1 /****************************************************************************** 2 * SPDX-License-Identifier: MIT OR GPL-2.0-only 3 * 4 * gnttab.h 5 * 6 * Two sets of functionality: 7 * 1. Granting foreign access to our memory reservation. 8 * 2. Accessing others' memory reservations via grant references. 9 * (i.e., mechanisms for both sender and recipient of grant references) 10 * 11 * Copyright (c) 2004-2005, K A Fraser 12 * Copyright (c) 2005, Christopher Clark 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License version 2 16 * as published by the Free Software Foundation; or, when distributed 17 * separately from the Linux kernel or incorporated into other 18 * software packages, subject to the following license: 19 * 20 * Permission is hereby granted, free of charge, to any person obtaining a copy 21 * of this source file (the "Software"), to deal in the Software without 22 * restriction, including without limitation the rights to use, copy, modify, 23 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 24 * and to permit persons to whom the Software is furnished to do so, subject to 25 * the following conditions: 26 * 27 * The above copyright notice and this permission notice shall be included in 28 * all copies or substantial portions of the Software. 29 * 30 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 31 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 32 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 33 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 34 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 35 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 36 * IN THE SOFTWARE. 37 */ 38 39 #ifndef __ASM_GNTTAB_H__ 40 #define __ASM_GNTTAB_H__ 41 42 #include <xen/xen-os.h> 43 #include <xen/hypervisor.h> 44 #include <xen/features.h> 45 46 #include <contrib/xen/grant_table.h> 47 48 #define GNTTAB_LIST_END GRANT_REF_INVALID 49 50 struct gnttab_free_callback { 51 struct gnttab_free_callback *next; 52 void (*fn)(void *); 53 void *arg; 54 uint16_t count; 55 }; 56 57 /* 58 * Allocate a grant table reference and return it in *result. Returns 59 * zero on success or errno on error. 60 */ 61 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 62 int flags, grant_ref_t *result); 63 64 /* 65 * End access through the given grant reference, iff the grant entry is no 66 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 67 * use. 68 */ 69 int gnttab_end_foreign_access_ref(grant_ref_t ref); 70 71 /* 72 * Eventually end access through the given grant reference, and once that 73 * access has been ended, free the given page too. Access will be ended 74 * immediately iff the grant entry is not in use, otherwise it will happen 75 * some time later. page may be 0, in which case no freeing will occur. 76 */ 77 void gnttab_end_foreign_access(grant_ref_t ref, void *page); 78 79 /* 80 * Eventually end access through the given array of grant references. 81 * Access will be ended immediately iff the grant entry is not in use, 82 * otherwise it will happen some time later 83 */ 84 void gnttab_end_foreign_access_references(u_int count, grant_ref_t *refs); 85 86 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn, grant_ref_t *result); 87 88 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 89 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 90 91 int gnttab_query_foreign_access(grant_ref_t ref); 92 93 /* 94 * operations on reserved batches of grant references 95 */ 96 int gnttab_alloc_grant_references(uint16_t count, grant_ref_t *pprivate_head); 97 98 void gnttab_free_grant_reference(grant_ref_t ref); 99 100 void gnttab_free_grant_references(grant_ref_t head); 101 102 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 103 104 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 105 106 void gnttab_release_grant_reference(grant_ref_t *private_head, 107 grant_ref_t release); 108 109 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 110 void (*fn)(void *), void *arg, uint16_t count); 111 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 112 113 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 114 unsigned long frame, int flags); 115 116 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 117 unsigned long pfn); 118 119 int gnttab_suspend(void); 120 int gnttab_resume(device_t); 121 122 #endif /* __ASM_GNTTAB_H__ */ 123