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/xen/hypervisor.h> 41 #include <xen/interface/grant_table.h> 42 43 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ 44 #define NR_GRANT_FRAMES 4 45 46 struct gnttab_free_callback { 47 struct gnttab_free_callback *next; 48 void (*fn)(void *); 49 void *arg; 50 u16 count; 51 }; 52 53 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 54 int readonly); 55 56 /* 57 * End access through the given grant reference, iff the grant entry is no 58 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 59 * use. 60 */ 61 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly); 62 63 /* 64 * Eventually end access through the given grant reference, and once that 65 * access has been ended, free the given page too. Access will be ended 66 * immediately iff the grant entry is not in use, otherwise it will happen 67 * some time later. page may be 0, in which case no freeing will occur. 68 */ 69 void gnttab_end_foreign_access(grant_ref_t ref, int readonly, 70 unsigned long page); 71 72 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); 73 74 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 75 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 76 77 int gnttab_query_foreign_access(grant_ref_t ref); 78 79 /* 80 * operations on reserved batches of grant references 81 */ 82 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); 83 84 void gnttab_free_grant_reference(grant_ref_t ref); 85 86 void gnttab_free_grant_references(grant_ref_t head); 87 88 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 89 90 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 91 92 void gnttab_release_grant_reference(grant_ref_t *private_head, 93 grant_ref_t release); 94 95 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 96 void (*fn)(void *), void *arg, u16 count); 97 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 98 99 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 100 unsigned long frame, int readonly); 101 102 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 103 unsigned long pfn); 104 105 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 106 107 #endif /* __ASM_GNTTAB_H__ */ 108