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