cm_gref_head,
246 xenbus_get_otherend_id(sc->xbd_dev),
247 cm->cm_operation == BLKIF_OP_WRITE,
248 cm->cm_sg_refs, ring_req->seg);
250 blkif_request_indirect_t *ring_req;
252 /* Fill out a blkif_request_indirect_t structure. */
253 ring_req = (blkif_request_indirect_t *)
254 RING_GET_REQUEST(&sc->xbd_ring, sc->xbd_ring.req_prod_pvt);
255 sc->xbd_ring.req_prod_pvt++;
256 ring_req->id = cm->cm_id;
257 ring_req->operation = BLKIF_OP_INDIRECT;
258 ring_req->indirect_op = cm->cm_operation;
259 ring_req->sector_number = cm->cm_sector_number;
260 ring_req->handle = (blkif_vdev_t)(uintptr_t)sc->xbd_disk;
261 ring_req->nr_segments = nsegs;
263 xbd_mksegarray(segs, nsegs, &cm->cm_gref_head,
264 xenbus_get_otherend_id(sc->xbd_dev),
265 cm->cm_operation == BLKIF_OP_WRITE,
266 cm->cm_sg_refs, cm->cm_indirectionpages);
267 memcpy(ring_req->indirect_grefs, &cm->cm_indirectionrefs,
268 sizeof(grant_ref_t) * sc->xbd_max_request_indirectpages);
271 if (cm->cm_operation == BLKIF_OP_READ)
272 op = BUS_DMASYNC_PREREAD;
273 else if (cm->cm_operation == BLKIF_OP_WRITE)
274 op = BUS_DMASYNC_PREWRITE;
277 bus_dmamap_sync(sc->xbd_io_dmat, cm->cm_map, op);
279 gnttab_free_grant_references(cm->cm_gref_head);
281 xbd_enqueue_cm(cm, XBD_Q_BUSY);
284 * If bus dma had to asynchronously call us back to dispatch
285 * this command, we are no longer executing in the context of
286 * xbd_startio(). Thus we cannot rely on xbd_startio()'s call to
287 * xbd_flush_requests() to publish this command to the backend
288 * along with any other commands that it could batch.
290 if ((cm->cm_flags & XBDCF_ASYNC_MAPPING) != 0)
291 xbd_flush_requests(sc);
297 xbd_queue_request(struct xbd_softc *sc, struct xbd_command *cm)
301 if (cm->cm_bp != NULL)
302 error = bus_dmamap_load_bio(sc->xbd_io_dmat, cm->cm_map,
303 cm->cm_bp, xbd_queue_cb, cm, 0);
305 error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map,
306 cm->cm_data, cm->cm_datalen, xbd_queue_cb, cm, 0);
307 if (error == EINPROGRESS) {
309 * Maintain queuing order by freezing the queue. The next
310 * command may not require as many resources as the command
311 * we just attempted to map, so we can't rely on bus dma
312 * blocking for it too.
314 xbd_cm_freeze(sc, cm, XBDCF_ASYNC_MAPPING);
322 xbd_restart_queue_callback(void *arg)
324 struct xbd_softc *sc = arg;
326 mtx_lock(&sc->xbd_io_lock);
328 xbd_thaw(sc, XBDF_GNT_SHORTAGE);
332 mtx_unlock(&sc->xbd_io_lock);
335 static struct xbd_command *
336 xbd_bio_command(struct xbd_softc *sc)
338 struct xbd_command *cm;
341 if (__predict_false(sc->xbd_state != XBD_STATE_CONNECTED))
344 bp = xbd_dequeue_bio(sc);
348 if ((cm = xbd_dequeue_cm(sc, XBD_Q_FREE)) == NULL) {
349 xbd_freeze(sc, XBDF_CM_SHORTAGE);
350 xbd_requeue_bio(sc, bp);
354 if (gnttab_alloc_grant_references(sc->xbd_max_request_segments,
355 &cm->cm_gref_head) != 0) {
356 gnttab_request_free_callback(&sc->xbd_callback,
357 xbd_restart_queue_callback, sc,
358 sc->xbd_max_request_segments);
359 xbd_freeze(sc, XBDF_GNT_SHORTAGE);
360 xbd_requeue_bio(sc, bp);
361 xbd_enqueue_cm(cm, XBD_Q_FREE);
366 cm->cm_sector_number = (blkif_sector_t)bp->bio_pblkno;
368 switch (bp->bio_cmd) {
370 cm->cm_operation = BLKIF_OP_READ;
373 cm->cm_operation = BLKIF_OP_WRITE;
374 if ((bp->bio_flags & BIO_ORDERED) != 0) {
375 if ((sc->xbd_flags & XBDF_BARRIER) != 0) {
376 cm->cm_operation = BLKIF_OP_WRITE_BARRIER;
379 * Single step this command.
381 cm->cm_flags |= XBDCF_Q_FREEZE;
382 if (xbd_queue_length(sc, XBD_Q_BUSY) != 0) {
384 * Wait for in-flight requests to
387 xbd_freeze(sc, XBDF_WAIT_IDLE);
388 xbd_requeue_cm(cm, XBD_Q_READY);
395 if ((sc->xbd_flags & XBDF_FLUSH) != 0)
396 cm->cm_operation = BLKIF_OP_FLUSH_DISKCACHE;
397 else if ((sc->xbd_flags & XBDF_BARRIER) != 0)
398 cm->cm_operation = BLKIF_OP_WRITE_BARRIER;
400 panic("flush request, but no flush support available");
403 panic("unknown bio command %d", bp->bio_cmd);
410 * Dequeue buffers and place them in the shared communication ring.
411 * Return when no more requests can be accepted or all buffers have
414 * Signal XEN once the ring has been filled out.
417 xbd_startio(struct xbd_softc *sc)
419 struct xbd_command *cm;
420 int error, queued = 0;
422 mtx_assert(&sc->xbd_io_lock, MA_OWNED);
424 if (sc->xbd_state != XBD_STATE_CONNECTED)
427 while (!RING_FULL(&sc->xbd_ring)) {
429 if (sc->xbd_qfrozen_cnt != 0)
432 cm = xbd_dequeue_cm(sc, XBD_Q_READY);
435 cm = xbd_bio_command(sc);
440 if ((cm->cm_flags & XBDCF_Q_FREEZE) != 0) {
442 * Single step command. Future work is
443 * held off until this command completes.
445 xbd_cm_freeze(sc, cm, XBDCF_Q_FREEZE);
448 if ((error = xbd_queue_request(sc, cm)) != 0) {
449 printf("xbd_queue_request returned %d\n", error);
456 xbd_flush_requests(sc);
460 xbd_bio_complete(struct xbd_softc *sc, struct xbd_command *cm)
466 if (__predict_false(cm->cm_status != BLKIF_RSP_OKAY)) {
467 disk_err(bp, "disk error" , -1, 0);
468 printf(" status: %x\n", cm->cm_status);
469 bp->bio_flags |= BIO_ERROR;
472 if (bp->bio_flags & BIO_ERROR)
477 xbd_free_command(cm);
484 struct xbd_softc *sc = xsc;
485 struct xbd_command *cm;
486 blkif_response_t *bret;
490 mtx_lock(&sc->xbd_io_lock);
492 if (__predict_false(sc->xbd_state == XBD_STATE_DISCONNECTED)) {
493 mtx_unlock(&sc->xbd_io_lock);
498 rp = sc->xbd_ring.sring->rsp_prod;
499 rmb(); /* Ensure we see queued responses up to 'rp'. */
501 for (i = sc->xbd_ring.rsp_cons; i != rp;) {
502 bret = RING_GET_RESPONSE(&sc->xbd_ring, i);
503 cm = &sc->xbd_shadow[bret->id];
505 xbd_remove_cm(cm, XBD_Q_BUSY);
506 gnttab_end_foreign_access_references(cm->cm_nseg,
510 if (cm->cm_operation == BLKIF_OP_READ)
511 op = BUS_DMASYNC_POSTREAD;
512 else if (cm->cm_operation == BLKIF_OP_WRITE ||
513 cm->cm_operation == BLKIF_OP_WRITE_BARRIER)
514 op = BUS_DMASYNC_POSTWRITE;
517 bus_dmamap_sync(sc->xbd_io_dmat, cm->cm_map, op);
518 bus_dmamap_unload(sc->xbd_io_dmat, cm->cm_map);
521 * Release any hold this command has on future command
527 * Directly call the i/o complete routine to save an
528 * an indirection in the common case.
530 cm->cm_status = bret->status;
532 xbd_bio_complete(sc, cm);
533 else if (cm->cm_complete != NULL)
536 xbd_free_command(cm);
539 sc->xbd_ring.rsp_cons = i;
541 if (i != sc->xbd_ring.req_prod_pvt) {
543 RING_FINAL_CHECK_FOR_RESPONSES(&sc->xbd_ring, more_to_do);
547 sc->xbd_ring.sring->rsp_event = i + 1;
550 if (xbd_queue_length(sc, XBD_Q_BUSY) == 0)
551 xbd_thaw(sc, XBDF_WAIT_IDLE);
555 if (__predict_false(sc->xbd_state == XBD_STATE_SUSPENDED))
556 wakeup(&sc->xbd_cm_q[XBD_Q_BUSY]);
558 mtx_unlock(&sc->xbd_io_lock);
561 /*------------------------------- Dump Support -------------------------------*/
563 * Quiesce the disk writes for a dump file before allowing the next buffer.
566 xbd_quiesce(struct xbd_softc *sc)
570 // While there are outstanding requests
571 while (xbd_queue_length(sc, XBD_Q_BUSY) != 0) {
572 RING_FINAL_CHECK_FOR_RESPONSES(&sc->xbd_ring, mtd);
574 /* Received request completions, update queue. */
577 if (xbd_queue_length(sc, XBD_Q_BUSY) != 0) {
579 * Still pending requests, wait for the disk i/o
587 /* Kernel dump function for a paravirtualized disk device */
589 xbd_dump_complete(struct xbd_command *cm)
592 xbd_enqueue_cm(cm, XBD_Q_COMPLETE);
596 xbd_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset,
599 struct disk *dp = arg;
600 struct xbd_softc *sc = dp->d_drv1;
601 struct xbd_command *cm;
609 xbd_quiesce(sc); /* All quiet on the western front. */
612 * If this lock is held, then this module is failing, and a
613 * successful kernel dump is highly unlikely anyway.
615 mtx_lock(&sc->xbd_io_lock);
617 /* Split the 64KB block as needed */
618 for (sbp=0; length > 0; sbp++) {
619 cm = xbd_dequeue_cm(sc, XBD_Q_FREE);
621 mtx_unlock(&sc->xbd_io_lock);
622 device_printf(sc->xbd_dev, "dump: no more commands?\n");
626 if (gnttab_alloc_grant_references(sc->xbd_max_request_segments,
627 &cm->cm_gref_head) != 0) {
628 xbd_free_command(cm);
629 mtx_unlock(&sc->xbd_io_lock);
630 device_printf(sc->xbd_dev, "no more grant allocs?\n");
634 chunk = length > sc->xbd_max_request_size ?
635 sc->xbd_max_request_size : length;
636 cm->cm_data = virtual;
637 cm->cm_datalen = chunk;
638 cm->cm_operation = BLKIF_OP_WRITE;
639 cm->cm_sector_number = offset / dp->d_sectorsize;
640 cm->cm_complete = xbd_dump_complete;
642 xbd_enqueue_cm(cm, XBD_Q_READY);
646 virtual = (char *) virtual + chunk;
649 /* Tell DOM0 to do the I/O */
651 mtx_unlock(&sc->xbd_io_lock);
653 /* Poll for the completion. */
654 xbd_quiesce(sc); /* All quite on the eastern front */
656 /* If there were any errors, bail out... */
657 while ((cm = xbd_dequeue_cm(sc, XBD_Q_COMPLETE)) != NULL) {
658 if (cm->cm_status != BLKIF_RSP_OKAY) {
659 device_printf(sc->xbd_dev,
660 "Dump I/O failed at sector %jd\n",
661 cm->cm_sector_number);
664 xbd_free_command(cm);
670 /*----------------------------- Disk Entrypoints -----------------------------*/
672 xbd_open(struct disk *dp)
674 struct xbd_softc *sc = dp->d_drv1;
677 printf("xbd%d: not found", dp->d_unit);
681 sc->xbd_flags |= XBDF_OPEN;
687 xbd_close(struct disk *dp)
689 struct xbd_softc *sc = dp->d_drv1;
693 sc->xbd_flags &= ~XBDF_OPEN;
694 if (--(sc->xbd_users) == 0) {
696 * Check whether we have been instructed to close. We will
697 * have ignored this request initially, as the device was
700 if (xenbus_get_otherend_state(sc->xbd_dev) ==
702 xbd_closing(sc->xbd_dev);
708 xbd_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, struct thread *td)
710 struct xbd_softc *sc = dp->d_drv1;
719 * Read/write routine for a buffer. Finds the proper unit, place it on
720 * the sortq and kick the controller.
723 xbd_strategy(struct bio *bp)
725 struct xbd_softc *sc = bp->bio_disk->d_drv1;
729 bp->bio_error = EINVAL;
730 bp->bio_flags |= BIO_ERROR;
731 bp->bio_resid = bp->bio_bcount;
737 * Place it in the queue of disk activities for this disk
739 mtx_lock(&sc->xbd_io_lock);
741 xbd_enqueue_bio(sc, bp);
744 mtx_unlock(&sc->xbd_io_lock);
748 /*------------------------------ Ring Management -----------------------------*/
750 xbd_alloc_ring(struct xbd_softc *sc)
752 blkif_sring_t *sring;
753 uintptr_t sring_page_addr;
757 sring = malloc(sc->xbd_ring_pages * PAGE_SIZE, M_XENBLOCKFRONT,
760 xenbus_dev_fatal(sc->xbd_dev, ENOMEM, "allocating shared ring");
763 SHARED_RING_INIT(sring);
764 FRONT_RING_INIT(&sc->xbd_ring, sring, sc->xbd_ring_pages * PAGE_SIZE);
766 for (i = 0, sring_page_addr = (uintptr_t)sring;
767 i < sc->xbd_ring_pages;
768 i++, sring_page_addr += PAGE_SIZE) {
770 error = xenbus_grant_ring(sc->xbd_dev,
771 (vtophys(sring_page_addr) >> PAGE_SHIFT),
772 &sc->xbd_ring_ref[i]);
774 xenbus_dev_fatal(sc->xbd_dev, error,
775 "granting ring_ref(%d)", i);
779 if (sc->xbd_ring_pages == 1) {
780 error = xs_printf(XST_NIL, xenbus_get_node(sc->xbd_dev),
781 "ring-ref", "%u", sc->xbd_ring_ref[0]);
783 xenbus_dev_fatal(sc->xbd_dev, error,
784 "writing %s/ring-ref",
785 xenbus_get_node(sc->xbd_dev));
789 for (i = 0; i < sc->xbd_ring_pages; i++) {
790 char ring_ref_name[]= "ring_refXX";
792 snprintf(ring_ref_name, sizeof(ring_ref_name),
794 error = xs_printf(XST_NIL, xenbus_get_node(sc->xbd_dev),
795 ring_ref_name, "%u", sc->xbd_ring_ref[i]);
797 xenbus_dev_fatal(sc->xbd_dev, error,
799 xenbus_get_node(sc->xbd_dev),
806 error = xen_intr_alloc_and_bind_local_port(sc->xbd_dev,
807 xenbus_get_otherend_id(sc->xbd_dev), NULL, xbd_int, sc,
808 INTR_TYPE_BIO | INTR_MPSAFE, &sc->xen_intr_handle);
810 xenbus_dev_fatal(sc->xbd_dev, error,
811 "xen_intr_alloc_and_bind_local_port failed");
819 xbd_free_ring(struct xbd_softc *sc)
823 if (sc->xbd_ring.sring == NULL)
826 for (i = 0; i < sc->xbd_ring_pages; i++) {
827 if (sc->xbd_ring_ref[i] != GRANT_REF_INVALID) {
828 gnttab_end_foreign_access_ref(sc->xbd_ring_ref[i]);
829 sc->xbd_ring_ref[i] = GRANT_REF_INVALID;
832 free(sc->xbd_ring.sring, M_XENBLOCKFRONT);
833 sc->xbd_ring.sring = NULL;
836 /*-------------------------- Initialization/Teardown -------------------------*/
838 xbd_feature_string(struct xbd_softc *sc, char *features, size_t len)
843 sbuf_new(&sb, features, len, SBUF_FIXEDLEN);
846 if ((sc->xbd_flags & XBDF_FLUSH) != 0) {
847 sbuf_printf(&sb, "flush");
851 if ((sc->xbd_flags & XBDF_BARRIER) != 0) {
852 if (feature_cnt != 0)
853 sbuf_printf(&sb, ", ");
854 sbuf_printf(&sb, "write_barrier");
858 if ((sc->xbd_flags & XBDF_DISCARD) != 0) {
859 if (feature_cnt != 0)
860 sbuf_printf(&sb, ", ");
861 sbuf_printf(&sb, "discard");
865 if ((sc->xbd_flags & XBDF_PERSISTENT) != 0) {
866 if (feature_cnt != 0)
867 sbuf_printf(&sb, ", ");
868 sbuf_printf(&sb, "persistent_grants");
872 (void) sbuf_finish(&sb);
873 return (sbuf_len(&sb));
877 xbd_sysctl_features(SYSCTL_HANDLER_ARGS)
880 struct xbd_softc *sc = arg1;
884 error = sysctl_wire_old_buffer(req, 0);
888 len = xbd_feature_string(sc, features, sizeof(features));
890 /* len is -1 on error, which will make the SYSCTL_OUT a no-op. */
891 return (SYSCTL_OUT(req, features, len + 1/*NUL*/));
895 xbd_setup_sysctl(struct xbd_softc *xbd)
897 struct sysctl_ctx_list *sysctl_ctx = NULL;
898 struct sysctl_oid *sysctl_tree = NULL;
899 struct sysctl_oid_list *children;
901 sysctl_ctx = device_get_sysctl_ctx(xbd->xbd_dev);
902 if (sysctl_ctx == NULL)
905 sysctl_tree = device_get_sysctl_tree(xbd->xbd_dev);
906 if (sysctl_tree == NULL)
909 children = SYSCTL_CHILDREN(sysctl_tree);
910 SYSCTL_ADD_UINT(sysctl_ctx, children, OID_AUTO,
911 "max_requests", CTLFLAG_RD, &xbd->xbd_max_requests, -1,
912 "maximum outstanding requests (negotiated)");
914 SYSCTL_ADD_UINT(sysctl_ctx, children, OID_AUTO,
915 "max_request_segments", CTLFLAG_RD,
916 &xbd->xbd_max_request_segments, 0,
917 "maximum number of pages per requests (negotiated)");
919 SYSCTL_ADD_UINT(sysctl_ctx, children, OID_AUTO,
920 "max_request_size", CTLFLAG_RD, &xbd->xbd_max_request_size, 0,
921 "maximum size in bytes of a request (negotiated)");
923 SYSCTL_ADD_UINT(sysctl_ctx, children, OID_AUTO,
924 "ring_pages", CTLFLAG_RD, &xbd->xbd_ring_pages, 0,
925 "communication channel pages (negotiated)");
927 SYSCTL_ADD_PROC(sysctl_ctx, children, OID_AUTO,
928 "features", CTLTYPE_STRING|CTLFLAG_RD, xbd, 0,
929 xbd_sysctl_features, "A", "protocol features (negotiated)");
933 * Translate Linux major/minor to an appropriate name and unit
934 * number. For HVM guests, this allows us to use the same drive names
935 * with blkfront as the emulated drives, easing transition slightly.
938 xbd_vdevice_to_unit(uint32_t vdevice, int *unit, const char **name)
940 static struct vdev_info {
946 {3, 6, 0, "ada"}, /* ide0 */
947 {22, 6, 2, "ada"}, /* ide1 */
948 {33, 6, 4, "ada"}, /* ide2 */
949 {34, 6, 6, "ada"}, /* ide3 */
950 {56, 6, 8, "ada"}, /* ide4 */
951 {57, 6, 10, "ada"}, /* ide5 */
952 {88, 6, 12, "ada"}, /* ide6 */
953 {89, 6, 14, "ada"}, /* ide7 */
954 {90, 6, 16, "ada"}, /* ide8 */
955 {91, 6, 18, "ada"}, /* ide9 */
957 {8, 4, 0, "da"}, /* scsi disk0 */
958 {65, 4, 16, "da"}, /* scsi disk1 */
959 {66, 4, 32, "da"}, /* scsi disk2 */
960 {67, 4, 48, "da"}, /* scsi disk3 */
961 {68, 4, 64, "da"}, /* scsi disk4 */
962 {69, 4, 80, "da"}, /* scsi disk5 */
963 {70, 4, 96, "da"}, /* scsi disk6 */
964 {71, 4, 112, "da"}, /* scsi disk7 */
965 {128, 4, 128, "da"}, /* scsi disk8 */
966 {129, 4, 144, "da"}, /* scsi disk9 */
967 {130, 4, 160, "da"}, /* scsi disk10 */
968 {131, 4, 176, "da"}, /* scsi disk11 */
969 {132, 4, 192, "da"}, /* scsi disk12 */
970 {133, 4, 208, "da"}, /* scsi disk13 */
971 {134, 4, 224, "da"}, /* scsi disk14 */
972 {135, 4, 240, "da"}, /* scsi disk15 */
974 {202, 4, 0, "xbd"}, /* xbd */
978 int major = vdevice >> 8;
979 int minor = vdevice & 0xff;
982 if (vdevice & (1 << 28)) {
983 *unit = (vdevice & ((1 << 28) - 1)) >> 8;
988 for (i = 0; info[i].major; i++) {
989 if (info[i].major == major) {
990 *unit = info[i].base + (minor >> info[i].shift);
991 *name = info[i].name;
1001 xbd_instance_create(struct xbd_softc *sc, blkif_sector_t sectors,
1002 int vdevice, uint16_t vdisk_info, unsigned long sector_size,
1003 unsigned long phys_sector_size)
1006 int unit, error = 0;
1009 xbd_vdevice_to_unit(vdevice, &unit, &name);
1011 sc->xbd_unit = unit;
1013 if (strcmp(name, "xbd") != 0)
1014 device_printf(sc->xbd_dev, "attaching as %s%d\n", name, unit);
1016 if (xbd_feature_string(sc, features, sizeof(features)) > 0) {
1017 device_printf(sc->xbd_dev, "features: %s\n",
1021 sc->xbd_disk = disk_alloc();
1022 sc->xbd_disk->d_unit = sc->xbd_unit;
1023 sc->xbd_disk->d_open = xbd_open;
1024 sc->xbd_disk->d_close = xbd_close;
1025 sc->xbd_disk->d_ioctl = xbd_ioctl;
1026 sc->xbd_disk->d_strategy = xbd_strategy;
1027 sc->xbd_disk->d_dump = xbd_dump;
1028 sc->xbd_disk->d_name = name;
1029 sc->xbd_disk->d_drv1 = sc;
1030 sc->xbd_disk->d_sectorsize = sector_size;
1031 sc->xbd_disk->d_stripesize = phys_sector_size;
1032 sc->xbd_disk->d_stripeoffset = 0;
1034 sc->xbd_disk->d_mediasize = sectors * sector_size;
1035 sc->xbd_disk->d_maxsize = sc->xbd_max_request_size;
1036 sc->xbd_disk->d_flags = DISKFLAG_UNMAPPED_BIO;
1037 if ((sc->xbd_flags & (XBDF_FLUSH|XBDF_BARRIER)) != 0) {
1038 sc->xbd_disk->d_flags |= DISKFLAG_CANFLUSHCACHE;
1039 device_printf(sc->xbd_dev,
1040 "synchronize cache commands enabled.\n");
1042 disk_create(sc->xbd_disk, DISK_VERSION);
1048 xbd_free(struct xbd_softc *sc)
1052 /* Prevent new requests being issued until we fix things up. */
1053 mtx_lock(&sc->xbd_io_lock);
1054 sc->xbd_state = XBD_STATE_DISCONNECTED;
1055 mtx_unlock(&sc->xbd_io_lock);
1057 /* Free resources associated with old device channel. */
1059 if (sc->xbd_shadow) {
1061 for (i = 0; i < sc->xbd_max_requests; i++) {
1062 struct xbd_command *cm;
1064 cm = &sc->xbd_shadow[i];
1065 if (cm->cm_sg_refs != NULL) {
1066 free(cm->cm_sg_refs, M_XENBLOCKFRONT);
1067 cm->cm_sg_refs = NULL;
1070 if (cm->cm_indirectionpages != NULL) {
1071 gnttab_end_foreign_access_references(
1072 sc->xbd_max_request_indirectpages,
1073 &cm->cm_indirectionrefs[0]);
1074 contigfree(cm->cm_indirectionpages, PAGE_SIZE *
1075 sc->xbd_max_request_indirectpages,
1077 cm->cm_indirectionpages = NULL;
1080 bus_dmamap_destroy(sc->xbd_io_dmat, cm->cm_map);
1082 free(sc->xbd_shadow, M_XENBLOCKFRONT);
1083 sc->xbd_shadow = NULL;
1085 bus_dma_tag_destroy(sc->xbd_io_dmat);
1087 xbd_initq_cm(sc, XBD_Q_FREE);
1088 xbd_initq_cm(sc, XBD_Q_READY);
1089 xbd_initq_cm(sc, XBD_Q_COMPLETE);
1092 xen_intr_unbind(&sc->xen_intr_handle);
1096 /*--------------------------- State Change Handlers --------------------------*/
1098 xbd_initialize(struct xbd_softc *sc)
1100 const char *otherend_path;
1101 const char *node_path;
1102 uint32_t max_ring_page_order;
1105 if (xenbus_get_state(sc->xbd_dev) != XenbusStateInitialising) {
1106 /* Initialization has already been performed. */
1111 * Protocol defaults valid even if negotiation for a
1114 max_ring_page_order = 0;
1115 sc->xbd_ring_pages = 1;
1118 * Protocol negotiation.
1120 * \note xs_gather() returns on the first encountered error, so
1121 * we must use independent calls in order to guarantee
1122 * we don't miss information in a sparsly populated back-end
1125 * \note xs_scanf() does not update variables for unmatched
1128 otherend_path = xenbus_get_otherend_path(sc->xbd_dev);
1129 node_path = xenbus_get_node(sc->xbd_dev);
1131 /* Support both backend schemes for relaying ring page limits. */
1132 (void)xs_scanf(XST_NIL, otherend_path,
1133 "max-ring-page-order", NULL, "%" PRIu32,
1134 &max_ring_page_order);
1135 sc->xbd_ring_pages = 1 << max_ring_page_order;
1136 (void)xs_scanf(XST_NIL, otherend_path,
1137 "max-ring-pages", NULL, "%" PRIu32,
1138 &sc->xbd_ring_pages);
1139 if (sc->xbd_ring_pages < 1)
1140 sc->xbd_ring_pages = 1;
1142 if (sc->xbd_ring_pages > XBD_MAX_RING_PAGES) {
1143 device_printf(sc->xbd_dev,
1144 "Back-end specified ring-pages of %u "
1145 "limited to front-end limit of %u.\n",
1146 sc->xbd_ring_pages, XBD_MAX_RING_PAGES);
1147 sc->xbd_ring_pages = XBD_MAX_RING_PAGES;
1150 if (powerof2(sc->xbd_ring_pages) == 0) {
1151 uint32_t new_page_limit;
1153 new_page_limit = 0x01 << (fls(sc->xbd_ring_pages) - 1);
1154 device_printf(sc->xbd_dev,
1155 "Back-end specified ring-pages of %u "
1156 "is not a power of 2. Limited to %u.\n",
1157 sc->xbd_ring_pages, new_page_limit);
1158 sc->xbd_ring_pages = new_page_limit;
1161 sc->xbd_max_requests =
1162 BLKIF_MAX_RING_REQUESTS(sc->xbd_ring_pages * PAGE_SIZE);
1163 if (sc->xbd_max_requests > XBD_MAX_REQUESTS) {
1164 device_printf(sc->xbd_dev,
1165 "Back-end specified max_requests of %u "
1166 "limited to front-end limit of %zu.\n",
1167 sc->xbd_max_requests, XBD_MAX_REQUESTS);
1168 sc->xbd_max_requests = XBD_MAX_REQUESTS;
1171 if (xbd_alloc_ring(sc) != 0)
1174 /* Support both backend schemes for relaying ring page limits. */
1175 if (sc->xbd_ring_pages > 1) {
1176 error = xs_printf(XST_NIL, node_path,
1177 "num-ring-pages","%u",
1178 sc->xbd_ring_pages);
1180 xenbus_dev_fatal(sc->xbd_dev, error,
1181 "writing %s/num-ring-pages",
1186 error = xs_printf(XST_NIL, node_path,
1187 "ring-page-order", "%u",
1188 fls(sc->xbd_ring_pages) - 1);
1190 xenbus_dev_fatal(sc->xbd_dev, error,
1191 "writing %s/ring-page-order",
1197 error = xs_printf(XST_NIL, node_path, "event-channel",
1198 "%u", xen_intr_port(sc->xen_intr_handle));
1200 xenbus_dev_fatal(sc->xbd_dev, error,
1201 "writing %s/event-channel",
1206 error = xs_printf(XST_NIL, node_path, "protocol",
1207 "%s", XEN_IO_PROTO_ABI_NATIVE);
1209 xenbus_dev_fatal(sc->xbd_dev, error,
1210 "writing %s/protocol",
1215 xenbus_set_state(sc->xbd_dev, XenbusStateInitialised);
1219 * Invoked when the backend is finally 'ready' (and has published
1220 * the details about the physical device - #sectors, size, etc).
1223 xbd_connect(struct xbd_softc *sc)
1225 device_t dev = sc->xbd_dev;
1226 unsigned long sectors, sector_size, phys_sector_size;
1228 int err, feature_barrier, feature_flush;
1231 if (sc->xbd_state == XBD_STATE_CONNECTED ||
1232 sc->xbd_state == XBD_STATE_SUSPENDED)
1235 DPRINTK("blkfront.c:connect:%s.\n", xenbus_get_otherend_path(dev));
1237 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev),
1238 "sectors", "%lu", §ors,
1239 "info", "%u", &binfo,
1240 "sector-size", "%lu", §or_size,
1243 xenbus_dev_fatal(dev, err,
1244 "reading backend fields at %s",
1245 xenbus_get_otherend_path(dev));
1248 if ((sectors == 0) || (sector_size == 0)) {
1249 xenbus_dev_fatal(dev, 0,
1250 "invalid parameters from %s:"
1251 " sectors = %lu, sector_size = %lu",
1252 xenbus_get_otherend_path(dev),
1253 sectors, sector_size);
1256 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev),
1257 "physical-sector-size", "%lu", &phys_sector_size,
1259 if (err || phys_sector_size <= sector_size)
1260 phys_sector_size = 0;
1261 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev),
1262 "feature-barrier", "%d", &feature_barrier,
1264 if (err == 0 && feature_barrier != 0)
1265 sc->xbd_flags |= XBDF_BARRIER;
1267 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev),
1268 "feature-flush-cache", "%d", &feature_flush,
1270 if (err == 0 && feature_flush != 0)
1271 sc->xbd_flags |= XBDF_FLUSH;
1273 err = xs_gather(XST_NIL, xenbus_get_otherend_path(dev),
1274 "feature-max-indirect-segments", "%" PRIu32,
1275 &sc->xbd_max_request_segments, NULL);
1276 if ((err != 0) || (xbd_enable_indirect == 0))
1277 sc->xbd_max_request_segments = 0;
1278 if (sc->xbd_max_request_segments > XBD_MAX_INDIRECT_SEGMENTS)
1279 sc->xbd_max_request_segments = XBD_MAX_INDIRECT_SEGMENTS;
1280 if (sc->xbd_max_request_segments > XBD_SIZE_TO_SEGS(MAXPHYS))
1281 sc->xbd_max_request_segments = XBD_SIZE_TO_SEGS(MAXPHYS);
1282 sc->xbd_max_request_indirectpages =
1283 XBD_INDIRECT_SEGS_TO_PAGES(sc->xbd_max_request_segments);
1284 if (sc->xbd_max_request_segments < BLKIF_MAX_SEGMENTS_PER_REQUEST)
1285 sc->xbd_max_request_segments = BLKIF_MAX_SEGMENTS_PER_REQUEST;
1286 sc->xbd_max_request_size =
1287 XBD_SEGS_TO_SIZE(sc->xbd_max_request_segments);
1289 /* Allocate datastructures based on negotiated values. */
1290 err = bus_dma_tag_create(
1291 bus_get_dma_tag(sc->xbd_dev), /* parent */
1292 512, PAGE_SIZE, /* algnmnt, boundary */
1293 BUS_SPACE_MAXADDR, /* lowaddr */
1294 BUS_SPACE_MAXADDR, /* highaddr */
1295 NULL, NULL, /* filter, filterarg */
1296 sc->xbd_max_request_size,
1297 sc->xbd_max_request_segments,
1298 PAGE_SIZE, /* maxsegsize */
1299 BUS_DMA_ALLOCNOW, /* flags */
1300 busdma_lock_mutex, /* lockfunc */
1301 &sc->xbd_io_lock, /* lockarg */
1304 xenbus_dev_fatal(sc->xbd_dev, err,
1305 "Cannot allocate parent DMA tag\n");
1309 /* Per-transaction data allocation. */
1310 sc->xbd_shadow = malloc(sizeof(*sc->xbd_shadow) * sc->xbd_max_requests,
1311 M_XENBLOCKFRONT, M_NOWAIT|M_ZERO);
1312 if (sc->xbd_shadow == NULL) {
1313 bus_dma_tag_destroy(sc->xbd_io_dmat);
1314 xenbus_dev_fatal(sc->xbd_dev, ENOMEM,
1315 "Cannot allocate request structures\n");
1319 for (i = 0; i < sc->xbd_max_requests; i++) {
1320 struct xbd_command *cm;
1321 void * indirectpages;
1323 cm = &sc->xbd_shadow[i];
1324 cm->cm_sg_refs = malloc(
1325 sizeof(grant_ref_t) * sc->xbd_max_request_segments,
1326 M_XENBLOCKFRONT, M_NOWAIT);
1327 if (cm->cm_sg_refs == NULL)
1330 cm->cm_flags = XBDCF_INITIALIZER;
1332 if (bus_dmamap_create(sc->xbd_io_dmat, 0, &cm->cm_map) != 0)
1334 if (sc->xbd_max_request_indirectpages > 0) {
1335 indirectpages = contigmalloc(
1336 PAGE_SIZE * sc->xbd_max_request_indirectpages,
1337 M_XENBLOCKFRONT, M_ZERO, 0, ~0, PAGE_SIZE, 0);
1339 indirectpages = NULL;
1341 for (j = 0; j < sc->xbd_max_request_indirectpages; j++) {
1342 if (gnttab_grant_foreign_access(
1343 xenbus_get_otherend_id(sc->xbd_dev),
1344 (vtophys(indirectpages) >> PAGE_SHIFT) + j,
1345 1 /* grant read-only access */,
1346 &cm->cm_indirectionrefs[j]))
1349 if (j < sc->xbd_max_request_indirectpages)
1351 cm->cm_indirectionpages = indirectpages;
1352 xbd_free_command(cm);
1355 if (sc->xbd_disk == NULL) {
1356 device_printf(dev, "%juMB <%s> at %s",
1357 (uintmax_t) sectors / (1048576 / sector_size),
1358 device_get_desc(dev),
1359 xenbus_get_node(dev));
1360 bus_print_child_footer(device_get_parent(dev), dev);
1362 xbd_instance_create(sc, sectors, sc->xbd_vdevice, binfo,
1363 sector_size, phys_sector_size);
1366 (void)xenbus_set_state(dev, XenbusStateConnected);
1368 /* Kick pending requests. */
1369 mtx_lock(&sc->xbd_io_lock);
1370 sc->xbd_state = XBD_STATE_CONNECTED;
1372 sc->xbd_flags |= XBDF_READY;
1373 mtx_unlock(&sc->xbd_io_lock);
1377 * Handle the change of state of the backend to Closing. We must delete our
1378 * device-layer structures now, to ensure that writes are flushed through to
1379 * the backend. Once this is done, we can switch to Closed in
1383 xbd_closing(device_t dev)
1385 struct xbd_softc *sc = device_get_softc(dev);
1387 xenbus_set_state(dev, XenbusStateClosing);
1389 DPRINTK("xbd_closing: %s removed\n", xenbus_get_node(dev));
1391 if (sc->xbd_disk != NULL) {
1392 disk_destroy(sc->xbd_disk);
1393 sc->xbd_disk = NULL;
1396 xenbus_set_state(dev, XenbusStateClosed);
1399 /*---------------------------- NewBus Entrypoints ----------------------------*/
1401 xbd_probe(device_t dev)
1403 if (strcmp(xenbus_get_type(dev), "vbd") != 0)
1406 if (xen_hvm_domain() && xen_disable_pv_disks != 0)
1409 if (xen_hvm_domain()) {
1414 * When running in an HVM domain, IDE disk emulation is
1415 * disabled early in boot so that native drivers will
1416 * not see emulated hardware. However, CDROM device
1417 * emulation cannot be disabled.
1419 * Through use of FreeBSD's vm_guest and xen_hvm_domain()
1420 * APIs, we could modify the native CDROM driver to fail its
1421 * probe when running under Xen. Unfortunatlely, the PV
1422 * CDROM support in XenServer (up through at least version
1423 * 6.2) isn't functional, so we instead rely on the emulated
1424 * CDROM instance, and fail to attach the PV one here in
1425 * the blkfront driver.
1427 error = xs_read(XST_NIL, xenbus_get_node(dev),
1428 "device-type", NULL, (void **) &type);
1432 if (strncmp(type, "cdrom", 5) == 0) {
1433 free(type, M_XENSTORE);
1436 free(type, M_XENSTORE);
1439 device_set_desc(dev, "Virtual Block Device");
1445 * Setup supplies the backend dir, virtual device. We place an event
1446 * channel and shared frame entries. We watch backend to wait if it's
1450 xbd_attach(device_t dev)
1452 struct xbd_softc *sc;
1459 /* FIXME: Use dynamic device id if this is not set. */
1460 error = xs_scanf(XST_NIL, xenbus_get_node(dev),
1461 "virtual-device", NULL, "%" PRIu32, &vdevice);
1463 error = xs_scanf(XST_NIL, xenbus_get_node(dev),
1464 "virtual-device-ext", NULL, "%" PRIu32, &vdevice);
1466 xenbus_dev_fatal(dev, error, "reading virtual-device");
1467 device_printf(dev, "Couldn't determine virtual device.\n");
1471 xbd_vdevice_to_unit(vdevice, &unit, &name);
1472 if (!strcmp(name, "xbd"))
1473 device_set_unit(dev, unit);
1475 sc = device_get_softc(dev);
1476 mtx_init(&sc->xbd_io_lock, "blkfront i/o lock", NULL, MTX_DEF);
1478 for (i = 0; i < XBD_MAX_RING_PAGES; i++)
1479 sc->xbd_ring_ref[i] = GRANT_REF_INVALID;
1482 sc->xbd_vdevice = vdevice;
1483 sc->xbd_state = XBD_STATE_DISCONNECTED;
1485 xbd_setup_sysctl(sc);
1487 /* Wait for backend device to publish its protocol capabilities. */
1488 xenbus_set_state(dev, XenbusStateInitialising);
1494 xbd_detach(device_t dev)
1496 struct xbd_softc *sc = device_get_softc(dev);
1498 DPRINTK("%s: %s removed\n", __func__, xenbus_get_node(dev));
1501 mtx_destroy(&sc->xbd_io_lock);
1507 xbd_suspend(device_t dev)
1509 struct xbd_softc *sc = device_get_softc(dev);
1513 /* Prevent new requests being issued until we fix things up. */
1514 mtx_lock(&sc->xbd_io_lock);
1515 saved_state = sc->xbd_state;
1516 sc->xbd_state = XBD_STATE_SUSPENDED;
1518 /* Wait for outstanding I/O to drain. */
1520 while (xbd_queue_length(sc, XBD_Q_BUSY) != 0) {
1521 if (msleep(&sc->xbd_cm_q[XBD_Q_BUSY], &sc->xbd_io_lock,
1522 PRIBIO, "blkf_susp", 30 * hz) == EWOULDBLOCK) {
1527 mtx_unlock(&sc->xbd_io_lock);
1530 sc->xbd_state = saved_state;
1536 xbd_resume(device_t dev)
1538 struct xbd_softc *sc = device_get_softc(dev);
1540 if (xen_suspend_cancelled) {
1541 sc->xbd_state = XBD_STATE_CONNECTED;
1545 DPRINTK("xbd_resume: %s\n", xenbus_get_node(dev));
1553 * Callback received when the backend's state changes.
1556 xbd_backend_changed(device_t dev, XenbusState backend_state)
1558 struct xbd_softc *sc = device_get_softc(dev);
1560 DPRINTK("backend_state=%d\n", backend_state);
1562 switch (backend_state) {
1563 case XenbusStateUnknown:
1564 case XenbusStateInitialising:
1565 case XenbusStateReconfigured:
1566 case XenbusStateReconfiguring:
1567 case XenbusStateClosed:
1570 case XenbusStateInitWait:
1571 case XenbusStateInitialised:
1575 case XenbusStateConnected:
1580 case XenbusStateClosing:
1581 if (sc->xbd_users > 0) {
1582 device_printf(dev, "detaching with pending users\n");
1583 KASSERT(sc->xbd_disk != NULL,
1584 ("NULL disk with pending users\n"));
1585 disk_gone(sc->xbd_disk);
1593 /*---------------------------- NewBus Registration ---------------------------*/
1594 static device_method_t xbd_methods[] = {
1595 /* Device interface */
1596 DEVMETHOD(device_probe, xbd_probe),
1597 DEVMETHOD(device_attach, xbd_attach),
1598 DEVMETHOD(device_detach, xbd_detach),
1599 DEVMETHOD(device_shutdown, bus_generic_shutdown),
1600 DEVMETHOD(device_suspend, xbd_suspend),
1601 DEVMETHOD(device_resume, xbd_resume),
1603 /* Xenbus interface */
1604 DEVMETHOD(xenbus_otherend_changed, xbd_backend_changed),
1609 static driver_t xbd_driver = {
1612 sizeof(struct xbd_softc),
1614 devclass_t xbd_devclass;
1616 DRIVER_MODULE(xbd, xenbusb_front, xbd_driver, xbd_devclass, 0, 0);