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 #define GNTTAB_RESERVED_XENSTORE 1 50 51 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ 52 #define NR_GRANT_FRAMES 4 53 54 struct gnttab_free_callback { 55 struct gnttab_free_callback *next; 56 void (*fn)(void *); 57 void *arg; 58 u16 count; 59 }; 60 61 int gnttab_init(void); 62 int gnttab_suspend(void); 63 int gnttab_resume(void); 64 65 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 66 int readonly); 67 68 /* 69 * End access through the given grant reference, iff the grant entry is no 70 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 71 * use. 72 */ 73 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly); 74 75 /* 76 * Eventually end access through the given grant reference, and once that 77 * access has been ended, free the given page too. Access will be ended 78 * immediately iff the grant entry is not in use, otherwise it will happen 79 * some time later. page may be 0, in which case no freeing will occur. 80 */ 81 void gnttab_end_foreign_access(grant_ref_t ref, int readonly, 82 unsigned long page); 83 84 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); 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(u16 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, u16 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 readonly); 113 114 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 115 unsigned long pfn); 116 117 static inline void 118 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, 119 uint32_t flags, grant_ref_t ref, domid_t domid) 120 { 121 if (flags & GNTMAP_contains_pte) 122 map->host_addr = addr; 123 else if (xen_feature(XENFEAT_auto_translated_physmap)) 124 map->host_addr = __pa(addr); 125 else 126 map->host_addr = addr; 127 128 map->flags = flags; 129 map->ref = ref; 130 map->dom = domid; 131 } 132 133 static inline void 134 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, 135 uint32_t flags, grant_handle_t handle) 136 { 137 if (flags & GNTMAP_contains_pte) 138 unmap->host_addr = addr; 139 else if (xen_feature(XENFEAT_auto_translated_physmap)) 140 unmap->host_addr = __pa(addr); 141 else 142 unmap->host_addr = addr; 143 144 unmap->handle = handle; 145 unmap->dev_bus_addr = 0; 146 } 147 148 int arch_gnttab_init(unsigned long nr_shared); 149 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, 150 unsigned long max_nr_gframes, 151 void **__shared); 152 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); 153 154 struct grant_frames { 155 xen_pfn_t *pfn; 156 unsigned int count; 157 void *vaddr; 158 }; 159 extern struct grant_frames xen_auto_xlat_grant_frames; 160 unsigned int gnttab_max_grant_frames(void); 161 int gnttab_setup_auto_xlat_frames(phys_addr_t addr); 162 void gnttab_free_auto_xlat_frames(void); 163 164 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 165 166 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, 167 struct gnttab_map_grant_ref *kmap_ops, 168 struct page **pages, unsigned int count); 169 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, 170 struct gnttab_map_grant_ref *kunmap_ops, 171 struct page **pages, unsigned int count); 172 173 /* Perform a batch of grant map/copy operations. Retry every batch slot 174 * for which the hypervisor returns GNTST_eagain. This is typically due 175 * to paged out target frames. 176 * 177 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. 178 * 179 * Return value in each iand every status field of the batch guaranteed 180 * to not be GNTST_eagain. 181 */ 182 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); 183 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); 184 185 #endif /* __ASM_GNTTAB_H__ */ 186