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/module.h> 29 #include <linux/rbtree.h> 30 #include <linux/spinlock.h> 31 #include <linux/types.h> 32 33 struct drm_file; 34 35 struct drm_vma_offset_file { 36 struct rb_node vm_rb; 37 struct drm_file *vm_tag; 38 unsigned long vm_count; 39 }; 40 41 struct drm_vma_offset_node { 42 struct lock vm_lock; 43 struct drm_mm_node vm_node; 44 struct rb_node vm_rb; 45 struct rb_root vm_files; 46 }; 47 48 struct drm_vma_offset_manager { 49 struct lock vm_lock; 50 struct rb_root vm_addr_space_rb; 51 struct drm_mm vm_addr_space_mm; 52 }; 53 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); 57 58 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 59 unsigned long start, 60 unsigned long pages); 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); 65 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); 71 72 /** 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) 77 * 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. 80 * 81 * RETURNS: 82 * Node at exact start address @start. 83 */ 84 static inline struct drm_vma_offset_node * 85 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 86 unsigned long start, 87 unsigned long pages) 88 { 89 struct drm_vma_offset_node *node; 90 91 node = drm_vma_offset_lookup_locked(mgr, start, pages); 92 return (node && node->vm_node.start == start) ? node : NULL; 93 } 94 95 /** 96 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 97 * @mgr: Manager object 98 * 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(). 102 * 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. 105 * 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. 108 * 109 * Note: You're in atomic-context while holding this lock! 110 */ 111 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 112 { 113 lockmgr(&mgr->vm_lock, LK_EXCLUSIVE); 114 } 115 116 /** 117 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 118 * @mgr: Manager object 119 * 120 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 121 */ 122 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 123 { 124 lockmgr(&mgr->vm_lock, LK_RELEASE); 125 } 126 127 /** 128 * drm_vma_node_reset() - Initialize or reset node object 129 * @node: Node to initialize or reset 130 * 131 * Reset a node to its initial state. This must be called before using it with 132 * any VMA offset manager. 133 * 134 * This must not be called on an already allocated node, or you will leak 135 * memory. 136 */ 137 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 138 { 139 memset(node, 0, sizeof(*node)); 140 node->vm_files = LINUX_RB_ROOT; 141 lockinit(&node->vm_lock, "vmlock", 0, LK_CANRECURSE); 142 } 143 144 /** 145 * drm_vma_node_start() - Return start address for page-based addressing 146 * @node: Node to inspect 147 * 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. 153 * 154 * RETURNS: 155 * Start address of @node for page-based addressing. 0 if the node does not 156 * have an offset allocated. 157 */ 158 static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) 159 { 160 return node->vm_node.start; 161 } 162 163 /** 164 * drm_vma_node_size() - Return size (page-based) 165 * @node: Node to inspect 166 * 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 169 * node, this is 0. 170 * 171 * RETURNS: 172 * Size of @node as number of pages. 0 if the node does not have an offset 173 * allocated. 174 */ 175 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 176 { 177 return node->vm_node.size; 178 } 179 180 /** 181 * drm_vma_node_has_offset() - Check whether node is added to offset manager 182 * @node: Node to be checked 183 * 184 * RETURNS: 185 * true iff the node was previously allocated an offset and added to 186 * an vma offset manager. 187 */ 188 static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) 189 { 190 return drm_mm_node_allocated(&node->vm_node); 191 } 192 193 /** 194 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 195 * @node: Linked offset node 196 * 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. 200 * 201 * RETURNS: 202 * Offset of @node for byte-based addressing. 0 if the node does not have an 203 * object allocated. 204 */ 205 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 206 { 207 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 208 } 209 210 #if 0 211 /** 212 * drm_vma_node_unmap() - Unmap offset node 213 * @node: Offset node 214 * @file_mapping: Address space to unmap @node from 215 * 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 218 * nothing is done. 219 * 220 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 221 * is not called on this node concurrently. 222 */ 223 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 224 struct address_space *file_mapping) 225 { 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); 230 } 231 #endif 232 233 /** 234 * drm_vma_node_verify_access() - Access verification helper for TTM 235 * @node: Offset node 236 * @tag: Tag of file to check 237 * 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. 241 * 242 * RETURNS: 243 * 0 if access is granted, -EACCES otherwise. 244 */ 245 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 246 struct drm_file *tag) 247 { 248 return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; 249 } 250 251 #endif /* __DRM_VMA_MANAGER_H__ */ 252