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);
  67
  68/*
  69 * End access through the given grant reference, iff the grant entry is no
  70 * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
  71 * use.
  72 */
  73int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
  74
  75/*
  76 * Eventually end access through the given grant reference, and once that
  77 * access has been ended, free the given page too.  Access will be ended
  78 * immediately iff the grant entry is not in use, otherwise it will happen
  79 * some time later.  page may be 0, in which case no freeing will occur.
  80 */
  81void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
  82                               unsigned long page);
  83
  84int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
  85
  86unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
  87unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
  88
  89int gnttab_query_foreign_access(grant_ref_t ref);
  90
  91/*
  92 * operations on reserved batches of grant references
  93 */
  94int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
  95
  96void gnttab_free_grant_reference(grant_ref_t ref);
  97
  98void gnttab_free_grant_references(grant_ref_t head);
  99
 100int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
 101
 102int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
 103
 104void gnttab_release_grant_reference(grant_ref_t *private_head,
 105                                    grant_ref_t release);
 106
 107void gnttab_request_free_callback(struct gnttab_free_callback *callback,
 108                                  void (*fn)(void *), void *arg, u16 count);
 109void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
 110
 111void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
 112                                     unsigned long frame, int readonly);
 113
 114void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
 115                                       unsigned long pfn);
 116
 117static inline void
 118gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 119                  uint32_t flags, grant_ref_t ref, domid_t domid)
 120{
 121        if (flags & GNTMAP_contains_pte)
 122                map->host_addr = addr;
 123        else if (xen_feature(XENFEAT_auto_translated_physmap))
 124                map->host_addr = __pa(addr);
 125        else
 126                map->host_addr = addr;
 127
 128        map->flags = flags;
 129        map->ref = ref;
 130        map->dom = domid;
 131}
 132
 133static inline void
 134gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
 135                    uint32_t flags, grant_handle_t handle)
 136{
 137        if (flags & GNTMAP_contains_pte)
 138                unmap->host_addr = addr;
 139        else if (xen_feature(XENFEAT_auto_translated_physmap))
 140                unmap->host_addr = __pa(addr);
 141        else
 142                unmap->host_addr = addr;
 143
 144        unmap->handle = handle;
 145        unmap->dev_bus_addr = 0;
 146}
 147
 148int arch_gnttab_init(unsigned long nr_shared);
 149int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes,
 150                           unsigned long max_nr_gframes,
 151                           void **__shared);
 152void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
 153
 154struct grant_frames {
 155        xen_pfn_t *pfn;
 156        unsigned int count;
 157        void *vaddr;
 158};
 159extern struct grant_frames xen_auto_xlat_grant_frames;
 160unsigned int gnttab_max_grant_frames(void);
 161int gnttab_setup_auto_xlat_frames(phys_addr_t addr);
 162void gnttab_free_auto_xlat_frames(void);
 163
 164#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 165
 166int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 167                    struct gnttab_map_grant_ref *kmap_ops,
 168                    struct page **pages, unsigned int count);
 169int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 170                      struct gnttab_map_grant_ref *kunmap_ops,
 171                      struct page **pages, unsigned int count);
 172
 173/* Perform a batch of grant map/copy operations. Retry every batch slot
 174 * for which the hypervisor returns GNTST_eagain. This is typically due
 175 * to paged out target frames.
 176 *
 177 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds.
 178 *
 179 * Return value in each iand every status field of the batch guaranteed
 180 * to not be GNTST_eagain.
 181 */
 182void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
 183void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
 184
 185#endif /* __ASM_GNTTAB_H__ */
 186