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Message-ID: <e10817d425d93e89d7c957a8084606f8e4a655c8.camel@ndufresne.ca>
Subject: Re: [PATCH v3 06/15] media: mtk-vcodec: vdec: support stateless
 H.264 decoding
From:   Nicolas Dufresne <nicolas@ndufresne.ca>
To:     Alexandre Courbot <acourbot@chromium.org>,
        Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>,
        Yunfei Dong <yunfei.dong@mediatek.com>
Cc:     Tiffany Lin <tiffany.lin@mediatek.com>,
        Andrew-CT Chen <andrew-ct.chen@mediatek.com>,
        Rob Herring <robh+dt@kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        linux-media <linux-media@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>
Date:   Mon, 15 Mar 2021 11:21:04 -0400
In-Reply-To: <CAPBb6MWrbzQMuNNYgjwcEg4_oapMHtjDvAtKkTtAvDqr3AVO9w@mail.gmail.com>
References: <20210226100148.1663389-1-acourbot@chromium.org>
         <20210226100148.1663389-7-acourbot@chromium.org>
         <CAAEAJfBRoOgT9waWjfK7uxFF+QCO+Cv0H22Z4V1p86G1wTt_Hw@mail.gmail.com>
         <CAPBb6MWrbzQMuNNYgjwcEg4_oapMHtjDvAtKkTtAvDqr3AVO9w@mail.gmail.com>
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Le lundi 15 mars 2021 à 20:28 +0900, Alexandre Courbot a écrit :
> Hi Ezequiel,
> 
> On Thu, Mar 4, 2021 at 6:47 AM Ezequiel Garcia
> <ezequiel@vanguardiasur.com.ar> wrote:
> > 
> >  Hi Alex,
> > 
> > Thanks for the patch.
> > 
> > On Fri, 26 Feb 2021 at 07:06, Alexandre Courbot <acourbot@chromium.org>
> > wrote:
> > > 
> > > From: Yunfei Dong <yunfei.dong@mediatek.com>
> > > 
> > > Add support for H.264 decoding using the stateless API, as supported by
> > > MT8183. This support takes advantage of the V4L2 H.264 reference list
> > > builders.
> > > 
> > > Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> > > [acourbot: refactor, cleanup and split]
> > > Co-developed-by: Alexandre Courbot <acourbot@chromium.org>
> > > Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> > > ---
> > >  drivers/media/platform/Kconfig                |   1 +
> > >  drivers/media/platform/mtk-vcodec/Makefile    |   1 +
> > >  .../mtk-vcodec/vdec/vdec_h264_req_if.c        | 807 ++++++++++++++++++
> > >  .../media/platform/mtk-vcodec/vdec_drv_if.c   |   3 +
> > >  .../media/platform/mtk-vcodec/vdec_drv_if.h   |   1 +
> > >  5 files changed, 813 insertions(+)
> > >  create mode 100644 drivers/media/platform/mtk-
> > > vcodec/vdec/vdec_h264_req_if.c
> > > 
> > > diff --git a/drivers/media/platform/Kconfig
> > > b/drivers/media/platform/Kconfig
> > > index fd1831e97b22..c27db5643712 100644
> > > --- a/drivers/media/platform/Kconfig
> > > +++ b/drivers/media/platform/Kconfig
> > > @@ -295,6 +295,7 @@ config VIDEO_MEDIATEK_VCODEC
> > >         select V4L2_MEM2MEM_DEV
> > >         select VIDEO_MEDIATEK_VCODEC_VPU if VIDEO_MEDIATEK_VPU
> > >         select VIDEO_MEDIATEK_VCODEC_SCP if MTK_SCP
> > > +       select V4L2_H264
> > >         help
> > >           Mediatek video codec driver provides HW capability to
> > >           encode and decode in a range of video formats on MT8173
> > > diff --git a/drivers/media/platform/mtk-vcodec/Makefile
> > > b/drivers/media/platform/mtk-vcodec/Makefile
> > > index 4ba93d838ab6..ca8e9e7a9c4e 100644
> > > --- a/drivers/media/platform/mtk-vcodec/Makefile
> > > +++ b/drivers/media/platform/mtk-vcodec/Makefile
> > > @@ -7,6 +7,7 @@ obj-$(CONFIG_VIDEO_MEDIATEK_VCODEC) += mtk-vcodec-dec.o \
> > >  mtk-vcodec-dec-y := vdec/vdec_h264_if.o \
> > >                 vdec/vdec_vp8_if.o \
> > >                 vdec/vdec_vp9_if.o \
> > > +               vdec/vdec_h264_req_if.o \
> > >                 mtk_vcodec_dec_drv.o \
> > >                 vdec_drv_if.o \
> > >                 vdec_vpu_if.o \
> > > diff --git a/drivers/media/platform/mtk-vcodec/vdec/vdec_h264_req_if.c
> > > b/drivers/media/platform/mtk-vcodec/vdec/vdec_h264_req_if.c
> > > new file mode 100644
> > > index 000000000000..2fbbfbbcfbec
> > > --- /dev/null
> > > +++ b/drivers/media/platform/mtk-vcodec/vdec/vdec_h264_req_if.c
> > > @@ -0,0 +1,807 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +#include <linux/module.h>
> > > +#include <linux/slab.h>
> > > +#include <media/v4l2-mem2mem.h>
> > > +#include <media/v4l2-h264.h>
> > > +#include <media/videobuf2-dma-contig.h>
> > > +
> > > +#include "../vdec_drv_if.h"
> > > +#include "../mtk_vcodec_util.h"
> > > +#include "../mtk_vcodec_dec.h"
> > > +#include "../mtk_vcodec_intr.h"
> > > +#include "../vdec_vpu_if.h"
> > > +#include "../vdec_drv_base.h"
> > > +
> > > +#define NAL_NON_IDR_SLICE                      0x01
> > > +#define NAL_IDR_SLICE                          0x05
> > > +#define NAL_H264_PPS                           0x08
> > 
> > Not used?
> > 
> > > +#define NAL_TYPE(value)                                ((value) & 0x1F)
> > > +
> > 
> > I believe you may not need the NAL type.
> 
> True, removed this block of defines.
> 
> > 
> > > +#define BUF_PREDICTION_SZ                      (64 * 4096)
> > > +#define MB_UNIT_LEN                            16
> > > +
> > > +/* get used parameters for sps/pps */
> > > +#define GET_MTK_VDEC_FLAG(cond, flag) \
> > > +       { dst_param->cond = ((src_param->flags & flag) ? (1) : (0)); }
> > > +#define GET_MTK_VDEC_PARAM(param) \
> > > +       { dst_param->param = src_param->param; }
> > > +/* motion vector size (bytes) for every macro block */
> > > +#define HW_MB_STORE_SZ                         64
> > > +
> > > +#define H264_MAX_FB_NUM                                17
> > > +#define H264_MAX_MV_NUM                                32
> > > +#define HDR_PARSING_BUF_SZ                     1024
> > > +
> > > +/**
> > > + * struct mtk_h264_dpb_info  - h264 dpb information
> > > + * @y_dma_addr: Y bitstream physical address
> > > + * @c_dma_addr: CbCr bitstream physical address
> > > + * @reference_flag: reference picture flag (short/long term reference
> > > picture)
> > > + * @field: field picture flag
> > > + */
> > > +struct mtk_h264_dpb_info {
> > > +       dma_addr_t y_dma_addr;
> > > +       dma_addr_t c_dma_addr;
> > > +       int reference_flag;
> > > +       int field;
> > > +};
> > > +
> > > +/**
> > > + * struct mtk_h264_sps_param  - parameters for sps
> > > + */
> > > +struct mtk_h264_sps_param {
> > > +       unsigned char chroma_format_idc;
> > > +       unsigned char bit_depth_luma_minus8;
> > > +       unsigned char bit_depth_chroma_minus8;
> > > +       unsigned char log2_max_frame_num_minus4;
> > > +       unsigned char pic_order_cnt_type;
> > > +       unsigned char log2_max_pic_order_cnt_lsb_minus4;
> > > +       unsigned char max_num_ref_frames;
> > > +       unsigned char separate_colour_plane_flag;
> > > +       unsigned short pic_width_in_mbs_minus1;
> > > +       unsigned short pic_height_in_map_units_minus1;
> > > +       unsigned int max_frame_nums;
> > > +       unsigned char qpprime_y_zero_transform_bypass_flag;
> > > +       unsigned char delta_pic_order_always_zero_flag;
> > > +       unsigned char frame_mbs_only_flag;
> > > +       unsigned char mb_adaptive_frame_field_flag;
> > > +       unsigned char direct_8x8_inference_flag;
> > > +       unsigned char reserved[3];
> > > +};
> > > +
> > > +/**
> > > + * struct mtk_h264_pps_param  - parameters for pps
> > > + */
> > > +struct mtk_h264_pps_param {
> > > +       unsigned char num_ref_idx_l0_default_active_minus1;
> > > +       unsigned char num_ref_idx_l1_default_active_minus1;
> > > +       unsigned char weighted_bipred_idc;
> > > +       char pic_init_qp_minus26;
> > > +       char chroma_qp_index_offset;
> > > +       char second_chroma_qp_index_offset;
> > > +       unsigned char entropy_coding_mode_flag;
> > > +       unsigned char pic_order_present_flag;
> > > +       unsigned char deblocking_filter_control_present_flag;
> > > +       unsigned char constrained_intra_pred_flag;
> > > +       unsigned char weighted_pred_flag;
> > > +       unsigned char redundant_pic_cnt_present_flag;
> > > +       unsigned char transform_8x8_mode_flag;
> > > +       unsigned char scaling_matrix_present_flag;
> > > +       unsigned char reserved[2];
> > > +};
> > > +
> > > +struct slice_api_h264_scaling_matrix {
> > 
> > Equal to v4l2_ctrl_h264_scaling_matrix ?
> > Well I guess you don't want to mix a hardware-specific
> > thing with the V4L2 API maybe.
> 
> That's the idea. Although the layout match and the ABI is now stable,
> I think this communicates better the fact that this is a firmware
> structure.
> 
> > 
> > > +       unsigned char scaling_list_4x4[6][16];
> > > +       unsigned char scaling_list_8x8[6][64];
> > > +};
> > > +
> > > +struct slice_h264_dpb_entry {
> > > +       unsigned long long reference_ts;
> > > +       unsigned short frame_num;
> > > +       unsigned short pic_num;
> > > +       /* Note that field is indicated by v4l2_buffer.field */
> > > +       int top_field_order_cnt;
> > > +       int bottom_field_order_cnt;
> > > +       unsigned int flags; /* V4L2_H264_DPB_ENTRY_FLAG_* */
> > > +};
> > > +
> > > +/**
> > > + * struct slice_api_h264_decode_param - parameters for decode.
> > > + */
> > > +struct slice_api_h264_decode_param {
> > > +       struct slice_h264_dpb_entry dpb[16];
> > 
> > V4L2_H264_NUM_DPB_ENTRIES?
> 
> For the same reason as above (this being a firmware structure), I
> think it is clearer to not use the kernel definitions here.
> 
> > 
> > > +       unsigned short num_slices;
> > > +       unsigned short nal_ref_idc;
> > > +       unsigned char ref_pic_list_p0[32];
> > > +       unsigned char ref_pic_list_b0[32];
> > > +       unsigned char ref_pic_list_b1[32];
> > 
> > V4L2_H264_REF_LIST_LEN?
> 
> Ditto.
> 
> > 
> > > +       int top_field_order_cnt;
> > > +       int bottom_field_order_cnt;
> > > +       unsigned int flags; /* V4L2_H264_DECODE_PARAM_FLAG_* */
> > > +};
> > > +
> > > +/**
> > > + * struct mtk_h264_dec_slice_param  - parameters for decode current frame
> > > + */
> > > +struct mtk_h264_dec_slice_param {
> > > +       struct mtk_h264_sps_param                       sps;
> > > +       struct mtk_h264_pps_param                       pps;
> > > +       struct slice_api_h264_scaling_matrix            scaling_matrix;
> > > +       struct slice_api_h264_decode_param              decode_params;
> > > +       struct mtk_h264_dpb_info h264_dpb_info[16];
> > 
> > V4L2_H264_NUM_DPB_ENTRIES?
> 
> Ditto.
> 
> > 
> > > +};
> > > +
> > > +/**
> > > + * struct h264_fb - h264 decode frame buffer information
> > > + * @vdec_fb_va  : virtual address of struct vdec_fb
> > > + * @y_fb_dma    : dma address of Y frame buffer (luma)
> > > + * @c_fb_dma    : dma address of C frame buffer (chroma)
> > > + * @poc         : picture order count of frame buffer
> > > + * @reserved    : for 8 bytes alignment
> > > + */
> > > +struct h264_fb {
> > > +       uint64_t vdec_fb_va;
> > > +       uint64_t y_fb_dma;
> > > +       uint64_t c_fb_dma;
> > > +       int32_t poc;
> > > +       uint32_t reserved;
> > > +};
> > > +
> > > +/**
> > > + * struct vdec_h264_dec_info - decode information
> > > + * @dpb_sz             : decoding picture buffer size
> > > + * @resolution_changed  : resoltion change happen
> > > + * @realloc_mv_buf     : flag to notify driver to re-allocate mv buffer
> > > + * @cap_num_planes     : number planes of capture buffer
> > > + * @bs_dma             : Input bit-stream buffer dma address
> > > + * @y_fb_dma           : Y frame buffer dma address
> > > + * @c_fb_dma           : C frame buffer dma address
> > > + * @vdec_fb_va         : VDEC frame buffer struct virtual address
> > > + */
> > > +struct vdec_h264_dec_info {
> > > +       uint32_t dpb_sz;
> > > +       uint32_t resolution_changed;
> > > +       uint32_t realloc_mv_buf;
> > > +       uint32_t cap_num_planes;
> > > +       uint64_t bs_dma;
> > > +       uint64_t y_fb_dma;
> > > +       uint64_t c_fb_dma;
> > > +       uint64_t vdec_fb_va;
> > > +};
> > > +
> > > +/**
> > > + * struct vdec_h264_vsi - shared memory for decode information exchange
> > > + *                        between VPU and Host.
> > > + *                        The memory is allocated by VPU then mapping to
> > > Host
> > > + *                        in vpu_dec_init() and freed in vpu_dec_deinit()
> > > + *                        by VPU.
> > > + *                        AP-W/R : AP is writer/reader on this item
> > > + *                        VPU-W/R: VPU is write/reader on this item
> > > + * @pred_buf_dma : HW working predication buffer dma address (AP-W, VPU-
> > > R)
> > > + * @mv_buf_dma   : HW working motion vector buffer dma address (AP-W,
> > > VPU-R)
> > > + * @dec          : decode information (AP-R, VPU-W)
> > > + * @pic          : picture information (AP-R, VPU-W)
> > > + * @crop         : crop information (AP-R, VPU-W)
> > > + */
> > > +struct vdec_h264_vsi {
> > > +       uint64_t pred_buf_dma;
> > > +       uint64_t mv_buf_dma[H264_MAX_MV_NUM];
> > > +       struct vdec_h264_dec_info dec;
> > > +       struct vdec_pic_info pic;
> > > +       struct v4l2_rect crop;
> > > +       struct mtk_h264_dec_slice_param h264_slice_params;
> > > +};
> > > +
> > > +/**
> > > + * struct vdec_h264_slice_inst - h264 decoder instance
> > > + * @num_nalu : how many nalus be decoded
> > > + * @ctx      : point to mtk_vcodec_ctx
> > > + * @pred_buf : HW working predication buffer
> > > + * @mv_buf   : HW working motion vector buffer
> > > + * @vpu      : VPU instance
> > > + * @vsi_ctx  : Local VSI data for this decoding context
> > > + */
> > > +struct vdec_h264_slice_inst {
> > > +       unsigned int num_nalu;
> > > +       struct mtk_vcodec_ctx *ctx;
> > > +       struct mtk_vcodec_mem pred_buf;
> > > +       struct mtk_vcodec_mem mv_buf[H264_MAX_MV_NUM];
> > > +       struct vdec_vpu_inst vpu;
> > > +       struct vdec_h264_vsi vsi_ctx;
> > > +       struct mtk_h264_dec_slice_param h264_slice_param;
> > > +
> > > +       struct v4l2_h264_dpb_entry dpb[16];
> > > +};
> > > +
> > > +static void *get_ctrl_ptr(struct mtk_vcodec_ctx *ctx,
> > > +                                int id)
> > > +{
> > > +       struct v4l2_ctrl *ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl, id);
> > > +
> > > +       return ctrl->p_cur.p;
> > > +}
> > > +
> > > +static void get_h264_dpb_list(struct vdec_h264_slice_inst *inst,
> > > +                             struct mtk_h264_dec_slice_param
> > > *slice_param)
> > > +{
> > > +       struct vb2_queue *vq;
> > > +       struct vb2_buffer *vb;
> > > +       struct vb2_v4l2_buffer *vb2_v4l2;
> > > +       u64 index;
> > > +
> > > +       vq = v4l2_m2m_get_vq(inst->ctx->m2m_ctx,
> > > +               V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
> > > +
> > > +       for (index = 0; index < 16; index++) {
> > 
> > Ditto, some macro instead of 16.
> 
> Changed this to use ARRAY_SIZE() which is appropriate here.
> 
> > 
> > > +               const struct slice_h264_dpb_entry *dpb;
> > > +               int vb2_index;
> > > +
> > > +               dpb = &slice_param->decode_params.dpb[index];
> > > +               if (!(dpb->flags & V4L2_H264_DPB_ENTRY_FLAG_ACTIVE)) {
> > > +                       slice_param->h264_dpb_info[index].reference_flag =
> > > 0;
> > > +                       continue;
> > > +               }
> > > +
> > > +               vb2_index = vb2_find_timestamp(vq, dpb->reference_ts, 0);
> > > +               if (vb2_index < 0) {
> > > +                       mtk_vcodec_err(inst, "Reference invalid:
> > > dpb_index(%lld) reference_ts(%lld)",
> > > +                               index, dpb->reference_ts);
> > > +                       continue;
> > > +               }
> > > +               /* 1 for short term reference, 2 for long term reference
> > > */
> > > +               if (!(dpb->flags & V4L2_H264_DPB_ENTRY_FLAG_LONG_TERM))
> > > +                       slice_param->h264_dpb_info[index].reference_flag =
> > > 1;
> > > +               else
> > > +                       slice_param->h264_dpb_info[index].reference_flag =
> > > 2;
> > > +
> > > +               vb = vq->bufs[vb2_index];
> > > +               vb2_v4l2 = container_of(vb, struct vb2_v4l2_buffer,
> > > vb2_buf);
> > > +               slice_param->h264_dpb_info[index].field = vb2_v4l2->field;
> > > +
> > > +               slice_param->h264_dpb_info[index].y_dma_addr =
> > > +                       vb2_dma_contig_plane_dma_addr(vb, 0);
> > > +               if (inst->ctx->q_data[MTK_Q_DATA_DST].fmt->num_planes ==
> > > 2) {
> > > +                       slice_param->h264_dpb_info[index].c_dma_addr =
> > > +                               vb2_dma_contig_plane_dma_addr(vb, 1);
> > > +               }
> > > +       }
> > > +}
> > > +
> > > +static void get_h264_sps_parameters(struct mtk_h264_sps_param *dst_param,
> > > +       const struct v4l2_ctrl_h264_sps *src_param)
> > > +{
> > > +       GET_MTK_VDEC_PARAM(chroma_format_idc);
> > > +       GET_MTK_VDEC_PARAM(bit_depth_luma_minus8);
> > > +       GET_MTK_VDEC_PARAM(bit_depth_chroma_minus8);
> > > +       GET_MTK_VDEC_PARAM(log2_max_frame_num_minus4);
> > > +       GET_MTK_VDEC_PARAM(pic_order_cnt_type);
> > > +       GET_MTK_VDEC_PARAM(log2_max_pic_order_cnt_lsb_minus4);
> > > +       GET_MTK_VDEC_PARAM(max_num_ref_frames);
> > > +       GET_MTK_VDEC_PARAM(pic_width_in_mbs_minus1);
> > > +       GET_MTK_VDEC_PARAM(pic_height_in_map_units_minus1);
> > > +
> > > +       GET_MTK_VDEC_FLAG(separate_colour_plane_flag,
> > > +               V4L2_H264_SPS_FLAG_SEPARATE_COLOUR_PLANE);
> > > +       GET_MTK_VDEC_FLAG(qpprime_y_zero_transform_bypass_flag,
> > > +               V4L2_H264_SPS_FLAG_QPPRIME_Y_ZERO_TRANSFORM_BYPASS);
> > > +       GET_MTK_VDEC_FLAG(delta_pic_order_always_zero_flag,
> > > +               V4L2_H264_SPS_FLAG_DELTA_PIC_ORDER_ALWAYS_ZERO);
> > > +       GET_MTK_VDEC_FLAG(frame_mbs_only_flag,
> > > +               V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY);
> > > +       GET_MTK_VDEC_FLAG(mb_adaptive_frame_field_flag,
> > > +               V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD);
> > > +       GET_MTK_VDEC_FLAG(direct_8x8_inference_flag,
> > > +               V4L2_H264_SPS_FLAG_DIRECT_8X8_INFERENCE);
> > > +}
> > > +
> > > +static void get_h264_pps_parameters(struct mtk_h264_pps_param *dst_param,
> > > +       const struct v4l2_ctrl_h264_pps *src_param)
> > > +{
> > > +       GET_MTK_VDEC_PARAM(num_ref_idx_l0_default_active_minus1);
> > > +       GET_MTK_VDEC_PARAM(num_ref_idx_l1_default_active_minus1);
> > > +       GET_MTK_VDEC_PARAM(weighted_bipred_idc);
> > > +       GET_MTK_VDEC_PARAM(pic_init_qp_minus26);
> > > +       GET_MTK_VDEC_PARAM(chroma_qp_index_offset);
> > > +       GET_MTK_VDEC_PARAM(second_chroma_qp_index_offset);
> > > +
> > > +       GET_MTK_VDEC_FLAG(entropy_coding_mode_flag,
> > > +               V4L2_H264_PPS_FLAG_ENTROPY_CODING_MODE);
> > > +       GET_MTK_VDEC_FLAG(pic_order_present_flag,
> > > +              
> > > V4L2_H264_PPS_FLAG_BOTTOM_FIELD_PIC_ORDER_IN_FRAME_PRESENT);
> > > +       GET_MTK_VDEC_FLAG(weighted_pred_flag,
> > > +               V4L2_H264_PPS_FLAG_WEIGHTED_PRED);
> > > +       GET_MTK_VDEC_FLAG(deblocking_filter_control_present_flag,
> > > +               V4L2_H264_PPS_FLAG_DEBLOCKING_FILTER_CONTROL_PRESENT);
> > > +       GET_MTK_VDEC_FLAG(constrained_intra_pred_flag,
> > > +               V4L2_H264_PPS_FLAG_CONSTRAINED_INTRA_PRED);
> > > +       GET_MTK_VDEC_FLAG(redundant_pic_cnt_present_flag,
> > > +               V4L2_H264_PPS_FLAG_REDUNDANT_PIC_CNT_PRESENT);
> > > +       GET_MTK_VDEC_FLAG(transform_8x8_mode_flag,
> > > +               V4L2_H264_PPS_FLAG_TRANSFORM_8X8_MODE);
> > > +       GET_MTK_VDEC_FLAG(scaling_matrix_present_flag,
> > > +               V4L2_H264_PPS_FLAG_SCALING_MATRIX_PRESENT);
> > > +}
> > > +
> > > +static void
> > > +get_h264_scaling_matrix(struct slice_api_h264_scaling_matrix *dst_matrix,
> > > +                       const struct v4l2_ctrl_h264_scaling_matrix
> > > *src_matrix)
> > > +{
> > > +       memcpy(dst_matrix->scaling_list_4x4, src_matrix->scaling_list_4x4,
> > > +              sizeof(dst_matrix->scaling_list_4x4));
> > > +
> > > +       memcpy(dst_matrix->scaling_list_8x8, src_matrix->scaling_list_8x8,
> > > +              sizeof(dst_matrix->scaling_list_8x8));
> > > +}
> > > +
> > > +static void get_h264_decode_parameters(
> > > +       struct slice_api_h264_decode_param *dst_params,
> > > +       const struct v4l2_ctrl_h264_decode_params *src_params,
> > > +       const struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES])
> > > +{
> > > +       int i;
> > > +
> > > +       for (i = 0; i < ARRAY_SIZE(dst_params->dpb); i++) {
> > > +               struct slice_h264_dpb_entry *dst_entry = &dst_params-
> > > >dpb[i];
> > > +               const struct v4l2_h264_dpb_entry *src_entry = &dpb[i];
> > > +
> > > +               dst_entry->reference_ts = src_entry->reference_ts;
> > > +               dst_entry->frame_num = src_entry->frame_num;
> > > +               dst_entry->pic_num = src_entry->pic_num;
> > > +               dst_entry->top_field_order_cnt = src_entry-
> > > >top_field_order_cnt;
> > > +               dst_entry->bottom_field_order_cnt =
> > > +                       src_entry->bottom_field_order_cnt;
> > > +               dst_entry->flags = src_entry->flags;
> > > +       }
> > > +
> > > +       // num_slices is a leftover from the old H.264 support and is
> > > ignored
> > > +       // by the firmware.
> > > +       dst_params->num_slices = 0;
> > > +       dst_params->nal_ref_idc = src_params->nal_ref_idc;
> > > +       dst_params->top_field_order_cnt = src_params->top_field_order_cnt;
> > > +       dst_params->bottom_field_order_cnt = src_params-
> > > >bottom_field_order_cnt;
> > > +       dst_params->flags = src_params->flags;
> > > +}
> > > +
> > > +static bool dpb_entry_match(const struct v4l2_h264_dpb_entry *a,
> > > +                           const struct v4l2_h264_dpb_entry *b)
> > > +{
> > > +       return a->top_field_order_cnt == b->top_field_order_cnt &&
> > > +              a->bottom_field_order_cnt == b->bottom_field_order_cnt;
> > > +}
> > > +
> > > +/*
> > > + * Move DPB entries of dec_param that refer to a frame already existing
> > > in dpb
> > > + * into the already existing slot in dpb, and move other entries into new
> > > slots.
> > > + *
> > > + * This function is an adaptation of the similarly-named function in
> > > + * hantro_h264.c.
> > > + */
> > > +static void update_dpb(const struct v4l2_ctrl_h264_decode_params
> > > *dec_param,
> > > +                      struct v4l2_h264_dpb_entry *dpb)
> > > +{
> > > +       DECLARE_BITMAP(new, ARRAY_SIZE(dec_param->dpb)) = { 0, };
> > > +       DECLARE_BITMAP(in_use, ARRAY_SIZE(dec_param->dpb)) = { 0, };
> > > +       DECLARE_BITMAP(used, ARRAY_SIZE(dec_param->dpb)) = { 0, };
> > > +       unsigned int i, j;
> > > +
> > > +       /* Disable all entries by default, and mark the ones in use. */
> > > +       for (i = 0; i < ARRAY_SIZE(dec_param->dpb); i++) {
> > > +               if (dpb[i].flags & V4L2_H264_DPB_ENTRY_FLAG_ACTIVE)
> > > +                       set_bit(i, in_use);
> > > +               dpb[i].flags &= ~V4L2_H264_DPB_ENTRY_FLAG_ACTIVE;
> > > +       }
> > > +
> > > +       /* Try to match new DPB entries with existing ones by their POCs.
> > > */
> > > +       for (i = 0; i < ARRAY_SIZE(dec_param->dpb); i++) {
> > > +               const struct v4l2_h264_dpb_entry *ndpb = &dec_param-
> > > >dpb[i];
> > > +
> > > +               if (!(ndpb->flags & V4L2_H264_DPB_ENTRY_FLAG_ACTIVE))
> > > +                       continue;
> > > +
> > > +               /*
> > > +                * To cut off some comparisons, iterate only on target DPB
> > > +                * entries were already used.
> > > +                */
> > > +               for_each_set_bit(j, in_use, ARRAY_SIZE(dec_param->dpb)) {
> > > +                       struct v4l2_h264_dpb_entry *cdpb;
> > > +
> > > +                       cdpb = &dpb[j];
> > > +                       if (!dpb_entry_match(cdpb, ndpb))
> > > +                               continue;
> > > +
> > > +                       *cdpb = *ndpb;
> > > +                       set_bit(j, used);
> > > +                       /* Don't reiterate on this one. */
> > > +                       clear_bit(j, in_use);
> > > +                       break;
> > > +               }
> > > +
> > > +               if (j == ARRAY_SIZE(dec_param->dpb))
> > > +                       set_bit(i, new);
> > > +       }
> > > +
> > > +       /* For entries that could not be matched, use remaining free
> > > slots. */
> > > +       for_each_set_bit(i, new, ARRAY_SIZE(dec_param->dpb)) {
> > > +               const struct v4l2_h264_dpb_entry *ndpb = &dec_param-
> > > >dpb[i];
> > > +               struct v4l2_h264_dpb_entry *cdpb;
> > > +
> > > +               /*
> > > +                * Both arrays are of the same sizes, so there is no way
> > > +                * we can end up with no space in target array, unless
> > > +                * something is buggy.
> > > +                */
> > > +               j = find_first_zero_bit(used, ARRAY_SIZE(dec_param->dpb));
> > > +               if (WARN_ON(j >= ARRAY_SIZE(dec_param->dpb)))
> > > +                       return;
> > > +
> > > +               cdpb = &dpb[j];
> > > +               *cdpb = *ndpb;
> > > +               set_bit(j, used);
> > > +       }
> > > +}
> > > +
> > > +/*
> > > + * The firmware expects unused reflist entries to have the value 0x20.
> > > + */
> > > +static void fixup_ref_list(u8 *ref_list, size_t num_valid)
> > > +{
> > > +       memset(&ref_list[num_valid], 0x20, 32 - num_valid);
> > > +}
> > > +
> > > +static void get_vdec_decode_parameters(struct vdec_h264_slice_inst *inst)
> > > +{
> > > +       const struct v4l2_ctrl_h264_decode_params *dec_params =
> > > +               get_ctrl_ptr(inst->ctx,
> > > V4L2_CID_STATELESS_H264_DECODE_PARAMS);
> > > +       const struct v4l2_ctrl_h264_sps *sps =
> > > +               get_ctrl_ptr(inst->ctx, V4L2_CID_STATELESS_H264_SPS);
> > > +       const struct v4l2_ctrl_h264_pps *pps =
> > > +               get_ctrl_ptr(inst->ctx, V4L2_CID_STATELESS_H264_PPS);
> > > +       const struct v4l2_ctrl_h264_scaling_matrix *scaling_matrix =
> > > +               get_ctrl_ptr(inst->ctx,
> > > V4L2_CID_STATELESS_H264_SCALING_MATRIX);
> > > +       struct mtk_h264_dec_slice_param *slice_param = &inst-
> > > >h264_slice_param;
> > > +       struct v4l2_h264_reflist_builder reflist_builder;
> > > +       enum v4l2_field dpb_fields[V4L2_H264_NUM_DPB_ENTRIES];
> > > +       u8 *p0_reflist = slice_param->decode_params.ref_pic_list_p0;
> > > +       u8 *b0_reflist = slice_param->decode_params.ref_pic_list_b0;
> > > +       u8 *b1_reflist = slice_param->decode_params.ref_pic_list_b1;
> > > +       int i;
> > > +
> > > +       update_dpb(dec_params, inst->dpb);
> > > +
> > > +       get_h264_sps_parameters(&slice_param->sps, sps);
> > > +       get_h264_pps_parameters(&slice_param->pps, pps);
> > > +       get_h264_scaling_matrix(&slice_param->scaling_matrix,
> > > scaling_matrix);
> > > +       get_h264_decode_parameters(&slice_param->decode_params,
> > > dec_params,
> > > +                                  inst->dpb);
> > > +       get_h264_dpb_list(inst, slice_param);
> > > +
> > > +       /* Prepare the fields for our reference lists */
> > > +       for (i = 0; i < V4L2_H264_NUM_DPB_ENTRIES; i++)
> > > +               dpb_fields[i] = slice_param->h264_dpb_info[i].field;
> > > +       /* Build the reference lists */
> > > +       v4l2_h264_init_reflist_builder(&reflist_builder, dec_params, sps,
> > > +                                      inst->dpb);
> > > +       v4l2_h264_build_p_ref_list(&reflist_builder, p0_reflist);
> > > +       v4l2_h264_build_b_ref_lists(&reflist_builder, b0_reflist,
> > > b1_reflist);
> > > +       /* Adapt the built lists to the firmware's expectations */
> > > +       fixup_ref_list(p0_reflist, reflist_builder.num_valid);
> > > +       fixup_ref_list(b0_reflist, reflist_builder.num_valid);
> > > +       fixup_ref_list(b1_reflist, reflist_builder.num_valid);
> > > +
> > > +       memcpy(&inst->vsi_ctx.h264_slice_params, slice_param,
> > > +              sizeof(inst->vsi_ctx.h264_slice_params));
> > > +}
> > > +
> > > +static unsigned int get_mv_buf_size(unsigned int width, unsigned int
> > > height)
> > > +{
> > > +       int unit_size = (width / MB_UNIT_LEN) * (height / MB_UNIT_LEN) +
> > > 8;
> > > +
> > > +       return HW_MB_STORE_SZ * unit_size;
> > > +}
> > > +
> > > +static int allocate_predication_buf(struct vdec_h264_slice_inst *inst)
> > > +{
> > > +       int err = 0;
> > > +
> > > +       inst->pred_buf.size = BUF_PREDICTION_SZ;
> > > +       err = mtk_vcodec_mem_alloc(inst->ctx, &inst->pred_buf);
> > > +       if (err) {
> > > +               mtk_vcodec_err(inst, "failed to allocate ppl buf");
> > > +               return err;
> > > +       }
> > > +
> > > +       inst->vsi_ctx.pred_buf_dma = inst->pred_buf.dma_addr;
> > > +       return 0;
> > > +}
> > > +
> > > +static void free_predication_buf(struct vdec_h264_slice_inst *inst)
> > > +{
> > > +       struct mtk_vcodec_mem *mem = NULL;
> > > +
> > > +       mtk_vcodec_debug_enter(inst);
> > > +
> > > +       inst->vsi_ctx.pred_buf_dma = 0;
> > > +       mem = &inst->pred_buf;
> > > +       if (mem->va)
> > > +               mtk_vcodec_mem_free(inst->ctx, mem);
> > > +}
> > > +
> > > +static int alloc_mv_buf(struct vdec_h264_slice_inst *inst,
> > > +       struct vdec_pic_info *pic)
> > > +{
> > > +       int i;
> > > +       int err;
> > > +       struct mtk_vcodec_mem *mem = NULL;
> > > +       unsigned int buf_sz = get_mv_buf_size(pic->buf_w, pic->buf_h);
> > > +
> > > +       mtk_v4l2_debug(3, "size = 0x%lx", buf_sz);
> > > +       for (i = 0; i < H264_MAX_MV_NUM; i++) {
> > > +               mem = &inst->mv_buf[i];
> > > +               if (mem->va)
> > > +                       mtk_vcodec_mem_free(inst->ctx, mem);
> > > +               mem->size = buf_sz;
> > > +               err = mtk_vcodec_mem_alloc(inst->ctx, mem);
> > > +               if (err) {
> > > +                       mtk_vcodec_err(inst, "failed to allocate mv buf");
> > > +                       return err;
> > > +               }
> > > +               inst->vsi_ctx.mv_buf_dma[i] = mem->dma_addr;
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +static void free_mv_buf(struct vdec_h264_slice_inst *inst)
> > > +{
> > > +       int i;
> > > +       struct mtk_vcodec_mem *mem = NULL;
> > > +
> > > +       for (i = 0; i < H264_MAX_MV_NUM; i++) {
> > > +               inst->vsi_ctx.mv_buf_dma[i] = 0;
> > > +               mem = &inst->mv_buf[i];
> > > +               if (mem->va)
> > > +                       mtk_vcodec_mem_free(inst->ctx, mem);
> > > +       }
> > > +}
> > > +
> > > +static void get_pic_info(struct vdec_h264_slice_inst *inst,
> > > +                        struct vdec_pic_info *pic)
> > > +{
> > > +       struct mtk_vcodec_ctx *ctx = inst->ctx;
> > > +
> > > +       ctx->picinfo.buf_w = (ctx->picinfo.pic_w + 15) & 0xFFFFFFF0;
> > > +       ctx->picinfo.buf_h = (ctx->picinfo.pic_h + 31) & 0xFFFFFFE0;
> > > +       ctx->picinfo.fb_sz[0] = ctx->picinfo.buf_w * ctx->picinfo.buf_h;
> > > +       ctx->picinfo.fb_sz[1] = ctx->picinfo.fb_sz[0] >> 1;
> > > +       inst->vsi_ctx.dec.cap_num_planes =
> > > +               ctx->q_data[MTK_Q_DATA_DST].fmt->num_planes;
> > > +
> > > +       pic = &ctx->picinfo;
> > > +       mtk_vcodec_debug(inst, "pic(%d, %d), buf(%d, %d)",
> > > +                        ctx->picinfo.pic_w, ctx->picinfo.pic_h,
> > > +                        ctx->picinfo.buf_w, ctx->picinfo.buf_h);
> > > +       mtk_vcodec_debug(inst, "Y/C(%d, %d)", ctx->picinfo.fb_sz[0],
> > > +               ctx->picinfo.fb_sz[1]);
> > > +
> > > +       if ((ctx->last_decoded_picinfo.pic_w != ctx->picinfo.pic_w) ||
> > > +               (ctx->last_decoded_picinfo.pic_h != ctx->picinfo.pic_h)) {
> > > +               inst->vsi_ctx.dec.resolution_changed = true;
> > > +               if ((ctx->last_decoded_picinfo.buf_w != ctx-
> > > >picinfo.buf_w) ||
> > > +                       (ctx->last_decoded_picinfo.buf_h != ctx-
> > > >picinfo.buf_h))
> > > +                       inst->vsi_ctx.dec.realloc_mv_buf = true;
> > > +
> > > +               mtk_v4l2_debug(1, "ResChg: (%d %d) : old(%d, %d) ->
> > > new(%d, %d)",
> > > +                       inst->vsi_ctx.dec.resolution_changed,
> > > +                       inst->vsi_ctx.dec.realloc_mv_buf,
> > > +                       ctx->last_decoded_picinfo.pic_w,
> > > +                       ctx->last_decoded_picinfo.pic_h,
> > > +                       ctx->picinfo.pic_w, ctx->picinfo.pic_h);
> > > +       }
> > > +}
> > > +
> > > +static void get_crop_info(struct vdec_h264_slice_inst *inst,
> > > +       struct v4l2_rect *cr)
> > > +{
> > > +       cr->left = inst->vsi_ctx.crop.left;
> > > +       cr->top = inst->vsi_ctx.crop.top;
> > > +       cr->width = inst->vsi_ctx.crop.width;
> > > +       cr->height = inst->vsi_ctx.crop.height;
> > > +
> > > +       mtk_vcodec_debug(inst, "l=%d, t=%d, w=%d, h=%d",
> > > +                        cr->left, cr->top, cr->width, cr->height);
> > > +}
> > > +
> > > +static void get_dpb_size(struct vdec_h264_slice_inst *inst,
> > > +       unsigned int *dpb_sz)
> > > +{
> > > +       *dpb_sz = inst->vsi_ctx.dec.dpb_sz;
> > > +       mtk_vcodec_debug(inst, "sz=%d", *dpb_sz);
> > > +}
> > > +
> > > +static int vdec_h264_slice_init(struct mtk_vcodec_ctx *ctx)
> > > +{
> > > +       struct vdec_h264_slice_inst *inst = NULL;
> > > +       int err;
> > > +
> > > +       inst = kzalloc(sizeof(*inst), GFP_KERNEL);
> > > +       if (!inst)
> > > +               return -ENOMEM;
> > > +
> > > +       inst->ctx = ctx;
> > > +
> > > +       inst->vpu.id = SCP_IPI_VDEC_H264;
> > > +       inst->vpu.ctx = ctx;
> > > +
> > > +       err = vpu_dec_init(&inst->vpu);
> > > +       if (err) {
> > > +               mtk_vcodec_err(inst, "vdec_h264 init err=%d", err);
> > > +               goto error_free_inst;
> > > +       }
> > > +
> > > +       memcpy(&inst->vsi_ctx, inst->vpu.vsi, sizeof(inst->vsi_ctx));
> > > +       inst->vsi_ctx.dec.resolution_changed = true;
> > > +       inst->vsi_ctx.dec.realloc_mv_buf = true;
> > > +
> > > +       err = allocate_predication_buf(inst);
> > > +       if (err)
> > > +               goto error_deinit;
> > > +
> > > +       mtk_vcodec_debug(inst, "struct size = %d,%d,%d,%d\n",
> > > +               sizeof(struct mtk_h264_sps_param),
> > > +               sizeof(struct mtk_h264_pps_param),
> > > +               sizeof(struct mtk_h264_dec_slice_param),
> > > +               sizeof(struct mtk_h264_dpb_info));
> > > +
> > > +       mtk_vcodec_debug(inst, "H264 Instance >> %p", inst);
> > > +
> > > +       ctx->drv_handle = inst;
> > > +       return 0;
> > > +
> > > +error_deinit:
> > > +       vpu_dec_deinit(&inst->vpu);
> > > +
> > > +error_free_inst:
> > > +       kfree(inst);
> > > +       return err;
> > > +}
> > > +
> > > +static void vdec_h264_slice_deinit(void *h_vdec)
> > > +{
> > > +       struct vdec_h264_slice_inst *inst =
> > > +               (struct vdec_h264_slice_inst *)h_vdec;
> > > +
> > > +       mtk_vcodec_debug_enter(inst);
> > > +
> > > +       vpu_dec_deinit(&inst->vpu);
> > > +       free_predication_buf(inst);
> > > +       free_mv_buf(inst);
> > > +
> > > +       kfree(inst);
> > > +}
> > > +
> > > +static int find_start_code(unsigned char *data, unsigned int data_sz)
> > > +{
> > > +       if (data_sz > 3 && data[0] == 0 && data[1] == 0 && data[2] == 1)
> > > +               return 3;
> > > +
> > > +       if (data_sz > 4 && data[0] == 0 && data[1] == 0 && data[2] == 0 &&
> > > +           data[3] == 1)
> > > +               return 4;
> > > +
> > > +       return -1;
> > > +}
> > > +
> > > +static int vdec_h264_slice_decode(void *h_vdec, struct mtk_vcodec_mem
> > > *bs,
> > > +                                 struct vdec_fb *fb, bool *res_chg)
> > > +{
> > > +       struct vdec_h264_slice_inst *inst =
> > > +               (struct vdec_h264_slice_inst *)h_vdec;
> > > +       struct vdec_vpu_inst *vpu = &inst->vpu;
> > > +       struct mtk_video_dec_buf *src_buf_info;
> > > +       int nal_start_idx = 0, err = 0;
> > > +       uint32_t nal_type, data[2];
> > > +       unsigned char *buf;
> > > +       uint64_t y_fb_dma;
> > > +       uint64_t c_fb_dma;
> > > +
> > > +       mtk_vcodec_debug(inst, "+ [%d] FB y_dma=%llx c_dma=%llx va=%p",
> > > +                        ++inst->num_nalu, y_fb_dma, c_fb_dma, fb);
> > > +
> > > +       /* bs NULL means flush decoder */
> > > +       if (bs == NULL)
> > > +               return vpu_dec_reset(vpu);
> > > +
> > > +       src_buf_info = container_of(bs, struct mtk_video_dec_buf,
> > > bs_buffer);
> > > +
> > > +       y_fb_dma = fb ? (u64)fb->base_y.dma_addr : 0;
> > > +       c_fb_dma = fb ? (u64)fb->base_c.dma_addr : 0;
> > > +
> > > +       buf = (unsigned char *)bs->va;
> > 
> > I can be completely wrong, but it would seem here
> > is where the CPU mapping is used.
> 
> I think you're right. :)
> 
> > 
> > > +       nal_start_idx = find_start_code(buf, bs->size);
> > > +       if (nal_start_idx < 0)
> > > +               goto err_free_fb_out;
> > > +
> > > +       data[0] = bs->size;
> > > +       data[1] = buf[nal_start_idx];
> > > +       nal_type = NAL_TYPE(buf[nal_start_idx]);
> > 
> > Which seems to be used to parse the NAL type. But shouldn't
> > you expect here VLC NALUs only?
> > 
> > I.e. you only get IDR or non-IDR frames, marked with
> > V4L2_H264_DECODE_PARAM_FLAG_IDR_PIC.
> 
> Yep, that's true. And as a matter of fact I can remove `nal_type` (and
> the test using it below) and the driver is just as happy.
> 
> > 
> > > +       mtk_vcodec_debug(inst, "\n + NALU[%d] type %d +\n", inst-
> > > >num_nalu,
> > > +                        nal_type);
> > > +
> > > +       inst->vsi_ctx.dec.bs_dma = (uint64_t)bs->dma_addr;
> > > +       inst->vsi_ctx.dec.y_fb_dma = y_fb_dma;
> > > +       inst->vsi_ctx.dec.c_fb_dma = c_fb_dma;
> > > +       inst->vsi_ctx.dec.vdec_fb_va = (u64)(uintptr_t)fb;
> > > +
> > > +       get_vdec_decode_parameters(inst);
> > > +       *res_chg = inst->vsi_ctx.dec.resolution_changed;
> > > +       if (*res_chg) {
> > > +               mtk_vcodec_debug(inst, "- resolution changed -");
> > > +               if (inst->vsi_ctx.dec.realloc_mv_buf) {
> > > +                       err = alloc_mv_buf(inst, &(inst->ctx->picinfo));
> > > +                       inst->vsi_ctx.dec.realloc_mv_buf = false;
> > > +                       if (err)
> > > +                               goto err_free_fb_out;
> > > +               }
> > > +               *res_chg = false;
> > > +       }
> > > +
> > > +       memcpy(inst->vpu.vsi, &inst->vsi_ctx, sizeof(inst->vsi_ctx));
> > > +       err = vpu_dec_start(vpu, data, 2);
> > 
> > Then it seems this 2-bytes are passed to the firmware. Maybe you
> > could test if that can be derived without the CPU mapping.
> > That would allow you to set DMA_ATTR_NO_KERNEL_MAPPING.
> 
> This one is a bit trickier. It seems the NAL type is passed as part of
> the decode request to the firmware. Which should be absolutely not
> needed since the firmware can check this from the buffer itself. Just
> for fun I have tried setting this parameter unconditionally to 0x1
> (non-IDR picture) and all I get is green frames with seemingly random
> garbage. If I set it to 0x5 (IDR picture) I also get green frames with
> a different kind of garbage, and once every while a properly rendered
> frame (presumably when it is *really* an IDR frame).

Can't you deduce this from the v4l2_ctrl_h264_slice_params.slice_type ?

> 
> So, mmm, I'm afraid we cannot decode properly without this information
> and thus without the mapping, unless Yunfei can tell us of a way to
> achieve this. Yunfei, do you have any idea?
> 
> Cheers,
> Alex.