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Diffstat (limited to 'kernel/include/drm/drm_vma_manager.h')
| -rw-r--r-- | kernel/include/drm/drm_vma_manager.h | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/kernel/include/drm/drm_vma_manager.h b/kernel/include/drm/drm_vma_manager.h new file mode 100644 index 000000000..8cd402c73 --- /dev/null +++ b/kernel/include/drm/drm_vma_manager.h @@ -0,0 +1,257 @@ +#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/fs.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/rbtree.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +struct drm_vma_offset_file { + struct rb_node vm_rb; + struct file *vm_filp; + unsigned long vm_count; +}; + +struct drm_vma_offset_node { + rwlock_t vm_lock; + struct drm_mm_node vm_node; + struct rb_node vm_rb; + struct rb_root vm_files; +}; + +struct drm_vma_offset_manager { + rwlock_t vm_lock; + struct rb_root vm_addr_space_rb; + 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(struct drm_vma_offset_manager *mgr, + unsigned long start, + unsigned long pages); +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 file *filp); +void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp); +bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, + struct file *filp); + +/** + * drm_vma_offset_exact_lookup() - 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() 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(struct drm_vma_offset_manager *mgr, + unsigned long start, + unsigned long pages) +{ + struct drm_vma_offset_node *node; + + node = drm_vma_offset_lookup(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! + * + * Example: + * drm_vma_offset_lock_lookup(mgr); + * node = drm_vma_offset_lookup_locked(mgr); + * if (node) + * kref_get_unless_zero(container_of(node, sth, entr)); + * drm_vma_offset_unlock_lookup(mgr); + */ +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(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_has_offset() - Check whether node is added to offset manager + * @node: Node to be checked + * + * RETURNS: + * true iff the node was previously allocated an offset and added to + * an vma offset manager. + */ +static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) +{ + return drm_mm_node_allocated(&node->vm_node); +} + +/** + * 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_vma_node_has_offset(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 + * @filp: Open-file + * + * This checks whether @filp 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 file *filp) +{ + return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES; +} + +#endif /* __DRM_VMA_MANAGER_H__ */ |