[Intel-xe] [PATCH 1/5] drm/xe: Allow num_binds == 0 in VM bind IOCTL

[Souza, Jose]

On Thu, 2023-11-16 at 11:40 -0800, Matthew Brost wrote:
> The idea being out-syncs can signal indicating all previous operations
> on the bind queue are complete. An example use case of this would be
> support for implementing vkQueueWaitForIdle easily.

s/vkQueueWaitForIdle/vkQueueWaitIdle

So this is just for the bind queue.
Not sure if it is useful, Mesa will eventually move to async vm bind and we will use a single TIMELINE_SYNCOBJ to track what bind operations are
completed.
Paulo do you see any use with sparse?

> 
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> ---
>  drivers/gpu/drm/xe/xe_vm.c | 30 ++++++++++++++++++------------
>  1 file changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index d45f4f1d490f..cd8c2332a22e 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -2850,7 +2850,6 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe,
>  	int i;
>  
>  	if (XE_IOCTL_DBG(xe, args->extensions) ||
> -	    XE_IOCTL_DBG(xe, !args->num_binds) ||
>  	    XE_IOCTL_DBG(xe, args->num_binds > MAX_BINDS))
>  		return -EINVAL;
>  
> @@ -2977,7 +2976,7 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  			goto put_exec_queue;
>  		}
>  
> -		if (XE_IOCTL_DBG(xe, async !=
> +		if (XE_IOCTL_DBG(xe, args->num_binds && async !=
>  				 !!(q->flags & EXEC_QUEUE_FLAG_VM_ASYNC))) {
>  			err = -EINVAL;
>  			goto put_exec_queue;
> @@ -2991,7 +2990,7 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  	}
>  
>  	if (!args->exec_queue_id) {
> -		if (XE_IOCTL_DBG(xe, async !=
> +		if (XE_IOCTL_DBG(xe, args->num_binds && async !=
>  				 !!(vm->flags & XE_VM_FLAG_ASYNC_DEFAULT))) {
>  			err = -EINVAL;
>  			goto put_vm;
> @@ -3028,16 +3027,18 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  		}
>  	}
>  
> -	bos = kzalloc(sizeof(*bos) * args->num_binds, GFP_KERNEL);
> -	if (!bos) {
> -		err = -ENOMEM;
> -		goto release_vm_lock;
> -	}
> +	if (args->num_binds) {
> +		bos = kzalloc(sizeof(*bos) * args->num_binds, GFP_KERNEL);
> +		if (!bos) {
> +			err = -ENOMEM;
> +			goto release_vm_lock;
> +		}
>  
> -	ops = kzalloc(sizeof(*ops) * args->num_binds, GFP_KERNEL);
> -	if (!ops) {
> -		err = -ENOMEM;
> -		goto release_vm_lock;
> +		ops = kzalloc(sizeof(*ops) * args->num_binds, GFP_KERNEL);
> +		if (!ops) {
> +			err = -ENOMEM;
> +			goto release_vm_lock;
> +		}
>  	}
>  
>  	for (i = 0; i < args->num_binds; ++i) {
> @@ -3092,6 +3093,11 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  			goto free_syncs;
>  	}
>  
> +	if (!args->num_binds) {
> +		err = -ENODATA;
> +		goto free_syncs;
> +	}
> +
>  	for (i = 0; i < args->num_binds; ++i) {
>  		u64 range = bind_ops[i].range;
>  		u64 addr = bind_ops[i].addr;