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>
50 #include "xenbus_probe.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 static DEFINE_SPINLOCK(xenbus_valloc_lock);
73 static LIST_HEAD(xenbus_valloc_pages);
75 struct xenbus_ring_ops {
76 int (*map)(struct xenbus_device *dev,
77 grant_ref_t *gnt_refs, unsigned int nr_grefs,
79 int (*unmap)(struct xenbus_device *dev, void *vaddr);
82 static const struct xenbus_ring_ops *ring_ops __read_mostly;
84 const char *xenbus_strstate(enum xenbus_state state)
86 static const char *const name[] = {
87 [ XenbusStateUnknown ] = "Unknown",
88 [ XenbusStateInitialising ] = "Initialising",
89 [ XenbusStateInitWait ] = "InitWait",
90 [ XenbusStateInitialised ] = "Initialised",
91 [ XenbusStateConnected ] = "Connected",
92 [ XenbusStateClosing ] = "Closing",
93 [ XenbusStateClosed ] = "Closed",
94 [XenbusStateReconfiguring] = "Reconfiguring",
95 [XenbusStateReconfigured] = "Reconfigured",
97 return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID";
99 EXPORT_SYMBOL_GPL(xenbus_strstate);
102 * xenbus_watch_path - register a watch
103 * @dev: xenbus device
104 * @path: path to watch
105 * @watch: watch to register
106 * @callback: callback to register
108 * Register a @watch on the given path, using the given xenbus_watch structure
109 * for storage, and the given @callback function as the callback. Return 0 on
110 * success, or -errno on error. On success, the given @path will be saved as
111 * @watch->node, and remains the caller's to free. On error, @watch->node will
112 * be NULL, the device will switch to %XenbusStateClosing, and the error will
113 * be saved in the store.
115 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
116 struct xenbus_watch *watch,
117 bool (*will_handle)(struct xenbus_watch *,
118 const char **, unsigned int),
119 void (*callback)(struct xenbus_watch *,
120 const char **, unsigned int))
125 watch->will_handle = will_handle;
126 watch->callback = callback;
128 err = register_xenbus_watch(watch);
132 watch->will_handle = NULL;
133 watch->callback = NULL;
134 xenbus_dev_fatal(dev, err, "adding watch on %s", path);
139 EXPORT_SYMBOL_GPL(xenbus_watch_path);
143 * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path
144 * @dev: xenbus device
145 * @watch: watch to register
146 * @callback: callback to register
147 * @pathfmt: format of path to watch
149 * Register a watch on the given @path, using the given xenbus_watch
150 * structure for storage, and the given @callback function as the callback.
151 * Return 0 on success, or -errno on error. On success, the watched path
152 * (@path/@path2) will be saved as @watch->node, and becomes the caller's to
153 * kfree(). On error, watch->node will be NULL, so the caller has nothing to
154 * free, the device will switch to %XenbusStateClosing, and the error will be
155 * saved in the store.
157 int xenbus_watch_pathfmt(struct xenbus_device *dev,
158 struct xenbus_watch *watch,
159 bool (*will_handle)(struct xenbus_watch *,
160 const char **, unsigned int),
161 void (*callback)(struct xenbus_watch *,
162 const char **, unsigned int),
163 const char *pathfmt, ...)
169 va_start(ap, pathfmt);
170 path = kvasprintf(GFP_NOIO | __GFP_HIGH, pathfmt, ap);
174 xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
177 err = xenbus_watch_path(dev, path, watch, will_handle, callback);
183 EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt);
185 static void xenbus_switch_fatal(struct xenbus_device *, int, int,
189 __xenbus_switch_state(struct xenbus_device *dev,
190 enum xenbus_state state, int depth)
192 /* We check whether the state is currently set to the given value, and
193 if not, then the state is set. We don't want to unconditionally
194 write the given state, because we don't want to fire watches
195 unnecessarily. Furthermore, if the node has gone, we don't write
196 to it, as the device will be tearing down, and we don't want to
197 resurrect that directory.
199 Note that, because of this cached value of our state, this
200 function will not take a caller's Xenstore transaction
201 (something it was trying to in the past) because dev->state
202 would not get reset if the transaction was aborted.
205 struct xenbus_transaction xbt;
209 if (state == dev->state)
215 err = xenbus_transaction_start(&xbt);
217 xenbus_switch_fatal(dev, depth, err, "starting transaction");
221 err = xenbus_scanf(xbt, dev->nodename, "state", "%d", ¤t_state);
225 err = xenbus_printf(xbt, dev->nodename, "state", "%d", state);
227 xenbus_switch_fatal(dev, depth, err, "writing new state");
233 err = xenbus_transaction_end(xbt, abort);
235 if (err == -EAGAIN && !abort)
237 xenbus_switch_fatal(dev, depth, err, "ending transaction");
245 * xenbus_switch_state
246 * @dev: xenbus device
249 * Advertise in the store a change of the given driver to the given new_state.
250 * Return 0 on success, or -errno on error. On error, the device will switch
251 * to XenbusStateClosing, and the error will be saved in the store.
253 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state state)
255 return __xenbus_switch_state(dev, state, 0);
258 EXPORT_SYMBOL_GPL(xenbus_switch_state);
260 int xenbus_frontend_closed(struct xenbus_device *dev)
262 xenbus_switch_state(dev, XenbusStateClosed);
263 complete(&dev->down);
266 EXPORT_SYMBOL_GPL(xenbus_frontend_closed);
269 * Return the path to the error node for the given device, or NULL on failure.
270 * If the value returned is non-NULL, then it is the caller's to kfree.
272 static char *error_path(struct xenbus_device *dev)
274 return kasprintf(GFP_KERNEL, "error/%s", dev->nodename);
278 static void xenbus_va_dev_error(struct xenbus_device *dev, int err,
279 const char *fmt, va_list ap)
282 char *printf_buffer = NULL;
283 char *path_buffer = NULL;
285 #define PRINTF_BUFFER_SIZE 4096
286 printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL);
287 if (printf_buffer == NULL)
290 len = sprintf(printf_buffer, "%i ", -err);
291 vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap);
293 dev_err(&dev->dev, "%s\n", printf_buffer);
295 path_buffer = error_path(dev);
297 if (path_buffer == NULL) {
298 dev_err(&dev->dev, "failed to write error node for %s (%s)\n",
299 dev->nodename, printf_buffer);
303 if (xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer) != 0) {
304 dev_err(&dev->dev, "failed to write error node for %s (%s)\n",
305 dev->nodename, printf_buffer);
310 kfree(printf_buffer);
317 * @dev: xenbus device
318 * @err: error to report
319 * @fmt: error message format
321 * Report the given negative errno into the store, along with the given
324 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...)
329 xenbus_va_dev_error(dev, err, fmt, ap);
332 EXPORT_SYMBOL_GPL(xenbus_dev_error);
336 * @dev: xenbus device
337 * @err: error to report
338 * @fmt: error message format
340 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
341 * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
342 * closedown of this driver and its peer.
345 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...)
350 xenbus_va_dev_error(dev, err, fmt, ap);
353 xenbus_switch_state(dev, XenbusStateClosing);
355 EXPORT_SYMBOL_GPL(xenbus_dev_fatal);
358 * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps
359 * avoiding recursion within xenbus_switch_state.
361 static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err,
362 const char *fmt, ...)
367 xenbus_va_dev_error(dev, err, fmt, ap);
371 __xenbus_switch_state(dev, XenbusStateClosing, 1);
376 * @dev: xenbus device
377 * @vaddr: starting virtual address of the ring
378 * @nr_pages: number of pages to be granted
379 * @grefs: grant reference array to be filled in
381 * Grant access to the given @vaddr to the peer of the given device.
382 * Then fill in @grefs with grant references. Return 0 on success, or
383 * -errno on error. On error, the device will switch to
384 * XenbusStateClosing, and the error will be saved in the store.
386 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
387 unsigned int nr_pages, grant_ref_t *grefs)
391 grant_ref_t gref_head;
393 err = gnttab_alloc_grant_references(nr_pages, &gref_head);
395 xenbus_dev_fatal(dev, err, "granting access to ring page");
399 for (i = 0; i < nr_pages; i++) {
402 if (is_vmalloc_addr(vaddr))
403 gfn = pfn_to_gfn(vmalloc_to_pfn(vaddr));
405 gfn = virt_to_gfn(vaddr);
407 grefs[i] = gnttab_claim_grant_reference(&gref_head);
408 gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id,
411 vaddr = vaddr + XEN_PAGE_SIZE;
416 EXPORT_SYMBOL_GPL(xenbus_grant_ring);
420 * Allocate an event channel for the given xenbus_device, assigning the newly
421 * created local port to *port. Return 0 on success, or -errno on error. On
422 * error, the device will switch to XenbusStateClosing, and the error will be
423 * saved in the store.
425 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port)
427 struct evtchn_alloc_unbound alloc_unbound;
430 alloc_unbound.dom = DOMID_SELF;
431 alloc_unbound.remote_dom = dev->otherend_id;
433 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
436 xenbus_dev_fatal(dev, err, "allocating event channel");
438 *port = alloc_unbound.port;
442 EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
446 * Free an existing event channel. Returns 0 on success or -errno on error.
448 int xenbus_free_evtchn(struct xenbus_device *dev, int port)
450 struct evtchn_close close;
455 err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
457 xenbus_dev_error(dev, err, "freeing event channel %d", port);
461 EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
465 * xenbus_map_ring_valloc
466 * @dev: xenbus device
467 * @gnt_refs: grant reference array
468 * @nr_grefs: number of grant references
469 * @vaddr: pointer to address to be filled out by mapping
471 * Map @nr_grefs pages of memory into this domain from another
472 * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
473 * pages of virtual address space, maps the pages to that address, and
474 * sets *vaddr to that address. Returns 0 on success, and GNTST_*
475 * (see xen/include/interface/grant_table.h) or -ENOMEM / -EINVAL on
476 * error. If an error is returned, device will switch to
477 * XenbusStateClosing and the error message will be saved in XenStore.
479 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
480 unsigned int nr_grefs, void **vaddr)
484 err = ring_ops->map(dev, gnt_refs, nr_grefs, vaddr);
485 /* Some hypervisors are buggy and can return 1. */
487 err = GNTST_general_error;
491 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
493 /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
494 * long), e.g. 32-on-64. Caller is responsible for preparing the
495 * right array to feed into this function */
496 static int __xenbus_map_ring(struct xenbus_device *dev,
497 grant_ref_t *gnt_refs,
498 unsigned int nr_grefs,
499 grant_handle_t *handles,
504 struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS];
505 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
507 int err = GNTST_okay;
509 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
512 for (i = 0; i < nr_grefs; i++) {
513 memset(&map[i], 0, sizeof(map[i]));
514 gnttab_set_map_op(&map[i], addrs[i], flags, gnt_refs[i],
516 handles[i] = INVALID_GRANT_HANDLE;
519 gnttab_batch_map(map, i);
521 for (i = 0; i < nr_grefs; i++) {
522 if (map[i].status != GNTST_okay) {
524 xenbus_dev_fatal(dev, map[i].status,
525 "mapping in shared page %d from domain %d",
526 gnt_refs[i], dev->otherend_id);
529 handles[i] = map[i].handle;
535 for (i = j = 0; i < nr_grefs; i++) {
536 if (handles[i] != INVALID_GRANT_HANDLE) {
537 memset(&unmap[j], 0, sizeof(unmap[j]));
538 gnttab_set_unmap_op(&unmap[j], (phys_addr_t)addrs[i],
539 GNTMAP_host_map, handles[i]);
544 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, j))
548 for (i = 0; i < j; i++) {
549 if (unmap[i].status != GNTST_okay) {
558 static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
559 grant_ref_t *gnt_refs,
560 unsigned int nr_grefs,
563 struct xenbus_map_node *node;
564 struct vm_struct *area;
565 pte_t *ptes[XENBUS_MAX_RING_GRANTS];
566 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
567 int err = GNTST_okay;
573 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
576 node = kzalloc(sizeof(*node), GFP_KERNEL);
580 area = alloc_vm_area(XEN_PAGE_SIZE * nr_grefs, ptes);
586 for (i = 0; i < nr_grefs; i++)
587 phys_addrs[i] = arbitrary_virt_to_machine(ptes[i]).maddr;
589 err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
591 GNTMAP_host_map | GNTMAP_contains_pte,
596 node->nr_handles = nr_grefs;
597 node->pv.area = area;
599 spin_lock(&xenbus_valloc_lock);
600 list_add(&node->next, &xenbus_valloc_pages);
601 spin_unlock(&xenbus_valloc_lock);
610 pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs);
616 struct map_ring_valloc_hvm
620 /* Why do we need two arrays? See comment of __xenbus_map_ring */
621 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
622 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
625 static void xenbus_map_ring_setup_grant_hvm(unsigned long gfn,
626 unsigned int goffset,
630 struct map_ring_valloc_hvm *info = data;
631 unsigned long vaddr = (unsigned long)gfn_to_virt(gfn);
633 info->phys_addrs[info->idx] = vaddr;
634 info->addrs[info->idx] = vaddr;
639 static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
640 grant_ref_t *gnt_ref,
641 unsigned int nr_grefs,
644 struct xenbus_map_node *node;
648 struct map_ring_valloc_hvm info = {
651 unsigned int nr_pages = XENBUS_PAGES(nr_grefs);
653 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
658 node = kzalloc(sizeof(*node), GFP_KERNEL);
662 err = alloc_xenballooned_pages(nr_pages, node->hvm.pages);
666 gnttab_foreach_grant(node->hvm.pages, nr_grefs,
667 xenbus_map_ring_setup_grant_hvm,
670 err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles,
671 info.phys_addrs, GNTMAP_host_map, &leaked);
672 node->nr_handles = nr_grefs;
675 goto out_free_ballooned_pages;
677 addr = vmap(node->hvm.pages, nr_pages, VM_MAP | VM_IOREMAP,
681 goto out_xenbus_unmap_ring;
684 node->hvm.addr = addr;
686 spin_lock(&xenbus_valloc_lock);
687 list_add(&node->next, &xenbus_valloc_pages);
688 spin_unlock(&xenbus_valloc_lock);
693 out_xenbus_unmap_ring:
695 xenbus_unmap_ring(dev, node->handles, nr_grefs, info.addrs);
697 pr_alert("leaking %p size %u page(s)",
699 out_free_ballooned_pages:
701 free_xenballooned_pages(nr_pages, node->hvm.pages);
710 * @dev: xenbus device
711 * @gnt_refs: grant reference array
712 * @nr_grefs: number of grant reference
713 * @handles: pointer to grant handle to be filled
714 * @vaddrs: addresses to be mapped to
715 * @leaked: fail to clean up a failed map, caller should not free vaddr
717 * Map pages of memory into this domain from another domain's grant table.
718 * xenbus_map_ring does not allocate the virtual address space (you must do
719 * this yourself!). It only maps in the pages to the specified address.
720 * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
721 * or -ENOMEM / -EINVAL on error. If an error is returned, device will switch to
722 * XenbusStateClosing and the first error message will be saved in XenStore.
723 * Further more if we fail to map the ring, caller should check @leaked.
724 * If @leaked is not zero it means xenbus_map_ring fails to clean up, caller
725 * should not free the address space of @vaddr.
727 int xenbus_map_ring(struct xenbus_device *dev, grant_ref_t *gnt_refs,
728 unsigned int nr_grefs, grant_handle_t *handles,
729 unsigned long *vaddrs, bool *leaked)
731 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
734 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
737 for (i = 0; i < nr_grefs; i++)
738 phys_addrs[i] = (unsigned long)vaddrs[i];
740 return __xenbus_map_ring(dev, gnt_refs, nr_grefs, handles,
741 phys_addrs, GNTMAP_host_map, leaked);
743 EXPORT_SYMBOL_GPL(xenbus_map_ring);
747 * xenbus_unmap_ring_vfree
748 * @dev: xenbus device
749 * @vaddr: addr to unmap
751 * Based on Rusty Russell's skeleton driver's unmap_page.
752 * Unmap a page of memory in this domain that was imported from another domain.
753 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
754 * xenbus_map_ring_valloc (it will free the virtual address space).
755 * Returns 0 on success and returns GNTST_* on error
756 * (see xen/include/interface/grant_table.h).
758 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
760 return ring_ops->unmap(dev, vaddr);
762 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
764 static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
766 struct xenbus_map_node *node;
767 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
773 spin_lock(&xenbus_valloc_lock);
774 list_for_each_entry(node, &xenbus_valloc_pages, next) {
775 if (node->pv.area->addr == vaddr) {
776 list_del(&node->next);
782 spin_unlock(&xenbus_valloc_lock);
785 xenbus_dev_error(dev, -ENOENT,
786 "can't find mapped virtual address %p", vaddr);
787 return GNTST_bad_virt_addr;
790 for (i = 0; i < node->nr_handles; i++) {
793 memset(&unmap[i], 0, sizeof(unmap[i]));
794 addr = (unsigned long)vaddr + (XEN_PAGE_SIZE * i);
795 unmap[i].host_addr = arbitrary_virt_to_machine(
796 lookup_address(addr, &level)).maddr;
797 unmap[i].dev_bus_addr = 0;
798 unmap[i].handle = node->handles[i];
801 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
806 for (i = 0; i < node->nr_handles; i++) {
807 if (unmap[i].status != GNTST_okay) {
809 xenbus_dev_error(dev, unmap[i].status,
810 "unmapping page at handle %d error %d",
811 node->handles[i], unmap[i].status);
812 err = unmap[i].status;
818 free_vm_area(node->pv.area);
820 pr_alert("leaking VM area %p size %u page(s)",
821 node->pv.area, node->nr_handles);
827 struct unmap_ring_vfree_hvm
830 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
833 static void xenbus_unmap_ring_setup_grant_hvm(unsigned long gfn,
834 unsigned int goffset,
838 struct unmap_ring_vfree_hvm *info = data;
840 info->addrs[info->idx] = (unsigned long)gfn_to_virt(gfn);
845 static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
848 struct xenbus_map_node *node;
850 struct unmap_ring_vfree_hvm info = {
853 unsigned int nr_pages;
855 spin_lock(&xenbus_valloc_lock);
856 list_for_each_entry(node, &xenbus_valloc_pages, next) {
857 addr = node->hvm.addr;
859 list_del(&node->next);
865 spin_unlock(&xenbus_valloc_lock);
868 xenbus_dev_error(dev, -ENOENT,
869 "can't find mapped virtual address %p", vaddr);
870 return GNTST_bad_virt_addr;
873 nr_pages = XENBUS_PAGES(node->nr_handles);
875 gnttab_foreach_grant(node->hvm.pages, node->nr_handles,
876 xenbus_unmap_ring_setup_grant_hvm,
879 rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
883 free_xenballooned_pages(nr_pages, node->hvm.pages);
886 WARN(1, "Leaking %p, size %u page(s)\n", vaddr, nr_pages);
894 * @dev: xenbus device
895 * @handles: grant handle array
896 * @nr_handles: number of handles in the array
897 * @vaddrs: addresses to unmap
899 * Unmap memory in this domain that was imported from another domain.
900 * Returns 0 on success and returns GNTST_* on error
901 * (see xen/include/interface/grant_table.h).
903 int xenbus_unmap_ring(struct xenbus_device *dev,
904 grant_handle_t *handles, unsigned int nr_handles,
905 unsigned long *vaddrs)
907 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
911 if (nr_handles > XENBUS_MAX_RING_GRANTS)
914 for (i = 0; i < nr_handles; i++)
915 gnttab_set_unmap_op(&unmap[i], vaddrs[i],
916 GNTMAP_host_map, handles[i]);
918 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
922 for (i = 0; i < nr_handles; i++) {
923 if (unmap[i].status != GNTST_okay) {
924 xenbus_dev_error(dev, unmap[i].status,
925 "unmapping page at handle %d error %d",
926 handles[i], unmap[i].status);
927 err = unmap[i].status;
934 EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
938 * xenbus_read_driver_state
939 * @path: path for driver
941 * Return the state of the driver rooted at the given store path, or
942 * XenbusStateUnknown if no state can be read.
944 enum xenbus_state xenbus_read_driver_state(const char *path)
946 enum xenbus_state result;
947 int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
949 result = XenbusStateUnknown;
953 EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
955 static const struct xenbus_ring_ops ring_ops_pv = {
956 .map = xenbus_map_ring_valloc_pv,
957 .unmap = xenbus_unmap_ring_vfree_pv,
960 static const struct xenbus_ring_ops ring_ops_hvm = {
961 .map = xenbus_map_ring_valloc_hvm,
962 .unmap = xenbus_unmap_ring_vfree_hvm,
965 void __init xenbus_ring_ops_init(void)
967 if (!xen_feature(XENFEAT_auto_translated_physmap))
968 ring_ops = &ring_ops_pv;
970 ring_ops = &ring_ops_hvm;