blob: af57799c86ceec5bb4b8f4354aa3bbc822211771 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/dma-buf/sync_file.c
*
* Copyright (C) 2012 Google, Inc.
*/
#include <linux/dma-fence-unwrap.h>
#include <linux/export.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/anon_inodes.h>
#include <linux/sync_file.h>
#include <uapi/linux/sync_file.h>
static const struct file_operations sync_file_fops;
static struct sync_file *sync_file_alloc(void)
{
struct sync_file *sync_file;
sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
if (!sync_file)
return NULL;
sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops,
sync_file, 0);
if (IS_ERR(sync_file->file))
goto err;
init_waitqueue_head(&sync_file->wq);
INIT_LIST_HEAD(&sync_file->cb.node);
return sync_file;
err:
kfree(sync_file);
return NULL;
}
static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb)
{
struct sync_file *sync_file;
sync_file = container_of(cb, struct sync_file, cb);
wake_up_all(&sync_file->wq);
}
/**
* sync_file_create() - creates a sync file
* @fence: fence to add to the sync_fence
*
* Creates a sync_file containg @fence. This function acquires and additional
* reference of @fence for the newly-created &sync_file, if it succeeds. The
* sync_file can be released with fput(sync_file->file). Returns the
* sync_file or NULL in case of error.
*/
struct sync_file *sync_file_create(struct dma_fence *fence)
{
struct sync_file *sync_file;
sync_file = sync_file_alloc();
if (!sync_file)
return NULL;
sync_file->fence = dma_fence_get(fence);
return sync_file;
}
EXPORT_SYMBOL(sync_file_create);
static struct sync_file *sync_file_fdget(int fd)
{
struct file *file = fget(fd);
if (!file)
return NULL;
if (file->f_op != &sync_file_fops)
goto err;
return file->private_data;
err:
fput(file);
return NULL;
}
/**
* sync_file_get_fence - get the fence related to the sync_file fd
* @fd: sync_file fd to get the fence from
*
* Ensures @fd references a valid sync_file and returns a fence that
* represents all fence in the sync_file. On error NULL is returned.
*/
struct dma_fence *sync_file_get_fence(int fd)
{
struct sync_file *sync_file;
struct dma_fence *fence;
sync_file = sync_file_fdget(fd);
if (!sync_file)
return NULL;
fence = dma_fence_get(sync_file->fence);
fput(sync_file->file);
return fence;
}
EXPORT_SYMBOL(sync_file_get_fence);
/**
* sync_file_get_name - get the name of the sync_file
* @sync_file: sync_file to get the fence from
* @buf: destination buffer to copy sync_file name into
* @len: available size of destination buffer.
*
* Each sync_file may have a name assigned either by the user (when merging
* sync_files together) or created from the fence it contains. In the latter
* case construction of the name is deferred until use, and so requires
* sync_file_get_name().
*
* Returns: a string representing the name.
*/
char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len)
{
if (sync_file->user_name[0]) {
strscpy(buf, sync_file->user_name, len);
} else {
struct dma_fence *fence = sync_file->fence;
snprintf(buf, len, "%s-%s%llu-%lld",
fence->ops->get_driver_name(fence),
fence->ops->get_timeline_name(fence),
fence->context,
fence->seqno);
}
return buf;
}
/**
* sync_file_merge() - merge two sync_files
* @name: name of new fence
* @a: sync_file a
* @b: sync_file b
*
* Creates a new sync_file which contains copies of all the fences in both
* @a and @b. @a and @b remain valid, independent sync_file. Returns the
* new merged sync_file or NULL in case of error.
*/
static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
struct sync_file *b)
{
struct sync_file *sync_file;
struct dma_fence *fence;
sync_file = sync_file_alloc();
if (!sync_file)
return NULL;
fence = dma_fence_unwrap_merge(a->fence, b->fence);
if (!fence) {
fput(sync_file->file);
return NULL;
}
sync_file->fence = fence;
strscpy(sync_file->user_name, name, sizeof(sync_file->user_name));
return sync_file;
}
static int sync_file_release(struct inode *inode, struct file *file)
{
struct sync_file *sync_file = file->private_data;
if (test_bit(POLL_ENABLED, &sync_file->flags))
dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
dma_fence_put(sync_file->fence);
kfree(sync_file);
return 0;
}
static __poll_t sync_file_poll(struct file *file, poll_table *wait)
{
struct sync_file *sync_file = file->private_data;
poll_wait(file, &sync_file->wq, wait);
if (list_empty(&sync_file->cb.node) &&
!test_and_set_bit(POLL_ENABLED, &sync_file->flags)) {
if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,
fence_check_cb_func) < 0)
wake_up_all(&sync_file->wq);
}
return dma_fence_is_signaled(sync_file->fence) ? EPOLLIN : 0;
}
static long sync_file_ioctl_merge(struct sync_file *sync_file,
unsigned long arg)
{
int fd = get_unused_fd_flags(O_CLOEXEC);
int err;
struct sync_file *fence2, *fence3;
struct sync_merge_data data;
if (fd < 0)
return fd;
if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
err = -EFAULT;
goto err_put_fd;
}
if (data.flags || data.pad) {
err = -EINVAL;
goto err_put_fd;
}
fence2 = sync_file_fdget(data.fd2);
if (!fence2) {
err = -ENOENT;
goto err_put_fd;
}
data.name[sizeof(data.name) - 1] = '\0';
fence3 = sync_file_merge(data.name, sync_file, fence2);
if (!fence3) {
err = -ENOMEM;
goto err_put_fence2;
}
data.fence = fd;
if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
err = -EFAULT;
goto err_put_fence3;
}
fd_install(fd, fence3->file);
fput(fence2->file);
return 0;
err_put_fence3:
fput(fence3->file);
err_put_fence2:
fput(fence2->file);
err_put_fd:
put_unused_fd(fd);
return err;
}
static int sync_fill_fence_info(struct dma_fence *fence,
struct sync_fence_info *info)
{
strscpy(info->obj_name, fence->ops->get_timeline_name(fence),
sizeof(info->obj_name));
strscpy(info->driver_name, fence->ops->get_driver_name(fence),
sizeof(info->driver_name));
info->status = dma_fence_get_status(fence);
while (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) &&
!test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags))
cpu_relax();
info->timestamp_ns =
test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags) ?
ktime_to_ns(fence->timestamp) :
ktime_set(0, 0);
return info->status;
}
static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
unsigned long arg)
{
struct sync_fence_info *fence_info = NULL;
struct dma_fence_unwrap iter;
struct sync_file_info info;
unsigned int num_fences;
struct dma_fence *fence;
int ret;
__u32 size;
if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
return -EFAULT;
if (info.flags || info.pad)
return -EINVAL;
num_fences = 0;
dma_fence_unwrap_for_each(fence, &iter, sync_file->fence)
++num_fences;
/*
* Passing num_fences = 0 means that userspace doesn't want to
* retrieve any sync_fence_info. If num_fences = 0 we skip filling
* sync_fence_info and return the actual number of fences on
* info->num_fences.
*/
if (!info.num_fences) {
info.status = dma_fence_get_status(sync_file->fence);
goto no_fences;
} else {
info.status = 1;
}
if (info.num_fences < num_fences)
return -EINVAL;
size = num_fences * sizeof(*fence_info);
fence_info = kzalloc(size, GFP_KERNEL);
if (!fence_info)
return -ENOMEM;
num_fences = 0;
dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) {
int status;
status = sync_fill_fence_info(fence, &fence_info[num_fences++]);
info.status = info.status <= 0 ? info.status : status;
}
if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
size)) {
ret = -EFAULT;
goto out;
}
no_fences:
sync_file_get_name(sync_file, info.name, sizeof(info.name));
info.num_fences = num_fences;
if (copy_to_user((void __user *)arg, &info, sizeof(info)))
ret = -EFAULT;
else
ret = 0;
out:
kfree(fence_info);
return ret;
}
static long sync_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct sync_file *sync_file = file->private_data;
switch (cmd) {
case SYNC_IOC_MERGE:
return sync_file_ioctl_merge(sync_file, arg);
case SYNC_IOC_FILE_INFO:
return sync_file_ioctl_fence_info(sync_file, arg);
default:
return -ENOTTY;
}
}
static const struct file_operations sync_file_fops = {
.release = sync_file_release,
.poll = sync_file_poll,
.unlocked_ioctl = sync_file_ioctl,
.compat_ioctl = compat_ptr_ioctl,
};