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/fs.h> 28 #include <linux/mm.h> 29 #include <linux/module.h> 30 #include <linux/rbtree.h> 31 #include <linux/spinlock.h> 32 #include <linux/types.h> 33 34 struct drm_vma_offset_file { 35 struct rb_node vm_rb; 36 struct file *vm_filp; 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_node vm_rb; 44 struct rb_root vm_files; 45 }; 46 47 struct 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 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 file *filp); 66 void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp); 67 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 68 struct file *filp); 69 70 /** 71 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address 72 * @mgr: Manager object 73 * @start: Start address (page-based, not byte-based) 74 * @pages: Size of object (page-based) 75 * 76 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. 77 * It only returns the exact object with the given start address. 78 * 79 * RETURNS: 80 * Node at exact start address @start. 81 */ 82 static inline struct drm_vma_offset_node * 83 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 84 unsigned long start, 85 unsigned long pages) 86 { 87 struct drm_vma_offset_node *node; 88 89 node = drm_vma_offset_lookup_locked(mgr, start, pages); 90 return (node && node->vm_node.start == start) ? node : NULL; 91 } 92 93 /** 94 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 95 * @mgr: Manager object 96 * 97 * Lock VMA manager for extended lookups. Only locked VMA function calls 98 * are allowed while holding this lock. All other contexts are blocked from VMA 99 * until the lock is released via drm_vma_offset_unlock_lookup(). 100 * 101 * Use this if you need to take a reference to the objects returned by 102 * drm_vma_offset_lookup_locked() before releasing this lock again. 103 * 104 * This lock must not be used for anything else than extended lookups. You must 105 * not call any other VMA helpers while holding this lock. 106 * 107 * Note: You're in atomic-context while holding this lock! 108 */ 109 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 110 { 111 read_lock(&mgr->vm_lock); 112 } 113 114 /** 115 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 116 * @mgr: Manager object 117 * 118 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 119 */ 120 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 121 { 122 read_unlock(&mgr->vm_lock); 123 } 124 125 /** 126 * drm_vma_node_reset() - Initialize or reset node object 127 * @node: Node to initialize or reset 128 * 129 * Reset a node to its initial state. This must be called before using it with 130 * any VMA offset manager. 131 * 132 * This must not be called on an already allocated node, or you will leak 133 * memory. 134 */ 135 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 136 { 137 memset(node, 0, sizeof(*node)); 138 node->vm_files = RB_ROOT; 139 rwlock_init(&node->vm_lock); 140 } 141 142 /** 143 * drm_vma_node_start() - Return start address for page-based addressing 144 * @node: Node to inspect 145 * 146 * Return the start address of the given node. This can be used as offset into 147 * the linear VM space that is provided by the VMA offset manager. Note that 148 * this can only be used for page-based addressing. If you need a proper offset 149 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 150 * drm_vma_node_offset_addr() helper instead. 151 * 152 * RETURNS: 153 * Start address of @node for page-based addressing. 0 if the node does not 154 * have an offset allocated. 155 */ 156 static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) 157 { 158 return node->vm_node.start; 159 } 160 161 /** 162 * drm_vma_node_size() - Return size (page-based) 163 * @node: Node to inspect 164 * 165 * Return the size as number of pages for the given node. This is the same size 166 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 167 * node, this is 0. 168 * 169 * RETURNS: 170 * Size of @node as number of pages. 0 if the node does not have an offset 171 * allocated. 172 */ 173 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 174 { 175 return node->vm_node.size; 176 } 177 178 /** 179 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 180 * @node: Linked offset node 181 * 182 * Same as drm_vma_node_start() but returns the address as a valid offset that 183 * can be used for user-space mappings during mmap(). 184 * This must not be called on unlinked nodes. 185 * 186 * RETURNS: 187 * Offset of @node for byte-based addressing. 0 if the node does not have an 188 * object allocated. 189 */ 190 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 191 { 192 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 193 } 194 195 /** 196 * drm_vma_node_unmap() - Unmap offset node 197 * @node: Offset node 198 * @file_mapping: Address space to unmap @node from 199 * 200 * Unmap all userspace mappings for a given offset node. The mappings must be 201 * associated with the @file_mapping address-space. If no offset exists 202 * nothing is done. 203 * 204 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 205 * is not called on this node concurrently. 206 */ 207 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 208 struct address_space *file_mapping) 209 { 210 if (drm_mm_node_allocated(&node->vm_node)) 211 unmap_mapping_range(file_mapping, 212 drm_vma_node_offset_addr(node), 213 drm_vma_node_size(node) << PAGE_SHIFT, 1); 214 } 215 216 /** 217 * drm_vma_node_verify_access() - Access verification helper for TTM 218 * @node: Offset node 219 * @filp: Open-file 220 * 221 * This checks whether @filp is granted access to @node. It is the same as 222 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 223 * verify_access() callbacks. 224 * 225 * RETURNS: 226 * 0 if access is granted, -EACCES otherwise. 227 */ 228 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 229 struct file *filp) 230 { 231 return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES; 232 } 233 234 #endif /* __DRM_VMA_MANAGER_H__ */ 235