Commit a02b9dc9 authored by Gustavo Padovan's avatar Gustavo Padovan Committed by Sumit Semwal
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dma-buf/sync_file: refactor fence storage in struct sync_file 



Create sync_file->fence to abstract the type of fence we are using for
each sync_file. If only one fence is present we use a normal struct fence
but if there is more fences to be added to the sync_file a fence_array
is created.

This change cleans up sync_file a bit. We don't need to have sync_file_cb
array anymore. Instead, as we always have  one fence, only one fence
callback is registered per sync_file.

v2: Comments from Chris Wilson and Christian König
	- Not using fence_ops anymore
	- fence_is_array() was created to differentiate fence from fence_array
	- fence_array_teardown() is now exported and used under fence_is_array()
	- struct sync_file lost num_fences member

v3: Comments from Chris Wilson and Christian König
	- struct sync_file lost status member in favor of fence_is_signaled()
	- drop use of fence_array_teardown()
	- use sizeof(*fence) to allocate only an array on fence pointers

v4: Comments from Chris Wilson
	- use sizeof(*fence) to reallocate array
	- fix typo in comments
	- protect num_fences sum against overflows
	- use array->base instead of casting the to struct fence

v5: fixes checkpatch warnings

v6: fix case where all fences are signaled.

Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
parent e1aaf311

drivers/dma-buf/sync_file.c

+115 −59
Original line number Diff line number Diff line
@@ -28,11 +28,11 @@ 


static const struct file_operations sync_file_fops;



static struct sync_file *sync_file_alloc(int size)

static struct sync_file *sync_file_alloc(void)

{

	struct sync_file *sync_file;



	sync_file = kzalloc(size, GFP_KERNEL);

	sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);

	if (!sync_file)

		return NULL;
@@ -45,6 +45,8 @@ static struct sync_file *sync_file_alloc(int size) 


	init_waitqueue_head(&sync_file->wq);



	INIT_LIST_HEAD(&sync_file->cb.node);



	return sync_file;



err:
@@ -54,13 +56,10 @@ err: 


static void fence_check_cb_func(struct fence *f, struct fence_cb *cb)

{

	struct sync_file_cb *check;

	struct sync_file *sync_file;



	check = container_of(cb, struct sync_file_cb, cb);

	sync_file = check->sync_file;

	sync_file = container_of(cb, struct sync_file, cb);



	if (atomic_dec_and_test(&sync_file->status))

	wake_up_all(&sync_file->wq);

}
@@ -76,22 +75,18 @@ struct sync_file *sync_file_create(struct fence *fence) 
{

	struct sync_file *sync_file;



	sync_file = sync_file_alloc(offsetof(struct sync_file, cbs[1]));

	sync_file = sync_file_alloc();

	if (!sync_file)

		return NULL;



	sync_file->num_fences = 1;

	atomic_set(&sync_file->status, 1);

	sync_file->fence = 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);



	sync_file->cbs[0].fence = fence;

	sync_file->cbs[0].sync_file = sync_file;

	if (fence_add_callback(fence, &sync_file->cbs[0].cb,

			       fence_check_cb_func))

		atomic_dec(&sync_file->status);

	fence_add_callback(fence, &sync_file->cb, fence_check_cb_func);



	return sync_file;

}
@@ -121,14 +116,49 @@ err: 
	return NULL;

}



static void sync_file_add_pt(struct sync_file *sync_file, int *i,

			     struct fence *fence)

static int sync_file_set_fence(struct sync_file *sync_file,

			       struct fence **fences, int num_fences)

{

	sync_file->cbs[*i].fence = fence;

	sync_file->cbs[*i].sync_file = sync_file;

	struct fence_array *array;



	if (!fence_add_callback(fence, &sync_file->cbs[*i].cb,

				fence_check_cb_func)) {

	/*

	 * 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 fence_array creation.

	 */

	if (num_fences == 1) {

		sync_file->fence = fences[0];

	} else {

		array = fence_array_create(num_fences, fences,

					   fence_context_alloc(1), 1, false);

		if (!array)

			return -ENOMEM;



		sync_file->fence = &array->base;

	}



	return 0;

}



static struct fence **get_fences(struct sync_file *sync_file, int *num_fences)

{

	if (fence_is_array(sync_file->fence)) {

		struct fence_array *array = to_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 fence **fences, int *i, struct fence *fence)

{

	fences[*i] = fence;



	if (!fence_is_signaled(fence)) {

		fence_get(fence);

		(*i)++;

	}
@@ -147,16 +177,24 @@ static void sync_file_add_pt(struct sync_file *sync_file, int *i, 
static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,

					 struct sync_file *b)

{

	int num_fences = a->num_fences + b->num_fences;

	struct sync_file *sync_file;

	int i, i_a, i_b;

	unsigned long size = offsetof(struct sync_file, cbs[num_fences]);

	struct 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(size);

	sync_file = sync_file_alloc();

	if (!sync_file)

		return NULL;



	atomic_set(&sync_file->status, num_fences);

	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
@@ -165,55 +203,73 @@ static struct sync_file *sync_file_merge(const char *name, struct sync_file *a, 
	 * 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 fence *pt_a = a->cbs[i_a].fence;

		struct fence *pt_b = b->cbs[i_b].fence;

	for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {

		struct fence *pt_a = a_fences[i_a];

		struct fence *pt_b = b_fences[i_b];



		if (pt_a->context < pt_b->context) {

			sync_file_add_pt(sync_file, &i, pt_a);

			add_fence(fences, &i, pt_a);



			i_a++;

		} else if (pt_a->context > pt_b->context) {

			sync_file_add_pt(sync_file, &i, pt_b);

			add_fence(fences, &i, pt_b);



			i_b++;

		} else {

			if (pt_a->seqno - pt_b->seqno <= INT_MAX)

				sync_file_add_pt(sync_file, &i, pt_a);

				add_fence(fences, &i, pt_a);

			else

				sync_file_add_pt(sync_file, &i, pt_b);

				add_fence(fences, &i, pt_b);



			i_a++;

			i_b++;

		}

	}



	for (; i_a < a->num_fences; i_a++)

		sync_file_add_pt(sync_file, &i, a->cbs[i_a].fence);

	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) {

		add_fence(fences, &i, a_fences[0]);

		i++;

	}



	if (num_fences > i) {

		nfences = krealloc(fences, i * sizeof(*fences),

				  GFP_KERNEL);

		if (!nfences)

			goto err;



		fences = nfences;

	}



	for (; i_b < b->num_fences; i_b++)

		sync_file_add_pt(sync_file, &i, b->cbs[i_b].fence);

	if (sync_file_set_fence(sync_file, fences, i) < 0) {

		kfree(fences);

		goto err;

	}



	if (num_fences > i)

		atomic_sub(num_fences - i, &sync_file->status);

	sync_file->num_fences = i;

	fence_add_callback(sync_file->fence, &sync_file->cb,

			   fence_check_cb_func);



	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);

	int i;



	for (i = 0; i < sync_file->num_fences; ++i) {

		fence_remove_callback(sync_file->cbs[i].fence,

				      &sync_file->cbs[i].cb);

		fence_put(sync_file->cbs[i].fence);

	}



	fence_remove_callback(sync_file->fence, &sync_file->cb);

	fence_put(sync_file->fence);

	kfree(sync_file);

}
@@ -232,9 +288,9 @@ static unsigned int sync_file_poll(struct file *file, poll_table *wait) 


	poll_wait(file, &sync_file->wq, wait);



	status = atomic_read(&sync_file->status);

	status = fence_is_signaled(sync_file->fence);



	if (!status)

	if (status)

		return POLLIN;

	if (status < 0)

		return POLLERR;
@@ -315,8 +371,9 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, 
{

	struct sync_file_info info;

	struct sync_fence_info *fence_info = NULL;

	struct fence **fences;

	__u32 size;

	int ret, i;

	int num_fences, ret, i;



	if (copy_from_user(&info, (void __user *)arg, sizeof(info)))

		return -EFAULT;
@@ -324,6 +381,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, 
	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
@@ -333,16 +392,16 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, 
	if (!info.num_fences)

		goto no_fences;



	if (info.num_fences < sync_file->num_fences)

	if (info.num_fences < num_fences)

		return -EINVAL;



	size = sync_file->num_fences * sizeof(*fence_info);

	size = num_fences * sizeof(*fence_info);

	fence_info = kzalloc(size, GFP_KERNEL);

	if (!fence_info)

		return -ENOMEM;



	for (i = 0; i < sync_file->num_fences; ++i)

		sync_fill_fence_info(sync_file->cbs[i].fence, &fence_info[i]);

	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)) {
@@ -352,11 +411,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, 


no_fences:

	strlcpy(info.name, sync_file->name, sizeof(info.name));

	info.status = atomic_read(&sync_file->status);

	if (info.status >= 0)

		info.status = !info.status;



	info.num_fences = sync_file->num_fences;

	info.status = fence_is_signaled(sync_file->fence);

	info.num_fences = num_fences;



	if (copy_to_user((void __user *)arg, &info, sizeof(info)))

		ret = -EFAULT;

drivers/staging/android/sync_debug.c

+9 −3
Original line number Diff line number Diff line
@@ -135,10 +135,16 @@ static void sync_print_sync_file(struct seq_file *s, 
	int i;



	seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,

		   sync_status_str(atomic_read(&sync_file->status)));

		   sync_status_str(!fence_is_signaled(sync_file->fence)));



	for (i = 0; i < sync_file->num_fences; ++i)

		sync_print_fence(s, sync_file->cbs[i].fence, true);

	if (fence_is_array(sync_file->fence)) {

		struct fence_array *array = to_fence_array(sync_file->fence);



		for (i = 0; i < array->num_fences; ++i)

			sync_print_fence(s, array->fences[i], true);

	} else {

		sync_print_fence(s, sync_file->fence, true);

	}

}



static int sync_debugfs_show(struct seq_file *s, void *unused)

include/linux/sync_file.h

+5 −12
Original line number Diff line number Diff line
@@ -19,12 +19,7 @@ 
#include <linux/list.h>

#include <linux/spinlock.h>

#include <linux/fence.h>



struct sync_file_cb {

	struct fence_cb cb;

	struct fence *fence;

	struct sync_file *sync_file;

};

#include <linux/fence-array.h>



/**

 * struct sync_file - sync file to export to the userspace
@@ -32,10 +27,9 @@ struct sync_file_cb { 
 * @kref:		reference count on fence.

 * @name:		name of sync_file.  Useful for debugging

 * @sync_file_list:	membership in global file list

 * @num_fences:		number of sync_pts in the fence

 * @wq:			wait queue for fence signaling

 * @status:		0: signaled, >0:active, <0: error

 * @cbs:		sync_pts callback information

 * @fence:		fence with the fences in the sync_file

 * @cb:			fence callback information

 */

struct sync_file {

	struct file		*file;
@@ -44,12 +38,11 @@ struct sync_file { 
#ifdef CONFIG_DEBUG_FS

	struct list_head	sync_file_list;

#endif

	int num_fences;



	wait_queue_head_t	wq;

	atomic_t		status;



	struct sync_file_cb	cbs[];

	struct fence		*fence;

	struct fence_cb cb;

};



struct sync_file *sync_file_create(struct fence *fence);

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