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 map->status = 1; /* arbitrary positive value */ 161 } 162 163 static inline void 164 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, 165 uint32_t flags, grant_handle_t handle) 166 { 167 if (flags & GNTMAP_contains_pte) 168 unmap->host_addr = addr; 169 else if (xen_feature(XENFEAT_auto_translated_physmap)) 170 unmap->host_addr = __pa(addr); 171 else 172 unmap->host_addr = addr; 173 174 unmap->handle = handle; 175 unmap->dev_bus_addr = 0; 176 } 177 178 int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status); 179 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, 180 unsigned long max_nr_gframes, 181 void **__shared); 182 int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes, 183 unsigned long max_nr_gframes, 184 grant_status_t **__shared); 185 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); 186 187 struct grant_frames { 188 xen_pfn_t *pfn; 189 unsigned int count; 190 void *vaddr; 191 }; 192 extern struct grant_frames xen_auto_xlat_grant_frames; 193 unsigned int gnttab_max_grant_frames(void); 194 int gnttab_setup_auto_xlat_frames(phys_addr_t addr); 195 void gnttab_free_auto_xlat_frames(void); 196 197 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 198 199 int gnttab_alloc_pages(int nr_pages, struct page **pages); 200 void gnttab_free_pages(int nr_pages, struct page **pages); 201 202 struct gnttab_page_cache { 203 spinlock_t lock; 204 #ifdef CONFIG_XEN_UNPOPULATED_ALLOC 205 struct page *pages; 206 #else 207 struct list_head pages; 208 #endif 209 unsigned int num_pages; 210 }; 211 212 void gnttab_page_cache_init(struct gnttab_page_cache *cache); 213 int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page); 214 void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page, 215 unsigned int num); 216 void gnttab_page_cache_shrink(struct gnttab_page_cache *cache, 217 unsigned int num); 218 219 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC 220 struct gnttab_dma_alloc_args { 221 /* Device for which DMA memory will be/was allocated. */ 222 struct device *dev; 223 /* If set then DMA buffer is coherent and write-combine otherwise. */ 224 bool coherent; 225 226 int nr_pages; 227 struct page **pages; 228 xen_pfn_t *frames; 229 void *vaddr; 230 dma_addr_t dev_bus_addr; 231 }; 232 233 int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args); 234 int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args); 235 #endif 236 237 int gnttab_pages_set_private(int nr_pages, struct page **pages); 238 void gnttab_pages_clear_private(int nr_pages, struct page **pages); 239 240 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, 241 struct gnttab_map_grant_ref *kmap_ops, 242 struct page **pages, unsigned int count); 243 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, 244 struct gnttab_unmap_grant_ref *kunmap_ops, 245 struct page **pages, unsigned int count); 246 void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); 247 int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item); 248 249 250 /* Perform a batch of grant map/copy operations. Retry every batch slot 251 * for which the hypervisor returns GNTST_eagain. This is typically due 252 * to paged out target frames. 253 * 254 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. 255 * 256 * Return value in each iand every status field of the batch guaranteed 257 * to not be GNTST_eagain. 258 */ 259 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); 260 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); 261 262 263 struct xen_page_foreign { 264 domid_t domid; 265 grant_ref_t gref; 266 }; 267 268 static inline struct xen_page_foreign *xen_page_foreign(struct page *page) 269 { 270 if (!PageForeign(page)) 271 return NULL; 272 #if BITS_PER_LONG < 64 273 return (struct xen_page_foreign *)page->private; 274 #else 275 BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG); 276 return (struct xen_page_foreign *)&page->private; 277 #endif 278 } 279 280 /* Split Linux page in chunk of the size of the grant and call fn 281 * 282 * Parameters of fn: 283 * gfn: guest frame number 284 * offset: offset in the grant 285 * len: length of the data in the grant. 286 * data: internal information 287 */ 288 typedef void (*xen_grant_fn_t)(unsigned long gfn, unsigned int offset, 289 unsigned int len, void *data); 290 291 void gnttab_foreach_grant_in_range(struct page *page, 292 unsigned int offset, 293 unsigned int len, 294 xen_grant_fn_t fn, 295 void *data); 296 297 /* Helper to get to call fn only on the first "grant chunk" */ 298 static inline void gnttab_for_one_grant(struct page *page, unsigned int offset, 299 unsigned len, xen_grant_fn_t fn, 300 void *data) 301 { 302 /* The first request is limited to the size of one grant */ 303 len = min_t(unsigned int, XEN_PAGE_SIZE - (offset & ~XEN_PAGE_MASK), 304 len); 305 306 gnttab_foreach_grant_in_range(page, offset, len, fn, data); 307 } 308 309 /* Get @nr_grefs grants from an array of page and call fn for each grant */ 310 void gnttab_foreach_grant(struct page **pages, 311 unsigned int nr_grefs, 312 xen_grant_fn_t fn, 313 void *data); 314 315 /* Get the number of grant in a specified region 316 * 317 * start: Offset from the beginning of the first page 318 * len: total length of data (can cross multiple page) 319 */ 320 static inline unsigned int gnttab_count_grant(unsigned int start, 321 unsigned int len) 322 { 323 return XEN_PFN_UP(xen_offset_in_page(start) + len); 324 } 325 326 #endif /* __ASM_GNTTAB_H__ */ 327