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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 : : bool readonly:1;
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 : : void drm_vma_node_revoke(struct drm_vma_offset_node *node,
78 : : struct drm_file *tag);
79 : : bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,
80 : : struct drm_file *tag);
81 : :
82 : : /**
83 : : * drm_vma_offset_exact_lookup_locked() - Look up node by exact address
84 : : * @mgr: Manager object
85 : : * @start: Start address (page-based, not byte-based)
86 : : * @pages: Size of object (page-based)
87 : : *
88 : : * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node.
89 : : * It only returns the exact object with the given start address.
90 : : *
91 : : * RETURNS:
92 : : * Node at exact start address @start.
93 : : */
94 : : static inline struct drm_vma_offset_node *
95 : 0 : drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr,
96 : : unsigned long start,
97 : : unsigned long pages)
98 : : {
99 : 0 : struct drm_vma_offset_node *node;
100 : :
101 : 0 : node = drm_vma_offset_lookup_locked(mgr, start, pages);
102 [ # # # # ]: 0 : return (node && node->vm_node.start == start) ? node : NULL;
103 : : }
104 : :
105 : : /**
106 : : * drm_vma_offset_lock_lookup() - Lock lookup for extended private use
107 : : * @mgr: Manager object
108 : : *
109 : : * Lock VMA manager for extended lookups. Only locked VMA function calls
110 : : * are allowed while holding this lock. All other contexts are blocked from VMA
111 : : * until the lock is released via drm_vma_offset_unlock_lookup().
112 : : *
113 : : * Use this if you need to take a reference to the objects returned by
114 : : * drm_vma_offset_lookup_locked() before releasing this lock again.
115 : : *
116 : : * This lock must not be used for anything else than extended lookups. You must
117 : : * not call any other VMA helpers while holding this lock.
118 : : *
119 : : * Note: You're in atomic-context while holding this lock!
120 : : */
121 : 0 : static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr)
122 : : {
123 : 0 : read_lock(&mgr->vm_lock);
124 : : }
125 : :
126 : : /**
127 : : * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use
128 : : * @mgr: Manager object
129 : : *
130 : : * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information.
131 : : */
132 : 0 : static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr)
133 : : {
134 : 0 : read_unlock(&mgr->vm_lock);
135 : : }
136 : :
137 : : /**
138 : : * drm_vma_node_reset() - Initialize or reset node object
139 : : * @node: Node to initialize or reset
140 : : *
141 : : * Reset a node to its initial state. This must be called before using it with
142 : : * any VMA offset manager.
143 : : *
144 : : * This must not be called on an already allocated node, or you will leak
145 : : * memory.
146 : : */
147 : 0 : static inline void drm_vma_node_reset(struct drm_vma_offset_node *node)
148 : : {
149 : 0 : memset(node, 0, sizeof(*node));
150 : 0 : node->vm_files = RB_ROOT;
151 : 0 : rwlock_init(&node->vm_lock);
152 : : }
153 : :
154 : : /**
155 : : * drm_vma_node_start() - Return start address for page-based addressing
156 : : * @node: Node to inspect
157 : : *
158 : : * Return the start address of the given node. This can be used as offset into
159 : : * the linear VM space that is provided by the VMA offset manager. Note that
160 : : * this can only be used for page-based addressing. If you need a proper offset
161 : : * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the
162 : : * drm_vma_node_offset_addr() helper instead.
163 : : *
164 : : * RETURNS:
165 : : * Start address of @node for page-based addressing. 0 if the node does not
166 : : * have an offset allocated.
167 : : */
168 : 0 : static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node)
169 : : {
170 [ # # ]: 0 : return node->vm_node.start;
171 : : }
172 : :
173 : : /**
174 : : * drm_vma_node_size() - Return size (page-based)
175 : : * @node: Node to inspect
176 : : *
177 : : * Return the size as number of pages for the given node. This is the same size
178 : : * that was passed to drm_vma_offset_add(). If no offset is allocated for the
179 : : * node, this is 0.
180 : : *
181 : : * RETURNS:
182 : : * Size of @node as number of pages. 0 if the node does not have an offset
183 : : * allocated.
184 : : */
185 : 0 : static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node)
186 : : {
187 : 0 : return node->vm_node.size;
188 : : }
189 : :
190 : : /**
191 : : * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps
192 : : * @node: Linked offset node
193 : : *
194 : : * Same as drm_vma_node_start() but returns the address as a valid offset that
195 : : * can be used for user-space mappings during mmap().
196 : : * This must not be called on unlinked nodes.
197 : : *
198 : : * RETURNS:
199 : : * Offset of @node for byte-based addressing. 0 if the node does not have an
200 : : * object allocated.
201 : : */
202 : 0 : static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node)
203 : : {
204 : 0 : return ((__u64)node->vm_node.start) << PAGE_SHIFT;
205 : : }
206 : :
207 : : /**
208 : : * drm_vma_node_unmap() - Unmap offset node
209 : : * @node: Offset node
210 : : * @file_mapping: Address space to unmap @node from
211 : : *
212 : : * Unmap all userspace mappings for a given offset node. The mappings must be
213 : : * associated with the @file_mapping address-space. If no offset exists
214 : : * nothing is done.
215 : : *
216 : : * This call is unlocked. The caller must guarantee that drm_vma_offset_remove()
217 : : * is not called on this node concurrently.
218 : : */
219 : 0 : static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node,
220 : : struct address_space *file_mapping)
221 : : {
222 [ # # ]: 0 : if (drm_mm_node_allocated(&node->vm_node))
223 : 0 : unmap_mapping_range(file_mapping,
224 : 0 : drm_vma_node_offset_addr(node),
225 : 0 : drm_vma_node_size(node) << PAGE_SHIFT, 1);
226 : 0 : }
227 : :
228 : : /**
229 : : * drm_vma_node_verify_access() - Access verification helper for TTM
230 : : * @node: Offset node
231 : : * @tag: Tag of file to check
232 : : *
233 : : * This checks whether @tag is granted access to @node. It is the same as
234 : : * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM
235 : : * verify_access() callbacks.
236 : : *
237 : : * RETURNS:
238 : : * 0 if access is granted, -EACCES otherwise.
239 : : */
240 : : static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node,
241 : : struct drm_file *tag)
242 : : {
243 : : return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES;
244 : : }
245 : :
246 : : #endif /* __DRM_VMA_MANAGER_H__ */
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