1 | #ifndef __DRM_VMA_MANAGER_H__ |
2 | #define __DRM_VMA_MANAGER_H__ |
3 | |
4 | /* |
5 | * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com> |
6 | * |
7 | * Permission is hereby granted, free of charge, to any person obtaining a |
8 | * copy of this software and associated documentation files (the "Software"), |
9 | * to deal in the Software without restriction, including without limitation |
10 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
11 | * and/or sell copies of the Software, and to permit persons to whom the |
12 | * Software is furnished to do so, subject to the following conditions: |
13 | * |
14 | * The above copyright notice and this permission notice shall be included in |
15 | * all copies or substantial portions of the Software. |
16 | * |
17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
20 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
21 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
22 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
23 | * OTHER DEALINGS IN THE SOFTWARE. |
24 | */ |
25 | |
26 | #include <drm/drm_mm.h> |
27 | #include <linux/mm.h> |
28 | #include <linux/rbtree.h> |
29 | #include <linux/spinlock.h> |
30 | #include <linux/types.h> |
31 | |
32 | /* We make up offsets for buffer objects so we can recognize them at |
33 | * mmap time. pgoff in mmap is an unsigned long, so we need to make sure |
34 | * that the faked up offset will fit |
35 | */ |
36 | #if BITS_PER_LONG == 64 |
37 | #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) |
38 | #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 256) |
39 | #else |
40 | #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) |
41 | #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) |
42 | #endif |
43 | |
44 | struct drm_file; |
45 | |
46 | struct drm_vma_offset_file { |
47 | struct rb_node vm_rb; |
48 | struct drm_file *vm_tag; |
49 | unsigned long vm_count; |
50 | }; |
51 | |
52 | struct drm_vma_offset_node { |
53 | rwlock_t vm_lock; |
54 | struct drm_mm_node vm_node; |
55 | struct rb_root vm_files; |
56 | void *driver_private; |
57 | }; |
58 | |
59 | struct drm_vma_offset_manager { |
60 | rwlock_t vm_lock; |
61 | struct drm_mm vm_addr_space_mm; |
62 | }; |
63 | |
64 | void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, |
65 | unsigned long page_offset, unsigned long size); |
66 | void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); |
67 | |
68 | struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, |
69 | unsigned long start, |
70 | unsigned long pages); |
71 | int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, |
72 | struct drm_vma_offset_node *node, unsigned long pages); |
73 | void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, |
74 | struct drm_vma_offset_node *node); |
75 | |
76 | int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); |
77 | int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag); |
78 | void drm_vma_node_revoke(struct drm_vma_offset_node *node, |
79 | struct drm_file *tag); |
80 | bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, |
81 | struct drm_file *tag); |
82 | |
83 | /** |
84 | * drm_vma_offset_exact_lookup_locked() - Look up node by exact address |
85 | * @mgr: Manager object |
86 | * @start: Start address (page-based, not byte-based) |
87 | * @pages: Size of object (page-based) |
88 | * |
89 | * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. |
90 | * It only returns the exact object with the given start address. |
91 | * |
92 | * RETURNS: |
93 | * Node at exact start address @start. |
94 | */ |
95 | static inline struct drm_vma_offset_node * |
96 | drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, |
97 | unsigned long start, |
98 | unsigned long pages) |
99 | { |
100 | struct drm_vma_offset_node *node; |
101 | |
102 | node = drm_vma_offset_lookup_locked(mgr, start, pages); |
103 | return (node && node->vm_node.start == start) ? node : NULL; |
104 | } |
105 | |
106 | /** |
107 | * drm_vma_offset_lock_lookup() - Lock lookup for extended private use |
108 | * @mgr: Manager object |
109 | * |
110 | * Lock VMA manager for extended lookups. Only locked VMA function calls |
111 | * are allowed while holding this lock. All other contexts are blocked from VMA |
112 | * until the lock is released via drm_vma_offset_unlock_lookup(). |
113 | * |
114 | * Use this if you need to take a reference to the objects returned by |
115 | * drm_vma_offset_lookup_locked() before releasing this lock again. |
116 | * |
117 | * This lock must not be used for anything else than extended lookups. You must |
118 | * not call any other VMA helpers while holding this lock. |
119 | * |
120 | * Note: You're in atomic-context while holding this lock! |
121 | */ |
122 | static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) |
123 | { |
124 | read_lock(&mgr->vm_lock); |
125 | } |
126 | |
127 | /** |
128 | * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use |
129 | * @mgr: Manager object |
130 | * |
131 | * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. |
132 | */ |
133 | static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) |
134 | { |
135 | read_unlock(&mgr->vm_lock); |
136 | } |
137 | |
138 | /** |
139 | * drm_vma_node_reset() - Initialize or reset node object |
140 | * @node: Node to initialize or reset |
141 | * |
142 | * Reset a node to its initial state. This must be called before using it with |
143 | * any VMA offset manager. |
144 | * |
145 | * This must not be called on an already allocated node, or you will leak |
146 | * memory. |
147 | */ |
148 | static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) |
149 | { |
150 | memset(node, 0, sizeof(*node)); |
151 | node->vm_files = RB_ROOT; |
152 | rwlock_init(&node->vm_lock); |
153 | } |
154 | |
155 | /** |
156 | * drm_vma_node_start() - Return start address for page-based addressing |
157 | * @node: Node to inspect |
158 | * |
159 | * Return the start address of the given node. This can be used as offset into |
160 | * the linear VM space that is provided by the VMA offset manager. Note that |
161 | * this can only be used for page-based addressing. If you need a proper offset |
162 | * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the |
163 | * drm_vma_node_offset_addr() helper instead. |
164 | * |
165 | * RETURNS: |
166 | * Start address of @node for page-based addressing. 0 if the node does not |
167 | * have an offset allocated. |
168 | */ |
169 | static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node) |
170 | { |
171 | return node->vm_node.start; |
172 | } |
173 | |
174 | /** |
175 | * drm_vma_node_size() - Return size (page-based) |
176 | * @node: Node to inspect |
177 | * |
178 | * Return the size as number of pages for the given node. This is the same size |
179 | * that was passed to drm_vma_offset_add(). If no offset is allocated for the |
180 | * node, this is 0. |
181 | * |
182 | * RETURNS: |
183 | * Size of @node as number of pages. 0 if the node does not have an offset |
184 | * allocated. |
185 | */ |
186 | static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) |
187 | { |
188 | return node->vm_node.size; |
189 | } |
190 | |
191 | /** |
192 | * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps |
193 | * @node: Linked offset node |
194 | * |
195 | * Same as drm_vma_node_start() but returns the address as a valid offset that |
196 | * can be used for user-space mappings during mmap(). |
197 | * This must not be called on unlinked nodes. |
198 | * |
199 | * RETURNS: |
200 | * Offset of @node for byte-based addressing. 0 if the node does not have an |
201 | * object allocated. |
202 | */ |
203 | static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) |
204 | { |
205 | return ((__u64)node->vm_node.start) << PAGE_SHIFT; |
206 | } |
207 | |
208 | /** |
209 | * drm_vma_node_unmap() - Unmap offset node |
210 | * @node: Offset node |
211 | * @file_mapping: Address space to unmap @node from |
212 | * |
213 | * Unmap all userspace mappings for a given offset node. The mappings must be |
214 | * associated with the @file_mapping address-space. If no offset exists |
215 | * nothing is done. |
216 | * |
217 | * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() |
218 | * is not called on this node concurrently. |
219 | */ |
220 | static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, |
221 | struct address_space *file_mapping) |
222 | { |
223 | if (drm_mm_node_allocated(node: &node->vm_node)) |
224 | unmap_mapping_range(mapping: file_mapping, |
225 | holebegin: drm_vma_node_offset_addr(node), |
226 | holelen: drm_vma_node_size(node) << PAGE_SHIFT, even_cows: 1); |
227 | } |
228 | |
229 | /** |
230 | * drm_vma_node_verify_access() - Access verification helper for TTM |
231 | * @node: Offset node |
232 | * @tag: Tag of file to check |
233 | * |
234 | * This checks whether @tag is granted access to @node. It is the same as |
235 | * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM |
236 | * verify_access() callbacks. |
237 | * |
238 | * RETURNS: |
239 | * 0 if access is granted, -EACCES otherwise. |
240 | */ |
241 | static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, |
242 | struct drm_file *tag) |
243 | { |
244 | return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; |
245 | } |
246 | |
247 | #endif /* __DRM_VMA_MANAGER_H__ */ |
248 | |