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/page.h>
  41
  42#include <xen/interface/xen.h>
  43#include <xen/interface/grant_table.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
  54struct gnttab_free_callback {
  55        struct gnttab_free_callback *next;
  56        void (*fn)(void *);
  57        void *arg;
  58        u16 count;
  59};
  60
  61int gnttab_init(void);
  62int gnttab_suspend(void);
  63int gnttab_resume(void);
  64
  65int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
  66                                int readonly);
  67int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame,
  68                                        int flags, unsigned page_off,
  69                                        unsigned length);
  70int gnttab_grant_foreign_access_trans(domid_t domid, int flags,
  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 */
  78bool gnttab_subpage_grants_available(void);
  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 */
  84bool gnttab_trans_grants_available(void);
  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 */
  91int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
  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 */
  99void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
 100                               unsigned long page);
 101
 102int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
 103
 104unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
 105unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
 106
 107int gnttab_query_foreign_access(grant_ref_t ref);
 108
 109/*
 110 * operations on reserved batches of grant references
 111 */
 112int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
 113
 114void gnttab_free_grant_reference(grant_ref_t ref);
 115
 116void gnttab_free_grant_references(grant_ref_t head);
 117
 118int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
 119
 120int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
 121
 122void gnttab_release_grant_reference(grant_ref_t *private_head,
 123                                    grant_ref_t release);
 124
 125void gnttab_request_free_callback(struct gnttab_free_callback *callback,
 126                                  void (*fn)(void *), void *arg, u16 count);
 127void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
 128
 129void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
 130                                     unsigned long frame, int readonly);
 131int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid,
 132                                            unsigned long frame, int flags,
 133                                            unsigned page_off,
 134                                            unsigned length);
 135int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid,
 136                                          int flags, domid_t trans_domid,
 137                                          grant_ref_t trans_gref);
 138
 139void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
 140                                       unsigned long pfn);
 141
 142static inline void
 143gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 144                  uint32_t flags, grant_ref_t ref, domid_t domid)
 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
 158static inline void
 159gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
 160                    uint32_t flags, grant_handle_t handle)
 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
 173int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
 174                           unsigned long max_nr_gframes,
 175                           void **__shared);
 176int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
 177                           unsigned long max_nr_gframes,
 178                           grant_status_t **__shared);
 179void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
 180
 181extern unsigned long xen_hvm_resume_frames;
 182unsigned int gnttab_max_grant_frames(void);
 183
 184#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 185
 186int 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);
 189int 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#endif /* __ASM_GNTTAB_H__ */
 194