1 /******************************************************************************
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)
9 * Copyright (c) 2004-2005, K A Fraser
10 * Copyright (c) 2005, Christopher Clark
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:
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:
25 * The above copyright notice and this permission notice shall be included in
26 * all copies or substantial portions of the Software.
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
37 #ifndef __ASM_GNTTAB_H__
38 #define __ASM_GNTTAB_H__
40 #include <asm/xen/hypervisor.h>
41 #include <xen/interface/grant_table.h>
42 #include <asm/xen/grant_table.h>
44 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
45 #define NR_GRANT_FRAMES 4
47 struct gnttab_free_callback {
48 struct gnttab_free_callback *next;
54 int gnttab_suspend(void);
55 int gnttab_resume(void);
57 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
61 * End access through the given grant reference, iff the grant entry is no
62 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in
65 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
68 * Eventually end access through the given grant reference, and once that
69 * access has been ended, free the given page too. Access will be ended
70 * immediately iff the grant entry is not in use, otherwise it will happen
71 * some time later. page may be 0, in which case no freeing will occur.
73 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
76 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
78 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
79 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
81 int gnttab_query_foreign_access(grant_ref_t ref);
84 * operations on reserved batches of grant references
86 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
88 void gnttab_free_grant_reference(grant_ref_t ref);
90 void gnttab_free_grant_references(grant_ref_t head);
92 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
94 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
96 void gnttab_release_grant_reference(grant_ref_t *private_head,
99 void gnttab_request_free_callback(struct gnttab_free_callback *callback,
100 void (*fn)(void *), void *arg, u16 count);
101 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
103 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
104 unsigned long frame, int readonly);
106 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
109 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
110 unsigned long max_nr_gframes,
111 struct grant_entry **__shared);
112 void arch_gnttab_unmap_shared(struct grant_entry *shared,
113 unsigned long nr_gframes);
115 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
117 #endif /* __ASM_GNTTAB_H__ */