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;
387 *vaddr = alloc_pages_exact(ring_size, gfp | __GFP_ZERO);
393 ret = gnttab_alloc_grant_references(nr_pages, &gref_head);
395 xenbus_dev_fatal(dev, ret, "granting access to %u ring pages",
400 for (i = 0; i < nr_pages; i++) {
403 if (is_vmalloc_addr(*vaddr))
404 gfn = pfn_to_gfn(vmalloc_to_pfn(vaddr[i]));
406 gfn = virt_to_gfn(vaddr[i]);
408 grefs[i] = gnttab_claim_grant_reference(&gref_head);
409 gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id,
417 free_pages_exact(*vaddr, ring_size);
418 for (i = 0; i < nr_pages; i++)
419 grefs[i] = INVALID_GRANT_REF;
424 EXPORT_SYMBOL_GPL(xenbus_setup_ring);
427 * xenbus_teardown_ring
428 * @vaddr: starting virtual address of the ring
429 * @nr_pages: number of pages
430 * @grefs: grant reference array
432 * Remove grants for the shared ring buffer and free the associated memory.
433 * On return the grant reference array is filled with INVALID_GRANT_REF.
435 void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages,
440 for (i = 0; i < nr_pages; i++) {
441 if (grefs[i] != INVALID_GRANT_REF) {
442 gnttab_end_foreign_access(grefs[i], NULL);
443 grefs[i] = INVALID_GRANT_REF;
448 free_pages_exact(*vaddr, nr_pages * XEN_PAGE_SIZE);
451 EXPORT_SYMBOL_GPL(xenbus_teardown_ring);
454 * Allocate an event channel for the given xenbus_device, assigning the newly
455 * created local port to *port. Return 0 on success, or -errno on error. On
456 * error, the device will switch to XenbusStateClosing, and the error will be
457 * saved in the store.
459 int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port)
461 struct evtchn_alloc_unbound alloc_unbound;
464 alloc_unbound.dom = DOMID_SELF;
465 alloc_unbound.remote_dom = dev->otherend_id;
467 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
470 xenbus_dev_fatal(dev, err, "allocating event channel");
472 *port = alloc_unbound.port;
476 EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
480 * Free an existing event channel. Returns 0 on success or -errno on error.
482 int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port)
484 struct evtchn_close close;
489 err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
491 xenbus_dev_error(dev, err, "freeing event channel %u", port);
495 EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
499 * xenbus_map_ring_valloc
500 * @dev: xenbus device
501 * @gnt_refs: grant reference array
502 * @nr_grefs: number of grant references
503 * @vaddr: pointer to address to be filled out by mapping
505 * Map @nr_grefs pages of memory into this domain from another
506 * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
507 * pages of virtual address space, maps the pages to that address, and
508 * sets *vaddr to that address. Returns 0 on success, and -errno on
509 * error. If an error is returned, device will switch to
510 * XenbusStateClosing and the error message will be saved in XenStore.
512 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
513 unsigned int nr_grefs, void **vaddr)
516 struct map_ring_valloc *info;
520 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
523 info = kzalloc(sizeof(*info), GFP_KERNEL);
527 info->node = kzalloc(sizeof(*info->node), GFP_KERNEL);
531 err = ring_ops->map(dev, info, gnt_refs, nr_grefs, vaddr);
537 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
539 /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
540 * long), e.g. 32-on-64. Caller is responsible for preparing the
541 * right array to feed into this function */
542 static int __xenbus_map_ring(struct xenbus_device *dev,
543 grant_ref_t *gnt_refs,
544 unsigned int nr_grefs,
545 grant_handle_t *handles,
546 struct map_ring_valloc *info,
552 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
555 for (i = 0; i < nr_grefs; i++) {
556 gnttab_set_map_op(&info->map[i], info->phys_addrs[i], flags,
557 gnt_refs[i], dev->otherend_id);
558 handles[i] = INVALID_GRANT_HANDLE;
561 gnttab_batch_map(info->map, i);
563 for (i = 0; i < nr_grefs; i++) {
564 if (info->map[i].status != GNTST_okay) {
565 xenbus_dev_fatal(dev, info->map[i].status,
566 "mapping in shared page %d from domain %d",
567 gnt_refs[i], dev->otherend_id);
570 handles[i] = info->map[i].handle;
576 for (i = j = 0; i < nr_grefs; i++) {
577 if (handles[i] != INVALID_GRANT_HANDLE) {
578 gnttab_set_unmap_op(&info->unmap[j],
580 GNTMAP_host_map, handles[i]);
585 BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, info->unmap, j));
588 for (i = 0; i < j; i++) {
589 if (info->unmap[i].status != GNTST_okay) {
600 * @dev: xenbus device
601 * @handles: grant handle array
602 * @nr_handles: number of handles in the array
603 * @vaddrs: addresses to unmap
605 * Unmap memory in this domain that was imported from another domain.
606 * Returns 0 on success and returns GNTST_* on error
607 * (see xen/include/interface/grant_table.h).
609 static int xenbus_unmap_ring(struct xenbus_device *dev, grant_handle_t *handles,
610 unsigned int nr_handles, unsigned long *vaddrs)
612 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
616 if (nr_handles > XENBUS_MAX_RING_GRANTS)
619 for (i = 0; i < nr_handles; i++)
620 gnttab_set_unmap_op(&unmap[i], vaddrs[i],
621 GNTMAP_host_map, handles[i]);
623 BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i));
626 for (i = 0; i < nr_handles; i++) {
627 if (unmap[i].status != GNTST_okay) {
628 xenbus_dev_error(dev, unmap[i].status,
629 "unmapping page at handle %d error %d",
630 handles[i], unmap[i].status);
631 err = unmap[i].status;
639 static void xenbus_map_ring_setup_grant_hvm(unsigned long gfn,
640 unsigned int goffset,
644 struct map_ring_valloc *info = data;
645 unsigned long vaddr = (unsigned long)gfn_to_virt(gfn);
647 info->phys_addrs[info->idx] = vaddr;
648 info->addrs[info->idx] = vaddr;
653 static int xenbus_map_ring_hvm(struct xenbus_device *dev,
654 struct map_ring_valloc *info,
655 grant_ref_t *gnt_ref,
656 unsigned int nr_grefs,
659 struct xenbus_map_node *node = info->node;
663 unsigned int nr_pages = XENBUS_PAGES(nr_grefs);
665 err = xen_alloc_unpopulated_pages(nr_pages, node->hvm.pages);
669 gnttab_foreach_grant(node->hvm.pages, nr_grefs,
670 xenbus_map_ring_setup_grant_hvm,
673 err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles,
674 info, GNTMAP_host_map, &leaked);
675 node->nr_handles = nr_grefs;
678 goto out_free_ballooned_pages;
680 addr = vmap(node->hvm.pages, nr_pages, VM_MAP | VM_IOREMAP,
684 goto out_xenbus_unmap_ring;
687 node->hvm.addr = addr;
689 spin_lock(&xenbus_valloc_lock);
690 list_add(&node->next, &xenbus_valloc_pages);
691 spin_unlock(&xenbus_valloc_lock);
698 out_xenbus_unmap_ring:
700 xenbus_unmap_ring(dev, node->handles, nr_grefs, info->addrs);
702 pr_alert("leaking %p size %u page(s)",
704 out_free_ballooned_pages:
706 xen_free_unpopulated_pages(nr_pages, node->hvm.pages);
712 * xenbus_unmap_ring_vfree
713 * @dev: xenbus device
714 * @vaddr: addr to unmap
716 * Based on Rusty Russell's skeleton driver's unmap_page.
717 * Unmap a page of memory in this domain that was imported from another domain.
718 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
719 * xenbus_map_ring_valloc (it will free the virtual address space).
720 * Returns 0 on success and returns GNTST_* on error
721 * (see xen/include/interface/grant_table.h).
723 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
725 return ring_ops->unmap(dev, vaddr);
727 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
730 static int map_ring_apply(pte_t *pte, unsigned long addr, void *data)
732 struct map_ring_valloc *info = data;
734 info->phys_addrs[info->idx++] = arbitrary_virt_to_machine(pte).maddr;
738 static int xenbus_map_ring_pv(struct xenbus_device *dev,
739 struct map_ring_valloc *info,
740 grant_ref_t *gnt_refs,
741 unsigned int nr_grefs,
744 struct xenbus_map_node *node = info->node;
745 struct vm_struct *area;
749 area = get_vm_area(XEN_PAGE_SIZE * nr_grefs, VM_IOREMAP);
752 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
753 XEN_PAGE_SIZE * nr_grefs, map_ring_apply, info))
755 err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
756 info, GNTMAP_host_map | GNTMAP_contains_pte,
761 node->nr_handles = nr_grefs;
762 node->pv.area = area;
764 spin_lock(&xenbus_valloc_lock);
765 list_add(&node->next, &xenbus_valloc_pages);
766 spin_unlock(&xenbus_valloc_lock);
777 pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs);
782 static int xenbus_unmap_ring_pv(struct xenbus_device *dev, void *vaddr)
784 struct xenbus_map_node *node;
785 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
791 spin_lock(&xenbus_valloc_lock);
792 list_for_each_entry(node, &xenbus_valloc_pages, next) {
793 if (node->pv.area->addr == vaddr) {
794 list_del(&node->next);
800 spin_unlock(&xenbus_valloc_lock);
803 xenbus_dev_error(dev, -ENOENT,
804 "can't find mapped virtual address %p", vaddr);
805 return GNTST_bad_virt_addr;
808 for (i = 0; i < node->nr_handles; i++) {
811 memset(&unmap[i], 0, sizeof(unmap[i]));
812 addr = (unsigned long)vaddr + (XEN_PAGE_SIZE * i);
813 unmap[i].host_addr = arbitrary_virt_to_machine(
814 lookup_address(addr, &level)).maddr;
815 unmap[i].dev_bus_addr = 0;
816 unmap[i].handle = node->handles[i];
819 BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i));
823 for (i = 0; i < node->nr_handles; i++) {
824 if (unmap[i].status != GNTST_okay) {
826 xenbus_dev_error(dev, unmap[i].status,
827 "unmapping page at handle %d error %d",
828 node->handles[i], unmap[i].status);
829 err = unmap[i].status;
835 free_vm_area(node->pv.area);
837 pr_alert("leaking VM area %p size %u page(s)",
838 node->pv.area, node->nr_handles);
844 static const struct xenbus_ring_ops ring_ops_pv = {
845 .map = xenbus_map_ring_pv,
846 .unmap = xenbus_unmap_ring_pv,
850 struct unmap_ring_hvm
853 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
856 static void xenbus_unmap_ring_setup_grant_hvm(unsigned long gfn,
857 unsigned int goffset,
861 struct unmap_ring_hvm *info = data;
863 info->addrs[info->idx] = (unsigned long)gfn_to_virt(gfn);
868 static int xenbus_unmap_ring_hvm(struct xenbus_device *dev, void *vaddr)
871 struct xenbus_map_node *node;
873 struct unmap_ring_hvm info = {
876 unsigned int nr_pages;
878 spin_lock(&xenbus_valloc_lock);
879 list_for_each_entry(node, &xenbus_valloc_pages, next) {
880 addr = node->hvm.addr;
882 list_del(&node->next);
888 spin_unlock(&xenbus_valloc_lock);
891 xenbus_dev_error(dev, -ENOENT,
892 "can't find mapped virtual address %p", vaddr);
893 return GNTST_bad_virt_addr;
896 nr_pages = XENBUS_PAGES(node->nr_handles);
898 gnttab_foreach_grant(node->hvm.pages, node->nr_handles,
899 xenbus_unmap_ring_setup_grant_hvm,
902 rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
906 xen_free_unpopulated_pages(nr_pages, node->hvm.pages);
909 WARN(1, "Leaking %p, size %u page(s)\n", vaddr, nr_pages);
916 * xenbus_read_driver_state
917 * @path: path for driver
919 * Return the state of the driver rooted at the given store path, or
920 * XenbusStateUnknown if no state can be read.
922 enum xenbus_state xenbus_read_driver_state(const char *path)
924 enum xenbus_state result;
925 int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
927 result = XenbusStateUnknown;
931 EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
933 static const struct xenbus_ring_ops ring_ops_hvm = {
934 .map = xenbus_map_ring_hvm,
935 .unmap = xenbus_unmap_ring_hvm,
938 void __init xenbus_ring_ops_init(void)
941 if (!xen_feature(XENFEAT_auto_translated_physmap))
942 ring_ops = &ring_ops_pv;
945 ring_ops = &ring_ops_hvm;