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/module.h>
29 #include <linux/rbtree.h>
30 #include <linux/spinlock.h>
31 #include <linux/types.h>
35 struct drm_vma_offset_file {
37 struct drm_file *vm_tag;
38 unsigned long vm_count;
41 struct drm_vma_offset_node {
43 struct drm_mm_node vm_node;
45 struct rb_root vm_files;
48 struct drm_vma_offset_manager {
50 struct rb_root vm_addr_space_rb;
51 struct drm_mm vm_addr_space_mm;
54 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr,
55 unsigned long page_offset, unsigned long size);
56 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr);
58 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr,
61 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr,
62 struct drm_vma_offset_node *node, unsigned long pages);
63 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr,
64 struct drm_vma_offset_node *node);
66 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag);
67 void drm_vma_node_revoke(struct drm_vma_offset_node *node,
68 struct drm_file *tag);
69 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,
70 struct drm_file *tag);
73 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address
74 * @mgr: Manager object
75 * @start: Start address (page-based, not byte-based)
76 * @pages: Size of object (page-based)
78 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node.
79 * It only returns the exact object with the given start address.
82 * Node at exact start address @start.
84 static inline struct drm_vma_offset_node *
85 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr,
89 struct drm_vma_offset_node *node;
91 node = drm_vma_offset_lookup_locked(mgr, start, pages);
92 return (node && node->vm_node.start == start) ? node : NULL;
96 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use
97 * @mgr: Manager object
99 * Lock VMA manager for extended lookups. Only locked VMA function calls
100 * are allowed while holding this lock. All other contexts are blocked from VMA
101 * until the lock is released via drm_vma_offset_unlock_lookup().
103 * Use this if you need to take a reference to the objects returned by
104 * drm_vma_offset_lookup_locked() before releasing this lock again.
106 * This lock must not be used for anything else than extended lookups. You must
107 * not call any other VMA helpers while holding this lock.
109 * Note: You're in atomic-context while holding this lock!
111 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr)
113 lockmgr(&mgr->vm_lock, LK_EXCLUSIVE);
117 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use
118 * @mgr: Manager object
120 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information.
122 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr)
124 lockmgr(&mgr->vm_lock, LK_RELEASE);
128 * drm_vma_node_reset() - Initialize or reset node object
129 * @node: Node to initialize or reset
131 * Reset a node to its initial state. This must be called before using it with
132 * any VMA offset manager.
134 * This must not be called on an already allocated node, or you will leak
137 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node)
139 memset(node, 0, sizeof(*node));
140 node->vm_files = LINUX_RB_ROOT;
141 lockinit(&node->vm_lock, "vmlock", 0, LK_CANRECURSE);
145 * drm_vma_node_start() - Return start address for page-based addressing
146 * @node: Node to inspect
148 * Return the start address of the given node. This can be used as offset into
149 * the linear VM space that is provided by the VMA offset manager. Note that
150 * this can only be used for page-based addressing. If you need a proper offset
151 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the
152 * drm_vma_node_offset_addr() helper instead.
155 * Start address of @node for page-based addressing. 0 if the node does not
156 * have an offset allocated.
158 static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node)
160 return node->vm_node.start;
164 * drm_vma_node_size() - Return size (page-based)
165 * @node: Node to inspect
167 * Return the size as number of pages for the given node. This is the same size
168 * that was passed to drm_vma_offset_add(). If no offset is allocated for the
172 * Size of @node as number of pages. 0 if the node does not have an offset
175 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node)
177 return node->vm_node.size;
181 * drm_vma_node_has_offset() - Check whether node is added to offset manager
182 * @node: Node to be checked
185 * true iff the node was previously allocated an offset and added to
186 * an vma offset manager.
188 static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node)
190 return drm_mm_node_allocated(&node->vm_node);
194 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps
195 * @node: Linked offset node
197 * Same as drm_vma_node_start() but returns the address as a valid offset that
198 * can be used for user-space mappings during mmap().
199 * This must not be called on unlinked nodes.
202 * Offset of @node for byte-based addressing. 0 if the node does not have an
205 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node)
207 return ((__u64)node->vm_node.start) << PAGE_SHIFT;
212 * drm_vma_node_unmap() - Unmap offset node
214 * @file_mapping: Address space to unmap @node from
216 * Unmap all userspace mappings for a given offset node. The mappings must be
217 * associated with the @file_mapping address-space. If no offset exists
220 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove()
221 * is not called on this node concurrently.
223 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node,
224 struct address_space *file_mapping)
226 if (file_mapping && drm_vma_node_has_offset(node))
227 unmap_mapping_range(file_mapping,
228 drm_vma_node_offset_addr(node),
229 drm_vma_node_size(node) << PAGE_SHIFT, 1);
234 * drm_vma_node_verify_access() - Access verification helper for TTM
236 * @tag: Tag of file to check
238 * This checks whether @tag is granted access to @node. It is the same as
239 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM
240 * verify_access() callbacks.
243 * 0 if access is granted, -EACCES otherwise.
245 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node,
246 struct drm_file *tag)
248 return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES;
251 #endif /* __DRM_VMA_MANAGER_H__ */