LXR linux/include/xen/grant

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