1 /****************************************************************************** 2 * gnttab.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 <xen/xen-os.h> 41 #include <xen/hypervisor.h> 42 #include <xen/features.h> 43 44 #include <contrib/xen/grant_table.h> 45 46 #define GNTTAB_LIST_END GRANT_REF_INVALID 47 48 struct gnttab_free_callback { 49 struct gnttab_free_callback *next; 50 void (*fn)(void *); 51 void *arg; 52 uint16_t count; 53 }; 54 55 /* 56 * Allocate a grant table reference and return it in *result. Returns 57 * zero on success or errno on error. 58 */ 59 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 60 int flags, grant_ref_t *result); 61 62 /* 63 * End access through the given grant reference, iff the grant entry is no 64 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 65 * use. 66 */ 67 int gnttab_end_foreign_access_ref(grant_ref_t ref); 68 69 /* 70 * Eventually end access through the given grant reference, and once that 71 * access has been ended, free the given page too. Access will be ended 72 * immediately iff the grant entry is not in use, otherwise it will happen 73 * some time later. page may be 0, in which case no freeing will occur. 74 */ 75 void gnttab_end_foreign_access(grant_ref_t ref, void *page); 76 77 /* 78 * Eventually end access through the given array of grant references. 79 * Access will be ended immediately iff the grant entry is not in use, 80 * otherwise it will happen some time later 81 */ 82 void gnttab_end_foreign_access_references(u_int count, grant_ref_t *refs); 83 84 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn, grant_ref_t *result); 85 86 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 87 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 88 89 int gnttab_query_foreign_access(grant_ref_t ref); 90 91 /* 92 * operations on reserved batches of grant references 93 */ 94 int gnttab_alloc_grant_references(uint16_t count, grant_ref_t *pprivate_head); 95 96 void gnttab_free_grant_reference(grant_ref_t ref); 97 98 void gnttab_free_grant_references(grant_ref_t head); 99 100 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 101 102 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 103 104 void gnttab_release_grant_reference(grant_ref_t *private_head, 105 grant_ref_t release); 106 107 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 108 void (*fn)(void *), void *arg, uint16_t count); 109 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 110 111 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 112 unsigned long frame, int flags); 113 114 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 115 unsigned long pfn); 116 117 int gnttab_suspend(void); 118 int gnttab_resume(device_t); 119 120 #endif /* __ASM_GNTTAB_H__ */ 121