Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
grant_table.h
Go to the documentation of this file.
1 /******************************************************************************
2  * grant_table.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 <asm/page.h>
41 
42 #include <xen/interface/xen.h>
44 
45 #include <asm/xen/hypervisor.h>
46 
47 #include <xen/features.h>
48 
49 #define GNTTAB_RESERVED_XENSTORE 1
50 
51 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
52 #define NR_GRANT_FRAMES 4
53 
56  void (*fn)(void *);
57  void *arg;
59 };
60 
61 int gnttab_init(void);
62 int gnttab_suspend(void);
63 int gnttab_resume(void);
64 
66  int readonly);
68  int flags, unsigned page_off,
69  unsigned length);
71  domid_t trans_domid,
72  grant_ref_t trans_gref);
73 
74 /*
75  * Are sub-page grants available on this version of Xen? Returns true if they
76  * are, and false if they're not.
77  */
79 
80 /*
81  * Are transitive grants available on this version of Xen? Returns true if they
82  * are, and false if they're not.
83  */
85 
86 /*
87  * End access through the given grant reference, iff the grant entry is no
88  * longer in use. Return 1 if the grant entry was freed, 0 if it is still in
89  * use.
90  */
92 
93 /*
94  * Eventually end access through the given grant reference, and once that
95  * access has been ended, free the given page too. Access will be ended
96  * immediately iff the grant entry is not in use, otherwise it will happen
97  * some time later. page may be 0, in which case no freeing will occur.
98  */
100  unsigned long page);
101 
102 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
103 
105 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
106 
108 
109 /*
110  * operations on reserved batches of grant references
111  */
113 
115 
117 
118 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
119 
120 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
121 
124 
126  void (*fn)(void *), void *arg, u16 count);
128 
130  unsigned long frame, int readonly);
132  unsigned long frame, int flags,
133  unsigned page_off,
134  unsigned length);
136  int flags, domid_t trans_domid,
137  grant_ref_t trans_gref);
138 
140  unsigned long pfn);
141 
142 static inline void
143 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
145 {
146  if (flags & GNTMAP_contains_pte)
147  map->host_addr = addr;
148  else if (xen_feature(XENFEAT_auto_translated_physmap))
149  map->host_addr = __pa(addr);
150  else
151  map->host_addr = addr;
152 
153  map->flags = flags;
154  map->ref = ref;
155  map->dom = domid;
156 }
157 
158 static inline void
159 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
161 {
162  if (flags & GNTMAP_contains_pte)
163  unmap->host_addr = addr;
164  else if (xen_feature(XENFEAT_auto_translated_physmap))
165  unmap->host_addr = __pa(addr);
166  else
167  unmap->host_addr = addr;
168 
169  unmap->handle = handle;
170  unmap->dev_bus_addr = 0;
171 }
172 
173 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes,
174  unsigned long max_nr_gframes,
175  void **__shared);
176 int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
177  unsigned long max_nr_gframes,
178  grant_status_t **__shared);
179 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
180 
181 extern unsigned long xen_hvm_resume_frames;
182 unsigned int gnttab_max_grant_frames(void);
183 
184 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
185 
186 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
187  struct gnttab_map_grant_ref *kmap_ops,
188  struct page **pages, unsigned int count);
189 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
190  struct gnttab_map_grant_ref *kunmap_ops,
191  struct page **pages, unsigned int count);
192 
193 /* Perform a batch of grant map/copy operations. Retry every batch slot
194  * for which the hypervisor returns GNTST_eagain. This is typically due
195  * to paged out target frames.
196  *
197  * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds.
198  *
199  * Return value in each iand every status field of the batch guaranteed
200  * to not be GNTST_eagain.
201  */
202 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
203 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
204 
205 #endif /* __ASM_GNTTAB_H__ */