[PATCH v10 15/17] media: uapi: HEVC: fix padding in v4l2 control structures

From: Benjamin Gaignard
Date: Tue Jul 05 2022 - 04:55:22 EST


Fix padding where needed to remove holes and stay aligned on cache boundaries

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
Acked-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Tested-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
---
version 9:
- Fix commit message
- Remove useless padding at the end of hevc structures

.../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 8df8d7fdfe70..889e2bcffde6 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -3509,9 +3509,6 @@ 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
@@ -3535,6 +3532,9 @@ 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;
};

--
2.32.0