1 /******************************************************************************
2 * Client-facing interface for the Xenbus driver. In other words, the
3 * interface between the Xenbus and the device-specific code, be it the
4 * frontend or the backend of that driver.
6 * Copyright (C) 2005 XenSource Ltd
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version 2
10 * as published by the Free Software Foundation; or, when distributed
11 * separately from the Linux kernel or incorporated into other
12 * software packages, subject to the following license:
14 * Permission is hereby granted, free of charge, to any person obtaining a copy
15 * of this source file (the "Software"), to deal in the Software without
16 * restriction, including without limitation the rights to use, copy, modify,
17 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
18 * and to permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
21 * The above copyright notice and this permission notice shall be included in
22 * all copies or substantial portions of the Software.
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
34 #include <linux/slab.h>
35 #include <linux/types.h>
36 #include <linux/spinlock.h>
37 #include <linux/vmalloc.h>
38 #include <linux/export.h>
39 #include <asm/xen/hypervisor.h>
41 #include <xen/interface/xen.h>
42 #include <xen/interface/event_channel.h>
43 #include <xen/balloon.h>
44 #include <xen/events.h>
45 #include <xen/grant_table.h>
46 #include <xen/xenbus.h>
48 #include <xen/features.h>
52 #define XENBUS_PAGES(_grants) (DIV_ROUND_UP(_grants, XEN_PFN_PER_PAGE))
54 #define XENBUS_MAX_RING_PAGES (XENBUS_PAGES(XENBUS_MAX_RING_GRANTS))
56 struct xenbus_map_node {
57 struct list_head next;
60 struct vm_struct *area;
63 struct page *pages[XENBUS_MAX_RING_PAGES];
64 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
68 grant_handle_t handles[XENBUS_MAX_RING_GRANTS];
69 unsigned int nr_handles;
72 struct map_ring_valloc {
73 struct xenbus_map_node *node;
75 /* Why do we need two arrays? See comment of __xenbus_map_ring */
76 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
77 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
79 struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS];
80 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
85 static DEFINE_SPINLOCK(xenbus_valloc_lock);
86 static LIST_HEAD(xenbus_valloc_pages);
88 struct xenbus_ring_ops {
89 int (*map)(struct xenbus_device *dev, struct map_ring_valloc *info,
90 grant_ref_t *gnt_refs, unsigned int nr_grefs,
92 int (*unmap)(struct xenbus_device *dev, void *vaddr);
95 static const struct xenbus_ring_ops *ring_ops __read_mostly;
97 const char *xenbus_strstate(enum xenbus_state state)
99 static const char *const name[] = {
100 [ XenbusStateUnknown ] = "Unknown",
101 [ XenbusStateInitialising ] = "Initialising",
102 [ XenbusStateInitWait ] = "InitWait",
103 [ XenbusStateInitialised ] = "Initialised",
104 [ XenbusStateConnected ] = "Connected",
105 [ XenbusStateClosing ] = "Closing",
106 [ XenbusStateClosed ] = "Closed",
107 [XenbusStateReconfiguring] = "Reconfiguring",
108 [XenbusStateReconfigured] = "Reconfigured",
110 return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID";
112 EXPORT_SYMBOL_GPL(xenbus_strstate);
115 * xenbus_watch_path - register a watch
116 * @dev: xenbus device
117 * @path: path to watch
118 * @watch: watch to register
119 * @callback: callback to register
121 * Register a @watch on the given path, using the given xenbus_watch structure
122 * for storage, and the given @callback function as the callback. Return 0 on
123 * success, or -errno on error. On success, the given @path will be saved as
124 * @watch->node, and remains the caller's to free. On error, @watch->node will
125 * be NULL, the device will switch to %XenbusStateClosing, and the error will
126 * be saved in the store.
128 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
129 struct xenbus_watch *watch,
130 bool (*will_handle)(struct xenbus_watch *,
131 const char *, const char *),
132 void (*callback)(struct xenbus_watch *,
133 const char *, const char *))
138 watch->will_handle = will_handle;
139 watch->callback = callback;
141 err = register_xenbus_watch(watch);
145 watch->will_handle = NULL;
146 watch->callback = NULL;
147 xenbus_dev_fatal(dev, err, "adding watch on %s", path);
152 EXPORT_SYMBOL_GPL(xenbus_watch_path);
156 * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path
157 * @dev: xenbus device
158 * @watch: watch to register
159 * @callback: callback to register
160 * @pathfmt: format of path to watch
162 * Register a watch on the given @path, using the given xenbus_watch
163 * structure for storage, and the given @callback function as the callback.
164 * Return 0 on success, or -errno on error. On success, the watched path
165 * (@path/@path2) will be saved as @watch->node, and becomes the caller's to
166 * kfree(). On error, watch->node will be NULL, so the caller has nothing to
167 * free, the device will switch to %XenbusStateClosing, and the error will be
168 * saved in the store.
170 int xenbus_watch_pathfmt(struct xenbus_device *dev,
171 struct xenbus_watch *watch,
172 bool (*will_handle)(struct xenbus_watch *,
173 const char *, const char *),
174 void (*callback)(struct xenbus_watch *,
175 const char *, const char *),
176 const char *pathfmt, ...)
182 va_start(ap, pathfmt);
183 path = kvasprintf(GFP_NOIO | __GFP_HIGH, pathfmt, ap);
187 xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
190 err = xenbus_watch_path(dev, path, watch, will_handle, callback);
196 EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt);
198 static void xenbus_switch_fatal(struct xenbus_device *, int, int,
202 __xenbus_switch_state(struct xenbus_device *dev,
203 enum xenbus_state state, int depth)
205 /* We check whether the state is currently set to the given value, and
206 if not, then the state is set. We don't want to unconditionally
207 write the given state, because we don't want to fire watches
208 unnecessarily. Furthermore, if the node has gone, we don't write
209 to it, as the device will be tearing down, and we don't want to
210 resurrect that directory.
212 Note that, because of this cached value of our state, this
213 function will not take a caller's Xenstore transaction
214 (something it was trying to in the past) because dev->state
215 would not get reset if the transaction was aborted.
218 struct xenbus_transaction xbt;
222 if (state == dev->state)
228 err = xenbus_transaction_start(&xbt);
230 xenbus_switch_fatal(dev, depth, err, "starting transaction");
234 err = xenbus_scanf(xbt, dev->nodename, "state", "%d", ¤t_state);
238 err = xenbus_printf(xbt, dev->nodename, "state", "%d", state);
240 xenbus_switch_fatal(dev, depth, err, "writing new state");
246 err = xenbus_transaction_end(xbt, abort);
248 if (err == -EAGAIN && !abort)
250 xenbus_switch_fatal(dev, depth, err, "ending transaction");
258 * xenbus_switch_state
259 * @dev: xenbus device
262 * Advertise in the store a change of the given driver to the given new_state.
263 * Return 0 on success, or -errno on error. On error, the device will switch
264 * to XenbusStateClosing, and the error will be saved in the store.
266 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state state)
268 return __xenbus_switch_state(dev, state, 0);
271 EXPORT_SYMBOL_GPL(xenbus_switch_state);
273 int xenbus_frontend_closed(struct xenbus_device *dev)
275 xenbus_switch_state(dev, XenbusStateClosed);
276 complete(&dev->down);
279 EXPORT_SYMBOL_GPL(xenbus_frontend_closed);
281 static void xenbus_va_dev_error(struct xenbus_device *dev, int err,
282 const char *fmt, va_list ap)
288 #define PRINTF_BUFFER_SIZE 4096
290 printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL);
294 len = sprintf(printf_buffer, "%i ", -err);
295 vsnprintf(printf_buffer + len, PRINTF_BUFFER_SIZE - len, fmt, ap);
297 dev_err(&dev->dev, "%s\n", printf_buffer);
299 path_buffer = kasprintf(GFP_KERNEL, "error/%s", dev->nodename);
301 xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer);
303 kfree(printf_buffer);
309 * @dev: xenbus device
310 * @err: error to report
311 * @fmt: error message format
313 * Report the given negative errno into the store, along with the given
316 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...)
321 xenbus_va_dev_error(dev, err, fmt, ap);
324 EXPORT_SYMBOL_GPL(xenbus_dev_error);
328 * @dev: xenbus device
329 * @err: error to report
330 * @fmt: error message format
332 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
333 * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
334 * closedown of this driver and its peer.
337 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...)
342 xenbus_va_dev_error(dev, err, fmt, ap);
345 xenbus_switch_state(dev, XenbusStateClosing);
347 EXPORT_SYMBOL_GPL(xenbus_dev_fatal);
350 * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps
351 * avoiding recursion within xenbus_switch_state.
353 static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err,
354 const char *fmt, ...)
359 xenbus_va_dev_error(dev, err, fmt, ap);
363 __xenbus_switch_state(dev, XenbusStateClosing, 1);
368 * @dev: xenbus device
369 * @vaddr: pointer to starting virtual address of the ring
370 * @nr_pages: number of pages to be granted
371 * @grefs: grant reference array to be filled in
373 * Allocate physically contiguous pages for a shared ring buffer and grant it
374 * to the peer of the given device. The ring buffer is initially filled with
375 * zeroes. The virtual address of the ring is stored at @vaddr and the
376 * grant references are stored in the @grefs array. In case of error @vaddr
377 * will be set to NULL and @grefs will be filled with INVALID_GRANT_REF.
379 int xenbus_setup_ring(struct xenbus_device *dev, gfp_t gfp, void **vaddr,
380 unsigned int nr_pages, grant_ref_t *grefs)
382 unsigned long ring_size = nr_pages * XEN_PAGE_SIZE;
383 grant_ref_t gref_head;
388 addr = *vaddr = alloc_pages_exact(ring_size, gfp | __GFP_ZERO);
394 ret = gnttab_alloc_grant_references(nr_pages, &gref_head);
396 xenbus_dev_fatal(dev, ret, "granting access to %u ring pages",
401 for (i = 0; i < nr_pages; i++) {
404 if (is_vmalloc_addr(*vaddr))
405 gfn = pfn_to_gfn(vmalloc_to_pfn(addr));
407 gfn = virt_to_gfn(addr);
409 grefs[i] = gnttab_claim_grant_reference(&gref_head);
410 gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id,
413 addr += XEN_PAGE_SIZE;
420 free_pages_exact(*vaddr, ring_size);
421 for (i = 0; i < nr_pages; i++)
422 grefs[i] = INVALID_GRANT_REF;
427 EXPORT_SYMBOL_GPL(xenbus_setup_ring);
430 * xenbus_teardown_ring
431 * @vaddr: starting virtual address of the ring
432 * @nr_pages: number of pages
433 * @grefs: grant reference array
435 * Remove grants for the shared ring buffer and free the associated memory.
436 * On return the grant reference array is filled with INVALID_GRANT_REF.
438 void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages,
443 for (i = 0; i < nr_pages; i++) {
444 if (grefs[i] != INVALID_GRANT_REF) {
445 gnttab_end_foreign_access(grefs[i], NULL);
446 grefs[i] = INVALID_GRANT_REF;
451 free_pages_exact(*vaddr, nr_pages * XEN_PAGE_SIZE);
454 EXPORT_SYMBOL_GPL(xenbus_teardown_ring);
457 * Allocate an event channel for the given xenbus_device, assigning the newly
458 * created local port to *port. Return 0 on success, or -errno on error. On
459 * error, the device will switch to XenbusStateClosing, and the error will be
460 * saved in the store.
462 int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port)
464 struct evtchn_alloc_unbound alloc_unbound;
467 alloc_unbound.dom = DOMID_SELF;
468 alloc_unbound.remote_dom = dev->otherend_id;
470 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
473 xenbus_dev_fatal(dev, err, "allocating event channel");
475 *port = alloc_unbound.port;
479 EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
483 * Free an existing event channel. Returns 0 on success or -errno on error.
485 int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port)
487 struct evtchn_close close;
492 err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
494 xenbus_dev_error(dev, err, "freeing event channel %u", port);
498 EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
502 * xenbus_map_ring_valloc
503 * @dev: xenbus device
504 * @gnt_refs: grant reference array
505 * @nr_grefs: number of grant references
506 * @vaddr: pointer to address to be filled out by mapping
508 * Map @nr_grefs pages of memory into this domain from another
509 * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
510 * pages of virtual address space, maps the pages to that address, and
511 * sets *vaddr to that address. Returns 0 on success, and -errno on
512 * error. If an error is returned, device will switch to
513 * XenbusStateClosing and the error message will be saved in XenStore.
515 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
516 unsigned int nr_grefs, void **vaddr)
519 struct map_ring_valloc *info;
523 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
526 info = kzalloc(sizeof(*info), GFP_KERNEL);
530 info->node = kzalloc(sizeof(*info->node), GFP_KERNEL);
534 err = ring_ops->map(dev, info, gnt_refs, nr_grefs, vaddr);
540 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
542 /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
543 * long), e.g. 32-on-64. Caller is responsible for preparing the
544 * right array to feed into this function */
545 static int __xenbus_map_ring(struct xenbus_device *dev,
546 grant_ref_t *gnt_refs,
547 unsigned int nr_grefs,
548 grant_handle_t *handles,
549 struct map_ring_valloc *info,
555 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
558 for (i = 0; i < nr_grefs; i++) {
559 gnttab_set_map_op(&info->map[i], info->phys_addrs[i], flags,
560 gnt_refs[i], dev->otherend_id);
561 handles[i] = INVALID_GRANT_HANDLE;
564 gnttab_batch_map(info->map, i);
566 for (i = 0; i < nr_grefs; i++) {
567 if (info->map[i].status != GNTST_okay) {
568 xenbus_dev_fatal(dev, info->map[i].status,
569 "mapping in shared page %d from domain %d",
570 gnt_refs[i], dev->otherend_id);
573 handles[i] = info->map[i].handle;
579 for (i = j = 0; i < nr_grefs; i++) {
580 if (handles[i] != INVALID_GRANT_HANDLE) {
581 gnttab_set_unmap_op(&info->unmap[j],
583 GNTMAP_host_map, handles[i]);
588 BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, info->unmap, j));
591 for (i = 0; i < j; i++) {
592 if (info->unmap[i].status != GNTST_okay) {
603 * @dev: xenbus device
604 * @handles: grant handle array
605 * @nr_handles: number of handles in the array
606 * @vaddrs: addresses to unmap
608 * Unmap memory in this domain that was imported from another domain.
609 * Returns 0 on success and returns GNTST_* on error
610 * (see xen/include/interface/grant_table.h).
612 static int xenbus_unmap_ring(struct xenbus_device *dev, grant_handle_t *handles,
613 unsigned int nr_handles, unsigned long *vaddrs)
615 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
619 if (nr_handles > XENBUS_MAX_RING_GRANTS)
622 for (i = 0; i < nr_handles; i++)
623 gnttab_set_unmap_op(&unmap[i], vaddrs[i],
624 GNTMAP_host_map, handles[i]);
626 BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i));
629 for (i = 0; i < nr_handles; i++) {
630 if (unmap[i].status != GNTST_okay) {
631 xenbus_dev_error(dev, unmap[i].status,
632 "unmapping page at handle %d error %d",
633 handles[i], unmap[i].status);
634 err = unmap[i].status;
642 static void xenbus_map_ring_setup_grant_hvm(unsigned long gfn,
643 unsigned int goffset,
647 struct map_ring_valloc *info = data;
648 unsigned long vaddr = (unsigned long)gfn_to_virt(gfn);
650 info->phys_addrs[info->idx] = vaddr;
651 info->addrs[info->idx] = vaddr;
656 static int xenbus_map_ring_hvm(struct xenbus_device *dev,
657 struct map_ring_valloc *info,
658 grant_ref_t *gnt_ref,
659 unsigned int nr_grefs,
662 struct xenbus_map_node *node = info->node;
666 unsigned int nr_pages = XENBUS_PAGES(nr_grefs);
668 err = xen_alloc_unpopulated_pages(nr_pages, node->hvm.pages);
672 gnttab_foreach_grant(node->hvm.pages, nr_grefs,
673 xenbus_map_ring_setup_grant_hvm,
676 err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles,
677 info, GNTMAP_host_map, &leaked);
678 node->nr_handles = nr_grefs;
681 goto out_free_ballooned_pages;
683 addr = vmap(node->hvm.pages, nr_pages, VM_MAP | VM_IOREMAP,
687 goto out_xenbus_unmap_ring;
690 node->hvm.addr = addr;
692 spin_lock(&xenbus_valloc_lock);
693 list_add(&node->next, &xenbus_valloc_pages);
694 spin_unlock(&xenbus_valloc_lock);
701 out_xenbus_unmap_ring:
703 xenbus_unmap_ring(dev, node->handles, nr_grefs, info->addrs);
705 pr_alert("leaking %p size %u page(s)",
707 out_free_ballooned_pages:
709 xen_free_unpopulated_pages(nr_pages, node->hvm.pages);
715 * xenbus_unmap_ring_vfree
716 * @dev: xenbus device
717 * @vaddr: addr to unmap
719 * Based on Rusty Russell's skeleton driver's unmap_page.
720 * Unmap a page of memory in this domain that was imported from another domain.
721 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
722 * xenbus_map_ring_valloc (it will free the virtual address space).
723 * Returns 0 on success and returns GNTST_* on error
724 * (see xen/include/interface/grant_table.h).
726 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
728 return ring_ops->unmap(dev, vaddr);
730 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
733 static int map_ring_apply(pte_t *pte, unsigned long addr, void *data)
735 struct map_ring_valloc *info = data;
737 info->phys_addrs[info->idx++] = arbitrary_virt_to_machine(pte).maddr;
741 static int xenbus_map_ring_pv(struct xenbus_device *dev,
742 struct map_ring_valloc *info,
743 grant_ref_t *gnt_refs,
744 unsigned int nr_grefs,
747 struct xenbus_map_node *node = info->node;
748 struct vm_struct *area;
752 area = get_vm_area(XEN_PAGE_SIZE * nr_grefs, VM_IOREMAP);
755 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
756 XEN_PAGE_SIZE * nr_grefs, map_ring_apply, info))
758 err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
759 info, GNTMAP_host_map | GNTMAP_contains_pte,
764 node->nr_handles = nr_grefs;
765 node->pv.area = area;
767 spin_lock(&xenbus_valloc_lock);
768 list_add(&node->next, &xenbus_valloc_pages);
769 spin_unlock(&xenbus_valloc_lock);
780 pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs);
785 static int xenbus_unmap_ring_pv(struct xenbus_device *dev, void *vaddr)
787 struct xenbus_map_node *node;
788 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
794 spin_lock(&xenbus_valloc_lock);
795 list_for_each_entry(node, &xenbus_valloc_pages, next) {
796 if (node->pv.area->addr == vaddr) {
797 list_del(&node->next);
803 spin_unlock(&xenbus_valloc_lock);
806 xenbus_dev_error(dev, -ENOENT,
807 "can't find mapped virtual address %p", vaddr);
808 return GNTST_bad_virt_addr;
811 for (i = 0; i < node->nr_handles; i++) {
814 memset(&unmap[i], 0, sizeof(unmap[i]));
815 addr = (unsigned long)vaddr + (XEN_PAGE_SIZE * i);
816 unmap[i].host_addr = arbitrary_virt_to_machine(
817 lookup_address(addr, &level)).maddr;
818 unmap[i].dev_bus_addr = 0;
819 unmap[i].handle = node->handles[i];
822 BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i));
826 for (i = 0; i < node->nr_handles; i++) {
827 if (unmap[i].status != GNTST_okay) {
829 xenbus_dev_error(dev, unmap[i].status,
830 "unmapping page at handle %d error %d",
831 node->handles[i], unmap[i].status);
832 err = unmap[i].status;
838 free_vm_area(node->pv.area);
840 pr_alert("leaking VM area %p size %u page(s)",
841 node->pv.area, node->nr_handles);
847 static const struct xenbus_ring_ops ring_ops_pv = {
848 .map = xenbus_map_ring_pv,
849 .unmap = xenbus_unmap_ring_pv,
853 struct unmap_ring_hvm
856 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
859 static void xenbus_unmap_ring_setup_grant_hvm(unsigned long gfn,
860 unsigned int goffset,
864 struct unmap_ring_hvm *info = data;
866 info->addrs[info->idx] = (unsigned long)gfn_to_virt(gfn);
871 static int xenbus_unmap_ring_hvm(struct xenbus_device *dev, void *vaddr)
874 struct xenbus_map_node *node;
876 struct unmap_ring_hvm info = {
879 unsigned int nr_pages;
881 spin_lock(&xenbus_valloc_lock);
882 list_for_each_entry(node, &xenbus_valloc_pages, next) {
883 addr = node->hvm.addr;
885 list_del(&node->next);
891 spin_unlock(&xenbus_valloc_lock);
894 xenbus_dev_error(dev, -ENOENT,
895 "can't find mapped virtual address %p", vaddr);
896 return GNTST_bad_virt_addr;
899 nr_pages = XENBUS_PAGES(node->nr_handles);
901 gnttab_foreach_grant(node->hvm.pages, node->nr_handles,
902 xenbus_unmap_ring_setup_grant_hvm,
905 rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
909 xen_free_unpopulated_pages(nr_pages, node->hvm.pages);
912 WARN(1, "Leaking %p, size %u page(s)\n", vaddr, nr_pages);
919 * xenbus_read_driver_state
920 * @path: path for driver
922 * Return the state of the driver rooted at the given store path, or
923 * XenbusStateUnknown if no state can be read.
925 enum xenbus_state xenbus_read_driver_state(const char *path)
927 enum xenbus_state result;
928 int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
930 result = XenbusStateUnknown;
934 EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
936 static const struct xenbus_ring_ops ring_ops_hvm = {
937 .map = xenbus_map_ring_hvm,
938 .unmap = xenbus_unmap_ring_hvm,
941 void __init xenbus_ring_ops_init(void)
944 if (!xen_feature(XENFEAT_auto_translated_physmap))
945 ring_ops = &ring_ops_pv;
948 ring_ops = &ring_ops_hvm;