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_vma_offset_file { 34 struct rb_node vm_rb; 35 struct file *vm_filp; 36 unsigned long vm_count; 37 }; 38 39 struct drm_vma_offset_node { 40 struct lock vm_lock; 41 struct drm_mm_node vm_node; 42 struct rb_node vm_rb; 43 struct rb_root vm_files; 44 }; 45 46 struct drm_vma_offset_manager { 47 struct lock vm_lock; 48 struct rb_root vm_addr_space_rb; 49 struct drm_mm vm_addr_space_mm; 50 }; 51 52 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, 53 unsigned long page_offset, unsigned long size); 54 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); 55 56 struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr, 57 unsigned long start, 58 unsigned long pages); 59 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 60 unsigned long start, 61 unsigned long pages); 62 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 63 struct drm_vma_offset_node *node, unsigned long pages); 64 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 65 struct drm_vma_offset_node *node); 66 67 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp); 68 void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp); 69 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 70 struct file *filp); 71 72 /** 73 * drm_vma_offset_exact_lookup() - 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() 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(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(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 * Example: 112 * drm_vma_offset_lock_lookup(mgr); 113 * node = drm_vma_offset_lookup_locked(mgr); 114 * if (node) 115 * kref_get_unless_zero(container_of(node, sth, entr)); 116 * drm_vma_offset_unlock_lookup(mgr); 117 */ 118 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 119 { 120 lockmgr(&mgr->vm_lock, LK_EXCLUSIVE); 121 } 122 123 /** 124 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 125 * @mgr: Manager object 126 * 127 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 128 */ 129 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 130 { 131 lockmgr(&mgr->vm_lock, LK_RELEASE); 132 } 133 134 /** 135 * drm_vma_node_reset() - Initialize or reset node object 136 * @node: Node to initialize or reset 137 * 138 * Reset a node to its initial state. This must be called before using it with 139 * any VMA offset manager. 140 * 141 * This must not be called on an already allocated node, or you will leak 142 * memory. 143 */ 144 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 145 { 146 memset(node, 0, sizeof(*node)); 147 node->vm_files = RB_ROOT; 148 lockinit(&node->vm_lock, "vmlock", 0, LK_CANRECURSE); 149 } 150 151 /** 152 * drm_vma_node_start() - Return start address for page-based addressing 153 * @node: Node to inspect 154 * 155 * Return the start address of the given node. This can be used as offset into 156 * the linear VM space that is provided by the VMA offset manager. Note that 157 * this can only be used for page-based addressing. If you need a proper offset 158 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 159 * drm_vma_node_offset_addr() helper instead. 160 * 161 * RETURNS: 162 * Start address of @node for page-based addressing. 0 if the node does not 163 * have an offset allocated. 164 */ 165 static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) 166 { 167 return node->vm_node.start; 168 } 169 170 /** 171 * drm_vma_node_size() - Return size (page-based) 172 * @node: Node to inspect 173 * 174 * Return the size as number of pages for the given node. This is the same size 175 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 176 * node, this is 0. 177 * 178 * RETURNS: 179 * Size of @node as number of pages. 0 if the node does not have an offset 180 * allocated. 181 */ 182 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 183 { 184 return node->vm_node.size; 185 } 186 187 /** 188 * drm_vma_node_has_offset() - Check whether node is added to offset manager 189 * @node: Node to be checked 190 * 191 * RETURNS: 192 * true iff the node was previously allocated an offset and added to 193 * an vma offset manager. 194 */ 195 static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) 196 { 197 return drm_mm_node_allocated(&node->vm_node); 198 } 199 200 /** 201 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 202 * @node: Linked offset node 203 * 204 * Same as drm_vma_node_start() but returns the address as a valid offset that 205 * can be used for user-space mappings during mmap(). 206 * This must not be called on unlinked nodes. 207 * 208 * RETURNS: 209 * Offset of @node for byte-based addressing. 0 if the node does not have an 210 * object allocated. 211 */ 212 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 213 { 214 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 215 } 216 217 #if 0 218 /** 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 225 * 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 */ 230 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 231 struct address_space *file_mapping) 232 { 233 if (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 #endif 239 240 /** 241 * drm_vma_node_verify_access() - Access verification helper for TTM 242 * @node: Offset node 243 * @filp: Open-file 244 * 245 * This checks whether @filp is granted access to @node. It is the same as 246 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 247 * verify_access() callbacks. 248 * 249 * RETURNS: 250 * 0 if access is granted, -EACCES otherwise. 251 */ 252 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 253 struct file *filp) 254 { 255 return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES; 256 } 257 258 #endif /* __DRM_VMA_MANAGER_H__ */ 259