// SPDX-License-Identifier: GPL-2.0-only
/*
* Framework for buffer objects that can be shared across devices/subsystems.
*
* Copyright(C) 2011 Linaro Limited. All rights reserved.
* Author: Sumit Semwal <sumit.semwal@ti.com>
*
* Many thanks to linaro-mm-sig list, and specially
* Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and
* Daniel Vetter <daniel@ffwll.ch> for their support in creation and
* refining of this idea.
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/dma-buf.h>
#include <linux/dma-fence.h>
#include <linux/anon_inodes.h>
#include <linux/export.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/poll.h>
#include <linux/dma-resv.h>
#include <linux/mm.h>
#include <linux/mount.h>
#include <linux/pseudo_fs.h>
#include <uapi/linux/dma-buf.h>
#include <uapi/linux/magic.h>
static inline int is_dma_buf_file(struct file *);
struct dma_buf_list {
struct list_head head;
struct mutex lock;
};
static struct dma_buf_list db_list;
static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
{
struct dma_buf *dmabuf;
char name[DMA_BUF_NAME_LEN];
size_t ret = 0;
dmabuf = dentry->d_fsdata;
dma_resv_lock(dmabuf->resv, NULL);
if (dmabuf->name)
ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN);
dma_resv_unlock(dmabuf->resv);
return dynamic_dname(dentry, buffer, buflen, "/%s:%s",
dentry->d_name.name, ret > 0 ? name : "");
}
static const struct dentry_operations dma_buf_dentry_ops = {
.d_dname = dmabuffs_dname,
};
static struct vfsmount *dma_buf_mnt;
static int dma_buf_fs_init_context(struct fs_context *fc)
{
struct pseudo_fs_context *ctx;
ctx = init_pseudo(fc, DMA_BUF_MAGIC);
if (!ctx)
return -ENOMEM;
ctx->dops = &dma_buf_dentry_ops;
return 0;
}
static struct file_system_type dma_buf_fs_type = {
.name = "dmabuf",
.init_fs_context = dma_buf_fs_init_context,
.kill_sb = kill_anon_super,
};
static int dma_buf_release(struct inode *inode, struct file *file)
{
struct dma_buf *dmabuf;
if (!is_dma_buf_file(file))
return -EINVAL</