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 struct xenbus_map_node
{
53 struct list_head next
;
56 struct vm_struct
*area
;
59 struct page
*pages
[XENBUS_MAX_RING_PAGES
];
63 grant_handle_t handles
[XENBUS_MAX_RING_PAGES
];
64 unsigned int nr_handles
;
67 static DEFINE_SPINLOCK(xenbus_valloc_lock
);
68 static LIST_HEAD(xenbus_valloc_pages
);
70 struct xenbus_ring_ops
{
71 int (*map
)(struct xenbus_device
*dev
,
72 grant_ref_t
*gnt_refs
, unsigned int nr_grefs
,
74 int (*unmap
)(struct xenbus_device
*dev
, void *vaddr
);
77 static const struct xenbus_ring_ops
*ring_ops __read_mostly
;
79 const char *xenbus_strstate(enum xenbus_state state
)
81 static const char *const name
[] = {
82 [ XenbusStateUnknown
] = "Unknown",
83 [ XenbusStateInitialising
] = "Initialising",
84 [ XenbusStateInitWait
] = "InitWait",
85 [ XenbusStateInitialised
] = "Initialised",
86 [ XenbusStateConnected
] = "Connected",
87 [ XenbusStateClosing
] = "Closing",
88 [ XenbusStateClosed
] = "Closed",
89 [XenbusStateReconfiguring
] = "Reconfiguring",
90 [XenbusStateReconfigured
] = "Reconfigured",
92 return (state
< ARRAY_SIZE(name
)) ? name
[state
] : "INVALID";
94 EXPORT_SYMBOL_GPL(xenbus_strstate
);
97 * xenbus_watch_path - register a watch
99 * @path: path to watch
100 * @watch: watch to register
101 * @callback: callback to register
103 * Register a @watch on the given path, using the given xenbus_watch structure
104 * for storage, and the given @callback function as the callback. Return 0 on
105 * success, or -errno on error. On success, the given @path will be saved as
106 * @watch->node, and remains the caller's to free. On error, @watch->node will
107 * be NULL, the device will switch to %XenbusStateClosing, and the error will
108 * be saved in the store.
110 int xenbus_watch_path(struct xenbus_device
*dev
, const char *path
,
111 struct xenbus_watch
*watch
,
112 void (*callback
)(struct xenbus_watch
*,
113 const char **, unsigned int))
118 watch
->callback
= callback
;
120 err
= register_xenbus_watch(watch
);
124 watch
->callback
= NULL
;
125 xenbus_dev_fatal(dev
, err
, "adding watch on %s", path
);
130 EXPORT_SYMBOL_GPL(xenbus_watch_path
);
134 * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path
135 * @dev: xenbus device
136 * @watch: watch to register
137 * @callback: callback to register
138 * @pathfmt: format of path to watch
140 * Register a watch on the given @path, using the given xenbus_watch
141 * structure for storage, and the given @callback function as the callback.
142 * Return 0 on success, or -errno on error. On success, the watched path
143 * (@path/@path2) will be saved as @watch->node, and becomes the caller's to
144 * kfree(). On error, watch->node will be NULL, so the caller has nothing to
145 * free, the device will switch to %XenbusStateClosing, and the error will be
146 * saved in the store.
148 int xenbus_watch_pathfmt(struct xenbus_device
*dev
,
149 struct xenbus_watch
*watch
,
150 void (*callback
)(struct xenbus_watch
*,
151 const char **, unsigned int),
152 const char *pathfmt
, ...)
158 va_start(ap
, pathfmt
);
159 path
= kvasprintf(GFP_NOIO
| __GFP_HIGH
, pathfmt
, ap
);
163 xenbus_dev_fatal(dev
, -ENOMEM
, "allocating path for watch");
166 err
= xenbus_watch_path(dev
, path
, watch
, callback
);
172 EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt
);
174 static void xenbus_switch_fatal(struct xenbus_device
*, int, int,
178 __xenbus_switch_state(struct xenbus_device
*dev
,
179 enum xenbus_state state
, int depth
)
181 /* We check whether the state is currently set to the given value, and
182 if not, then the state is set. We don't want to unconditionally
183 write the given state, because we don't want to fire watches
184 unnecessarily. Furthermore, if the node has gone, we don't write
185 to it, as the device will be tearing down, and we don't want to
186 resurrect that directory.
188 Note that, because of this cached value of our state, this
189 function will not take a caller's Xenstore transaction
190 (something it was trying to in the past) because dev->state
191 would not get reset if the transaction was aborted.
194 struct xenbus_transaction xbt
;
198 if (state
== dev
->state
)
204 err
= xenbus_transaction_start(&xbt
);
206 xenbus_switch_fatal(dev
, depth
, err
, "starting transaction");
210 err
= xenbus_scanf(xbt
, dev
->nodename
, "state", "%d", ¤t_state
);
214 err
= xenbus_printf(xbt
, dev
->nodename
, "state", "%d", state
);
216 xenbus_switch_fatal(dev
, depth
, err
, "writing new state");
222 err
= xenbus_transaction_end(xbt
, abort
);
224 if (err
== -EAGAIN
&& !abort
)
226 xenbus_switch_fatal(dev
, depth
, err
, "ending transaction");
234 * xenbus_switch_state
235 * @dev: xenbus device
238 * Advertise in the store a change of the given driver to the given new_state.
239 * Return 0 on success, or -errno on error. On error, the device will switch
240 * to XenbusStateClosing, and the error will be saved in the store.
242 int xenbus_switch_state(struct xenbus_device
*dev
, enum xenbus_state state
)
244 return __xenbus_switch_state(dev
, state
, 0);
247 EXPORT_SYMBOL_GPL(xenbus_switch_state
);
249 int xenbus_frontend_closed(struct xenbus_device
*dev
)
251 xenbus_switch_state(dev
, XenbusStateClosed
);
252 complete(&dev
->down
);
255 EXPORT_SYMBOL_GPL(xenbus_frontend_closed
);
258 * Return the path to the error node for the given device, or NULL on failure.
259 * If the value returned is non-NULL, then it is the caller's to kfree.
261 static char *error_path(struct xenbus_device
*dev
)
263 return kasprintf(GFP_KERNEL
, "error/%s", dev
->nodename
);
267 static void xenbus_va_dev_error(struct xenbus_device
*dev
, int err
,
268 const char *fmt
, va_list ap
)
271 char *printf_buffer
= NULL
;
272 char *path_buffer
= NULL
;
274 #define PRINTF_BUFFER_SIZE 4096
275 printf_buffer
= kmalloc(PRINTF_BUFFER_SIZE
, GFP_KERNEL
);
276 if (printf_buffer
== NULL
)
279 len
= sprintf(printf_buffer
, "%i ", -err
);
280 vsnprintf(printf_buffer
+len
, PRINTF_BUFFER_SIZE
-len
, fmt
, ap
);
282 dev_err(&dev
->dev
, "%s\n", printf_buffer
);
284 path_buffer
= error_path(dev
);
286 if (path_buffer
== NULL
) {
287 dev_err(&dev
->dev
, "failed to write error node for %s (%s)\n",
288 dev
->nodename
, printf_buffer
);
292 if (xenbus_write(XBT_NIL
, path_buffer
, "error", printf_buffer
) != 0) {
293 dev_err(&dev
->dev
, "failed to write error node for %s (%s)\n",
294 dev
->nodename
, printf_buffer
);
299 kfree(printf_buffer
);
306 * @dev: xenbus device
307 * @err: error to report
308 * @fmt: error message format
310 * Report the given negative errno into the store, along with the given
313 void xenbus_dev_error(struct xenbus_device
*dev
, int err
, const char *fmt
, ...)
318 xenbus_va_dev_error(dev
, err
, fmt
, ap
);
321 EXPORT_SYMBOL_GPL(xenbus_dev_error
);
325 * @dev: xenbus device
326 * @err: error to report
327 * @fmt: error message format
329 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
330 * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
331 * closedown of this driver and its peer.
334 void xenbus_dev_fatal(struct xenbus_device
*dev
, int err
, const char *fmt
, ...)
339 xenbus_va_dev_error(dev
, err
, fmt
, ap
);
342 xenbus_switch_state(dev
, XenbusStateClosing
);
344 EXPORT_SYMBOL_GPL(xenbus_dev_fatal
);
347 * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps
348 * avoiding recursion within xenbus_switch_state.
350 static void xenbus_switch_fatal(struct xenbus_device
*dev
, int depth
, int err
,
351 const char *fmt
, ...)
356 xenbus_va_dev_error(dev
, err
, fmt
, ap
);
360 __xenbus_switch_state(dev
, XenbusStateClosing
, 1);
365 * @dev: xenbus device
366 * @vaddr: starting virtual address of the ring
367 * @nr_pages: number of pages to be granted
368 * @grefs: grant reference array to be filled in
370 * Grant access to the given @vaddr to the peer of the given device.
371 * Then fill in @grefs with grant references. Return 0 on success, or
372 * -errno on error. On error, the device will switch to
373 * XenbusStateClosing, and the error will be saved in the store.
375 int xenbus_grant_ring(struct xenbus_device
*dev
, void *vaddr
,
376 unsigned int nr_pages
, grant_ref_t
*grefs
)
381 for (i
= 0; i
< nr_pages
; i
++) {
382 err
= gnttab_grant_foreign_access(dev
->otherend_id
,
383 virt_to_mfn(vaddr
), 0);
385 xenbus_dev_fatal(dev
, err
,
386 "granting access to ring page");
391 vaddr
= vaddr
+ PAGE_SIZE
;
397 for (j
= 0; j
< i
; j
++)
398 gnttab_end_foreign_access_ref(grefs
[j
], 0);
401 EXPORT_SYMBOL_GPL(xenbus_grant_ring
);
405 * Allocate an event channel for the given xenbus_device, assigning the newly
406 * created local port to *port. Return 0 on success, or -errno on error. On
407 * error, the device will switch to XenbusStateClosing, and the error will be
408 * saved in the store.
410 int xenbus_alloc_evtchn(struct xenbus_device
*dev
, int *port
)
412 struct evtchn_alloc_unbound alloc_unbound
;
415 alloc_unbound
.dom
= DOMID_SELF
;
416 alloc_unbound
.remote_dom
= dev
->otherend_id
;
418 err
= HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound
,
421 xenbus_dev_fatal(dev
, err
, "allocating event channel");
423 *port
= alloc_unbound
.port
;
427 EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn
);
431 * Free an existing event channel. Returns 0 on success or -errno on error.
433 int xenbus_free_evtchn(struct xenbus_device
*dev
, int port
)
435 struct evtchn_close close
;
440 err
= HYPERVISOR_event_channel_op(EVTCHNOP_close
, &close
);
442 xenbus_dev_error(dev
, err
, "freeing event channel %d", port
);
446 EXPORT_SYMBOL_GPL(xenbus_free_evtchn
);
450 * xenbus_map_ring_valloc
451 * @dev: xenbus device
452 * @gnt_refs: grant reference array
453 * @nr_grefs: number of grant references
454 * @vaddr: pointer to address to be filled out by mapping
456 * Map @nr_grefs pages of memory into this domain from another
457 * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
458 * pages of virtual address space, maps the pages to that address, and
459 * sets *vaddr to that address. Returns 0 on success, and GNTST_*
460 * (see xen/include/interface/grant_table.h) or -ENOMEM / -EINVAL on
461 * error. If an error is returned, device will switch to
462 * XenbusStateClosing and the error message will be saved in XenStore.
464 int xenbus_map_ring_valloc(struct xenbus_device
*dev
, grant_ref_t
*gnt_refs
,
465 unsigned int nr_grefs
, void **vaddr
)
467 return ring_ops
->map(dev
, gnt_refs
, nr_grefs
, vaddr
);
469 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc
);
471 /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
472 * long), e.g. 32-on-64. Caller is responsible for preparing the
473 * right array to feed into this function */
474 static int __xenbus_map_ring(struct xenbus_device
*dev
,
475 grant_ref_t
*gnt_refs
,
476 unsigned int nr_grefs
,
477 grant_handle_t
*handles
,
482 struct gnttab_map_grant_ref map
[XENBUS_MAX_RING_PAGES
];
483 struct gnttab_unmap_grant_ref unmap
[XENBUS_MAX_RING_PAGES
];
485 int err
= GNTST_okay
;
487 if (nr_grefs
> XENBUS_MAX_RING_PAGES
)
490 for (i
= 0; i
< nr_grefs
; i
++) {
491 memset(&map
[i
], 0, sizeof(map
[i
]));
492 gnttab_set_map_op(&map
[i
], addrs
[i
], flags
, gnt_refs
[i
],
494 handles
[i
] = INVALID_GRANT_HANDLE
;
497 gnttab_batch_map(map
, i
);
499 for (i
= 0; i
< nr_grefs
; i
++) {
500 if (map
[i
].status
!= GNTST_okay
) {
502 xenbus_dev_fatal(dev
, map
[i
].status
,
503 "mapping in shared page %d from domain %d",
504 gnt_refs
[i
], dev
->otherend_id
);
507 handles
[i
] = map
[i
].handle
;
513 for (i
= j
= 0; i
< nr_grefs
; i
++) {
514 if (handles
[i
] != INVALID_GRANT_HANDLE
) {
515 memset(&unmap
[j
], 0, sizeof(unmap
[j
]));
516 gnttab_set_unmap_op(&unmap
[j
], (phys_addr_t
)addrs
[i
],
517 GNTMAP_host_map
, handles
[i
]);
522 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref
, unmap
, j
))
526 for (i
= 0; i
< j
; i
++) {
527 if (unmap
[i
].status
!= GNTST_okay
) {
536 static int xenbus_map_ring_valloc_pv(struct xenbus_device
*dev
,
537 grant_ref_t
*gnt_refs
,
538 unsigned int nr_grefs
,
541 struct xenbus_map_node
*node
;
542 struct vm_struct
*area
;
543 pte_t
*ptes
[XENBUS_MAX_RING_PAGES
];
544 phys_addr_t phys_addrs
[XENBUS_MAX_RING_PAGES
];
545 int err
= GNTST_okay
;
551 if (nr_grefs
> XENBUS_MAX_RING_PAGES
)
554 node
= kzalloc(sizeof(*node
), GFP_KERNEL
);
558 area
= alloc_vm_area(PAGE_SIZE
* nr_grefs
, ptes
);
564 for (i
= 0; i
< nr_grefs
; i
++)
565 phys_addrs
[i
] = arbitrary_virt_to_machine(ptes
[i
]).maddr
;
567 err
= __xenbus_map_ring(dev
, gnt_refs
, nr_grefs
, node
->handles
,
569 GNTMAP_host_map
| GNTMAP_contains_pte
,
574 node
->nr_handles
= nr_grefs
;
575 node
->pv
.area
= area
;
577 spin_lock(&xenbus_valloc_lock
);
578 list_add(&node
->next
, &xenbus_valloc_pages
);
579 spin_unlock(&xenbus_valloc_lock
);
588 pr_alert("leaking VM area %p size %u page(s)", area
, nr_grefs
);
594 static int xenbus_map_ring_valloc_hvm(struct xenbus_device
*dev
,
595 grant_ref_t
*gnt_ref
,
596 unsigned int nr_grefs
,
599 struct xenbus_map_node
*node
;
604 /* Why do we need two arrays? See comment of __xenbus_map_ring */
605 phys_addr_t phys_addrs
[XENBUS_MAX_RING_PAGES
];
606 unsigned long addrs
[XENBUS_MAX_RING_PAGES
];
608 if (nr_grefs
> XENBUS_MAX_RING_PAGES
)
613 node
= kzalloc(sizeof(*node
), GFP_KERNEL
);
617 err
= alloc_xenballooned_pages(nr_grefs
, node
->hvm
.pages
,
622 for (i
= 0; i
< nr_grefs
; i
++) {
623 unsigned long pfn
= page_to_pfn(node
->hvm
.pages
[i
]);
624 phys_addrs
[i
] = (unsigned long)pfn_to_kaddr(pfn
);
625 addrs
[i
] = (unsigned long)pfn_to_kaddr(pfn
);
628 err
= __xenbus_map_ring(dev
, gnt_ref
, nr_grefs
, node
->handles
,
629 phys_addrs
, GNTMAP_host_map
, &leaked
);
630 node
->nr_handles
= nr_grefs
;
633 goto out_free_ballooned_pages
;
635 addr
= vmap(node
->hvm
.pages
, nr_grefs
, VM_MAP
| VM_IOREMAP
,
639 goto out_xenbus_unmap_ring
;
642 node
->hvm
.addr
= addr
;
644 spin_lock(&xenbus_valloc_lock
);
645 list_add(&node
->next
, &xenbus_valloc_pages
);
646 spin_unlock(&xenbus_valloc_lock
);
651 out_xenbus_unmap_ring
:
653 xenbus_unmap_ring(dev
, node
->handles
, node
->nr_handles
,
656 pr_alert("leaking %p size %u page(s)",
658 out_free_ballooned_pages
:
660 free_xenballooned_pages(nr_grefs
, node
->hvm
.pages
);
669 * @dev: xenbus device
670 * @gnt_refs: grant reference array
671 * @nr_grefs: number of grant reference
672 * @handles: pointer to grant handle to be filled
673 * @vaddrs: addresses to be mapped to
674 * @leaked: fail to clean up a failed map, caller should not free vaddr
676 * Map pages of memory into this domain from another domain's grant table.
677 * xenbus_map_ring does not allocate the virtual address space (you must do
678 * this yourself!). It only maps in the pages to the specified address.
679 * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
680 * or -ENOMEM / -EINVAL on error. If an error is returned, device will switch to
681 * XenbusStateClosing and the first error message will be saved in XenStore.
682 * Further more if we fail to map the ring, caller should check @leaked.
683 * If @leaked is not zero it means xenbus_map_ring fails to clean up, caller
684 * should not free the address space of @vaddr.
686 int xenbus_map_ring(struct xenbus_device
*dev
, grant_ref_t
*gnt_refs
,
687 unsigned int nr_grefs
, grant_handle_t
*handles
,
688 unsigned long *vaddrs
, bool *leaked
)
690 phys_addr_t phys_addrs
[XENBUS_MAX_RING_PAGES
];
693 if (nr_grefs
> XENBUS_MAX_RING_PAGES
)
696 for (i
= 0; i
< nr_grefs
; i
++)
697 phys_addrs
[i
] = (unsigned long)vaddrs
[i
];
699 return __xenbus_map_ring(dev
, gnt_refs
, nr_grefs
, handles
,
700 phys_addrs
, GNTMAP_host_map
, leaked
);
702 EXPORT_SYMBOL_GPL(xenbus_map_ring
);
706 * xenbus_unmap_ring_vfree
707 * @dev: xenbus device
708 * @vaddr: addr to unmap
710 * Based on Rusty Russell's skeleton driver's unmap_page.
711 * Unmap a page of memory in this domain that was imported from another domain.
712 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
713 * xenbus_map_ring_valloc (it will free the virtual address space).
714 * Returns 0 on success and returns GNTST_* on error
715 * (see xen/include/interface/grant_table.h).
717 int xenbus_unmap_ring_vfree(struct xenbus_device
*dev
, void *vaddr
)
719 return ring_ops
->unmap(dev
, vaddr
);
721 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree
);
723 static int xenbus_unmap_ring_vfree_pv(struct xenbus_device
*dev
, void *vaddr
)
725 struct xenbus_map_node
*node
;
726 struct gnttab_unmap_grant_ref unmap
[XENBUS_MAX_RING_PAGES
];
732 spin_lock(&xenbus_valloc_lock
);
733 list_for_each_entry(node
, &xenbus_valloc_pages
, next
) {
734 if (node
->pv
.area
->addr
== vaddr
) {
735 list_del(&node
->next
);
741 spin_unlock(&xenbus_valloc_lock
);
744 xenbus_dev_error(dev
, -ENOENT
,
745 "can't find mapped virtual address %p", vaddr
);
746 return GNTST_bad_virt_addr
;
749 for (i
= 0; i
< node
->nr_handles
; i
++) {
752 memset(&unmap
[i
], 0, sizeof(unmap
[i
]));
753 addr
= (unsigned long)vaddr
+ (PAGE_SIZE
* i
);
754 unmap
[i
].host_addr
= arbitrary_virt_to_machine(
755 lookup_address(addr
, &level
)).maddr
;
756 unmap
[i
].dev_bus_addr
= 0;
757 unmap
[i
].handle
= node
->handles
[i
];
760 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref
, unmap
, i
))
765 for (i
= 0; i
< node
->nr_handles
; i
++) {
766 if (unmap
[i
].status
!= GNTST_okay
) {
768 xenbus_dev_error(dev
, unmap
[i
].status
,
769 "unmapping page at handle %d error %d",
770 node
->handles
[i
], unmap
[i
].status
);
771 err
= unmap
[i
].status
;
777 free_vm_area(node
->pv
.area
);
779 pr_alert("leaking VM area %p size %u page(s)",
780 node
->pv
.area
, node
->nr_handles
);
786 static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device
*dev
, void *vaddr
)
789 struct xenbus_map_node
*node
;
791 unsigned long addrs
[XENBUS_MAX_RING_PAGES
];
794 spin_lock(&xenbus_valloc_lock
);
795 list_for_each_entry(node
, &xenbus_valloc_pages
, next
) {
796 addr
= node
->hvm
.addr
;
798 list_del(&node
->next
);
804 spin_unlock(&xenbus_valloc_lock
);
807 xenbus_dev_error(dev
, -ENOENT
,
808 "can't find mapped virtual address %p", vaddr
);
809 return GNTST_bad_virt_addr
;
812 for (i
= 0; i
< node
->nr_handles
; i
++)
813 addrs
[i
] = (unsigned long)pfn_to_kaddr(page_to_pfn(node
->hvm
.pages
[i
]));
815 rv
= xenbus_unmap_ring(dev
, node
->handles
, node
->nr_handles
,
819 free_xenballooned_pages(node
->nr_handles
, node
->hvm
.pages
);
822 WARN(1, "Leaking %p, size %u page(s)\n", vaddr
,
831 * @dev: xenbus device
832 * @handles: grant handle array
833 * @nr_handles: number of handles in the array
834 * @vaddrs: addresses to unmap
836 * Unmap memory in this domain that was imported from another domain.
837 * Returns 0 on success and returns GNTST_* on error
838 * (see xen/include/interface/grant_table.h).
840 int xenbus_unmap_ring(struct xenbus_device
*dev
,
841 grant_handle_t
*handles
, unsigned int nr_handles
,
842 unsigned long *vaddrs
)
844 struct gnttab_unmap_grant_ref unmap
[XENBUS_MAX_RING_PAGES
];
848 if (nr_handles
> XENBUS_MAX_RING_PAGES
)
851 for (i
= 0; i
< nr_handles
; i
++)
852 gnttab_set_unmap_op(&unmap
[i
], vaddrs
[i
],
853 GNTMAP_host_map
, handles
[i
]);
855 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref
, unmap
, i
))
859 for (i
= 0; i
< nr_handles
; i
++) {
860 if (unmap
[i
].status
!= GNTST_okay
) {
861 xenbus_dev_error(dev
, unmap
[i
].status
,
862 "unmapping page at handle %d error %d",
863 handles
[i
], unmap
[i
].status
);
864 err
= unmap
[i
].status
;
871 EXPORT_SYMBOL_GPL(xenbus_unmap_ring
);
875 * xenbus_read_driver_state
876 * @path: path for driver
878 * Return the state of the driver rooted at the given store path, or
879 * XenbusStateUnknown if no state can be read.
881 enum xenbus_state
xenbus_read_driver_state(const char *path
)
883 enum xenbus_state result
;
884 int err
= xenbus_gather(XBT_NIL
, path
, "state", "%d", &result
, NULL
);
886 result
= XenbusStateUnknown
;
890 EXPORT_SYMBOL_GPL(xenbus_read_driver_state
);
892 static const struct xenbus_ring_ops ring_ops_pv
= {
893 .map
= xenbus_map_ring_valloc_pv
,
894 .unmap
= xenbus_unmap_ring_vfree_pv
,
897 static const struct xenbus_ring_ops ring_ops_hvm
= {
898 .map
= xenbus_map_ring_valloc_hvm
,
899 .unmap
= xenbus_unmap_ring_vfree_hvm
,
902 void __init
xenbus_ring_ops_init(void)
904 if (!xen_feature(XENFEAT_auto_translated_physmap
))
905 ring_ops
= &ring_ops_pv
;
907 ring_ops
= &ring_ops_hvm
;