include/xen/grant_table.h

   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/xen/hypervisor.h>
  41 #include <xen/interface/grant_table.h>
  42 #include <asm/xen/grant_table.h>
  43
  44 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
  45 #define NR_GRANT_FRAMES 4
  46
  47 struct gnttab_free_callback {
  48         struct gnttab_free_callback *next;
  49         void (*fn)(void *);
  50         void *arg;
  51         u16 count;
  52 };
  53
  54 int gnttab_init(void);
  55 int gnttab_suspend(void);
  56 int gnttab_resume(void);
  57
  58 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
  59                                 int readonly);
  60
  61 /*
  62  * End access through the given grant reference, iff the grant entry is no
  63  * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
  64  * use.
  65  */
  66 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
  67
  68 /*
  69  * Eventually end access through the given grant reference, and once that
  70  * access has been ended, free the given page too.  Access will be ended
  71  * immediately iff the grant entry is not in use, otherwise it will happen
  72  * some time later.  page may be 0, in which case no freeing will occur.
  73  */
  74 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
  75                                unsigned long page);
  76
  77 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
  78
  79 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
  80 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
  81
  82 int gnttab_query_foreign_access(grant_ref_t ref);
  83
  84 /*
  85  * operations on reserved batches of grant references
  86  */
  87 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
  88
  89 void gnttab_free_grant_reference(grant_ref_t ref);
  90
  91 void gnttab_free_grant_references(grant_ref_t head);
  92
  93 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
  94
  95 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
  96
  97 void gnttab_release_grant_reference(grant_ref_t *private_head,
  98                                     grant_ref_t release);
  99
 100 void gnttab_request_free_callback(struct gnttab_free_callback *callback,
 101                                   void (*fn)(void *), void *arg, u16 count);
 102 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
 103
 104 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
 105                                      unsigned long frame, int readonly);
 106
 107 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
 108                                        unsigned long pfn);
 109
 110 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
 111                            unsigned long max_nr_gframes,
 112                            struct grant_entry **__shared);
 113 void arch_gnttab_unmap_shared(struct grant_entry *shared,
 114                               unsigned long nr_gframes);
 115
 116 extern unsigned long xen_hvm_resume_frames;
 117 unsigned int gnttab_max_grant_frames(void);
 118
 119 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 120
 121 #endif /* __ASM_GNTTAB_H__ */