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fe3078fa DH |
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> | |
88d7ebe5 | 27 | #include <linux/fs.h> |
51335df9 | 28 | #include <linux/mm.h> |
fe3078fa DH |
29 | #include <linux/module.h> |
30 | #include <linux/rbtree.h> | |
31 | #include <linux/spinlock.h> | |
32 | #include <linux/types.h> | |
33 | ||
88d7ebe5 DH |
34 | struct drm_vma_offset_file { |
35 | struct rb_node vm_rb; | |
36 | struct file *vm_filp; | |
37 | unsigned long vm_count; | |
38 | }; | |
39 | ||
fe3078fa | 40 | struct drm_vma_offset_node { |
88d7ebe5 | 41 | rwlock_t vm_lock; |
fe3078fa DH |
42 | struct drm_mm_node vm_node; |
43 | struct rb_node vm_rb; | |
88d7ebe5 | 44 | struct rb_root vm_files; |
fe3078fa DH |
45 | }; |
46 | ||
47 | struct drm_vma_offset_manager { | |
48 | rwlock_t vm_lock; | |
49 | struct rb_root vm_addr_space_rb; | |
50 | struct drm_mm vm_addr_space_mm; | |
51 | }; | |
52 | ||
53 | void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, | |
54 | unsigned long page_offset, unsigned long size); | |
55 | void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); | |
56 | ||
57 | struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr, | |
58 | unsigned long start, | |
59 | unsigned long pages); | |
60 | struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, | |
61 | unsigned long start, | |
62 | unsigned long pages); | |
63 | int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, | |
64 | struct drm_vma_offset_node *node, unsigned long pages); | |
65 | void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, | |
66 | struct drm_vma_offset_node *node); | |
67 | ||
88d7ebe5 DH |
68 | int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp); |
69 | void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp); | |
70 | bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, | |
71 | struct file *filp); | |
72 | ||
fe3078fa DH |
73 | /** |
74 | * drm_vma_offset_exact_lookup() - Look up node by exact address | |
75 | * @mgr: Manager object | |
76 | * @start: Start address (page-based, not byte-based) | |
77 | * @pages: Size of object (page-based) | |
78 | * | |
79 | * Same as drm_vma_offset_lookup() but does not allow any offset into the node. | |
80 | * It only returns the exact object with the given start address. | |
81 | * | |
82 | * RETURNS: | |
83 | * Node at exact start address @start. | |
84 | */ | |
85 | static inline struct drm_vma_offset_node * | |
86 | drm_vma_offset_exact_lookup(struct drm_vma_offset_manager *mgr, | |
87 | unsigned long start, | |
88 | unsigned long pages) | |
89 | { | |
90 | struct drm_vma_offset_node *node; | |
91 | ||
92 | node = drm_vma_offset_lookup(mgr, start, pages); | |
93 | return (node && node->vm_node.start == start) ? node : NULL; | |
94 | } | |
95 | ||
96 | /** | |
97 | * drm_vma_offset_lock_lookup() - Lock lookup for extended private use | |
98 | * @mgr: Manager object | |
99 | * | |
100 | * Lock VMA manager for extended lookups. Only *_locked() VMA function calls | |
101 | * are allowed while holding this lock. All other contexts are blocked from VMA | |
102 | * until the lock is released via drm_vma_offset_unlock_lookup(). | |
103 | * | |
104 | * Use this if you need to take a reference to the objects returned by | |
105 | * drm_vma_offset_lookup_locked() before releasing this lock again. | |
106 | * | |
107 | * This lock must not be used for anything else than extended lookups. You must | |
108 | * not call any other VMA helpers while holding this lock. | |
109 | * | |
110 | * Note: You're in atomic-context while holding this lock! | |
111 | * | |
112 | * Example: | |
113 | * drm_vma_offset_lock_lookup(mgr); | |
114 | * node = drm_vma_offset_lookup_locked(mgr); | |
115 | * if (node) | |
116 | * kref_get_unless_zero(container_of(node, sth, entr)); | |
117 | * drm_vma_offset_unlock_lookup(mgr); | |
118 | */ | |
119 | static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) | |
120 | { | |
121 | read_lock(&mgr->vm_lock); | |
122 | } | |
123 | ||
124 | /** | |
125 | * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use | |
126 | * @mgr: Manager object | |
127 | * | |
128 | * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. | |
129 | */ | |
130 | static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) | |
131 | { | |
132 | read_unlock(&mgr->vm_lock); | |
133 | } | |
134 | ||
135 | /** | |
136 | * drm_vma_node_reset() - Initialize or reset node object | |
137 | * @node: Node to initialize or reset | |
138 | * | |
88d7ebe5 DH |
139 | * Reset a node to its initial state. This must be called before using it with |
140 | * any VMA offset manager. | |
fe3078fa DH |
141 | * |
142 | * This must not be called on an already allocated node, or you will leak | |
143 | * memory. | |
144 | */ | |
145 | static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) | |
146 | { | |
147 | memset(node, 0, sizeof(*node)); | |
88d7ebe5 DH |
148 | node->vm_files = RB_ROOT; |
149 | rwlock_init(&node->vm_lock); | |
fe3078fa DH |
150 | } |
151 | ||
152 | /** | |
153 | * drm_vma_node_start() - Return start address for page-based addressing | |
154 | * @node: Node to inspect | |
155 | * | |
156 | * Return the start address of the given node. This can be used as offset into | |
157 | * the linear VM space that is provided by the VMA offset manager. Note that | |
158 | * this can only be used for page-based addressing. If you need a proper offset | |
159 | * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the | |
160 | * drm_vma_node_offset_addr() helper instead. | |
161 | * | |
162 | * RETURNS: | |
163 | * Start address of @node for page-based addressing. 0 if the node does not | |
164 | * have an offset allocated. | |
165 | */ | |
166 | static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) | |
167 | { | |
168 | return node->vm_node.start; | |
169 | } | |
170 | ||
171 | /** | |
172 | * drm_vma_node_size() - Return size (page-based) | |
173 | * @node: Node to inspect | |
174 | * | |
175 | * Return the size as number of pages for the given node. This is the same size | |
176 | * that was passed to drm_vma_offset_add(). If no offset is allocated for the | |
177 | * node, this is 0. | |
178 | * | |
179 | * RETURNS: | |
180 | * Size of @node as number of pages. 0 if the node does not have an offset | |
181 | * allocated. | |
182 | */ | |
183 | static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) | |
184 | { | |
185 | return node->vm_node.size; | |
186 | } | |
187 | ||
188 | /** | |
189 | * drm_vma_node_has_offset() - Check whether node is added to offset manager | |
190 | * @node: Node to be checked | |
191 | * | |
192 | * RETURNS: | |
193 | * true iff the node was previously allocated an offset and added to | |
194 | * an vma offset manager. | |
195 | */ | |
196 | static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) | |
197 | { | |
198 | return drm_mm_node_allocated(&node->vm_node); | |
199 | } | |
200 | ||
201 | /** | |
202 | * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps | |
203 | * @node: Linked offset node | |
204 | * | |
205 | * Same as drm_vma_node_start() but returns the address as a valid offset that | |
206 | * can be used for user-space mappings during mmap(). | |
207 | * This must not be called on unlinked nodes. | |
208 | * | |
209 | * RETURNS: | |
210 | * Offset of @node for byte-based addressing. 0 if the node does not have an | |
211 | * object allocated. | |
212 | */ | |
213 | static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) | |
214 | { | |
215 | return ((__u64)node->vm_node.start) << PAGE_SHIFT; | |
216 | } | |
217 | ||
51335df9 DH |
218 | /** |
219 | * drm_vma_node_unmap() - Unmap offset node | |
220 | * @node: Offset node | |
221 | * @file_mapping: Address space to unmap @node from | |
222 | * | |
223 | * Unmap all userspace mappings for a given offset node. The mappings must be | |
224 | * associated with the @file_mapping address-space. If no offset exists or | |
225 | * the address-space is invalid, nothing is done. | |
226 | * | |
227 | * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() | |
228 | * is not called on this node concurrently. | |
229 | */ | |
230 | static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, | |
231 | struct address_space *file_mapping) | |
232 | { | |
233 | if (file_mapping && drm_vma_node_has_offset(node)) | |
234 | unmap_mapping_range(file_mapping, | |
235 | drm_vma_node_offset_addr(node), | |
236 | drm_vma_node_size(node) << PAGE_SHIFT, 1); | |
237 | } | |
238 | ||
88d7ebe5 DH |
239 | /** |
240 | * drm_vma_node_verify_access() - Access verification helper for TTM | |
241 | * @node: Offset node | |
242 | * @filp: Open-file | |
243 | * | |
244 | * This checks whether @filp is granted access to @node. It is the same as | |
245 | * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM | |
246 | * verify_access() callbacks. | |
247 | * | |
248 | * RETURNS: | |
249 | * 0 if access is granted, -EACCES otherwise. | |
250 | */ | |
251 | static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, | |
252 | struct file *filp) | |
253 | { | |
254 | return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES; | |
255 | } | |
256 | ||
fe3078fa | 257 | #endif /* __DRM_VMA_MANAGER_H__ */ |