xref: /freebsd/sys/xen/gnttab.h (revision 29fc4075e69fd27de0cded313ac6000165d99f8b)
1 /******************************************************************************
2  * gnttab.h
3  *
4  * Two sets of functionality:
5  * 1. Granting foreign access to our memory reservation.
6  * 2. Accessing others' memory reservations via grant references.
7  * (i.e., mechanisms for both sender and recipient of grant references)
8  *
9  * Copyright (c) 2004-2005, K A Fraser
10  * Copyright (c) 2005, Christopher Clark
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License version 2
14  * as published by the Free Software Foundation; or, when distributed
15  * separately from the Linux kernel or incorporated into other
16  * software packages, subject to the following license:
17  *
18  * Permission is hereby granted, free of charge, to any person obtaining a copy
19  * of this source file (the "Software"), to deal in the Software without
20  * restriction, including without limitation the rights to use, copy, modify,
21  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
22  * and to permit persons to whom the Software is furnished to do so, subject to
23  * the following conditions:
24  *
25  * The above copyright notice and this permission notice shall be included in
26  * all copies or substantial portions of the Software.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
31  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
32  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
33  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
34  * IN THE SOFTWARE.
35  */
36 
37 #ifndef __ASM_GNTTAB_H__
38 #define __ASM_GNTTAB_H__
39 
40 #include <xen/xen-os.h>
41 #include <xen/hypervisor.h>
42 #include <xen/features.h>
43 
44 #include <contrib/xen/grant_table.h>
45 
46 #define GNTTAB_LIST_END GRANT_REF_INVALID
47 
48 struct gnttab_free_callback {
49 	struct gnttab_free_callback *next;
50 	void (*fn)(void *);
51 	void *arg;
52 	uint16_t count;
53 };
54 
55 /*
56  * Allocate a grant table reference and return it in *result. Returns
57  * zero on success or errno on error.
58  */
59 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
60     int flags, grant_ref_t *result);
61 
62 /*
63  * End access through the given grant reference, iff the grant entry is no
64  * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
65  * use.
66  */
67 int gnttab_end_foreign_access_ref(grant_ref_t ref);
68 
69 /*
70  * Eventually end access through the given grant reference, and once that
71  * access has been ended, free the given page too.  Access will be ended
72  * immediately iff the grant entry is not in use, otherwise it will happen
73  * some time later.  page may be 0, in which case no freeing will occur.
74  */
75 void gnttab_end_foreign_access(grant_ref_t ref, void *page);
76 
77 /*
78  * Eventually end access through the given array of grant references.
79  * Access will be ended immediately iff the grant entry is not in use,
80  * otherwise it will happen some time later
81  */
82 void gnttab_end_foreign_access_references(u_int count, grant_ref_t *refs);
83 
84 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn, grant_ref_t *result);
85 
86 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
87 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
88 
89 int gnttab_query_foreign_access(grant_ref_t ref);
90 
91 /*
92  * operations on reserved batches of grant references
93  */
94 int gnttab_alloc_grant_references(uint16_t count, grant_ref_t *pprivate_head);
95 
96 void gnttab_free_grant_reference(grant_ref_t ref);
97 
98 void gnttab_free_grant_references(grant_ref_t head);
99 
100 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
101 
102 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
103 
104 void gnttab_release_grant_reference(grant_ref_t *private_head,
105 				    grant_ref_t release);
106 
107 void gnttab_request_free_callback(struct gnttab_free_callback *callback,
108 				  void (*fn)(void *), void *arg, uint16_t count);
109 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
110 
111 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
112 				     unsigned long frame, int flags);
113 
114 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
115 				       unsigned long pfn);
116 
117 int gnttab_suspend(void);
118 int gnttab_resume(device_t);
119 
120 #endif /* __ASM_GNTTAB_H__ */
121