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 #include <linux/mm_types.h> 49 #include <linux/page-flags.h> 50 51 #define GNTTAB_RESERVED_XENSTORE 1 52 53 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ 54 #define NR_GRANT_FRAMES 4 55 56 struct gnttab_free_callback { 57 struct gnttab_free_callback *next; 58 void (*fn)(void *); 59 void *arg; 60 u16 count; 61 }; 62 63 struct gntab_unmap_queue_data; 64 65 typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data); 66 67 struct gntab_unmap_queue_data 68 { 69 struct delayed_work gnttab_work; 70 void *data; 71 gnttab_unmap_refs_done done; 72 struct gnttab_unmap_grant_ref *unmap_ops; 73 struct gnttab_unmap_grant_ref *kunmap_ops; 74 struct page **pages; 75 unsigned int count; 76 unsigned int age; 77 }; 78 79 int gnttab_init(void); 80 int gnttab_suspend(void); 81 int gnttab_resume(void); 82 83 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 84 int readonly); 85 86 /* 87 * End access through the given grant reference, iff the grant entry is no 88 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 89 * use. 90 */ 91 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly); 92 93 /* 94 * Eventually end access through the given grant reference, and once that 95 * access has been ended, free the given page too. Access will be ended 96 * immediately iff the grant entry is not in use, otherwise it will happen 97 * some time later. page may be 0, in which case no freeing will occur. 98 */ 99 void gnttab_end_foreign_access(grant_ref_t ref, int readonly, 100 unsigned long page); 101 102 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); 103 104 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 105 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 106 107 int gnttab_query_foreign_access(grant_ref_t ref); 108 109 /* 110 * operations on reserved batches of grant references 111 */ 112 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); 113 114 void gnttab_free_grant_reference(grant_ref_t ref); 115 116 void gnttab_free_grant_references(grant_ref_t head); 117 118 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 119 120 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 121 122 void gnttab_release_grant_reference(grant_ref_t *private_head, 123 grant_ref_t release); 124 125 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 126 void (*fn)(void *), void *arg, u16 count); 127 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 128 129 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 130 unsigned long frame, int readonly); 131 132 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 133 unsigned long pfn); 134 135 static inline void 136 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, 137 uint32_t flags, grant_ref_t ref, domid_t domid) 138 { 139 if (flags & GNTMAP_contains_pte) 140 map->host_addr = addr; 141 else if (xen_feature(XENFEAT_auto_translated_physmap)) 142 map->host_addr = __pa(addr); 143 else 144 map->host_addr = addr; 145 146 map->flags = flags; 147 map->ref = ref; 148 map->dom = domid; 149 } 150 151 static inline void 152 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, 153 uint32_t flags, grant_handle_t handle) 154 { 155 if (flags & GNTMAP_contains_pte) 156 unmap->host_addr = addr; 157 else if (xen_feature(XENFEAT_auto_translated_physmap)) 158 unmap->host_addr = __pa(addr); 159 else 160 unmap->host_addr = addr; 161 162 unmap->handle = handle; 163 unmap->dev_bus_addr = 0; 164 } 165 166 int arch_gnttab_init(unsigned long nr_shared); 167 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, 168 unsigned long max_nr_gframes, 169 void **__shared); 170 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); 171 172 struct grant_frames { 173 xen_pfn_t *pfn; 174 unsigned int count; 175 void *vaddr; 176 }; 177 extern struct grant_frames xen_auto_xlat_grant_frames; 178 unsigned int gnttab_max_grant_frames(void); 179 int gnttab_setup_auto_xlat_frames(phys_addr_t addr); 180 void gnttab_free_auto_xlat_frames(void); 181 182 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 183 184 int gnttab_alloc_pages(int nr_pages, struct page **pages); 185 void gnttab_free_pages(int nr_pages, struct page **pages); 186 187 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, 188 struct gnttab_map_grant_ref *kmap_ops, 189 struct page **pages, unsigned int count); 190 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, 191 struct gnttab_unmap_grant_ref *kunmap_ops, 192 struct page **pages, unsigned int count); 193 void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); 194 195 196 /* Perform a batch of grant map/copy operations. Retry every batch slot 197 * for which the hypervisor returns GNTST_eagain. This is typically due 198 * to paged out target frames. 199 * 200 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. 201 * 202 * Return value in each iand every status field of the batch guaranteed 203 * to not be GNTST_eagain. 204 */ 205 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); 206 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); 207 208 209 struct xen_page_foreign { 210 domid_t domid; 211 grant_ref_t gref; 212 }; 213 214 static inline struct xen_page_foreign *xen_page_foreign(struct page *page) 215 { 216 if (!PageForeign(page)) 217 return NULL; 218 #if BITS_PER_LONG < 64 219 return (struct xen_page_foreign *)page->private; 220 #else 221 BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG); 222 return (struct xen_page_foreign *)&page->private; 223 #endif 224 } 225 226 #endif /* __ASM_GNTTAB_H__ */ 227