name : drm_vma_manager.h #ifndef __DRM_VMA_MANAGER_H__ #define __DRM_VMA_MANAGER_H__ /* * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com> * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #include <drm/drm_mm.h> #include <linux/mm.h> #include <linux/rbtree.h> #include <linux/spinlock.h> #include <linux/types.h> /* We make up offsets for buffer objects so we can recognize them at * mmap time. pgoff in mmap is an unsigned long, so we need to make sure * that the faked up offset will fit */ #if BITS_PER_LONG == 64 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 256) #else #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) #endif struct drm_file; struct drm_vma_offset_file { struct rb_node vm_rb; struct drm_file *vm_tag; unsigned long vm_count; }; struct drm_vma_offset_node { rwlock_t vm_lock; struct drm_mm_node vm_node; struct rb_root vm_files; void *driver_private; }; struct drm_vma_offset_manager { rwlock_t vm_lock; struct drm_mm vm_addr_space_mm; }; void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, unsigned long page_offset, unsigned long size); void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, unsigned long start, unsigned long pages); int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, struct drm_vma_offset_node *node, unsigned long pages); void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, struct drm_vma_offset_node *node); int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag); void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct drm_file *tag); bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, struct drm_file *tag); /** * drm_vma_offset_exact_lookup_locked() - Look up node by exact address * @mgr: Manager object * @start: Start address (page-based, not byte-based) * @pages: Size of object (page-based) * * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. * It only returns the exact object with the given start address. * * RETURNS: * Node at exact start address @start. */ static inline struct drm_vma_offset_node * drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, unsigned long start, unsigned long pages) { struct drm_vma_offset_node *node; node = drm_vma_offset_lookup_locked(mgr, start, pages); return (node && node->vm_node.start == start) ? node : NULL; } /** * drm_vma_offset_lock_lookup() - Lock lookup for extended private use * @mgr: Manager object * * Lock VMA manager for extended lookups. Only locked VMA function calls * are allowed while holding this lock. All other contexts are blocked from VMA * until the lock is released via drm_vma_offset_unlock_lookup(). * * Use this if you need to take a reference to the objects returned by * drm_vma_offset_lookup_locked() before releasing this lock again. * * This lock must not be used for anything else than extended lookups. You must * not call any other VMA helpers while holding this lock. * * Note: You're in atomic-context while holding this lock! */ static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) { read_lock(&mgr->vm_lock); } /** * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use * @mgr: Manager object * * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. */ static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) { read_unlock(&mgr->vm_lock); } /** * drm_vma_node_reset() - Initialize or reset node object * @node: Node to initialize or reset * * Reset a node to its initial state. This must be called before using it with * any VMA offset manager. * * This must not be called on an already allocated node, or you will leak * memory. */ static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) { memset(node, 0, sizeof(*node)); node->vm_files = RB_ROOT; rwlock_init(&node->vm_lock); } /** * drm_vma_node_start() - Return start address for page-based addressing * @node: Node to inspect * * Return the start address of the given node. This can be used as offset into * the linear VM space that is provided by the VMA offset manager. Note that * this can only be used for page-based addressing. If you need a proper offset * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the * drm_vma_node_offset_addr() helper instead. * * RETURNS: * Start address of @node for page-based addressing. 0 if the node does not * have an offset allocated. */ static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node) { return node->vm_node.start; } /** * drm_vma_node_size() - Return size (page-based) * @node: Node to inspect * * Return the size as number of pages for the given node. This is the same size * that was passed to drm_vma_offset_add(). If no offset is allocated for the * node, this is 0. * * RETURNS: * Size of @node as number of pages. 0 if the node does not have an offset * allocated. */ static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) { return node->vm_node.size; } /** * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps * @node: Linked offset node * * Same as drm_vma_node_start() but returns the address as a valid offset that * can be used for user-space mappings during mmap(). * This must not be called on unlinked nodes. * * RETURNS: * Offset of @node for byte-based addressing. 0 if the node does not have an * object allocated. */ static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) { return ((__u64)node->vm_node.start) << PAGE_SHIFT; } /** * drm_vma_node_unmap() - Unmap offset node * @node: Offset node * @file_mapping: Address space to unmap @node from * * Unmap all userspace mappings for a given offset node. The mappings must be * associated with the @file_mapping address-space. If no offset exists * nothing is done. * * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() * is not called on this node concurrently. */ static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, struct address_space *file_mapping) { if (drm_mm_node_allocated(&node->vm_node)) unmap_mapping_range(file_mapping, drm_vma_node_offset_addr(node), drm_vma_node_size(node) << PAGE_SHIFT, 1); } /** * drm_vma_node_verify_access() - Access verification helper for TTM * @node: Offset node * @tag: Tag of file to check * * This checks whether @tag is granted access to @node. It is the same as * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM * verify_access() callbacks. * * RETURNS: * 0 if access is granted, -EACCES otherwise. */ static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, struct drm_file *tag) { return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; } #endif /* __DRM_VMA_MANAGER_H__ */