[mirror_ubuntu-zesty-kernel.git] / drivers / dma-buf / sync_file.c

/*
 * drivers/dma-buf/sync_file.c
 *
 * Copyright (C) 2012 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 *
 */

#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;

	kref_init(&sync_file->kref);

	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. Once this is called, the sync_file
 * takes ownership of @fence. 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);

	snprintf(sync_file->name, sizeof(sync_file->name), "%s-%s%llu-%d",
		 fence->ops->get_driver_name(fence),
		 fence->ops->get_timeline_name(fence), fence->context,
		 fence->seqno);

	return sync_file;
}
EXPORT_SYMBOL(sync_file_create);

/**
 * sync_file_fdget() - get a sync_file from an fd
 * @fd:		fd referencing a fence
 *
 * Ensures @fd references a valid sync_file, increments the refcount of the
 * backing file. Returns the sync_file or NULL in case of error.
 */
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);

static int sync_file_set_fence(struct sync_file *sync_file,
			       struct dma_fence **fences, int num_fences)
{
	struct dma_fence_array *array;

	/*
	 * The reference for the fences in the new sync_file and held
	 * in add_fence() during the merge procedure, so for num_fences == 1
	 * we already own a new reference to the fence. For num_fence > 1
	 * we own the reference of the dma_fence_array creation.
	 */
	if (num_fences == 1) {
		sync_file->fence = fences[0];
		kfree(fences);
	} else {
		array = dma_fence_array_create(num_fences, fences,
					       dma_fence_context_alloc(1),
					       1, false);
		if (!array)
			return -ENOMEM;

		sync_file->fence = &array->base;
	}

	return 0;
}

static struct dma_fence **get_fences(struct sync_file *sync_file,
				     int *num_fences)
{
	if (dma_fence_is_array(sync_file->fence)) {
		struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);

		*num_fences = array->num_fences;
		return array->fences;
	}

	*num_fences = 1;
	return &sync_file->fence;
}

static void add_fence(struct dma_fence **fences,
		      int *i, struct dma_fence *fence)
{
	fences[*i] = fence;

	if (!dma_fence_is_signaled(fence)) {
		dma_fence_get(fence);
		(*i)++;
	}
}

/**
 * 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 **fences, **nfences, **a_fences, **b_fences;
	int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;

	sync_file = sync_file_alloc();
	if (!sync_file)
		return NULL;

	a_fences = get_fences(a, &a_num_fences);
	b_fences = get_fences(b, &b_num_fences);
	if (a_num_fences > INT_MAX - b_num_fences)
		return NULL;

	num_fences = a_num_fences + b_num_fences;

	fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
	if (!fences)
		goto err;

	/*
	 * Assume sync_file a and b are both ordered and have no
	 * duplicates with the same context.
	 *
	 * If a sync_file can only be created with sync_file_merge
	 * and sync_file_create, this is a reasonable assumption.
	 */
	for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
		struct dma_fence *pt_a = a_fences[i_a];
		struct dma_fence *pt_b = b_fences[i_b];

		if (pt_a->context < pt_b->context) {
			add_fence(fences, &i, pt_a);

			i_a++;
		} else if (pt_a->context > pt_b->context) {
			add_fence(fences, &i, pt_b);

			i_b++;
		} else {
			if (pt_a->seqno - pt_b->seqno <= INT_MAX)
				add_fence(fences, &i, pt_a);
			else
				add_fence(fences, &i, pt_b);

			i_a++;
			i_b++;
		}
	}

	for (; i_a < a_num_fences; i_a++)
		add_fence(fences, &i, a_fences[i_a]);

	for (; i_b < b_num_fences; i_b++)
		add_fence(fences, &i, b_fences[i_b]);

	if (i == 0)
		fences[i++] = dma_fence_get(a_fences[0]);

	if (num_fences > i) {
		nfences = krealloc(fences, i * sizeof(*fences),
				  GFP_KERNEL);
		if (!nfences)
			goto err;

		fences = nfences;
	}

	if (sync_file_set_fence(sync_file, fences, i) < 0) {
		kfree(fences);
		goto err;
	}

	strlcpy(sync_file->name, name, sizeof(sync_file->name));
	return sync_file;

err:
	fput(sync_file->file);
	return NULL;

}

static void sync_file_free(struct kref *kref)
{
	struct sync_file *sync_file = container_of(kref, struct sync_file,
						     kref);

	if (test_bit(POLL_ENABLED, &sync_file->fence->flags))
		dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
	dma_fence_put(sync_file->fence);
	kfree(sync_file);
}

static int sync_file_release(struct inode *inode, struct file *file)
{
	struct sync_file *sync_file = file->private_data;

	kref_put(&sync_file->kref, sync_file_free);
	return 0;
}

static unsigned int 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 (!test_and_set_bit(POLL_ENABLED, &sync_file->fence->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) ? POLLIN : 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 void sync_fill_fence_info(struct dma_fence *fence,
				 struct sync_fence_info *info)
{
	strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
		sizeof(info->obj_name));
	strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
		sizeof(info->driver_name));
	if (dma_fence_is_signaled(fence))
		info->status = fence->status >= 0 ? 1 : fence->status;
	else
		info->status = 0;
	info->timestamp_ns = ktime_to_ns(fence->timestamp);
}

static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
				       unsigned long arg)
{
	struct sync_file_info info;
	struct sync_fence_info *fence_info = NULL;
	struct dma_fence **fences;
	__u32 size;
	int num_fences, ret, i;

	if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
		return -EFAULT;

	if (info.flags || info.pad)
		return -EINVAL;

	fences = get_fences(sync_file, &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)
		goto no_fences;

	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;

	for (i = 0; i < num_fences; i++)
		sync_fill_fence_info(fences[i], &fence_info[i]);

	if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
			 size)) {
		ret = -EFAULT;
		goto out;
	}

no_fences:
	strlcpy(info.name, sync_file->name, sizeof(info.name));
	info.status = dma_fence_is_signaled(sync_file->fence);
	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 = sync_file_ioctl,
};
Commit	Line	Data
d4cab38e GP	1	/*
	2	* drivers/dma-buf/sync_file.c
	3	*
	4	* Copyright (C) 2012 Google, Inc.
	5	*
	6	* This software is licensed under the terms of the GNU General Public
	7	* License version 2, as published by the Free Software Foundation, and
	8	* may be copied, distributed, and modified under those terms.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	*/
	16
	17	#include <linux/export.h>
	18	#include <linux/file.h>
	19	#include <linux/fs.h>
	20	#include <linux/kernel.h>
	21	#include <linux/poll.h>
	22	#include <linux/sched.h>
	23	#include <linux/slab.h>
	24	#include <linux/uaccess.h>
	25	#include <linux/anon_inodes.h>
460bfc41 GP	26	#include <linux/sync_file.h>
460bfc41 GP	27	#include <uapi/linux/sync_file.h>
d4cab38e GP	28
	29	static const struct file_operations sync_file_fops;
	30
a02b9dc9	31	static struct sync_file *sync_file_alloc(void)
d4cab38e GP	32	{
	33	struct sync_file *sync_file;
	34
a02b9dc9	35	sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
d4cab38e GP	36	if (!sync_file)
	37	return NULL;
	38
	39	sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops,
	40	sync_file, 0);
	41	if (IS_ERR(sync_file->file))
	42	goto err;
	43
	44	kref_init(&sync_file->kref);
	45
	46	init_waitqueue_head(&sync_file->wq);
	47
a02b9dc9 GP	48	INIT_LIST_HEAD(&sync_file->cb.node);
a02b9dc9 GP	49
d4cab38e GP	50	return sync_file;
	51
	52	err:
	53	kfree(sync_file);
	54	return NULL;
	55	}
	56
f54d1867	57	static void fence_check_cb_func(struct dma_fence f, struct dma_fence_cb cb)
d4cab38e	58	{
d4cab38e GP	59	struct sync_file *sync_file;
d4cab38e GP	60
a02b9dc9	61	sync_file = container_of(cb, struct sync_file, cb);
d4cab38e	62
a02b9dc9	63	wake_up_all(&sync_file->wq);
d4cab38e GP	64	}
	65
	66	/**
c240a714	67	* sync_file_create() - creates a sync file
d4cab38e GP	68	* @fence: fence to add to the sync_fence
	69	*
	70	* Creates a sync_file containg @fence. Once this is called, the sync_file
c240a714 GP	71	* takes ownership of @fence. The sync_file can be released with
c240a714 GP	72	* fput(sync_file->file). Returns the sync_file or NULL in case of error.
d4cab38e	73	*/
f54d1867	74	struct sync_file sync_file_create(struct dma_fence fence)
d4cab38e GP	75	{
	76	struct sync_file *sync_file;
	77
a02b9dc9	78	sync_file = sync_file_alloc();
d4cab38e GP	79	if (!sync_file)
	80	return NULL;
	81
f54d1867	82	sync_file->fence = dma_fence_get(fence);
a02b9dc9	83
041916a7	84	snprintf(sync_file->name, sizeof(sync_file->name), "%s-%s%llu-%d",
d4cab38e GP	85	fence->ops->get_driver_name(fence),
	86	fence->ops->get_timeline_name(fence), fence->context,
	87	fence->seqno);
	88
d4cab38e GP	89	return sync_file;
	90	}
	91	EXPORT_SYMBOL(sync_file_create);
	92
	93	/**
	94	* sync_file_fdget() - get a sync_file from an fd
	95	* @fd: fd referencing a fence
	96	*
	97	* Ensures @fd references a valid sync_file, increments the refcount of the
	98	* backing file. Returns the sync_file or NULL in case of error.
	99	*/
	100	static struct sync_file *sync_file_fdget(int fd)
	101	{
	102	struct file *file = fget(fd);
	103
	104	if (!file)
	105	return NULL;
	106
	107	if (file->f_op != &sync_file_fops)
	108	goto err;
	109
	110	return file->private_data;
	111
	112	err:
	113	fput(file);
	114	return NULL;
	115	}
	116
972526a4 GP	117	/**
	118	* sync_file_get_fence - get the fence related to the sync_file fd
	119	* @fd: sync_file fd to get the fence from
	120	*
	121	* Ensures @fd references a valid sync_file and returns a fence that
	122	* represents all fence in the sync_file. On error NULL is returned.
	123	*/
f54d1867	124	struct dma_fence *sync_file_get_fence(int fd)
972526a4 GP	125	{
972526a4 GP	126	struct sync_file *sync_file;
f54d1867	127	struct dma_fence *fence;
972526a4 GP	128
	129	sync_file = sync_file_fdget(fd);
	130	if (!sync_file)
	131	return NULL;
	132
f54d1867	133	fence = dma_fence_get(sync_file->fence);
972526a4 GP	134	fput(sync_file->file);
	135
	136	return fence;
	137	}
	138	EXPORT_SYMBOL(sync_file_get_fence);
	139
a02b9dc9	140	static int sync_file_set_fence(struct sync_file *sync_file,
f54d1867	141	struct dma_fence **fences, int num_fences)
d4cab38e	142	{
f54d1867	143	struct dma_fence_array *array;
a02b9dc9 GP	144
	145	/*
	146	* The reference for the fences in the new sync_file and held
	147	* in add_fence() during the merge procedure, so for num_fences == 1
	148	* we already own a new reference to the fence. For num_fence > 1
f54d1867	149	* we own the reference of the dma_fence_array creation.
a02b9dc9 GP	150	*/
	151	if (num_fences == 1) {
	152	sync_file->fence = fences[0];
c654dd07	153	kfree(fences);
a02b9dc9	154	} else {
f54d1867 CW	155	array = dma_fence_array_create(num_fences, fences,
	156	dma_fence_context_alloc(1),
	157	1, false);
a02b9dc9 GP	158	if (!array)
	159	return -ENOMEM;
	160
	161	sync_file->fence = &array->base;
	162	}
d4cab38e	163
a02b9dc9 GP	164	return 0;
	165	}
	166
f54d1867 CW	167	static struct dma_fence *get_fences(struct sync_file sync_file,
f54d1867 CW	168	int *num_fences)
a02b9dc9	169	{
f54d1867 CW	170	if (dma_fence_is_array(sync_file->fence)) {
f54d1867 CW	171	struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);
a02b9dc9 GP	172
	173	*num_fences = array->num_fences;
	174	return array->fences;
	175	}
	176
	177	*num_fences = 1;
	178	return &sync_file->fence;
	179	}
	180
f54d1867 CW	181	static void add_fence(struct dma_fence **fences,
f54d1867 CW	182	int i, struct dma_fence fence)
a02b9dc9 GP	183	{
	184	fences[*i] = fence;
	185
f54d1867 CW	186	if (!dma_fence_is_signaled(fence)) {
f54d1867 CW	187	dma_fence_get(fence);
d4cab38e GP	188	(*i)++;
	189	}
	190	}
	191
	192	/**
	193	* sync_file_merge() - merge two sync_files
	194	* @name: name of new fence
	195	* @a: sync_file a
	196	* @b: sync_file b
	197	*
	198	* Creates a new sync_file which contains copies of all the fences in both
	199	* @a and @b. @a and @b remain valid, independent sync_file. Returns the
	200	* new merged sync_file or NULL in case of error.
	201	*/
	202	static struct sync_file sync_file_merge(const char name, struct sync_file *a,
	203	struct sync_file *b)
	204	{
d4cab38e	205	struct sync_file *sync_file;
f54d1867	206	struct dma_fence fences, nfences, a_fences, b_fences;
a02b9dc9	207	int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;
d4cab38e	208
a02b9dc9	209	sync_file = sync_file_alloc();
d4cab38e GP	210	if (!sync_file)
	211	return NULL;
	212
a02b9dc9 GP	213	a_fences = get_fences(a, &a_num_fences);
	214	b_fences = get_fences(b, &b_num_fences);
	215	if (a_num_fences > INT_MAX - b_num_fences)
	216	return NULL;
	217
	218	num_fences = a_num_fences + b_num_fences;
	219
	220	fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
	221	if (!fences)
	222	goto err;
d4cab38e GP	223
	224	/*
	225	* Assume sync_file a and b are both ordered and have no
	226	* duplicates with the same context.
	227	*
	228	* If a sync_file can only be created with sync_file_merge
	229	* and sync_file_create, this is a reasonable assumption.
	230	*/
a02b9dc9	231	for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
f54d1867 CW	232	struct dma_fence *pt_a = a_fences[i_a];
f54d1867 CW	233	struct dma_fence *pt_b = b_fences[i_b];
d4cab38e GP	234
d4cab38e GP	235	if (pt_a->context < pt_b->context) {
a02b9dc9	236	add_fence(fences, &i, pt_a);
d4cab38e GP	237
	238	i_a++;
	239	} else if (pt_a->context > pt_b->context) {
a02b9dc9	240	add_fence(fences, &i, pt_b);
d4cab38e GP	241
	242	i_b++;
	243	} else {
	244	if (pt_a->seqno - pt_b->seqno <= INT_MAX)
a02b9dc9	245	add_fence(fences, &i, pt_a);
d4cab38e	246	else
a02b9dc9	247	add_fence(fences, &i, pt_b);
d4cab38e GP	248
	249	i_a++;
	250	i_b++;
	251	}
	252	}
	253
a02b9dc9 GP	254	for (; i_a < a_num_fences; i_a++)
	255	add_fence(fences, &i, a_fences[i_a]);
	256
	257	for (; i_b < b_num_fences; i_b++)
	258	add_fence(fences, &i, b_fences[i_b]);
	259
7cec540a	260	if (i == 0)
f54d1867	261	fences[i++] = dma_fence_get(a_fences[0]);
d4cab38e	262
a02b9dc9 GP	263	if (num_fences > i) {
	264	nfences = krealloc(fences, i * sizeof(*fences),
	265	GFP_KERNEL);
	266	if (!nfences)
	267	goto err;
	268
	269	fences = nfences;
	270	}
	271
	272	if (sync_file_set_fence(sync_file, fences, i) < 0) {
	273	kfree(fences);
	274	goto err;
	275	}
d4cab38e	276
d4cab38e GP	277	strlcpy(sync_file->name, name, sizeof(sync_file->name));
d4cab38e GP	278	return sync_file;
a02b9dc9 GP	279
	280	err:
	281	fput(sync_file->file);
	282	return NULL;
	283
d4cab38e GP	284	}
	285
	286	static void sync_file_free(struct kref *kref)
	287	{
	288	struct sync_file *sync_file = container_of(kref, struct sync_file,
	289	kref);
d4cab38e	290
e2416553	291	if (test_bit(POLL_ENABLED, &sync_file->fence->flags))
f54d1867 CW	292	dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
f54d1867 CW	293	dma_fence_put(sync_file->fence);
d4cab38e GP	294	kfree(sync_file);
	295	}
	296
	297	static int sync_file_release(struct inode inode, struct file file)
	298	{
	299	struct sync_file *sync_file = file->private_data;
	300
	301	kref_put(&sync_file->kref, sync_file_free);
	302	return 0;
	303	}
	304
	305	static unsigned int sync_file_poll(struct file file, poll_table wait)
	306	{
	307	struct sync_file *sync_file = file->private_data;
d4cab38e GP	308
	309	poll_wait(file, &sync_file->wq, wait);
	310
069cad6d	311	if (!test_and_set_bit(POLL_ENABLED, &sync_file->fence->flags)) {
f54d1867 CW	312	if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,
f54d1867 CW	313	fence_check_cb_func) < 0)
e2416553 GP	314	wake_up_all(&sync_file->wq);
e2416553 GP	315	}
d4cab38e	316
f54d1867	317	return dma_fence_is_signaled(sync_file->fence) ? POLLIN : 0;
d4cab38e GP	318	}
	319
	320	static long sync_file_ioctl_merge(struct sync_file *sync_file,
92e06213	321	unsigned long arg)
d4cab38e GP	322	{
	323	int fd = get_unused_fd_flags(O_CLOEXEC);
	324	int err;
	325	struct sync_file fence2, fence3;
	326	struct sync_merge_data data;
	327
	328	if (fd < 0)
	329	return fd;
	330
	331	if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
	332	err = -EFAULT;
	333	goto err_put_fd;
	334	}
	335
	336	if (data.flags \|\| data.pad) {
	337	err = -EINVAL;
	338	goto err_put_fd;
	339	}
	340
	341	fence2 = sync_file_fdget(data.fd2);
	342	if (!fence2) {
	343	err = -ENOENT;
	344	goto err_put_fd;
	345	}
	346
	347	data.name[sizeof(data.name) - 1] = '\0';
	348	fence3 = sync_file_merge(data.name, sync_file, fence2);
	349	if (!fence3) {
	350	err = -ENOMEM;
	351	goto err_put_fence2;
	352	}
	353
	354	data.fence = fd;
	355	if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
	356	err = -EFAULT;
	357	goto err_put_fence3;
	358	}
	359
	360	fd_install(fd, fence3->file);
	361	fput(fence2->file);
	362	return 0;
	363
	364	err_put_fence3:
	365	fput(fence3->file);
	366
	367	err_put_fence2:
	368	fput(fence2->file);
	369
	370	err_put_fd:
	371	put_unused_fd(fd);
	372	return err;
	373	}
	374
f54d1867	375	static void sync_fill_fence_info(struct dma_fence *fence,
92e06213	376	struct sync_fence_info *info)
d4cab38e GP	377	{
	378	strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
	379	sizeof(info->obj_name));
	380	strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
	381	sizeof(info->driver_name));
f54d1867	382	if (dma_fence_is_signaled(fence))
d4cab38e GP	383	info->status = fence->status >= 0 ? 1 : fence->status;
	384	else
	385	info->status = 0;
	386	info->timestamp_ns = ktime_to_ns(fence->timestamp);
	387	}
	388
	389	static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
92e06213	390	unsigned long arg)
d4cab38e GP	391	{
	392	struct sync_file_info info;
	393	struct sync_fence_info *fence_info = NULL;
f54d1867	394	struct dma_fence **fences;
d4cab38e	395	__u32 size;
a02b9dc9	396	int num_fences, ret, i;
d4cab38e GP	397
	398	if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
	399	return -EFAULT;
	400
	401	if (info.flags \|\| info.pad)
	402	return -EINVAL;
	403
a02b9dc9 GP	404	fences = get_fences(sync_file, &num_fences);
a02b9dc9 GP	405
d4cab38e GP	406	/*
	407	* Passing num_fences = 0 means that userspace doesn't want to
	408	* retrieve any sync_fence_info. If num_fences = 0 we skip filling
	409	* sync_fence_info and return the actual number of fences on
	410	* info->num_fences.
	411	*/
	412	if (!info.num_fences)
	413	goto no_fences;
	414
a02b9dc9	415	if (info.num_fences < num_fences)
d4cab38e GP	416	return -EINVAL;
d4cab38e GP	417
a02b9dc9	418	size = num_fences * sizeof(*fence_info);
d4cab38e GP	419	fence_info = kzalloc(size, GFP_KERNEL);
	420	if (!fence_info)
	421	return -ENOMEM;
	422
a02b9dc9 GP	423	for (i = 0; i < num_fences; i++)
a02b9dc9 GP	424	sync_fill_fence_info(fences[i], &fence_info[i]);
d4cab38e GP	425
	426	if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
	427	size)) {
	428	ret = -EFAULT;
	429	goto out;
	430	}
	431
	432	no_fences:
	433	strlcpy(info.name, sync_file->name, sizeof(info.name));
f54d1867	434	info.status = dma_fence_is_signaled(sync_file->fence);
a02b9dc9	435	info.num_fences = num_fences;
d4cab38e GP	436
	437	if (copy_to_user((void __user *)arg, &info, sizeof(info)))
	438	ret = -EFAULT;
	439	else
	440	ret = 0;
	441
	442	out:
	443	kfree(fence_info);
	444
	445	return ret;
	446	}
	447
	448	static long sync_file_ioctl(struct file *file, unsigned int cmd,
92e06213	449	unsigned long arg)
d4cab38e GP	450	{
	451	struct sync_file *sync_file = file->private_data;
	452
	453	switch (cmd) {
	454	case SYNC_IOC_MERGE:
	455	return sync_file_ioctl_merge(sync_file, arg);
	456
	457	case SYNC_IOC_FILE_INFO:
	458	return sync_file_ioctl_fence_info(sync_file, arg);
	459
	460	default:
	461	return -ENOTTY;
	462	}
	463	}
	464
	465	static const struct file_operations sync_file_fops = {
	466	.release = sync_file_release,
	467	.poll = sync_file_poll,
	468	.unlocked_ioctl = sync_file_ioctl,
	469	.compat_ioctl = sync_file_ioctl,
	470	};
	471