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 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ 50 #define NR_GRANT_FRAMES 4 51 52 struct gnttab_free_callback { 53 struct gnttab_free_callback *next; 54 void (*fn)(void *); 55 void *arg; 56 u16 count; 57 }; 58 59 int gnttab_init(void); 60 int gnttab_suspend(void); 61 int gnttab_resume(void); 62 63 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 64 int readonly); 65 int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, 66 int flags, unsigned page_off, 67 unsigned length); 68 int gnttab_grant_foreign_access_trans(domid_t domid, int flags, 69 domid_t trans_domid, 70 grant_ref_t trans_gref); 71 72 /* 73 * Are sub-page grants available on this version of Xen? Returns true if they 74 * are, and false if they're not. 75 */ 76 bool gnttab_subpage_grants_available(void); 77 78 /* 79 * Are transitive grants available on this version of Xen? Returns true if they 80 * are, and false if they're not. 81 */ 82 bool gnttab_trans_grants_available(void); 83 84 /* 85 * End access through the given grant reference, iff the grant entry is no 86 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 87 * use. 88 */ 89 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly); 90 91 /* 92 * Eventually end access through the given grant reference, and once that 93 * access has been ended, free the given page too. Access will be ended 94 * immediately iff the grant entry is not in use, otherwise it will happen 95 * some time later. page may be 0, in which case no freeing will occur. 96 */ 97 void gnttab_end_foreign_access(grant_ref_t ref, int readonly, 98 unsigned long page); 99 100 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); 101 102 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 103 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 104 105 int gnttab_query_foreign_access(grant_ref_t ref); 106 107 /* 108 * operations on reserved batches of grant references 109 */ 110 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); 111 112 void gnttab_free_grant_reference(grant_ref_t ref); 113 114 void gnttab_free_grant_references(grant_ref_t head); 115 116 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 117 118 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 119 120 void gnttab_release_grant_reference(grant_ref_t *private_head, 121 grant_ref_t release); 122 123 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 124 void (*fn)(void *), void *arg, u16 count); 125 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 126 127 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 128 unsigned long frame, int readonly); 129 int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, 130 unsigned long frame, int flags, 131 unsigned page_off, 132 unsigned length); 133 int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, 134 int flags, domid_t trans_domid, 135 grant_ref_t trans_gref); 136 137 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 138 unsigned long pfn); 139 140 static inline void 141 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, 142 uint32_t flags, grant_ref_t ref, domid_t domid) 143 { 144 if (flags & GNTMAP_contains_pte) 145 map->host_addr = addr; 146 else if (xen_feature(XENFEAT_auto_translated_physmap)) 147 map->host_addr = __pa(addr); 148 else 149 map->host_addr = addr; 150 151 map->flags = flags; 152 map->ref = ref; 153 map->dom = domid; 154 } 155 156 static inline void 157 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, 158 uint32_t flags, grant_handle_t handle) 159 { 160 if (flags & GNTMAP_contains_pte) 161 unmap->host_addr = addr; 162 else if (xen_feature(XENFEAT_auto_translated_physmap)) 163 unmap->host_addr = __pa(addr); 164 else 165 unmap->host_addr = addr; 166 167 unmap->handle = handle; 168 unmap->dev_bus_addr = 0; 169 } 170 171 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes, 172 unsigned long max_nr_gframes, 173 void **__shared); 174 int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes, 175 unsigned long max_nr_gframes, 176 grant_status_t **__shared); 177 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); 178 179 extern unsigned long xen_hvm_resume_frames; 180 unsigned int gnttab_max_grant_frames(void); 181 182 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 183 184 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, 185 struct gnttab_map_grant_ref *kmap_ops, 186 struct page **pages, unsigned int count); 187 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, 188 struct page **pages, unsigned int count, bool clear_pte); 189 190 #endif /* __ASM_GNTTAB_H__ */ 191