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 struct lock vm_lock; 42 struct drm_mm_node vm_node; 43 struct rb_node vm_rb; 44 struct rb_root vm_files; 45 }; 46 47 struct drm_vma_offset_manager { 48 struct lock vm_lock; 49 struct rb_root vm_addr_space_rb; 50 struct drm_mm vm_addr_space_mm; 51 }; 52 53 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, 54 unsigned long page_offset, unsigned long size); 55 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); 56 57 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 58 unsigned long start, 59 unsigned long pages); 60 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 61 struct drm_vma_offset_node *node, unsigned long pages); 62 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 63 struct drm_vma_offset_node *node); 64 65 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); 66 void drm_vma_node_revoke(struct drm_vma_offset_node *node, 67 struct drm_file *tag); 68 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 69 struct drm_file *tag); 70 71 /** 72 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address 73 * @mgr: Manager object 74 * @start: Start address (page-based, not byte-based) 75 * @pages: Size of object (page-based) 76 * 77 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. 78 * It only returns the exact object with the given start address. 79 * 80 * RETURNS: 81 * Node at exact start address @start. 82 */ 83 static inline struct drm_vma_offset_node * 84 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 85 unsigned long start, 86 unsigned long pages) 87 { 88 struct drm_vma_offset_node *node; 89 90 node = drm_vma_offset_lookup_locked(mgr, start, pages); 91 return (node && node->vm_node.start == start) ? node : NULL; 92 } 93 94 /** 95 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 96 * @mgr: Manager object 97 * 98 * Lock VMA manager for extended lookups. Only locked VMA function calls 99 * are allowed while holding this lock. All other contexts are blocked from VMA 100 * until the lock is released via drm_vma_offset_unlock_lookup(). 101 * 102 * Use this if you need to take a reference to the objects returned by 103 * drm_vma_offset_lookup_locked() before releasing this lock again. 104 * 105 * This lock must not be used for anything else than extended lookups. You must 106 * not call any other VMA helpers while holding this lock. 107 * 108 * Note: You're in atomic-context while holding this lock! 109 */ 110 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 111 { 112 lockmgr(&mgr->vm_lock, LK_EXCLUSIVE); 113 } 114 115 /** 116 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 117 * @mgr: Manager object 118 * 119 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 120 */ 121 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 122 { 123 lockmgr(&mgr->vm_lock, LK_RELEASE); 124 } 125 126 /** 127 * drm_vma_node_reset() - Initialize or reset node object 128 * @node: Node to initialize or reset 129 * 130 * Reset a node to its initial state. This must be called before using it with 131 * any VMA offset manager. 132 * 133 * This must not be called on an already allocated node, or you will leak 134 * memory. 135 */ 136 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 137 { 138 memset(node, 0, sizeof(*node)); 139 node->vm_files = LINUX_RB_ROOT; 140 lockinit(&node->vm_lock, "vmlock", 0, LK_CANRECURSE); 141 } 142 143 /** 144 * drm_vma_node_start() - Return start address for page-based addressing 145 * @node: Node to inspect 146 * 147 * Return the start address of the given node. This can be used as offset into 148 * the linear VM space that is provided by the VMA offset manager. Note that 149 * this can only be used for page-based addressing. If you need a proper offset 150 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 151 * drm_vma_node_offset_addr() helper instead. 152 * 153 * RETURNS: 154 * Start address of @node for page-based addressing. 0 if the node does not 155 * have an offset allocated. 156 */ 157 static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) 158 { 159 return node->vm_node.start; 160 } 161 162 /** 163 * drm_vma_node_size() - Return size (page-based) 164 * @node: Node to inspect 165 * 166 * Return the size as number of pages for the given node. This is the same size 167 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 168 * node, this is 0. 169 * 170 * RETURNS: 171 * Size of @node as number of pages. 0 if the node does not have an offset 172 * allocated. 173 */ 174 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 175 { 176 return node->vm_node.size; 177 } 178 179 /** 180 * drm_vma_node_has_offset() - Check whether node is added to offset manager 181 * @node: Node to be checked 182 * 183 * RETURNS: 184 * true iff the node was previously allocated an offset and added to 185 * an vma offset manager. 186 */ 187 static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) 188 { 189 return drm_mm_node_allocated(&node->vm_node); 190 } 191 192 /** 193 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 194 * @node: Linked offset node 195 * 196 * Same as drm_vma_node_start() but returns the address as a valid offset that 197 * can be used for user-space mappings during mmap(). 198 * This must not be called on unlinked nodes. 199 * 200 * RETURNS: 201 * Offset of @node for byte-based addressing. 0 if the node does not have an 202 * object allocated. 203 */ 204 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 205 { 206 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 207 } 208 209 #if 0 210 /** 211 * drm_vma_node_unmap() - Unmap offset node 212 * @node: Offset node 213 * @file_mapping: Address space to unmap @node from 214 * 215 * Unmap all userspace mappings for a given offset node. The mappings must be 216 * associated with the @file_mapping address-space. If no offset exists 217 * nothing is done. 218 * 219 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 220 * is not called on this node concurrently. 221 */ 222 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 223 struct address_space *file_mapping) 224 { 225 if (file_mapping && drm_vma_node_has_offset(node)) 226 unmap_mapping_range(file_mapping, 227 drm_vma_node_offset_addr(node), 228 drm_vma_node_size(node) << PAGE_SHIFT, 1); 229 } 230 #endif 231 232 /** 233 * drm_vma_node_verify_access() - Access verification helper for TTM 234 * @node: Offset node 235 * @tag: Tag of file to check 236 * 237 * This checks whether @tag is granted access to @node. It is the same as 238 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 239 * verify_access() callbacks. 240 * 241 * RETURNS: 242 * 0 if access is granted, -EACCES otherwise. 243 */ 244 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 245 struct drm_file *tag) 246 { 247 return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; 248 } 249 250 #endif /* __DRM_VMA_MANAGER_H__ */ 251