Re: [PATCH 4/8] v4l2-ctrls: allocate space for arrays

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

Thank you for the patch.

On Tue, Jun 28, 2022 at 02:05:19PM +0200, Hans Verkuil wrote:
> Just like dynamic arrays, also allocate space for regular arrays.
> 
> This is in preparation for allowing to change the array size from
> a driver.
> 
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

> ---
>  drivers/media/v4l2-core/v4l2-ctrls-api.c  |  8 +++---
>  drivers/media/v4l2-core/v4l2-ctrls-core.c | 33 +++++++++++------------
>  include/media/v4l2-ctrls.h                | 17 ++++++------
>  3 files changed, 28 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c
> index 50d012ba3c02..1b90bd7c4010 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-api.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c
> @@ -105,8 +105,8 @@ static int user_to_new(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
>  
>  	ctrl->is_new = 0;
>  	if (ctrl->is_dyn_array &&
> -	    c->size > ctrl->p_dyn_alloc_elems * ctrl->elem_size) {
> -		void *old = ctrl->p_dyn;
> +	    c->size > ctrl->p_array_alloc_elems * ctrl->elem_size) {
> +		void *old = ctrl->p_array;
>  		void *tmp = kvzalloc(2 * c->size, GFP_KERNEL);
>  
>  		if (!tmp)
> @@ -115,8 +115,8 @@ static int user_to_new(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
>  		memcpy(tmp + c->size, ctrl->p_cur.p, ctrl->elems * ctrl->elem_size);
>  		ctrl->p_new.p = tmp;
>  		ctrl->p_cur.p = tmp + c->size;
> -		ctrl->p_dyn = tmp;
> -		ctrl->p_dyn_alloc_elems = c->size / ctrl->elem_size;
> +		ctrl->p_array = tmp;
> +		ctrl->p_array_alloc_elems = c->size / ctrl->elem_size;
>  		kvfree(old);
>  	}
>  
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> index ff8a61f24d0a..1372b7b45681 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> @@ -1135,14 +1135,14 @@ int req_to_new(struct v4l2_ctrl_ref *ref)
>  
>  	/*
>  	 * Check if the number of elements in the request is more than the
> -	 * elements in ctrl->p_dyn. If so, attempt to realloc ctrl->p_dyn.
> -	 * Note that p_dyn is allocated with twice the number of elements
> +	 * elements in ctrl->p_array. If so, attempt to realloc ctrl->p_array.
> +	 * Note that p_array is allocated with twice the number of elements
>  	 * in the dynamic array since it has to store both the current and
>  	 * new value of such a control.
>  	 */
> -	if (ref->p_req_elems > ctrl->p_dyn_alloc_elems) {
> +	if (ref->p_req_elems > ctrl->p_array_alloc_elems) {
>  		unsigned int sz = ref->p_req_elems * ctrl->elem_size;
> -		void *old = ctrl->p_dyn;
> +		void *old = ctrl->p_array;
>  		void *tmp = kvzalloc(2 * sz, GFP_KERNEL);
>  
>  		if (!tmp)
> @@ -1151,8 +1151,8 @@ int req_to_new(struct v4l2_ctrl_ref *ref)
>  		memcpy(tmp + sz, ctrl->p_cur.p, ctrl->elems * ctrl->elem_size);
>  		ctrl->p_new.p = tmp;
>  		ctrl->p_cur.p = tmp + sz;
> -		ctrl->p_dyn = tmp;
> -		ctrl->p_dyn_alloc_elems = ref->p_req_elems;
> +		ctrl->p_array = tmp;
> +		ctrl->p_array_alloc_elems = ref->p_req_elems;
>  		kvfree(old);
>  	}
>  
> @@ -1252,7 +1252,7 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
>  		list_del(&ctrl->node);
>  		list_for_each_entry_safe(sev, next_sev, &ctrl->ev_subs, node)
>  			list_del(&sev->node);
> -		kvfree(ctrl->p_dyn);
> +		kvfree(ctrl->p_array);
>  		kvfree(ctrl);
>  	}
>  	kvfree(hdl->buckets);
> @@ -1584,11 +1584,10 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  			V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
>  	else if (type == V4L2_CTRL_TYPE_CTRL_CLASS)
>  		flags |= V4L2_CTRL_FLAG_READ_ONLY;
> -	else if (!(flags & V4L2_CTRL_FLAG_DYNAMIC_ARRAY) &&
> +	else if (!is_array &&
>  		 (type == V4L2_CTRL_TYPE_INTEGER64 ||
>  		  type == V4L2_CTRL_TYPE_STRING ||
> -		  type >= V4L2_CTRL_COMPOUND_TYPES ||
> -		  is_array))
> +		  type >= V4L2_CTRL_COMPOUND_TYPES))
>  		sz_extra += 2 * tot_ctrl_size;
>  
>  	if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p_const)
> @@ -1632,14 +1631,14 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	ctrl->cur.val = ctrl->val = def;
>  	data = &ctrl[1];
>  
> -	if (ctrl->is_dyn_array) {
> -		ctrl->p_dyn_alloc_elems = elems;
> -		ctrl->p_dyn = kvzalloc(2 * elems * elem_size, GFP_KERNEL);
> -		if (!ctrl->p_dyn) {
> +	if (ctrl->is_array) {
> +		ctrl->p_array_alloc_elems = elems;
> +		ctrl->p_array = kvzalloc(2 * elems * elem_size, GFP_KERNEL);
> +		if (!ctrl->p_array) {
>  			kvfree(ctrl);
>  			return NULL;
>  		}
> -		data = ctrl->p_dyn;
> +		data = ctrl->p_array;
>  	}
>  
>  	if (!ctrl->is_int) {
> @@ -1651,7 +1650,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	}
>  
>  	if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p_const) {
> -		if (ctrl->is_dyn_array)
> +		if (ctrl->is_array)
>  			ctrl->p_def.p = &ctrl[1];
>  		else
>  			ctrl->p_def.p = ctrl->p_cur.p + tot_ctrl_size;
> @@ -1664,7 +1663,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	}
>  
>  	if (handler_new_ref(hdl, ctrl, NULL, false, false)) {
> -		kvfree(ctrl->p_dyn);
> +		kvfree(ctrl->p_array);
>  		kvfree(ctrl);
>  		return NULL;
>  	}
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index f4105de8a8d2..a2f147873265 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -209,7 +209,7 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
>   * @elem_size:	The size in bytes of the control.
>   * @new_elems:	The number of elements in p_new. This is the same as @elems,
>   *		except for dynamic arrays. In that case it is in the range of
> - *		1 to @p_dyn_alloc_elems.
> + *		1 to @p_array_alloc_elems.
>   * @dims:	The size of each dimension.
>   * @nr_of_dims:The number of dimensions in @dims.
>   * @menu_skip_mask: The control's skip mask for menu controls. This makes it
> @@ -233,12 +233,11 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
>   *		not freed when the control is deleted. Should this be needed
>   *		then a new internal bitfield can be added to tell the framework
>   *		to free this pointer.
> - * @p_dyn:	Pointer to the dynamically allocated array. Only valid if
> - *		@is_dyn_array is true.
> - * @p_dyn_alloc_elems: The number of elements in the dynamically allocated
> - *		array for both the cur and new values. So @p_dyn is actually
> - *		sized for 2 * @p_dyn_alloc_elems * @elem_size. Only valid if
> - *		@is_dyn_array is true.
> + * @p_array:	Pointer to the allocated array. Only valid if @is_array is true.
> + * @p_array_alloc_elems: The number of elements in the allocated
> + *		array for both the cur and new values. So @p_array is actually
> + *		sized for 2 * @p_array_alloc_elems * @elem_size. Only valid if
> + *		@is_array is true.
>   * @cur:	Structure to store the current value.
>   * @cur.val:	The control's current value, if the @type is represented via
>   *		a u32 integer (see &enum v4l2_ctrl_type).
> @@ -297,8 +296,8 @@ struct v4l2_ctrl {
>  	};
>  	unsigned long flags;
>  	void *priv;
> -	void *p_dyn;
> -	u32 p_dyn_alloc_elems;
> +	void *p_array;
> +	u32 p_array_alloc_elems;
>  	s32 val;
>  	struct {
>  		s32 val;

-- 
Regards,

Laurent Pinchart