1 #ifndef __DRM_VMA_MANAGER_H__
2 #define __DRM_VMA_MANAGER_H__
5 * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com>
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:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
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.
26 #include <drm/drm_mm.h>
28 #include <linux/rbtree.h>
29 #include <linux/spinlock.h>
30 #include <linux/types.h>
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
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)
40 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
41 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
46 struct drm_vma_offset_file
{
48 struct drm_file
*vm_tag
;
49 unsigned long vm_count
;
52 struct drm_vma_offset_node
{
54 struct drm_mm_node vm_node
;
55 struct rb_root vm_files
;
59 struct drm_vma_offset_manager
{
61 struct drm_mm vm_addr_space_mm
;
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
);
68 struct drm_vma_offset_node
*drm_vma_offset_lookup_locked(struct drm_vma_offset_manager
*mgr
,
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
);
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
);
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)
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.
93 * Node at exact start address @start.
95 static inline struct drm_vma_offset_node
*
96 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager
*mgr
,
100 struct drm_vma_offset_node
*node
;
102 node
= drm_vma_offset_lookup_locked(mgr
, start
, pages
);
103 return (node
&& node
->vm_node
.start
== start
) ? node
: NULL
;
107 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use
108 * @mgr: Manager object
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().
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.
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.
120 * Note: You're in atomic-context while holding this lock!
122 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager
*mgr
)
124 read_lock(&mgr
->vm_lock
);
128 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use
129 * @mgr: Manager object
131 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information.
133 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager
*mgr
)
135 read_unlock(&mgr
->vm_lock
);
139 * drm_vma_node_reset() - Initialize or reset node object
140 * @node: Node to initialize or reset
142 * Reset a node to its initial state. This must be called before using it with
143 * any VMA offset manager.
145 * This must not be called on an already allocated node, or you will leak
148 static inline void drm_vma_node_reset(struct drm_vma_offset_node
*node
)
150 memset(node
, 0, sizeof(*node
));
151 node
->vm_files
= RB_ROOT
;
152 rwlock_init(&node
->vm_lock
);
156 * drm_vma_node_start() - Return start address for page-based addressing
157 * @node: Node to inspect
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.
166 * Start address of @node for page-based addressing. 0 if the node does not
167 * have an offset allocated.
169 static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node
*node
)
171 return node
->vm_node
.start
;
175 * drm_vma_node_size() - Return size (page-based)
176 * @node: Node to inspect
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
183 * Size of @node as number of pages. 0 if the node does not have an offset
186 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node
*node
)
188 return node
->vm_node
.size
;
192 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps
193 * @node: Linked offset node
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.
200 * Offset of @node for byte-based addressing. 0 if the node does not have an
203 static inline __u64
drm_vma_node_offset_addr(struct drm_vma_offset_node
*node
)
205 return ((__u64
)node
->vm_node
.start
) << PAGE_SHIFT
;
209 * drm_vma_node_unmap() - Unmap offset node
211 * @file_mapping: Address space to unmap @node from
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
217 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove()
218 * is not called on this node concurrently.
220 static inline void drm_vma_node_unmap(struct drm_vma_offset_node
*node
,
221 struct address_space
*file_mapping
)
223 if (drm_mm_node_allocated(&node
->vm_node
))
224 unmap_mapping_range(file_mapping
,
225 drm_vma_node_offset_addr(node
),
226 drm_vma_node_size(node
) << PAGE_SHIFT
, 1);
230 * drm_vma_node_verify_access() - Access verification helper for TTM
232 * @tag: Tag of file to check
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.
239 * 0 if access is granted, -EACCES otherwise.
241 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node
*node
,
242 struct drm_file
*tag
)
244 return drm_vma_node_is_allowed(node
, tag
) ? 0 : -EACCES
;
247 #endif /* __DRM_VMA_MANAGER_H__ */