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32
33#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34#define dev_fmt pr_fmt
35
36#define DPRINTK(fmt, args...) \
37 pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \
38 __func__, __LINE__, ##args)
39
40#include <linux/kernel.h>
41#include <linux/err.h>
42#include <linux/string.h>
43#include <linux/ctype.h>
44#include <linux/fcntl.h>
45#include <linux/mm.h>
46#include <linux/proc_fs.h>
47#include <linux/notifier.h>
48#include <linux/kthread.h>
49#include <linux/mutex.h>
50#include <linux/io.h>
51#include <linux/slab.h>
52#include <linux/module.h>
53
54#include <asm/page.h>
55#include <asm/xen/hypervisor.h>
56
57#include <xen/xen.h>
58#include <xen/xenbus.h>
59#include <xen/events.h>
60#include <xen/xen-ops.h>
61#include <xen/page.h>
62
63#include <xen/hvm.h>
64
65#include "xenbus.h"
66
67
68int xen_store_evtchn;
69EXPORT_SYMBOL_GPL(xen_store_evtchn);
70
71struct xenstore_domain_interface *xen_store_interface;
72EXPORT_SYMBOL_GPL(xen_store_interface);
73
74enum xenstore_init xen_store_domain_type;
75EXPORT_SYMBOL_GPL(xen_store_domain_type);
76
77static unsigned long xen_store_gfn;
78
79static BLOCKING_NOTIFIER_HEAD(xenstore_chain);
80
81
82static const struct xenbus_device_id *
83match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev)
84{
85 for (; *arr->devicetype != '\0'; arr++) {
86 if (!strcmp(arr->devicetype, dev->devicetype))
87 return arr;
88 }
89 return NULL;
90}
91
92int xenbus_match(struct device *_dev, struct device_driver *_drv)
93{
94 struct xenbus_driver *drv = to_xenbus_driver(_drv);
95
96 if (!drv->ids)
97 return 0;
98
99 return match_device(drv->ids, to_xenbus_device(_dev)) != NULL;
100}
101EXPORT_SYMBOL_GPL(xenbus_match);
102
103
104static void free_otherend_details(struct xenbus_device *dev)
105{
106 kfree(dev->otherend);
107 dev->otherend = NULL;
108}
109
110
111static void free_otherend_watch(struct xenbus_device *dev)
112{
113 if (dev->otherend_watch.node) {
114 unregister_xenbus_watch(&dev->otherend_watch);
115 kfree(dev->otherend_watch.node);
116 dev->otherend_watch.node = NULL;
117 }
118}
119
120
121static int talk_to_otherend(struct xenbus_device *dev)
122{
123 struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver);
124
125 free_otherend_watch(dev);
126 free_otherend_details(dev);
127
128 return drv->read_otherend_details(dev);
129}
130
131
132
133static int watch_otherend(struct xenbus_device *dev)
134{
135 struct xen_bus_type *bus =
136 container_of(dev->dev.bus, struct xen_bus_type, bus);
137
138 return xenbus_watch_pathfmt(dev, &dev->otherend_watch,
139 bus->otherend_will_handle,
140 bus->otherend_changed,
141 "%s/%s", dev->otherend, "state");
142}
143
144
145int xenbus_read_otherend_details(struct xenbus_device *xendev,
146 char *id_node, char *path_node)
147{
148 int err = xenbus_gather(XBT_NIL, xendev->nodename,
149 id_node, "%i", &xendev->otherend_id,
150 path_node, NULL, &xendev->otherend,
151 NULL);
152 if (err) {
153 xenbus_dev_fatal(xendev, err,
154 "reading other end details from %s",
155 xendev->nodename);
156 return err;
157 }
158 if (strlen(xendev->otherend) == 0 ||
159 !xenbus_exists(XBT_NIL, xendev->otherend, "")) {
160 xenbus_dev_fatal(xendev, -ENOENT,
161 "unable to read other end from %s. "
162 "missing or inaccessible.",
163 xendev->nodename);
164 free_otherend_details(xendev);
165 return -ENOENT;
166 }
167
168 return 0;
169}
170EXPORT_SYMBOL_GPL(xenbus_read_otherend_details);
171
172void xenbus_otherend_changed(struct xenbus_watch *watch,
173 const char *path, const char *token,
174 int ignore_on_shutdown)
175{
176 struct xenbus_device *dev =
177 container_of(watch, struct xenbus_device, otherend_watch);
178 struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver);
179 enum xenbus_state state;
180
181
182
183 if (!dev->otherend ||
184 strncmp(dev->otherend, path, strlen(dev->otherend))) {
185 dev_dbg(&dev->dev, "Ignoring watch at %s\n", path);
186 return;
187 }
188
189 state = xenbus_read_driver_state(dev->otherend);
190
191 dev_dbg(&dev->dev, "state is %d, (%s), %s, %s\n",
192 state, xenbus_strstate(state), dev->otherend_watch.node, path);
193
194
195
196
197
198 if (system_state > SYSTEM_RUNNING) {
199 if (ignore_on_shutdown && (state == XenbusStateClosing))
200 xenbus_frontend_closed(dev);
201 return;
202 }
203
204 if (drv->otherend_changed)
205 drv->otherend_changed(dev, state);
206}
207EXPORT_SYMBOL_GPL(xenbus_otherend_changed);
208
209#define XENBUS_SHOW_STAT(name) \
210static ssize_t name##_show(struct device *_dev, \
211 struct device_attribute *attr, \
212 char *buf) \
213{ \
214 struct xenbus_device *dev = to_xenbus_device(_dev); \
215 \
216 return sprintf(buf, "%d\n", atomic_read(&dev->name)); \
217} \
218static DEVICE_ATTR_RO(name)
219
220XENBUS_SHOW_STAT(event_channels);
221XENBUS_SHOW_STAT(events);
222XENBUS_SHOW_STAT(spurious_events);
223XENBUS_SHOW_STAT(jiffies_eoi_delayed);
224
225static ssize_t spurious_threshold_show(struct device *_dev,
226 struct device_attribute *attr,
227 char *buf)
228{
229 struct xenbus_device *dev = to_xenbus_device(_dev);
230
231 return sprintf(buf, "%d\n", dev->spurious_threshold);
232}
233
234static ssize_t spurious_threshold_store(struct device *_dev,
235 struct device_attribute *attr,
236 const char *buf, size_t count)
237{
238 struct xenbus_device *dev = to_xenbus_device(_dev);
239 unsigned int val;
240 ssize_t ret;
241
242 ret = kstrtouint(buf, 0, &val);
243 if (ret)
244 return ret;
245
246 dev->spurious_threshold = val;
247
248 return count;
249}
250
251static DEVICE_ATTR_RW(spurious_threshold);
252
253static struct attribute *xenbus_attrs[] = {
254 &dev_attr_event_channels.attr,
255 &dev_attr_events.attr,
256 &dev_attr_spurious_events.attr,
257 &dev_attr_jiffies_eoi_delayed.attr,
258 &dev_attr_spurious_threshold.attr,
259 NULL
260};
261
262static const struct attribute_group xenbus_group = {
263 .name = "xenbus",
264 .attrs = xenbus_attrs,
265};
266
267int xenbus_dev_probe(struct device *_dev)
268{
269 struct xenbus_device *dev = to_xenbus_device(_dev);
270 struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
271 const struct xenbus_device_id *id;
272 int err;
273
274 DPRINTK("%s", dev->nodename);
275
276 if (!drv->probe) {
277 err = -ENODEV;
278 goto fail;
279 }
280
281 id = match_device(drv->ids, dev);
282 if (!id) {
283 err = -ENODEV;
284 goto fail;
285 }
286
287 err = talk_to_otherend(dev);
288 if (err) {
289 dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n",
290 dev->nodename);
291 return err;
292 }
293
294 if (!try_module_get(drv->driver.owner)) {
295 dev_warn(&dev->dev, "failed to acquire module reference on '%s'\n",
296 drv->driver.name);
297 err = -ESRCH;
298 goto fail;
299 }
300
301 down(&dev->reclaim_sem);
302 err = drv->probe(dev, id);
303 up(&dev->reclaim_sem);
304 if (err)
305 goto fail_put;
306
307 err = watch_otherend(dev);
308 if (err) {
309 dev_warn(&dev->dev, "watch_otherend on %s failed.\n",
310 dev->nodename);
311 return err;
312 }
313
314 dev->spurious_threshold = 1;
315 if (sysfs_create_group(&dev->dev.kobj, &xenbus_group))
316 dev_warn(&dev->dev, "sysfs_create_group on %s failed.\n",
317 dev->nodename);
318
319 return 0;
320fail_put:
321 module_put(drv->driver.owner);
322fail:
323 xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
324 return err;
325}
326EXPORT_SYMBOL_GPL(xenbus_dev_probe);
327
328void xenbus_dev_remove(struct device *_dev)
329{
330 struct xenbus_device *dev = to_xenbus_device(_dev);
331 struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
332
333 DPRINTK("%s", dev->nodename);
334
335 sysfs_remove_group(&dev->dev.kobj, &xenbus_group);
336
337 free_otherend_watch(dev);
338
339 if (drv->remove) {
340 down(&dev->reclaim_sem);
341 drv->remove(dev);
342 up(&dev->reclaim_sem);
343 }
344
345 module_put(drv->driver.owner);
346
347 free_otherend_details(dev);
348
349
350
351
352
353
354
355 if (!drv->allow_rebind ||
356 xenbus_read_driver_state(dev->nodename) == XenbusStateClosing)
357 xenbus_switch_state(dev, XenbusStateClosed);
358}
359EXPORT_SYMBOL_GPL(xenbus_dev_remove);
360
361int xenbus_register_driver_common(struct xenbus_driver *drv,
362 struct xen_bus_type *bus,
363 struct module *owner, const char *mod_name)
364{
365 drv->driver.name = drv->name ? drv->name : drv->ids[0].devicetype;
366 drv->driver.bus = &bus->bus;
367 drv->driver.owner = owner;
368 drv->driver.mod_name = mod_name;
369
370 return driver_register(&drv->driver);
371}
372EXPORT_SYMBOL_GPL(xenbus_register_driver_common);
373
374void xenbus_unregister_driver(struct xenbus_driver *drv)
375{
376 driver_unregister(&drv->driver);
377}
378EXPORT_SYMBOL_GPL(xenbus_unregister_driver);
379
380struct xb_find_info {
381 struct xenbus_device *dev;
382 const char *nodename;
383};
384
385static int cmp_dev(struct device *dev, void *data)
386{
387 struct xenbus_device *xendev = to_xenbus_device(dev);
388 struct xb_find_info *info = data;
389
390 if (!strcmp(xendev->nodename, info->nodename)) {
391 info->dev = xendev;
392 get_device(dev);
393 return 1;
394 }
395 return 0;
396}
397
398static struct xenbus_device *xenbus_device_find(const char *nodename,
399 struct bus_type *bus)
400{
401 struct xb_find_info info = { .dev = NULL, .nodename = nodename };
402
403 bus_for_each_dev(bus, NULL, &info, cmp_dev);
404 return info.dev;
405}
406
407static int cleanup_dev(struct device *dev, void *data)
408{
409 struct xenbus_device *xendev = to_xenbus_device(dev);
410 struct xb_find_info *info = data;
411 int len = strlen(info->nodename);
412
413 DPRINTK("%s", info->nodename);
414
415
416 if (strncmp(xendev->nodename, info->nodename, len))
417 return 0;
418
419
420 if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/'))
421 return 0;
422
423 info->dev = xendev;
424 get_device(dev);
425 return 1;
426}
427
428static void xenbus_cleanup_devices(const char *path, struct bus_type *bus)
429{
430 struct xb_find_info info = { .nodename = path };
431
432 do {
433 info.dev = NULL;
434 bus_for_each_dev(bus, NULL, &info, cleanup_dev);
435 if (info.dev) {
436 device_unregister(&info.dev->dev);
437 put_device(&info.dev->dev);
438 }
439 } while (info.dev);
440}
441
442static void xenbus_dev_release(struct device *dev)
443{
444 if (dev)
445 kfree(to_xenbus_device(dev));
446}
447
448static ssize_t nodename_show(struct device *dev,
449 struct device_attribute *attr, char *buf)
450{
451 return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename);
452}
453static DEVICE_ATTR_RO(nodename);
454
455static ssize_t devtype_show(struct device *dev,
456 struct device_attribute *attr, char *buf)
457{
458 return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype);
459}
460static DEVICE_ATTR_RO(devtype);
461
462static ssize_t modalias_show(struct device *dev,
463 struct device_attribute *attr, char *buf)
464{
465 return sprintf(buf, "%s:%s\n", dev->bus->name,
466 to_xenbus_device(dev)->devicetype);
467}
468static DEVICE_ATTR_RO(modalias);
469
470static ssize_t state_show(struct device *dev,
471 struct device_attribute *attr, char *buf)
472{
473 return sprintf(buf, "%s\n",
474 xenbus_strstate(to_xenbus_device(dev)->state));
475}
476static DEVICE_ATTR_RO(state);
477
478static struct attribute *xenbus_dev_attrs[] = {
479 &dev_attr_nodename.attr,
480 &dev_attr_devtype.attr,
481 &dev_attr_modalias.attr,
482 &dev_attr_state.attr,
483 NULL,
484};
485
486static const struct attribute_group xenbus_dev_group = {
487 .attrs = xenbus_dev_attrs,
488};
489
490const struct attribute_group *xenbus_dev_groups[] = {
491 &xenbus_dev_group,
492 NULL,
493};
494EXPORT_SYMBOL_GPL(xenbus_dev_groups);
495
496int xenbus_probe_node(struct xen_bus_type *bus,
497 const char *type,
498 const char *nodename)
499{
500 char devname[XEN_BUS_ID_SIZE];
501 int err;
502 struct xenbus_device *xendev;
503 size_t stringlen;
504 char *tmpstring;
505
506 enum xenbus_state state = xenbus_read_driver_state(nodename);
507
508 if (state != XenbusStateInitialising) {
509
510
511 return 0;
512 }
513
514 stringlen = strlen(nodename) + 1 + strlen(type) + 1;
515 xendev = kzalloc(sizeof(*xendev) + stringlen, GFP_KERNEL);
516 if (!xendev)
517 return -ENOMEM;
518
519 xendev->state = XenbusStateInitialising;
520
521
522
523 tmpstring = (char *)(xendev + 1);
524 strcpy(tmpstring, nodename);
525 xendev->nodename = tmpstring;
526
527 tmpstring += strlen(tmpstring) + 1;
528 strcpy(tmpstring, type);
529 xendev->devicetype = tmpstring;
530 init_completion(&xendev->down);
531
532 xendev->dev.bus = &bus->bus;
533 xendev->dev.release = xenbus_dev_release;
534
535 err = bus->get_bus_id(devname, xendev->nodename);
536 if (err)
537 goto fail;
538
539 dev_set_name(&xendev->dev, "%s", devname);
540 sema_init(&xendev->reclaim_sem, 1);
541
542
543 err = device_register(&xendev->dev);
544 if (err) {
545 put_device(&xendev->dev);
546 xendev = NULL;
547 goto fail;
548 }
549
550 return 0;
551fail:
552 kfree(xendev);
553 return err;
554}
555EXPORT_SYMBOL_GPL(xenbus_probe_node);
556
557static int xenbus_probe_device_type(struct xen_bus_type *bus, const char *type)
558{
559 int err = 0;
560 char **dir;
561 unsigned int dir_n = 0;
562 int i;
563
564 dir = xenbus_directory(XBT_NIL, bus->root, type, &dir_n);
565 if (IS_ERR(dir))
566 return PTR_ERR(dir);
567
568 for (i = 0; i < dir_n; i++) {
569 err = bus->probe(bus, type, dir[i]);
570 if (err)
571 break;
572 }
573
574 kfree(dir);
575 return err;
576}
577
578int xenbus_probe_devices(struct xen_bus_type *bus)
579{
580 int err = 0;
581 char **dir;
582 unsigned int i, dir_n;
583
584 dir = xenbus_directory(XBT_NIL, bus->root, "", &dir_n);
585 if (IS_ERR(dir))
586 return PTR_ERR(dir);
587
588 for (i = 0; i < dir_n; i++) {
589 err = xenbus_probe_device_type(bus, dir[i]);
590 if (err)
591 break;
592 }
593
594 kfree(dir);
595 return err;
596}
597EXPORT_SYMBOL_GPL(xenbus_probe_devices);
598
599static unsigned int char_count(const char *str, char c)
600{
601 unsigned int i, ret = 0;
602
603 for (i = 0; str[i]; i++)
604 if (str[i] == c)
605 ret++;
606 return ret;
607}
608
609static int strsep_len(const char *str, char c, unsigned int len)
610{
611 unsigned int i;
612
613 for (i = 0; str[i]; i++)
614 if (str[i] == c) {
615 if (len == 0)
616 return i;
617 len--;
618 }
619 return (len == 0) ? i : -ERANGE;
620}
621
622void xenbus_dev_changed(const char *node, struct xen_bus_type *bus)
623{
624 int exists, rootlen;
625 struct xenbus_device *dev;
626 char type[XEN_BUS_ID_SIZE];
627 const char *p, *root;
628
629 if (char_count(node, '/') < 2)
630 return;
631
632 exists = xenbus_exists(XBT_NIL, node, "");
633 if (!exists) {
634 xenbus_cleanup_devices(node, &bus->bus);
635 return;
636 }
637
638
639 p = strchr(node, '/') + 1;
640 snprintf(type, XEN_BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p);
641 type[XEN_BUS_ID_SIZE-1] = '\0';
642
643 rootlen = strsep_len(node, '/', bus->levels);
644 if (rootlen < 0)
645 return;
646 root = kasprintf(GFP_KERNEL, "%.*s", rootlen, node);
647 if (!root)
648 return;
649
650 dev = xenbus_device_find(root, &bus->bus);
651 if (!dev)
652 xenbus_probe_node(bus, type, root);
653 else
654 put_device(&dev->dev);
655
656 kfree(root);
657}
658EXPORT_SYMBOL_GPL(xenbus_dev_changed);
659
660int xenbus_dev_suspend(struct device *dev)
661{
662 int err = 0;
663 struct xenbus_driver *drv;
664 struct xenbus_device *xdev
665 = container_of(dev, struct xenbus_device, dev);
666
667 DPRINTK("%s", xdev->nodename);
668
669 if (dev->driver == NULL)
670 return 0;
671 drv = to_xenbus_driver(dev->driver);
672 if (drv->suspend)
673 err = drv->suspend(xdev);
674 if (err)
675 dev_warn(dev, "suspend failed: %i\n", err);
676 return 0;
677}
678EXPORT_SYMBOL_GPL(xenbus_dev_suspend);
679
680int xenbus_dev_resume(struct device *dev)
681{
682 int err;
683 struct xenbus_driver *drv;
684 struct xenbus_device *xdev
685 = container_of(dev, struct xenbus_device, dev);
686
687 DPRINTK("%s", xdev->nodename);
688
689 if (dev->driver == NULL)
690 return 0;
691 drv = to_xenbus_driver(dev->driver);
692 err = talk_to_otherend(xdev);
693 if (err) {
694 dev_warn(dev, "resume (talk_to_otherend) failed: %i\n", err);
695 return err;
696 }
697
698 xdev->state = XenbusStateInitialising;
699
700 if (drv->resume) {
701 err = drv->resume(xdev);
702 if (err) {
703 dev_warn(dev, "resume failed: %i\n", err);
704 return err;
705 }
706 }
707
708 err = watch_otherend(xdev);
709 if (err) {
710 dev_warn(dev, "resume (watch_otherend) failed: %d\n", err);
711 return err;
712 }
713
714 return 0;
715}
716EXPORT_SYMBOL_GPL(xenbus_dev_resume);
717
718int xenbus_dev_cancel(struct device *dev)
719{
720
721 DPRINTK("cancel");
722 return 0;
723}
724EXPORT_SYMBOL_GPL(xenbus_dev_cancel);
725
726
727int xenstored_ready;
728
729
730int register_xenstore_notifier(struct notifier_block *nb)
731{
732 int ret = 0;
733
734 if (xenstored_ready > 0)
735 ret = nb->notifier_call(nb, 0, NULL);
736 else
737 blocking_notifier_chain_register(&xenstore_chain, nb);
738
739 return ret;
740}
741EXPORT_SYMBOL_GPL(register_xenstore_notifier);
742
743void unregister_xenstore_notifier(struct notifier_block *nb)
744{
745 blocking_notifier_chain_unregister(&xenstore_chain, nb);
746}
747EXPORT_SYMBOL_GPL(unregister_xenstore_notifier);
748
749static void xenbus_probe(void)
750{
751 xenstored_ready = 1;
752
753
754
755
756
757
758 if (xen_store_domain_type == XS_HVM)
759 xs_init();
760
761
762 blocking_notifier_call_chain(&xenstore_chain, 0, NULL);
763}
764
765
766
767
768
769
770static bool xs_hvm_defer_init_for_callback(void)
771{
772#ifdef CONFIG_XEN_PVHVM
773 return xen_store_domain_type == XS_HVM &&
774 !xen_have_vector_callback;
775#else
776 return false;
777#endif
778}
779
780static int xenbus_probe_thread(void *unused)
781{
782 DEFINE_WAIT(w);
783
784
785
786
787
788 prepare_to_wait(&xb_waitq, &w, TASK_INTERRUPTIBLE);
789 schedule();
790 finish_wait(&xb_waitq, &w);
791
792 DPRINTK("probing");
793 xenbus_probe();
794 return 0;
795}
796
797static int __init xenbus_probe_initcall(void)
798{
799
800
801
802
803 if (xen_store_domain_type == XS_PV ||
804 (xen_store_domain_type == XS_HVM &&
805 !xs_hvm_defer_init_for_callback()))
806 xenbus_probe();
807
808
809
810
811
812
813
814 if (xen_store_domain_type == XS_LOCAL) {
815 struct task_struct *probe_task;
816
817 probe_task = kthread_run(xenbus_probe_thread, NULL,
818 "xenbus_probe");
819 if (IS_ERR(probe_task))
820 return PTR_ERR(probe_task);
821 }
822 return 0;
823}
824device_initcall(xenbus_probe_initcall);
825
826int xen_set_callback_via(uint64_t via)
827{
828 struct xen_hvm_param a;
829 int ret;
830
831 a.domid = DOMID_SELF;
832 a.index = HVM_PARAM_CALLBACK_IRQ;
833 a.value = via;
834
835 ret = HYPERVISOR_hvm_op(HVMOP_set_param, &a);
836 if (ret)
837 return ret;
838
839
840
841
842
843 if (!xenstored_ready && xs_hvm_defer_init_for_callback())
844 xenbus_probe();
845
846 return ret;
847}
848EXPORT_SYMBOL_GPL(xen_set_callback_via);
849
850
851
852
853static int __init xenstored_local_init(void)
854{
855 int err = -ENOMEM;
856 unsigned long page = 0;
857 struct evtchn_alloc_unbound alloc_unbound;
858
859
860 page = get_zeroed_page(GFP_KERNEL);
861 if (!page)
862 goto out_err;
863
864 xen_store_gfn = virt_to_gfn((void *)page);
865
866
867 alloc_unbound.dom = DOMID_SELF;
868 alloc_unbound.remote_dom = DOMID_SELF;
869
870 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
871 &alloc_unbound);
872 if (err == -ENOSYS)
873 goto out_err;
874
875 BUG_ON(err);
876 xen_store_evtchn = alloc_unbound.port;
877
878 return 0;
879
880 out_err:
881 if (page != 0)
882 free_page(page);
883 return err;
884}
885
886static int xenbus_resume_cb(struct notifier_block *nb,
887 unsigned long action, void *data)
888{
889 int err = 0;
890
891 if (xen_hvm_domain()) {
892 uint64_t v = 0;
893
894 err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
895 if (!err && v)
896 xen_store_evtchn = v;
897 else
898 pr_warn("Cannot update xenstore event channel: %d\n",
899 err);
900 } else
901 xen_store_evtchn = xen_start_info->store_evtchn;
902
903 return err;
904}
905
906static struct notifier_block xenbus_resume_nb = {
907 .notifier_call = xenbus_resume_cb,
908};
909
910static int __init xenbus_init(void)
911{
912 int err = 0;
913 uint64_t v = 0;
914 xen_store_domain_type = XS_UNKNOWN;
915
916 if (!xen_domain())
917 return -ENODEV;
918
919 xenbus_ring_ops_init();
920
921 if (xen_pv_domain())
922 xen_store_domain_type = XS_PV;
923 if (xen_hvm_domain())
924 xen_store_domain_type = XS_HVM;
925 if (xen_hvm_domain() && xen_initial_domain())
926 xen_store_domain_type = XS_LOCAL;
927 if (xen_pv_domain() && !xen_start_info->store_evtchn)
928 xen_store_domain_type = XS_LOCAL;
929 if (xen_pv_domain() && xen_start_info->store_evtchn)
930 xenstored_ready = 1;
931
932 switch (xen_store_domain_type) {
933 case XS_LOCAL:
934 err = xenstored_local_init();
935 if (err)
936 goto out_error;
937 xen_store_interface = gfn_to_virt(xen_store_gfn);
938 break;
939 case XS_PV:
940 xen_store_evtchn = xen_start_info->store_evtchn;
941 xen_store_gfn = xen_start_info->store_mfn;
942 xen_store_interface = gfn_to_virt(xen_store_gfn);
943 break;
944 case XS_HVM:
945 err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
946 if (err)
947 goto out_error;
948 xen_store_evtchn = (int)v;
949 err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
950 if (err)
951 goto out_error;
952 xen_store_gfn = (unsigned long)v;
953 xen_store_interface =
954 xen_remap(xen_store_gfn << XEN_PAGE_SHIFT,
955 XEN_PAGE_SIZE);
956 break;
957 default:
958 pr_warn("Xenstore state unknown\n");
959 break;
960 }
961
962
963
964
965
966
967 if (xen_store_domain_type != XS_HVM) {
968 err = xs_init();
969 if (err) {
970 pr_warn("Error initializing xenstore comms: %i\n", err);
971 goto out_error;
972 }
973 }
974
975 if ((xen_store_domain_type != XS_LOCAL) &&
976 (xen_store_domain_type != XS_UNKNOWN))
977 xen_resume_notifier_register(&xenbus_resume_nb);
978
979#ifdef CONFIG_XEN_COMPAT_XENFS
980
981
982
983
984 proc_create_mount_point("xen");
985#endif
986
987out_error:
988 return err;
989}
990
991postcore_initcall(xenbus_init);
992
993MODULE_LICENSE("GPL");
994