+// SPDX-License-Identifier: GPL-2.0-only
/*
* Framework for buffer objects that can be shared across devices/subsystems.
*
* 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.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published by
- * the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/reservation.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 *);
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;
+ mutex_lock(&dmabuf->lock);
+ if (dmabuf->name)
+ ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN);
+ mutex_unlock(&dmabuf->lock);
+
+ 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;
dmabuf = file->private_data;
+ /* check if buffer supports mmap */
+ if (!dmabuf->ops->mmap)
+ return -EINVAL;
+
/* check for overflowing the buffer's size */
if (vma->vm_pgoff + vma_pages(vma) >
dmabuf->size >> PAGE_SHIFT)
return events;
}
+/**
+ * dma_buf_set_name - Set a name to a specific dma_buf to track the usage.
+ * The name of the dma-buf buffer can only be set when the dma-buf is not
+ * attached to any devices. It could theoritically support changing the
+ * name of the dma-buf if the same piece of memory is used for multiple
+ * purpose between different devices.
+ *
+ * @dmabuf [in] dmabuf buffer that will be renamed.
+ * @buf: [in] A piece of userspace memory that contains the name of
+ * the dma-buf.
+ *
+ * Returns 0 on success. If the dma-buf buffer is already attached to
+ * devices, return -EBUSY.
+ *
+ */
+static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf)
+{
+ char *name = strndup_user(buf, DMA_BUF_NAME_LEN);
+ long ret = 0;
+
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ mutex_lock(&dmabuf->lock);
+ if (!list_empty(&dmabuf->attachments)) {
+ ret = -EBUSY;
+ kfree(name);
+ goto out_unlock;
+ }
+ kfree(dmabuf->name);
+ dmabuf->name = name;
+
+out_unlock:
+ mutex_unlock(&dmabuf->lock);
+ return ret;
+}
+
static long dma_buf_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
ret = dma_buf_begin_cpu_access(dmabuf, direction);
return ret;
+
+ case DMA_BUF_SET_NAME:
+ return dma_buf_set_name(dmabuf, (const char __user *)arg);
+
default:
return -ENOTTY;
}
}
+static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
+{
+ struct dma_buf *dmabuf = file->private_data;
+
+ seq_printf(m, "size:\t%zu\n", dmabuf->size);
+ /* Don't count the temporary reference taken inside procfs seq_show */
+ seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1);
+ seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name);
+ mutex_lock(&dmabuf->lock);
+ if (dmabuf->name)
+ seq_printf(m, "name:\t%s\n", dmabuf->name);
+ mutex_unlock(&dmabuf->lock);
+}
+
static const struct file_operations dma_buf_fops = {
.release = dma_buf_release,
.mmap = dma_buf_mmap_internal,
#ifdef CONFIG_COMPAT
.compat_ioctl = dma_buf_ioctl,
#endif
+ .show_fdinfo = dma_buf_show_fdinfo,
};
/*
return file->f_op == &dma_buf_fops;
}
+static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
+{
+ struct file *file;
+ struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb);
+
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+
+ inode->i_size = dmabuf->size;
+ inode_set_bytes(inode, dmabuf->size);
+
+ file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf",
+ flags, &dma_buf_fops);
+ if (IS_ERR(file))
+ goto err_alloc_file;
+ file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
+ file->private_data = dmabuf;
+ file->f_path.dentry->d_fsdata = dmabuf;
+
+ return file;
+
+err_alloc_file:
+ iput(inode);
+ return file;
+}
+
/**
* DOC: dma buf device access
*
|| !exp_info->ops
|| !exp_info->ops->map_dma_buf
|| !exp_info->ops->unmap_dma_buf
- || !exp_info->ops->release
- || !exp_info->ops->mmap)) {
+ || !exp_info->ops->release)) {
return ERR_PTR(-EINVAL);
}
}
dmabuf->resv = resv;
- file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
- exp_info->flags);
+ file = dma_buf_getfile(dmabuf, exp_info->flags);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto err_dmabuf;
list_add(&attach->node, &dmabuf->attachments);
mutex_unlock(&dmabuf->lock);
+
return attach;
err_attach:
if (WARN_ON(!dmabuf || !attach))
return;
+ if (attach->sgt)
+ dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir);
+
mutex_lock(&dmabuf->lock);
list_del(&attach->node);
if (dmabuf->ops->detach)
if (WARN_ON(!attach || !attach->dmabuf))
return ERR_PTR(-EINVAL);
+ if (attach->sgt) {
+ /*
+ * Two mappings with different directions for the same
+ * attachment are not allowed.
+ */
+ if (attach->dir != direction &&
+ attach->dir != DMA_BIDIRECTIONAL)
+ return ERR_PTR(-EBUSY);
+
+ return attach->sgt;
+ }
+
sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
if (!sg_table)
sg_table = ERR_PTR(-ENOMEM);
+ if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) {
+ attach->sgt = sg_table;
+ attach->dir = direction;
+ }
+
return sg_table;
}
EXPORT_SYMBOL_GPL(dma_buf_map_attachment);
if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
return;
- attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,
- direction);
+ if (attach->sgt == sg_table)
+ return;
+
+ attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction);
}
EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
if (WARN_ON(!dmabuf || !vma))
return -EINVAL;
+ /* check if buffer supports mmap */
+ if (!dmabuf->ops->mmap)
+ return -EINVAL;
+
/* check for offset overflow */
if (pgoff + vma_pages(vma) < pgoff)
return -EOVERFLOW;
return ret;
seq_puts(s, "\nDma-buf Objects:\n");
- seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\n",
- "size", "flags", "mode", "count");
+ seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\t%-8s\n",
+ "size", "flags", "mode", "count", "ino");
list_for_each_entry(buf_obj, &db_list.head, list_node) {
ret = mutex_lock_interruptible(&buf_obj->lock);
continue;
}
- seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n",
+ seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n",
buf_obj->size,
buf_obj->file->f_flags, buf_obj->file->f_mode,
file_count(buf_obj->file),
- buf_obj->exp_name);
+ buf_obj->exp_name,
+ file_inode(buf_obj->file)->i_ino,
+ buf_obj->name ?: "");
robj = buf_obj->resv;
while (true) {
fence->ops->get_driver_name(fence),
fence->ops->get_timeline_name(fence),
dma_fence_is_signaled(fence) ? "" : "un");
+ dma_fence_put(fence);
}
rcu_read_unlock();
static int __init dma_buf_init(void)
{
+ dma_buf_mnt = kern_mount(&dma_buf_fs_type);
+ if (IS_ERR(dma_buf_mnt))
+ return PTR_ERR(dma_buf_mnt);
+
mutex_init(&db_list.lock);
INIT_LIST_HEAD(&db_list.head);
dma_buf_init_debugfs();
static void __exit dma_buf_deinit(void)
{
dma_buf_uninit_debugfs();
+ kern_unmount(dma_buf_mnt);
}
__exitcall(dma_buf_deinit);
projects / linux-2.6-block.git / blobdiff