Re: [PATCH v11 15/17] media: uapi: HEVC: fix padding in v4l2 control structures

Hans Verkuil
2022-07-08T07:03:37Z

On 7/6/22 11:38, Benjamin Gaignard wrote:
> Fix padding where needed to remove holes and stay aligned on cache boundaries

If a v12 is needed, then please drop the " and stay aligned on cache boundaries"
part since that's a left-over from previous versions. I've manually removed it
in my branch so no need to do anything unless a v12 is needed.

Regards,

Hans

>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> Acked-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> Tested-by: Jernej Skrabec <jernej.skrabec@gmail.com>
> ---
> .../media/v4l/ext-ctrls-codec.rst | 6 ++---
> drivers/media/v4l2-core/v4l2-ctrls-core.c | 15 -------------
> include/media/hevc-ctrls.h | 22 ++++++++++++-------
> 3 files changed, 17 insertions(+), 26 deletions(-)
>
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index 59e751c38d06..d5ef91ae3539 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -3513,9 +3513,6 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> * - __u8
> - ``num_active_dpb_entries``
> - The number of entries in ``dpb``.
> - * - struct :c:type:`v4l2_hevc_dpb_entry`
> - - ``dpb[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
> - - The decoded picture buffer, for meta-data about reference frames.
> * - __u8
> - ``num_poc_st_curr_before``
> - The number of reference pictures in the short-term set that come before
> @@ -3539,6 +3536,9 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> - ``poc_lt_curr[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
> - PocLtCurr as described in section 8.3.2 "Decoding process for reference
> picture set": provides the index of the long term references in DPB array.
> + * - struct :c:type:`v4l2_hevc_dpb_entry`
> + - ``dpb[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
> + - The decoded picture buffer, for meta-data about reference frames.
> * - __u64
> - ``flags``
> - See :ref:`Decode Parameters Flags <hevc_decode_params_flags>`
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> index c5c5407584ff..1f85828d6694 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> @@ -536,7 +536,6 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> struct v4l2_ctrl_h264_decode_params *p_h264_dec_params;
> struct v4l2_ctrl_hevc_sps *p_hevc_sps;
> struct v4l2_ctrl_hevc_pps *p_hevc_pps;
> - struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
> struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
> struct v4l2_ctrl_hevc_decode_params *p_hevc_decode_params;
> struct v4l2_area *area;
> @@ -814,8 +813,6 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> p_hevc_pps->pps_beta_offset_div2 = 0;
> p_hevc_pps->pps_tc_offset_div2 = 0;
> }
> -
> - zero_padding(*p_hevc_pps);
> break;
>
> case V4L2_CTRL_TYPE_HEVC_DECODE_PARAMS:
> @@ -824,21 +821,9 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> if (p_hevc_decode_params->num_active_dpb_entries >
> V4L2_HEVC_DPB_ENTRIES_NUM_MAX)
> return -EINVAL;
> -
> - for (i = 0; i < p_hevc_decode_params->num_active_dpb_entries;
> - i++) {
> - struct v4l2_hevc_dpb_entry *dpb_entry =
> - &p_hevc_decode_params->dpb[i];
> -
> - zero_padding(*dpb_entry);
> - }
> break;
>
> case V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS:
> - p_hevc_slice_params = p;
> -
> - zero_padding(p_hevc_slice_params->pred_weight_table);
> - zero_padding(*p_hevc_slice_params);
> break;
>
> case V4L2_CTRL_TYPE_HDR10_CLL_INFO:
> diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
> index 9239e8b649e0..7358cbfc3e4d 100644
> --- a/include/media/hevc-ctrls.h
> +++ b/include/media/hevc-ctrls.h
> @@ -105,6 +105,7 @@ enum v4l2_stateless_hevc_start_code {
> * @chroma_format_idc: specifies the chroma sampling
> * @sps_max_sub_layers_minus1: this value plus 1 specifies the maximum number
> * of temporal sub-layers
> + * @reserved: padding field. Should be zeroed by applications.
> * @flags: see V4L2_HEVC_SPS_FLAG_{}
> */
> struct v4l2_ctrl_hevc_sps {
> @@ -133,6 +134,7 @@ struct v4l2_ctrl_hevc_sps {
> __u8 chroma_format_idc;
> __u8 sps_max_sub_layers_minus1;
>
> + __u8 reserved[6];
> __u64 flags;
> };
>
> @@ -192,6 +194,7 @@ struct v4l2_ctrl_hevc_sps {
> * divided by 2
> * @log2_parallel_merge_level_minus2: this value plus 2 specifies the value of
> * the variable Log2ParMrgLevel
> + * @reserved: padding field. Should be zeroed by applications.
> * @flags: see V4L2_HEVC_PPS_FLAG_{}
> */
> struct v4l2_ctrl_hevc_pps {
> @@ -210,8 +213,7 @@ struct v4l2_ctrl_hevc_pps {
> __s8 pps_beta_offset_div2;
> __s8 pps_tc_offset_div2;
> __u8 log2_parallel_merge_level_minus2;
> -
> - __u8 padding[4];
> + __u8 reserved;
> __u64 flags;
> };
>
> @@ -239,14 +241,15 @@ struct v4l2_ctrl_hevc_pps {
> * @timestamp: timestamp of the V4L2 capture buffer to use as reference.
> * @flags: long term flag for the reference frame
> * @field_pic: whether the reference is a field picture or a frame.
> + * @reserved: padding field. Should be zeroed by applications.
> * @pic_order_cnt_val: the picture order count of the reference.
> */
> struct v4l2_hevc_dpb_entry {
> __u64 timestamp;
> __u8 flags;
> __u8 field_pic;
> + __u16 reserved;
> __s32 pic_order_cnt_val;
> - __u8 padding[2];
> };
>
> /**
> @@ -285,8 +288,6 @@ struct v4l2_hevc_pred_weight_table {
> __s8 delta_chroma_weight_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX][2];
> __s8 chroma_offset_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX][2];
>
> - __u8 padding[6];
> -
> __u8 luma_log2_weight_denom;
> __s8 delta_chroma_log2_weight_denom;
> };
> @@ -339,6 +340,7 @@ struct v4l2_hevc_pred_weight_table {
> * @slice_tc_offset_div2: specify the deblocking parameter offsets for tC divided by 2
> * @pic_struct: indicates whether a picture should be displayed as a frame or as one or
> * more fields
> + * @reserved0: padding field. Should be zeroed by applications.
> * @slice_segment_addr: specifies the address of the first coding tree block in
> * the slice segment
> * @ref_idx_l0: the list of L0 reference elements as indices in the DPB
> @@ -349,6 +351,7 @@ struct v4l2_hevc_pred_weight_table {
> * picture include in the SPS
> * @pred_weight_table: the prediction weight coefficients for inter-picture
> * prediction
> + * @reserved1: padding field. Should be zeroed by applications.
> * @flags: see V4L2_HEVC_SLICE_PARAMS_FLAG_{}
> */
> struct v4l2_ctrl_hevc_slice_params {
> @@ -379,17 +382,18 @@ struct v4l2_ctrl_hevc_slice_params {
> /* ISO/IEC 23008-2, ITU-T Rec. H.265: Picture timing SEI message */
> __u8 pic_struct;
>
> + __u8 reserved0[3];
> /* ISO/IEC 23008-2, ITU-T Rec. H.265: General slice segment header */
> __u32 slice_segment_addr;
> __u8 ref_idx_l0[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> __u8 ref_idx_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> __u16 short_term_ref_pic_set_size;
> __u16 long_term_ref_pic_set_size;
> - __u8 padding;
>
> /* ISO/IEC 23008-2, ITU-T Rec. H.265: Weighted prediction parameter */
> struct v4l2_hevc_pred_weight_table pred_weight_table;
>
> + __u8 reserved1[2];
> __u64 flags;
> };
>
> @@ -406,7 +410,6 @@ struct v4l2_ctrl_hevc_slice_params {
> * @long_term_ref_pic_set_size: specifies the size of long-term reference
> * pictures set include in the SPS of the first slice
> * @num_active_dpb_entries: the number of entries in dpb
> - * @dpb: the decoded picture buffer, for meta-data about reference frames
> * @num_poc_st_curr_before: the number of reference pictures in the short-term
> * set that come before the current frame
> * @num_poc_st_curr_after: the number of reference pictures in the short-term
> @@ -417,6 +420,8 @@ struct v4l2_ctrl_hevc_slice_params {
> * @poc_st_curr_after: provides the index of the short term after references
> * in DPB array
> * @poc_lt_curr: provides the index of the long term references in DPB array
> + * @reserved: padding field. Should be zeroed by applications.
> + * @dpb: the decoded picture buffer, for meta-data about reference frames
> * @flags: see V4L2_HEVC_DECODE_PARAM_FLAG_{}
> */
> struct v4l2_ctrl_hevc_decode_params {
> @@ -424,13 +429,14 @@ struct v4l2_ctrl_hevc_decode_params {
> __u16 short_term_ref_pic_set_size;
> __u16 long_term_ref_pic_set_size;
> __u8 num_active_dpb_entries;
> - struct v4l2_hevc_dpb_entry dpb[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> __u8 num_poc_st_curr_before;
> __u8 num_poc_st_curr_after;
> __u8 num_poc_lt_curr;
> __u8 poc_st_curr_before[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> __u8 poc_st_curr_after[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> __u8 poc_lt_curr[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> + __u8 reserved[4];
> + struct v4l2_hevc_dpb_entry dpb[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> __u64 flags;
> };
>