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/page.h>
  41
  42 #include <xen/interface/xen.h>
  43 #include <xen/interface/grant_table.h>
  44
  45 #include <asm/xen/hypervisor.h>
  46 #include <asm/xen/grant_table.h>
  47
  48 #include <xen/features.h>
  49
  50 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
  51 #define NR_GRANT_FRAMES 4
  52
  53 struct gnttab_free_callback {
  54         struct gnttab_free_callback *next;
  55         void (*fn)(void *);
  56         void *arg;
  57         u16 count;
  58 };
  59
  60 int gnttab_init(void);
  61 int gnttab_suspend(void);
  62 int gnttab_resume(void);
  63
  64 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
  65                                 int readonly);
  66
  67 /*
  68  * End access through the given grant reference, iff the grant entry is no
  69  * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
  70  * use.
  71  */
  72 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
  73
  74 /*
  75  * Eventually end access through the given grant reference, and once that
  76  * access has been ended, free the given page too.  Access will be ended
  77  * immediately iff the grant entry is not in use, otherwise it will happen
  78  * some time later.  page may be 0, in which case no freeing will occur.
  79  */
  80 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
  81                                unsigned long page);
  82
  83 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
  84
  85 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
  86 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
  87
  88 int gnttab_query_foreign_access(grant_ref_t ref);
  89
  90 /*
  91  * operations on reserved batches of grant references
  92  */
  93 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
  94
  95 void gnttab_free_grant_reference(grant_ref_t ref);
  96
  97 void gnttab_free_grant_references(grant_ref_t head);
  98
  99 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
 100
 101 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
 102
 103 void gnttab_release_grant_reference(grant_ref_t *private_head,
 104                                     grant_ref_t release);
 105
 106 void gnttab_request_free_callback(struct gnttab_free_callback *callback,
 107                                   void (*fn)(void *), void *arg, u16 count);
 108 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
 109
 110 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
 111                                      unsigned long frame, int readonly);
 112
 113 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
 114                                        unsigned long pfn);
 115
 116 static inline void
 117 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 118                   uint32_t flags, grant_ref_t ref, domid_t domid)
 119 {
 120         if (flags & GNTMAP_contains_pte)
 121                 map->host_addr = addr;
 122         else if (xen_feature(XENFEAT_auto_translated_physmap))
 123                 map->host_addr = __pa(addr);
 124         else
 125                 map->host_addr = addr;
 126
 127         map->flags = flags;
 128         map->ref = ref;
 129         map->dom = domid;
 130 }
 131
 132 static inline void
 133 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
 134                     uint32_t flags, grant_handle_t handle)
 135 {
 136         if (flags & GNTMAP_contains_pte)
 137                 unmap->host_addr = addr;
 138         else if (xen_feature(XENFEAT_auto_translated_physmap))
 139                 unmap->host_addr = __pa(addr);
 140         else
 141                 unmap->host_addr = addr;
 142
 143         unmap->handle = handle;
 144         unmap->dev_bus_addr = 0;
 145 }
 146
 147 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
 148                            unsigned long max_nr_gframes,
 149                            struct grant_entry **__shared);
 150 void arch_gnttab_unmap_shared(struct grant_entry *shared,
 151                               unsigned long nr_gframes);
 152
 153 extern unsigned long xen_hvm_resume_frames;
 154 unsigned int gnttab_max_grant_frames(void);
 155
 156 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 157
 158 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 159                     struct page **pages, unsigned int count);
 160 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 161                       struct page **pages, unsigned int count);
 162
 163 #endif /* __ASM_GNTTAB_H__ */