1/* $NetBSD$ */
2/******************************************************************************
3 * Talks to Xen Store to figure out what devices we have.
4 *
5 * Copyright (C) 2005 Rusty Russell, IBM Corporation
6 * Copyright (C) 2005 Mike Wray, Hewlett-Packard
7 * Copyright (C) 2005 XenSource Ltd
8 *
9 * This file may be distributed separately from the Linux kernel, or
10 * incorporated into other software packages, subject to the following license:
11 *
12 * Permission is hereby granted, free of charge, to any person obtaining a copy
13 * of this source file (the "Software"), to deal in the Software without
14 * restriction, including without limitation the rights to use, copy, modify,
15 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
16 * and to permit persons to whom the Software is furnished to do so, subject to
17 * the following conditions:
18 *
19 * The above copyright notice and this permission notice shall be included in
20 * all copies or substantial portions of the Software.
21 *
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 DEALINGS
28 * IN THE SOFTWARE.
29 */
30
31#include <sys/cdefs.h>
32__KERNEL_RCSID(0, "$NetBSD$");
33
34#if 0
35#define DPRINTK(fmt, args...) \
36    printf("xenbus_probe (%s:%d) " fmt ".\n", __func__, __LINE__, ##args)
37#else
38#define DPRINTK(fmt, args...) ((void)0)
39#endif
40
41#include <sys/types.h>
42#include <sys/null.h>
43#include <sys/errno.h>
44#include <sys/malloc.h>
45#include <sys/systm.h>
46#include <sys/param.h>
47#include <sys/kthread.h>
48#include <uvm/uvm.h>
49
50#include <xen/xen.h>	/* for xendomain_is_dom0() */
51#include <xen/hypervisor.h>
52#include <xen/xenbus.h>
53#include <xen/evtchn.h>
54#include <xen/shutdown_xenbus.h>
55
56#include "xenbus_comms.h"
57
58extern struct semaphore xenwatch_mutex;
59
60#define streq(a, b) (strcmp((a), (b)) == 0)
61
62static int  xenbus_match(device_t, cfdata_t, void *);
63static void xenbus_attach(device_t, device_t, void *);
64static int  xenbus_print(void *, const char *);
65
66/* power management, for save/restore */
67static bool xenbus_suspend(device_t, const pmf_qual_t *);
68static bool xenbus_resume(device_t, const pmf_qual_t *);
69
70/* routines gathering device information from XenStore */
71static int  read_otherend_details(struct xenbus_device *,
72		const char *, const char *);
73static int  read_backend_details (struct xenbus_device *);
74static int  read_frontend_details(struct xenbus_device *);
75static void free_otherend_details(struct xenbus_device *);
76
77static int  watch_otherend     (struct xenbus_device *);
78static void free_otherend_watch(struct xenbus_device *);
79
80static void xenbus_probe_init(void *);
81
82static struct xenbus_device *xenbus_lookup_device_path(const char *);
83
84CFATTACH_DECL_NEW(xenbus, 0, xenbus_match, xenbus_attach,
85    NULL, NULL);
86
87device_t xenbus_dev;
88
89SLIST_HEAD(, xenbus_device) xenbus_device_list;
90SLIST_HEAD(, xenbus_backend_driver) xenbus_backend_driver_list =
91	SLIST_HEAD_INITIALIZER(xenbus_backend_driver);
92
93int
94xenbus_match(device_t parent, cfdata_t match, void *aux)
95{
96	struct xenbus_attach_args *xa = (struct xenbus_attach_args *)aux;
97
98	if (strcmp(xa->xa_device, "xenbus") == 0)
99		return 1;
100	return 0;
101}
102
103static void
104xenbus_attach(device_t parent, device_t self, void *aux)
105{
106	int err;
107
108	aprint_normal(": Xen Virtual Bus Interface\n");
109	xenbus_dev = self;
110	config_pending_incr();
111
112	err = kthread_create(PRI_NONE, 0, NULL, xenbus_probe_init, NULL,
113	    NULL, "xenbus_probe");
114	if (err)
115		aprint_error_dev(xenbus_dev,
116				"kthread_create(xenbus_probe): %d\n", err);
117
118	if (!pmf_device_register(self, xenbus_suspend, xenbus_resume))
119		aprint_error_dev(self, "couldn't establish power handler\n");
120}
121
122static bool
123xenbus_suspend(device_t dev, const pmf_qual_t *qual)
124{
125	xs_suspend();
126	xb_suspend_comms(dev);
127
128	return true;
129}
130
131static bool
132xenbus_resume(device_t dev, const pmf_qual_t *qual)
133{
134	xb_init_comms(dev);
135	xs_resume();
136
137	return true;
138}
139
140/*
141 * Suspend a xenbus device
142 */
143bool
144xenbus_device_suspend(struct xenbus_device *dev) {
145
146	free_otherend_details(dev);
147	return true;
148}
149
150/*
151 * Resume a xenbus device
152 */
153bool
154xenbus_device_resume(struct xenbus_device *dev) {
155
156	if (dev->xbusd_type == XENBUS_FRONTEND_DEVICE) {
157		read_backend_details(dev);
158	}
159
160	return true;
161}
162
163void
164xenbus_backend_register(struct xenbus_backend_driver *xbakd)
165{
166	SLIST_INSERT_HEAD(&xenbus_backend_driver_list, xbakd, xbakd_entries);
167}
168
169static int
170read_otherend_details(struct xenbus_device *xendev,
171				 const char *id_node, const char *path_node)
172{
173	int err;
174	char *val, *ep;
175
176	err = xenbus_read(NULL, xendev->xbusd_path, id_node, NULL, &val);
177	if (err) {
178		printf("reading other end details %s from %s\n",
179		    id_node, xendev->xbusd_path);
180		xenbus_dev_fatal(xendev, err,
181				 "reading other end details %s from %s",
182				 id_node, xendev->xbusd_path);
183		return err;
184	}
185	xendev->xbusd_otherend_id = strtoul(val, &ep, 10);
186	if (val[0] == '\0' || *ep != '\0') {
187		printf("reading other end details %s from %s: %s is not a number\n", id_node, xendev->xbusd_path, val);
188		xenbus_dev_fatal(xendev, err,
189		    "reading other end details %s from %s: %s is not a number",
190		    id_node, xendev->xbusd_path, val);
191		free(val, M_DEVBUF);
192		return EFTYPE;
193	}
194	free(val, M_DEVBUF);
195	err = xenbus_read(NULL, xendev->xbusd_path, path_node, NULL, &val);
196	if (err) {
197		printf("reading other end details %s from %s (%d)\n",
198		    path_node, xendev->xbusd_path, err);
199		xenbus_dev_fatal(xendev, err,
200				 "reading other end details %s from %s",
201				 path_node, xendev->xbusd_path);
202		return err;
203	}
204	DPRINTK("read_otherend_details: read %s/%s returned %s\n",
205	    xendev->xbusd_path, path_node, val);
206	xendev->xbusd_otherend = val;
207
208	if (strlen(xendev->xbusd_otherend) == 0 ||
209	    !xenbus_exists(NULL, xendev->xbusd_otherend, "")) {
210		printf("missing other end from %s\n", xendev->xbusd_path);
211		xenbus_dev_fatal(xendev, -ENOENT, "missing other end from %s",
212				 xendev->xbusd_path);
213		free_otherend_details(xendev);
214		return ENOENT;
215	}
216
217	return 0;
218}
219
220static int
221read_backend_details(struct xenbus_device *xendev)
222{
223	return read_otherend_details(xendev, "backend-id", "backend");
224}
225
226
227static int
228read_frontend_details(struct xenbus_device *xendev)
229{
230	return read_otherend_details(xendev, "frontend-id", "frontend");
231}
232
233static void
234free_otherend_details(struct xenbus_device *dev)
235{
236	free(dev->xbusd_otherend, M_DEVBUF);
237	dev->xbusd_otherend = NULL;
238}
239
240static void
241free_otherend_watch(struct xenbus_device *dev)
242{
243	if (dev->xbusd_otherend_watch.node) {
244		unregister_xenbus_watch(&dev->xbusd_otherend_watch);
245		free(dev->xbusd_otherend_watch.node, M_DEVBUF);
246		dev->xbusd_otherend_watch.node = NULL;
247	}
248}
249
250static void
251otherend_changed(struct xenbus_watch *watch,
252			     const char **vec, unsigned int len)
253{
254	struct xenbus_device *xdev = watch->xbw_dev;
255	XenbusState state;
256
257	/* Protect us against watches firing on old details when the otherend
258	   details change, say immediately after a resume. */
259	if (!xdev->xbusd_otherend ||
260	    strncmp(xdev->xbusd_otherend, vec[XS_WATCH_PATH],
261		    strlen(xdev->xbusd_otherend))) {
262		DPRINTK("Ignoring watch at %s", vec[XS_WATCH_PATH]);
263		return;
264	}
265
266	state = xenbus_read_driver_state(xdev->xbusd_otherend);
267
268	DPRINTK("state is %d, %s, %s",
269		state, xdev->xbusd_otherend_watch.node, vec[XS_WATCH_PATH]);
270	if (state == XenbusStateClosed) {
271		int error;
272		if (xdev->xbusd_type == XENBUS_BACKEND_DEVICE) {
273			error = xdev->xbusd_u.b.b_detach(
274			    xdev->xbusd_u.b.b_cookie);
275			if (error) {
276				printf("could not detach %s: %d\n",
277				    xdev->xbusd_path, error);
278				return;
279			}
280		} else {
281			error = config_detach(xdev->xbusd_u.f.f_dev,
282			    DETACH_FORCE);
283			if (error) {
284				printf("could not detach %s: %d\n",
285				    device_xname(xdev->xbusd_u.f.f_dev), error);
286				return;
287			}
288		}
289		xenbus_free_device(xdev);
290		return;
291	}
292	if (xdev->xbusd_otherend_changed)
293		xdev->xbusd_otherend_changed(
294		    (xdev->xbusd_type == XENBUS_BACKEND_DEVICE) ?
295		    xdev->xbusd_u.b.b_cookie : xdev->xbusd_u.f.f_dev, state);
296}
297
298static int
299watch_otherend(struct xenbus_device *dev)
300{
301	free_otherend_watch(dev);
302
303	return xenbus_watch_path2(dev, dev->xbusd_otherend, "state",
304				  &dev->xbusd_otherend_watch,
305				  otherend_changed);
306}
307
308static struct xenbus_device *
309xenbus_lookup_device_path(const char *path)
310{
311	struct xenbus_device *xbusd;
312
313	SLIST_FOREACH(xbusd, &xenbus_device_list, xbusd_entries) {
314		if (strcmp(xbusd->xbusd_path, path) == 0)
315			return xbusd;
316	}
317	return NULL;
318}
319
320static int
321xenbus_probe_device_type(const char *path, const char *type,
322    int (*create)(struct xenbus_device *))
323{
324	int err, i, pos, msize;
325	int *lookup = NULL;
326	unsigned long state;
327	char **dir;
328	unsigned int dir_n = 0;
329	struct xenbus_device *xbusd;
330	struct xenbusdev_attach_args xa;
331	char *ep;
332
333	DPRINTK("probe %s type %s", path, type);
334	err = xenbus_directory(NULL, path, "", &dir_n, &dir);
335	DPRINTK("directory err %d dir_n %d", err, dir_n);
336	if (err)
337		return err;
338
339	/* Only sort frontend devices i.e. create == NULL*/
340	if (dir_n > 1 && create == NULL) {
341		int minp;
342		unsigned long minv;
343		unsigned long *id;
344
345		lookup = malloc(sizeof(int) * dir_n, M_DEVBUF,
346		    M_WAITOK | M_ZERO);
347		if (lookup == NULL)
348			panic("can't malloc lookup");
349
350		id = malloc(sizeof(unsigned long) * dir_n, M_DEVBUF,
351		    M_WAITOK | M_ZERO);
352		if (id == NULL)
353			panic("can't malloc id");
354
355		/* Convert string values to numeric; skip invalid */
356		for (i = 0; i < dir_n; i++) {
357			/*
358			 * Add one to differentiate numerical zero from invalid
359			 * string. Has no effect on sort order.
360			 */
361			id[i] = strtoul(dir[i], &ep, 10) + 1;
362			if (dir[i][0] == '\0' || *ep != '\0')
363				id[i] = 0;
364		}
365
366		/* Build lookup table in ascending order */
367		for (pos = 0; pos < dir_n; ) {
368			minv = UINT32_MAX;
369			minp = -1;
370			for (i = 0; i < dir_n; i++) {
371				if (id[i] < minv && id[i] > 0) {
372					minv = id[i];
373					minp = i;
374				}
375			}
376			if (minp >= 0) {
377				lookup[pos++] = minp;
378				id[minp] = 0;
379			}
380			else
381				break;
382		}
383
384		free(id, M_DEVBUF);
385		/* Adjust in case we had to skip non-numeric entries */
386		dir_n = pos;
387	}
388
389	for (pos = 0; pos < dir_n; pos++) {
390		err = 0;
391		if (lookup)
392			i = lookup[pos];
393		else
394			i = pos;
395		/*
396		 * add size of path to size of xenbus_device. xenbus_device
397		 * already has room for one char in xbusd_path.
398		 */
399		msize = sizeof(*xbusd) + strlen(path) + strlen(dir[i]) + 2;
400		xbusd = malloc(msize, M_DEVBUF, M_WAITOK | M_ZERO);
401		if (xbusd == NULL)
402			panic("can't malloc xbusd");
403
404		snprintf(__UNCONST(xbusd->xbusd_path),
405		    msize - sizeof(*xbusd) + 1, "%s/%s", path, dir[i]);
406		if (xenbus_lookup_device_path(xbusd->xbusd_path) != NULL) {
407			/* device already registered */
408			free(xbusd, M_DEVBUF);
409			continue;
410		}
411		err = xenbus_read_ul(NULL, xbusd->xbusd_path, "state",
412		    &state, 10);
413		if (err) {
414			printf("xenbus: can't get state "
415			    "for %s (%d)\n", xbusd->xbusd_path, err);
416			free(xbusd, M_DEVBUF);
417			err = 0;
418			continue;
419		}
420		if (state != XenbusStateInitialising) {
421			/* device is not new */
422			free(xbusd, M_DEVBUF);
423			continue;
424		}
425
426		xbusd->xbusd_otherend_watch.xbw_dev = xbusd;
427		DPRINTK("xenbus_probe_device_type probe %s\n",
428		    xbusd->xbusd_path);
429		if (create != NULL) {
430			xbusd->xbusd_type = XENBUS_BACKEND_DEVICE;
431			err = read_frontend_details(xbusd);
432			if (err != 0) {
433				printf("xenbus: can't get frontend details "
434				    "for %s (%d)\n", xbusd->xbusd_path, err);
435				break;
436			}
437			if (create(xbusd)) {
438				free(xbusd, M_DEVBUF);
439				continue;
440			}
441		} else {
442			xbusd->xbusd_type = XENBUS_FRONTEND_DEVICE;
443			xa.xa_xbusd = xbusd;
444			xa.xa_type = type;
445			xa.xa_id = strtoul(dir[i], &ep, 0);
446			if (dir[i][0] == '\0' || *ep != '\0') {
447				printf("xenbus device type %s: id %s is not a"
448				    " number\n", type, dir[i]);
449				err = EFTYPE;
450				free(xbusd, M_DEVBUF);
451				break;
452			}
453			err = read_backend_details(xbusd);
454			if (err != 0) {
455				printf("xenbus: can't get backend details "
456				    "for %s (%d)\n", xbusd->xbusd_path, err);
457				break;
458			}
459			xbusd->xbusd_u.f.f_dev = config_found_ia(xenbus_dev,
460			    "xenbus", &xa, xenbus_print);
461			if (xbusd->xbusd_u.f.f_dev == NULL) {
462				free(xbusd, M_DEVBUF);
463				continue;
464			}
465		}
466		SLIST_INSERT_HEAD(&xenbus_device_list,
467		    xbusd, xbusd_entries);
468		watch_otherend(xbusd);
469	}
470	free(dir, M_DEVBUF);
471	if (lookup)
472		free(lookup, M_DEVBUF);
473
474	return err;
475}
476
477static int
478xenbus_print(void *aux, const char *pnp)
479{
480	struct xenbusdev_attach_args *xa = aux;
481
482	if (pnp) {
483		if (strcmp(xa->xa_type, "vbd") == 0)
484			aprint_normal("xbd");
485		else if (strcmp(xa->xa_type, "vif") == 0)
486			aprint_normal("xennet");
487		else if (strcmp(xa->xa_type, "balloon") == 0)
488			aprint_normal("balloon");
489		else
490			aprint_normal("unknown type %s", xa->xa_type);
491		aprint_normal(" at %s", pnp);
492	}
493	aprint_normal(" id %d", xa->xa_id);
494	return(UNCONF);
495}
496
497static int
498xenbus_probe_frontends(void)
499{
500	int err;
501	char **dir;
502	unsigned int i, dir_n;
503	char path[30];
504
505	DPRINTK("probe device");
506	err = xenbus_directory(NULL, "device", "", &dir_n, &dir);
507	DPRINTK("directory err %d dir_n %d", err, dir_n);
508	if (err)
509		return err;
510
511	for (i = 0; i < dir_n; i++) {
512		/*
513		 * console is configured through xen_start_info when
514		 * xencons is attaching to hypervisor, so avoid console
515		 * probing when configuring xenbus devices
516		 */
517		if (strcmp(dir[i], "console") == 0)
518			continue;
519
520		snprintf(path, sizeof(path), "device/%s", dir[i]);
521		err = xenbus_probe_device_type(path, dir[i], NULL);
522		if (err)
523			break;
524	}
525	free(dir, M_DEVBUF);
526	return err;
527}
528
529static int
530xenbus_probe_backends(void)
531{
532	int err;
533	char **dirt, **dirid;
534	unsigned int type, id, dirt_n, dirid_n;
535	char path[30];
536	struct xenbus_backend_driver *xbakd;
537
538	DPRINTK("probe backend");
539	err = xenbus_directory(NULL, "backend", "", &dirt_n, &dirt);
540	DPRINTK("directory err %d dirt_n %d", err, dirt_n);
541	if (err)
542		return err;
543
544	for (type = 0; type < dirt_n; type++) {
545		SLIST_FOREACH(xbakd, &xenbus_backend_driver_list,
546		    xbakd_entries) {
547			if (strcmp(dirt[type], xbakd->xbakd_type) == 0)
548				break;
549		}
550		if (xbakd == NULL)
551			continue;
552		err = xenbus_directory(NULL, "backend", dirt[type],
553		    &dirid_n, &dirid);
554		DPRINTK("directory backend/%s err %d dirid_n %d",
555		    dirt[type], err, dirid_n);
556		if (err) {
557			free(dirt, M_DEVBUF); /* to be checked */
558			return err;
559		}
560		for (id = 0; id < dirid_n; id++) {
561			snprintf(path, sizeof(path), "backend/%s/%s",
562			    dirt[type], dirid[id]);
563			err = xenbus_probe_device_type(path, dirt[type],
564			    xbakd->xbakd_create);
565			if (err)
566				break;
567		}
568		free(dirid, M_DEVBUF);
569	}
570	free(dirt, M_DEVBUF);
571	return err;
572}
573
574int
575xenbus_free_device(struct xenbus_device *xbusd)
576{
577	KASSERT(xenbus_lookup_device_path(xbusd->xbusd_path) == xbusd);
578	SLIST_REMOVE(&xenbus_device_list, xbusd, xenbus_device, xbusd_entries);
579	free_otherend_watch(xbusd);
580	free_otherend_details(xbusd);
581	xenbus_switch_state(xbusd, NULL, XenbusStateClosed);
582	free(xbusd, M_DEVBUF);
583	return 0;
584}
585
586static void
587frontend_changed(struct xenbus_watch *watch,
588			     const char **vec, unsigned int len)
589{
590	DPRINTK("frontend_changed %s\n", vec[XS_WATCH_PATH]);
591	xenbus_probe_frontends();
592}
593
594static void
595backend_changed(struct xenbus_watch *watch,
596			    const char **vec, unsigned int len)
597{
598	DPRINTK("backend_changed %s\n", vec[XS_WATCH_PATH]);
599	xenbus_probe_backends();
600}
601
602
603/* We watch for devices appearing and vanishing. */
604static struct xenbus_watch fe_watch;
605
606static struct xenbus_watch be_watch;
607
608/* A flag to determine if xenstored is 'ready' (i.e. has started) */
609int xenstored_ready = 0;
610
611void
612xenbus_probe(void *unused)
613{
614	struct xenbusdev_attach_args balloon_xa = {
615		.xa_id = 0,
616		.xa_type = "balloon"
617	};
618
619	KASSERT((xenstored_ready > 0));
620
621	/* Enumerate devices in xenstore. */
622	xenbus_probe_frontends();
623	xenbus_probe_backends();
624
625	/* Watch for changes. */
626	fe_watch.node = malloc(strlen("device" + 1), M_DEVBUF, M_NOWAIT);
627	strcpy(fe_watch.node, "device");
628	fe_watch.xbw_callback = frontend_changed;
629	register_xenbus_watch(&fe_watch);
630	be_watch.node = malloc(strlen("backend" + 1), M_DEVBUF, M_NOWAIT);
631	strcpy(be_watch.node, "backend");
632	be_watch.xbw_callback = backend_changed;
633	register_xenbus_watch(&be_watch);
634
635	/* attach balloon. */
636	config_found_ia(xenbus_dev, "xenbus", &balloon_xa, xenbus_print);
637
638	shutdown_xenbus_setup();
639
640	/* Notify others that xenstore is up */
641	//notifier_call_chain(&xenstore_chain, 0, NULL);
642}
643
644static void
645xenbus_probe_init(void *unused)
646{
647	int err = 0;
648	bool dom0;
649	vaddr_t page = 0;
650
651	DPRINTK("");
652
653	SLIST_INIT(&xenbus_device_list);
654
655	/*
656	** Domain0 doesn't have a store_evtchn or store_mfn yet.
657	*/
658	dom0 = xendomain_is_dom0();
659	if (dom0) {
660#if defined(DOM0OPS)
661		paddr_t ma;
662		evtchn_op_t op = { .cmd = 0 };
663
664		/* Allocate page. */
665		page = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
666		    UVM_KMF_ZERO | UVM_KMF_WIRED);
667		if (!page)
668			panic("can't get xenstore page");
669
670		(void)pmap_extract_ma(pmap_kernel(), page, &ma);
671		xen_start_info.store_mfn = ma >> PAGE_SHIFT;
672		xenstore_interface = (void *)page;
673
674		/* Next allocate a local port which xenstored can bind to */
675		op.cmd = EVTCHNOP_alloc_unbound;
676		op.u.alloc_unbound.dom        = DOMID_SELF;
677		op.u.alloc_unbound.remote_dom = 0;
678
679		err = HYPERVISOR_event_channel_op(&op);
680		if (err) {
681			aprint_error_dev(xenbus_dev,
682				"can't register xenstore event\n");
683			goto err0;
684		}
685
686		xen_start_info.store_evtchn = op.u.alloc_unbound.port;
687
688		DELAY(1000);
689#else /* DOM0OPS */
690		kthread_exit(0); /* can't get a working xenstore in this case */
691#endif /* DOM0OPS */
692	}
693
694	/* Publish xenbus and Xenstore info in /kern/xen */
695	xenbus_kernfs_init();
696
697	/* register event handler */
698	xb_init_comms(xenbus_dev);
699
700	/* Initialize the interface to xenstore. */
701	err = xs_init(xenbus_dev);
702	if (err) {
703		aprint_error_dev(xenbus_dev,
704				"Error initializing xenstore comms: %i\n", err);
705		goto err0;
706	}
707
708	if (!dom0) {
709		xenstored_ready = 1;
710		xenbus_probe(NULL);
711	}
712
713	DPRINTK("done");
714	config_pending_decr();
715#ifdef DOM0OPS
716	if (dom0) {
717		int s;
718		s = spltty();
719		while (xenstored_ready == 0) {
720			tsleep(&xenstored_ready, PRIBIO, "xsready", 0);
721			xenbus_probe(NULL);
722		}
723		splx(s);
724	}
725#endif
726	kthread_exit(0);
727
728err0:
729	if (page)
730		uvm_km_free(kernel_map, page, PAGE_SIZE,
731				UVM_KMF_ZERO | UVM_KMF_WIRED);
732	kthread_exit(err);
733}
734
735/*
736 * Local variables:
737 *  c-file-style: "linux"
738 *  indent-tabs-mode: t
739 *  c-indent-level: 8
740 *  c-basic-offset: 8
741 *  tab-width: 8
742 * End:
743 */
744