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 <xen/page.h> 49 #include <linux/mm_types.h> 50 #include <linux/page-flags.h> 51 #include <linux/kernel.h> 52 53 #define GNTTAB_RESERVED_XENSTORE 1 54 55 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ 56 #define NR_GRANT_FRAMES 4 57 58 struct gnttab_free_callback { 59 struct gnttab_free_callback *next; 60 void (*fn)(void *); 61 void *arg; 62 u16 count; 63 }; 64 65 struct gntab_unmap_queue_data; 66 67 typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data); 68 69 struct gntab_unmap_queue_data 70 { 71 struct delayed_work gnttab_work; 72 void *data; 73 gnttab_unmap_refs_done done; 74 struct gnttab_unmap_grant_ref *unmap_ops; 75 struct gnttab_unmap_grant_ref *kunmap_ops; 76 struct page **pages; 77 unsigned int count; 78 unsigned int age; 79 }; 80 81 int gnttab_init(void); 82 int gnttab_suspend(void); 83 int gnttab_resume(void); 84 85 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 86 int readonly); 87 88 /* 89 * End access through the given grant reference, iff the grant entry is no 90 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 91 * use. 92 */ 93 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly); 94 95 /* 96 * Eventually end access through the given grant reference, and once that 97 * access has been ended, free the given page too. Access will be ended 98 * immediately iff the grant entry is not in use, otherwise it will happen 99 * some time later. page may be 0, in which case no freeing will occur. 100 */ 101 void gnttab_end_foreign_access(grant_ref_t ref, int readonly, 102 unsigned long page); 103 104 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); 105 106 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 107 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 108 109 int gnttab_query_foreign_access(grant_ref_t ref); 110 111 /* 112 * operations on reserved batches of grant references 113 */ 114 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); 115 116 void gnttab_free_grant_reference(grant_ref_t ref); 117 118 void gnttab_free_grant_references(grant_ref_t head); 119 120 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 121 122 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 123 124 void gnttab_release_grant_reference(grant_ref_t *private_head, 125 grant_ref_t release); 126 127 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 128 void (*fn)(void *), void *arg, u16 count); 129 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 130 131 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 132 unsigned long frame, int readonly); 133 134 /* Give access to the first 4K of the page */ 135 static inline void gnttab_page_grant_foreign_access_ref_one( 136 grant_ref_t ref, domid_t domid, 137 struct page *page, int readonly) 138 { 139 gnttab_grant_foreign_access_ref(ref, domid, xen_page_to_gfn(page), 140 readonly); 141 } 142 143 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 144 unsigned long pfn); 145 146 static inline void 147 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, 148 uint32_t flags, grant_ref_t ref, domid_t domid) 149 { 150 if (flags & GNTMAP_contains_pte) 151 map->host_addr = addr; 152 else if (xen_feature(XENFEAT_auto_translated_physmap)) 153 map->host_addr = __pa(addr); 154 else 155 map->host_addr = addr; 156 157 map->flags = flags; 158 map->ref = ref; 159 map->dom = domid; 160 } 161 162 static inline void 163 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, 164 uint32_t flags, grant_handle_t handle) 165 { 166 if (flags & GNTMAP_contains_pte) 167 unmap->host_addr = addr; 168 else if (xen_feature(XENFEAT_auto_translated_physmap)) 169 unmap->host_addr = __pa(addr); 170 else 171 unmap->host_addr = addr; 172 173 unmap->handle = handle; 174 unmap->dev_bus_addr = 0; 175 } 176 177 int arch_gnttab_init(unsigned long nr_shared); 178 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, 179 unsigned long max_nr_gframes, 180 void **__shared); 181 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); 182 183 struct grant_frames { 184 xen_pfn_t *pfn; 185 unsigned int count; 186 void *vaddr; 187 }; 188 extern struct grant_frames xen_auto_xlat_grant_frames; 189 unsigned int gnttab_max_grant_frames(void); 190 int gnttab_setup_auto_xlat_frames(phys_addr_t addr); 191 void gnttab_free_auto_xlat_frames(void); 192 193 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 194 195 int gnttab_alloc_pages(int nr_pages, struct page **pages); 196 void gnttab_free_pages(int nr_pages, struct page **pages); 197 198 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, 199 struct gnttab_map_grant_ref *kmap_ops, 200 struct page **pages, unsigned int count); 201 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, 202 struct gnttab_unmap_grant_ref *kunmap_ops, 203 struct page **pages, unsigned int count); 204 void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); 205 int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item); 206 207 208 /* Perform a batch of grant map/copy operations. Retry every batch slot 209 * for which the hypervisor returns GNTST_eagain. This is typically due 210 * to paged out target frames. 211 * 212 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. 213 * 214 * Return value in each iand every status field of the batch guaranteed 215 * to not be GNTST_eagain. 216 */ 217 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); 218 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); 219 220 221 struct xen_page_foreign { 222 domid_t domid; 223 grant_ref_t gref; 224 }; 225 226 static inline struct xen_page_foreign *xen_page_foreign(struct page *page) 227 { 228 if (!PageForeign(page)) 229 return NULL; 230 #if BITS_PER_LONG < 64 231 return (struct xen_page_foreign *)page->private; 232 #else 233 BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG); 234 return (struct xen_page_foreign *)&page->private; 235 #endif 236 } 237 238 /* Split Linux page in chunk of the size of the grant and call fn 239 * 240 * Parameters of fn: 241 * gfn: guest frame number 242 * offset: offset in the grant 243 * len: length of the data in the grant. 244 * data: internal information 245 */ 246 typedef void (*xen_grant_fn_t)(unsigned long gfn, unsigned int offset, 247 unsigned int len, void *data); 248 249 void gnttab_foreach_grant_in_range(struct page *page, 250 unsigned int offset, 251 unsigned int len, 252 xen_grant_fn_t fn, 253 void *data); 254 255 /* Helper to get to call fn only on the first "grant chunk" */ 256 static inline void gnttab_for_one_grant(struct page *page, unsigned int offset, 257 unsigned len, xen_grant_fn_t fn, 258 void *data) 259 { 260 /* The first request is limited to the size of one grant */ 261 len = min_t(unsigned int, XEN_PAGE_SIZE - (offset & ~XEN_PAGE_MASK), 262 len); 263 264 gnttab_foreach_grant_in_range(page, offset, len, fn, data); 265 } 266 267 /* Get @nr_grefs grants from an array of page and call fn for each grant */ 268 void gnttab_foreach_grant(struct page **pages, 269 unsigned int nr_grefs, 270 xen_grant_fn_t fn, 271 void *data); 272 273 /* Get the number of grant in a specified region 274 * 275 * start: Offset from the beginning of the first page 276 * len: total length of data (can cross multiple page) 277 */ 278 static inline unsigned int gnttab_count_grant(unsigned int start, 279 unsigned int len) 280 { 281 return XEN_PFN_UP(xen_offset_in_page(start) + len); 282 } 283 284 #endif /* __ASM_GNTTAB_H__ */ 285