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David Herrmannfe3078f2013-07-24 21:06:15 +02001#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>
David Herrmann88d7ebe2013-08-25 18:28:57 +020027#include <linux/fs.h>
David Herrmann51335df2013-07-24 21:10:03 +020028#include <linux/mm.h>
David Herrmannfe3078f2013-07-24 21:06:15 +020029#include <linux/module.h>
30#include <linux/rbtree.h>
31#include <linux/spinlock.h>
32#include <linux/types.h>
33
David Herrmann88d7ebe2013-08-25 18:28:57 +020034struct drm_vma_offset_file {
35 struct rb_node vm_rb;
36 struct file *vm_filp;
37 unsigned long vm_count;
38};
39
David Herrmannfe3078f2013-07-24 21:06:15 +020040struct drm_vma_offset_node {
David Herrmann88d7ebe2013-08-25 18:28:57 +020041 rwlock_t vm_lock;
David Herrmannfe3078f2013-07-24 21:06:15 +020042 struct drm_mm_node vm_node;
43 struct rb_node vm_rb;
David Herrmann88d7ebe2013-08-25 18:28:57 +020044 struct rb_root vm_files;
David Herrmannfe3078f2013-07-24 21:06:15 +020045};
46
47struct 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
53void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr,
54 unsigned long page_offset, unsigned long size);
55void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr);
56
David Herrmannfe3078f2013-07-24 21:06:15 +020057struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr,
58 unsigned long start,
59 unsigned long pages);
60int drm_vma_offset_add(struct drm_vma_offset_manager *mgr,
61 struct drm_vma_offset_node *node, unsigned long pages);
62void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr,
63 struct drm_vma_offset_node *node);
64
David Herrmann88d7ebe2013-08-25 18:28:57 +020065int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp);
66void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp);
67bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,
68 struct file *filp);
69
David Herrmannfe3078f2013-07-24 21:06:15 +020070/**
Daniel Vetter2225cfe2015-10-15 11:33:43 +020071 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address
David Herrmannfe3078f2013-07-24 21:06:15 +020072 * @mgr: Manager object
73 * @start: Start address (page-based, not byte-based)
74 * @pages: Size of object (page-based)
75 *
Daniel Vetter2225cfe2015-10-15 11:33:43 +020076 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node.
David Herrmannfe3078f2013-07-24 21:06:15 +020077 * It only returns the exact object with the given start address.
78 *
79 * RETURNS:
80 * Node at exact start address @start.
81 */
82static inline struct drm_vma_offset_node *
Daniel Vetter2225cfe2015-10-15 11:33:43 +020083drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr,
84 unsigned long start,
85 unsigned long pages)
David Herrmannfe3078f2013-07-24 21:06:15 +020086{
87 struct drm_vma_offset_node *node;
88
Daniel Vetter2225cfe2015-10-15 11:33:43 +020089 node = drm_vma_offset_lookup_locked(mgr, start, pages);
David Herrmannfe3078f2013-07-24 21:06:15 +020090 return (node && node->vm_node.start == start) ? node : NULL;
91}
92
93/**
94 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use
95 * @mgr: Manager object
96 *
Lukas Wunnerf71a6d62015-10-12 09:10:33 +020097 * Lock VMA manager for extended lookups. Only locked VMA function calls
David Herrmannfe3078f2013-07-24 21:06:15 +020098 * are allowed while holding this lock. All other contexts are blocked from VMA
99 * until the lock is released via drm_vma_offset_unlock_lookup().
100 *
101 * Use this if you need to take a reference to the objects returned by
102 * drm_vma_offset_lookup_locked() before releasing this lock again.
103 *
104 * This lock must not be used for anything else than extended lookups. You must
105 * not call any other VMA helpers while holding this lock.
106 *
107 * Note: You're in atomic-context while holding this lock!
David Herrmannfe3078f2013-07-24 21:06:15 +0200108 */
109static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr)
110{
111 read_lock(&mgr->vm_lock);
112}
113
114/**
115 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use
116 * @mgr: Manager object
117 *
118 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information.
119 */
120static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr)
121{
122 read_unlock(&mgr->vm_lock);
123}
124
125/**
126 * drm_vma_node_reset() - Initialize or reset node object
127 * @node: Node to initialize or reset
128 *
David Herrmann88d7ebe2013-08-25 18:28:57 +0200129 * Reset a node to its initial state. This must be called before using it with
130 * any VMA offset manager.
David Herrmannfe3078f2013-07-24 21:06:15 +0200131 *
132 * This must not be called on an already allocated node, or you will leak
133 * memory.
134 */
135static inline void drm_vma_node_reset(struct drm_vma_offset_node *node)
136{
137 memset(node, 0, sizeof(*node));
David Herrmann88d7ebe2013-08-25 18:28:57 +0200138 node->vm_files = RB_ROOT;
139 rwlock_init(&node->vm_lock);
David Herrmannfe3078f2013-07-24 21:06:15 +0200140}
141
142/**
143 * drm_vma_node_start() - Return start address for page-based addressing
144 * @node: Node to inspect
145 *
146 * Return the start address of the given node. This can be used as offset into
147 * the linear VM space that is provided by the VMA offset manager. Note that
148 * this can only be used for page-based addressing. If you need a proper offset
149 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the
150 * drm_vma_node_offset_addr() helper instead.
151 *
152 * RETURNS:
153 * Start address of @node for page-based addressing. 0 if the node does not
154 * have an offset allocated.
155 */
156static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node)
157{
158 return node->vm_node.start;
159}
160
161/**
162 * drm_vma_node_size() - Return size (page-based)
163 * @node: Node to inspect
164 *
165 * Return the size as number of pages for the given node. This is the same size
166 * that was passed to drm_vma_offset_add(). If no offset is allocated for the
167 * node, this is 0.
168 *
169 * RETURNS:
170 * Size of @node as number of pages. 0 if the node does not have an offset
171 * allocated.
172 */
173static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node)
174{
175 return node->vm_node.size;
176}
177
178/**
179 * drm_vma_node_has_offset() - Check whether node is added to offset manager
180 * @node: Node to be checked
181 *
182 * RETURNS:
183 * true iff the node was previously allocated an offset and added to
184 * an vma offset manager.
185 */
186static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node)
187{
188 return drm_mm_node_allocated(&node->vm_node);
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 */
203static 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
David Herrmann51335df2013-07-24 21:10:03 +0200208/**
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
David Herrmann44d847b2013-08-13 19:10:30 +0200214 * associated with the @file_mapping address-space. If no offset exists
215 * nothing is done.
David Herrmann51335df2013-07-24 21:10:03 +0200216 *
217 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove()
218 * is not called on this node concurrently.
219 */
220static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node,
221 struct address_space *file_mapping)
222{
David Herrmann44d847b2013-08-13 19:10:30 +0200223 if (drm_vma_node_has_offset(node))
David Herrmann51335df2013-07-24 21:10:03 +0200224 unmap_mapping_range(file_mapping,
225 drm_vma_node_offset_addr(node),
226 drm_vma_node_size(node) << PAGE_SHIFT, 1);
227}
228
David Herrmann88d7ebe2013-08-25 18:28:57 +0200229/**
230 * drm_vma_node_verify_access() - Access verification helper for TTM
231 * @node: Offset node
232 * @filp: Open-file
233 *
234 * This checks whether @filp 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 */
241static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node,
242 struct file *filp)
243{
244 return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES;
245}
246
David Herrmannfe3078f2013-07-24 21:06:15 +0200247#endif /* __DRM_VMA_MANAGER_H__ */