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 | /* |
54 | * Technically there's no reliably invalid grant reference or grant handle, |
55 | * so pick the value that is the most unlikely one to be observed valid. |
56 | */ |
57 | #define INVALID_GRANT_REF ((grant_ref_t)-1) |
58 | #define INVALID_GRANT_HANDLE ((grant_handle_t)-1) |
59 | |
60 | /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ |
61 | #define NR_GRANT_FRAMES 4 |
62 | |
63 | struct gnttab_free_callback { |
64 | struct gnttab_free_callback *next; |
65 | void (*fn)(void *); |
66 | void *arg; |
67 | u16 count; |
68 | }; |
69 | |
70 | struct gntab_unmap_queue_data; |
71 | |
72 | typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data); |
73 | |
74 | struct gntab_unmap_queue_data |
75 | { |
76 | struct delayed_work gnttab_work; |
77 | void *data; |
78 | gnttab_unmap_refs_done done; |
79 | struct gnttab_unmap_grant_ref *unmap_ops; |
80 | struct gnttab_unmap_grant_ref *kunmap_ops; |
81 | struct page **pages; |
82 | unsigned int count; |
83 | unsigned int age; |
84 | }; |
85 | |
86 | int gnttab_init(void); |
87 | int gnttab_suspend(void); |
88 | int gnttab_resume(void); |
89 | |
90 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, |
91 | int readonly); |
92 | |
93 | /* |
94 | * End access through the given grant reference, iff the grant entry is no |
95 | * longer in use. Return 1 if the grant entry was freed, 0 if it is still in |
96 | * use. |
97 | */ |
98 | int gnttab_end_foreign_access_ref(grant_ref_t ref); |
99 | |
100 | /* |
101 | * Eventually end access through the given grant reference, and once that |
102 | * access has been ended, free the given page too. Access will be ended |
103 | * immediately iff the grant entry is not in use, otherwise it will happen |
104 | * some time later. page may be NULL, in which case no freeing will occur. |
105 | * Note that the granted page might still be accessed (read or write) by the |
106 | * other side after gnttab_end_foreign_access() returns, so even if page was |
107 | * specified as NULL it is not allowed to just reuse the page for other |
108 | * purposes immediately. gnttab_end_foreign_access() will take an additional |
109 | * reference to the granted page in this case, which is dropped only after |
110 | * the grant is no longer in use. |
111 | * This requires that multi page allocations for areas subject to |
112 | * gnttab_end_foreign_access() are done via alloc_pages_exact() (and freeing |
113 | * via free_pages_exact()) in order to avoid high order pages. |
114 | */ |
115 | void gnttab_end_foreign_access(grant_ref_t ref, struct page *page); |
116 | |
117 | /* |
118 | * End access through the given grant reference, iff the grant entry is |
119 | * no longer in use. In case of success ending foreign access, the |
120 | * grant reference is deallocated. |
121 | * Return 1 if the grant entry was freed, 0 if it is still in use. |
122 | */ |
123 | int gnttab_try_end_foreign_access(grant_ref_t ref); |
124 | |
125 | /* |
126 | * operations on reserved batches of grant references |
127 | */ |
128 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); |
129 | |
130 | int gnttab_alloc_grant_reference_seq(unsigned int count, grant_ref_t *first); |
131 | |
132 | void gnttab_free_grant_reference(grant_ref_t ref); |
133 | |
134 | void gnttab_free_grant_references(grant_ref_t head); |
135 | |
136 | void gnttab_free_grant_reference_seq(grant_ref_t head, unsigned int count); |
137 | |
138 | int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); |
139 | |
140 | int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); |
141 | |
142 | void gnttab_release_grant_reference(grant_ref_t *private_head, |
143 | grant_ref_t release); |
144 | |
145 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, |
146 | void (*fn)(void *), void *arg, u16 count); |
147 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); |
148 | |
149 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, |
150 | unsigned long frame, int readonly); |
151 | |
152 | /* Give access to the first 4K of the page */ |
153 | static inline void gnttab_page_grant_foreign_access_ref_one( |
154 | grant_ref_t ref, domid_t domid, |
155 | struct page *page, int readonly) |
156 | { |
157 | gnttab_grant_foreign_access_ref(ref, domid, frame: xen_page_to_gfn(page), |
158 | readonly); |
159 | } |
160 | |
161 | static inline void |
162 | gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, |
163 | uint32_t flags, grant_ref_t ref, domid_t domid) |
164 | { |
165 | if (flags & GNTMAP_contains_pte) |
166 | map->host_addr = addr; |
167 | else if (xen_feature(XENFEAT_auto_translated_physmap)) |
168 | map->host_addr = __pa(addr); |
169 | else |
170 | map->host_addr = addr; |
171 | |
172 | map->flags = flags; |
173 | map->ref = ref; |
174 | map->dom = domid; |
175 | map->status = 1; /* arbitrary positive value */ |
176 | } |
177 | |
178 | static inline void |
179 | gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, |
180 | uint32_t flags, grant_handle_t handle) |
181 | { |
182 | if (flags & GNTMAP_contains_pte) |
183 | unmap->host_addr = addr; |
184 | else if (xen_feature(XENFEAT_auto_translated_physmap)) |
185 | unmap->host_addr = __pa(addr); |
186 | else |
187 | unmap->host_addr = addr; |
188 | |
189 | unmap->handle = handle; |
190 | unmap->dev_bus_addr = 0; |
191 | } |
192 | |
193 | int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status); |
194 | int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, |
195 | unsigned long max_nr_gframes, |
196 | void **__shared); |
197 | int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes, |
198 | unsigned long max_nr_gframes, |
199 | grant_status_t **__shared); |
200 | void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); |
201 | |
202 | struct grant_frames { |
203 | xen_pfn_t *pfn; |
204 | unsigned int count; |
205 | void *vaddr; |
206 | }; |
207 | extern struct grant_frames xen_auto_xlat_grant_frames; |
208 | unsigned int gnttab_max_grant_frames(void); |
209 | int gnttab_setup_auto_xlat_frames(phys_addr_t addr); |
210 | void gnttab_free_auto_xlat_frames(void); |
211 | |
212 | #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) |
213 | |
214 | int gnttab_alloc_pages(int nr_pages, struct page **pages); |
215 | void gnttab_free_pages(int nr_pages, struct page **pages); |
216 | |
217 | struct gnttab_page_cache { |
218 | spinlock_t lock; |
219 | #ifdef CONFIG_XEN_UNPOPULATED_ALLOC |
220 | struct page *pages; |
221 | #else |
222 | struct list_head pages; |
223 | #endif |
224 | unsigned int num_pages; |
225 | }; |
226 | |
227 | void gnttab_page_cache_init(struct gnttab_page_cache *cache); |
228 | int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page); |
229 | void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page, |
230 | unsigned int num); |
231 | void gnttab_page_cache_shrink(struct gnttab_page_cache *cache, |
232 | unsigned int num); |
233 | |
234 | #ifdef CONFIG_XEN_GRANT_DMA_ALLOC |
235 | struct gnttab_dma_alloc_args { |
236 | /* Device for which DMA memory will be/was allocated. */ |
237 | struct device *dev; |
238 | /* If set then DMA buffer is coherent and write-combine otherwise. */ |
239 | bool coherent; |
240 | |
241 | int nr_pages; |
242 | struct page **pages; |
243 | xen_pfn_t *frames; |
244 | void *vaddr; |
245 | dma_addr_t dev_bus_addr; |
246 | }; |
247 | |
248 | int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args); |
249 | int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args); |
250 | #endif |
251 | |
252 | int gnttab_pages_set_private(int nr_pages, struct page **pages); |
253 | void gnttab_pages_clear_private(int nr_pages, struct page **pages); |
254 | |
255 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
256 | struct gnttab_map_grant_ref *kmap_ops, |
257 | struct page **pages, unsigned int count); |
258 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, |
259 | struct gnttab_unmap_grant_ref *kunmap_ops, |
260 | struct page **pages, unsigned int count); |
261 | void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); |
262 | int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item); |
263 | |
264 | |
265 | /* Perform a batch of grant map/copy operations. Retry every batch slot |
266 | * for which the hypervisor returns GNTST_eagain. This is typically due |
267 | * to paged out target frames. |
268 | * |
269 | * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. |
270 | * |
271 | * Return value in each iand every status field of the batch guaranteed |
272 | * to not be GNTST_eagain. |
273 | */ |
274 | void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); |
275 | void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); |
276 | |
277 | |
278 | struct xen_page_foreign { |
279 | domid_t domid; |
280 | grant_ref_t gref; |
281 | }; |
282 | |
283 | static inline struct xen_page_foreign *xen_page_foreign(struct page *page) |
284 | { |
285 | if (!PageForeign(page)) |
286 | return NULL; |
287 | #if BITS_PER_LONG < 64 |
288 | return (struct xen_page_foreign *)page->private; |
289 | #else |
290 | BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG); |
291 | return (struct xen_page_foreign *)&page->private; |
292 | #endif |
293 | } |
294 | |
295 | /* Split Linux page in chunk of the size of the grant and call fn |
296 | * |
297 | * Parameters of fn: |
298 | * gfn: guest frame number |
299 | * offset: offset in the grant |
300 | * len: length of the data in the grant. |
301 | * data: internal information |
302 | */ |
303 | typedef void (*xen_grant_fn_t)(unsigned long gfn, unsigned int offset, |
304 | unsigned int len, void *data); |
305 | |
306 | void gnttab_foreach_grant_in_range(struct page *page, |
307 | unsigned int offset, |
308 | unsigned int len, |
309 | xen_grant_fn_t fn, |
310 | void *data); |
311 | |
312 | /* Helper to get to call fn only on the first "grant chunk" */ |
313 | static inline void gnttab_for_one_grant(struct page *page, unsigned int offset, |
314 | unsigned len, xen_grant_fn_t fn, |
315 | void *data) |
316 | { |
317 | /* The first request is limited to the size of one grant */ |
318 | len = min_t(unsigned int, XEN_PAGE_SIZE - (offset & ~XEN_PAGE_MASK), |
319 | len); |
320 | |
321 | gnttab_foreach_grant_in_range(page, offset, len, fn, data); |
322 | } |
323 | |
324 | /* Get @nr_grefs grants from an array of page and call fn for each grant */ |
325 | void gnttab_foreach_grant(struct page **pages, |
326 | unsigned int nr_grefs, |
327 | xen_grant_fn_t fn, |
328 | void *data); |
329 | |
330 | /* Get the number of grant in a specified region |
331 | * |
332 | * start: Offset from the beginning of the first page |
333 | * len: total length of data (can cross multiple page) |
334 | */ |
335 | static inline unsigned int gnttab_count_grant(unsigned int start, |
336 | unsigned int len) |
337 | { |
338 | return XEN_PFN_UP(xen_offset_in_page(start) + len); |
339 | } |
340 | |
341 | #endif /* __ASM_GNTTAB_H__ */ |
342 | |