drm_vma_manager.h

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#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);
 
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;
}
 
static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr)
{
    read_lock(&mgr->vm_lock);
}
 
static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr)
{
    read_unlock(&mgr->vm_lock);
}
 
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);
}
 
static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node)
{
    return node->vm_node.start;
}
 
static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node)
{
    return node->vm_node.size;
}
 
static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node)
{
    return ((__u64)node->vm_node.start) << PAGE_SHIFT;
}
 
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);
}
 
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__ */