Commit 70e67aae authored by Rob Clark's avatar Rob Clark Committed by Dmitry Baryshkov
Browse files

dma-buf/sw_sync: Add fence deadline support 



This consists of simply storing the most recent deadline, and adding an
ioctl to retrieve the deadline.  This can be used in conjunction with
the SET_DEADLINE ioctl on a fence fd for testing.  Ie. create various
sw_sync fences, merge them into a fence-array, set deadline on the
fence-array and confirm that it is propagated properly to each fence.

v2: Switch UABI to express deadline as u64
v3: More verbose UAPI docs, show how to convert from timespec
v4: Better comments, track the soonest deadline, as a normal fence
    implementation would, return an error if no deadline set.

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Acked-by: default avatarPekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230823215458.203366-4-robdclark@gmail.com
parent 63ee4454

drivers/dma-buf/sw_sync.c

+82 −0
Original line number Diff line number Diff line
@@ -52,12 +52,33 @@ struct sw_sync_create_fence_data { 
	__s32	fence; /* fd of new fence */

};



/**

 * struct sw_sync_get_deadline - get the deadline hint of a sw_sync fence

 * @deadline_ns: absolute time of the deadline

 * @pad:	must be zero

 * @fence_fd:	the sw_sync fence fd (in)

 *

 * Return the earliest deadline set on the fence.  The timebase for the

 * deadline is CLOCK_MONOTONIC (same as vblank).  If there is no deadline

 * set on the fence, this ioctl will return -ENOENT.

 */

struct sw_sync_get_deadline {

	__u64	deadline_ns;

	__u32	pad;

	__s32	fence_fd;

};



#define SW_SYNC_IOC_MAGIC	'W'



#define SW_SYNC_IOC_CREATE_FENCE	_IOWR(SW_SYNC_IOC_MAGIC, 0,\

		struct sw_sync_create_fence_data)



#define SW_SYNC_IOC_INC			_IOW(SW_SYNC_IOC_MAGIC, 1, __u32)

#define SW_SYNC_GET_DEADLINE		_IOWR(SW_SYNC_IOC_MAGIC, 2, \

		struct sw_sync_get_deadline)





#define SW_SYNC_HAS_DEADLINE_BIT	DMA_FENCE_FLAG_USER_BITS



static const struct dma_fence_ops timeline_fence_ops;
@@ -171,6 +192,22 @@ static void timeline_fence_timeline_value_str(struct dma_fence *fence, 
	snprintf(str, size, "%d", parent->value);

}



static void timeline_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)

{

	struct sync_pt *pt = dma_fence_to_sync_pt(fence);

	unsigned long flags;



	spin_lock_irqsave(fence->lock, flags);

	if (test_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags)) {

		if (ktime_before(deadline, pt->deadline))

			pt->deadline = deadline;

	} else {

		pt->deadline = deadline;

		__set_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags);

	}

	spin_unlock_irqrestore(fence->lock, flags);

}



static const struct dma_fence_ops timeline_fence_ops = {

	.get_driver_name = timeline_fence_get_driver_name,

	.get_timeline_name = timeline_fence_get_timeline_name,
@@ -179,6 +216,7 @@ static const struct dma_fence_ops timeline_fence_ops = { 
	.release = timeline_fence_release,

	.fence_value_str = timeline_fence_value_str,

	.timeline_value_str = timeline_fence_timeline_value_str,

	.set_deadline = timeline_fence_set_deadline,

};



/**
@@ -387,6 +425,47 @@ static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg) 
	return 0;

}



static int sw_sync_ioctl_get_deadline(struct sync_timeline *obj, unsigned long arg)

{

	struct sw_sync_get_deadline data;

	struct dma_fence *fence;

	unsigned long flags;

	struct sync_pt *pt;

	int ret = 0;



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

		return -EFAULT;



	if (data.deadline_ns || data.pad)

		return -EINVAL;



	fence = sync_file_get_fence(data.fence_fd);

	if (!fence)

		return -EINVAL;



	pt = dma_fence_to_sync_pt(fence);

	if (!pt)

		return -EINVAL;



	spin_lock_irqsave(fence->lock, flags);

	if (test_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags)) {

		data.deadline_ns = ktime_to_ns(pt->deadline);

	} else {

		ret = -ENOENT;

	}

	spin_unlock_irqrestore(fence->lock, flags);



	dma_fence_put(fence);



	if (ret)

		return ret;



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

		return -EFAULT;



	return 0;

}



static long sw_sync_ioctl(struct file *file, unsigned int cmd,

			  unsigned long arg)

{
@@ -399,6 +478,9 @@ static long sw_sync_ioctl(struct file *file, unsigned int cmd, 
	case SW_SYNC_IOC_INC:

		return sw_sync_ioctl_inc(obj, arg);



	case SW_SYNC_GET_DEADLINE:

		return sw_sync_ioctl_get_deadline(obj, arg);



	default:

		return -ENOTTY;

	}

drivers/dma-buf/sync_debug.h

+2 −0
Original line number Diff line number Diff line
@@ -55,11 +55,13 @@ static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence) 
 * @base: base fence object

 * @link: link on the sync timeline's list

 * @node: node in the sync timeline's tree

 * @deadline: the earliest fence deadline hint

 */

struct sync_pt {

	struct dma_fence base;

	struct list_head link;

	struct rb_node node;

	ktime_t deadline;

};



extern const struct file_operations sw_sync_debugfs_fops;