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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
57struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr,
58 unsigned long start,
59 unsigned long pages);
60struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr,
61 unsigned long start,
62 unsigned long pages);
63int drm_vma_offset_add(struct drm_vma_offset_manager *mgr,
64 struct drm_vma_offset_node *node, unsigned long pages);
65void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr,
66 struct drm_vma_offset_node *node);
67
David Herrmann88d7ebe2013-08-25 18:28:57 +020068int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp);
69void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp);
70bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,
71 struct file *filp);
72
David Herrmannfe3078f2013-07-24 21:06:15 +020073/**
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 */
85static inline struct drm_vma_offset_node *
86drm_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 */
119static 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 */
130static 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 *
David Herrmann88d7ebe2013-08-25 18:28:57 +0200139 * Reset a node to its initial state. This must be called before using it with
140 * any VMA offset manager.
David Herrmannfe3078f2013-07-24 21:06:15 +0200141 *
142 * This must not be called on an already allocated node, or you will leak
143 * memory.
144 */
145static inline void drm_vma_node_reset(struct drm_vma_offset_node *node)
146{
147 memset(node, 0, sizeof(*node));
David Herrmann88d7ebe2013-08-25 18:28:57 +0200148 node->vm_files = RB_ROOT;
149 rwlock_init(&node->vm_lock);
David Herrmannfe3078f2013-07-24 21:06:15 +0200150}
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 */
166static 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 */
183static 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 */
196static 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 */
213static 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
David Herrmann51335df2013-07-24 21:10:03 +0200218/**
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 */
230static 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
David Herrmann88d7ebe2013-08-25 18:28:57 +0200239/**
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 */
251static 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
David Herrmannfe3078f2013-07-24 21:06:15 +0200257#endif /* __DRM_VMA_MANAGER_H__ */