Re: [PATCH v4 07/14] dma-buf/sw_sync: Add fence deadline support

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 18.02.23 um 22:15 schrieb Rob Clark:
> From: Rob Clark <robdclark@chromium.org>
>
> 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.
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/dma-buf/sw_sync.c    | 58 ++++++++++++++++++++++++++++++++++++
>   drivers/dma-buf/sync_debug.h |  2 ++
>   2 files changed, 60 insertions(+)
>
> diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
> index 348b3a9170fa..50f2638cccd3 100644
> --- a/drivers/dma-buf/sw_sync.c
> +++ b/drivers/dma-buf/sw_sync.c
> @@ -52,12 +52,26 @@ struct sw_sync_create_fence_data {
>   	__s32	fence; /* fd of new fence */
>   };
>   
> +/**
> + * struct sw_sync_get_deadline - get the deadline of a sw_sync fence
> + * @tv_sec:	seconds elapsed since epoch (out)
> + * @tv_nsec:	nanoseconds elapsed since the time given by the tv_sec (out)
> + * @fence_fd:	the sw_sync fence fd (in)
> + */
> +struct sw_sync_get_deadline {
> +	__s64	tv_sec;
> +	__s32	tv_nsec;
> +	__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)
>   
>   static const struct dma_fence_ops timeline_fence_ops;
>   
> @@ -171,6 +185,13 @@ 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);
> +
> +	pt->deadline = deadline;
> +}
> +
>   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 +200,7 @@ 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 +409,39 @@ 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 timespec64 ts;
> +	struct dma_fence *fence;
> +	struct sync_pt *pt;
> +
> +	if (copy_from_user(&data, (void __user *)arg, sizeof(data)))
> +		return -EFAULT;
> +
> +	if (data.tv_sec || data.tv_nsec)
> +		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;
> +
> +	ts = ktime_to_timespec64(pt->deadline);
> +	data.tv_sec  = ts.tv_sec;
> +	data.tv_nsec = ts.tv_nsec;
> +
> +	dma_fence_put(fence);
> +
> +	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 +454,9 @@ 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;
>   	}
> diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
> index 6176e52ba2d7..2e0146d0bdbb 100644
> --- a/drivers/dma-buf/sync_debug.h
> +++ b/drivers/dma-buf/sync_debug.h
> @@ -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 most recently set fence deadline
>    */
>   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;