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 struct drm_file; 33 34 struct drm_vma_offset_file { 35 struct rb_node vm_rb; 36 struct drm_file *vm_tag; 37 unsigned long vm_count; 38 }; 39 40 struct drm_vma_offset_node { 41 rwlock_t vm_lock; 42 struct drm_mm_node vm_node; 43 struct rb_root vm_files; 44 }; 45 46 struct drm_vma_offset_manager { 47 rwlock_t vm_lock; 48 struct drm_mm vm_addr_space_mm; 49 }; 50 51 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, 52 unsigned long page_offset, unsigned long size); 53 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); 54 55 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 56 unsigned long start, 57 unsigned long pages); 58 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 59 struct drm_vma_offset_node *node, unsigned long pages); 60 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 61 struct drm_vma_offset_node *node); 62 63 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); 64 void drm_vma_node_revoke(struct drm_vma_offset_node *node, 65 struct drm_file *tag); 66 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 67 struct drm_file *tag); 68 69 /** 70 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address 71 * @mgr: Manager object 72 * @start: Start address (page-based, not byte-based) 73 * @pages: Size of object (page-based) 74 * 75 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. 76 * It only returns the exact object with the given start address. 77 * 78 * RETURNS: 79 * Node at exact start address @start. 80 */ 81 static inline struct drm_vma_offset_node * 82 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 83 unsigned long start, 84 unsigned long pages) 85 { 86 struct drm_vma_offset_node *node; 87 88 node = drm_vma_offset_lookup_locked(mgr, start, pages); 89 return (node && node->vm_node.start == start) ? node : NULL; 90 } 91 92 /** 93 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 94 * @mgr: Manager object 95 * 96 * Lock VMA manager for extended lookups. Only locked VMA function calls 97 * are allowed while holding this lock. All other contexts are blocked from VMA 98 * until the lock is released via drm_vma_offset_unlock_lookup(). 99 * 100 * Use this if you need to take a reference to the objects returned by 101 * drm_vma_offset_lookup_locked() before releasing this lock again. 102 * 103 * This lock must not be used for anything else than extended lookups. You must 104 * not call any other VMA helpers while holding this lock. 105 * 106 * Note: You're in atomic-context while holding this lock! 107 */ 108 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 109 { 110 read_lock(&mgr->vm_lock); 111 } 112 113 /** 114 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 115 * @mgr: Manager object 116 * 117 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 118 */ 119 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 120 { 121 read_unlock(&mgr->vm_lock); 122 } 123 124 /** 125 * drm_vma_node_reset() - Initialize or reset node object 126 * @node: Node to initialize or reset 127 * 128 * Reset a node to its initial state. This must be called before using it with 129 * any VMA offset manager. 130 * 131 * This must not be called on an already allocated node, or you will leak 132 * memory. 133 */ 134 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 135 { 136 memset(node, 0, sizeof(*node)); 137 node->vm_files = RB_ROOT; 138 rwlock_init(&node->vm_lock); 139 } 140 141 /** 142 * drm_vma_node_start() - Return start address for page-based addressing 143 * @node: Node to inspect 144 * 145 * Return the start address of the given node. This can be used as offset into 146 * the linear VM space that is provided by the VMA offset manager. Note that 147 * this can only be used for page-based addressing. If you need a proper offset 148 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 149 * drm_vma_node_offset_addr() helper instead. 150 * 151 * RETURNS: 152 * Start address of @node for page-based addressing. 0 if the node does not 153 * have an offset allocated. 154 */ 155 static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node) 156 { 157 return node->vm_node.start; 158 } 159 160 /** 161 * drm_vma_node_size() - Return size (page-based) 162 * @node: Node to inspect 163 * 164 * Return the size as number of pages for the given node. This is the same size 165 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 166 * node, this is 0. 167 * 168 * RETURNS: 169 * Size of @node as number of pages. 0 if the node does not have an offset 170 * allocated. 171 */ 172 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 173 { 174 return node->vm_node.size; 175 } 176 177 /** 178 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 179 * @node: Linked offset node 180 * 181 * Same as drm_vma_node_start() but returns the address as a valid offset that 182 * can be used for user-space mappings during mmap(). 183 * This must not be called on unlinked nodes. 184 * 185 * RETURNS: 186 * Offset of @node for byte-based addressing. 0 if the node does not have an 187 * object allocated. 188 */ 189 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 190 { 191 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 192 } 193 194 /** 195 * drm_vma_node_unmap() - Unmap offset node 196 * @node: Offset node 197 * @file_mapping: Address space to unmap @node from 198 * 199 * Unmap all userspace mappings for a given offset node. The mappings must be 200 * associated with the @file_mapping address-space. If no offset exists 201 * nothing is done. 202 * 203 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 204 * is not called on this node concurrently. 205 */ 206 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 207 struct address_space *file_mapping) 208 { 209 if (drm_mm_node_allocated(&node->vm_node)) 210 unmap_mapping_range(file_mapping, 211 drm_vma_node_offset_addr(node), 212 drm_vma_node_size(node) << PAGE_SHIFT, 1); 213 } 214 215 /** 216 * drm_vma_node_verify_access() - Access verification helper for TTM 217 * @node: Offset node 218 * @tag: Tag of file to check 219 * 220 * This checks whether @tag is granted access to @node. It is the same as 221 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 222 * verify_access() callbacks. 223 * 224 * RETURNS: 225 * 0 if access is granted, -EACCES otherwise. 226 */ 227 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 228 struct drm_file *tag) 229 { 230 return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; 231 } 232 233 #endif /* __DRM_VMA_MANAGER_H__ */ 234